Sunday, February 25, 2007

How to learn medicine

It can be difficult being a medical student. I remember having at least twice as many timetabled teaching sessions as my non-medic friends and there was a huge amount of stuff to learn. Sometimes I felt like I was using my brain purely to stuff textbooks into instead of to think with. The practicals were better although some of the physiology ones seemed to be mild forms of initiation ritual. We did a lot of carefully measured breathing and urinating in them.

I did a traditional style course, something the Angry Medic is battling through at the moment and wondering if one of the shiny new style integrated PBL based fashionable courses would have been a better choice. I can’t really say because I haven’t done one, but before the traditional style course gets chucked out like those Dallas style shoulderpads at the end of the 80s, I’d like to remember the good aspects of the course.

Most of the time there was only one textbook to consult. When I was learning anatomy I looked in the anatomy book. Simple. None of this trying to learn the anatomy, physiology, pharmacology, pathology and treatment of a heart attack all at once. It also meant we had anatomists teaching us anatomy, pharmacologists teaching us pharmacology etc unlike having a pathologist trying to teach you about all the medical aspects of a hernia. By the time we were let loose on patients we already knew where their organs were and how they worked and a bit about how their drugs worked, it might not seem much but it helps.

But the best bit was when it suddenly all made sense; sometime in third year the reason for learning everything I’d learnt before became clear. Maybe it was a long time to wait but so what. We were in a teaching session with one of the cardiologists, who took us to see a patient who had been admitted with chest pain a few days before. The cardiologist asked us what conditions could cause chest pain. Er…heart attack….er…..angina. We didn’t do too well until she told us to think of all the structures in the chest that the pain might have come from and now we were back to basic anatomy. It was suddenly much easier. It could be pain from the heart (MI, angina), oesophagus (oesophagitis, reflux), pericardium, pleura (pleuritis, pneumonia), ribs, chest wall muscles, nerves (shingles), costochondral junctions etc. Basic physiology told us why the patient might have gone into heart failure after a heart attack, and a bit of pathology and pharmacology explained the use of aspirin and nitrates. The knowledge was there in our heads and now it was time to do something with it.

The basic sciences are vital. I don’t know if they are covered as well in new integrated courses or sidelined in favour of communication skills. Surely part of being able to communicate with patients is having something useful and accurate to tell them about their illness, why it has happened, why it causes the problems they are having, what you are going to do about it and what is going to happen to them. Or maybe even why you don’t yet know what the problem is, what it might be and how you’re going to find out.

The best way of teaching medicine is still causing controversy and there are various discussions on doctorsnet (if you have access) about different courses and different medical schools. But if you walk down the street in the UK you’ll see some 80s fashions are coming back again. maybe medical courses just follow fashion too.

Saturday, February 24, 2007

Have you had the test?

When we hear about celebrities being ill or admitted to hospital we hear phrases like ‘undergoing tests’ and ‘tests showed that…’. ‘Tests’ are obviously very important and a lot hangs on the results. ‘Tests’ are safe and always right. Aren’t they?

We’ve all seen patients where the test gets it wrong; the normal x-ray in the patient with bone metastases or the dangerously high potassium level due to a dodgy blood sample in a normal patient. In these circumstances we know the limitations and problems with the test and can repeat the test, do a different test, or even ignore the result.

I’m sure that all medical students and junior doctors have had some rules about diagnostic tests drummed into them by their seniors:

If you don’t know why you’re doing a test you shouldn’t be doing it

If you don’t know what you’re going to do about the test result when you get it you shouldn’t be doing it

If the result of the test isn’t going to change or aid in the patient’s management you shouldn’t be doing it

Treat the patient not the result
(all tests can produce false positive or false negative results)

This avoids patients having unnecessary tests and unnecessary or wrong treatment based on incorrect results. Obviously unnecessary treatment could be risky with surgical complications or drug side effects but some tests carry their own risks, for example radiation exposure (x-rays, CT scans etc), bleeding (liver biopsy) or other injury (colonoscopy, diagnostic procedures under anaesthetic).

