Christine Westphal, MSN NP ACNS ACHPN
Noninvasive ventilation (NIV) is a therapy that has gained increased interest and clinical application. It can be life saving and life prolonging; however, situations may arise when difficult decisions must be made about offering, withholding, or withdrawing the therapy.
NIV refers to the provision of volume- or pressure-supported oxygenation and ventilation, intermittently or continuously, without invasive endotracheal intubation or a tracheostomy. All NIV therapies can provide oxygen, but they vary in relation to inspiratory and expiratory pressure and tidal volume delivery, depending upon the modality. Volume preset devices deliver a set tidal volume in the face of changing airway and lung resistance, but may place airways at risk as a result of high peak pressures. Pressure systems deliver variable volumes using inspiratory positive airway pressure to optimize tidal volume and decrease the work of breathing. Pressure systems may also deliver expiratory positive airway pressure to help remove carbon dioxide, recruit alveoli to reduce atelectasis, and improve sleep apnea. Newer machines can offer both features. For the purposes of this article, the term NIV will be broadly used to encompass continuous positive airway pressure, bilevel positive airway pressure, average volume-assured pressure support (eg, AVAPS™ Respironics), or any combination thereof.1