# The Impact of Intraoperative Position Changes on Hemodynamics and Cardiac Electrophysiological Balance Index in Patients with Severe Obesity Undergoing Laparoscopic Sleeve Gastrectomy

## TL;DR

This study examines how changing patient positions during laparoscopic sleeve gastrectomy affects heart function in severely obese patients.

## Contribution

The study introduces the cardiac electrophysiological balance index (iCEB) as a biomarker to assess autonomic cardiac function during surgical positioning.

## Key findings

- Positional changes during surgery significantly altered hemodynamic parameters and cardiac electrical activity.
- The iCEB index peaked after desufflation in the reverse Trendelenburg position but remained within normal reference ranges.
- Most patients tolerated the hemodynamic changes well with preserved cardiac autonomic regulation.

## Abstract

Pneumoperitoneum and the reverse Trendelenburg (RT) position during laparoscopic sleeve gastrectomy (LSG) can induce autonomic instability and increase the risk of arrhythmias by reducing venous return. This study aimed to evaluate the impact of surgical positioning during LSG on autonomic cardiac function, using hemodynamic parameters and the cardiac electrophysiological balance index (iCEB = QT/QRS) as a biomarker.

This prospective observational study included 66 patients with severe obesity who underwent LSG. Measurements were recorded at five distinct time points, corresponding to specific patient positioning during the procedure: P-baseline (before induction, supine), P1 (after induction, supine), P2 (after pneumoperitoneum, supine), P3 (during pneumoperitoneum, RT), and P4 (after desufflation, RT).

Systolic, diastolic, and mean arterial pressures (SAP, DAP, and MAP) significantly decreased at all positions compared to baseline (p < 0.001 for each). Compared to post-induction (P1), SAP values were substantially higher in the P2 and P4 positions (p < 0.05, p < 0.001, respectively). Heart rate significantly decreased at P1 compared to baseline (p < 0.004) and subsequently increased at P2 and P3 relative to P1 (p < 0.001 and p < 0.009, respectively). A notable increase in iCEB was observed at P4 when compared to P1, P2, and P3 (p < 0.003, p < 0.001, and p < 0.021, respectively). Despite these changes, iCEB values remained within the reference range across all measured positions.

Despite the observed effects of positional changes and pneumoperitoneum on hemodynamic and cardiac electrical parameters during LSG, most patients tolerated these changes well. Crucially, iCEB values remained within the normal reference range throughout the procedure, indicating preserved cardiac autonomic regulation.

The online version contains supplementary material available at 10.1007/s11695-026-08497-5.

• Positional changes during laparoscopic sleeve gastrectomy resulted in significant alterations in hemodynamic parameters and cardiac electrical activity in patients with severe obesity.

• After induction, the cardiac electrophysiological balance index (iCEB) initially demonstrated a significant decrease, then gradually increased, peaking statistically after desufflation in the reverse Trendelenburg position.

• Despite dynamic intraoperative changes, iCEB values consistently remained within the normal reference range (3.14–5.35) throughout the procedure, indicating preserved cardiac autonomic regulation.

The online version contains supplementary material available at 10.1007/s11695-026-08497-5.