Over the last decade, noninvasive ventilation—now used almost exclusively with positive pressure—has seen a revival. It’s safer, more comfortable, and more convenient than ventilation involving an artificial airway. But it’s not for everyone.
During the early 20th century, ventilatory assistance generally was noninvasive and involved the delivery of negative pressure. The prime example is the iron lung used to treat patients with postpolio syndrome. By the 1960s, with advances in artificial airways and positive-pressure application, mechanical ventilation using artificial airways became the standard of care for patients in acute respiratory failure.
Respiratory failure may result from central nervous system failure, primary lung disease (such as chronic obstructive pulmonary disease [COPD]), infection, neuromuscular disease, or traumatic injury (such as pulmonary contusion, hemothorax, or pneumothorax). Depending on the abruptness and severity of the precipitating event, these conditions may necessitate immediate artificial airway insertion and mechanical ventilation. However, if respiratory failure progresses over time and the patient can sustain some respiratory reserve, a trial of noninvasive positive-pressure ventilation (NPPV) may be a good alternative to invasive ventilation.
Positive perks
In its latest incarnation, noninvasive ventilation uses positive rather than negative pressure. NPPV may decrease intubation complications—particularly hospital-acquired pneumonia and airway injury—while preserving the patient’s airway defense mechanisms, speech, and swallowing. What’s more, it can be initiated, discontinued, and reinitiated easily in patients who need only intermittent ventilatory support.
NPPV may be especially useful for “Do not intubate” patients, such as those with end-stage COPD, who may develop an infection and require ventilatory support but don’t want or need intubation. NPPV also allows the use of ventilatory support in such patient care areas as emergency departments and rehabilitation units.