Amniotic fluid embolism: a leading cause of maternal death yet still a medical conundrum.

Amniotic fluid embolism is a rare and potentially catastrophic condition that is unique to pregnancy. The presentation may range from relatively subtle clinical events to sudden maternal cardiac arrest. Despite an increased awareness of the condition, it remains a leading cause of maternal mortality. The underlying mechanisms of amniotic fluid embolism are poorly understood, but current theories support an immune-based mechanism which is triggered by potentially small amounts of amniotic fluid gaining access to the maternal circulation. This can result in a wide spectrum of clinical findings, with cardiovascular and haematological disturbances being prominent. The management of a suspected episode of amniotic fluid embolism is generally considered to be supportive, although in centres with specific expertise, echocardiography may assist in guiding management. Whilst outcomes after an episode of amniotic fluid embolism are still concerning, mortality would appear to have decreased in recent times, likely secondary to an improved awareness of the condition, advances in acute care and the inclusion of less severe episodes in case registries.

Single dose dexamethasone for postoperative nausea and vomiting--a matched case-control study of postoperative infection risk.

Dexamethasone is an effective prophylaxis against postoperative nausea and vomiting but is immunosuppressive and may predispose patients to an increased postoperative infection risk. This matched case-control study examined the association between the administration of a single intraoperative anti-emetic dose of dexamethasone (4 to 8 mg) and postoperative infection in patients undergoing non-emergency surgery in a university trauma centre. Cases were defined as patients who developed infection between one day and one month following an operative procedure under general anaesthesia. Controls who did not develop infection were matched for procedure, age and gender Exclusion criteria included immunosuppressive medications, chronic glucocorticoid therapy, cardiac surgical and solid-organ transplantation procedures. Sixty-three cases and 172 controls were identified. Cases were more likely to have received dexamethasone intraoperatively (25.4 vs. 11%, P = 0.006), and less likely to have received perioperative antibiotic prophylaxis (60.3 vs. 84.3%, P = 0.001). Stepwise, multivariate conditional logistic regression confirmed these associations, with adjusted odds ratios of 3.03 (1.06 to 19.3, P = 0.035) and 0.12 (0.02 to 0.7, P = 0.004) respectively for the associations between dexamethasone and perioperative antibiotic prophylaxis, with postoperative infection. We conclude that intraoperative administration of dexamethasone for anti-emetic purposes may confer an increased risk of postoperative infection.