Gouri Rao Passi

From the Department of Pediatrics, Choithram Hospital and Research Center, Indore, India.
Reprint requests: Dr. Gouri Rao Passi, 139, Indrapuri, Indore, 452 001 (MP), India.

Today the serious student of medicine is faced with large volumes of bewildering information. The brain handles confusion by reducing choices and possibilities. Simplistic rules about how to investigate and treat a patient appeal tremendously. But breakthroughs in medicine occur when one has gone beyond self imposed boundaries and rigid rules. Learning to handle information is becoming more important than information itself.

In day to day practice, every clinician is faced occasionally by a diagnostic problem which defies solution. What does one do then? Before tackling the esoteric let us first understand the banal. How does an average doctor reach a diagnosis in actual practice. Sackett et al. have described four strategies of clinical diagnosis(1). What we first learn in medical college is the strategy of exhaustion. This technique has two stages: first a thorough collection of all medical data of the patient (all of us would remember taking history of the past, family, birth, immunization, development, social). The next step is to sift through all the data to search for the diagnosis. This technique is appropriate for the novice and is abandoned with experience. The next strategy is pattern recognition. The sight of a boy with hypertrophied calf muscles, climbing on to himself as he gets up (Cowers sign) would signify Duchene muscular dystrophy for most pediatricians, without a word of history. Experienced clinicians would diagnose renal failure or hypothyroidism as soon as such a patient walks into their consulting rooms. The third technique is the multiple branching technique or the algorithm. Here all possible alternatives to a particular complaint are noted. The response to each alternative determines the next inquiry to be carried out and so on till the solution is reached. This is useful when the diagnostic procedure is being carried out by someone not well versed in that field. For example, health workers who need clear guidelines regarding what is to be done. The fourth strategy is the hypothetico-deductive model where, with the initial discussion of the problem, possible diagnosis are short listed and further questioning and examination is directed towards collecting supportive evidence for possible diagnoses. This is the technique commonly employed by most clinicians and correct hypotheses have been reached in an average of 6 minutes(2).

But how does one tackle the difficult diagnostic puzzle. One can either try harder or smarter. Harder implies spending more time (and possibly money) in collecting more information. The smarter way is to employ better techniques of thinking. One possible way is the use of lateral thinking, a term coined by Edward de Bono(3). This differs from traditional logical and sequential thinking in making different use of information and approaching a problem from different angles. The various techniques are simple and easily mastered.

The Technique of Reversal

This involves doing the opposite of what would be the logical solution. In the old fable the clever crow wanted to drink water from the partially filled jug. Instead of employing techniques to suck the water out, the crow put pebbles into the jug. In pediatrics the logically appealing therapy for hyperactive children would be sedatives. However, surprisingly they respond to stimulants. Vaccines also work on the same principle. To prevent an organism from infecting the person, one actually introduces it oneself (though in an attenuated form). To reduce the problem of drug addiction, a novel technique is used. The drug is legally given to drug abusers. In these well known methadone maintenance programs, opiate addicts are given methadone, a long acting opiate with almost all the properties of heroin. Though it does not cure opiate addiction it 'reduces crime due to drug trafficking and improves functioning within the family and job.

The early ventilators were massive bulky objects, based on the physiological principle of creating negative pressure around the lung causing it to expand. The opposite technique of pushing in air instead, is the basis of the sleek modem positive pressure ventilators. Another paradoxical phenomenon that sociologists have encountered is that to reduce the population, one must first improve survival. Improving life expectancy is automatically associated with a decrease in birth rates.

