Effect of injectate temperature and volume on measurement of thermodilution cardiac output values in surgical intensive care patients

Abstract

The standard thermodilution methoq of measuring cardiac output (CO) at the bedside poses several problems: 1)- It exposes selected· patients. (pediatric and cardiac-compromised) to the risk of volume overload. 2) The use of -iced temperature injectate is more expensive, time-consuming and cumbersome. Th~ purpose.of this study was to compare the effects of two dtffering temperature ranges and volumes of injectate on co measurements. The null hypotheses were: 1) There will be no differences in the CO values obtained with room temperature (RT) injectate (21-25°C) and icedtemperature (IT) injectate (0-5°C)~ 2) There will be no differences in the co values obtained with reduced vo.lume (EV) of injectate (3 cc) and standard volume of ·injectate (5 . cc) . Four sets of co measurements were collected from a nonprobability sample of 23 adult males and females in the surgical intensive care unit. Results were analyzed by Pearson's correlation coefficients and ANOVA. No significant· differences were found for temperature (E = .246, 2 = .625), volume (E = .111, 2 = .742) or interaction of temperature and volume (E = .120, 2 = .284). Results suggest that RT and RV injectate can be employed to accurately measure co by thermodilution.