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A Prospective Comparison of a Noninvasive Cardiac Output Monitor Versus Esophageal Doppler Monitor for Goal-Directed Fluid Therapy in Colorectal Surgery Patients

Waldron, Nathan H. MD*; Miller, Timothy E. MB ChB, FRCA*; Thacker, Julie K. MD; Manchester, Amy K. MD*; White, William D. MPH*; Nardiello, John MD*; Elgasim, Magdi A. MBBS*; Moon, Richard E. MD, CM, MSc, FRCP (C), FACP, FCCP*; Gan, Tong J. MD, MHS, FRCA, Li Ac*

doi: 10.1213/ANE.0000000000000182
Technology, Computing, and Simulation: Research Report

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.

From the Departments of *Anesthesiology and Surgery, Duke University, Durham, North Carolina.

John Nardiello, MD, is currently affiliated with American Anesthesiology, Duke Raleigh Hospital, Raleigh, North Carolina.

Accepted for publication January 22, 2014.

Funding: Funding for this study was provided in part by Cheetah, Inc., manufacturers of the NICOM device. The first author was supported by a Duke CTSA scholarship program funded by grant number TI1 RR 024126 by the National Institutes of Health as well as the Foundation for Anesthesia Education and Research (FAER) Medical Student Anesthesia Research Fellowship.

Conflict of Interest: See Disclosures at the end of the article.

This report was previously presented, in part, at the 2011 National Predoctoral Meeting on May 12, 2012, in St. Louis, MO, at the 2011 ASA meeting on October 16 and 17 in Chicago, IL, as well as at the 2012 CAS meeting on June 15 to 17 in Quebec City, Quebec, Canada.

Reprints will not be available from the authors.

Address correspondence to Tong J Gan, MD, MHS, FRCA, Li Ac, Department of Anesthesiology, Duke University, Box 3094, Suite 4315DS, Durham, NC 27710. Address e-mail to

© 2014 International Anesthesia Research Society