Estimation of extravascular lung water using the transpulmonary ultrasound dilution (TPUD) method: a validation study in neonatal XXXX .

@entity1 @entity742 @entity1576 @entity3126
UNASSIGNED: Increased extravascular lung water (EVLW) may contribute to @entity1576 in neonates. Accurate measurement of EVLW in these @entity1 is limited due to the lack of bedside methods. The aim of this pilot study was to investigate the reliability of the transpulmonary ultrasound dilution (TPUD) technique as a possible method for estimating EVLW in a neonatal animal model. @entity3126 was induced in 11 @entity742 by repeated surfactant lavages. In between the lavages, EVLW indexed by bodyweight was estimated by TPUD (EVLWItpud) and transpulmonary dye dilution (EVLWItpdd) (n  =  22). Final EVLWItpud measurements were also compared with EVLWI estimations by gold standard post mortem gravimetry (EVLWIgrav) (n  =  6). EVLWI was also measured in two additional @entity742 without @entity3126 . Bland-Altman plots showed a mean bias between EVLWItpud and EVLWItpdd of -3.4  mL/kg (LOA      25.8  mL/kg) and between EVLWItpud and EVLWIgrav of 1.7  mL/kg (LOA      8.3  mL/kg). The percentage errors were 109 and 43  % respectively. The correlation between changes in EVLW measured by TPUD and TPDD was r(2)  =  0.22. Agreement between EVLWI measurements by TPUD and TPDD was low. Trending ability to detect changes between these two methods in EVLWI was questionable. The accuracy of EVLWItpud was good compared to the gold standard gravimetric method but the TPUD lacked precision in its current prototype. Based on these limited data, we believe that TPUD has potential for future use to estimate EVLW after adaptation of the algorithm. Larger studies are needed to support our findings.
