nm0504: right er the subject this morning is an important one er i'm sure all lecturers tell you that er acute renal failure er i'm timetabled to have two sessions er but er unless you particularly want a break i was thinking of just merging it into one er see if you can concentrate for an hour and a half er acute renal failure before we talk about acute renal failure tell me what er tell me what medicine's all about what's medicine all about what's the point of being a doctor remember if you don't answer and i start picking on people sm0505: relief of symptoms nm0504: relief of symptoms yeah yep anybody else lady yawning here what's medicine all about sf0506: that's a vague question nm0504: it is it is in fact [laughter] very good in fact it's a vague question all right what i would say that er medicine is about biscuits er why is medicine about biscuits what happens when you make people better are they happy or sad speak up sm0507: happy nm0504: happy sf0508: depends on their quality of life nm0504: sorry sf0508: depends on their quality of life nm0504: depends on their quali-, that's a that's a good answer to do with their quality of life isn't it i mean a m-, you know if they tried to die of an overdose and you saved them they may not be very happy with you er i was on medical yesterday and er eight o'clock and get the violins out now violas whatever you like i was at the namex Hospital trying to save the life of a an eighty-two year old man who came in with a G-I bleed er aspiration pneumonia and was dying basically and he'd probably taken an overdose which is very sad at eighty-two and er i think he'd almost [cough] dead by this morning but er partly 'cause we allowed him to die and er that is quite sad actually you know why do eighty-two year olds take overdoses his wife said there were financial problems the business had gone bankrupt and you know i'm sure if he goes to I-T- U and stays there for a couple of weeks and survives he won't be very happy with us because er i'm pretty sure he wanted to die he he took er an overdose three years ago and i don't know why i'm telling you this but biscuits yeah so if you make people better they buy you biscuits and that's why i brought some along this morning just to er remind you what medicine was all about in my opinion it's about biscuits er biscuits because people are generally happy when they make you better er very important when you're looking after a patient to specify what type of biscuits you want otherwise you just get bog standard old rubbish from s-, ASDA or somewhere like that [laughter] so you must specify at the start when you go and see exactly what biscuits you want Marks and Spencer's every time [laughter] okay so er it's not just about biscuits though er it's actually quite good making people better and er you're wondering what on earth this has got to do with acute renal failure well i'm getting round to it in my long and convoluted way er making people better is good er i've been doing it for nearly twenty years and it still gives me a buzz when you leave the hospital at like eight ten o'clock whenever you leave the hospital er you do know it's not a nine to five job don't you you do know that you are aware of that [laughter] and er just to get that imprinted in your brains at an early stage and er your careers will not progress if you consider it a nine to five job er don't think that has changed either but when you leave the hospital at eight ten o'clock at night and a patient or more often the relative of a patient grabs your hand and says thank you doctor you saved my life or my husband's life or my wife's life that still gives you a kick even twenty years later and er one of the ways in which kidney doctors get a kick is the handshake when you've got somebody through acute renal failure er i think it's possibly because from the patient's perspective acute renal failure's a bit like a dream and er they know they're ill they don't know how ill they are they usually nearly meet their maker er and if they get better they don't quite know what's happened but they know something very bad has happened and in fact most body systems failure patients don't remember they're that ill whether it's respiratory failure cardiac failure or renal failure obviously my specialty's kidneys acute renal failure er like most failures is very bad for you er it's probably got a near hundred per cent mortality if you do nothing and you'll notice on on the handout have you all got a handout there is a handout anybody put your hands up if you haven't got a handout okay you'll see er fact number one at the top of your handout is kidney failure's very bad for you er even in two-thousand-and-three fifty per cent of people died er and that hasn't really improved since the nineteen-sixties so hundred per cent or nearly hundred per cent die if you do nothing fifty per cent die if you do something so there's not a great strike rate er there aren't too many handshakes and there aren't that many biscuits but you must specify on your biscuits er just let's talk a little bit er about a few words and and the word failure er traditionally in in talks such as this you don't start with outcomes you start with definitions and standard things like that but i thought the outcome of acute renal failure is so bad i thought you'd better know it is so bad because a lot of people think oh it's all right have a bit of dialysis they all get better and that that really isn't true even with dialysis the mortality's fifty per cent so the word failure let's have the lady in pink at the back there tell me about the the word failure and what do you think the patients what's your me-, what's your understanding of the word and and what do you think the patient's perception is sf0510: that it's not working any more nm0504: yeah and how much is it not working sf0510: quite a bit nm0504: quite a bit and patients normally perceive the word failure to mean complete failure you know if you say your car has failed that means it doesn't drive or the washing machine has failed it means it doesn't work and you can't put your clothes in the washer any more and if you use the word failure and if you think about it i think you've probably already started to use the word failure has anybody seen a patient yet and those that the F word come out has anybody said heart failure congestive cardiac failure and ha-, has anybody said that in front of a patient lady in pink nodding there anybody else said the word failure with a patient around them read in the notes said oh i see you've got heart failure oh bloody hell bit of nodding okay er i'd avoid the word failure i think that's what i i'm getting at in my long and convoluted way it implies absolute failure okay if there is absolute failure use it but if there isn't absolute failure don't use it diabetes is not absolute failure of the pancreas and we don't call it pancreatic failure it's partial pancreatic failure if you think about it if you have complete failure of any major body system you're dead you can't live very long with complete liver failure complete heart failure complete pancreas failure complete et cetera et cetera and k-, the kidneys are no different and absolute complete anuric zero kidney failure is almost unheard of now i say almost unheard of because as you know i'm sure you've heard this old maxim by now always and never are words a good doctor never uses ha ha er but that there is some truth to that there is no always and never in medicine there's no always and never in nature there's no always and never in life these are not words that we are familiar with in medicine and if you find yourself using them you probably don't understand what you're talking about er so try to avu-, avoid the word failure so lady in the pink doing well so if you're not going to talk about failure to a patient what what can you say sf0510: impairment nm0504: impairment Guardian all right sm0511: dysfunction nm0504: dysfunction ooh yeah New Scientist bit no [laughter] you know man on a on the bus you know they don't understand dysfunction dysfunctional families but but er what's what's another way of talking to a patient a-, about a bit of them that doesn't work what l-, what language can we use gentleman there sm0512: can you explain that it isn't working as well as it could be nm0504: mm just use simple words it's not working as well as it could be okay er you can give a percentage if you like and it's made up seventy-five per cent dysfunction but er what's the problem with percentages lady here sf0513: nm0504: they're not that accurate i mean they're but we we made up some of the numbers i mean deeper level they don't exist but what else is wrong with percentages i mean we talk in percentages all the time don't we sf0514: they don't mean much to patients nm0504: they don't mean much to the patient why don't they mean much to the patient sf0514: it's giving nm0504: yeah exactly and you know most of the older generation i don't know what that is don't understand percentages what do they what do they understand sm0515: fractions nm0504: fractions yeah try to talk in fractions if you want to talk in numbers you know or talk what's another way of expressing a fraction in in common language you're obviously a very clean-living lot never put a bet on ss: odds nm0504: odds yeah two to one three to one and that's the type of language people understand they don't okay you understand percentages and you can expect an educated person of your age but a less educated person of your age won't understand percentages they understand football league tables and they understand fractions and they understand odds but they don't necessarily understand percentages er so be careful if you talk about dysfunction and seventy-three