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BRITISH BROADCASTING CORPORATION
RADIO SCIENCE UNIT
CASE NOTES
Programme no. 4 - Anaesthesia
RADIO 4
TUESDAY 27/09/05 2100-2130
PRESENTER:
MARK PORTER
REPORTER: TRISHA MACNAIR
CONTRIBUTORS:
DAVID SUTTON
PETER NIGHTINGALE
PRODUCER:
ERIKA WRIGHT
NOT CHECKED AS BROADCAST
PORTER
Hello and welcome to the operating theatres of the Wessex Nuffield Hospital in Southampton for a behind the scenes look at the world of anaesthesia.
Anaesthetists are the unsung heroes of the medical world - suffice to say that if I collapsed and could choose a colleague to save me I would plump for an anaesthetist every time.
It's half past eight in the morning here and James is the first of five patients on this morning's routine orthopaedic list. He's hoping that his knee operation will help him get off the bench, and back onto the pitch.
JAMES
I played football, I played the rest of the game and woke up the next morning and it was just swollen, couldn't move it, it was sort of locked.
PORTER
So you're hoping this will get you back to your football?
JAMES
Yeah, it needs to.
SUTTON
Okay a small scratch coming up on the back of your hand. It's great he's so relaxed when somebody's about to stick a needle in.
PORTER
Dr David Sutton has been working in anaesthetics for over 25 years. He is a consultant anaesthetist at the hospital, and the man who will be putting James to sleep - as well as looking after him while the surgeon operates on his knee, and making sure that he is awake and comfortable before being taken back to the ward. But first the general anaesthetic.
SUTTON
We'll do this in two stages. The first stage is just like a little starter, just to get you going and soften you up a bit. So we'll just put that in there, it won't send you right to sleep, just relax you a little bit.
PORTER
So you've got your drugs drawn up ready here for the first patient. Can you talk me through them?
SUTTON
Well we've got a mixture of drugs there because there's no one drug that does everything that we need. What we normally start with is one of these in the small syringe and this is a sedative drug here, this is fentanyl, which is a painkiller and then this is midazolam, which is a sedative and we give these just to kind of start the process off. So just get the patient relaxed, get the blood pressure down, everything's calm and they get a little bit sleepy, the eyelids start to droop. And when we see that then we actually move on to the anaesthetic proper, the induction, and that's the big syringe with the white drug in here and this is Propofol.
PORTER
Looks like milk.
SUTTON
It does yes, well in fact it's a fantastic drug because it has very good characteristics, you go to sleep smoothly, you wake up smoothly and you don't feel sick with it, in fact you feel hungry and you feel very clear headed very quickly, so it's a fantastic drug.
PORTER
And that will keep the patient asleep for how long?
SUTTON
That'll keep them a sleep for about two or three minutes.
PORTER
Do we know how propofol's working, what it's actually doing to the brain?
SUTTON
Well now that's a question, if you can answer that you'll win the Nobel Prize because nobody knows how anaesthetics work. We know - we roughly know it works at the cell membrane - so it blocks transmission of your brain activity - but we don't know how that happens.
Okay we'll squirt the anaesthetic in and we'll have you asleep in about 10-20 seconds, okay, so what I want you to do is just let yourself relax, just let this wash over you. Let your eyes close and just feel yourself drift away.
When you're anaesthetised you don't blink and if you watch here you see the eye often stays partly open like that and what we don't want is somebody to - when I'm adjusting the tube scratch his eye or for the drapes across, the paper towels, to rub on his eye because that would cause an abrasion, so we just gently hold the eye shut with a little piece of tape and that stops damage to the eyes. Also the eyes would dry out because if his eyes are open he's not blinking and the air in here is very dry.
PORTER
So the Propofol will put them off to sleep ...
SUTTON
Yes.
PORTER
Then we connect them up to the anaesthetic machine and if you walk over here, this is a typical anaesthetic machine - it's a very familiar metal trolley with lots of gauges and pipes that people would have seen on lots of television programmes.
