AAST Bladder Injury Scale AAST Bowel Injury Scale AAST Cardiac Injury Scale AAST Diaphragm Injury Scale AAST Hepatic Injury Scale AAST Kidney Injury Scale AAST Lung Injury Scale AAST Pancreatic Injury Scale AAST Rectal Injury Scale AAST Splenic Injury Scale AAST Vascular Injury Scale ABC Score (Massive Transfusion)ACS COT Field Triage Guidelines ATLS Hemorrhagic Shock Classification Abbreviated Injury Scale (AIS)Ankle-Brachial Index (ABI) in Trauma Base Deficit in Trauma Brain Injury Guidelines (BIG) Score Cardiac Wound Index Chest Trauma Score (CTS)Damage Control Decision Score (DCDS)Denver Criteria (BCVI)Esophageal Perforation Severity Score (PSS)Expanded Denver Criteria (BCVI)Flint Colon Injury Scale Frailty Index in Trauma (mFI-5)Geriatric Trauma Outcome Score (GTOS)Hard Signs of Vascular Injury Checklist Hemorrhage Control Decision Aid (Wound Packing vs. Tourniquet)ICP-based Cerebral Perfusion Pressure (CPP) Calculator Injury Severity Score (ISS)Injury Severity Score — Age-adjusted (ISS-Age)Lethal Triad / Trauma Triad of Death Calculator Limb Salvage Index (LSI)Mangled Extremity Severity Score (MESS)Mechanism, Glasgow Coma Scale, Age, and Arterial Pressure (MGAP)Memphis Criteria (BCVI)Modified Shock Index (MSI)Nerve Injury, Ischemia, Soft-tissue, Skeletal Injury, Shock, Age (NISSSA)New Injury Severity Score (NISS)Open Abdomen Classification (Björck)Pediatric Trauma Score (PTS)Pelvic Trauma Hemorrhage Risk Score Penetrating Abdominal Trauma Index (PATI)Physiologic Extreme Emergency in Trauma (FEET)Predictive Salvage Index (PSI)REBOA Zone Selection Guide Resuscitative Thoracotomy Indications (EAST/WTA Guidelines)Revised Trauma Score (RTS)RibScore Shock Index (SI)TASH Score TRISS Index Thoracic Trauma Severity Score (TTS)Tile Classification of Pelvic Fractures Trauma and Injury Severity Score — Pediatric (PTS)Young–Burgess Pelvic Fracture Classification

Modified Shock Index (MSI)

Hemodynamic Index

Heart Rate (bpm)

Systolic BP (mmHg)

Diastolic BP (mmHg)

Formula: MSI = Heart Rate / Mean Arterial Pressure (MAP)

Enter Vital Signs

Provide Heart Rate and Blood Pressure to evaluate global hemodynamic status.

Guidelines & Evidence

Verified

Last Review: 2026

When to Use

The Modified Shock Index (MSI) is a refinement of the traditional Shock Index (SI). By substituting Mean Arterial Pressure (MAP) for Systolic Blood Pressure (SBP), the MSI accounts for the contribution of diastolic pressure to global perfusion and systemic vascular resistance. It is specifically designed to identify "occult shock"—a state where a patient has significant hemorrhage but remains normotensive due to compensatory mechanisms.

Feature	Shock Index (SI)	Modified Shock Index (MSI)	Age-SI
Formula	HR / SBP	HR / MAP	Age × SI
Normal Range	0.5 – 0.7	0.7 – 1.3	< 50
Sensitivity	Moderate	Higher	Highest (Geriatric)
Complexity	Low	Moderate (requires MAP)	Low

Last Comprehensive Review: 2026

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