Challenging Labels

Often mind blocks are due to the fact that the problem has been prejudged and given a label. The etiology of peptic ulcer disease had been drummed firmly into our minds as an excess of acid secretion in the stomach. It's very name suggests it. But one inquisitive mind happened to wonder whether an infectious agent could be the cause. Thus began the saga of Helicobacter pylori and it's role in the pathogenesis of ulcer disease. This hurdle of pregiven labels are extremely common in day to day practice. Instead of just making an observation, the first person to see a patient (commonly the most junior) often gives it a label. Sometimes it is wrong and the error continues to be accepted by the succeeding physicians and multiplies. The "patient with hematemesis" may later turn out to have had hemoptysis, sometimes after an endoscopy. The increasingly educated patient today may sometimes be the unwitting culprit. One child was admitted with the history of "measles" followed by generalized weakness. He turned out to have dermatomyositis and the "measles" had been actually the rash of dermatomyositis. The labeling of the rash as measles diverts our thinking into channels of post measles complications. One of my most vivid memories is of a patient with bilateral "hilar lymphadenopathy" who Went for open thoracotomy and biopsy and turned out to have bilateral pulmonary aneurysms. Another child being treated for "periodontitis" by the dentist and under investigation for "petechiae" by the hematologist reached our Pediatric Neurology Clinic for evaluation of her "paraplegia". We diagnosed scurvy.

Search for Alternatives

Traditional education trains us to systematically sift data till a promising solution is reached. In the lateral approach one keeps on generating hypothesis or solutions even after the apparently correct answer is reached. Copper sulphate granules work very well for umbilical granulomas. But it was the person who thought "what about something else?" who realized that common salt works as well. One always panics on encountering a patient in shock with all collapsed veins and no IV access. But the intraosseous route is valuable and safe in emergencies (4). The use of colostrum for neonatal conjunctivitis is another novel idea. Liquid ventilation where oxygenated fluorocarbons are poured in and out of the lungs to facilitate oxygen ex- change, breathes of a man who has broken free of the tired habits of conventional thinking. Esophageal foreign bodies don't necessarily need endoscopic removal. A Foley's catheter can be introduced into the esophagus and the baloon inflated beyond the object. Gently pulling out the Foley's catheter will drag the foreign body out. A useful exercise for any physician is to develop a "quota" system. This means always trying to generate a fixed number of differential diagnosis in every case, say four or five, even if the diagnosis is obvious. It keeps the mind sharp and comes in handy in a crisis.

Fractionation

Breaking a problem into parts is another simple technique. The art lies in knowing how to divide a problem. Children in Bangladesh were dying of cholera. The apparent solution was to eradicate the Vibrio cho/erae and stop the diarrhea. But if you broke the problem into loose stools and dehydration, correcting dehydration with ORS worked fine. In the child with diabetic ketoacidosis one separates each problem: hyperglycemia, dehydration, hypokalemia and acidosis. Each part when separately corrected, by IV insulin, IV fluids, potassium and bicarbonate replacement is integral to the treatment.

Exposure to Different Fields

Cross fertilization of ideas from different fields often yields unusual fruit. The combination of physics and medicine has exploded the field of imaging especially so in recent years. 'With the use of virtual reality, surgeons may soon be able to operate from a distance. Art and drama therapy are gaining importance in the management of developmentally retarded children. Several bright doctors today are opting for a masters in health administration. Applying modem management principles has vastly improved the efficiency of our hospitals. Other emerging fields include space medicine, telemedicine and sports medicine. The possibilities are endless.

Finally, lateral thinking cannot replace traditional logical thinking but complements it. It helps when faced with a difficult situation, but should be used even if there is no apparent problem. To end with a note of caution, though our thoughts must be unfettered and free, while dealing with patients, our actions must be tempered with wisdom.
 

1. Sackett DL, Haynes RB, Guyatt GH, Tugwell P. Clinical Epidemiology. A Basic Science for Clinical Medicine, 2nd edn. Boston, Brown and Company, 1991; pp 3-18.

2. Barrows HS, Norman GR, Neufeld VR, Freightner JW. The clinical reasoning of randomly selected physicians in general practice. Clin Invest Med 1982; 5: 49-54.

3. De Bono E. Lateral Thinking. A Textbook of Creativity. London, Penguin Books, 1970.

4. Mc Namara RM, Spivey WH, Sussman C. Pediatric resuscitation without an intravenous line. Am J Emerg Med 1986; 4: 31-33.