Comparison of the effects of low doses of dexmedetomidine and remifentanil on the maternal hemodynamic changes during caesarean delivery in patients with severe preeclampsia: a randomized trial.

BACKGROUND

Preoperative remifentanil administration blunts hemodynamic responses to tracheal intubation in parturients with severe preeclampsia. We hypothesized that the preoperative administration of low doses of remifentanil or dexmedetomidine would lead to comparable maternal neurohormonal responses and neonatal outcomes in patients with severe preeclampsia.

METHODS

Parturients diagnosed with severe preeclampsia undergoing caesarean delivery were randomLy allocated to receive remifentanil (0.1 µg/kg/min) or dexmedetomidine (0.4 µg/kg/h) at five min and 20 min before induction, respectively. Changes in maternal mean arterial BP(MAP), clinical recovery, cortisol level, and neonatal outcome, were recorded.

RESULTS

Patients who received remifentanil had higher response in MAP at the induction (94 9.8 vs. 104 4.5; P<0.001) and emergence from anesthesia (94 6.3 vs. 98 5.1; P<0.001), but shorter times to extubation (5.1 1.6 vs. 13.5 2.8 min; P<0.001). Five (27.8%) patients in the remifentanil group received ephedrine versus none in the dexmedetomidine group (P=0.023). The maternal plasma cortisol levels, the neonatal Neurologic and Adaptative Capacity Scores and acid-base satuses were similar in the two groups. Newborns in the remifentanil group presented lower Apgar scores at 1 minute (5.11 0.8 vs. 5.68 0.8; P=0.034) and a higher incidence of respiratory depression (72.2% vs. 36.8% P=0.048).

CONCLUSIONS

Compared with dexmedetomidine (0.4 µg/kg/h), the preoperative administration of remifentanil (0.1 µg/kg/min) produced a significantly higher effect on maternal hemodynamic responses to caesarean delivery in patients with severe preeclampsia, however maternal hypotension and neonatal respiratory depression were more common with the use of remifentanil.