Association between intra-abdominal pressure and post-spinal hypotension during cesarean delivery: a prospective observational study

Abstract Background Post-spinal hypotension can be exacerbated by increased pressure on the inferior vena cava during cesarean delivery. We examined the relationship between intra-abdominal pressure and post-spinal hypotension. Methods This prospective study included 83 parturients, aged 20–40 years, who underwent elective cesarean delivery in a tertiary level A maternity and child health hospital. Intra-abdominal pressure was measured before the induction of spinal analgesia. A receiver operating characteristic curve was used to determine the optimum cutoff value of intra-abdominal pressure for post-spinal hypotension. Univariable and multivariable logistic regression analyses were performed to explore the association between intra-abdominal pressure or binary classification based on the optimal intra-abdominal pressure cutoff value and hypotension after spinal anesthesia. Results A linear correlation was observed between the decrease in systolic arterial pressure from baseline and intra-abdominal pressure (r = 0.455; P < 0.001). The area under the receiver operating characteristic curve for predicting post-spinal hypotension was 0.92 (95% confidence interval: 0.85–0.99), with an optimal cutoff of 12.5 mm Hg. Intra-abdominal pressure was revealed as an independent risk factor for post-spinal hypotension in the logistic regression analysis. Parturients with an intra-abdominal pressure of ≥ 12.5 mm Hg had 93.73 times the odds of developing post-spinal hypotension than those with an intra-abdominal pressure < 12.5 mm Hg. The occurrence (92.7% vs. 11.9%, P < 0.001) of post-spinal hypotension was different between the two intra-abdominal pressure groups. Conclusions Intra-abdominal pressure was an independent risk factor for post-spinal hypotension during cesarean delivery. A cutoff value of ≥ 12.5 mm Hg could predict subsequent hypotension, while higher intra-abdominal pressure may be associated with a higher incidence of and more severe hypotension before delivery.