Neonatal effects and efficacy of dexmedetomidine on haemodynamics during cesarean section under general anesthesia

Abstract

Objective To explore the neonatal effects and efficacy of dexmedetomidine on haemodynamics during cesarean section under general anesthesia.Methods Thirty-eight ASA Ⅰ or Ⅱ parturients with a single baby at full term in vertex presentation,scheduled for cesarean section under general anesthesia,were randomly divided into 2 groups (each group of 19 patients) by random digits table method:dexmedetomidine group and normal saline group.The patients in dexmedetomidine group received an intravenous infusion loading dose of 0.6 μ g/kg of dexmedetomidine,starting 10 min before induction of anesthesia,following with an intravenous infusion 0.4 μ g/ (kg ·h) of dexmedetomidine until peritoneal closure.The patients in normal saline group received an intravenous infusion of isovolumic of normal saline.Recording the systolic blood pressure (SBP),diastolic blood pressure (DBP) and heart rate (HR) before infusion (T0) and 10 min after the start of infusion (T1),at tracheal intubation (T2),at delivery of the baby (T3),15 min after delivery (T4),at end of operation (T5),at extubation (T6) and 15 min after extubation (T7).The blood of umbilical vein and umbilical artery was drawn for gas analysis,and the Apgar scores at 1 and 5 min were also recorded after delivery.Results The level of SBP,DBP and HR at T0 had no significant difference between two groups (P ＞ 0.05).In dexmedetomidine group,the level of SBP,DBP and HR were significantly higher at T2 than those at T0 [(136 ± 12) mmHg (1 mmHg =0.133 kPa) vs.(124 ± 9) mmHg,(83 ± 10) mmHg vs.(72 ± 6) mmHg,(93 ± 11) times/min vs.(81 ± 8) times/min] (P ＜ 0.05).In normal saline group,the level of SBP,DBP and HR at T2-6 [(151 ± 14),(137 ± 11),(132 ± 10),(132 ±9),(142± 13)mmHgvs.(125 ±9)mmHg;(94±13),(85±9),(80±8),(80±9),(86±11)mmHgvs.(74 ±7) mmHg; (122 ±15),(105 ±12),(90 ±9),(89 ± 10),(97 ±11) times/min vs.(81 ±9) times/min] were significantly lower (P ＜ 0.05).Compared with normal saline group,the level of SBP,DBP and HR were lower in dexmedetomidine group at T2-6(P ＜ 0.05).There were no significant difference not only about the blood gas analysis of umbilical vein and umbilical artery,but also about the Apgar scores at 1 and 5 min after delivery (P ＞ 0.05).Conclusion Administration of dexmedetomidine is effective in maintaining the maternal haemodynamic during the cesarean section under general anesthesia without adverse neonatal effects. Key words: Dexmedetomidine; Anesthesia; Cesarean section; Haemodynamics; Newborn