Electrical Impedance Tomography during Abdominal Laparoscopic Surgery: A Physiological Pilot Study.

Area of Science:

• Anesthesiology
• Respiratory Physiology
• Medical Engineering

Background:

• General anesthesia and pneumoperitoneum in laparoscopic surgery can cause atelectasis and impair oxygenation.
• Fixed positive end-expiratory pressure (PEEP) is often used despite varying respiratory mechanics.
• Personalized PEEP, guided by real-time monitoring, may optimize outcomes.

Purpose of the Study:

• To investigate if PEEP titration guided by electrical impedance tomography (EIT) improves oxygenation and respiratory system compliance.
• To evaluate a personalized approach to PEEP in lung-healthy patients undergoing abdominal laparoscopic surgery.

Main Methods:

• Prospective study of 12 patients undergoing abdominal laparoscopic surgery.
• Utilized EIT (Timpel Enlight 1800) with integrated pneumotachograph and spirometer.
• Recorded gas exchange, respiratory mechanics, and hemodynamics at five intraoperative time points.

Main Results:

• A mean PEEP of 8 cmH2O, guided by EIT after a recruitment maneuver, optimized compliance (58.4 ± 5.43 mL/cmH2O) with minimal lung collapse (10%).
• Pneumoperitoneum worsened respiratory mechanics, which improved significantly after recruitment maneuver and EIT-guided PEEP.
• PaO2 increased from 78.1 ± 9.49 mmHg to 188 ± 66.7 mmHg (p < 0.01).

Conclusions:

• EIT serves as a valuable non-invasive monitor for intraoperative lung assessment.
• EIT facilitates identification of optimal PEEP levels, enhancing ventilation strategies during laparoscopic surgery.
• Personalized PEEP guided by EIT improves gas exchange and respiratory mechanics.