[Comparison of single-indicator thermodilution versus gravimetric measurement in determination of extra-vascular lung water in dogs with acute respiratory distress syndrome].
OBJECTIVE
To compare the measurement of extra-vascular lung water (EVLW) by a single-indicator dilution technique and measurement obtained by gravimetry in different types of acute respiratory distress syndrome (ARDS).


METHODS
Thirty-three dogs were randomly assigned to three groups: control group, oleic acid group and hydrochloric acid group. ARDS was reproduced by either intravenous injection of oleic acid or intratracheal instillation of hydrochloric acid. EVLW was measured before ARDS, at the onset of ARDS and 10 hours after ARDS by a single indicator dilution technique. Ten hours after ARDS, dogs were sacrificed and then EVLW was quantitated by a gravimetric measurement (golden standard). Hemodynamics and pulmonary gas exchange were determined.


RESULTS
There was a close positive correlation (r=0.8820, P<0.05) between single indicator dilution and gravimetric measurements. However, the measurement with the single indicator dilution was consistently higher than the gravimetric measurement. In the control group, there was a positive correlation (r=0.9870, P<0.05) between the values of EVLW as measured by single indicator dilution and by gravimetric measurements. In the oleic acid group, there was also a significant correlation (r=0.9360, P<0.05) between the values of EVLW as measured by single indicator dilution and by gravimetric measurements. In the hydrochloric acid group, correlation (r=0.7950, P<0.05) was also found between EVLW as measured by the two methods. However, the correlation found was lower in the hydrochloric acid group than those in other two groups. Hydrochloric acid instillation resulted in a significant increase in shunting and the partial pressure of carbon dioxide in artery (PaCO(2)) compared with oleic acid group at 10 hours after ARDS.


CONCLUSIONS
The results of measuring EVLW using single indicator dilution measurement are closely related with those of gravimetric measurement in ARDS, however, the correlations varies with the methods of reproduction of ARDS.
Shen
Ju-fang
JF
Department of Critical Care Medicine, Zhong-da Hospital and School of Clinical Medicine, Southeast University, Nanjing 210009, Jiangsu, China. Shenjufang2003@yahoo.com.cn
Qiu
Hai-bo
HB
Yang
Yi
Y
Liu
Song-qiao
SQ
Chen
Yong-ming
YM
Li
Jia-qiong
JQ
Wu
Bin
B
Ding
Hui-min
HM
D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D015633:Extravascular Lung Water / Q000378:metabolism*; D005260:Female; D006851:Hydrochloric Acid / Q000008:administration & dosage; D008297:Male; D019301:Oleic Acid / Q000008:administration & dosage; D011897:Random Allocation; D012128:Respiratory Distress Syndrome / Q000139:chemically induced / Q000175:diagnosis* / Q000378:metabolism; D012129:Respiratory Function Tests / Q000379:methods*; D012680:Sensitivity and Specificity; D013815:Thermodilution / Q000379:methods*
D019301:Oleic Acid; D006851:Hydrochloric Acid