title: Hypovolemia after traditional preoperative care in patients undergoing colonic surgery is underrepresented in conventional hemodynamic monitoring.
abstract: OBJECTIVE
  Hypovolemia after bowel preparation as well as capnoperitoneum (CP) may compromise hemodynamic function during laparoscopic colonic surgery. A fall in arterial pressure after induction of anesthesia is often answered by generous fluid administration, which might impair "fast-track" rehabilitation. Intraoperative assessment of the needed infusion volume is difficult because of a lack of data regarding the volume status in these patients.
  
  
  METHODS
  Nineteen patients scheduled for laparoscopic colonic surgery after bowel preparation were prospectively monitored using the PULSION COLD Z-021 system and central venous catheter. Intrathoracic blood volume index (ITBVI), mean arterial pressure (MAP), cardiac index (CI), central venous pressure (CVP), and heart rate (HR) were measured after induction of anesthesia (M1), during CP in head-down position with an intraabdominal pressure (IAP) of 20 mmHg (M2) and 12 mmHg (M3).
  
  
  RESULTS
  Although MAP (87 mmHg), HR (64 min(-1)), and CVP (8 mmHg) were within normal ranges at the induction of surgery, ITBVI (834 ml m(-2)), and CI (2.66 l m(-2)) were decreased, indicating a relative hypovolemia. CP with 12 mmHg increased ITBVI (p<0.05) and CI (p<0.01), while an IAP of 20 mmHg reduced CI (p<0.05) compared to 12 mmHg (M3). Mean infusion during the measurements was 1,355 ml.
  
  
  CONCLUSIONS
  Combination of CP with 12 mmHg, head-down position, and infusion of 1,500 ml fluids compensated relative hypovolemia during colonic surgery. With conventional monitoring, intravascular volume status might be underestimated after traditional preoperative care.
authors.affiliation: Department of General, Visceral, Vascular, and Thoracic Surgery, Charité-University Medicine Berlin, Campus Mitte, Schumannstrasse 20/21, 10117, Berlin, Germany. tido.junghans@charite.de
authors.forename: Tido
authors.initials: T
authors.lastname: Junghans
authors.forename: Heiko
authors.initials: H
authors.lastname: Neuss
authors.forename: Michael
authors.initials: M
authors.lastname: Strohauer
authors.forename: Wieland
authors.initials: W
authors.lastname: Raue
authors.forename: Oliver
authors.initials: O
authors.lastname: Haase
authors.forename: Tania
authors.initials: T
authors.lastname: Schink
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schwenk
mesh_terms: D001794:Blood Pressure / Q000502:physiology*; D002302:Cardiac Output / Q000502:physiology; D002496:Central Venous Pressure / Q000502:physiology*; D003082:Colectomy / Q000379:methods*; D003710:Demography; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D020896:Hypovolemia / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D011300:Preoperative Care; D014655:Vascular Resistance / Q000502:physiology*