Comparison of Continuous Infusion of Epinephrine and Phenylephrine on Hemodynamics During Spinal Anesthesia for Cesarean Delivery: A Randomized Controlled Trial

Epinephrine vs. phenylephrine infusion for prophylaxis against maternal hypotension after spinal anesthesia for cesarean delivery: a randomized controlled trial

BACKGROUND

The hemodynamic effects of relatively low-dose epinephrine and phenylephrine infusions during cesarean delivery under spinal anesthesia were compared.

METHODS

This randomized controlled trial included full-term pregnant women who underwent elective cesarean delivery. After spinal anesthesia, participants received either epinephrine (0.03 mcg/kg/min) or phenylephrine (0.4 mcg/kg/min) infusion that continued until 5 min after delivery. The primary outcome was a composite outcome of the occurrence of any of hypotension, hypertension, bradycardia, and/or tachycardia. Neonatal outcomes, including umbilical artery blood gas and Apgar scores, were assessed.

RESULTS

In total, 98 patients in each group were analyzed, and the number of patients with the composite outcome was comparable between the epinephrine and phenylephrine groups (30/98 [31%] vs. 31/98 [32%], respectively; P = 0.877). However, the incidence of hypotension was likely lower in the epinephrine group than in the phenylephrine group (P = 0.066), and the number of hypotensive episodes per patient was lower in the epinephrine group than in the phenylephrine group. On the other hand, the incidence of tachycardia was higher in the epinephrine group than that in the phenylephrine group. The incidence of hypertension was comparable between the two groups and none of the participants developed bradycardia. Neonatal outcomes were comparable between the two groups.

CONCLUSIONS

Epinephrine and phenylephrine infusion produced comparable maternal hemodynamics and neonatal outcomes. Epinephrine was associated with a higher incidence of maternal tachycardia and likely lower incidence of maternal hypotension than phenylephrine. IRB number: MD-245-2022.

CLINICAL TRIAL REGISTRATION

This study was registered on May 31, 2023 at clinicaltrials.gov registry, NCT05881915, URL: https://classic.

CLINICALTRIALS

gov/ct2/show/NCT05881915term=NCT05881915&draw=2&rank=1.

Benefits and Risks of Medications Used in the Management of Hypotension: A Review

This comprehensive literature review addresses the scarcity and limited study of hypotension treatments compared to abundant antihypertensive drugs. Hypotension, categorized as absolute, relative, or orthostatic, has diverse causes. This review explores various treatments, including drugs affecting the sympathetic nervous system, such as midodrine, dihydroergotamine, and ergotamine, which have shown efficacy in managing hypotension. Dopamine agonists/antagonists and other drugs such as ephedrine, norepinephrine, and fludrocortisone are also discussed, each with distinct mechanisms and applications. Additionally, adjunctive agents such as non-steroidal anti-inflammatory agents, caffeine, and monoamine oxidase inhibitors are reviewed for their effects on blood pressure. This review underscores the importance of understanding the efficacy and safety profiles of hypotension treatments to guide healthcare professionals in optimal drug selection and management, emphasizing the need for further research and comparative studies for evidence-based guidelines.

The use of epinephrine infusion for the prevention of spinal hypotension during Caesarean delivery: A randomized controlled dose-finding trial

BACKGROUND

This study aimed to compare three epinephrine doses for the prevention of spinal hypotension during Caesarean delivery.

METHODS

This randomized controlled trial included full-term pregnant women undergoing elective Caesarean delivery under spinal anesthesia. The participants received prophylactic epinephrine infusions at rates of 0.01, 0.02, or 0.03 mcg/kg/min. Spinal hypotension (systolic blood pressure <80% of baseline) was managed with a 9-mg ephedrine bolus. The primary outcome was the incidence of spinal hypotension. Secondary outcomes included total ephedrine requirement, the incidence of severe spinal hypotension, excessive tachycardia and hypertension, and neonatal outcomes.

RESULTS

The final analysis included 271 patients. The incidence of hypotension was lowest in the 0.03 mcg group (11/90 [12%]), followed by the 0.02 mcg (32/91 [35%]) and the 0.01 mcg (55/90 [61%]) groups (p < 0.001). The median ephedrine requirements (quartiles) were also the lowest in the 0.03 mcg group (0 [0-0] mg), followed by the 0.02 mcg (0 [0-9] mg) and the 0.01 mcg (9 [0-18] mg) groups. The incidence of severe hypotension was lower in the 0.03 mcg and 0.02 mcg groups than in the 0.01 mcg group (3/90 [3%], 5/91 [6%], and 15/90 [17%], respectively). The incidences of excessive tachycardia, hypertension, and neonatal outcomes were comparable among the groups.

CONCLUSION

The use of epinephrine to prevent spinal hypotension during Caesarean delivery is feasible and effective. An initial dose of 0.03 mcg/kg/min produced the lowest incidence of hypotension compared to 0.02 mcg/kg/min and 0.01 mcg/kg/min doses. The three doses were comparable in terms of the incidence of tachycardia, hypertension, and neonatal outcomes.

STUDY REGISTRATION

ClinicalTrials.gov Identifier: NCT05279703.

Consensus on the Southeast Asian management of hypotension using vasopressors and adjunct modalities during cesarean section under spinal anesthesia

BACKGROUND AND AIMS

This consensus statement presents a comprehensive and evidence-based set of guidelines that modify the general European or US guidelines for hypotension management with vasopressors during cesarean delivery. It is tailored to the Southeast Asian context in terms of local human and medical resources, health system capacity, and local values and preferences.

METHODS AND RESULTS

These guidelines were prepared using a methodological approach. Two principal sources were used to obtain the evidence: scientific evidence and opinion-based evidence. A team of five anesthesia experts from Vietnam, the Philippines, and Thailand came together to define relevant clinical questions; search for literature-based evidence using the MEDLINE, Scopus, Google Scholar, and Cochrane libraries; evaluate existing guidelines; and contextualize recommendations for the Southeast Asian region. Furthermore, a survey was developed and distributed among 183 practitioners in the captioned countries to gather representative opinions of the medical community and identify best practices for the management of hypotension with vasopressors during cesarean section under spinal anesthesia.

CONCLUSIONS

This consensus statement advocates proactive management of maternal hypotension during cesarean section after spinal anesthesia, which can be detrimental for both the mother and fetus, supports the choice of phenylephrine as a first-line vasopressor and offers a perspective on the use of prefilled syringes in the Southeast Asian region, where factors such as healthcare features, availability, patient safety, and cost should be considered.