The influence of extracorporeal circulation on EV1000 monitor hemodynamic parameters at two sites of intravenous cold saline injection

Abstract

Objective: Previous studies have suggested that transpulmonary thermodilution (TPTD) measurements are influenced by extracorporeal circulation methods, such as blood purification. Using pigs, we investigated the effect of extracorporeal circulation on hemodynamic measurements at two sites of cold saline injection.

Methods: Six female outbred pigs were included in the study. A vascular access site was made in the left external jugular vein. Cold saline was injected in the right external jugular vein or the right femoral vein. Hemodynamic monitoring was performed using TPTD (EV1000). Cardiac output (CO), global end-diastolic volume (GEDV), and extravascular lung water (EVLW) values were compared between extracorporeal circulation and no extracorporeal circulation. All data are expressed as median values.

Results: The following data were obtained when cold saline was injected into the jugular vein (circulation on vs. circulation off): CO, 2.7 vs. 2.9 L/min (P = 0.04); GEDV, 403 vs. 438 ml (P = 0.04); and EVLW, 310 vs. 306 ml (P = 0.92). The following data were obtained when cold saline was injected into the femoral vein (circulation on vs. circulation off): CO, 2.6 vs. 2.8 L/min (P = 0.18); GEDV, 497 vs. 500 ml (P = 0.18); and EVLW, 341 vs. 345 ml (P = 0.44).

Conclusions: Extracorporeal circulation has an effect on the accuracy of measurement of TPTD injection through the jugular vein. In contrast, no effect of extracorporeal circulation was observed when the femoral vein was used.