Intraoperative Ventilation of Morbidly Obese Patients Guided by Transpulmonary Pressure

Abstract

Patients during laparoscopic bariatric surgery require high levels of PEEP to maintain a positive transpulmonary pressure throughout the respiratory cycle. EIT monitoring allows for non-invasive monitoring of increasing PEEP demand during capnoperitoneum. Individually adjusted PEEP levels did not result in improved postoperative oxygenation.

Clinical Practice Guidelines for the Perioperative Nutrition, Metabolic, and Nonsurgical Support of Patients Undergoing Bariatric Procedures – 2019 Update: Cosponsored by American Association of Clinical Endocrinologists/American College of Endocrinology, The Obesity Society, American Society for Metabolic and Bariatric Surgery, Obesity Medicine Association, and American Society of Anesthesiologists

“…However, PRMs can improve postoperative pain intensity and opioid requirements after SG or RYGB . In a study by Eichler et al , intraoperative noninvasive monitoring using electrical impedance tomography , with increasing positive end‐expiratory pressure demand during capnoperitoneum to maintain positive transpulmonary pressures throughout the respiratory cycle, was associated with improved postoperative oxygenation. In addition, intraoperative transcutaneous CO 2 monitoring has been found to provide a better estimate of arterial CO 2 partial pressure in patients undergoing laparoscopic bariatric surgery than end‐tidal CO 2 partial pressure .…”

Driving Pressure and Transpulmonary Pressure

“…24 Transpulmonary pressure has been used most frequently in the intensive care unit to guide PEEP setting in the most difficult patients, including patients with ARDS and obese patients. 25,[43][44][45] The essential rationale is to adjust PEEP to values assuring a positive end-expiratory transpulmonary pressure (e.g., end-expiratory transpulmonary pressure, 0 to 10 cm H 2 O). Based on the definition of transpulmonary pressure, titration of mechanical ventilation to these values would avoid end-expiratory alveolar collapse.…”

“…45 In the intraoperative setting, transpulmonary pressure has been used to determine optimal PEEP in patients undergoing laparoscopic bariatric surgery. 44 The use of transpulmonary pressure as a correlate of lung stress has limitations. 27 Compared to the simple measurement of driving pressure, esophageal manometry requires additional equipment and training in placement and interpretation, hindering its clinical use.…”

“…45 Measuring esophageal pressure in obese patients can help to determine optimal levels of PEEP and guide lung recruitment. 45 When directly guided by esophageal manometry 44 or indirectly through electrical impedance tomography, 56 PEEP levels to achieve an end-expiratory transpulmonary pressure greater than or equal to 0 cm H 2 O during laparoscopic bariatric surgeries were higher than routinely used PEEP values: 15 to 18 cm H 2 O before abdominal insufflation and 19 to 40 cm H 2 O after insufflation. These numbers are consistent with average supine esophageal pressures of 12.5 ± 3.9 in the obese versus 6.9 ± 3.1 cm H 2 O in controls.…”

Perioperative care of the obese patient

“…A PEEP of 10 cmH 2 O is often used and has been shown to improve respiratory function, particularly when applied after a recruitment manoeuvre. However, higher PEEP levels may be necessary in some obese patients to optimize lung volumes, regional ventilation distribution and oxygenation, and a PEEP of 16–18 cmH 2 O may be more appropriate. Nevertheless, increasing the PEEP may increase the risk of postoperative pulmonary complications if a concomitant rise in airway plateau pressure increases the driving pressure.…”