Normal Values for ELWI and GEDV in Critically Ill Adults
The normal ELWI is 3-7 mL/kg and normal GEDV is 680-800 mL/m² based on measurements in healthy individuals, but critically ill patients frequently exceed these values, particularly septic patients who demonstrate significantly higher values (ELWI ~11 mL/kg, GEDV ~788 mL/m²) compared to surgical patients (ELWI ~7.2 mL/kg, GEDV ~694 mL/m²). 1, 2
Standard Reference Values
- ELWI normal range: 3-7 mL/kg 1, 2
- GEDV normal range: 680-800 mL/m² 2
- These values are derived from healthy individuals and expert opinion 2
Clinical Thresholds for Pathology
Extravascular Lung Water Index (ELWI)
- ELWI >10 mL/kg indicates pulmonary edema 1, 3
- ELWI >15 mL/kg indicates severe pulmonary edema 1
- ELWI >14 mL/kg is associated with significantly increased mortality (87% vs 41%) 4
Pulmonary Vascular Permeability Assessment
- ELWI >10 mL/kg PLUS PVPI >3 suggests ARDS (increased vascular permeability) 1
- ELWI >10 mL/kg PLUS PVPI <2 suggests cardiogenic pulmonary edema (normal vascular permeability) 1
Population-Specific Variations
Septic Patients
- Mean GEDV: 788 mL/m² (95% CI: 762-816) 2
- Mean ELWI: 11.0 mL/kg (95% CI: 9.1-13.0) 2
- GEDV is 94 mL/m² higher than surgical patients 2
- ELWI is 3.3 mL/kg higher than surgical patients 2
Major Surgery Patients
Important Clinical Caveats
The proposed "normal" values from healthy individuals are frequently exceeded in critically ill patients and should not be rigidly applied as therapeutic targets. 2 Published data demonstrate substantial heterogeneity, with different patient populations requiring different therapeutic thresholds 2.
Measurement Considerations
- Values are obtained via transpulmonary thermodilution technique 1, 5
- Single thermodilution correlates well with double-indicator dilution (r=0.96-0.97) 5
- ELWI systematically overestimates at low-normal values and underestimates at values >12 mL/kg when using single thermodilution 5