Techniques for preventing hypotension during spinal anaesthesia for caesarean section.

Area of Science:

• Obstetrics and Gynecology
• Anesthesiology
• Maternal-Fetal Medicine

Background:

• Maternal hypotension is a frequent complication of spinal anesthesia during cesarean sections.
• It poses risks to both mother and baby, including hypoxia and neurological injury.

Purpose of the Study:

• To evaluate the effectiveness of prophylactic interventions for preventing maternal hypotension after spinal anesthesia for cesarean delivery.

Main Methods:

• Systematic review and meta-analysis of 125 randomized controlled trials involving 9469 women.
• Interventions included intravenous fluids (crystalloids, colloids), pharmacological agents (ephedrine, phenylephrine, ondansetron), and physical methods (lower limb compression, walking).
• Data were extracted and analyzed, with study quality assessed using GRADE criteria.

Main Results:

• Crystalloid infusions reduced 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 showed effectiveness in preventing hypotension, bradycardia, and nausea/vomiting (low to very low-quality evidence).
• Ephedrine reduced bradycardia compared to phenylephrine, with no significant difference in hypotension rates.

Conclusions:

• Prophylactic interventions like crystalloids, colloids, ondansetron, and lower limb compression can decrease maternal hypotension during cesarean sections.
• No intervention completely eliminated the need for hypotension treatment in all women.
• The quality of evidence was generally low to very low, limiting definitive conclusions on rare adverse effects.