Tuesday, January 25, 2011 at 10:29AM
Source: The Sunday Times, Jan 16 2011
Doctors should rely on senses, experience and eschew costly, unnecessary tests
There have been many reports in recent years of doctors, in the United States especially, ordering too many tests. Many of these tests are unnecessary and contribute to the rising cost of health care. In addition, tests that depend on imaging by X-ray may expose patients to excessive amounts of radiation.
In the old days, there were fewer tests available and doctors had to think like detectives, using every clue to guide them to a diagnosis.
Most of the relevant information doctors need - up to 70 per cent or more, especially with neurological problems - comes from what the patient tells us. But it takes experience to pick up the relevant parts of the patient's story and not be misled by red herrings.
Doctors take down the history, a narration of how an illness started, evolved, what bothers the patient - for example, whether there is fever, cough, vomiting, headaches and so on.
The doctor might well ask other questions that may be relevant, depending on the hypothesis she has built up at that point, such as whether the patient smokes or consumes drugs - not only what may have been prescribed but also obtained illicitly.
While we are listening to what the patient tells us, we have to simultaneously think of various possible illnesses, and narrow down the possibilities to a few that seem most likely.
About 15 per cent of our information comes from examining the patient. This is usually done after taking down the history. Examinations often involve looking at, feeling, listening to - and sometimes, even smelling the patient.
An examination includes observing the patient's general condition. A doctor might look into various orifices, like the mouth, ears, and even anus and vagina when the clinical picture suggests the latter two sites may yield valuable information.
Next, we may palpate the patient, feeling and pressing on various parts of the patient's body, including the abdomen. This is often followed by auscultation with a stethoscope, to listen to the lungs, the gut and sometimes sounds that come from abnormal blood flow.
Finally, a neurological examination may be done if necessary. This is usually the most difficult part of the examination and many non-neurologists do not even bother to master the technique.
A good doctor can often arrive at a diagnosis through such examinations without conducting any test at all. Tests generally provide only 15 per cent of the information we need.
Of course, the precise percentage that comes from taking down a patient's history or examining him or from tests varies from disease to disease. Hence how we approach a patient depends on what we suspect.
It is also important to have an open mind, and gather as much experience as possible, because diseases do not always present themselves in the classical way. Also, once we have decided on a particular diagnosis, there is a tendency to forget that we may be wrong, and thus be ready to revise our diagnosis when some unusual feature turns up.
In 1982, I was training in paediatric neurology at Massachusetts General Hospital, better known as MGH (or 'Man's Greatest Hospital', as some have it). I was called down once to the hospital's emergency department because 'a baby had a fit'.
I asked the mother what happened. She said the baby had been perfectly well, suddenly gave a cry, vomited, then went limp and became unconscious.
Judging from her story, it did not seem to me that the baby had suffered a fit. Instead, it seemed to me that the baby had suddenly felt severe pain and fainted as a result. The vomiting suggested something had happened in the intestine.
In fact, any paediatrician who had been trained by Professor Wong Hock Boon, the father of paediatrics in Singapore, would have immediately blurted out 'intussuception'. It is a condition where one part of the small intestine telescopes into the next part and becomes stuck as a result.
I confirmed that it was indeed intussuception by carefully palpating the baby's abdomen. The abdomen was soft and the baby gave no hint that the palpation caused him pain.
In the right upper quadrant of the abdomen, I felt a lump. That was the part of the small intestine that had telescoped. If not urgently reduced - that is, unstuck - the gut would become gangrenous, the entire abdominal cavity would fill with bacteria, and the child would become seriously ill and probably die.
I told the crowd of paediatricians around me that the baby had intussuception. I suggested a barium enema be arranged as soon as possible. I was somewhat annoyed that none of them, not even the senior paediatrician heading the paediatric team in the emergency department, believed me.
Instead, they laughed and wondered why a neurologist was palpating the abdomen. After some argument, they agreed to do at least a plain X-ray, which might show up the intussuception.
It did. A barium enema was then arranged and a few hours later, the intussuception was reduced and the baby was perfectly well.
After that incident, I was no longer called 'that little China girl' by my American colleagues. Their impression of Singapore changed. They realised that doctors trained at the National University of Singapore (NUS) usually do not order unnecessary tests.
Rather, we use all our senses as well as accumulated experience, and perform only a few relevant tests. That combination can allow doctors to get to the root of their patients' troubles without conducting too many expensive tests.
I am proud of the NUS medical faculty. I am proud of the practical training it gave my generation of doctors.
Now, when I see young doctors emulating doctors in the US in ordering too many tests, I go out of my way to chastise them.
Adapted from an article on the ST, 16 Jan 2011