SUTTON
Yeah. And these haven't changed essentially in design since the '20s, but they've been obviously vastly improved but the principle's still the same, in that we're giving a mixture of gases - oxygen to keep the patient alive obviously and nitrous oxide is an old fashioned gas - that was the first ever anaesthetic, it was used to entertain the masses at travelling fairs in America.
PORTER
Laughing gas.
SUTTON
Laughing gas exactly. And that's useful because it dilutes the oxygen because we don't want to give a hundred percent and also it's got a powerful painkiller and it's the equivalent really to a shot of morphine.
PORTER
Now this is something new, I haven't seen one of these before ...
SUTTON
Yes.
PORTER
Laryngeal airway I think.
SUTTON
It's called an LMA - a Laryngeal mask airway. What it is, is a kind of internal mask that sits just inside the mouth and it stops the tongue falling back and blocking off the airway. So instead of us having to put a little airway in and hold a mask on, we can put this in and then we can stand back and watch the patient and write our notes. So it's really revolutionised anaesthetics.
PORTER
So, once James has fallen asleep after the injection - the so called induction agent - David inserted an airway into James's throat and connected it to a mix of oxygen and nitrous oxide, all bubbled through a vaporiser full of volatile anaesthetic (essentially a modern version of chloroform or ether).
James will breath for himself throughout the operation, and David can adjust how deeply he is anaesthetised by varying the amount of vapour he inhales. Too much and he'll go too deep - too little and he'll wake up.
The next obstacle is to move James from the anaesthetic room into the adjacent operating theatre - a move that takes less than 30 seconds but which means he has to be disconnected from one anaesthetic machine, and reconnected to another waiting in the theatre. But the switch is a practised routine for the theatre team, and James is soon on the operating table and being prepped for the op.
SUTTON
After we induce the anaesthetic often the breathing either stops or is reduced temporarily for a minute or two, so we just help them with their breathing until they start on their own. The drugs we use tend to suppress breathing, the painkillers and the anaesthetic, but that's good because it stops them coughing and gets them settled. What we try and avoid is noise in the anaesthetic room because hearing is the last sense to go and so if you have a loud noise it can sort of jerk them and the blood pressure shoots up and the pulse shoots up, so we try and keep it nice and relaxed and calm.
PORTER
Is that induction phase, when you're putting people asleep, one of the trickiest phases, is that when things can really go wrong?
SUTTON
Yes it has been likened to flying, the old clich茅 - that's take off and landing that are the difficult bits and with anaesthetic it's the induction and the recovery are the potential times when you might have a problem.
PORTER
Patients are often very worried about having an anaesthetic, in fact they worry more about the anaesthetic than they often do the surgery.
SUTTON
Yes, I've found that they're worried about five things really. They're worried that they won't go sleep, they're worried that they won't wake up or they'll die during the anaesthetic or they're worried that they will wake up but it'll be halfway through. And then they're concerned about pain and nausea afterwards. One of the big revolutions that we've had in anaesthetics is the monitoring and I started anaesthetics in 1980 and we had no monitoring at all, so we could keep a finger on the pulse, we could see if the patient's lips were blue or pink but with this we think that we've halved the cardiac arrest rate, I mean it's so low that it's difficult to measure.
PORTER
We're looking at a screen here now which has got four or five different parameters.
SUTTON
This top one is ECG and each one of those is one heart beat and that tells me that his heart is beating, it tells me it's a normal heart beat, it's a normal rate and it tells me he's not getting angina.
PORTER
But if the surgeon was to stick the knife in and that suddenly shot up that's a pretty good clue.
SUTTON
Well it is but of course you feel pain when you're unconscious because when you're asleep a night you roll over and you move around, although you're unconscious, and if your wife digs you in the ribs because you're snoring then you're going to react to that, although you might not wake up. And anaesthetics are similar, so in a light plain of anaesthetics you would respond to the pain, even though he was asleep. But we aim to give them enough painkillers that we don't see a lot of disturbance here because what keeps anaesthetics safe in older patients with heart disease you want that pulse rate to stay low, stay normal, you want the blood pressure to stay normal, you want the oxygen levels normal, you want everything normal, so we adjust the anaesthetic to keep those normal levels of everything and that makes you safe.
