John Kenneth Galbraith, the Canadian economist, invented the phrase “the conventional wisdom” (CW), pseudofacts that everyone knew to be true, were hardly ever questioned but which, when challenged were often not evidence based. Medical textbooks are full of such CWs.
Differentiating between sharp and blunt appreciation? Simple. The CW is to ask the patient “Is this sharp or blunt?” when administering a sharp or blunt stimulus. Er, no. Differentiation can be quite difficult. Have you tried it on your own feet? A more useful question is to ask, when alternating a sharp and blunt stimulus, “Is there any difference between these?”
The CW when testing for cerebellar intention tremor in the arms is to use the finger to nose test. Er, no. Cerebellar intention tremors get worse as the target is approached and this may cause an affected patient to jab their face. Ask the patient to touch your variably positioned fingertip with their fingertip.
The CW for testing nominal dysphasia is to show the patient a common object and ask them to name it. Er, no. This is insulting if they can and sometimes distressing if they can't. Far better to pretend to be testing vision “I want to test your vision. What is this?”
Testing for defective short term memory is patronising if normal and often distressing for the patient if abnormal. The CW is to give a sequence of numbers to remember or ask about current events. It is better to ask, “How long have you been here?” or pretend to be asking about appetite “What did you have for breakfast this morning?—in hospital practice this should be known.
When examining the abdomen the CW is that the patient should be lying flat, with their hands by their side, breathing through their open mouth, and letting their abdomen wall relax. Lying flat? Er, no. If the abdominal muscles are to be relaxed to facilitate palpation it makes sense for the hips to be flexed and this can be achieved by having the knees drawn up with the ankles near the buttocks, or for the patient's chest and head to be raised slightly by pillows, or the bed or examination couch head to be raised slightly. Incidentally when did you last sit on an examination couch? The conventional couches are unjollyly uncomfortable, do not assist relaxation and, if the head end is raised by 45 degrees, patients slide down the incline especially when a paper undersheet is being used.
The CW is that increase in the jugular venous pressure (JVP) is a good indication of a failing right heart. Er, no, not at 9 am in hospitals it isn't. The CW is that the only way to confirm or monitor JVPs is to insert a central venous line. Er, no. Certainly not in my case. The veins on the back of my hand are easily visible and when my outstretched arm is slowly elevated and, providing there is no constriction proximally, my hand veins collapse at the level of my JVP—thus constituting a “Poor Man's CVP”.
You might think that I have made a good case that CWs are sometimes wrong but it is opaquely obvious that the CW is that CWs are always wrong (including this one).
Footnotes
* I use this made up word because it is useful and has five consonants in sequence. For some reason I think this important.
† Diuretics are invariably given at about 7 am. Look for raised JVPs later in the day.