Fetal lactic acidosis with epidural anesthesia

Area of Science:

• Anesthesiology
• Obstetrics
• Perinatology

Background:

• Epidural anesthesia is commonly used for cesarean deliveries.
• Maternal hypotension is a known complication of epidural anesthesia.
• The impact of hypotension on fetal acidosis requires further investigation.

Purpose of the Study:

• To determine the incidence of maternal hypotension during epidural anesthesia for cesarean delivery.
• To assess the effects of maternal hypotension and its treatment with ephedrine on fetal acidosis.
• To identify risk factors for hypotension and its consequences.

Main Methods:

• Review of 336 consecutive cesarean deliveries under epidural anesthesia.
• Analysis of blood pressure changes and vasopressor use (ephedrine).
• Comparison of Apgar scores and fetal blood gas analysis (acidosis) between ephedrine-treated and untreated groups.

Main Results:

• 44% of patients experienced significant hypotension (≥20% blood pressure fall or requiring ephedrine).
• 41% of elective repeat cesarean sections required ephedrine for hypotension.
• Fetal acidosis was proportional to hypotension severity and ephedrine dose; severe hypotension (>15 mg ephedrine) showed pronounced metabolic abnormalities.
• Lactic acidosis persisted until delivery despite blood pressure normalization, suggesting intervillous space hypoperfusion.

Conclusions:

• Maternal hypotension is a significant complication of epidural anesthesia during cesarean delivery.
• Fetal acidosis, particularly lactic acidosis, is linked to the severity of maternal hypotension and ephedrine treatment.
• Intervillous space hypoperfusion is the likely cause of fetal lactic acidosis.