PORTER
And before we had that machine the only way you could tell that they weren't getting enough oxygen or one of the ways you could tell was looking at their colour.
SUTTON
You were looking totally blue and you were looking at the lips but it's a change that happens late, so you don't notice and if you're anaemic it might not happen at all. So you're picking up a change maybe 5-10 minutes after it's started whereas with this I can pick this up the second it starts. As you get experienced you have in the kind of back of your brain this awareness, so I can hear this beep and the tone of that beep, which you can hear there, is related to the oxygen level, if that tone starts to drop that means the oxygen levels are dropping, so even though I might be talking to you I've still kind of got this ear switched on to that tone.
PORTER
So what else have you got?
SUTTON
This is probably the nearest thing, this is monitoring the actual level of the anaesthetic agent. What it does is sample the gas that's going in and out of the patient, so I can see that figure there - 1.6 - says that it's roughly 1.6 more anaesthetic than he needs. And we can tell that he's still quite asleep because his pupils are very small and that's another sign and as you get arousal, stimulation your pupils dilate. With all these things together I'm 100% sure this guy's asleep. What makes me really sure is that he's not sitting up and saying I'm awake, which he could do, he could do, if he woke up he would wake up and tell me. So there's no way that this chap could be aware.
PORTER
Does it matter how often you have anaesthetics, I mean if you were in for - if you have a nasty accident and you've got sort of repeat surgery, is there a cumulative effect?
SUTTON
No, I can anaesthetise this chap every hour for the next week or so without any real problem. But the interesting thing is this chap won't know whether it's five minutes or five hours because when you're asleep you kind of wake up with a vague idea that time has passed but because we kind of stopped his brain waves he'll wake up not knowing whether it's five hours, five minutes or five days, in fact he may not even realise he's been asleep because of the way we anaesthetised him.
Have you finished off there Wilf?
WILF
Yes, just finished off now.
SUTTON
We've come to the end now, so what we're going to do is wind down the anaesthetic and most of the drugs that we've used we'll allow to wear off, so we'll just wait a few more minutes and then we'll turn off the vapour, turn up the oxygen, wash the anaesthetic out and then he'll wake up.
James, James, all finished.
You often see anaesthetists walking around supporting the airway and feeling for the breath on the palm of the hand, it's very sensitive, if you blow on the palm of your hand that's the best way to see if somebody's breathing.
James, that's it, it's all finished, open wide, spit that out. We'll take you to recovery.
NURSE
Hello, are you alright there? You've had your operation, you're just waking up okay.
SUTTON
This is a really high care area, a lot of people think recovery's the kind of quiet backwater in nursing but it's not, this is really an intensive care unit.
PORTER
But it allows you the anaesthetist to go on to the next patient knowing that your patient's being taken...
SUTTON
Yeah, but I wouldn't start until he's awake, as you can see he's now awake, he's breathing, he's talking, he's stable, so I can start the next case.
PORTER
Time for David to prepare the next patient on the list.
Meanwhile Trish Macnair has been finding out that there is a lot more to anaesthesia than putting patients to sleep. Indeed many of the patients on a modern intensive care unit are awake and only lightly sedated - even if, as many are, they are so ill they can't breathe properly for themselves and require artificial ventilation. In the past that would have invariably meant paralysing the patients with a curare type drug, and knocking them out - often for days, weeks, and sometimes even months - so they couldn't move, cough, or fight the ventilator. But recent advances mean that patients on an ITU today are much less likely to be heavily sedated.
NURSE
I'm just fiddling with your left armpit, just popping a little temperature probe in there, alright? Okay. Do you feel comfortable or do you want us to change your position? Just nod - do you want to change your position? Okay, well I'll get some help and we'll pop the pillows in the other side, so you'll go on your side for a bit and get a bit of pressure off your bottom. Alright? Okay.
