Reference — NCLEX Success
ABC Priority Framework
The ABC framework — Airway, Breathing, Circulation — is the highest-priority clinical decision rule in nursing. Any patient with a compromised airway, breathing problem, or circulation failure takes absolute priority over all other needs.
Educational use only. In clinical emergencies, follow ACLS protocols, facility emergency response plans, and provider orders. The ABC framework guides initial assessment priorities — it does not replace a full clinical evaluation. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Framework Overview
| Priority | Component | What Nurses Assess | Emergency Indicators |
|---|---|---|---|
| A | Airway | Patency, breath sounds, ability to speak, secretions, stridor, foreign body |
|
| B | Breathing | Respiratory rate, depth, SpO₂, use of accessory muscles, breath sounds, work of breathing |
|
| C | Circulation | Pulse presence and quality, blood pressure, skin color and temperature, capillary refill, bleeding |
|
A — Airway
Airway is the absolute first priority. Without a patent airway, oxygenation and ventilation are impossible. An obstructed airway is a true minutes-count emergency.
Airway threats include:
- Foreign body obstruction — Heimlich maneuver if conscious; back blows and chest thrusts for infants
- Angioedema or anaphylaxis — narrowing from laryngeal edema; epinephrine is life-saving
- Post-extubation stridor — partial laryngospasm or edema; racemic epinephrine, reintubation if needed
- Excessive secretions in unconscious patients — positioning (lateral) and suctioning
- Tongue obstruction in altered consciousness — jaw-thrust, positioning, oral/nasopharyngeal airway adjuncts
- Post-op neck surgery (thyroidectomy, carotid, cervical spine) — swelling or hematoma compressing trachea
NCLEX note:
Post-thyroidectomy patient with stridor, dysphagia, or neck swelling = airway emergency. This is the highest-priority finding in any scenario that includes it.
B — Breathing
Breathing problems — once the airway is patent — represent the second highest priority. Impaired gas exchange leads to hypoxemia, hypercapnia, and death if untreated.
Breathing emergencies:
- Respiratory arrest: Absent breathing; immediate bag-valve-mask ventilation, activate code response
- Tension pneumothorax: Absent unilateral breath sounds, tracheal deviation, JVD, hypotension — call rapid response immediately
- Acute pulmonary edema: Severe dyspnea, pink frothy sputum, SpO₂ rapidly dropping — upright positioning, supplemental O₂, provider notification
- Opioid-induced respiratory depression: Rate < 8–10, shallow, SpO₂ dropping — stimulate patient, administer naloxone per orders
- Severe bronchospasm: Diffuse wheeze, SpO₂ falling — bronchodilators, supplemental O₂, provider notification
Key numbers:
- SpO₂ < 90% = hypoxemia requiring intervention
- RR < 8 or > 30 = abnormal requiring assessment
- PaO₂ < 60 mmHg on ABG = significant hypoxemia
C — Circulation
Circulation failures — once the airway and breathing are assessed — represent the third tier of the ABCs. Inadequate circulation leads to organ failure and death from oxygen debt.
Circulation emergencies:
- Cardiac arrest: Absent pulse — begin CPR, activate code response immediately
- Hemorrhagic shock: Severe bleeding, falling BP, tachycardia — direct pressure, IV access, fluids, type and cross, notify provider
- Septic shock: Hypotension (MAP < 65) despite fluids — vasopressors, antibiotics, sepsis bundle
- Acute MI: Chest pain with ST changes, arrhythmias, hemodynamic compromise — 12-lead ECG, aspirin, provider notification, prepare for intervention
- Dissecting aortic aneurysm: Sudden tearing back pain, unequal arm BP — immediate emergency intervention needed
When ABCs Override Other Frameworks
ABCs take absolute precedence over Maslow levels 2–5 and over delegation, patient education, documentation, and comfort measures. Never delay addressing ABCs for:
- Charting or documentation
- Patient or family teaching
- Discharge planning or education
- Pain assessment (unless pain is causing respiratory compromise)
- Psychosocial support or emotional comfort
- Answering another patient's non-urgent call light
NCLEX rule:
When a question contains an ABC threat, the correct answer involves addressing that threat first — regardless of the other options. Look for airway, SpO₂, hemorrhage, absent pulse, or severe hypotension in the stem.
Clinical Examples
| Scenario | ABC Component | Priority Action |
|---|---|---|
| Post-thyroidectomy patient with audible stridor and neck swelling | A — Airway | Notify surgeon immediately; prepare for emergency airway management; have intubation equipment ready |
| Patient with opioid overdose, RR 6, SpO₂ 82% | B — Breathing | Stimulate patient, supplemental O₂, administer naloxone, call rapid response if no improvement |
| Trauma patient with saturated dressings and BP 82/50 | C — Circulation | Apply direct pressure, establish large-bore IV access, rapid fluid resuscitation, notify surgeon, type and crossmatch |
| Patient found unresponsive, no pulse, no breathing | A + B + C | Call code, begin CPR immediately, apply AED/defibrillator, establish IV access |
Related Resources
Standards & sources
Fact-checked Jun 21, 2026This page is written to align with NCSBN — NCLEX-RN Test Plan · Clinical Judgment Measurement Model (NCJMM). It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →