Thermodilution right ventricular ejection fraction measurements: room temperature versus cold temperature injectate

Area of Science:

• Critical Care Medicine
• Cardiovascular Physiology
• Medical Device Technology

Background:

• Thermodilution is a common method for measuring right ventricular ejection fraction (RVEF).
• The temperature of the injectate (room vs. cold) may influence measurement accuracy.
• Standard protocols often recommend cold injectate, potentially increasing procedure time and cost.

Purpose of the Study:

• To compare the accuracy and reproducibility of RVEF measurements using room temperature versus cold temperature injectate.
• To determine if room temperature injectate is a viable alternative for RVEF assessment in adult surgical intensive care unit (ICU) patients.

Main Methods:

• A prospective clinical study was conducted in an adult surgical ICU.
• Sixty patients requiring pulmonary artery catheterization underwent RVEF measurements.
• Room temperature (23.9°C) and cold (8.0°C) 10 mL injectate thermodilution measurements were alternated and compared.

Main Results:

• No significant difference was found between RVEF measurements using room temperature versus cold temperature injectate (p = .752).
• A high degree of correlation was observed between the two methods (r² = .876, p < .001).
• Bias was -0.39% with a precision of +/- 3.3%, and reproducibility was comparable between groups.

Conclusions:

• Room temperature injectate is a reliable alternative for RVEF measurements in critically ill adult surgical patients.
• Using room temperature injectate can potentially reduce procedure time and healthcare costs in the ICU.
• This finding supports simplifying thermodilution protocols without compromising measurement quality.