per cent dysfunction doesn't mean r-, mean very much to most patients now the reason i'm emphasizing this point er i-, is that you can cause a lot of mental pain just by talking about failure and talking about percentages and and you know they don't understand it er and then you've got to be careful so as the gentleman said there no you know your kidneys don't work and they'll say well how bad are they and you can say well very bad or bad or quite bad use words they understand if they want some data try and give it to them in language they'll understand and it may be that if they're a University of namex professor of economics you can say seventy-four per cent function or dysfunction or whatever er what's the other problem with the word failure apart from the fact that they assume that means complete failure when a thing has failed completely it may not sm0516: work again nm0504: work again okay so it always implies that but but we know many body systems can recover the liver is a classic organ that recovers of its own accord i wish the kidney did but er so when a patient's in heart failure it may not be permanent heart they may just had an M-I last night a tachyarrhythmia and they may be fine by the morning with a bit of frusemide and a bit of digoxin so it also implies that you could never going to work again and when somebody's fighting for their life you mustn't r-, remove all hope from them because it's hope that's keeping them alive so if somebody's had an M-I and they've gone into heart failure and they're panting away and feeling awful and sweating and everything and they're about to have an arrest and you're going to shock them and then they'll come back but at that point they don't know that's going to happen and if you say to them i'm terribly sorry Mr Jenkins you've got complete heart failure er they'll think bloody hell bloody hell f-, that's bad isn't it and my heart doesn't work it's never going to get better so i might as well pop my clogs and you you must never remove a patient's hope and in the acute situation language is important okay so i don't have er a word or a phrase for you invent your own one you know talk in language the patients understand and hopefully that that you understand okay so we haven't got very far we're still on point point one outcome with drugs drugs drugs drugs drugs you'll notice that a theme of this talk is going to be drugs er drugs are very important both recreational and non- recreational er drugs are very important in terms of renal disease because they are a cause in part of up to thirty per cent of people with acute renal failure and rather worryingly er this is a little maxim that er an intensivist taught me when i was at an S-R at at King's in London if you're on I-T-U and you're on a ventilator and your kidneys go down you have eighty per cent mortality you're on a very low chance of leaving that I-T-U if you develop one more body system failure up you're up to ninety one more and you're bust a hundred per cent mortality so having kidney failure on an I-T-U is a very very bad sign er we don't quite know why there's been a lot of research in the last few years of of of why kidney failure on in the I-T-U setting is such high mortality and it may be very simple you know if you've been smashed to bits in a road traffic accident you've got five fractures and a ruptured spleen your head's come off and you've got no arms you know the i-, it is bad for you it's bad for the health to be involved in that road traffic accident but but we don't really know why you read in whatever you read in these is such a bad thing but that's quite a useful maxim if you ever go on to an I-T-U and you're trying to er talk to a patient or probably not to the patient but talk to the family about are they going to live doc and and i start adding up the failures in my head when i start talking about little chance of survival but there is s-, some hope or a small chance of survival and if they ask what the percentages are i'll give it to them okay so def-, definitions definitions i think you know by now i'm not very keen on definitions and most things are indefinable er and before you read the definition on that handout what would you have guessed might have been in the er gentleman on the end there what might you have guessed er as the definition of acute renal failure sm0517: er an inability for the kidney to function nm0504: yeah i mean that's probably as good as any er i'm sure you might want to slip the creatinine into your definition wouldn't you sm0517: yeah nm0504: you probably would er don't is the go home message er the creatinine and the urine output have nothing to do with the desh-, definition of of acute renal failure certainly when i was a student i i always was pestering them okay well what was bad you know what what's normal what's bad and what's failure er there's no such thing because remember as i talked about before how we get normal ranges you know we measure creatinine in a lot of people and we stick everybody within two standard deviations the mean within that normal range so perfectly normal people have a creatinine of a hundred-and- thirty remember the magic number up up to a hundred-and-twenty it's just voodoo hundred-and-twenty creatinine hundred-and-twenty er G-F-R it's the only number you need to remember to be a kidney doctor or know anything about the kidney and that voodoo is not there in the States and other countries where they use other units but it the voodoo is there the hundred-and-twenty number so it is almost impossible to define because people's baseline creatinine is variable and what does the creatinine your baseline creatinine depend on sm0518: er the muscle bulk nm0504: yeah your muscle bulk mainly your muscle bulk so age sex mass muscle bulk use of muscles so i'm sure Jonah Lomu before he got kidney failure had a normal creatinine of a hundred-and-thirty and that could either have been a hundred-and-thirty because it's within statistical error or it could be genuinely a hundred-and-thirty because he's a big bloke and has big muscles how on earth he plays top class rugby i've got no idea on dialysis but he does seem to er so it's very difficult to define according to a certain number and it's more important whatever your baseline is and movement from the baseline that if if you want a number i've copied a definition out of a book there for those of you who who cannot leave this room without some form of number in their head er a recent rise of fifty micromoles per litre of creatinine er if the baseline is less than three-hundred over hundred it's over over three- hundred you can learn that if you like i took it out of a book i'd forget it just remember that it's indefinable and movement away from the baseline is the important thing why does oliguria let's have this gentleman here why does that play no part in the definition of of acute renal failure sm0519: er well you well i don't know er well you you hope that your kidneys are er filtrating nm0504: yeah okay you're getting there so how do you know that that nice glass of red wine there is a good glass of wine sm0518: er the colour and er the smell nm0504: and what do you need to do sm0518: taste it nm0504: you need to taste it don't you it may look all right and urine may look all right i'm not advocating you drink urine [laughter] but but you but you've got to taste it haven't you and and what urine is like wine it's all about quality and so you could be passing ten litres a day and if it's it's of low quality if it's not getting rid of urea creatinine phosphate potassium all the rest of it then it's not good urine so you have to know what's in it and that's why oliguria and there are plenty of people with non-oliguric or even polyuric acute renal failure okay er so we're saying it's indefinable we're saying that er movement from the baseline is important but that does mean that a little old lady with no muscle bulk if we're taking the normal range to be sixty a hundred-and-twenty for example a little old lady may have a creatinine of baseline creatinine of forty partly out of statistical error or partly because she genuinely does because she's a little old lady who doesn't have very big muscles and doesn't use them er and that's why it's always important to look back through the notes if the patient's had bloods done ten years ago twenty years ago er then seek them out in the notes they won't be on the computer system right epidemiology we mentioned a lot about epidemiology er if you want to make yourself famous do a PhD on epidemiology of acute renal failure nobody's ever done one er i think it's the only major body system failure where nobody's ever looked into it in an-, any great detail i don't know why er perhaps because it's a relatively rare diagnosis actually it isn't that rare about thirty per cent of people entering hospital on a medical or surgical take have a raised creatinine i'm not saying they've got kidney failure they may have renal impairment for a period of time before you give them normal and before the creatinine is normal and it fails and a raised creatinine on admission to hospital is extremely common and surgeons don't ring us every time somebody has a raised somebody has a raised creatinine level they'd be ringing us all day long every day they note the creatinine's really abnormal on the first day they give the patient fluids give the creatinine the next day and if it's come down fine if it's not come down give us a ring although they should give us a ring so we know very little about the epidemiology of acute renal failure er i've listed some risk factors there and if you look down those risk factors they're the sort of standard risk factors that you know of anything really aren't they diabetes old you