Healthcare & Clinical Formulas
Murray Lung Injury Score (LIS) & VV-ECMO Referral Threshold (>= 3.0)
Average the 4 ordinal (0–4) Murray Lung Injury Score components—Chest Radiograph Quadrants, PaO2/FiO2 Hypoxemia, PEEP Level, and Respiratory System Compliance—to evaluate > 2.5 Severe ARDS and >= 3.0 VV-ECMO referral criteria.
Why VV-ECMO centers average Murray’s 4 domains instead of looking at P/F alone!
John F. Murray et al. (American Review of Respiratory Disease, 1988) created the 4-domain Lung Injury Score (LIS, 0.00–4.00) by averaging available 0-to-4 component scores across: (1) Chest X-Ray alveolar consolidation quadrants (0 = none, 1–4 quadrants), (2) Hypoxemia PaO_2/FiO_2 (>=300 = 0, 225–299 = 1, 175–224 = 2, 100–174 = 3, <100 = 4), (3) Ventilator PEEP (<=5 = 0, 6–8 = 1, 9–11 = 2, 12–14 = 3, >=15 cmH_2O = 4), and (4) Static Respiratory Compliance (>=80 = 0, 60–79 = 1, 40–59 = 2, 20–39 = 3, <=19 mL/cmH_2O = 4)!
Because Murray divides the sum by the number of available measured components (AVERAGE(B2:B5), allowing unmeasured compliance to be left blank if spontaneous breathing precludes plateau pressure!), LIS stays normalized on 0–4: 0 = No Lung Injury, 0.1–2.5 = Mild-to-Moderate Lung Injury, > 2.5 = Severe ARDS, and >= 3.0 = landmark CESAR trial / ELSO criterion for veno-venous ECMO transfer!
| Murray Lung Injury Score (0.00–4.00) | Component Profile Example | ARDS & ECMO Triage Tier |
|---|---|---|
| 0.00 Points | All 4 Domains = 0 | No Acute Lung Injury (0) |
| 0.25 – 2.50 Points (e.g., [2, 3, 2, 2] -> 2.25) | Moderate Consolidation & PEEP | Mild-to-Moderate Lung Injury (0.1–2.5) |
| 2.75 (>2.5) / >= 3.00 (e.g., [3, 4, 3, 3] -> 3.25) | 4-Quadrant Stiff Lung, P/F <100 | Severe ARDS (>2.5); VV-ECMO Eligible (>=3.0!) |
Murray Composite Lung Injury Score = AVERAGE(B2:B5) (0.00–4.00)
Verifies at least 2 components are recorded and all recorded grades fall inside [0, 4] before returning AVERAGE(B2:B5).
=IF(OR(COUNT(B2:B5) < 2, MIN(B2:B5) < 0, MAX(B2:B5) > 4), "Invalid Murray Component (0-4)", ROUND(AVERAGE(B2:B5), 2))Murray ARDS Severity & CESAR VV-ECMO Referral Classification
Flags LIS >= 3.0 as VV-ECMO Referral Candidate, > 2.5 as Severe ARDS, 0.1–2.5 as Mild-to-Moderate, and 0 as No Lung Injury.
=IF(OR(COUNT(B2:B5) < 2, MIN(B2:B5) < 0, MAX(B2:B5) > 4), "Invalid Murray Component (0-4)", IF(AVERAGE(B2:B5) >= 3, "Severe ARDS: VV-ECMO Referral Threshold (>=3.0)", IF(AVERAGE(B2:B5) > 2.5, "Severe Lung Injury / ARDS (>2.5)", IF(AVERAGE(B2:B5) > 0, "Mild-to-Moderate Lung Injury (0.1-2.5)", "No Lung Injury (0)"))))Try the example
Use the original values or change them to test your understanding.