Examining the influence of maternal bradycardia on neonatal outcome using automated data collection

Background

Due to the increasing number of caesarean sections, we investigated the influence of maternal bradycardia during general and regional anaesthesia on seven standard paediatric outcome parameters using our online recorded data.

Methods

Data from 1154 women undergoing caesarean section were investigated prospectively. Bradycardia was defined as a heart rate below 60 beats/min. The matched-pairs method was used to evaluate the impact of bradycardia on Apgar scores at 1, 5, and 10 min, umbilical artery pH and base excess, admission to paediatric intensive care unit, and seven-day mortality. Matched references were automatically selected among all patients from the data pool according to anaesthetic technique, sensory block height, urgency, maternal age and body mass index. Stepwise regression models were developed to predict the impact of intra-operative bradycardia on outcome variables with differences between matched pairs assessed using univariate analysis.

Results

Bradycardia was found in 146 women (12.7%) for whom a control could be matched in 131 cases (89.7%). Mean 5-minute Apgar score was 9.2±1.1 for study patients and 9.3±1.1 for controls. pH and base excess were not significantly different between groups. In cases of urgent surgery, neonates had an increased risk of 1.8 (95% CI 1.36-2.44, P<0.01) for an Apgar score ⩽8 at 1 min and a 2.6-fold risk (95% CI 1.64-4.06, P<0.01) of umbilical arterial pH of ⩽7.2 compared to infants undergoing non-urgent procedures.

Conclusions

Using matched-pairs analysis we were unable to demonstrate that episodes of maternal bradycardia below 60 beats/min were associated with a poorer neonatal outcome regardless of anaesthetic technique.

Keywords: Caesarean section, Data management system, Bradycardia, Matched-pairs analysis, Neonatal outcome, Anaesthesia