Home > 書籍 > 5 – Dealing with uncertainty about the effects of treatments > Dramatic treatment effects: rare and readily recognizable

Dramatic treatment effects: rare and readily recognizable

In this sub-section:

Introduction

Only rarely will the evidence be so clear-cut that there is no room for doubt about whether a treatment works [2]. In such cases the treatment effect is often dramatic and immediate.

Take the heart rhythm disorder known as ventricular fibrillation, where muscle contraction in the ventricles (lower chambers) of the heart becomes wildly uncoordinated. This is a medical emergency – death can occur in minutes. The technique of ‘zapping’ the heart with a direct electrical current from a defibrillator applied to the chest is used to restore the heart’s normal rhythm; when successful, the effect is virtually instantaneous.

Other dramatic effects include drainage of pus to relieve pain from abscesses, blood transfusion for shock caused by severe haemorrhage, and insulin (a hormone produced by the pancreas) for diabetes. Up to the 1920s, patients with diabetes had short lives and suffered immensely, wasting away with uncontrollably high blood sugar levels. Very quickly, the initial results of animal tests led to the use of insulin in patients, with outstanding success – their response was near miraculous at the time.

Another example from that era was the use of liver – later shown to be a source of vitamin B12 – for patients with pernicious anaemia. In this then fatal type of anaemia, the numbers of red blood cells gradually fall to disastrously low levels, leaving patients with a ghostly pallor and profound weakness. When these patients were given liver extract they recovered rapidly, and vitamin B12 is now prescribed routinely for this form of anaemia.

Some examples from the beginning of this century highlight similarly dramatic results.

NextModerate treatments effects: usual and not so obvious