Haemodynamic effects of remifentanil in children with and without intravenous atropine. An echocardiographic study

Background. Remifentanil is known to cause bradycardia and hypotension.We aimed to characterize the haemodynamic profile of remifentanilduring sevoflurane anaesthesia in children with or without atropine. Methods. Forty children who required elective surgery receivedinhalational induction of anaesthesia using 8% sevoflurane.They were allocated randomly to receive either atropine, 20µg kg^–1 (atropine group) or Ringer's lactate (controlgroup) after 10 min of steady-state 1 MAC sevoflurane anaesthesia(baseline). Three minutes later (T0), all children receivedremifentanil 1 µg kg^–1 injected over a 60 s period,followed by an infusion of 0.25 µg kg^–1 min^–1for 10 min then 0.5 µg kg^–1 min^–1 for 10 min.Haemodynamic variables and echocardiographic data were determinedat baseline, T0, T5, T10, T15 and T20 min. Results. Remifentanil caused a significant decrease in heartrate compared with the T0 value, which was greater at T20 thanT10 in the two groups: however, the values at T10 and T20 werenot significantly different from baseline in the atropine group.In comparison with T0, there was a significant fall in bloodpressure in the two groups. Remifentanil caused a significantdecrease in the cardiac index with or without atropine. Remifentanildid not cause variation in stroke volume (SV). In both groups,a significant increase in systemic vascular resistance occurredafter administration of remifentanil. Contractility decreasedsignificantly in the two groups, but this decrease remainedmoderate (between –2 and +2 SD). Conclusion. Remifentanil produced a fall in blood pressure andcardiac index, mainly as a result of a fall in heart rate. Althoughatropine was able to reduce the fall in heart rate, it did notcompletely prevent the reduction in cardiac index.