Extravascular lung water index measurement in critically ill children does not correlate with a chest x-ray score of pulmonary edema

Abstract

IntroductionExtravascular lung water index (EVLWI) can be measured at the bedside using the transpulmonary thermodilution technique (TPTD). The goal of this study was to compare EVLWI values with a chest x-ray score of pulmonary edema and markers of oxygenation in critically ill children.MethodsThis was a prospective observational study in a pediatric intensive care unit of a university hospital. We included 27 critically ill children with an indication for advanced invasive hemodynamic monitoring. No specific interventions for the purpose of the study were carried out. Measurements included EVLWI and other relevant hemodynamic variables. Blood gas analysis, ventilator parameters, chest x-ray and TPTD measurements were obtained within a three-hour time frame. Two radiologists assessed the chest x-ray and determined a score for pulmonary edema.ResultsA total of 103 measurements from 24 patients were eligible for final analysis. Mean age was two years (range: two months to eight years). Median cardiac index was 4.00 (range: 1.65 to 10.85) l/min/m2. Median EVLWI was 16 (range: 6 to 31) ml/kg. The weighted kappa between the chest x-ray scores of the two radiologists was 0.53. There was no significant correlation between EVLWI or chest x-ray score and the number of ventilator days, severity of illness or markers of oxygenation. There was no correlation between EVLWI and the chest x-ray score. EVLWI was significantly correlated with age and length (r2 of 0.47 and 0.67 respectively).ConclusionsThe extravascular lung water index in critically ill children does not correlate with a chest x-ray score of pulmonary edema, nor with markers of oxygenation.

Advanced Hemodynamic Monitoring in Critically Ill Children

“…Measurement of EVLWI in children or pediatric animal models has revealed higher values compared with adult normal values. 6,20,26,27,62 As a result, the validity of these measurements in children has been questioned. 85 There is still no solid explanation why EVLW values are higher in young children.…”

“…24 The transpulmonary thermodilution technology also offers the measurement of global enddiastolic volume, reflecting preload, and extravascular lung water (EVLW), which reflects pulmonary edema. [25][26][27] For in-depth technical information, see ref 28 . In general, the bedside CO techniques cannot be used in patients with intracardiac and extracardiac shunts.…”

How to Perform Indexing of Extravascular Lung Water

“…Support for our findings is in the pédiatrie literature. On average, children present with lower absolute EVLW but higher weight-indexed values than adults (48)(49)(50)(51). Relationships with age, body height, and weight are described in pédiatrie populations (48,49,52).…”

Extravascular Lung Water and Sepsis

“…Bu yöntemle akciğerin kuru ve ıslak ağırlıkları karşılaştırılarak total akciğer sıvısı belirlenir (9)(10)(11) . Dilüsyon yöntemi 1950'li yıllarda bulunan; dolaşıma indikatör bir maddenin enjeksiyonu ile matematiksel bulguların elde edildiği bir yöntem-dir.…”

“…Söz konusu değerin yaş ve boy bağımlı olduğu vurgulanmış; erişkinlerdeki değerlerin ço-cuklara uygulanamayacağı sonucuna varılmıştır (11) . Bunun tam aksine EVLW'nin özellikle boy ile korelasyon gösterdiği; yaş ve vücut ağırlığı ile bağlantılı olmadığı da ileri sürülmüştür (22) .…”