Phenylephrine is currently the vasopressor of choice during elective caesarean section, but it can cause reflex bradycardia. Noradrenaline, a potent a-agonist and weak b-agonist, may be associated with a lower incidence of bradycardia. However, comparative information is limited. This double-blind randomised controlled trial compared the effects of 100 lg phenylephrine and 5 lg noradrenaline administered as boluses for the treatment of postspinal hypotension during elective caesarean section in women with an uncomplicated singleton pregnancy. Hypotension was defined as a decrease of ≥ 20% from baseline systolic arterial pressure, or an absolute value < 100 mmHg. Ninety women were included in the study. The primary outcome was the incidence of maternal bradycardia < 60 beats.min À1 . There was no difference in the incidence of bradycardia (37.8% with phenylephrine vs. 22.2% with noradrenaline; p = 0.167), number of hypotensive episodes, number of boluses required to treat the first hypotensive episode or reactive hypertension. The total number of boluses used was higher in the phenylephrine group (p = 0.01). Maternal heart rate at 1 min after vasopressor administration was non-significantly lower using phenylephrine vs. noradrenaline (p = 0.034, considering p < 0.01 as statistically significant). The umbilical artery pH was higher using phenylephrine than with noradrenaline (p = 0.034). In conclusion, both vasopressors reversed postspinal hypotension without a statistically significant difference in maternal bradycardia. However, in view of the lower umbilical artery pH when using noradrenaline, further research is warranted to study its placental transfer and fetal metabolic effects.

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Background and Aims:Recently, low-dose intravenous (IV) dexmedetomidine has been evaluated for obtunding the pneumoperitoneum-induced haemodynamic changes and its analgesic efficacy in laparoscopic cholecystectomy. The aim was to determine the postoperative analgesic efficacy of low-dose bolus of 0.5 μg/kg dexmedetomidine via IV and intraperitoneal (IP) route in laparoscopic cholecystectomy.Methods:Seventy-five patients, aged 18–60 years of ASA physical status I and II, undergoing laparoscopic cholecystectomy under general anaesthesia were included. Patients in Group C received IP bupivacaine. Patients in Group IV received 0.5 μg/kg dexmedetomidine infusion IV after removal of gall bladder along with IP bupivacaine and Group IP received 0.5 μg/kg dexmedetomidine in 40 mL of 0.25% bupivacaine IP. The primary outcome was 'time to first request of analgesia' and the secondary outcomes were 'total consumption of tramadol in 24 hours,' visual analogue scale (VAS) pain score.Results:In total, 75 patients with 25 in each group were included. Time to first request of analgesia was found to be significantly lower in IV (59.68 ± 71.05 min, P = 0.00) and IP group (90.80 ± 80.46 min, P = 0.001) compared tp Group C (59.68 ± 71.05 min). Mean tramadol consumption in 24 hours (152.40 ± 60.958 vs 137.64 ± 52.40 mg) and mean VAS pain score were comparable in both IV and IP groups in the initial 12 h.Conclusion:Low bolus dose of IP dexmedetomidine is as efficacious as IV dexmedetomidine (0.5 μg/kg) along with IP bupivacaine in laparoscopic cholecystectomy.