title: A prospective comparison of a noninvasive cardiac output monitor versus esophageal Doppler monitor for goal-directed fluid therapy in colorectal surgery patients.
abstract: BACKGROUND
  Goal-directed fluid therapy (GDFT) is associated with improved outcomes after surgery. The esophageal Doppler monitor (EDM) is widely used, but has several limitations. The NICOM, a completely noninvasive cardiac output monitor (Cheetah Medical), may be appropriate for guiding GDFT. No prospective studies have compared the NICOM and the EDM. We hypothesized that the NICOM is not significantly different from the EDM for monitoring during GDFT.
  
  
  METHODS
  One hundred adult patients undergoing elective colorectal surgery participated in this study. Patients in phase I (n = 50) had intraoperative GDFT guided by the EDM while the NICOM was connected, and patients in phase II (n = 50) had intraoperative GDFT guided by the NICOM while the EDM was connected. Each patient's stroke volume was optimized using 250-mL colloid boluses. Agreement between the monitors was assessed, and patient outcomes (postoperative pain, nausea, and return of bowel function), complications (renal, pulmonary, infectious, and wound complications), and length of hospital stay (LOS) were compared.
  
  
  RESULTS
  Using a 10% increase in stroke volume after fluid challenge, agreement between monitors was 60% at 5 minutes, 61% at 10 minutes, and 66% at 15 minutes, with no significant systematic disagreement (McNemar P > 0.05) at any time point. The EDM had significantly more missing data than the NICOM. No clinically significant differences were found in total LOS or other outcomes. The mean LOS was 6.56 ± 4.32 days in phase I and 6.07 ± 2.85 days in phase II, and 95% confidence limits for the difference were -0.96 to +1.95 days (P = 0.5016).
  
  
  CONCLUSIONS
  The NICOM performs similarly to the EDM in guiding GDFT, with no clinically significant differences in outcomes, and offers increased ease of use as well as fewer missing data points. The NICOM may be a viable alternative monitor to guide GDFT.
authors.affiliation: From the Departments of *Anesthesiology and †Surgery, Duke University, Durham, North Carolina.
authors.forename: Nathan H
authors.initials: NH
authors.lastname: Waldron
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Miller
authors.forename: Julie K
authors.initials: JK
authors.lastname: Thacker
authors.forename: Amy K
authors.initials: AK
authors.lastname: Manchester
authors.forename: William D
authors.initials: WD
authors.lastname: White
authors.forename: John
authors.initials: J
authors.lastname: Nardiello
authors.forename: Magdi A
authors.initials: MA
authors.lastname: Elgasim
authors.forename: Richard E
authors.initials: RE
authors.lastname: Moon
authors.forename: Tong J
authors.initials: TJ
authors.lastname: Gan
mesh_terms: D000368:Aged; D000758:Anesthesia / Q000379:methods; D000762:Anesthesia Recovery Period; D002302:Cardiac Output / Q000502:physiology*; D003106:Colon / Q000601:surgery*; D013505:Digestive System Surgical Procedures / Q000379:methods*; D015150:Echocardiography, Doppler; D004947:Esophagus / Q000000981:diagnostic imaging*; D005260:Female; D005440:Fluid Therapy / Q000379:methods*; D006040:Goals; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation* / Q000379:methods*; D010149:Postoperative Pain / Q000188:drug therapy; D011184:Postoperative Period; D011446:Prospective Studies; D012007:Rectum / Q000601:surgery*; D013318:Stroke Volume / Q000502:physiology; D018608:Ultrasonography, Doppler