ACCS Respiratory Practice Exam

Noninvasive ventilation works best when the patient can breathe spontaneously, protect their airway, and a good seal can be achieved with a mask. When any factor makes these conditions unsafe or impossible, NIV is not appropriate. Cardiac or respiratory arrest means there’s no effective spontaneous breathing to support gas exchange, so NIV won’t meet the patient’s needs and invasive ventilation is required. An upper airway obstruction prevents airflow despite the applied pressures, so NIV cannot relieve the obstruction. Facial or head trauma often prevents a reliable mask seal and can increase the risk of further injury or aspiration, making NIV unsafe in many cases. Nasal or pharyngeal abnormalities, however, do not automatically rule out NIV. With the right interface and setup—such as an alternative mask that accommodates the anatomy—NIV can still be used safely and effectively.