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KEY POINTS
Noninvasive oxygenation and ventilation strategies have been found to reduce the need for endotracheal intubation and mortality across a wide spectrum of respiratory failure conditions.
High-flow nasal cannula systems are a valuable supplement to conventional mask-delivered noninvasive ventilation (NIV) for patients with acute exacerbation of chronic obstructive pulmonary disease, cardiogenic pulmonary edema, and postoperative respiratory failure in patients with impending acute respiratory failure (ARF).
Patients requiring invasive mechanical ventilation (IMV) after NIV failure have greater odds of death compared with patients directly placed on invasive ventilation and those successfully treated with NIV without transition to invasive ventilation.
NIV, including use of a helmet interface, has increased significantly during the COVID-19 pandemic for the treatment of acute hypoxemic respiratory failure with the use of specific precautions regarding aerosolization risk.
Extubation to immediate NIV is beneficial in patients with hypercapnic ARF and is effective as an alternative to continuing invasive MV in highly selected patients recovering from AHRF.
NIV can be used in patients with ARF who are poor candidates for intubation because of advanced age, debilitation, or a “do-not-intubate and/or -resuscitate” order.
Adverse effects linked with NIV include skin breakdown and ulcers, air leaks and patient-ventilator asynchrony, abdominal distention and regurgitation, cough and communication impairment, and patient intolerance.
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Noninvasive oxygenation and ventilation strategies are important tools that can be used to support patients with oxygenation or ventilation derangements in the setting of acute respiratory failure (ARF). Across numerous conditions, they have been found to reduce the need for endotracheal intubation and mortality. Their role across de-novo acute hypoxemia respiratory failure (AHRF) and postextubation respiratory failure remains less clear. They have the advantage of sustaining spontaneous breathing and wakefulness in patients; however, if applied for too long across patients who fail to improve, it could lead to risks associated with injurious spontaneous breathing, aspiration, or exhaustion. An understanding of the different noninvasive oxygen devices (noninvasive ventilation [NIV] and high-flow nasal cannula [HFNC]), their physiologic impact, clinical outcomes, and monitoring for failure will be reviewed in this chapter.
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HISTORY AND RATIONALE FOR NONINVASIVE DEVICES
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During the poliomyelitis epidemic, the “iron lung” was the first form of NIV.1,2 Despite saving many lives, the “iron lung” had its limitations: it was cumbersome, difficult to facilitate patient care needs, and limited in its ability to treat parenchymal lung disease or to clear secretions. Invasive positive pressure ventilation allowed more effective delivery of mechanical assistance through an endotracheal tube, which provided access to the lower airway. Following this, positive pressure ventilation became the standard form of mechanical ventilation, coupling the patient to a ventilator via an endotracheal tube.
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Despite this major advancement in ARF management, complications associated with positive pressure ventilation were unveiled in the following decades.3,4 These complications were related directly to (1) endotracheal intubation (hemodynamic changes, laryngeal or tracheal injury, and ...