Prophylactic Ephedrine versus Phenylephrine for Maternal Hypotension in Women Undergoing Spinal Anesthesia for Caesarean Section - A randomized Double Blind Clinical Trial
Qussai Ussbah ¹ CRNA, Dr. Aysar Al-Bargouthi² MD, Dr. Aidah Alkaissi 3*, PhD
1, An-Najah National University, Faculty of Higher Studies- Nablus-Palestine
2, Palestine Medical Complex, Ramallah, Palestine
3, An-Najah National University-Faculty of Medicine and Health Sciences-Nursing & Midwifery Department-Nablus-Palestine
*Dr. Aidah Alkaissi, An-Najah National University- Faculty of Medicine and Health Sciences- Nursing & Midwifery Department- Nablus-Palestine, PO. Box 7, e- mail [email protected]
Hypotension during spinal anesthesia for cesarean section is secondary to the sympathetic blockade and aorto-caval compression by the uterus and it can be deleterious to both the fetus and the mother. Ephedrine and phenylephrine improve venous return after sympathetic blockade during the spinal block.
Aims of the present study is to compare the efficacy of ephedrine and phenylephrine in the prevention and treatment of maternal hypotension during spinal block, to evaluate the side effects of ephedrine and phenylephrine, and to assess fetal changes as measured by Apgar scores.
Sixty patients, ASA Grade I and II, undergoing spinal anesthesia with bupivacaine and fentanil for cesarean section were randomly divided in two groups to receive prophylactic ephedrine (n = 27, dose = 10 mg) or phenylephrine (n = 28, dose = 80 µg). Mean(SD) age of ephedrine group 30.48± 5.5 vs. phenylephrine group 31.640± 3.3. Hypotension (blood pressure equal or lower than 80% of baseline values) was treated with bolus administration of the vasopressors at 50% of the initial dose. Maternal arterial pressure (BP) and heart rate (HR) were measured every minute by automated oscillometry. Ringer's lactate (RL) solution (20 ml/kg) was infused in 30 minutes before spinal injection for the all participants. Vital signs (bloodpressure, heart rate, and arterial oxygen saturation) were recorded throughout the surgery. Maternal and neonatal perioperativ complications were also controlled and recorded.The incidence of hypotension, reactive hypertension, bradycardia, tachycardia, nausea and vomiting, and Apgar scores on the 1st and 5th minutes were evaluated.
There was an insignificant difference in demographic data between the groups. The mean dose of ephedrine used was 19.81 mg±5.46 and of phenylephrine was 125.71 µg±35.64. Changes in systolic and diastolic pressure were comparable in the two groups. There were significant differences in the incidence of reactive hypertension episodes (group Ephedrine: 48 (14.5%) vs. group Phenylephrine: 26 (7.7%) P > 0.005). There were no differences in the incidence of bradycardia (group Ephedrine: 3(11.1%) vs. group Phenylephrine: 6 (21.4%) P > 0.301), There were significant differences in the incidence of nausea and vomiting (group Ephedrine: 10 (37%) vs. Phenylephrine 3 (10.7%); P>0.018). There were no significant differences in the incidence of hypotension, an incidence of 18(66.7%) in Group Ephedrine and in Group Phenylephrine 17(60.7%) (P < 0.646). Maternal arrhythmias were more common in ephedrine 10(37%) than phenylephrine group 7 (25%) but the difference is not significant P=0.334 as well maternal restlessness was more common in ephedrine 8 (30.8%) than phenylephrine group 3 (10.7%)but insignificant difference P=0.068.
Differences in the Apgar score in the 1st and 5th minute were not observed. Number of patients who required rescue dose in ephedrine group 24 (88.9%) was significantly higher than phenylephrine 20 (71.4%), P 0.005). There are significant differences in the number of rescue does between the two drugs, for phenylephrine, there is only one patient (3.6%) received 3 number of rescue doses, and Ephedrine, there are 9 patients (33.3%) have received 3 number of rescue does, P = 0.033
We conclude from this study that that phenylephrine 80µg had similar vasopressor efficacy to ephedrine 10 mg for preventing or treating maternal hypotension during spinal anaesthesia for elective caesarean delivery and there was no difference in clinical neonatal outcome as measured by Apgar scores. The applicability of the results is limited to healthy women with term fetuses. This study does not support the traditional idea that ephedrine is the preferred choice over phenylephrine for the management of maternal hypotension during spinal anesthesia for elective cesarean delivery in healthy, nonlaboring women. The clinical significance of bradycardia, reactive hypertension and intraoperative nausea and vomiting should not be overlooked. Phenylephrine prior spinal anesthesia is superior to ephedrine in reducing reactive hypertention, nasea, vomiting and requirement of vasopressors rescue medication. The results of the present study support the use of phenylephrine for maintenance of maternal arterial pressure during spinal anaesthesia for elective Caesarean section.
7. Nurse Anesthetic implications
phenylephrine 80µg had similar vasopressor efficacy to ephedrine 10 mg for preventing or treating maternal hypotension during spinal anaesthesia for elective caesarean delivery and there was no difference in clinical neonatal outcome as measured by Apgar scores. In view of maternal complications, the most important and noticeable complication was brief bradycardia (reflex bradycardia), which was transient and only in a few cases (HR<60 per minute) that needed treatment with 0.5 mg intravenous Atropine. Nausea and vomiting that responded rapidly to antiemetic medication was a little high in ephedrine group. None of the observed complications were serious enough to have a significant impact on either the mothers or newborns that use of the Apgar Score.