The Importance of Extravascular Lung Water Measurement in Major Surgeries

The incidence of postoperative pulmonary complications varies between 1-23 % and these complications can cause serious mortality. Measurement of extravascular lung water (EVLW) is beneficial not only for the prevention of complications but also in weaning, fluid management and monitorization of response to pharmacological interventions. EVLW consists of interstitial, intracellular, alveolar and lymphatic fluid in lungs except for pulmonary vasculature. Its normal range is 3-7 m/kg in healthy adults, values greater than 10 ml/kg point to pulmonary edema. Although the gold standard for measurement of EVLW is the gravimetric method, due to the fact it can only be applied postmortem, measurement methods by using ultrasonography and transpulmonary thermodilution have been developed. EVLW measurement can be affected by renal replacement therapy, extracorporeal membrane oxygenation (ECMO), pleural effusions and high PEEP. New research focusing on the effect of EVLW measurement on postoperative hemodynamic management is necessary in the future.