Cardiopulmonary distress during obstetrical anaesthesia: Attempts to diagnose amniotic fluid embolism in a case series of suspected allergic anaphylaxis

Abstract

Background: Cardiopulmonary distress during obstetrical anaesthesia may result from a drug-induced allergic reaction, but, in the obstetrical setting, allergic anaphylaxis may be inseparable from amniotic fluid embolism in terms of the clinical presentation. Further investigations, using allergy tests and other laboratory analyses, are then needed to pursue a diagnostic clarification. Methods: Twelve women suspected of having developed anaphylaxis during obstetrical anaesthesia underwent allergy follow-up investigations and further serological tests with the amniotic fluid embolism marker sialyl Tn and complement factors (C3 and C4) in an attempt to differentiate amniotic fluid embolism from drug-induced allergic anaphylaxis. Results: The diagnostic programme revealed one case of probable amniotic fluid embolism and four cases of probable drug-induced allergic anaphylaxis. Of the remaining seven cases, there were two cases that, by diagnostic exclusion, could be classified as possible cases of amniotic fluid embolism. The cause of the reactions remained unresolved in five cases. Conclusions: It can be difficult to differentiate between anaphylaxis and amniotic fluid embolism, especially amongst survivors. Diagnostic markers that can be applied on peripheral blood samples are promising, but larger studies are needed to validate their use in the diagnosis of causes of cardiopulmonary distress during obstetrical anaesthesia. © Acta Anaesthesiologica Scandinavica (2006).