Estimated Blood Alcohol Concentration
Estimates blood alcohol concentration (BAC) using the Widmark formula based on drinks consumed, body weight, sex, and drinking duration
Score interpretation
BAC < 0.02 g/dL: Negligible behavioural effects.
→ No clinical intervention required for alcohol alone.
BAC 0.02–0.05 g/dL: Mild relaxation, slight impairment of judgement.
→ Advise not to drive. Supportive management.
BAC 0.05–0.15 g/dL: Coordination impaired, slurred speech, emotional lability.
→ Monitor. Assess for co-ingestion, head injury, hypoglycaemia. IV access if >0.10.
BAC 0.15–0.30 g/dL: Severe CNS depression, risk of aspiration.
→ IV fluids, thiamine (Pabrinex), monitor glucose. Recovery position. Consider ICU if unresponsive.
BAC > 0.30 g/dL: Risk of respiratory depression, coma, death.
→ Immediate resuscitation. Airway management. ICU admission. Rule out co-ingestion with paracetamol, benzodiazepines, opioids.
Interpretation bands for the Est. BAC. Apply clinical judgement and local guidance.
References
- Widmark EMP. A micromethod for the estimation of the alcohol content of blood and the use of alcohol in forensic medicine. Biochem Z. 1932;247:281–293.
Related
Curated clinical cross-links plus same-class fallbacks.
- Difficult Airway Algorithm (DAS) · DAS 2015; Royal College of Anaesthetists
- Major Haemorrhage Protocol · NICE NG24; UK MHP guidelines
- New-Onset Atrial Fibrillation · ESC 2020 AF Guidelines; NICE NG196
- Hypertensive Emergency · ESC/ESH 2018 Hypertension Guidelines; NICE NG136
- Bradycardia Management · Resuscitation Council UK ABCDE; ESC 2021 Pacing Guidelines
- Ventricular Tachycardia / Fibrillation · Resuscitation Council UK ACLS; ESC 2022 Ventricular Arrhythmia Guidelines
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.