Obesity Alters Lung Mechanics in Robotic Surgery

University of Vermont Medical Center

Status: Completed

Conditions: Surgery; Obesity; Anesthesia

Treatments: Other: no intervention

Study type: Observational

Funder types: Other

Identifiers

NCT04329910

M18-0048

Details and patient eligibility

About

Intraoperative lung protective ventilation strategies using standardized tidal volumes based on predicted body weight have proven beneficial, but attempts to standardize positive end expiratory pressure (PEEP) settings have not robustly accounted for body habitus or dynamic surgical conditions. Laparoscopic abdominal surgery in Trendelenburg (head-down) is an increasingly common surgical modality that presents a unique physiological challenge to the pulmonary system. In order to delineate the impact of body habitus, pneumoperitoneum, and surgical positioning on intraoperative pulmonary mechanics we conducted an observational study of patients undergoing robotic assisted laparoscopic abdominal surgery in Trendelenburg position. Using esophageal manometry, we partitioned the mechanical properties of the respiratory system into its lung and chest wall components and evaluated the effects of pneumoperitoneum, surgical position, and body mass index (BMI) on transpulmonary pressures, airway and transpulmonary driving pressures, and lung elastance. We hypothesized that increasing BMI would be associated with evidence of increasing atelectasis, increased driving pressures, and elevated lung elastance and that these changes would be exacerbated by pneumoperitoneum and Trendelenburg positioning.

Enrollment: 99 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Inclusion criteria were presentation for robotic assisted laparoscopic abdominal surgery in the supine position, age ≥ 18 years, and ability to provide informed consent

Exclusion criteria

• Exclusion criteria included intrinsic lung disease, ≥ 20 pack year smoking history, reactive airways disease, home oxygen requirement, inability to provide informed consent, emergent surgery, or esophageal pathology (i.e., strictures, varices, history of esophageal dilatation or surgery).

Trial design

99 participants in 5 patient groups

Lean

Description:

BMI \< 25

Treatment:

Other: no intervention

overweight

Description:

BMI 25 - 29.9

Treatment:

Other: no intervention

class i obesity

Description:

BMI 30 -34.9

Treatment:

Other: no intervention

class ii obesity

Description:

BMI 35 - 39.9

Treatment:

Other: no intervention

class iii obesity

Description:

BMI \>= 40

Treatment:

Other: no intervention