剖宫产术患者瑞芬太尼辅助用药对新生儿的影响及其胎盘转移

目的 探讨剖宫产术患者瑞芬太尼辅助用药对新生儿的影响及其胎盘转移情况.方法 择期足月剖宫产术患者40例,初产,ASA Ⅰ级,年龄26～32岁,体重70～90 kg,随机分为2组(n=20),对照组(C组)和瑞芬太尼组(R组).于L3-4间隙穿刺行脊椎-硬膜外联合阻滞,控制阻滞平面上界T6-T8.R组靶控输注瑞芬太尼,血浆靶浓度1.5 ng/ml,C组按瑞芬太尼的血浆靶控模式和靶浓度输注生理盐水,血样采集完毕时停止输注.于入室平静5 min(T0)、切皮(T1)、胎儿娩出(T2)、子宫修补(T3)和关腹(T4)时记录MAP、HR、分钟通气量(MV)、呼吸频率(RR>、警觉,镇静评分(OAA/S评分);记录T0时和消毒前胎心率(FHR)、子宫切开到胎儿娩出时间(分娩时间)、新生儿体重、新生儿1、5 minApgar评分、1、24 h新生儿神经行为评分(NBNA)和患者不良反应发生情况.胎儿娩出后3 min内分别取脐动脉血(UA)、脐静脉血(UV)各2 ml,于足背动脉取母体动脉血(MA)2 ml,行血气分析,测定瑞芬太尼血浆浓度.结果 与C组和T0时比较,R组T1,2时OAMS评分降低(P<0.05).两组间MAP、HR、MV、RR、分娩时间、FHR、血气分析指标、新生儿体重、Apgar评分和NBNA评分的比较差异无统计学意义(P>0.05),且均在正常范围内.胎儿娩出时MA、UV及UA中瑞芬太尼血浆浓度分别为(0.85±0.31)、(0.57±0.12)、(0.22±0.09) ng/ml,CUV/CMA为0.67±0.41,CUA/CUV为0.39±0.08.结论 靶控输注瑞芬太尼(血浆靶浓度1.5 ng/ml)时,尽管瑞芬太尼可迅速进行胎盘转移,但进入胎儿体内后,可迅速被代谢或重分布,因而对新生儿无不良影响.

Placental transfer and neonatal effects of remifentanil as an adjuvant for cesarean section

Objective To investigate the placental transfer and neonatal effects of remifentanil as an adjuvant for cesarean section.Methods Forty ASA Ⅰ parturients at full term aged 26-32 yr weighing 70-90 kg undergoing elective cesarean section under combined spinal epidural anesthesia (CSEA) were randomly divided into 2 groups (n = 20 each): control group (C) and remifentanil group (R). The CSEA was performed at L3-4interspace and the upper spread of sensory block reached T6-8. Group R received TCI of remifentanil (target plasma concentration was set at 1.5 ng/ml) starting from performance of CSEA until blood samples were obtained. In group C equal volume of normal saline was infused instead of remifentanil. MAP, HR, RR, minute ventilation (MV), and OAA/S scores were recorded after the parturients had settled down for 5 min in the operating room (T0), at skin incision (T1), when the baby was being delivered (T2), uterus repaired (T3) and peritoneum closed (T4). Fetal heart rate (FHR) at T0 and immediately before skin disinfection, the duration between uterus incision and delivery of the baby (delivery time), body weight of the newborn, Apgar score at 1 min and 5 min after delivery and neonatal behavioral neurological assessment (NBNA) at 1 h and 24 h after delivery were also recorded.Adverse effects including hypotension, sinus bradycardia, raspiratory depression, muscle rigidity , nausea and vomiting were recorded. The middle segment of umbilical cord (about 10-15 cm long) was clamped at both ends with two clamps at delivery. Umbilical arterial (UA) and venous (UV) blood samples and maternal arterial (MA) blood samples were obtained within 3 min after delivery for blood gas analysis and determination of plasma remifentanil concentration using C,C-MS-SIM method. Results OAA/S scores were significantly lower at T1,2 in group R than in group C. There were no significant differences in MAP, HR, MY, RR, delivery time, FHR, blood gases, bedy weight of the newborn, Apgar scores and NBNA scores between the 2 groups. The plasma concentrations (C) of remifentanil were (0.85±0.31),(0.57±0.12) and (0.22±0.09) ng/ml respectively in maternal arterial, umbilical venous and arterial blood samples, CUV/CMA was 0.67±0.41 and CUA/CUV was 0.39±0.08. Conclusion Remifentanil given by TCI at a target plasma concentration of 1.5 ng/ml has no adverse effects on the newborn because of raid metabolism and redistribution of remlfentanil in the neonate after rapid placental transfer.