Impact of maternal lateral tilt on cardiac output during caesarean section under spinal anaesthesia: a prospective observational study

Background Left uterine displacement (LUD) has been questioned as an effective strategy to prevent aortocaval compression after spinal anesthesia (SA) for cesarean delivery (CD). We tested if LUD has a significant impact on cardiac output (CO) in patients undergoing CD under SA during continuous non-invasive hemodynamic monitoring with Clearsight. Methods Forty-six patients were included in the final analysis. We considered 4 timepoints of 5 min each: T1 = baseline with LUD; T2 = baseline without LUD; T3 = after SA with LUD; T4 = after SA without LUD. LUD was then repositioned for CD. The primary outcome was to assess if CO decreased from T3 to T4 of at least 1.0 L/min. We also compared CO between T1 and T2 and other hemodynamic variables: mean, systolic and diastolic blood pressure (respectively MAP, SAP and DAP), heart rate (HR), stroke volume (SV), stroke volume variation (SVV), pulse pressure variation (PPV), contractility (dP/dt), dynamic arterial elastance (Ea dyn ) at the different timepoints. Data on fetal Apgar scores and umbilical arterial and venous pH were collected. Results CO did not vary from T3 to T4 (CO mean difference -0.02 L/min [95% CI -0.88 to 0.82; P = 1). No significant variation was registered for any variable at any timepoint. Conclusions LUD did not show a significant impact on CO during continuous hemodynamic monitoring after SA for CD. Trial registration (retrospectively registered on 03/12/2021) NCT05143684 .