The effect of prophylactic phenylephrine and ephedrine infusions on umbilical artery blood pH in women with preeclampsia undergoing cesarean delivery with spinal anesthesia

A randomized, double-blind trial

Nicole Higgins, Paul C. Fitzgerald, Dominique Van Dyk, Robert A. Dyer, Natalie Rodriguez, Robert J. McCarthy*, Cynthia A. Wong

*Corresponding author for this work

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

BACKGROUND: Spinal anesthesia for cesarean delivery is associated with a high incidence of hypotension. Phenylephrine results in higher umbilical artery pH than ephedrine when used to prevent or treat hypotension in healthy women. We hypothesized that phenylephrine compared to ephedrine would result in higher umbilical artery pH in women with preeclampsia undergoing cesarean delivery with spinal anesthesia. METHODS: This study was a randomized double-blind clinical trial. Nonlaboring women with preeclampsia scheduled for cesarean delivery with spinal anesthesia at Prentice Women’s Hospital of Northwestern Medicine were randomized to receive prophylactic infusions of phenylephrine or ephedrine titrated to maintain systolic blood pressure >80% of baseline. Spinal anesthesia consisted of hyperbaric 0.75% bupivacaine 12 mg, fentanyl 15 µg, and morphine 150 µg. The primary outcome was umbilical arterial blood pH and the secondary outcome was umbilical artery base excess. RESULTS: One hundred ten women were enrolled in the study and 54 per group were included in the analysis. There were 74 and 72 infants delivered in the ephedrine and phenylephrine groups, respectively. The phenylephrine:ephedrine ratio for umbilical artery pH was 1.002 (95% confidence interval [CI], 0.997–1.007). Mean [standard deviation] umbilical artery pH was not different between the ephedrine 7.20 [0.10] and phenylephrine 7.22 [0.07] groups (mean difference −0.02, 95% CI of the difference −0.06 to 0.07; P = .38). Median (first, third quartiles) umbilical artery base excess was −3.4 mEq/L (−5.7 to −2.0 mEq/L) in the ephedrine group and −2.8 mEq/L (−4.6 to −2.2mEq/L) in the phenylephrine group (difference −0.6 mEq/L, 95% CI of the difference −1.6 to 0.3 mEq/L; P = .10). When adjusted for gestational age and infant gender, umbilical artery pH did not differ between groups. There were also no differences in the umbilical artery pH stratified by magnesium therapy or by the severity of preeclampsia. CONCLUSIONS: We were unable to demonstrate a beneficial effect of phenylephrine on umbilical artery pH compared with ephedrine. Our findings suggest that phenylephrine may not have a clinically important advantage compared with ephedrine with regard to improved neonatal acid-base status when used to prevent spinal anesthesia–induced hypotension in women with preeclampsia undergoing cesarean delivery.

Original languageEnglish (US)
Pages (from-to)1999-2006
Number of pages8
JournalAnesthesia and analgesia
Volume126
Issue number6
DOIs
StatePublished - Jun 1 2018

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Ephedrine
Umbilical Arteries
Spinal Anesthesia
Phenylephrine
Pre-Eclampsia
Hypotension
Confidence Intervals
Blood Pressure
Hospital Medicine
Umbilicus
Bupivacaine
Fentanyl
Magnesium
Morphine
Gestational Age
Clinical Trials
Acids

