"50 Percent of what we teach our medical students will still be accepted as correct by the time they reach the end of their professional life; the trouble of course is that we and they don't know which 50 percent"
according to Dr Arthur C Kennedy FRCP, President of the British Medical Association.
The next 50 years could see a major overhaul of medical knowledge and practice. If a percentage as high as 50% of what is currently taught in medicine is indeed wrong, then a piecemeal approach to making changes just isn't going to be good enough. There will have to be a recognition of the ways in which the system of medicine can be improved.
An 'anaesthetic' used on infants undergoing surgery was later found to inhibit screaming, but not to inhibit the pain.
There is evidence that the MMR (Mumps measles and Rubella) vaccine may cause autism and irritable bowel syndrome, and that the vaccine for scarlet fever can cause severe brain damage.
My concern is not just that there are specific procedures wrong in current medicine yet to be identified and changed. My focus is on the possible 'system reasons' behind those 'mistakes'. How come the wrong techniques go unrecognised? If this is understood the same kind of knowledge could also lead to improvements in techniques which are already good and useful.
An understanding of the systematic reasons should have a greater potential for improving medicine - through many small changes - than singling out one medical procedure for review could.
Some procedures which are currently an accepted part of medicine may cause more harm than good. Surgical 'fusion' of spinal verterbrae may be one such medical procedure.
Fusion of vertebrae is used as a last resort in combatting chronic back pain. The theory as to why fusion should help is that incorrect movement of the vertebrae relative to each other causes pressure on a nerve. After fusion, these vertebrae will not move relative to each other, so they should not put pressure on the nerve.
However, fusing vertebrae in the lower back causes incorrect movement of other vertebrae higher up. Some people have thus had a series of vertebrae fused in successive operations to try to solve their problem. Others after one operation and a worsened situation have not gone back for more treatment.
The most difficult to treat patients who have found pain-killers unsatisfactory, for whom nothing else has worked, may stop coming back after the surgical treatment. This has the undesirable effect of making the treatment look better 'on the books' than it is.
Possibly the most dangerous area for systematic mistakes is in diagnostic procedures. The danger is that a diagnostic procedure may cause damage, and this may go unrecognised. Indeed, a faulty damage causing diagnostic procedure may be seen as being better than others alternatives, because it finds problems which other methods don't!
Diagnostics are a danger area for two reasons. Firstly there is a risk of there being no independent method of assessing whether the diagnostic procedure causes damage. Second the diagnostic inevitably 'interferes' with the very system it probes, and if the system is weakened, may cause further damage.
Are there other systematic problems in medicine?
Very probably there are. It seems to me that awareness of 'beneficial' bacteria is a relatively recent thing. Possibly there are also beneficial fungal infections and beneficial viruses? It seems plausible that as a minimum an innocuous strain might keep at bay a more serious one. Because 'good infections' are not the stock in trade of medical doctors, there is currently little or no assessment of the damaging effects of antibacterial, antifungal and anti viral agents other than in immediate effect on the patient. Whilst the beneficial effect (killing the specific disease agent) is looked at in micro, the harmful effects (obvious reactions to the drug) are only looked at in macro. This mismatch means that potentially easily collected information is being missed. Moreover, if a patient already ill with one infection comes down with another after being treated with a drug, this will systematically be put down to a weakened patient rather than to a problem with that drug. It's not the medicine itself that is the problem, it's our current way of assessing the benefits of medicines.
Another systematic area, and one that doctors take considerable care over, is the difference between symptomatic treatment and treatment of the underlying cause. When problems recur, doctors look hard for the underlying cause. However, even with the care being taken today it is still a danger area.
Skin conditions caused by allergy are a particularly challenging area. A GP may not be able to identify the allergen and therefore can only prescribe an anti-inflammatory. Treating the symptom by suppressing it is not entirely satisfactory. Anti-inflammatories interfere with the body's immune response. One of the known side effects of topically applied anti-inflammatories is that they can cause rashes to occur elsewhere. Another is that skin where they are applied can age more rapidly.
A problem is that until an allergen is tracked down a GP cannot say for sure that the skin condition is an allergic reaction. Instead a generalised 'underlying cause' like 'stress' may come to be seen as a complete explanation, and a specific hard to track down environmental factor left unidentified. Incomplete identification of the underlying cause together with a symptomatic treatment leads to a cessation of a search for the root cause.
To lessen reliance on treatment of symptoms we need to use additional levels of knowledge about root causes. In the area of skin problems caused by allergens this requires a greater systematisation of the knowledge we already have. This would help patterns to emerge.
Two potent and common allergens are from cats and from dust-mites.
The cat allergen is from cat saliva. Cats lick themselves, the saliva dries and then flakes off as a fine powder. Saliva contains compounds that break down food, both for digestion and so that the cat can tell whether it's fish or rabbit it is eating, for it is the break down products which give food taste. Cat saliva also helps cats to break down and remove dead surface skin when they groom themselves. Both these attributes contribute to making powder from cat saliva allergenic.
Dust-mites feed on flakes of skin and their digestive juices are designed to break down skin. Their excreta is therefore rich in compounds that break down skin.
Few doctors can be aware of the similar reason why dust mite excreta and cat 'dust' are so allergenic. Such knowledge should be taught in medical school for it would ultimately lead to a deeper understanding of hypersensitivity to different kinds of allergen. In turn this could make identification of what a patient was reacting to an easier task.