NIGHTINGALE
This lady here has had pneumonia and has got blood poisoning. She is very sick, she's requiring 90% oxygen to breathe and yet if we walk up to her and ask her to open her eyes she would do because she's on quite a high dose of a painkilling drug but only on a very low dose of a drug which will make her sleepy.
MACNAIR
Here on the Intensive Care Unit at the Wythenshawe Hospital in South Manchester, consultant Dr Peter Nightingale is taking me round to see some of his patients.
Some have multiple injuries after road traffic accidents, while others have problems such as life threatening infections or severe asthma. They need intensive support but these days few have to be deeply sedated, because modern ventilators breathe along with the patient's own efforts, this means they don't have to be paralysed.
Even so, most will be given medicines that also have a sedative effect. This can be very useful, helping to calm the patient in a very stressful environment. But sedation can cause problems too.
NIGHTINGALE
One of the side effects of excessively sedating people is that their immune system is suppressed, they don't absorb nutrients from their bowels well and their muscles waste. And therefore excessive sedation is as bad as under-sedating people. If you under-sedate them their heart rate may go high and their blood pressure may go very high and this can be dangerous for the heart. So we have to titrate between the two extremes.
MACNAIR
Titrating - or carefully adjusting the amount of drugs to control the level of sedation - aims to keep the patient comfortable, but at minimal risk from side effects. Drugs which provide sedation are usually given through a drip into the veins. They are very short acting, and don't last long in the body, so the levels of sedation can be quickly regulated. During painful procedures, like changing a wound dressing, the nurse simply turns up the drip.
NIGHTINGALE
Titrating sedation is an art and the nurses are the best at it because they're there all the time and they're doing it. You'll see on the intensive care unit that even deeply sedated patients the nurses will talk to them, they're looking for the flicker of an eyelid or any signs that the patient is responding. And if they're not doing anything particularly stimulating to the patient they'll lighten up the amount of sedative agent that's being given.
MACNAIR
Staff nurse Kelly Macbeth talks to her patients all the time, whether wide awake or apparently deeply unconscious. Not only does it help her judge the patient's level of sedation but it's a natural interaction which she hopes will help to calm any anxiety.
MACBETH
Even though Sue, who we were just talking to, is quite lightly sedated, so you get a response, people just tend to unconsciously speak to people even if they're fully sedated. Actually sometimes even if patients - this might sound strange - but if a patient's sort of recently passed away it's hard to get out of it, so even though you might be rolling someone who isn't - who's just passed away, you still talk to them.
MACNAIR
A careful record is kept of the patient's level of sedation, to help judge how much medication is needed and where problems might be developing.
NIGHTINGALE
This is the simple sedation score we use, this was developed at the University College, London and as you can see we make a note of whether the patient's asleep or paralysed, you'll see very few Ps for paralysed, we hope you'll see lots of As for natural sleep. But the score goes from minus 3 to plus 3, we never want to see somebody who's agitated and restless, which is a plus 3 and similarly we don't want to see a patient who's minus 3, which is unrouseable, because that means they've had an excessive amount of sedative agent.
MACNAIR
The skill of sedating a patient is not just to use purely sedative drugs but to use a combination of treatments, including painkillers, tranquillisers and other drugs which reduce unpleasant memories.
NIGHTINGALE
The fascinating thing about talking to patients after they've been discharged from the intensive care unit is how little they remember. Even when you think they're apparently fully conscious and able to comprehend what's happening when they leave they often have very poor memory of what went on.
SAM
It's everybody that passes by say oh you're looking better and I in fact feel worse.
MACNAIR
What about all the sort of technology and equipment has that been unnerving?
SAM
It frightens me, I just close me eyes.
MACNAIR
Sam has spent more than three weeks on the ICU, with serious complications including organ failure after emergency surgery. But despite a long and traumatic stay, he remembers nothing of his painful battle for life.
SAM
Apparently I had a ruptured ulcer, is that correct doctor?
DOCTOR
That's correct.
SAM
And I didn't do anything about it, well I knew when it happened at the time but then the next thing is I woke up in hospital, I had no idea, no idea at all. It's that sort of psychological twist.
