Article Text
Abstract
Introduction Extravascular lungwater (EVLW) can be measured at the bedside using the transpulmonary thermodilution method (TPTD), which quantifies the amount of pulmonary edema. This technique has never been validated in conditions of high indexed EVLW levels measured in infants and young children. We compared EVLWTPTD measurements with the transpulmonary double indicator dilution method (TPDD; ice-cold indocyanin green) and post mortem gravimetry.
Methods In eleven newborn lambs pulmonary edema was induced using a surfactant wash-out lavage ALI model. Serial EVLW measurements by TPTD and TPDD were performed at various levels of lung water and the final EVLW values were compared with the post mortem gravimetry results. Data were analyzed using correlation statistics (Spearman’s coefficient of rank correlation (rho)).
Results A total of 25 simultaneous TPTD and TPDD measurements from ten lambs were analyzed with a median EVLWITPDD of 24.0 (IQR 20.7) ml/kg. One lamb died before the measurements were performed. Correlation between EVLWTPTD and EVLWTPDD was r=0.94 (figure 1; p<0.0001, 95%CI 0.87–0.97). Median EVLWGravimetry was 23.9 (IQR9.4) ml/kg. The correlation between the final EVLWTPTD and the EVLWGravimetry was r=0.93 (figure 2; p<0.0002, 95%CI 0.71–0.99).
Conclusions EVLW measurements by TPTD in severe pulmonary edema correlate well with the gold standards.