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Summary The use of the new competitive muscle relaxant, atracurium, is described in five myasthenic patients presenting for thymectomy. With an initial dose of 0.1 mg/kg, that is approximately one-fifth of that normally used, and incremental doses of 0.02–0.04 mg/kg, satisfactory clinical conditions were achieved. Neuromuscular function was monitored throughout using the train-of-four mechanical twitch response, and residual neuromuscular blockade was reversed satisfactorily at the end of the procedure with neo-stigmine 5.0 mg. A marked increase in the magnitude of the first twitch of the train-of-four to greater than control levels, accompanied by pronounced fade. was found on reversal. In reduced dosage and with careful neuromuscular monitoring, atracurium is safe to use in the myasthenic patient.

Summary The anaesthetic management of a patient suffering from carcinoid syndrome and myasthenia gravis is described including the successful treatment of a carcinoid attack with intravenous aprotonin. The differences between myasthenia gravis and the myasthenic (Eaton-Lambert) syndrome are considered and the rationale for the choice of vecuronium as the muscle relaxant is discussed.

An investigation is described into the performance of two types of circle system used without a carbon dioxide absorber in both the laboratory and in the operating theatre with controlled ventilation. The newer system was found to be more efficient than the old but in both types of system the tidal volume was found to be very important, a large tidal volume resulted in increased efficiency. The possibility of predicting arterial blood carbon dioxide using this system is briefly discussed, and rules are suggested for the use of the system.

Postoperative analgesia both by drugs and regional techniques is reviewed. In the United Kingdom in the last 25 years or more there has been little advance on either front. Some marginal improvement in regard to drugs might be brought about by better education of both doctors and nurses and better patient contact. Extradural analgesia and intercostal block do not offer a complete solution, though a judicious increase in the use certainly of the former might be beneficial. The problem awaits a radical new approach.

SUMMARY It is frequently held that patients with severe respiratory disability should not be subjected to anaesthesia involving the use of relaxant drugs and positive pressure ventilation since it may be found impossible to provide adequate pulmonary ventilation after the relaxant has been given, or it may prove difficult to re-start spontaneous ventilation if the blood carbon dioxide tension has been reduced during anaesthesia. This paper describes a simple investigation into this problem based on data obtained from 12 ‘respiratory cripples.’ All had a maximum breathing capacity of less than 40 litres/min., and eight showed pre-operative respiratory acidosis. Premedication was with promethazine and atropine. Anaesthesia was induced with a small dose of thiopentone; muscular relaxation was produced by a large dose of tubocurarine, endotracheal intubation effected without the use of topical analgesics, and anaesthesia maintained with a mixture of nitrous oxide and oxygen, without die use of depressant drugs or volatile agents. A deliberate attempt was made to produce passive pulmonary hyperventilation by manual pressure on the reservoir bag, and in every case it was found possible to reduce the blood carbon dioxide tension to below the level found pre-operatively and usually to below 40 mm Hg. In no case was it found difficult to ventilate the patient's lungs, and there was no evidence of progressive hyper-inflation. At the end of the operation, atropine and neostigmine were administered; it was found that after stimulation of the pharynx and trachea spontaneous respiration appeared with the endotracheal tube still in situ and the patient still unconscious when the blood carbon dioxide tension was still lower than it had been pre-operatively. After extubation, which was accompanied by some breath-holding and coughing, a regular pattern was soon re-established at a blood carbon dioxide tension strikingly similar to that which had been found before anaesthesia. It is suggested that these results would not have been obtained had depressant drugs or volatile anaesthetic agents been used, and that the application of topical analgesic solutions to the larynx may likewise cause difficulty in re-starting spontaneous respiration. The use of full muscular relaxation would also seem to be of importance in preventing progressive hyperinflation and difficulty in maintaining adequate ventilation. ZUSAMMENFASSUNG Vielfach wird die Ansicht vertreten, dass bei Patienten mit schweren respiratorischen Storungen die Anaesthesie ohne Relaxans und ohne positive Druckbeatmung durchgefuhrt werden solle; einmal konne es schwierig sein, eine ausreichende Ventilation der Lungen nach Verabreichung des Relaxans zu erzielen, zum anderen konne die Wiederkehr der Spontanatmung schwierig zu erreichen sein, wenn die Kohlensaurespannung wahrend der Narkose verringert wurde. Diese Arbeit beschreibt eine einfache Untersuchung dieser Frage an Hand der Ergebnisse an 12 “respiratorischen Kriippeln” (Atemgrenzwert unter 40 1/min, in 8 Fallen praeoperative respiratorische Acidose). Die Praemedikation bestand aus Promethazin und Atropin; Narkoseeinleitung mit einer kleinen Dosis Thiopental, Relaxation mit einer hohen Dosis Tubocurarin, Intubation ohne Lokalanaesthesie; weitere Narkosefuhrung mit N2O-O2 ohne Zusatz anderer Inhalationsanaesthetika oder depressiv wirksamer Medikamente. Es wurde passive, manuelle Hyperventilation angestrebt; stets gelang es, die Kohlensaurespannung des Blutes unter praeoperative Werte zu senken, meist sogar unter 40 mm Hg. Ventilationsschwierigkeiten oder Zeichen allmahlicher Uberblahung traten nicht auf. Zu Operationsende Gabe von Atropin und Neostigmin. Bei Stimulation von Pharynx und Trachea trat-am bewussdosen Patienten bei noch liegender Tube-wieder Spontanatmung auf, obwohl der Kohlensauredruck noch unter den praeoperativen Werten lag. Nach Extubation (meist unter Husten und Atemanhalten) kam es bald zu einer regelmassigen Spontanatmung bei Werten der Kohlensaurespannung, die fast genau den praeoperativen Befunden entsprachen. Die Autoren sind der Ansicht, dass bei Gebrauch von Analgetika und Inhalationsanaesthetika diese Ergebnisse nicht zu erzielen gewesen waren, Gleiches gilt hinsichtlich ordicher Betaubung des Larynx. Fur die Verhutung allmahlicher uberblahung und von Schwierigkeiten der Beatmung scheint die komplette Relaxierung von grosser Bedeutung.