THE CLINICAL CHALLENGE

Comorbid illnesses are common in the older population, and for any given illness or injury, older adults have a worse outcome than younger adults. Aging causes progressive deterioration in physiologic reserve often exacerbated by preexisting chronic conditions, so the elderly are at increased risk of peri-intubation adverse events.

Advanced age affects airway management decision making in four principal areas. Cardiovascular morbidity, pulmonary pathology, frailty syndromes, and chronic underlying conditions are particularly relevant in avoiding the pitfalls of airway management in geriatric patients.

Older patients requiring emergency airway management are likely to have significant comorbidities. Older adults are also increasingly obese and paradoxically most likely to be malnourished. Older adults may require airway management for multiple reasons; however, their expected clinical course is often the most important factor in deciding to intubate in the emergency department (ED). Even without an immediate threat to oxygenation, ventilation, or airway protection, the geriatric patient often has a more prolonged and complex clinical course requiring airway support as part of their therapy. Conversely, the use of noninvasive ventilation techniques may provide an important ventilator bridge during information gathering, medical decision making and family discussions.

Decreased Cardiorespiratory Reserve

Age-related changes in the lungs impair gas exchange, reducing oxygen tension at baseline. The normal PaO₂ falls by 4 mm Hg per decade after the age of 20. Total lung capacity does not change significantly, but functional residual capacity (FRC) and closing volume (CV) increase with age. CV increases more than FRC, leading to atelectasis, especially in the supine position. Reduced sensitivity of central respiratory drive, weakened respiratory muscles, and altered chest wall mechanics impair the ability of the older adult to respond to hypoxia and hypercarbia. Consequently, oxygen saturation may fall rapidly in the face of a respiratory threat. Older patients are also at risk of pulmonary aspiration because of blunted airway reflexes, swallowing disorders, drug effects, and delayed gastric emptying. Older patients with chronic obstructive pulmonary disease (COPD) or obstructive sleep apnea may live with partially compensated respiratory insufficiency, be on home oxygen, or require respiratory support at baseline through nasal continuous positive airway pressure (CPAP) machines.

The aging heart has reduced contractility and limited coronary blood flow, and dysrhythmias, such as atrial fibrillation, further impair the ability to increase cardiac output. β-blockers and calcium channel blockers may limit responses to physiologic stresses by preventing compensatory elevations in heart rate. A relatively fixed cardiac output impairs the physiologic response to the hypotensive effects of intubation drugs. Finally, the presence of cardiovascular or cerebrovascular disease reduces the patient’s tolerance of hypoxemia or hypotension.

Older patients are more likely to present to the ED in cardiac arrest. The optimal airway management strategy in primary cardiac arrest has come under scrutiny recently. Definitive airway placement is not required in the immediate arrest period. Providers should focus on quality chest compressions and limiting overventilation, which can impede venous return. This is discussed in more detail in the Evidence section. Nonetheless, if intubation is performed, a patient in cardiac arrest is generally a technically straightforward intubation as they are flaccid and without protective reflexes. Management should follow the crash airway algorithm as discussed in Chapter 3.

Increased Incidence of Difficult Airway

Advanced age is a marker for difficult bag-mask ventilation (BMV) (see Chapter 2). Older patients also have an increased incidence of difficult direct laryngoscopy, although this is not a factor of age itself, but rather a result of impairment of neck mobility and mouth opening. A fixed flexion deformity of the neck may be unrecognized until the pillow is removed prior to intubation; intubation with conventional laryngoscopy is challenging under these conditions and patients with rheumatoid arthritis may have unstable upper cervical spines. The mucosa of older adults is more friable, often desiccated, and less elastic, making them more vulnerable to damage. Similarly, changes associated with aging and the cumulative effects of disease cause difficulty with the insertion of extraglottic devices (EGDs) and provision of a surgical airway. For all of these reasons, maximizing the opportunity for first-attempt success through proper positioning, robust preoxygenation, and the liberal use of intubating introducers and videolaryngoscopy is recommended.

Ethical Considerations

In airway management, as in all other aspects of resuscitation, the patient’s preferences regarding therapeutic interventions must be respected. Advanced age in and of itself is not a contraindication to advanced airway intervention. Poor outcomes relate more to functional limitation and comorbidities rather than to chronologic age. In cases where life-sustaining interventions are either inappropriate or not desired, noninvasive positive pressure ventilation can provide respiratory assistance and comfort. CPAP or bilevel positive airway pressure can also act as a temporizing measure when data are lacking and information about advanced directives is gathered prior to intubation.

APPROACH TO THE AIRWAY

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