///2014 Abstract Details
2014 Abstract Details2019-07-18T14:34:47-06:00

Prophylactic bolus administration of phenylephrine can prevent spinal hypotension during caesarean delivery: a randomized double blind study

Abstract Number: T-52
Abstract Type: Original Research

ju-hyun Lee M.D1 ; ju-hyun Lee M.D2; hwa-mi Lee M.D3; woo-jong Choi M.D. , Ph.D.4

Background: One of treatments for spinal hypotension in the caesarean delivery is continuous infusion of phenylephrine (PEPH). However, continuous infusion method required large amount of phenylephrine. Though PEPH is relatively safe in the pregnancy, high dose of PEPH might be associated with reduction of maternal heart rate, which could consequently reduce maternal cardiac output. Prophylactic bolus injection of PEPH, instead of continuous infusion, may effectively prevent spinal hypotension with lower amount of PEPH. This double-blind, randomized, controlled study was designed to investigate of the effect of prophylactic PEPH treatment on preventing spinal hypotension during caesarean delivery. The appropriate dose of bolus injection was also investigated.

Methods: we recruited 184 ASA physical status I and II women with term singleton pregnancies scheduled for elective caesarian delivery under combined spinal-epidural anaesthesia. Patients in control group were received 2ml of normal saline. Patients in PEPH 1, PEPH 1.5 and PEPH 2 groups were received 2ml solutions of 1 µg/kg, 1.5 µg/kg, and 2 µg/kg of phenylephrine mixed in normal saline, respectively. Spinal anaesthesia was conducted in the left lateral position at the L3-4 interspace with 0.5% hyperbaric bupivacaine 7 mg and fentanyl 15 µg. an anaesthesiologist blinded to group allocation injected 2ml of normal saline mixed phenylephrine or normal saline intravenously. Blood pressure and heart rate were recorded at 1 minute intervals until the time of delivery. If the systolic blood pressure (SBP) decreased by 20% from the baseline value, 50 µg of phenylephine was given. When bradycardia (HR < 50 beats/min) occurred with hypotension, 0.5 mg of atropine was administered. We investigated obstetric data including time from the intrathecal injection to skin incision, uterine incision, and delivery, neonatal Apgar scores at 1 and 5 minutes and umbilical artery and venous pH and Pco2.

Results:The incidence of spinal hypotension were significantly higher in control group (71%, n=33) and PEPH 1 (69%, n=31) compared with PEPH 1.5 (37%, n=17) and PEPH 2 (46%, n=21) (p=0.001). Control group and PEPH 1 group required significantly larger amount of additive phenylephrine than PEPH 1.5 and PEPH 2 group (p<0.001). PEPH 2 group showed significantly higher incidence of reactive hypertension compared with other groups (37%, n=17, p<0.001). The incidences of nausea or bradycardia were not significantly different among groups (p=0.054, p=0.870, respectively).

Conclusion: Prophylactic bolus injection of 1.5 µg/kg PEPH reduces the risk of spinal hypotension and avoid adverse effects of high-dose PEPH.


Ngan Kee WD, Khaw KS, Ng FF, Lee BB. Prophylactic phenylephrine infusion for preventing hypotension during spinal anesthesia for cesarean delivery. Anesthesia and analgesia 2004; 98: 815-21.

SOAP 2014