know pre-existing failure er and the the one theme that comes through those risk factors i think is atheroma w-, why why is it atheroma's important let's have this lady here why do you think atheroma's important sf0520: er in acute renal failure nm0504: yeah or predisposing to acute renal failure sf0520: well blood flowing into the kidney is going to be hindered nm0504: yeah very good so you know if somebody has pre-existing renal vascular disease then they may already have partial blood flow to the kidney and then if another event happens if another insult happens they're more likely to get acute renal failure er and there are some worrying statistics i've put down for you there er there have been studies done of angiography both of angiography of the legs and angiography of the heart and if you look hard enough if you do a cardiac angiogram or a leg angiogram for no kidney reason and you happen to squirt some dye down the kidneys about fifty per cent of people will have radiologically significant renal vascular disease so er and not know it they may have a normal creatinine er but it is there and so most of the patients out there in the ether the type of patient you're looking after are sitters for acute renal failure or more commonly acute onchronic renal failure which is sometimes er written as A- C-R-F rather than A- R-F okay er trauma why does trauma cause kidney failure let's have the gentleman right at the back there why does trauma sm0521: er direct damage to the blood vessels nm0504: er yeah no good point actually yeah possibly er i mean yeah if if you avulse your er renovascular bed then that's not very good for you and that can happen it's quite hard to damage the kidneys as you know they're behind the ribs there and you have to really try hard to damage somebody's kidneys they are sometimes damaged in road traffic accidents but not very commonly 'cause they're at the back you're more likely to cause trauma to the front er you know some violent sports you're get punched or kicked or baseball batted in the in in the kidneys but er apart apart from that any any any other ways in which trauma can cause acute renal failure sm0522: nm0504: speak up anybody else sm0523: sf0524: nm0504: er yeah good yeah yeah yeah yeah sm0525: nm0504: yeah very good rhabdomyolysis er and er the study of acute renal failure in war has led us to er a much greater understanding of the pathophysiology we still don't understand it but a lot of important research came out of the Vietnam War er in terms of acute renal failure and there's nothing like a good war to improve doctors' understanding of disease er and rhabdomyolysis which can come on secondary to any form of of muscle trauma er whether it be spontaneous muscle trauma alcoholics for example drugs can spontaneously develop what's called compartment syndrome and from that develop rhabdomyolysis and that go acute renal failure or you can non-spontaneously you know a bus hits you you played rugby et cetera et cetera and you damage your muscles in some way er pregnancy pregnancy [sigh] the only interesting thing in from my perspective about pregnancy is the fact that they get kidney failure er when do they get kidney failure why gentleman there on the right when do pregnant women get kidney failure sm0526: er during hypertension nm0504: yeah yeah d-, is it hypo or hyper sm0526: hyper nm0504: hyper yeah i mean why do they get hypertensive sm0526: it's a a complication of pregnancy nm0504: yeah very good [laughter] okay it is a complication of pregnancy er particularly er the last trimester er pre-eclampsia or eclampsia these are these are names we call for a specific syndrome which incorporates kidney problems and hypertension er bleeding you know ab-, ab-, you haven't done your obs and gynae yet have you sm0527: no nm0504: no you will do obs and gynae you will go to deliveries it's very messy there's blood everywhere er it's very exciting yes i cried at my first delivery yes most of you will all those hard men though you'll all cry too it is an amazing experience seeing a baby born but er it's very bloody er and there is blood loss even with a a normal delivery er so there are a lot of reasons that a woman can go into acute renal failure pre-eclampsia eclampsia blood loss but there's also a specific syndrome er it goes by a variety of names pregnancy-related acute renal failure there's a load of other names for it some people say it doesn't really exist and it's actually just a variant of pre-eclampsia but there certainly is a syndrome it can come on even after delivery er of acute renal failure the aetiology of it is not really understood it's something to do with pre-eclampsia it's something to do with microangiopathic haemolytic anaemia it's something to do with low platelets it's something to do with kidney failure and this triad of haemolytic anaemia acute renal failure low platelets you'll see in many bits of medicine er dermatologists will stand here and talk about scleroderma causing i-, an intensivist D-I-C a blood pressure doctor malignant hypertension a pregnancy doctor er pregnancy-related or acute renal failure HELP syndrome to a ler-, liver doctor if you think about it these things are all the same or they're they're probably a final common pathway from from endothelial damage fascinating subject can't go into it today i'm afraid er i hope somebody else will okay er so there are certain patients that we know get kidney failure they're sitters for it pregnant women people who've had road traffic accidents trauma old people et cetera et cetera it is however traditional to talk about the causes of acute renal failure and er i'm going to try to present this in a in a different way or hopefully a different way but can you could you read that at the back my writing okay er tubes you remember what i said the kidney was it's a tube with a sieve in the middle and a way of sending the blood back er if you think about it that's actually also what a liver is and what a heart is what's a heart oh well it's a sort of a pump thing isn't it with a few chambers and blood goes into it and blood comes out oh yeah that's actually what a liver is isn't it but there's two sources of blood and then blood comes out of it they're all tubes i mean there are embryological reasons why they're tubes they started off as tubes er and they've become other things and rather than think of the kidney in the traditional way of being a kidney-shaped thing with blood going to it and from it and i'd like to try to change your mental image by unravelling that in your head and thinking about it as a tube having said that because i think then you'll understand the physiology and the pathophysiology more if you are going to think about the causes of acute renal failure sometimes a good old-fashioned diagram such as this is still useful because traditionally we talk about the causes as being pre as being renal and being post-renal but equally you could get rid of that and draw a tube and draw your sieve and talk about prerenal renal and post-renal you could also get rid of that and talk about a liver not a very good liver and talk about a tube as well how can the liver be extended to this analogy in terms of liver failure that lady at the front there we're going to in a minute we're going to talk about kidney failure but let's just go a bit left field field ho-, how can the traditional way of describing kidney failure be extended to another tube the liver speak up in other words what three groups of causes of liver failure do you know it's not a trick question not a Dr namex trick one it's a simple question so the liver's a thing where there's two sources of blood to it there's one source away on sm0528: pre prehepatic hepatic and nm0504: yeah so we talk about it in the same way so we talk so what's an example of a prehepatic cause of liver failure sm0529: haemolytic anaemia nm0504: haemolytic anaemia okay hepatic sf0530: hepatic nm0504: speak up ss: nm0504: cirrhosis did somebody say sm0531: yeah nm0504: okay so there's something wrong with the liver itself post-hepatic ss: nm0504: okay i mean yes it is a bit more complicated syndrome there are other ways of thinking about obstruction of the liver but the analogy runs for a liver and it runs for a heart and it runs for a kidney and although the topic of today's talk is kidneys so we'll go back to the kidney er and the classical way and i think it's still useful of dividing up the causes of kidney failure into pre renal and post-renal so rather than take a big book and look at the lists of causes of renal failure the lists of causes of liver failure try to work it out conceptually in your head and you won't have to learn the lists and also if if you find you've got to learn a list then you're going to forget it anyway the next day or you can just remember it for the exam so it's not a good way of learning learning lists okay so i've listed there three types of prerenal failure one true volume depletion two generalized ischaemia three local ischaemia so i'm doing a bit too much talking let's have the gentleman at the back there with the black top on on the right tell me about er volume depletion what do i mean by that and and what are some examples sm0532: well nm0504: speak up so we can hear sm0532: it's just a depletion of the circulating extra ex-, circulating round nm0504: yeah okay and and and what can cause volume depletion sm0532: cardiac failure er sorry cardiac heart failure nm0504: you speak up yeah sm0532: heart failure nm0504: yeah yeah very good i mean har-, i'm glad you said that i mean i'm glad you didn't say that what you would normally say which is bleeding i mean bleeding yes perhaps is the most common and the most one of the most simple to understand but heart failure isn't but