title: Respiratory gas exchange during robotic-assisted laparoscopic radical prostatectomy.
abstract: OBJECTIVE
  Robotic-assisted laparoscopic prostatectomy requires patients to be secured in a steep Trendelenburg position for several hours. Added to the CO2 pneumoperitoneum that is created, this positioning invariably restricts diaphragmatic and chest wall excursion, which can adversely affect respiratory gas exchange. This study sought to measure the extent of respiratory gas change during this procedure.
  
  
  METHODS
  Retrospective, institutional review board approved.
  
  
  METHODS
  Operating room.
  
  
  METHODS
  N = 186 males, American Society of Anesthesiologists 2-3, with prostatic carcinoma undergoing robotic-assisted laparoscopic radical prostatectomy.
  
  
  METHODS
  Arterial blood gases and noninvasive respiratory measurements were recorded for those patients (n = 32) in whom a radial arterial catheter had been inserted intraoperatively, specifically timed to different phases of the procedure: supine lithotomy, steep Trendelenburg, and return to supine. Ventilatory parameters were standardized.
  
  
  METHODS
  Systemic blood pressure, heart rate, respiratory rate, Pao2, Paco2, oxygen saturation as measured by pulse oximetry, and end-tidal carbon dioxide pressure.
  
  
  RESULTS
  Although no patients developed perioperative respiratory complications, the Pao2 invariably fell (395 vs 316 mm Hg; P = .001) while the patients were in steep Trendelenburg, and the Paco2-end-tidal carbon dioxide pressure rose (10.0 vs 13.4 mm Hg; P < .0001). Upon return to supine, patients' respiratory measurements promptly returned to within 15% of baseline. Subgroup analysis for high-BMI vs low-BMI patients as well as for patients with pulmonary disease and/or a smoking history showed similar individual effects and only small, although significant, respiratory gas exchange aberrations.
  
  
  CONCLUSIONS
  Positioning patients with a CO2 pneumoperitoneum in steep Trendelenburg for several hours imposes restriction of diaphragmatic and chest wall movement sufficient for respiratory gas exchange to be adversely affected. Return of function to within 15% of baseline occurred within minutes after return to supine and release of the CO2 pneumoperitoneum. No patients during the study period developed pulmonary complications that required alteration in their level of care.
authors.affiliation: Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY, USA. Electronic address: plebowit@montefiore.org.
authors.forename: Philip
authors.initials: P
authors.lastname: Lebowitz
authors.affiliation: Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY, USA. Electronic address: adam.yedlin@gmail.com.
authors.forename: Adam
authors.initials: A
authors.lastname: Yedlin
authors.affiliation: Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY, USA. Electronic address: arihakimi@gmail.com.
authors.forename: A Ari
authors.initials: AA
authors.lastname: Hakimi
authors.affiliation: Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY, USA. Electronic address: cwildonbb@aol.com.
authors.forename: Christopher
authors.initials: C
authors.lastname: Bryan-Brown
authors.affiliation: Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY, USA. Electronic address: mrichard@montefiore.org.
authors.forename: Mahesan
authors.initials: M
authors.lastname: Richards
authors.affiliation: Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY, USA. Electronic address: rghavami@montefiore.org.
authors.forename: Reza
authors.initials: R
authors.lastname: Ghavamian
mesh_terms: D000368:Aged; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood; D018475:Head-Down Tilt / Q000009:adverse effects; D006439:Hemodynamics; D006801:Humans; D010535:Laparoscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D011468:Prostatectomy / Q000379:methods*; D011471:Prostatic Neoplasms / Q000601:surgery; D011659:Pulmonary Gas Exchange; D015656:Respiratory Mechanics; D012189:Retrospective Studies; D012371:Robotics; D016683:Supine Position
chemical_list: D002245:Carbon Dioxide
keywords: Complications during recovery; Laparoscopic prostatectomy; Pulmonary shunting; Respiratory gas effects; Total respiratory compliance; Ventilation/perfusion mismatching