cliot (version 1.0.0)

mess_score: Mangled Extremity Severity Score (MESS)

Description

Calculates the Mangled Extremity Severity Score (MESS) to assess the viability of a limb following severe trauma. The score sums points from four categories: Skeletal/Soft-Tissue Injury, Limb Ischemia, Shock, and Age. A score of 7 or higher has been historically associated with a need for amputation, though clinical judgment remains paramount.

Usage

mess_score(skeletal_soft_tissue, limb_ischemia, shock, age,
           ischemia_duration_gt_6h = 0)

Value

A list containing:

MESS_Score

The calculated total score (Range 1-14+).

Interpretation

Clinical interpretation regarding salvage versus amputation risk (Cutoff >= 7).

Arguments

skeletal_soft_tissue

Numeric (1-4). Energy of injury. 1: Low energy (stab, simple fracture, pistol gunshot). 2: Medium energy (open multifragmentary fracture, dislocation). 3: High energy (high-velocity gunshot, crush). 4: Very high energy (gross contamination, soft tissue avulsion).

limb_ischemia

Numeric (0-3). Severity of ischemia. 0: None (Pulse present, perfusion normal). 1: Mild (Pulse reduced/absent, perfusion present). 2: Moderate (Pulseless, paresthesias, diminished capillary refill). 3: Advanced (Pulseless, cool, paralyzed, numb/insensate).

shock

Numeric (0-2). Hemodynamic status. 0: Normotensive (SBP always > 90 mmHg). 1: Transient hypotension. 2: Persistent hypotension.

age

Numeric (0-2). Patient age group. 0: < 30 years. 1: 30-50 years. 2: > 50 years.

ischemia_duration_gt_6h

Numeric (0 or 1). Ischemia duration greater than 6 hours? (1 = Yes). If Yes, the points for the 'limb_ischemia' category are doubled.

References

Johansen K, Daines M, Howey T, Helfet D, Hansen ST Jr. Objective criteria accurately predict amputation following lower extremity trauma. J Trauma. 1990;30(5):568-572.

Examples

# Example 1: High Risk (Amputation Likely)
# High energy (3), Advanced ischemia (3) > 6h (doubled -> 6), Shock (1), Age 30-50 (1)
# Score = 3 + 6 + 1 + 1 = 11
mess_score(3, 3, 1, 1, 1)

# Example 2: Low Risk (Salvage Likely)
# Medium energy (2), Mild ischemia (1) < 6h (1), No shock (0), Age < 30 (0)
# Score = 2 + 1 + 0 + 0 = 3
mess_score(2, 1, 0, 0, 0)