Novel Obstetric Air Cushion for the Prevention of Hypotension During Spinal Anesthesia for Cesarean Section: A Randomized Controlled Clinical Trial.

Purpose: Intravenous administration of large doses of vasopressors to treat hypotension due to spinal anesthesia can adversely affect the fetus and the mother. We assessed the effect of a novel obstetric air cushion pretreatment on the incidence of hypotension after spinal anesthesia.

Patients and methods: Eighty parturients were randomly assigned to the air cushion or blank control group (Group A or B, respectively). The air cushion was placed in the lumbar area between the lower border of the costal arch and the iliac crest. The primary endpoint was the incidence of hypotension, while the secondary endpoints included norepinephrine dosage, success rate of maternal hypotension management, and adverse reactions like bradycardia.

Results: Hypotension occurred in 50% of the participants in Group A and 75% of those in Group B(P=0.035). Group A (median 4μg, range 0-8μg) required a lower norepinephrine dose than Group B (median 4μg, range 0-12μg; P=0.015). The success rate of hypotension management was significantly higher for Group A at 97.4% than for Group B at 83.3% (P=0.035). Bradycardia was less frequent for Group A than for Group B (10.5% vs 30.6%, P=0.032). Group A also showed a higher umbilical artery blood pH than Group B(P=0.026).

Conclusion: The novel air cushion pretreatment reduces the incidence of hypotension after spinal anesthesia in pregnant women, reduces the dose of single intravenous norepinephrine, improves the success rate of hypotension management, and increases the pH of fetal umbilical artery blood.