ASJC Scopus subject areas

  • Anesthesiology and Pain Medicine

Cite this

Higgins, Nicole ; Fitzgerald, Paul C. ; Van Dyk, Dominique ; Dyer, Robert A. ; Rodriguez, Natalie ; McCarthy, Robert J. ; Wong, Cynthia A. / The effect of prophylactic phenylephrine and ephedrine infusions on umbilical artery blood pH in women with preeclampsia undergoing cesarean delivery with spinal anesthesia : A randomized, double-blind trial. In: Anesthesia and analgesia. 2018 ; Vol. 126, No. 6. pp. 1999-2006.
@article{ec100da3c1f34d449eaad4686f264349,
title = "The effect of prophylactic phenylephrine and ephedrine infusions on umbilical artery blood pH in women with preeclampsia undergoing cesarean delivery with spinal anesthesia: A randomized, double-blind trial",
abstract = "BACKGROUND: Spinal anesthesia for cesarean delivery is associated with a high incidence of hypotension. Phenylephrine results in higher umbilical artery pH than ephedrine when used to prevent or treat hypotension in healthy women. We hypothesized that phenylephrine compared to ephedrine would result in higher umbilical artery pH in women with preeclampsia undergoing cesarean delivery with spinal anesthesia. METHODS: This study was a randomized double-blind clinical trial. Nonlaboring women with preeclampsia scheduled for cesarean delivery with spinal anesthesia at Prentice Women’s Hospital of Northwestern Medicine were randomized to receive prophylactic infusions of phenylephrine or ephedrine titrated to maintain systolic blood pressure >80{\%} of baseline. Spinal anesthesia consisted of hyperbaric 0.75{\%} bupivacaine 12 mg, fentanyl 15 µg, and morphine 150 µg. The primary outcome was umbilical arterial blood pH and the secondary outcome was umbilical artery base excess. RESULTS: One hundred ten women were enrolled in the study and 54 per group were included in the analysis. There were 74 and 72 infants delivered in the ephedrine and phenylephrine groups, respectively. The phenylephrine:ephedrine ratio for umbilical artery pH was 1.002 (95{\%} confidence interval [CI], 0.997–1.007). Mean [standard deviation] umbilical artery pH was not different between the ephedrine 7.20 [0.10] and phenylephrine 7.22 [0.07] groups (mean difference −0.02, 95{\%} CI of the difference −0.06 to 0.07; P = .38). Median (first, third quartiles) umbilical artery base excess was −3.4 mEq/L (−5.7 to −2.0 mEq/L) in the ephedrine group and −2.8 mEq/L (−4.6 to −2.2mEq/L) in the phenylephrine group (difference −0.6 mEq/L, 95{\%} CI of the difference −1.6 to 0.3 mEq/L; P = .10). When adjusted for gestational age and infant gender, umbilical artery pH did not differ between groups. There were also no differences in the umbilical artery pH stratified by magnesium therapy or by the severity of preeclampsia. CONCLUSIONS: We were unable to demonstrate a beneficial effect of phenylephrine on umbilical artery pH compared with ephedrine. Our findings suggest that phenylephrine may not have a clinically important advantage compared with ephedrine with regard to improved neonatal acid-base status when used to prevent spinal anesthesia–induced hypotension in women with preeclampsia undergoing cesarean delivery.",
author = "Nicole Higgins and Fitzgerald, {Paul C.} and {Van Dyk}, Dominique and Dyer, {Robert A.} and Natalie Rodriguez and McCarthy, {Robert J.} and Wong, {Cynthia A.}",
year = "2018",
month = "6",
day = "1",
doi = "10.1213/ANE.0000000000002524",
language = "English (US)",
volume = "126",
pages = "1999--2006",
journal = "Anesthesia and Analgesia",
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}

The effect of prophylactic phenylephrine and ephedrine infusions on umbilical artery blood pH in women with preeclampsia undergoing cesarean delivery with spinal anesthesia : A randomized, double-blind trial. / Higgins, Nicole; Fitzgerald, Paul C.; Van Dyk, Dominique; Dyer, Robert A.; Rodriguez, Natalie; McCarthy, Robert J.; Wong, Cynthia A.

In: Anesthesia and analgesia, Vol. 126, No. 6, 01.06.2018, p. 1999-2006.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The effect of prophylactic phenylephrine and ephedrine infusions on umbilical artery blood pH in women with preeclampsia undergoing cesarean delivery with spinal anesthesia

T2 - A randomized, double-blind trial

AU - Higgins, Nicole

AU - Fitzgerald, Paul C.

AU - Van Dyk, Dominique

AU - Dyer, Robert A.

AU - Rodriguez, Natalie

AU - McCarthy, Robert J.

AU - Wong, Cynthia A.

