Emergency Medicine Calculators

Assesses level of consciousness via eye, verbal, and motor responses

Estimates pre-test probability of pulmonary embolism

Estimates pre-test probability of deep vein thrombosis

Rules out PE without further testing in low pretest probability patients

Objective clinical score for pre-test probability of pulmonary embolism

Estimates 30-day mortality risk and guides admission decisions in community-acquired pneumonia

National Early Warning Score 2 — identifies patients at risk of deterioration

Quick bedside screen for sepsis-related organ dysfunction outside ICU

Quantifies organ dysfunction in ICU/HDU; sequential increase ≥2 defines sepsis

Predicts 2-day stroke risk following a transient ischaemic attack

Estimates likelihood of acute appendicitis in patients with right iliac fossa pain

Determines need for ankle and foot X-ray following acute injury

Determines need for knee X-ray following acute knee injury

Identifies patients who can have cervical spine cleared without radiography

Grades amount of subarachnoid blood on CT to predict vasospasm risk

Predicts survival probability in trauma using GCS, systolic BP, and respiratory rate

Estimates probability of Group A Streptococcal pharyngitis to guide testing and antibiotic use

Bedside early warning score to identify patients at risk of clinical deterioration

Estimates risk of mortality in upper GI bleeding before endoscopy

Determines need for N-acetylcysteine (NAC) treatment following paracetamol (acetaminophen) overdose based on serum level and time post-ingestion

Standardised questionnaire to assess the probability that an adverse drug reaction (ADR) is caused by a specific drug

Calculates the difference between measured and calculated serum osmolality to detect unmeasured osmoles (e.g. toxic alcohols, mannitol)

Estimates blood alcohol concentration (BAC) using the Widmark formula based on drinks consumed, body weight, sex, and drinking duration

Estimates severity of acute salicylate (aspirin) poisoning based on serum salicylate level and hours post-ingestion

Predicts in-hospital mortality in non-traumatic adult ED patients using 6 physiological variables: age, MAP, HR, RR, SpO₂, and GCS

Determines need for cervical spine imaging after blunt trauma. Validated in alert, stable patients. More specific than NEXUS.

Five low-risk criteria to rule out cervical spine injury without imaging in blunt trauma patients. All criteria must be met to clear.

Clinical decision rules to guide radiography in ankle and knee injuries. Highly sensitive for fracture; reduces unnecessary imaging.

Coma scale assessing eye response, motor response, brainstem reflexes, and respiration. Outperforms GCS for intubated patients.

Predicts 30-day mortality in acute pulmonary embolism. Guides decision between inpatient vs outpatient management.

Identifies systemic inflammatory response syndrome (SIRS) and sepsis. Two or more SIRS criteria with suspected infection = sepsis (Sepsis-2 definition).

Predicts likelihood of ureteral stone on CT KUB in patients presenting with suspected renal colic. Helps avoid unnecessary CT in low-risk patients.

Systematic ABCDE primary survey documentation for trauma and critically ill patients per ATLS/ALS. Identifies life-threatening conditions requiring immediate intervention.

Assigns Manchester Triage System priority category based on presenting discriminators. Determines maximum wait time for clinical assessment.

Physiological trauma severity score using GCS, systolic BP, and respiratory rate. Used for triage, survival prediction, and outcome benchmarking.

Guides reperfusion strategy in STEMI: primary PCI vs thrombolysis based on time from symptoms, accessibility, and contraindications per ESC/NICE guidelines.

Combines NICE CG176 and Canadian CT Head Rule criteria for immediate CT head in adults with head injury. Reduces unnecessary CT while identifying neurosurgically significant injuries.

Numerical Rating Scale (0-10) for pain assessment. Guides analgesic ladder escalation in ED and inpatient settings per WHO/BPS guidelines.

Predicts 28-day mortality in adult ED sepsis (Shapiro 2003). Sums 9 weighted criteria.

Modification of the Injury Severity Score (Osler 1997). Sum of squares of the AIS scores of the three most severe injuries regardless of body region. Range 0–75 (any AIS 6 → automatic 75). Better predictor of mortality than ISS in penetrating and blunt trauma.