2001 OPEN FORUM Abstracts
Comparisonof Continuous Cardiac Output (CCO) to Bolus Thermal Dilution Cardiac Output(TDCO) Using the Edwards Lifesciences Vigilance Monitor
Mark Siobal BS RRT,Richard Kallet MS RRT, Julin Tang MD, Respiratory Care Services, SanFrancisco General Hospital, UCSF Department of Anesthesia.
Background: TheVigilance Monitor measures CCO by introducing small pulses of energy to a thermalfilament equipped pulmonary artery catheter while recording blood temperature.Cardiac output is calculated using the conservation of heat equation. CCO isdisplayed continuously as a running average of 5 - 10 minute intervals. CCOvalues are calculated as often as every 30 ? 60 seconds. The monitor also canbe used to perform traditional TDCO. We compared CCO to the TDCO method usingthe Vigilance monitor in medical-surgical ICU patients.
Method: TDCO was comparedto: CCO 5 to 10 minute running average (CCOave), CCO immediately pre TDCO (CCOpre),and CCO immediately post TDCO (CCOpost). A total of 111 comparisons were donein 16 patients. TDCO was performed every 4 - 6 hours. A 10 cc room temperatureinjectate solution was used. Indicator solution injection using standard techniquewas timed at end inspiration with the patient in a supine or semi fowlers position.Three TDCO determinations (within ± 0.5 L/min) were averaged and compared toCCO values. Results were analyzed using simple regression. Differences wereexamined using the Bland-Altman method.
Results: The mean TDCO, CCOave,CCOpre, and CCOpost were 5.9, 6.2, 6.3, and 6.3 L/min respectively. Regressionanalysis shows a very high correlation between TDCO vs CCOave, TDCO vs CCOpre,and TDCO and CCOpost (R = .92, .94, and .95 respectively, p <.0001). Themean bias and precision between TDCO and all CCO data sets was ? 0.4 ± 1.0 L/min.
Conclusion: Our data showsthat CCO monitoring using the Vigilance monitor is a reliable alternativeto intermittent TDCO determinations.