A comparative study of three concentrations of intravenous nalbuphine combined with hydromorphone for post-cesarean delivery analgesia

Background:Nalbuphine has been suggested to be used for post-cesarean section(CS)intravenous analgesia.However,ideal concentration of nalbuphine for such analgesia remains unclear.The present study was conducted to explore an ideal concentration of nalbuphine for post-CS intravenous analgesia by evaluating the analgesic effects and side-effects of three different concentrations of nalbuphine combined with hydromorphone for post-CS intravenous analgesia in healthy parturients.Methods:One-hundred-and-fourteen parturients undergoing elective CS were randomly allocated to one of three groups(38 subjects per group)according to an Excel-generated random number sheet to receive hydromorphone 0.05 mg/mL+nalbuphine 0.5 mg/mL(group LN),hydromorphone 0.05 mg/mL+nalbuphine 0.7 mg/mL(group MN),and hydromorphone 0.05 mg/mL+nalbuphine 0.9 mg/mL(group HN)using patient-controlled analgesia(PCA)pump.Visual analog scale(VAS)for pain,PCA bolus demands,cumulative PCA dose,satisfaction score,Ramsay score,and side-effects such as urinary retention were recorded.Results:The number of PCA bolus demands and cumulative PCA dose during the first 48 h after CS were significantly higher in group LN(21±16 bolus,129±25 mL)than those in group MN(15±10 bolus,120±16 mL)(both P<0.05)and group HN(13±9 bolus,117±13 mL)(both P<0.01),but no difference was found between group HN and group MN(both P>0.05).VAS scores were significantly lower in group HN than those in group MN and group LN for uterine cramping pain at rest and after breast-feeding within 12 h after CS(all P<0.01)and VAS scores were significantly higher in group LN than those in groupMNand group HN when oxytocin was intravenously infused within 3 days after CS(all P<0.05),whereas VAS scores were not statistically different among groups for incisional pain(all P>0.05).Ramsay sedation scale score in groupHNwas significantly higher than that in group MN at 8 and 12 h after CS(all P<0.01)and group LN at 4,8,12,24 h after CS(all P<0.05).Conclusions:Hydromorphone 0.05 mg/mL+nalbuphine 0.7 mg/mL for intravenous PCA could effectively improve the incisional pain and uterine cramping pain management and improve comfort in patients after CS.