The Mangled Extremity Severity Score (MESS) is a clinical calculator used in the field of trauma surgery, specifically for patients with severe limb injuries. It is designed to predict the need for amputation following a traumatic extremity injury. The MESS takes into account factors such as the patient's age, injury mechanism, presence of shock, and the degree of soft tissue, skeletal, and neurovascular damage. The higher the MESS, the higher the likelihood of requiring amputation. This calculator is particularly useful in guiding clinical decision-making and informing discussions with patients and their families about potential outcomes. It should not be used in isolation, but rather as part of a comprehensive clinical assessment. The MESS may not be applicable or accurate in all cases, particularly in patients with certain comorbidities or in those with injuries that do not fit neatly into the scoring system.

Mangled Extremity Severity Score for prediction of amputation (MESS)

# Criteria
 ## Limb ischemia
A. Pulse reduced/absent, perfusion normal (ischemia < 6 hours) (+1)
B. Pulseless, paresthesias, diminished capillary refill (ischemia for < 6 hours) (+2)
C. Cool, paralysed, numb/insensate (ischemia for < 6 hours) (+3)
D. Pulse reduced/absent, perfusion normal (ischemia > 6 hours) (+2)
E. Pulseless, paresthesias, diminished capillary refill (ischemia for > 6 hours) (+4)
F. Cool, paralysed, numb/insensate (ischemia for > 6 hours) (+6)
## Patient age
G. < 30 (+0)
H. 30-50 (+1)
I. >= 50 (+2)
## Shock
J. Systolic blood pressure > 90 mmHg consistently (+0)
K. Transient hypotension (+1)
L. Persistent hypotension (+2)
## Skeletal/soft tissue injury
M. Low energy (stab, simple fracture, "civilian" gunshot) (+1)
N. Medium energy (open/multiple fractures, dislocation) (+2)
O. High energy (close-range shotgun or "military" gunshot, crush injury) (+3)
P. Very high energy (soft-tissue avulsion, high speed trauma with gross contamination) (+4)

# Conditions
- score <= 6
- score >= 7
- score == 0