MACNAIR
Although many patients in the ICU appear to be snoozing, sedation isn't sleep. And that means patients may be missing out on the restorative properties that the human body gets from real sleep.
NIGHTINGALE
When you're asleep after about one and half hours of falling asleep you go into a thing called REM sleep, which is rapid eye movement sleep, and the patient is then in a phase when they're starting to heal their body tissues and it is necessary to have REM sleep for sleep to be effective. The drugs that we use on the unit don't actually put you into REM sleep, you can occasionally fall asleep after you've had your sedation but they are not having true natural sleep when we sedate them with some of the drugs that we give. But we do other things - we keep the unit quiet if we can, we darken the lights at night, we may put headphones on the patients, so they are protected from the noisy environment and we do hope that they sleep naturally but we know from studies that this unfortunately rarely occurs.
PORTER
Consultant anaesthetist Peter Nightingale talking to Trisha Macnair on the Intensive Care Unit at Wythenshawe Hospital.
Back in Southampton Dr David Sutton is about to put another patient under general anaesthetic for an operation on her knee.
What makes you decide to offer a patient a regional or local anaesthetic versus a full general anaesthetic, where they're knocked out?
SUTTON
Well there are sort of a number of considerations, one is what the patient wants, I mean we don't impose a technique on a patient anymore, what we hope to do is outline the options to a patient and then help them come to a decision which is right for them. But having said that there are some techniques where you can't use local anaesthetics, if I was doing say major head or neck surgery I can't really use a local technique because it's just technically impossible. But if you're having something on the leg then that lends itself to local anaesthetic. Or you can put a spinal or an epidural low down in the back, these are the same as women may elect to have in labour, that effectively numbs you from the waste down.
PORTER
Is it a safety issue - would you offer a regional local because you're concerned about giving that person a general?
SUTTON
Well no it's not quite that simple, if you look at the research there's no real evidence that one anaesthetic technique is safer than another, the risks are very, very low with either technique. But there are some patients where you'd elect to use a local technique or keep them awake and that might be somebody with bad chest disease or some sorts of heart disease where it's best to keep them awake, keep them breathing, keep everything stable.
PORTER
And what happens if the patient changes their mind, if you're in the middle of a big procedure - I'm thinking of something like a hip replacement, now you and I know that's a pretty gory procedure, people knocking and drilling in your own hip, some people can take it, some people can't - and if they change their mind halfway through the op and say doctor, I don't like this, what can you do then?
SUTTON
We can then move on to a general anaesthetic or you can just deepen the sedation, so we would run an infusion of that first milky anaesthetic agent, that I showed you earlier on, and we can run that at a very low level, just enough to kind of put you into a very light sleep, so you'd be rousable, I could shake you and wake you up and talk to you but you'd drift off. So if they then get fed up with it, you can deepen that or you can move on to a full general anaesthetic. But I think what we need to make sure the patient's know is that you're not locked in to some horrible traumatic procedure if you just don't like it.
PORTER
What do you think about public perception of the role of the anaesthetist? I remember when I was doing anaesthetics that actually I was speaking to some friends at a party or some people I met at a party who were actually surprised that I was a doctor.
SUTTON
About a third of the population don't realise we are doctors. Because we've got this intimate knowledge of physiology and pharmacology - of how the body works and how drugs work - and we have a set of life saving skills - managing the airway, managing the heart and the circulation - that means that we can kind of move out into lots of different areas. So if you look around you find that anaesthetists are running in - most intensive care units are run by anaesthetists, most chronic or all chronic pain units are run by anaesthetists and also we're very much involved in trauma, so a lot of the roadside trauma and the helicopter trauma with HEMS that you see, a lot of that is done by anaesthetists. Because I think HEMS have shown that the single most life saving benefit that they offer is delivery of anaesthetic skills to the roadside and they can be delivered by A&E doctors or other doctors who are trained but anaesthetists ...
