Preload or coload for spinal anesthesia for elective Cesarean delivery: a meta-analysis

Area of Science:

• Anesthesiology
• Obstetrics
• Perinatology

Background:

• Maternal hypotension is a frequent complication of spinal anesthesia during Cesarean delivery.
• While fluid loading is recommended, preload administration is often ineffective in preventing hypotension.
• Coloading, administering fluids during anesthesia induction, has shown promise in maintaining cardiac output in non-pregnant patients.

Purpose of the Study:

• To compare the efficacy of fluid coloading versus preload in preventing maternal hypotension during Cesarean delivery.
• To assess the impact of fluid loading timing on neonatal outcomes.

Main Methods:

• A meta-analysis of randomized controlled trials comparing fluid preload and coload strategies.
• Studies were evaluated for quality, and outcomes included hypotension incidence, blood pressure, nausea/vomiting, umbilical cord pH, and Apgar scores.
• Data were analyzed using random effects modeling.

Main Results:

• Eight studies involving 518 patients were analyzed.
• The incidence of hypotension was similar between the coload (59.3%) and preload (62.4%) groups (OR = 0.93; 95% CI 0.54-1.6).
• No significant differences were observed in other maternal or neonatal outcomes.

Conclusions:

• Delaying surgery for fluid preload is unnecessary.
• Maternal hypotension remains common irrespective of the fluid loading strategy.
• Prophylactic or therapeutic vasopressors are frequently required.