it's actually it's the same thing in some ways and the body's pathophysiological reaction to heart failure is the same as bleeding and i'll come back to that so you can become volume deplete if you lack fluid in the body you may lack blood if you're bleeding as the gentleman at the back said you may lack fluid of other types such as extracellular fluid such as er er interstitial fluid in in various failures such as heart failure oh pen's running out er break for a new pen make sure that works yeah er or you may lack plasma or o-, other substances and the treatment of volume depletion depends on what you lack so if you're bleeding you treat the patient with blood if you've got heart failure are they truly volume deplete well they are in terms of how the body perceives the problem but the treatment is not to give them fluids but if they are volume deplete because of pancreatitis or a burn pancreatitis or so-called intra-abdominal burn then you may want to give them what they lack which is plasma but either way in all er four of these examples the patient is i knew this would happen i had a nice pen [sigh] oh i've ruined the board forever [laughter] [laughter] okay we'll ignore that bit [laughter] er so let's talk a bit more about th-, this whole idea of of volume depletion er it certainly was something i i didn't understand as a medical student and i think i'm only just starting to understand it now er true volume depletion or what we normally consider true volume depletion is typified by something like bleeding or diarrhoea or polyuria where you are genuinely losing fluid outside your body and that's why i've written on your handout there is a concept of true volume depletion now a more important concept is relative volume depletion relative volume depletion is a bit harder to understand but is a nic-, an example of it is heart failure as the gentleman said at the back and by relative volume depletion what i mean is fluid in the wrong compartment and heart failure is a classic example you've got fluid around your ankles you've got low blood pressure your heart doesn't work you can't pump blood or plasma or anything round your body and you are intravascularly dry you are volume deplete but the treatment is not to give them more fluid because they they've got an excess of fluid anyway so you have this rather odd situation where you can be if you like generally overloaded with extra water in the body but it's in the wrong place so it's not in the intravascular compartment where it should be so this it's quite difficult to get your head around an idea where you can be both wet and dry at the same time and you say well you can't you know you can't be black and white at the same time you can't be fast and slow at the same time and but in terms of fluid shifts you can be both actually it's taken me a long time to realize this i used to think you ha-, you you've got to be wet or dry but you can be both it depends how you get your head around it er you could say the purist would say of course that somebody who is fluid overloaded due to heart failure or liver failure or any other failures is not dry they can't be dry because they've got ankle swelling and they've got fluid in the lungs but the you can be intravascularly dry and peripherally wet and the body's reaction is the same which is often acute renal failure why is this why am i rabbiting on about this so much wh-, wh-, why is it such an important distinction in terms of of of of treatment that lady in the blue there sf0533: er is it if it's true er volume depletion then you can replace it nm0504: very good and sf0533: but if it's er relative you can't nm0504: you can't and sf0533: just get volume overload if you nm0504: correct absolutely and er you've got to correct the underlying problem so as in heart failure they give you a heart or er boost the heart or liver failure you need a liver or whatever or you need to tide them over while the heart recovers or the liver recovers but er the treatment is quite different a-, and the principles i mean sometimes we cover our bases when we're not sure we do what i call a push me pull you which we give them fluids and frusemide which is completely illogical and defies all physiology and pathophysiological textbooks but you know we know it works we i call it a push me pull you er okay there is a concept that the Americans have come up with which is called third spacing er i mention it partly because you may hear of it but i'd i'd rather like you to forget about it and and try to think of it i-, in this more simple way i don't know what the third space is i think what the Americans mean by third spacing is either true or relative volume depletion causes of of volume depletion in an area of the body you can't see er so what's an example of a true volume depletion leading to so-called third spacing what w-, what do you think the first and second spaces are we talk about the third word come on who did what's the first word sm0534: is it going to be something like inside the blood vessels and the in the extracellular fluids nm0504: yeah i mean basically yes i mean you have things in the cells and outside the cells er i think i think that's what the first and second space is i'm not absolutely sure i've never seen it defined but if er but the you know the Americans have come up with this idea of a third space i think it's a bit like the Third World it's a pile of bollocks you know and [laughter] i'm not meant to swear on video but [laughter] the the er it it's er okay so just take it as read that this concept exists er w-, er what what would be an example of it true volume depletion in an area of the body you can't see feel touch perceive think of hidden bits of the body sf0535: G-I bleed nm0504: yeah yeah yeah very good G-I bleed i'm glad you said that because people don't think about the early stages of a G-I bleed when the blood has gone out of the body or gone out of the wrong bit the right bit of the body and it's just sitting around in the bowel waiting to come out if you're bleeding slowly it may take a long time to come out and there's often a twenty-four forty-eight hour delay before you start seeing melena for example there are other spaces aren't there the abdomen there's a big hole in the abdomen pancreatitis classic example of a third space cause of true volume depletion burns well you can see burns maybe that's not a third spacing can you think of another space sm0536: lungs nm0504: lungs yes very good you can bleed in the lungs and not know it fractures fractures are probably the the classic example of third spacing particularly beware the fractured femur in an apparently fit young man after a game of rugby or football they may be bleeding pints into their thigh and you'll not see it they've got big thighs and they don't notice it they're bleeding into their bones remember the bone is not a bunch of calcium it's a it's a vascular organ so there are areas of the body where you can easily hide blood so maybe this does exist er and er which is part of the reason i'm i'm talking about it today of course third spacing could be relative volume depletion you know it is possible that i've said you can have fluid in the wrong space the wrong space can be invisible er i just can't think of an example of the one at the moment but usually third spacing is i think a variant of true volume depletion okay so generalized ischaemia this is a bit simpler to understand and is really the causes of low blood pressure there are only seven major causes or groups of causes of low blood pressure of shock or hypertension and i and i've listed them there er but anything that causes low blood pressure around the body is also going to cause low blood pressure in the kidney so any cause of low blood pressure can cause kidney failure this er concept of renal ischaemia is is a bit harder to to understand and you can understand it in a simple way just thinking well if you've got something blocking say even a partial renal arteriosclerosis then you get a thrombosis or you you've got a renal vein thrombosis er that's easy to understand er but that structure function can go wrong here too and i'm not going to go into it today but there are a whole range of drugs that can affect the renal artery or more particularly the afferent and efferent er capillary to the glomerulus er such as non-steroidal such as ACE inhibitors such as they're all i can think of at the moment er so both the structure of the renal artery vein and the function of the renal artery of the vein can be affected and if you think about it there must be a disease you know generally speaking if the if you can conceive a disease in the body it's almost certainly possible and it has happened at some point or it will happen at some point in the future er renal renal causes of acute renal failure are rare these ones are the common ones and the they make up ninety per cent of what we see in the hospitals the renal causes which is er part of the reason or the main reason why most kidney doctors go into kidney medicine er are extremely rare and if you're a G-P you might see one in your whole lifetime and having said that er when you get one it's very exciting and remember what i said that the kidney's a tube er with a with a sieve in the middle when we talk about the renal causes of acute renal failure we're largely talking about the sieve or problems on the other side of the sieve in other words the glomerulus or the tubules of the kidney the proximal the distal convoluted tubule the collecting tubule et cetera et cetera er and so you therefore have diseases such as acute glomerulonephritis acute vasculitis acute interstitial er nephritis and these are all autoimmune inflammations of either the glomerulus or the drainage system of the