Acute airway obstruction during spinal anaesthesia for caesarean section.

A 30-year-old primiparous Caucasian woman with known placenta praevia required an emergency caesarean section for a mild antepartum haemorrhage at the onset of spontaneous term labour. Following intravenous prehydration with 500 ml gelatin colloid (Haemaccel trade mark ), spinal anaesthesia was induced in the sitting position with 2.6 ml of 0.5% hyperbaric bupivacaine (13 mg). The patient was then placed in the recumbent position with left lateral tilt, whereupon she suddenly became dyspnoeic. A generalized erythematous urticarial rash with associated facial, periorbital, glossal and perioral oedema became evident. Although maternal blood pressure remained within normal limits, emergency conversion to general anaesthesia with tracheal intubation was necessary to secure the airway. Laryngoscopy revealed gross submucosal, epiglottic and pharyngeal oedema, characteristics of the syndrome of angioneurotic oedema, which may complicate an anaphylactoid reaction. After the airway was secured with a cuffed endotracheal tube, caesarean section proceeded uneventfully and a healthy male infant was delivered. Maternal facial and airway oedema subsided and extubation was performed in intensive care 2 h later. Life-threatening airway obstruction often accompanies angioneurotic oedema. Since parturients have a higher incidence of difficult airway management than the general population, anaphylactoid reactions presenting as angioneurotic oedema pose a particular challenge for the anaesthetist. The lower incidence of allergy associated with hydroxyethyl starch (Hetastarch) may make it a more appropriate choice of colloid in this setting. However, the balance of evidence now suggests that vasopressors, particularly ephedrine, are superior to fluids for maintenance of blood pressure during regional anaesthesia for caesarean section.