The Impact of Morbid Obesity, Pneumoperitoneum, and Posture on Respiratory System Mechanics and Oxygenation During Laparoscopy

Abstract

Morbid obesity significantly decreases respiratory system compliance and increases inspiratory resistance. Increased body weight, and not altered mechanics of breathing, was associated with worse PaO(2) during laparoscopy.

Anesthesia for restrictive bariatric surgery (gastric bypass not included): laparoscopic vs open procedures

“…Respiratory mechanics were affected by both obesity and pneumoperitoneum but varied little with body position. 20 In our study groups, no patient suffered from severe hypoxemia, excessive hypercarbia and barotrauma. We routinely use periodic manual inflation of the lungs ('sigh') to a peak inspiratory pressure of 40 cmH 2 O every 5-10 min, while holding this pressure for 5 s. This maneuver seems to improve at least temporarily the oxygenation.…”

“…14 Abdominal inflation with CO 2 and head-down position may lead to impaired respiratory mechanics 18,19 and may cause hypoxemia, CO 2 retention and increased peak inspiratory pressures during mechanical ventilation. However, according to Sprung et al, 20 body position did not affect respiratory mechanics during laparoscopy in morbidly obese patients. In their report 20 arterial oxygen tension was adversely affected by increased body weight only.…”

“…However, according to Sprung et al, 20 body position did not affect respiratory mechanics during laparoscopy in morbidly obese patients. In their report 20 arterial oxygen tension was adversely affected by increased body weight only. Respiratory mechanics were affected by both obesity and pneumoperitoneum but varied little with body position.…”

The LMA, laparoscopic surgery and the obese patient — Canvs should

“…The PLMA seems better suited than the LMA-C for such patients. They are more likely to have reduced thoracic compliance, increased inspiratory resistance 13 and are commonly believed to be at greater risk of regurgitation. When well-seated, the PLMA allows for ventilation with higher airway pressures and potentially less gastric insufflation.…”

“…3 Les études sur l'utilisation du ML chez des patients atteints d'obésité et d'obésité morbide sont plus limitées. Chez ces patients, le MLP semble plus approprié que le MLC, car ils sont plus susceptibles de présenter une réduction de compliance thoracique, une augmentation de la résistance inspiratoire 13 et, pense-ton, un accroissement du risque de régurgitation. Lorsqu'il est bien placé, le MLP permet une ventilation à pressions plus élevées des voies aériennes et potentiellement moins d'insufflation gastrique.…”