kidney and again today i'm not going to go into them in any gree-, great detail they are the thing we get excited about they are the thing we jump up and down about they are the thing that gets a kidney doctor most excited as i said last time but they're not that important in the real world Wegener's granulomatosis is a nice phrase er it's complicated er we talk about this endlessly on on er kidney ward rounds is this a case of Wegener's granulomatosis or a case of polyarthritis nodosa and what would Dr Wegener the number of old git nephrologists who've actually said to me what would Dr Wegener say you know i don't know what he would have said it doesn't matter it's not a common cause of acute renal failure er what is a more important cause is what i call established renal failure now you'd have to forgive me er in-, inventing a few words or inventing a few phrases and this is a Dr namex invention the concept of established renal failure it's not in your books it doesn't exist i'm telling you it probably exists why 'cause i've got the microphone er i don't like the phrase acute tubular necrosis and in some ways this is analogous or perhaps it is acute tubular necrosis gentleman at the back on the left there what's wrong with the phrase acute tubular necrosis have you heard of the phrase sm0537: no i've not nm0504: okay [laughter] we'll we'll er let's have a l-, lady with the with the light blue T-shirt on there have you heard of the phrase of A-T-N sf0538: er no nm0504: oh you must have heard of it lady in the red there no nobody's heard of that phrase seriously come on sm0539: it suggests that the tubule is completely dark nm0504: yeah that's the problem i mean you ha-, if you look in your renal book you'll be on chapters on acute tubular necrosis it it it suggests that necrosis happened that acute it's acute tubules there's a problem with the tubules they're all dead and and lady in the red there red top with er long hair what er sf0540: nm0504: why er i always stop people talking don't worry [laughter] er what's what's wrong with using a pathological phrase it's a pathological phrase acute infarctal cirrhosis we use them all the time don't we myocardial infarction we don't do heart biopsies we don't know if they're infarcted or not sf0540: it's not suggestive of what's actually happened nm0504: yeah it doesn't really tell you about absolutely about the pathophysiology which is much more important than the nephrology er the the the it's the pathophysiology that'll help you understand er how diseases happen and also how it's taught to patients you don't tell them you know you could be the world authority on the Kimmelstiel-Wilson disease try explaining that you know to Joe Public it's impossible but you might be able to explain diabetic nephropathy if you talk about the kidneys and blood sugar and damaging the kidney et cetera et cetera er and the same is true of a-, acute tubular necrosis that's why i don't like it there is another phrase which is acute tubular damage you may hear that phrase and that's a slight you know if you want a pathological phrase but these patients don't get renal biopsies and we don't know they've got acute tubular necrosis we don't know they've got acute tubular damage it's just a presumption er i'm going to come back later on and talk to to this differentiation between prerenal failure and Dr namex's established renal failure in a bit more detail okay post-renal i'm not going to talk about in any great detail i think it's covered later on today er and is in some ways the simplest to understand if er when one of you is very naughty later y-, later on and we take you down the front and operate on you in front of everybody else and tie off your ureters and er absolutely or cut the ureters there are absolutely zero i mean no possibility of any urine going from the kidney to the bladder that's obstructive nephropathy that i understand that's simple actually it's like minijoke what are what are the er three operations that a a gynaecologist is competent at have you heard this one oh come on [laughter] well they can either tie off one ureter the other ureter or both they're the three operations that a [laughter] that a a gynaecologist is competent at and er if if you er er give me a few drinks i'll tell you about some things they are less competent at [laughter] the er so er and this does happen actually they do tie off ureters i mean i i i i don't know how i mean i thought you know God if you believe in God made kidneys be yellow and arteries red veins blue and you know this is easy you go in there you know tie off the red ones [laughter] blue ones you know but you don't you don't sort of put a stitch round the yellow one but if only it was so easy and it is apparently very easy to tie off a ureter and i certainly have seen patients and one poor woman who was unlucky enough to have one kidney and the went on some vaguely minor or from a man's perception minor hysterectomy and [laughter] er in the end they er so they actually she she went in for something i can't remember and she was unfortunate enough to have one kidney and he tied off the ureter [laughter] that patient was in true proper obstructive nephropathy zero renal output we like that i've never seen that before [laughter] er and that was one of the reasons that made us think that the surgeon had had committed an error okay slight aside er if only it was so easy er actually obstructive nephropathy i don't know if if the following lecture's going to go into this in great detail it's very difficult to understand because if you think about it it usually isn't complete obstruction er we know that because we see it all the time it's it's one of the commonest causes of both acute and chronic renal failure and they don't have zero renal output in fact if anything they're usually polyuric and for reasons we don't understand partial obstruction to the ureter or the drainage system to the kidney at some level doesn't normally cause er oliguria it's for some reason again this is nobody's ever worked this out do a PhD work out the pathophysiology of obstructive nephropathy save the world er it's very very interesting having said all of that what do i actually see in my normal life do i see people with Wegener's granulomatosis do i see people with their kidneys tied off by a gynaecologist no i don't what i actually see is what i call the surgical cocktail don't tell that to the surgeons the surgical cocktail is three things and this is the mantra i want you to recite in your head every night dry sepsis drugs dry sepsis drugs dry sepsis drugs that is the mantra that is what surgeons do after the operation dry sepsis drugs why how does that happen gentleman perceptive gentleman at the back on the right why how do surgeons cause a patient to be dry septic and have drugs sm0541: 'cause they bleed nm0504: they bleed so they become dry yeah sm0541: er they're open so they get septic nm0504: speak up sm0541: they're open so they get septic nm0504: yeah so they open them up so they get septic spit in the wound sm0541: and they pump them full of drugs during the operation and then afterwards nm0504: absolutely simple as that anaesthetic agents post-op what do they give them ss: painkillers nm0504: pain relief non-steroidals okay prerenal failure local ischaemia what else do they give them post-operatively for the fever sm0542: antibiotics nm0504: speak up sm0542: antibiotics nm0504: antibiotics which one which group sm0542: nm0504: gentamicin aminoglycosides notorious nephrotoxins so this is a lethal combination being dry being septic and having drugs now of course these are connected you know you may become septic post-operatively which makes you dry via a volume depletion cause in other words septic shock and sepsis leads to drugs so you're septic you become dry and you get drugs for the whole thing so these thi-, three things are connected so whenever i go to the surgical wards and see somebody with er acute renal failure that is always my presumption that the patient has been given what i call the surgical cocktail so the treatment is actually quite simple you give them fluids you take away the drugs and you make them bi-, bit less septic er and it may involve writing up more drugs but at least you're going to cross off the drugs they were on and put them on on less nephrotoxic drugs and they almost always get better okay so the clinical features of acute renal failure are largely predictable er i don't particularly want to go through them in a-, in any great detail because it's all too easy er but basically the clinical features are those of the fluids and solutes that you can't get rid of and the only two important clinical features i've listed there in bold which are fluid overload and hyperkalaemia and in fact these are the two important clinical features of acute renal failure and they're also the two reasons we normally do dialysis so you need to know those two for for those two reasons so if you forget everything else i say this morning just remember the two important and life-threatening complications of acute renal failure are fluid overload and hyperkalaemia and they are also the two absolute reasons or indications for dialysis all others are relative the other clinical features again you don't get rid of hydrogen ions metabolic acidosis Kussmaul's breathing er any anybody seen anybody with Kussmaul's breathing nope okay er in the books it's described as air hunger absolute rubbish but you know people say they then go [gasp] [sigh] they sort of sigh a bit they don't c-, it's severe short of breath and it's the differential diagnosis for somebody who's short of breath they're not hungry at all they're just dying hungry er Kussmaul's breathing yes the phosphate goes up the calcium