We try to take these problems with diagnostic tests into account but sometimes doctors as well as patients can become over reliant on them for diagnosis or reassurance (or medico-legal reasons). Many of the diagnostic tests we do have had their reliability studied in depth before they are recommended for everyday use because it’s important to understand how often and in what circumstances a test is likely to give a false result. Newer tests are still being studied and developed and we’re often cautious about them. The histopathologists out there will know about the latest immunohistochemical stains which show early promise at differentiating benign from malignant or being highly specific for a certain type of tumour. When more research is done they are often not quite as good as we initially thought, although they may still be useful.

In 2003 the RCPath produced some draft guidelines: Who can request a test? This document then seemed to vanish but over three years later it is finally being revised into a more definitive form. The draft version states:

the test must not only be ordered appropriately, but also… the result must go back to someone who can take appropriate action.’ (sounds just like what your consultant told you when you were a house officer).

On a related note they’ve also released this report: Evaluating and introducing new diagnostic tests: the need for a national strategy. This document talks about some of the things I’ve mentioned above about the reliability of tests and summarises the issues that must be looked at when introducing new tests, the first of which is:

Is the scientific evidence for the validity of the new test sufficiently robust?'

The report also goes on to state:

There is increasing pressure to introduce new tests precipitously, without rigorous evaluation of their true utility, when related to emotive topics (such as cancer) or when there are possible medicolegal threats.

It is difficult for staff to evaluate recently introduced tests objectively and consistently across the NHS; published evidence demonstrates that papers on the diagnostic accuracy of new tests are often of poor quality and to make a good decision is difficult.

The RCPath might be a bit late with these documents as increasing numbers of ‘diagnostic’ or ‘screening’ tests are being offered to anybody with the money to pay, as well as the time and stress resilience to cope with subsequent investigation of their incidentalomas.

Shinga has written about some of the allergy tests available and finds, via some dedicated literature searching, that they aren’t as reliable as some suggest. Despite the amount of work that should go into studying tests, Shinga has found that tests can be let loose on the public without being properly validated, and worrying they can be requested by anybody – regardless of the risks.

Saturday, February 17, 2007

Organs and autopsies

A while ago I talked about the latest Royal College of Pathologists Bulletin, and mentioned two things in that were particularly interesting. One was training and the second was coronial autopsies (page 13 if you can get hold of a copy). This article by Dr Peter Cowling, discusses the latest NCEPOD report (and its launch at the RCPath) which I’ve also talked about before.

One of the main points made both in the report and in the article is that the function of the coronial autopsy is not well defined. I think part of the problem is that as medics we see the autopsy as a medical procedure, whilst the majority of coroners are not medically qualified and to them is it the legal aspects that are important. At its most basic the legal function of a coronial autopsy is to exclude an unnatural cause of death and this (in combination with the new Human Tissue Act and coroners’ rules) leads to the situation where, as soon as a plausible cause of death is identified, the autopsy is stopped and no histology, toxicology or microbiology etc is usually done. This occurs in the jurisdiction of some (the minority I think), but luckily not all, coroners. No toxicology? Remember Harold Shipman? As a medical procedure this practice is unacceptable. The RCPath position as stated in the article is:

post-mortem examinations should be performed to the highest standards possible, to answer the needs of relatives and to serve the public health through improved national mortality statistics’

After reading a paper referenced by this article (Discrepancies between clinical and postmortem diagnoses in critically ill patients: an observational study. Full text available free) I would add ‘providing feedback to the clinicians treating the patient’ to these functions. Historically this was one of the main functions of the autopsy – in the past the autopsy room would have been full of doctors seeking to learn and improve their practice. Now it is almost deserted and this function has been sidelined. The rate of consented (non-coronial) autopsies has declined dramatically recently.

The paper above looks at patients dying in an intensive care unit. They reviewed 38 cases which is not a huge number but considering the low and declining number of autopsies is not surprising. 39% of the cases had a major diagnosis missed before death, although the missed diagnosis may not have had an impact on the patient’s survival.

I’m sure all of us trainee pathologists have heard consultants say that a third of death certificates are wrong, something also mentioned in the NCEPOD report, hardly a good thing for mortality statistics. If finding a plausible cause of death and then stopping the autopsy is also occurring then this is likely to reduce the accuracy of the cause of death in some autopsied cases. So falling autopsy rates and the poor standard of some autopsies is likely to have a negative impact on mortality statistics.

