Kaufmann in 1960 first recognised that patients with dystrophia myotonica had an unexpectedly high perioperative morbidity and mortality, caused primarily by cardiorespiratory complications) Patients with the disease frequently present for removal of cataracts, correction of anterior open bite and cholecystectomy.Anaesthesia is often complicated for several reasons. Preoperatively, as well as having specific problems with muscle wasting, weakness, myotonia and contractures, there is evidence of generalised involvement of the cardiac, respiratory, neurological and endocrine systems. 2These patients are especially sensitive to respiratory depressants 3 and often have an abnormal response to both the depolarizing and competitive neuromuscular blocking d~gs. 4In the immediate postoperative period anticholinesterases s and shivering 6 can initiate myotonic contractions.