When should a patient be intubated (insertion of an endotracheal tube)?

When to Intubate: Clinical Guidelines

Endotracheal intubation should be performed without delay in patients with airway obstruction, altered consciousness (Glasgow Coma Scale ≤ 8), hypoventilation, or hypoxemia to prevent further deterioration and reduce mortality. 1

Primary Indications for Intubation

• Airway obstruction: When the patient cannot maintain a patent airway due to anatomical or functional obstruction 1
• Altered consciousness: GCS ≤ 8, indicating inability to protect the airway 1
• Respiratory failure: Characterized by hypoxemia (PaO₂ < 60 mmHg despite high-flow oxygen) or hypoventilation (PaCO₂ > 50 mmHg with pH < 7.35) 1
• High respiratory rate: Respiratory rate > 35 breaths/min, indicating severe respiratory distress 1
• Vital capacity: When vital capacity falls below 15 ml/kg 1

Specific Clinical Scenarios Requiring Intubation

Trauma Patients

• Perform immediate intubation in trauma patients with GCS ≤ 8 1
• Consider intubation when there is risk of aspiration due to facial/neck trauma 1
• Intubate patients with severe hemorrhagic shock to facilitate adequate ventilation 1

Stroke Patients

• Intubate patients with decreased level of consciousness who cannot protect their airway 1
• Consider intubation in patients with brain stem dysfunction due to impaired oropharyngeal mobility and loss of protective reflexes 1
• Intubation may be necessary to manage severely increased intracranial pressure or malignant brain edema 1

Sepsis and Respiratory Failure

• Intubate if patients cannot adequately protect their airway 1
• Consider intubation with refractory hypoxemia despite non-invasive ventilation 1
• Intubate when there is evidence of increased work of breathing that may lead to respiratory muscle fatigue 1

Intubation Technique Considerations

• Rapid sequence induction is generally the preferred method for emergency intubation 1
• Orotracheal intubation is preferred over nasotracheal intubation due to lower rates of sinusitis 1
• The most experienced available operator should manage the airway to minimize complications 2, 3

Monitoring During and After Intubation

• Monitor for cardiovascular instability, which occurs in 42.6% of emergency intubations 3
• Watch for severe hypoxemia (SpO₂ < 80%), which occurs in 9.3% of intubations 3
• Be prepared for cardiac arrest, which occurs in 3.1% of emergency intubations 3
• Ensure adequate oxygenation with a target saturation of approximately 90% (PaO₂ around 60 mmHg) 1

Cautions and Special Considerations

• Avoid hyperoxemia (except in imminent exsanguination) as it may worsen outcomes 1
• Aim for normoventilation in most trauma patients; consider hyperventilation only for signs of cerebral herniation 1
• Be aware that intubation carries significant risks - the overall mortality of intubated stroke patients is approximately 50% within 30 days 1
• Recognize that delayed intubation (≥15 days after symptom onset in respiratory failure) is associated with increased mortality 4
• Consider permissive hypercapnia in patients at risk for barotrauma/volutrauma, maintaining arterial pH above 7.20 5

When to Consider Non-Invasive Ventilation Instead

• In COPD exacerbations and cardiogenic pulmonary edema before proceeding to intubation 6
• In patients with chronic respiratory diseases where NIV failure rates are lower (15%) compared to those without underlying chronic respiratory disease (38%) 6
• When patients have adequate mental status to cooperate with NIV 1

Common Pitfalls to Avoid

• Delaying intubation in patients with clear indications, which can lead to increased mortality 4
• Overreliance on GCS alone for intubation decisions in drug overdose patients 7
• Failing to anticipate and prepare for cardiovascular instability during intubation 3, 8
• Neglecting to administer concurrent fluid in hypovolemic patients, as positive intrathoracic pressure can induce severe hypotension 1

Remember that intubation is not a therapeutic intervention by itself but a supportive measure until the underlying condition improves 1. The decision to intubate should be made promptly when indicated, as both premature and delayed intubation can lead to adverse outcomes.