We designed a randomized, double-blinded study to determine the efficacy and safety of 0.5 mg/kg intravenous ephedrine for the prevention of hypotension during spinal anesthesia for cesarean delivery. Patients were randomly allocated into two groups: ephedrine group (n=21) and control group (n=21). Intravenous preload of 15 mL/kg lactated Ringer's solution was given. Shortly after the spinal injection, ephedrine 0.5 mg/kg or saline was injected intravenous for 60 sec. The mean of highest and lowest heart rate in the ephedrine group was higher than those of control group (P<0.05). There were significant lower incidences of hypotension and nausea and vomiting in the ephedrine group compared with the control group (8 [38.1%] vs. 18 [85.7%]); (4 [19%] vs. 12 [57.1%], respectively) (P<0.05). The first rescue ephedrine time in the ephedrine group was significantly longer (14.9+/-7.1 min vs. 7.9+/-5.4 min) than that of the control group (P<0.05). Neonatal outcome were similar between the study groups. These findings suggest, the prophylactic bolus dose of 0.5 mg/kg intravenous ephedrine given at the time of intrathecal block after a crystalloid fluid preload, plus rescue boluses reduce the incidence of hypotension.
Adult ; *Anesthesia, Spinal/adverse effects ; Blood Pressure/drug effects ; *Cesarean Section ; Ephedrine/administration & dosage/*therapeutic use ; Female ; Heart Rate/drug effects ; Humans ; Hypotension/chemically induced/prevention & control ; Injections, Intravenous ; Postoperative Nausea and Vomiting/prevention & control ; Pregnancy ; Vasoconstrictor Agents/administration & dosage/*therapeutic use

The aim of this study was to evaluate the synergistic potentiation effect of ineffective doses of dexmedetomidine on antinociception induced by morphine and fentanyl in acute pain model in rats. Seventy albino Wistar rats were separated into 7 groups. Data for the control and sham groups were recorded. The ineffective dose of dexmedetomidine was investigated and found to be 3 micro g/kg. Each group was administered the following medications: 3 mg/kg morphine (intraperitoneal) to Group 3, 5 microg/kg fentanyl (intraperitoneal) to Group 4, dexmedetomidine 3 micro g/kg (subcutaneously) to Group 5, dexmedetomidine 3 microg/kg (subcutaneous)+3 mg/kg morphine (intraperitoneal) to Group 6 and finally 3 microg/kg dexmedetomidine (subcutaneous)+5 microg/kg fentanyl (intraperitoneal) to Group 7. Just before the application and 15, 30, 60, 90 and 120 min after the administration of medication, two measurements of tail flick (TF) and hot plate (HP) tests were performed. The averages of the measurements were recorded. TF and HP latencies were the main outcomes. The analgesic effect of the combinations with dexmedetomidine+morphine (Group 6) and dexmedetomidine+fentanyl (Group 7), compared to the analgesic effect of morphine alone and fentanyl alone was significantly higher at 15, 30, 60 and 90 minutes after administration. In this study, dexmedetomidine in ineffective doses, when combined with morphine and fentanyl, potentiates the effects of both morphine and fentanyl.
Acute Pain* ; Animals ; Dexmedetomidine* ; Fentanyl* ; Morphine* ; Rats ; Rats, Wistar