Medication errors contributing to obstetric cardiac arrest in NAP7

It is reassuring to see that obstetric patients are four times less likely to experience a cardiac arrest than patients having non-obstetric surgery [1]. Further, no cardiac arrests were attributed to failed tracheal intubation, aspiration, local anaesthetic systemic toxicity or remifentanil patient-controlled analgesia, suggesting significant safety improvements in these areas. Anaesthesia-related factors were reported to be the leading cause of cardiac arrest including a high neuraxial block, bradyarrhythmia during anaesthesia and hypotension associated with general anaesthetic administered following inadequate neuraxial anaesthesia or haemorrhage. This finding is not too dissimilar to the cardiac arrest in pregnancy study published in 2017 [2]. Medication errors were another cause of cardiac arrest in two patients (7%). No specific details of these medications or the route of their administration and the settings in which these occurred (e.g. operating theatre, labour ward, time of the day) are provided in the article or supporting information. More recently, severe harm, cardiac arrest and maternal death from inadvertent neuraxial administration of tranexamic acid and digoxin during caesarean birth have been reported [3, 4]. A recent national survey on medication errors in maternity units across the UK reported syringe swaps and wrong route administration as the most common in obstetric anaesthesia [5]. Considering medication errors in obstetrics are potentially avoidable and can have a significant bearing on maternal and neonatal outcomes and subsequent healthcare costs (e.g. litigation), it would be useful if the authors could provide more details of these errors, and the associated outcomes to inform the anaesthetic fraternity and enhance safety in obstetric anaesthesia.