[Myasthenia gravis as an anesthesia risk]

Myasthenics must be considered as surgical risk patients. It is imperative to know the exact pathophysiology of the disease pattern with its three types of crisis including their treatment in order to perform safe anaesthesia and to reduce the rate of perioperative complications. In the preoperative phase we must consider a few specific angles besides the routine manipulations: Treatment with cholinesterase inhibitors as practised in myasthenics is continued unchanged or with only slightly reduced dosage up to the day of the operation. If necessary, oral administration may be changed to intramuscular or intravenous application. Premedication is carried out as far as possible without any drugs contraindicated in myasthenics. The patient may get regional or full anaesthesia, the latter always via intubation. We prefer inhalation anaesthetics because they are easily monitored. Neuroleptanalgesia, however, is also possible. One must accept the somewhat higher risk of postoperative respiratory insufficiency since in most cases subsequent artificial respiration must be performed anyway. Relaxation is effected, if at all necessary, via a non-depolarising muscle relaxant in low dosage (one-half to one-tenth of normal dosage). Measurement and monitoring of neuromuscular transmission via the nerve stimulator is mandatory. Succinylcholine is used only in case of vital indication (half of the normal dose). After surgery the patient is transferred to the intensive care ward in intubated position, extubation being performed only after spontaneous breathing has been safely assured. In postoperative analgetic treatment the opiate antagonist pentazocine (Fortral) showed the best results as far as our experience goes. With careful monitoring, however, it is also possible to employ other highly effective analgesics.(ABSTRACT TRUNCATED AT 250 WORDS)