Influence of lower limb pneumatic compression on pulmonary artery temperature: effect on cardiac output measurements.
OBJECTIVE
To characterize the decreases in pulmonary artery temperature that coincide with the inflation cycle of pneumatic calf compression stockings and to examine their effects on the thermodilution measurement of cardiac output.


METHODS
Three-part observational study.


METHODS
University hospital surgical intensive care unit.


METHODS
Postoperative patients with indwelling pulmonary artery catheters.


METHODS
Thermodilution cardiac output measurements with and without pneumatic calf compression.


RESULTS
Phase 1 (n = 18) examined the effects of pneumatic compression on pulmonary artery temperature. There was no effect on pulmonary artery temperature (device off, 37.468+/-0.008 degrees C; device on, 37.458+/-0.014 degrees C), but the difference between the maximum and minimum pulmonary artery temperatures was increased (off, 0.031+/-0.006 degrees C; on, 0.055+/-0.012 degrees C [p < .001]). Phase 2 (n = 12) found that the mean thermodilution cardiac output with 10 mL of cold (0-5 degrees C) injectate was unchanged by pneumatic compression (off, 7.00+/-2.28 L/min; on, 6.89+/-2.22 L/min). However, when the compression devices were operating, the variability between the individual measurements was increased, as reflected by larger coefficients of variation (off, 3.19+/-1.96; on, 8.72+/-6.56 [p < .02]). Similar results were obtained during phase 3 (n = 5), when cardiac output was measured with room temperature Injectate.


CONCLUSIONS
Intermittent pneumatic calf compression increased lower limb venous return, causing acute but transient decreases in pulmonary artery blood temperature. This did not affect the accuracy of thermodilution cardiac output measurements that were made using 10 mL of either cold or room temperature injectate.
Horiuchi
K
K
Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, New York, NY, USA.
Johnson
R
R
Weissman
C
C
D001458:Bandages; D001831:Body Temperature; D002302:Cardiac Output; D002408:Catheters, Indwelling; D003422:Critical Care; D006801:Humans; D007866:Leg; D011184:Postoperative Period; D011651:Pulmonary Artery / Q000502:physiology*; D013815:Thermodilution