1 Respiratory Assessment and Stabilization

Start with a rapid assessment

Respiratory problems can worsen quickly. These principles apply to adults; children and some other patient groups require different targets and protocols. Follow local emergency procedures and work within your training.

Use the ABCDE sequence to find and address life-threatening problems as they arise. Call for help early and repeat the assessment after interventions. A patient who can speak only a few words, appears exhausted, or has altered consciousness may be critically ill.

Assess airway, breathing, and other vital signs

Check whether the patient can speak and whether airflow is unobstructed. Listen for snoring, gurgling, or stridor; look for choking, secretions, swelling, or reduced consciousness. Airway obstruction is an emergency: summon skilled help and use airway-opening techniques, suction, or airway adjuncts only if trained to do so.

Assess breathing directly and record the respiratory rate, depth, and pattern. A rising rate, shallow breathing, pauses, or irregularity can signal deterioration. Look for increased work of breathing, including accessory-muscle use, retractions, nasal flaring, tripod posture, paradoxical movement, sweating, or inability to speak comfortably.

Compare chest movement and air entry on both sides. Listen for wheeze, crackles, stridor, or markedly reduced or absent breath sounds. A quiet chest is not always reassuring: in severe asthma, markedly reduced air movement or a silent chest can indicate critical airflow obstruction. Sudden loss of breath sounds on one side with acute distress may indicate a time-critical chest emergency.

Measure and record oxygen saturation, the oxygen device, and its flow or concentration. Interpret the reading alongside the patient’s appearance and the trend, rather than in isolation.

For circulation, check pulse, blood pressure, skin perfusion, and cardiac rhythm when available. Assess alertness and confusion, which can reflect low oxygen, carbon-dioxide retention, shock, or another cause. Expose enough to examine the chest and look for trauma while preventing heat loss. Seek relevant history—including asthma or COPD, usual oxygen target, home oxygen, recent infection, medications, allergies, and symptom onset—without delaying urgent treatment.

Distinguish oxygenation from ventilation

Oxygenation is the transfer of oxygen into the blood; ventilation is the movement of air that removes carbon dioxide ($\mathrm{CO_2}$). A patient may have low oxygen, inadequate carbon-dioxide removal, or both. Supplemental oxygen can improve oxygenation but does not necessarily correct poor ventilation.

A pulse oximeter estimates oxygen saturation, but it does not measure carbon dioxide or show how hard the patient is working to breathe. Blood gas testing and, in appropriate settings, capnography can help assess ventilation.

Pulse-oximeter readings can be affected by poor circulation, movement, skin temperature, nail products, and skin pigmentation. Check signal quality and compare the reading with the clinical picture. Do not let a reassuring number override visible distress or deterioration.

Use oxygen carefully and reassess

Oxygen is a treatment to correct hypoxemia, not a substitute for assessment. For adults in acute care, the recommended target oxygen saturation is $94\%$ to $98\%$ for most patients and $88\%$ to $92\%$ for patients with COPD. A prescribed target or documented oxygen alert plan may differ; use it when available and follow local protocols. If hypercapnic respiratory failure is suspected, clinicians commonly use a controlled target while arranging blood-gas assessment. Avoid both untreated hypoxemia and unnecessary excess oxygen.

Nasal cannulae are commonly used for lower supplemental oxygen needs, face masks for greater needs, and reservoir masks for high-concentration oxygen in an emergency. The appropriate device depends on severity, target, and clinical setting. Confirm that the oxygen source and device are functioning, and document the device and flow or concentration.

After each change, reassess saturation, respiratory effort, mental status, and the trend. Oxygen supports oxygenation; when breathing does not adequately move air and remove $\mathrm{CO_2}$, ventilation support may also be needed.

Recognize impending respiratory failure

Escalate promptly if the patient develops any of the following:

• Increasing respiratory rate or effort, exhaustion, or diminishing respiratory effort after a period of distress.

• Inability to speak, poor air movement, a silent chest, severe wheeze, stridor, or rapidly worsening breath sounds.

• Falling oxygen saturation, hypoxemia despite oxygen, or a rising oxygen requirement.

• New confusion, agitation, drowsiness, cyanosis, or reduced responsiveness.

• Apnea, gasping, or ineffective breathing.

A patient who becomes quieter or less agitated is not necessarily improving: fatigue and reduced consciousness may signal failure. Respiratory failure may involve inadequate oxygenation, inadequate carbon-dioxide removal, or both.

Stabilize, reassess, and escalate

1. Call for help early. Activate the local emergency or rapid-response system for severe distress, altered consciousness, or worsening observations. Team members can assess, monitor, and prepare equipment in parallel.

2. Position and support. If tolerated, sit the patient upright, maintain airway patency, and allow rest. Attach appropriate monitoring and obtain vital signs. Do not delay urgent care to complete a detailed history or examination.

3. Treat immediate threats within training and protocol. Give and titrate oxygen to the appropriate target. If breathing is absent or inadequate, emergency bag-mask ventilation may be needed from a trained responder while advanced help is summoned. Noninvasive ventilation or an advanced airway requires appropriate expertise, monitoring, and assessment of suitability.

4. Address the likely cause. Stabilization is a bridge to definitive care. Asthma, COPD exacerbation, pneumonia, airway obstruction, pneumothorax, pulmonary edema, and other causes need cause-specific treatment by qualified clinicians.

5. Reassess and communicate. Repeat ABCDE after interventions and whenever the patient changes. Use a structured handover such as SBAR to report the trend, oxygen device and requirement, key findings, interventions, and response.

If a person is unresponsive and not breathing normally, activate emergency services and begin CPR/AED actions according to training and local guidance.