Phenylephrine infusion for spinal-induced hypotension in elective cesarean delivery: Does preload make a difference?

Area of Science:

• Anesthesiology
• Obstetrics
• Pharmacology

Background:

• Spinal anesthesia for cesarean delivery (CD) carries a high risk of spinal-induced hypotension (SIH).
• Preload fluid administration is a common strategy to mitigate SIH.
• The comparative efficacy of colloid versus crystalloid preloads for SIH prevention in CD patients is not fully established.

Purpose of the Study:

• To investigate whether a colloid preload reduces spinal-induced hypotension (SIH) more effectively than a crystalloid preload in patients undergoing elective cesarean delivery (CD).

Main Methods:

• Eighty-two healthy parturients scheduled for elective CD were randomized into two groups.
• One group received 1500 ml of Lactated Ringer's solution (crystalloid), while the other received 500 ml of 6% hydroxyethyl starch in normal saline (colloid) 30 minutes before spinal anesthesia.
• All patients received a phenylephrine infusion, titrated as needed.

Main Results:

• The incidence of hypotension was not statistically different between the colloid (10.8%) and crystalloid (27.0%) groups (P = 0.12).
• No significant differences were observed in bradycardia, APGAR scores, or nausea and vomiting between the groups.
• The colloid group required significantly less phenylephrine (1077.5 ± 514 mcg) compared to the crystalloid group (1477 ± 591 mcg) (P = 0.003).

Conclusions:

• Preload with hydroxyethyl starch (colloid) before cesarean delivery may offer benefits in preventing spinal-induced hypotension (SIH).
• While not reaching statistical significance for hypotension incidence, the reduced need for vasopressors suggests a potential clinical advantage.