ABSTRACT
In this prospective, randomised, double-blind study, we compared the effects of two dosage regimens. Pregnant patients at term were randomly assigned to two groups to be given diamorphine 0.4 mg in hyperbaric bupivacaine 0.5% 2.4 ml or diamorphine 0.4 mg in a volume of hyperbaric bupivacaine 0.5% adjusted according to the patient's height and weight. Adequate anaesthesia was provided in all patients in both groups. The onset of the sensory block for cold and pinprick was faster with the fixed dose regimen (p = 0.01). There were more spinal blocks to above the first thoracic dermatome in the fixed dose group (17.1% vs. 2.2%, p = 0.022). Hypotension occurred in 71.7% vs. 50.0% of patients in the fixed dose and adjusted dose groups respectively (p = 0.035). In the fixed dose group, more patients required ephedrine to treat hypotension (79.5% vs. 56.8%, p = 0.022) and a larger median dose was administered (9 mg vs. 6 mg, p = 0.042). The decrease in mean (SD) arterial pressure was less in the adjusted group (35.0 (16.4) mmHg vs. 28.0 (13.5) mmHg, p = 0.036).
Subject(s)
Anesthesia, Obstetrical/methods , Anesthesia, Spinal/methods , Anesthetics, Local/administration & dosage , Bupivacaine/administration & dosage , Cesarean Section , Heroin/administration & dosage , Adult , Anesthetics, Local/adverse effects , Body Height , Body Weight , Bupivacaine/adverse effects , Double-Blind Method , Drug Administration Schedule , Ephedrine/therapeutic use , Female , Heroin/adverse effects , Humans , Hypotension/chemically induced , Hypotension/drug therapy , Pregnancy , Prospective Studies , Vasoconstrictor Agents/therapeutic useABSTRACT
A 28-year-old primigravida at 35 weeks gestation with acute onset of dyspnoea and stridor due to an intrathoracic neoplasm required semi-urgent caesarean section to allow diagnosis and treatment. Her inability to lie supine precluded regional anaesthesia. She underwent awake fibreoptic oral intubation followed by general anaesthesia. This was complicated by desaturation, high airway pressures, unilateral lung collapse, venous congestion and unexpected blood loss due to an undiagnosed placenta praevia.
