Iced versus room temperature injectate for assessment of cardiac output, intrathoracic blood volume, and extravascular lung water by single transpulmonary thermodilution

Abstract

Purpose: To assess the accuracy of iced versus room (RT) temperature single transpulmonary thermodilution (STPD) measurements for cardiac output, intra-thoracic blood, volume and extravascular lung water. Materials and Methods: We studied 15 critically ill patients in a surgical intensive care unit with sepsis/septic shock (n = 8), pancreatitis (n = 2), acute liver failure (n = 2), orthotopic liver transplantation (n = 2) and lung resection (n = 1). All patients were sedated and mechanically ventilated. A 4-French femoral arterial catheter was inserted into each patient and connected to the pulse contour computer system (PiCCO). The pulse contour computer was then consecutively calibrated by triplicate STPD with 20 mL of RT and iced saline solution. The measurements with RT injectate were performed with a special in-line sensor adapted for measurement with RT injectate. All measurements were completed in less than 10 min. Results: A total of 144 measurements were carried out. Linear regression analysis revealed good correlation between the two methods [r = 0.95; r = 0.91 and r = 0.97 for iced v RT cardiac index (CI), intrathoracic blood volume index (ITBVI) and extravascular lung water index (ELWI) respectively]. The bias ± 2 ∗ standard deviation of difference was −0.2 ± 0.7 L/min/m 2 for CI IT v CI RT; −4,9 ± 194 mL/m 2 for ITBVI IT v ITBVI RT and −0.535 ± 1,5 mL/kg for ELWI IT v ELWI RT. CI RT and ELWI RT were measured slightly higher compared to IT injectate ( P < .05). Conclusions: CI, ITBVI, and ELWI assessed by STPD with RT injectate are well correlated with measurements by iced injectates. According to our results room temperature injectates can be used in critically ill patients for assessment of CI, ITBVI and ELWI, which is more convenient for both the patients and medical staff and is also less expensive.