Thay đổi thông khí vùng phổi đo bằng cắt lớp trở kháng điện trong phẫu thuật nội soi cắt đại – trực tràng

Electrical Impedance Tomography (EIT) represents a significant advancement in non-invasive, radiation-free monitoring of regional lung ventilation, offering real-time insights into lung mechanics. Globally, EIT has proven effective in managing critically ill patients with acute respiratory distress syndrome (ARDS) and optimizing mechanical ventilation during various surgical interventions. In Vietnam, EIT has been utilized since 2021, primarily for ARDS cases. However, the comprehensive impact of laparoscopic colorectal surgery—a procedure involving CO2 insufflation and specific patient positioning, known to increase the risk of atelectasis—on regional lung ventilation patterns, as specifically measured by EIT, remains underexplored. This study addresses this critical gap by investigating these dynamic changes to enhance understanding and patient care.

Anesthesiologists, critical care physicians, surgeons specializing in colorectal procedures, and researchers in respiratory physiology and medical monitoring.

This prospective observational study employed Electrical Impedance Tomography (EIT) to meticulously describe the dynamic changes in regional lung ventilation during laparoscopic colorectal surgery under general anesthesia. Conducted at Bach Mai Hospital with 64 patients between November 2024 and August 2025, the methodology involved collecting EIT data at eight distinct time points, spanning from pre-anesthesia induction to the end of surgery, encompassing critical phases such as tracheal intubation, CO2 insufflation, patient positioning, and CO2 desufflation. The research aimed to comprehensively analyze how these interventions impact lung mechanics and ventilation distribution.

Key findings revealed a significant alteration in ventilation patterns. The anterior-to-posterior ventilation ratio, initially >1 at baseline, decreased to <1 from post-intubation until the end of surgery, indicating a consistent shift of ventilation towards the anterior lung regions. Posterior lung ventilation demonstrated a notable reduction, decreasing from 51.57% at baseline to 34.01% at T3 (after CO2 insufflation and position change). Furthermore, a significant redistribution occurred between the right and left lungs, with increased ventilation in the left lung and a corresponding decrease in the right lung compared to baseline, especially pronounced in the head-down right-tilt position, where right lung ventilation dropped to a minimum of 31.47%. Critically, while some recovery was observed post-desufflation, the ventilation patterns did not fully return to preoperative levels.

In conclusion, the study unequivocally demonstrates that endotracheal anesthesia and laparoscopic abdominal surgery markedly alter the regional distribution of lung ventilation, primarily reducing ventilation in dependent lung regions. These insights underscore the crucial role of EIT in real-time monitoring to identify and potentially mitigate ventilation inhomogeneities. The implications are significant for optimizing mechanical ventilation strategies and patient positioning during laparoscopic surgery to improve respiratory outcomes and prevent post-operative pulmonary complications.