Plasma concentrations of tryptophan and dieting.

(1) Lung function should be adequate and stable before transfer. (2) Humidification of inspired air should be adequate before and during transport, particularly for patients with an endotracheal tube or tracheostomy. If secretions are sticky 2 ml ofwarm saline can be passed down the endotracheal tube or tracheostomy tube at frequent intervals. (3) Supplemental oxygen should be available. (4) Patients should be accompanied by someone trained in manouevres to clear secretions from patients with spinal ijuries4 and prepared to perform tracheal suction frequently. (5) Intravenous atropine should be available. Tracheal suction in patients with high spinal injuries may precipitate life threatening bradycardia.' The incidence of such bradycardia is reduced by preoxygenation before suction and the skilful use ofthe suction catheter. If appreciable bradycardia develops intravenous atropine should be given. Patients prone to serious bradycardias may be treated with an oral adrenal agonist such as orciprenaline before the flight.