As for answering the needs of relatives, as the RCPath article says, we don’t know what the relatives or the public want from autopsies. Maybe they don’t care at all about autopsies, is this the reason for the results of the NCEPOD study sinking without trace in the media? I don’t think is entirely true; autopsies were never out of the news during the organ retention scandal. So what do the public think of autopsies now? Do they know why autopsies are important, what the uses of the autopsy are and the potential consequences of badly done autopsies? Do they understand how the Human Tissue Act and coroners’ attitudes to autopsy histology (partly in reaction to the organ retention scandal) make medical investigation of deaths difficult and the implications of this? I doubt it. A browse through the RCPath guidelines on autopsy practice shows why histology is so important as a component of the autopsy, including in relation to cardiac deaths, where the heart may need to be retained for specialist examination to assess any genetic problems that might affect other family members.

During the NCEPOD report launch, Professor Peter Furness talked about some of these problems and wondered if the next ‘organ retention scandal’ would be failure to retain important organs for further examination. In the past we had headlines like ‘Doctors stole my son’s heart’. Will we have ‘Doctors threw away my son’s heart’ in the future?

Saturday, February 10, 2007

Where are your kidneys?

This is first year anatomy stuff (for anybody who still does anatomy these days). What is the normal position of the kidneys in humans?

a) in the upper abdomen
b) in the lower abdomen below the waist
c) in the pelvis
d) in the sports department (that’s for any Two Ronnies fans out there)*

Many people think the answer is B, including it would seem, Dr Gillian McKeith (read about her PhD here). I saw this bit of news on the web saying that her book You Are What You Eat now tops the non-fiction chart of most borrowed books from UK libraries. Coincidentally a friend showed me this book the other day after a relative tried to convince her of the benefits of kidney massage. It’s on page 198 and encourages you to ‘treat yourself to a kidney rub…..find your kidneys by placing your hands on your back below the waist but above your bum’. If you’ve correctly answered the question above you’ll know this is utter drivel.

Now you’d expect me to know my anatomy. I’d be doing a ******* appalling autopsy if I didn’t know where to find the organs. You’d expect a surgeon to know their anatomy, in fact all doctors need to know their basic anatomy – even psychiatrists have patients with physical illnesses and need to know where organs are and how to examine them.

Yet anatomy teaching is being eroded in UK medical schools. There is a huge amount to learn as a medical student and anatomy cannot be taught in the kind of depth needed to be a surgeon, for example, more advanced anatomy can be learned during surgical training. But medicine is primarily about the structure and function of the human body and mind in health and disease. As doctors we need to understand that structure. We particularly need to understand it when so many other people are reading the kind of book that tells lies about our innards. Leonardo da Vinci knew where the kidneys were by 1508; how can such easily available facts be ignored?

*The answer, of course, is A. If your kidney was previously owned by somebody else it will be in position C. If your kidney is in position B it is abnormal and if it's in position D you're really in trouble.

Friday, February 02, 2007

Don’t die young

Some of my colleagues hate watching any medical programmes. The dramas are unrealistic and make them cross because of the number of inaccuracies and the documentaries are oversimplified and just stuff they already know. I enjoy some of the documentaries; they can be a bit like watching somebody else do some of the less taxing parts of my job while I relax with a cup of tea.

Last week’s episode of Don’t Die Young was just such a programme, presented by somebody who is actually medically qualified and with the experiments, though simplified and jazzed up for TV, illustrating real physiological principles. Dr Alice Roberts continues that great medical tradition of experimenting on yourself and even gets into the operating theatre to show ‘scenes of surgery which some viewers may find disturbing’ before 9pm.

What really interested me was the reaction of the smoker shown the lung cancer. Handling specimens like the one shown in the programme is a regular occurrence for me and it’s easy for us medics, nurses etc to forget that although we see cancer every day, the average member of the public encounters it relatively rarely.

Lung cancer (the yellow bit)

Lung cancer is still a fairly rare disease to the man or woman in the street; especially compared to the number of people they might know who smoke. For those of us in histopathology, cardiothoracic surgery, oncology and respiratory medicine it is far too common. For the lady in the programme, facing a real, grey and white lumpy tumour seemed to be a very powerful experience in her quest to stop smoking. I hope it had the same effect for others watching.

The lung picture is from the Pathology Education Instructional Resource.