Discussion
A revised definition for anaphylaxis is “a rapid onset serious systemic hypersensitivity reaction that has potential to cause death. It is characterized by compromise in breathing that is potentially life threatening and/or circulatory collapse, and may occur in the absence of typical skin features or circulatory shock” (8). Our patient developed sudden onset respiratory depression immediately following administration of IV tramadol which is consistent with the world allergy organization’s (WAO) amended diagnostic criteria for anaphylaxis (8).
The prevalence of anaphylaxis in pregnancy was 2.7 cases per 1,00,000 deliveries (95% confidence interval, 1.7-4.2 cases per 1,00,000 deliveries). β-lactams antibiotics were responsible for anaphylaxis in 11out of 19 patients (3). Tramadol is commonly used as labor analgesics at Jigme Dorji Wangchuck National Referral Hospital, Bhutan. This is the first anaphylaxis during intrapartum period due to tramadol in this hospital. Whereas, the reported trigger for anaphylaxis during pregnancy was β-lactam antibiotics (3).
Ideally, perimortem caesarean section should be performed within 5 minutes of maternal cardiac arrest(9). However, in a systematic review on management of cardiac arrest in pregnancy, perimortem caesarean section within recommended 4-5 mins of cardiac arrest was performed in 8 out of 38 cases. Perimortem caesarean section in 30-38 weeks pregnancy done after recommended 5 minutes has shown successful maternal and neonatal outcomes (9). In our case, emergency caesarean section was done 87 minutes after maternal respiratory arrest and endotracheal intubation with live baby with APGAR score of 8/10 and 10/10 at one and five minutes of birth respectively. The successful neonatal outcome can be attributed to abrupt and successful intubation and maintenance of oxygen saturation. Her cardiac function was stable and she was kept in left lateral tilt of 150 from the horizontal as per the International Liaison Committee on Resuscitation (ILCOR) consensus on science and treatment recommendations of 2005 (10) and the 2005 European Resuscitation Council Guidelines (11).
The 57 minutes delay between onset of respiratory arrest and caesarean section was because of delay in GeneXpert report. As Bhutan was in second nationwide lockdown due to surge in community spread of SARS-COVID 19, emergency patients need COVID-19 GeneXpert report negative to shift from ER to operation room (OR) and there is no emergency OR available in ER. 
The sensitivity of Xpert Xpress SARS-CoV-2 assays (GeneXpert) was 100% and the specificity was 80% for the diagnosis of COVID-19 in low middle income countries (LMICs) (12).
Healthy mother and newborn was discharged home on third postoperative day which corresponds with the length of hospital stay in other studies (3).