Massive pulmonary collapse during thoracotomy.

A 28-year-old housewife was admitted to hospital in congestive cardiac failure but treatment with digitalis resulted in rapid improvement. She had a past history of attacks of winter bronchitis and rheumatic fever at 12 years of age. Clinical examination suggested that the underlying lesion was stenosis of the mitral valve, and one month later the patient was referred to a thoracic surgeon for mitral valvotomy. Pre-operative investigation indicated a moderately severe degree of stenosis with enlargement of the left atrium, right ventricular hypertrophy and auricular fibrillation. There were no signs of cardiac failure, blood pressure was 120/80 mm Hg, pulse rate 67/min, haemoglobin 13.9 g per cent, and she weighed 63 kg. There was no clinical or radiological evidence of respiratory disease. Premedication consisted of papaveretum 10 mg and hyoscine 0.4 mg administered subcutaneously 1 hour before operation. After 3 minutes pre-oxygenation anaesthesia was induced with sodium thiopentone 350 mg, followed by tubocurarine 45 mg; endotracheal intubation was carried out with a 9.5 mm Magill cuffed oral endotracheal tube. Anaesthesia was maintained with 3 l./min of a 50 per cent mixture of nitrous oxide and oxygen using a Blease intermittent positive pressure ventilator and a to-and-fro Waters canister carbon dioxide absorption system. The lungs were easily inflated with pressures of 25-30 cm H tO recorded on the pressure manometer of the ventilator. The chest was opened after about 20 minutes and the left lung, which was expanding normally, was retracted by an assistant while the surgeon opened the pericardium and examined th: heart. Fifteen minutes later the surgeon requested that the lung be re-inflated before the valvotomy. When the lung retractor and protecting wet pack were removed the lung was completely collapsed around the hilum. It appsared to be quite airless, of rubbery consistency, and resembled a lobe of the liver. Vigorous manual ventilation with a high frish gas flow rate, which caused the ventilator manometer pressure to exceed the maximum on the scale (40 cm H,O), failed to re-expand the lung. The trachea and bronchi were palpated and the endotracheal tube was found to be correctly placed. Despite this the endotracheal tub: was replaced by a short 9 mm Magill cuffed endotrachial tube and again an