Articles from British journal of anaesthesia 1998 January

Br J Anaesth · Jan 1998

Randomized Controlled Trial Clinical Trial

Effect of dexamethasone on postoperative emesis and pain.

In this double-blind, randomized, placebo-controlled study, we have evaluated the effect of preoperative administration of dexamethasone on postoperative vomiting and pain in 60 women undergoing general anaesthesia for major gynaecological surgery. Dexamethasone 10 mg (group D) or saline (group S) was administered i.v. in a double-blind manner during induction of anaesthesia. ⋯ Six patients in group D and 19 in group S experienced vomiting at least once within the 24-h postoperative period; dexamethasone was effective in reducing the overall incidence of vomiting from 63.3% to 20.0% (P < 0.01). Other variables were similar between the groups, and the influence of dexamethasone on postoperative pain was minimal.

Effect of positive end-expiratory pressure on the incidence of venous air embolism and on the cardiovascular response to the sitting position during neurosurgery.

We have studied prospectively the effect of 10 cm H2O of PEEP on the incidence of venous air embolism and on the cardiovascular response to change from the supine to the seated position in a large neurosurgical population. Patients were allocated randomly to receive either PEEP (10 cm H2O, n = 45) or conventional (control, n = 44) ventilation. Cardiovascular and respiratory variables were measured in the supine and sitting positions, and monitoring included precordial Doppler probe, pulmonary artery pressure and expiratory carbon dioxide concentration. ⋯ Furthermore, pulmonary vascular resistance increased significantly only in the upright position in those undergoing ventilation with PEEP. The pulmonary artery wedge pressure to central venous pressure gradient did not attain negative values with PEEP or with upright positioning. We conclude that the use of PEEP during neurosurgical procedures performed in the sitting position should be abandoned as it does not decrease the incidence of venous air embolism but is associated with significant adverse cardiovascular effects.

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Br J Anaesth · Jan 1998

Multicenter Study

Mast cell tryptase in anaesthetic anaphylactoid reactions.

Increased concentrations of mast cell tryptase are a highly sensitive indicator of anaphylactic reactions during anaesthesia. We obtained serum specimens from 350 patients after possible anaphylactic reactions during anaesthesia. Serum was collected from patients in our own institution (27), and transported by mail and courier from other hospitals in response to a request in the medical literature (323). ⋯ Seven of 143 patients whose mast cell tryptase concentrations were not increased at appropriate sampling times had positive tests for IgE antibodies, and in 33 of 158 patients with increased mast cell tryptase concentrations no IgE antibodies were detected. We conclude that increased mast cell tryptase concentrations are a valuable indicator of an anaphylactic reaction during anaesthesia. Their presence favours an IgE-mediated cause but does not always distinguish between anaphylactoid and anaphylactoid reactions, and patients in whom mast cell tryptase concentrations are not increased still require skin testing.