PY - 2018/6/1

Y1 - 2018/6/1

N2 - BACKGROUND: Spinal anesthesia for cesarean delivery is associated with a high incidence of hypotension. Phenylephrine results in higher umbilical artery pH than ephedrine when used to prevent or treat hypotension in healthy women. We hypothesized that phenylephrine compared to ephedrine would result in higher umbilical artery pH in women with preeclampsia undergoing cesarean delivery with spinal anesthesia. METHODS: This study was a randomized double-blind clinical trial. Nonlaboring women with preeclampsia scheduled for cesarean delivery with spinal anesthesia at Prentice Women’s Hospital of Northwestern Medicine were randomized to receive prophylactic infusions of phenylephrine or ephedrine titrated to maintain systolic blood pressure >80% of baseline. Spinal anesthesia consisted of hyperbaric 0.75% bupivacaine 12 mg, fentanyl 15 µg, and morphine 150 µg. The primary outcome was umbilical arterial blood pH and the secondary outcome was umbilical artery base excess. RESULTS: One hundred ten women were enrolled in the study and 54 per group were included in the analysis. There were 74 and 72 infants delivered in the ephedrine and phenylephrine groups, respectively. The phenylephrine:ephedrine ratio for umbilical artery pH was 1.002 (95% confidence interval [CI], 0.997–1.007). Mean [standard deviation] umbilical artery pH was not different between the ephedrine 7.20 [0.10] and phenylephrine 7.22 [0.07] groups (mean difference −0.02, 95% CI of the difference −0.06 to 0.07; P = .38). Median (first, third quartiles) umbilical artery base excess was −3.4 mEq/L (−5.7 to −2.0 mEq/L) in the ephedrine group and −2.8 mEq/L (−4.6 to −2.2mEq/L) in the phenylephrine group (difference −0.6 mEq/L, 95% CI of the difference −1.6 to 0.3 mEq/L; P = .10). When adjusted for gestational age and infant gender, umbilical artery pH did not differ between groups. There were also no differences in the umbilical artery pH stratified by magnesium therapy or by the severity of preeclampsia. CONCLUSIONS: We were unable to demonstrate a beneficial effect of phenylephrine on umbilical artery pH compared with ephedrine. Our findings suggest that phenylephrine may not have a clinically important advantage compared with ephedrine with regard to improved neonatal acid-base status when used to prevent spinal anesthesia–induced hypotension in women with preeclampsia undergoing cesarean delivery.

AB - BACKGROUND: Spinal anesthesia for cesarean delivery is associated with a high incidence of hypotension. Phenylephrine results in higher umbilical artery pH than ephedrine when used to prevent or treat hypotension in healthy women. We hypothesized that phenylephrine compared to ephedrine would result in higher umbilical artery pH in women with preeclampsia undergoing cesarean delivery with spinal anesthesia. METHODS: This study was a randomized double-blind clinical trial. Nonlaboring women with preeclampsia scheduled for cesarean delivery with spinal anesthesia at Prentice Women’s Hospital of Northwestern Medicine were randomized to receive prophylactic infusions of phenylephrine or ephedrine titrated to maintain systolic blood pressure >80% of baseline. Spinal anesthesia consisted of hyperbaric 0.75% bupivacaine 12 mg, fentanyl 15 µg, and morphine 150 µg. The primary outcome was umbilical arterial blood pH and the secondary outcome was umbilical artery base excess. RESULTS: One hundred ten women were enrolled in the study and 54 per group were included in the analysis. There were 74 and 72 infants delivered in the ephedrine and phenylephrine groups, respectively. The phenylephrine:ephedrine ratio for umbilical artery pH was 1.002 (95% confidence interval [CI], 0.997–1.007). Mean [standard deviation] umbilical artery pH was not different between the ephedrine 7.20 [0.10] and phenylephrine 7.22 [0.07] groups (mean difference −0.02, 95% CI of the difference −0.06 to 0.07; P = .38). Median (first, third quartiles) umbilical artery base excess was −3.4 mEq/L (−5.7 to −2.0 mEq/L) in the ephedrine group and −2.8 mEq/L (−4.6 to −2.2mEq/L) in the phenylephrine group (difference −0.6 mEq/L, 95% CI of the difference −1.6 to 0.3 mEq/L; P = .10). When adjusted for gestational age and infant gender, umbilical artery pH did not differ between groups. There were also no differences in the umbilical artery pH stratified by magnesium therapy or by the severity of preeclampsia. CONCLUSIONS: We were unable to demonstrate a beneficial effect of phenylephrine on umbilical artery pH compared with ephedrine. Our findings suggest that phenylephrine may not have a clinically important advantage compared with ephedrine with regard to improved neonatal acid-base status when used to prevent spinal anesthesia–induced hypotension in women with preeclampsia undergoing cesarean delivery.

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DO - 10.1213/ANE.0000000000002524

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