7 Integrated Impaired Oxygenation Practice Questions

Recognize immediate threats to breathing

In an adult with respiratory symptoms, assess the person rather than relying on a monitor reading alone. Oxygen saturation is one part of the assessment; also consider work of breathing, ability to speak, breath sounds, skin color, mental status, trends, and response to interventions.

Altered alertness, exhaustion, inability to speak normally, severe work of breathing, or a quiet chest can signal failing ventilation and impending respiratory arrest. Restlessness and increased work of breathing may occur before more obvious signs of respiratory failure. Treat these as urgent deterioration, not as reassuring changes.

Stabilize first and escalate

When breathing is deteriorating, stay with the patient and rapidly reassess airway, breathing, oxygenation, and mental status. Position the patient to support breathing, provide or adjust oxygen within protocol, reassess the response, and urgently escalate if the patient is unstable or not improving.

For a patient who is drowsy and can no longer speak in full sentences during a severe asthma attack, especially with a very faint or absent wheeze, activate urgent help and initiate emergency care. A quiet chest in this setting can mean critically reduced airflow, not improvement.

Do not delay stabilization for diagnostic tests, specimen collection, medications, ambulation, or teaching. These may be important, but immediate support for deteriorating breathing takes priority.

Titrate oxygen and reassess

Do not withhold oxygen from a hypoxemic patient. Give oxygen as needed, titrate it to the prescribed target, and reassess breathing and oxygenation. Follow emergency procedures and local protocols.

For many acutely ill patients with COPD or risk of hypercapnic respiratory failure, controlled oxygen targeting $88\text{–}92\%$ is recommended while blood-gas results are pending, unless the patient has an individualized target. Reassess frequently and obtain or review blood gases as ordered. The aim is to correct hypoxemia while avoiding unmonitored, excessive oxygen—not to leave the patient dangerously hypoxemic.

For adults and adolescents with an asthma exacerbation, the stated oxygen target is $93\text{–}95\%$, with escalation for life-threatening signs. Apply the target appropriate to the patient and prescribed plan.

Use patterns to guide assessment

Clinical patterns help guide urgent consideration of causes, but they are clues rather than proof. Assessment and diagnostic testing are needed, and more than one condition may be present.

• Asthma: Often involves variable, episodic airway narrowing. Rapidly worsening wheeze and chest tightness after allergen exposure, accessory-muscle use, or speaking only a few words at a time can indicate a potentially severe exacerbation. Inability to speak normally, drowsiness, confusion, or a silent chest are danger signs.

• COPD: More often involves persistent airflow limitation with chronic symptoms and may include chronic carbon-dioxide retention. In an acute episode, increased breathlessness and low oxygen saturation require treatment and reassessment; oxygen should not be withheld.

• Pneumonia: Fever, cough, productive or purulent sputum, and localized crackles support a lung infection. Confusion, rapid breathing, and marked hypoxemia indicate acute deterioration and possible severe pneumonia or respiratory failure.

• Pulmonary embolism: Sudden, unexplained dyspnea and pleuritic chest pain with tachycardia and low oxygenation are concerning, particularly after recent surgery. Relatively clear breath sounds and no fever do not make these symptoms safe to dismiss. No single symptom confirms the diagnosis.

Asthma and COPD patterns can overlap, and history alone does not rule out pneumonia or pulmonary embolism. Worsening oxygenation or instability takes priority over settling the diagnosis.

Assess ventilation and blood gases

A pulse-oximeter reading cannot by itself reveal whether carbon dioxide is elevated. Consider blood-gas results and mental status when assessing ventilation as well as oxygenation.

For example, a patient with COPD who is more fatigued and difficult to arouse, with $\mathrm{pH}=7.29$, $\mathrm{PaCO_2}=66\ \mathrm{mmHg}$, and $\mathrm{PaO_2}=55\ \mathrm{mmHg}$, is concerning for acute respiratory failure with both hypercapnia and hypoxemia. A low pH with elevated carbon dioxide indicates respiratory acidosis; the low oxygen level indicates hypoxemia. Declining alertness may reflect worsening gas exchange and raises concern about the patient’s ability to protect the airway.

Urgently escalate, support oxygenation, and prepare for further assessment and possible ventilatory support. Oxygen can improve oxygenation, but it does not by itself correct inadequate ventilation or remove carbon dioxide. The team may consider noninvasive ventilation when appropriate, or more advanced airway support if the patient deteriorates or cannot safely use a mask.

Continue care for the suspected cause

Provide cause-specific care after immediate breathing support is underway. For asthma or COPD, administer prescribed bronchodilator treatment; for a severe asthma exacerbation, this can include an inhaled rapid-acting bronchodilator and other ordered acute treatments, with close reassessment. Titrate oxygen to the appropriate target.

For suspected pneumonia, evaluation and treatment of the infection are important, but collecting a sputum specimen or providing antibiotic-course teaching must not delay stabilization. Pneumonia can cause fever, cough, dyspnea, and hypoxemia; respiratory failure requiring ventilatory support is a major severity feature.

For suspected pulmonary embolism, urgently escalate for medical evaluation, support oxygenation as indicated, and monitor for hypotension, fainting, confusion, or other signs of deterioration. Do not delay urgent assessment while trying to establish the diagnosis at the bedside.

• Impaired oxygenation

• Arterial blood gas