goes down the haemoglobin goes down these are more features of chronic renal failure they do happen to an extent in acute renal failure er there are other causes of anaemia in acute renal failure if the haemoglobin is inappropriately low or going down quickly what might be lady there what might be the cause of acute renal failure if the haemoglobin is inappropriately low six six and falling rapidly with a creatinine of four-hundred it's inappropriately low and falling rapidly so it's sf0543: nm0504: six today four tomorrow sf0543: decreased oxygen nm0504: mm yeah due to sf0543: less oxygen bound to the haemoglobin nm0504: possibly anybody else sm0544: E-P-O nm0504: sorry sm0544: E-P-O lack of E-P-O nm0504: no no that's what i want you wanted you not to say 'cause that's the cause of anaemia in chronic renal failure it's only part of the cause of anaemia in acute renal bleeding so there are only two ways of having a rapidly falling haemoglobin bleeding and how can you get rid of blood cells from your body quickly if you don't bleed sm0545: nm0504: speak up sm0545: through the urine nm0504: er yes eventually yeah but before that ss: nm0504: speak up sm0546: haemoglobin haemoglobin nm0504: mm yeah haemolysis is the answer there are only two common causes of rapid you know haemoglobin's ten six two not nine eight-point-eight seven-point- nine rapidly falling haemoglobin there must be some way of getting blood out of the body quickly and they're the only two ways and so if somebody's haemoglobin is inappropriately low in acute renal failure just a-, as if they're inappropriately low and falling in the disease they're the two diagnoses we we think of okay uraemia uraemia now there's a word er Greek derivation probably means urine in the blood er have we got much further than the Greeks probably not actually i i don't think they understood uraemia i'm not sure all that we understand it all i can say is there was an ill defined syndrome in which you don't feel very well doctor er in which toxins build up in the blood there are tens of thousands perhaps hundreds of thousands there is a modern concept of middle molecules big toxic things of middle size that are er damaging or make you unwell nobody actually knows find out do a PhD probably already done one find out what the middle middle molecules are find out why people are unwell in both acute and chronic f-, you know we still don't know er medicine is not all over i'm sure i'm not the only lecturer who's stood in the front and said it's all sorted out i mean i think if if er if we if medicine was a clock and we were attempting to sort it out we're probably about five past the hour at the moment er we're nowhere near having sorted it out we're no-, 'cause we're nowhere near understanding the pathophysiology of most disease processes and acute renal failure's just an example cancer atheroma whatever you like er okay there is an ill defined syndrome which i've listed the effects of there er it's ill defined therefore i'm not going to try to define it the history well of course the history is important history is always important er kidney doctors are famous for not taking histories we're numbers doctors we like numbers we say hello to the patient look at the numbers decide whether he dies and go home go to the pub whatever we we we er registrar hangs around puts a line in the patient gets better or dies we get biscuits [laughter] but we we er the history is important and i shouldn't knock the history probably the most important thing that you can do in the history is find out what drugs they're on drugs drugs drugs okay because it's both the cause of acute renal failure in up to thirty per cent of patients er and it may also er give you clues about the underlying aetiology so if they're on a drug for hypertension perhaps an ACE inhibitor it may be they've got renovascular disease and they should have had the ACE inhibitor so the drugs are important in a variety of for a variety of reasons how do you how do you take lady at the black there with your thermos er [laughter] you you er is that coffee in there or sf0547: no it's water nm0504: water sf0547: it's not a thermos nm0504: er it er how do you how do you take a drug history then from the patient just a bit of role play sf0547: you ask to see their chart nm0504: bit of role play sf0547: [sigh] [laughter] if they're in hospital you can ask to see their chart rather than ask them nm0504: yeah i know but they're not they haven't got they're in the medical admissions ask me some questions sf0547: what drugs you're on nm0504: about what what drugs i'm on sf0547: what tablets do you take every day nm0504: i'm not telling you [laughter] come on sm0548: what are you taking nm0504: oh you better go than that [laughter] that's just one you've got to ask the question again sf0547: er can you as-, could you tell me what drugs you're taking nm0504: [sigh] g i gave them to the other doctor earlier didn't you write them down sf0547: do you have them them with you any of them nm0504: well they're in my bag they're do you want me to get it sf0547: yeah nm0504: all right sf0547: could i have a look at them nm0504: okay [laughter] so er i don't know i don't know which one i'm i i don't know which one i'm i'm taking but you know and i've got a big i've got a list here from my G-P and and i've got a load here and i i i don't know you know i j- , i i don't know i mean every doctor i see puts me on a different tablet sf0547: er nm0504: come on Gestapo [laughter] sf0547: which of those did you take this morning nm0504: very good all right we're getting there very good d-, do you really want to know all right okay i took this er well i don't know what it's called it's blue [laughter] do you know the do you know the blue one doctor [laughter] sf0547: [laughter] do you have the bottle so i can see the label nm0504: all right here is here it is here it is okay so you're writing it down okay so very good okay i'll we'll stop there but but it's very hard to take a drug history er often the patient's got no idea the drug list is wrong and you actually have to get the actual tablets actually in front of you compare it to the drug list unless you've got a particularly articulate patient and you trust the drug list you know and find out what they're actually taking by taking a precise and careful drug history you may save the patient's life by being a bit of a pain in the arse er and it may involve sending the wife home to get the tablets from the bathroom by er you know ringing the G-P in the morning you've got to be a detective in terms of drug history and it's very very important not just in in in renal disease people er in my opinion very er too readily give up on a drug history of the patient and oh well i don't know you know or and they don't pay you find there aren't any pink tablets you know er they you know they the don't give up take the history put the screws on get the light out Gestapo treatment is what's needed for er a drug history i missed some other er important features of the history there there is one modern myth er about er kidney failure which i've listed for you there which is high blood pressure causes kidney failure kidney failure causes high blood pressure it's a nice little mantra and if you'll repeat that you've read it in your book absolute rubbish absolute lie it's like most verbal oral myths it's it's a m-, oral myth because somebody told somebody who told somebody who told namex who told me to tell you and that's how it's come into being there is no evidence that high blood pressure causes kidney failure so if you forget everything else i say just remember that kidney failure causes high blood pressure both in acute and chronic kidney failure but bog standard mild to moderate essential hypertension no other risk factors does not cause kidney failure and never accept it as a diagnosis er accelerated hypertension can cause acute renal failure but accelerated hypertension is quite rare and it's only a major problem in blacks and Asians whites can get it but blacks and Asians in particular d-, do you all know what i mean by accelerated hypertension anybody not know some shakes in the back accelerated hypertension i'm not going to talk about it in detail today a well defined syndrome it's been written about for a couple of hundred years combination of extremely high blood pressure systolic over two-hundred for example being unwell hepatic encephalopathy hepatic retinopathy acute renal failure dissecting aneurysms a constellation of all the problems er which fits into the dimensions of accelerated or sometimes use of the malignant hypertension that does cause acute renal failure but never take hypertension as a cause of acute renal failure otherwise okay er i've put a little phrase there funny diseases in the family er when you take a family history it's not enough to say what did your mum die of what did your dad die of oh sorry not sorry about that er what did your mum die of yeah oh your dad's still alive yeah sorry about that assuming your both your parents were dead er er be careful when you know you have a patient who's about fifty their parents might be alive or even sixty they might be alive so don't or go straight into what's what did your mother die of just be careful to say er is your mother well or you can start off with you know er do you still have your parents something a bit softer than what did they die of d-, don't assume everybody's dead [laughter] er er funny diseases in the family er important in kidney disease er there may be a family history of organ-specific autoimmune disease their auntie's got diabetes their cousin's got thyroid disease and these all er increase the possibility of of autoimmune disease so we're talking about glomerulonephritis