PORTER
This is where people get confused though isn't it, when you say anaesthetic skills it's not necessarily anaesthetising them, it's actually life support, pain control, correcting blood loss, treating major shock and trauma.
SUTTON
Yes and all that goes on during an anaesthetic for major surgery as well, which is why we're so good at it because we're using those skills every day, and so we can then apply them to trauma and keep the skills current. And really we're clinical pharmaco-physiologists in that we know how the body works in intimate detail and we know how the drugs that we use affect the body. So I mean most doctors prescribe a drug and they see the patient some point later, maybe six weeks later and see whether it's had an effect, if I give a drug now I can see the effect instantly. In fact in heart surgery where you've got the heart in front of you, you can give a drug and see the heart change in front of your eyes. So that needs a really detailed knowledge of what's going on.
PORTER
It is all a bit of a plumber's nightmare this end, isn't it, you've got the patient here with a tube going into his throat, connected up to these pipes, now these are clear plastic pipes, they're not the classic thick black ...
SUTTON
The old black rubber.
PORTER
What happened to the old black rubber?
SUTTON
The old black rubber - well it was black because it had carbon in it and the reason it had carbon in was so it conducted static electricity because prior to these modern anaesthetic agents the ether and the other agents were explosive and so if you had a spark you could literally have an explosion in the anaesthetic circuit and there are historical descriptions of explosions in theatres and anaesthetic rooms and fires and you can imagine having the patient explode is not really a desirable outcome of an anaesthetic.
PORTER
I notice that despite all of this high tech monitoring, state of the art stuff, that you're still recording the measurements of the blood pressure and everything by hand on a conventional anaesthetic form.
SUTTON
It's a record that helps me keep track of what's happening but it's a very important medical legal record, so I mean I do medical legal expert witness work and all I've got to go on is what the anaesthetist has written down and other notes. The other problem is I'm looking after the patient primarily, I'm not primarily here to write down what I'm doing, so it's a bit like saying if you skid your car and crash do you want me to take notes while it's happening - it's just never going to work is it. So a lot of our notes are kind of retrospective. If something's happening and I've got to do something to the patient I then write it down, I might be 10 minutes later.
PORTER
A lot of patients are worried about feeling sick after the anaesthetic, is that much less with the modern agents that we're using, is that a hangover from the old days?
SUTTON
Yes. If you take morphine, for instance, morphine is still the drug derived from opium poppies and it comes in all the side effects of the opioid drugs, so you get a degree of nausea, of sickness, you get some hallucinations or dysphoria, you can get itching and you can't - there is no drug, no powerful painkiller that doesn't have those side effects, if you can invent that you'll be very rich.
PORTER
And what can you, as the anaesthetist, do to minimise that?
SUTTON
We've got a whole range of drugs now, we've got some more recent drugs which are very good, very effective, very powerful anti-sickness drugs, so we can not guarantee you won't feel sick but we can design an anaesthetic that's less likely to make you sick and then we can treat the sickness if you are sick. It's not really something to worry about anymore I don't think.
PORTER
What developments are in the pipeline that excite you in the field of anaesthesia?
SUTTON
The holy grail is to actually measure how deeply the patient is asleep because I can tell you they've got enough anaesthetic but I can't actually tell you how deeply they are asleep. The thing up here that says this chap is 100% asleep ...
PORTER
Not too light ...
SUTTON
Not too light, not too deep, just spot on.
You can hear the alarms going off and these are going off because we've turned the anaesthetic off.
PORTER
So the operation's over now, the surgeon's finished, just finishing off, but I mean it's just basically a matter of turning off the gases.
SUTTON
Yeah and what we've done is we've turned off the nitrous oxide and the vapour which is keeping him asleep and you can see that the level here has dropped down pretty much to zero. So he's just starting to wake up. We don't want him to wake up with his eyes taped closed, that might not be a very pleasant experience, so we'll just start to dismantle all the taping and take the monitoring off as he wakes. And we'll leave the key monitors on right until he's wide awake.
Leslie - Les, all done, all finished. Les, a bit of oxygen okay, just going to take you through to recovery now.
ENDS
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