title: Influence of steep Trendelenburg position and CO(2) pneumoperitoneum on cardiovascular, cerebrovascular, and respiratory homeostasis during robotic prostatectomy.
abstract: BACKGROUND
  The steep (40 degrees ) Trendelenburg position optimizes surgical exposure during robotic prostatectomy. The goal of the current study was to investigate the combined effect of this position and CO(2) pneumoperitoneum on cardiovascular, cerebrovascular, and respiratory homeostasis during these procedures.
  
  
  METHODS
  Physiological data were recorded during the whole surgical procedure in 31 consecutive patients who underwent robotic endoscopic radical prostatectomy under general anaesthesia. Heart rate, mean arterial pressure, central venous pressure, Sp(o(2)), Pe'(co(2)), P(Plat), tidal volume, compliance, and minute ventilation were monitored and recorded. Arterial samples were obtained to determine the arterial-to-end-tidal CO(2) tension gradient. Continuous regional cerebral tissue oxygen saturation (Sct(o(2))) was determined by near-infrared spectroscopy.
  
  
  RESULTS
  Although patients were in the Trendelenburg position, all variables investigated remained within a clinically acceptable range. Cerebral perfusion pressure (CPP) decreased from 77 mm Hg at baseline to 71 mm Hg (P=0.07), and Sct(o(2)) increased from 70% to 73% (P<0.001). Pe'(co(2)) increased from 4.12 to 4.79 kPa (P<0.001) and the arterial-to-Pe'(co(2)) tension difference increased from 1.06 kPa in the normal position to a maximum of 1.41 kPa (P<0.001) after 2 h in the Trendelenburg position.
  
  
  CONCLUSIONS
  The combination of the prolonged steep Trendelenburg position and CO(2) pneumoperitoneum was well tolerated. Haemodynamic and pulmonary variables remained within safe limits. Regional cerebral oxygenation was well preserved and CPP remained within the limits between which cerebral blood flow is usually considered to be maintained by cerebral autoregulation.
authors.affiliation: Department of Anesthesiology, University Medical Center Groningen, University of Groningen, The Netherlands. a.kalmar@anest.umcg.nl
authors.forename: A F
authors.initials: AF
authors.lastname: Kalmar
authors.forename: L
authors.initials: L
authors.lastname: Foubert
authors.forename: J F A
authors.initials: JF
authors.lastname: Hendrickx
authors.forename: A
authors.initials: A
authors.lastname: Mottrie
authors.forename: A
authors.initials: A
authors.lastname: Absalom
authors.forename: E P
authors.initials: EP
authors.lastname: Mortier
authors.forename: M M R F
authors.initials: MM
authors.lastname: Struys
mesh_terms: D000368:Aged; D000768:Anesthesia, General; D002245:Carbon Dioxide / Q000097:blood; D004724:Endoscopy / Q000379:methods; D018475:Head-Down Tilt / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology*; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D007427:Intracranial Pressure / Q000502:physiology; D008170:Lung Compliance / Q000502:physiology; D008297:Male; D008875:Middle Aged; D010313:Partial Pressure; D011028:Pneumoperitoneum, Artificial / Q000379:methods*; D011468:Prostatectomy / Q000379:methods*; D012039:Regional Blood Flow / Q000502:physiology; D012371:Robotics / Q000379:methods*; D013990:Tidal Volume / Q000502:physiology
chemical_list: D002245:Carbon Dioxide