Adverse reaction to methohexitone and gallamine

Abstract

Summary A c'ase is presented in which a patient dei)eloped an acute unaphylactoid reaction after receiving methohexitone and gallamine for the induction o f anaesthesia. The problem o f eliciting the responsible agent is di.scusscd, with comnients on the method o f rreatment and prewntatiw measures. Key wordsA llergy Anaesthetics, Intrarrenous; methohexitone. Nmromuscular relaxants; gallamine.Sodium methohexitone (Brietal) and gallamine triethiodide (Flaxedil) are both drugs which have been used in anaesthetic practice for many years, and in spite of the vast number of administrations of each drug the number of adverse reactions reported is very small. A case is presented in which a patient developed an anaphylactoid reaction after receiving these drugs. Case historyA fit 43-year-old woman was admitted for laparoscopic sterilisation. She had had two previous operations: a reduction of a fractured radius when she was 8 years old, and an appendicectomy at 18 years of age. Her past medical history included an anxiety state and six normal pregnancies. She was taking no medication before admission, and there was no history of allergies. Her pre-operative haemoglobin was 1 1 g/dl.A prernedication of papaveretum 10 mg and hyoscine 0.3 mg was given 1 hour before induction. and she was calm and relaxed on arrival in the anaesthetic room. Anaesthesia was induced with sodium methohexitone 120 mg and gallamine 120 mg, followed by inflation of the lungs with oxygen, tracheal intubation, and elevation of the legs in Lloyd Davies stirrups. Suddenly she developed erythema and goose pimples on the skin of both legs, her pulse rate rose from 80 to 140 beats/minute, and rapidly became impalpable. The blood pressure was unrecordable using an oscillotonometer, and an electrocardiogram showed complete heart block with a ventricular rate of 54 beats/minute. The patient's lungs were being ventilated by hand with IOO", oxygen through a Bain system. Ventilation became progressively more difficult, and auscultation revealed very little air entry. Peripheral cyanosis then developed.Intravenous infusions were set up in both arms, Adverse reaction to methohexitone and gallamine 41 and 2.5 litres of fluid (0.9% saline 1 litre, plasma 0.4 litre, and Dextran-70 1 litre) were given, together with chlorpheniramine 20 mg, methylprednisolone one gram, and atropine 1.2 mg. Cardiac output was maintained by external cardiac massage for 20 minutes. Ventilation of the lungs improved with this therapy, but there was no alteration in heart rate. Metaraminol4mg was given slowly, but with no effect. This was followed with 10 ml of adrenaline 1 : 10,000 intravenously, again with no effect. An isoprenaline infusion of 4 pg/ml was commenced, the heart rate increased to 140 beats/minute, and a systolic blood pressure of 100 mmHg was achieved. The peripheral circulation slowly returned to normal, and on cessation of the isoprenaline infusion the pulse rate slowed down to 80 beats/minute, and the systolic blood pressure was maintained at 100 mmHg. It was now 45 m...