vasculitis extremely rare examination what is a rena-, a student asked me couple of days ago that's why i put this section in when i was preparing this at two o'clock last night don't think look when we become consultant lecturers we don't do things at last-minute-dot-com we do er we're no more organized than you are we're just a bit older have a bit less hair er [laughter] when i was doing this at two o'clock last night er er i remembered a medical student asked me a couple of days what is a renal examination i thought that's a good question now i don't know what a renal e-, i mean there's never a a renal chapter in a book is there there's cardiovascular respiratory G-I there's no renal examination i think what a renal examination is is a good cardiovascular because that tells you about fluid state a good G-I 'cause that tells you about the kidneys the liver plus the bladder which you always forget to feel plus listening for bruits particularly femoral particularly epigastric that's where you hear renal bruits in the epigastrium other things cause epigastric bruits aneurysms a load of other things but renal bruits also occur there and the very important thing the finger up the bottom [laughter] the finger must go up the bottom every time you see a patient [laughter] with acute renal failure er and in a woman should go er into the vagina as well er unless there is a good reason not to okay that's a gross generalization there's never really too many in a hospital only a hundred-and-thirty a bit dry going to have a finger up the bottom no [laughter] but if the renal failure is unexplained and you have reason to think they may have obstructive nephropathy remember the common cause of obstructive nephropathy in men is prostate in women is pelvic cancer pelvic cancer till otherwise proven and if you don't want to do those things fine but the-, then the onus i-, on you is to get somebody else to do it so my advice to you is as soon as you get on the surgical ward start putting your fingers up people's bottoms just get used to it you know [laughter] all doctors have to be able to do it and er and you're no different and just get over that mental barrier er and maybe the only clinical signs if you don't do it you're doing a patient it's like [cough] not examining you know you're actually not helping them very much because you don't want to do it 'cause you don't like [cough] er in terms of anything else to examine not really it's a complete examination a renal examina-, but s-, but er s-, specifying those particular areas right er investigations i'm not going to go into in any great detail i've listed a few questions for you there just remember the big three the creatinine what do you think the other two big ones are the big three there's always a big three key investigation of somebody with acute or chronic renal failure creatinine sm0550: urea nm0504: no anybody else speak up have a guess sm0551: calcium nm0504: no sm0552: sm0553: G-F-R nm0504: no sf0554: calcium sm0555: calcium in urine nm0504: sorry sm0555: calcium in your urine nm0504: dipstick sm0555: okay nm0504: okay and important radiological tests calculated guess sm0556: X-ray nm0504: no sf0557: ultrasound sm0558: ultrasound nm0504: ultrasound okay X-rays can kill you [sniff] ultrasounds don't er so these are the big three tests and anybody with acute renal failure needs a complete history and examination and a knowledge of the result of these big three tests within twelve hours or you haven't done your job right if the renal failure is unexplained if it's explained on clinical grounds you don't have to do everything all the time you don't have to do an anchor er antineutrophil cytoplasmic antibody on everybody with a creatinine of hundred-and-thirty in medical admissions who's got appendicitis but if the renal failure's unexplained you have to do it er and they are the big three tests potassium yes is all right big four but potassium in my mind slips in with the creatinine you know if you're doing a creatinine you're checking the potassium er yes you want to know the potassium because that's what kills people and that's the important thing on which you decide whether to dialyse people or not er but it doesn't tell you about kidney function and that's what the creatinine does what's what's the creatinine for the liver gentleman in in red there what's happening to the liver sm0559: no idea nm0504: anybody do you want to he's the liver man is he what's the creatinine for the liver [laughter] he's pointing to you so sm0560: cheers er i don't know nm0504: how do you measure liver function sm0561: L-F-T sm0562: L-F-T sm0563: L-F-T nm0504: i'm glad you said that no er I-N-R the I-N-R is the creatinine for the liver that's what they measure on liver transplants four times a day there is to be honest there isn't a creatinine for the liver there isn't as good a way of measuring liver function i mean okay they're bright yellow liver in the three-hundred in trouble with the liver but there there isn't really a good creatinine they need they need a creatinine to to m-, as a m-, good marker of liver function but when the liver actually fails the I-N-R goes up and it goes up rapidly it goes up exponentially so as soon as your I-N-R starts going up you're in big trouble er okay so they're the big three tests er are they easy to get yes all very easy the dipstick you can do the creatinine you can do the ultrasound you can organize it's a Friday evening you want to go home the patient's unwell you don't know whether to ring a radiologist they might shout at you who cares if they shout at you they don't have to like you you're not in this game to be liked er get that ultrasound by hook or by crook er within twelve hours in somebody with unexplained renal failure lie give your right arm firstborn whatever you like just get it er why do people become radiologists why do people become radiologists technicians why radiologists sf0564: they can't be a doctor nm0504: 'cause they can't be a doctor [laughter] what a dreadful thing to say you evil cynical woman yes er er there then er yeah no they don't want to be doctors [laughter] they don't want to take complete responsibility they're they're er they're very important they're vital but they don't want to take complete twenty-four hour it's like G-Ps i mean i was appalled yesterday at the crap i heard on the radio about G-Ps not wanting to take responsibility why do they become doctors that's what medicine's about taking re-, biscuits [laughter] taking responsibility and er i almost rang up a few of my mates who are G-Ps and gave them some of my mind [laughter] but er i knew that would have no effect 'cause they they hate doing on call er if you don't like doing on call then don't be a doctor you know get out of the kitchen and er you know go and do something else go back and do microbiology at Liverpool or you know just don't be a doctor [laughter] if you don't like doing on call or or you're not willing to do on call that's my opinion harsh i know er okay so radiologists yeah they they they're nine to five people they're not you know they're nine to five Monday to Friday people actually i i'm maligning the namex radiologists ours ours are quite good they're actually quite easy to get scans but they'll always say oh can't i do it in the morning no you can't do it in the morning [laughter] one night i think i got four consultants in the hospital after midnight absolutely hated me in the morning i was completely wrong as well on on my diagnosis [laughter] er and there was a lot of lot of mumbling and swearing un-, under the breath going on about me that that night but er you know sometimes i get consultants in the hospital after midnight and i'm right and and then that's that's okay so if you're on call you're paid to be on call and you come in if you're asked it doesn't stand up in court er not coming in you can come in and moan you can come in and swear you can come in and malign er my parentage [laughter] you can say what you like but you have to come in it does not stand up in court saying oh well i gave some advice on the phone and yes Dr namex asked me to come in but i didn't think it was important and anyway i was watching er y-, you know and oh oh it's one minute past midnight doesn't stand up in court if you're on call you're asked to come in you come in there is no there's no middle there's no grey area you come in er it's completely indefensible one night actually a slight aside er i i was a locum locum renal S- H-O in Portsmouth and i was on without a registrar it was a it was a D-G-H type renal unit do you know what i mean by a D-G-H district general hospital sm0565: district general hospital nm0504: it's a non-teaching hospital and i was on with the professor who was er a well known er er extrovert a bit cravat-positive and [laughter] [laughter] er he i i'd never ever put a er er a peritoneal dialysis catheter into anybody and a patient came in very sick with acute renal failure over the full monty and i rang him and he said oh namex er just pop a catheter in [laughter] and i said but i've never done one sir actually we did use to call the bosses sir in the bad old days and er he said oh get the nurses to talk talk you through it [laughter] and i say well i i really don't think that's a good idea sir you know i think i think you'd better come in and supervise he said oh all right all right then and he just sort of had another port and came in [laughter] pissed out of his head er and i remember er to this day it was way past midnight and er i remember pushing him out of the way 'cause you could smell the port [laughter] you didn't have to see it and he talked me through it and the patient survived er he's [laugh] now retired the great Professor namex er in