HEAVEN Criteria (Difficult Emergency Airway)
The HEAVEN criteria for anticipating a difficult EMERGENCY airway (Kuzmack and colleagues, J Emerg Med 2018).
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- H - Hypoxemia
- Yes
- E - Extremes of size
- No
- A - Anatomic challenge
- Yes
- V - Vomit, blood or fluid
- Yes
- E - Exsanguination
- No
- N - Neck mobility
- No
Result: HEAVEN: 3 of 6 criteria present
The tool opens with these values already filled in. Replace them with your own.
What the result means
- H
- Hypoxemia: SpO2 93% or below AT THE TIME OF LARYNGOSCOPY.
- E
- Extremes of size: age 8 or under, or clinical obesity. Obesity is DELIBERATELY undefined - no BMI cutoff.
- A
- Anatomic challenge anticipated to limit the laryngoscopic view.
- V
- Vomit/blood/fluid in the pharynx anticipated to interfere.
- E
- Exsanguination: SUSPECTED ANEMIA, not bleeding. Scored for safe apnea time.
- N
- Neck: limited cervical range of motion.
- Published figures
- ONLY two: ~94% first-attempt success at 0 criteria, ~43% at 5 or more. Do NOT interpolate.
- Timing
- Assessed at laryngoscopy, not on arrival. Preoxygenation can un-score hypoxemia.
- Scope
- Anticipates difficulty. A count of zero does not make an airway safe.
What you enter
- H - Hypoxemia.
- E - Extremes of size.
- A - Anatomic challenge.
- V - Vomit, blood or fluid.
- E - Exsanguination.
- N - Neck mobility.
Full field descriptions
- H - Hypoxemia. Oxygen saturation 93 percent or below at the time of initial laryngoscopy. Assessed at the moment of laryngoscopy, not on arrival.
- E - Extremes of size. A pediatric patient 8 years of age or under, or clinical obesity that the operator anticipates will interfere with bag-valve-mask ventilation or with visualizing the glottis. Obesity is deliberately left undefined: there is no body mass index threshold. OPERATOR JUDGMENT, not a measurement. Assessed at the moment of laryngoscopy, not on arrival.
- A - Anatomic challenge. Any structural abnormality anticipated to limit the laryngoscopic view: airway trauma, limited oral aperture, large tongue, short neck, mass or swelling, foreign body, or an external structure obstructing visualization. OPERATOR JUDGMENT, not a measurement. Assessed at the moment of laryngoscopy, not on arrival.
- V - Vomit, blood or fluid. Clinically significant fluid in the pharynx or hypopharynx before laryngoscopy, anticipated to interfere with bag-valve-mask ventilation or with visualizing the glottis. OPERATOR JUDGMENT, not a measurement. Assessed at the moment of laryngoscopy, not on arrival.
- E - Exsanguination. SUSPECTED ANEMIA, chronic or acute, raising concern about shortening safe apnea time. This is NOT active bleeding: it is anticipated desaturation reserve. OPERATOR JUDGMENT, not a measurement. Assessed at the moment of laryngoscopy, not on arrival.
- N - Neck mobility. Limited cervical range of motion, from immobilization or from arthritis. OPERATOR JUDGMENT, not a measurement. Assessed at the moment of laryngoscopy, not on arrival.
How this is calculated
- Structure
- A COUNT of criteria present (0-6). No point score and NO band table.
Kuzmack E, Inglis T, Olvera D, Wolfe A, Seng K, Davis D. A Novel Difficult-Airway Prediction Tool for Emergency Airway Management: Validation of the HEAVEN Criteria in a Large Air Medical Cohort. J Emerg Med. 2018;54(4):395-401. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.