Techniques for preventing hypotension during spinal anaesthesia for caesarean section

Area of Science:

• Obstetrics and Gynecology
• Anesthesiology
• Clinical Trials Research

Background:

• Maternal hypotension is a frequent complication of spinal anesthesia during cesarean sections.
• It can lead to serious risks for both mother and baby, including hypoxia and neurological injury.
• Effective prophylactic interventions are crucial for improving maternal and neonatal outcomes.

Purpose of the Study:

• To evaluate the effectiveness of prophylactic interventions aimed at preventing hypotension after spinal anesthesia for cesarean section.
• To synthesize evidence from randomized controlled trials on various preventative strategies.

Main Methods:

• Systematic review and meta-analysis of 126 randomized controlled trials involving 9565 participants.
• Interventions included intravenous fluids (crystalloids, colloids), pharmacological agents (ephedrine, phenylephrine, ondansetron), and physical methods (lower limb compression).
• Data were extracted and analyzed using GRADE methodology to assess the quality of evidence.

Main Results:

• Crystalloid fluids showed a modest reduction in hypotension compared to no fluids (low-quality evidence).
• Colloids were more effective than crystalloids in preventing hypotension (very low-quality evidence).
• Ondansetron and lower limb compression also demonstrated effectiveness in reducing hypotension, bradycardia, and nausea/vomiting (low to very low-quality evidence).
• Ephedrine and phenylephrine showed no significant difference in preventing hypotension, though ephedrine was associated with lower bradycardia rates.

Conclusions:

• Several interventions, including crystalloids, colloids, ephedrine, phenylephrine, ondansetron, and lower limb compression, can reduce the incidence of hypotension.
• None of the interventions completely eliminated the need for treatment in all women.
• The quality of evidence for most comparisons was low to very low, limiting definitive conclusions and highlighting the need for further high-quality research.