Physiological Effects of High-Flow Nasal Cannula Therapy and Its Use in Acute Cardiogenic Pulmonary Edema

Abstract

High-flow nasal cannula (HFNC) is an open oxygen delivery system, which provides heated and humidified oxygen at a high flow (up to 60 L/min). This effect can improve mucociliary function, airway clearance, and level of comfort to the patient. It can provide controlled and adequate fraction of inspired oxygen (FiO 2 ) between 21% and 100%. Generation of end-expiratory pressure helps in carbon dioxide washout, reduction of anatomical dead space, and recruitment of collapsed alveoli, ultimately improving tissue oxygenation. The use of HFNC in acute hypoxemic respiratory failure, post-extubation period, pre-intubation period, respiratory infection, and obstructive airway disease has been extensively studied, but there are very few studies regarding its use in cardiogenic pulmonary edema. This review provides the current understanding of the physiological effect of HFNC and its application in acute cardiogenic pulmonary edema (ACPE). We conducted a literature search on PubMed using appropriate terms and reviewed relevant articles published within the last 10 years. We found that initial therapy with HFNC in ACPE patients can improve oxygenation and respiratory rate. HFNC can potentially be an alternative to non-invasive positive-pressure ventilation in terms of initial oxygen therapy in patients with ACPE. There is a need for larger prospective studies to evaluate and develop guidelines to consider the use of HFNC in patients with ACPE. We also highlight the fact that if there is no improvement in arterial blood gas parameters after HFNC therapy, initiation of invasive ventilation should not be delayed.

Clinical review of high-flow nasal oxygen therapy in human and veterinary patients

“…HFNOT has been advocated in the management of pulmonary oedema secondary to acute heart failure in humans ( 157 ). Improvement in oxygenation in these patients is attributed to provision of high FiO 2 , recruitment of collapsed alveoli and decreased preload ( 74 , 157 ).…”

“…HFNOT has been advocated in the management of pulmonary oedema secondary to acute heart failure in humans ( 157 ). Improvement in oxygenation in these patients is attributed to provision of high FiO 2 , recruitment of collapsed alveoli and decreased preload ( 74 , 157 ). A small number of dogs with congestive heart failure have been include in heterogeneous populations in previous studies, however the utility and efficacy in these patients has not been established ( 26 , 28 , 30 ).…”

Negative pressure pulmonary edema due to upper airway obstruction after general anesthesia in a patient with Parkinson’s disease: a case report

“…HFNC is able to deliver a consistent oxygen supply to the alveoli by constantly applying positive pressure, enabling the patient to maintain a high level of oxygen supply. 11 Further, generation of PEEP helps in reduction of anatomical dead space, carbon dioxide washout, recruitment of collapsed alveoli, and ultimate improvement in oxygenation. 11 Through such effects, HFNC improves pulmonary edema.…”

“…11 Further, generation of PEEP helps in reduction of anatomical dead space, carbon dioxide washout, recruitment of collapsed alveoli, and ultimate improvement in oxygenation. 11 Through such effects, HFNC improves pulmonary edema. 11 In addition, HFNC improves UAO in patients with OSA.…”

“…11 Through such effects, HFNC improves pulmonary edema. 11 In addition, HFNC improves UAO in patients with OSA. 12 Therefore, our experience also suggests that HFNC is effective in improving UAO and subsequent NPPE in patients with PD.…”