cliot (version 1.0.0)

murray_lung_injury_score: Murray Score for Acute Lung Injury

Description

Calculates the Murray Lung Injury Score (LIS) to assess the severity of Acute Respiratory Distress Syndrome (ARDS). The score averages four components: Hypoxemia (PaO2/FiO2), PEEP, Respiratory Compliance, and Chest X-ray infiltration.

Usage

murray_lung_injury_score(pao2_fio2_ratio, peep, respiratory_compliance,
                         cxr_quadrants)

Value

A list containing:

Murray_Score

The calculated Lung Injury Score (average of the 4 components, Range 0-4).

Severity_Assessment

Interpretation (No Injury = 0, Mild-Moderate 0.1-2.5, Severe > 2.5).

Subscores

Individual points assigned to each component.

Arguments

pao2_fio2_ratio

Numeric. Ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2). >=300: 0 pts. 225-299: 1 pt. 175-224: 2 pts. 100-174: 3 pts. <100: 4 pts.

peep

Numeric. Positive End-Expiratory Pressure (cmH2O). <=5: 0 pts. 6-8: 1 pt. 9-11: 2 pts. 12-14: 3 pts. >=15: 4 pts.

respiratory_compliance

Numeric. Respiratory system compliance (mL/cmH2O). Typically calculated as Tidal Volume / (Plateau Pressure - PEEP). >=80: 0 pts. 60-79: 1 pt. 40-59: 2 pts. 20-39: 3 pts. <=19: 4 pts.

cxr_quadrants

Numeric (0-4). Number of quadrants showing alveolar consolidation on Chest X-ray. 0: 0 pts. 1: 1 pt. 2: 2 pts. 3: 3 pts. 4: 4 pts.

References

Murray JF, Matthay MA, Luce JM, Flick MR. An expanded definition of the adult respiratory distress syndrome. Am Rev Respir Dis. 1988;138(3):720-723. doi:10.1164/ajrccm/138.3.720

Examples

# Example 1: Severe ARDS
# PF 80 (4 pts), PEEP 16 (4 pts), Compliance 18 (4 pts), CXR 4 quads (4 pts)
# Average = 16 / 4 = 4
murray_lung_injury_score(80, 16, 18, 4)

# Example 2: Mild Injury
# PF 250 (1 pt), PEEP 8 (1 pt), Compliance 50 (2 pts), CXR 1 quad (1 pt)
# Average = 5 / 4 = 1.25
murray_lung_injury_score(250, 8, 50, 1)