Portsmouth er [laugh] forgot what i'm talking about now anyway er [laughter] distinguishing er prerenal and established renal failure er or distinguishing er what some people call a tu-, tubular nec-, necrosis why what is this syndrome of established renal failure stroke A-T-N stroke A-T-D what is it let's anyone like to have a stab at it and i want a full-blown teleological evolutionary argument involving life the universe and ev-, and everything in the last ten minutes of this talk who's going to have a go come on doesn't matter if you get it wrong lady in red there no not brave enough no i wouldn't be either [laughter] er there is a phenomenon there is a syndrome of established renal failure stroke A-T-D stroke A-T-N which does exist and there may be an evolutionary basis to it er what happens if you go into kidney failure whatever cause usually prerenal failure for a while you don't reverse the prerenal failure and the kidneys shut up shop so why might there be an evolutionary advantage to the kidney shutting up shop lady in red you can answer that why might it be a good idea for you to be able to stop your nodes working your kidneys working your heart working obviously it's not a good idea to stop your heart working [laughter] but why might it be a good idea to stop your kidneys from working sf0566: it might be er taking away from else kind of nm0504: er lady on your on your right in the cream sf0567: to give your kidneys a bit of a rest nm0504: [laughter] yeah give them a rest very good give the kidneys a rest okay and and when er you're cornered you're in the cave you've been gored by a sabre- toothed tiger you're bleeding to death it's about to move in for the kill you're hiding behind that rock you're entering prerenal failure it may be a good idea to hang low for a while and for your kidneys to turn themselves off and that's exactly what established renal failure is an A-T-N A-T-D the kidneys have an ability to turn themselves off ten to fourteen days on average twelve- point-seven completely meaningless number y-, patient has asked you how long am i going be in kidney failure for i say twelve-point-seven days sir and i don't really no i usually say a week or two er the kidneys have an ability to turn themselves off we don't understand it there may be an advantage to it or there may be a an advantage to it once in other words it's now maladaptation to the modern environment and therefore evolution eventually in a couple of hundred years' time or a thousand years' time will take it out of the out of out of the human being and perhaps all mammals er there are some clear advantages in being able to turn your kidneys off when i say turn them off they really go into a sort of recycled phase so the blood goes down the tube it meets the sieve and says no way Jose and comes back again so you don't you may make some urine you don't make much urine and and usually oliguria is a feature of established renal failure but not always well it's it's a feature initially er but the kidneys send the blood back if you like and you become oliguric if you stay in oliguric acute renal failure and you keep drinking what's going to happen lady in the grey there sf0568: you're taking in the volume you're not getting rid of it so nm0504: yeah so what's going to happen to you clinically sf0568: you go into volume overload nm0504: yeah you can volume overload exactly er so there is a phase in this cycle where you go from dry to in the middle to wet and what we try to do in nephrology is to spot this transition point and hopefully stop them becoming wet but if they do become wet we get rid of it with dialysis or diuretics or whatever and that is simply what established renal failure A-T-N A-T-D is and why the kidneys turn off and why they start up u-, up again we don't know what are what are the stimuli find it out become famous er it's a very very interesting phenomenon the the the concept of established renal failure distinguishing it from prerenal is extremely difficult and i've listed there or a table i just took it out of a book it's in all your books you can measure the urinary osmolarity and the blood osmolarity and all it's all rubbish we don't do that er urinary sodium if you're going to pick a urinary test and there may be a question about this in one of your exams so it's the type of table you do need to to know er the urinary sodium is relatively useful i cannot think the last time i measured the urinary sodium why does a urinary sodium er go up in established renal failure well in prerenal failure the kidney's still trying to work and if you're still trying to reabsorb sodium and so the sodium levels in the urine stay down as soon as they start going up it means you have established renal failure it's all rubbish you know it's er and it's all messed up by a patient always on diuretics which increase er sodium losses anyway er it's almost impossible to interpret a urinary sodium er i visited er a unit in in New York once drop that in the conversation [laughter] and er and they start at six- thirty i mean their lectures start at seven i mean my God if you ask a British medical student to appear at seven why i sincerely hope you wouldn't turn up [laughter] and i remember sitting through this like terrible lecture on urinary osmolarity and sodium at seven o'clock in the morning i i thought this this is this is just hell [laughter] and the only thing that kept me going was that knowledge you had pizza at eight [laughter] doughnuts at nine [laughter] eat all day long [laughter] with and also on on on the I-T-U trolley i'll never forget this they had cans for your Coke [laughter] and everybody arrived with your Coke and your Diet Coke Sprite Diet Sprite and put them in the trolley that was the only bit i liked about it er [laughter] okay treatment er i i know the second half of this talk is meant to be about treatment and er partly because we've only got five minutes to go and and partly er i don't think it's nearly as important as what i've talked about so far i'm not going to go into it in any massive detail other than to say the key decision is the D decision in other words do they need dialysis or don't they and that's a decision that i make on a daily basis and it's not that complicated er the books will list hundreds of indications for dialysis there are only two remember i said ear-, earlier on in the lecture there are only two important clinical features hyperkalaemia and fluid overload i and the only indications or absolute indications for dialysis are hyperkalaemia unresponsive to medical management and fluid overload unresponsive to medical management yeah i've listed a few others there two-A i've written down as acidosis so having said that sometimes we do dialyse people for rather obscure reasons particularly on an I-T-U if on an I-T-U situation somebody's got a creatinine of two-hundred a urine output of forty mls a minute they're going into renal failure but they don't really need dialysis but we know tomorrow we may want to give them a lot of fluid for some reason or we may want to give them an angiogram which is nephrotoxic or tomorrow we may want to give them T-P-N or N-G-P we may dialyse people for rather odd reasons but but most of the time they are the only two absolute reasons for dialysis i don't think it's necessary that you er go into how we dialyse in any great detail er just it's much more important you understand the physiology and the pathophysiology and the indications for dialysis the technicalities you'll learn later you put a tube in the neck you attach them to a whirly it isn't much more complicated than that er finally finally er who should be managing people with renal failure i've said that twenty thirty per cent of people coming into hospital have a raised creatinine and there must be between fifty and a hundred people coming to the namex every day so a lot of them will have a raised creatinine can they all be referred to the renal team please no i hope not that's one of the points of this lecture that you're going to be managing people where when the cause of renal failure is obvious and when you can reverse it easily it's when it starts to get tricky you need to call the cavalry and fortunately er in namex and namex we have a reasonable cavalry i'm one of six nephrologists and there's one that's on every day of the year including Christmas Day including New Year's Day and er if you're having problems call there's no point in tr-, being a hero you get no medals for being a hero in medicine just because you can manage a case of Wegener's granulomatosis on your own as a house officer out in namex it doesn't mean you should and i think if you have anybody with any major body system failure and you can't reverse it quickly you can't identify the cause quickly you should be seeking help and if you're in a hospital without a renal unit such as namex Nuneaton et cetera you need to be ringing the namex and asking for advice from a renal registrar or renal consultant and that's true of of a-, any major body system failure okay that's it questions not too many anec-, anecdotes and only one bollocks sorry nf0569: can i just say anybody here who hasn't signed the register can you do so i don't know whether they are either they must be somewhere nm0504: what happens er by the way what happens if you if you don't appear if you don't sign the register nf0569: sf0570: nm0504: namex can fail you nf0569: last year nm0504: did you fail any last year nf0569: just to let you know it was very close last year there were about four people who nearly failed the urinary nm0504: on attendance nf0569: on attendance yeah nm0504: excellent [laughter] okay any any questions on on acute renal failure nf0569: whether you agree with it or not is irrelevant it's