QUANTITATIVE ASSESSMENT OF RESIDUAL ANTIDEPOLARIZING BLOCK (PART II)

An attempt to estimate residual neuromuscular blockade afterthe administration of anti-depolarizing relaxants to anaesthetizedpatients is described. A train of four supra-maximal nerve stimuliwas applied to the ulnar nerve and the twitch response (mechanicalor electrical) was recorded. The frequency of the train usedwas 2–2.4 Hz with an interval of 10 seconds between thetrains. Clinical recovery from the relaxant was assessed bythe ability to lift the head. The ratio of the height of thefourth response of the train to that of the first (ratio (c))gave a good indication of the degree of residual neuromuscularblock as indicated by this simple clinical test. As ratio (c)increased muscle power improved. Obvious muscle weakness wasassociated with values of ratio (c) of less than 0.6.