Effect of High-Flow Nasal Cannula on Thoraco-Abdominal Synchrony in Adult Critically Ill Patients

Abstract

BACKGROUND: High-flow nasal cannula (HFNC) creates positive oropharyngeal airway pressure and improves oxygenation. It remains unclear, however, whether HFNC improves thoracoabdominal synchrony in patients with mild to moderate respiratory failure. Using respiratory inductive plethysmography, we investigated the effects of HFNC on thoraco-abdominal synchrony. METHODS: We studied 40 adult subjects requiring oxygen therapy in the ICU. Low-flow oxygen (up to 8 L/min) was administered via oronasal mask for 30 min, followed by HFNC at 30 -50 L/min. Respiratory inductive plethysmography transducer bands were circumferentially placed: one around the rib cage, and one around the abdomen. We measured the movement of the rib-cage and abdomen, and used the sum signal to represent tidal volume (V T ) during mask breathing, and at 30 min during HFNC. We calculated the ratio of maximum compartmental amplitude (MCA) to V T , and the phase angle. We assessed arterial blood gas and vital signs at each period, and mouth status during HFNC. We used multiple regression analysis to identify factors associated with improvement in thoraco-abdominal synchrony. RESULTS: During HFNC, breathing frequency significantly decreased from 25 breaths/min (IQR 22-27 breaths/min) to 21 breaths/min (IQR 18 -24 breaths/min) (P < .001), and MCA/V T (P < .001) and phase angle (P ‫؍‬ .047) significantly improved. CONCLUSIONS: HFNC improved thoraco-abdominal synchrony in adult subjects with mild to moderate respiratory failure.

Use of High-Flow Nasal Cannula for Acute Dyspnea and Hypoxemia in the Emergency Department

“…Improvement of dyspnea by HFNC can be explained by several mechanisms, including the high gas flow matching subjects' demand, 13 decreased pharyngeal dead space, 5,14,15 low levels of positive airway pressure, [16][17][18][19] improved thoracoabdominal synchrony, 20 and reduced symptoms of mucosal dryness with heated-and-humidified gas. [21][22][23] In addition, all of these mechanisms also explain why HFNC improved gas exchange and subject comfort.…”

Physiologic Effects of High-Flow Nasal Cannula Oxygen in Critical Care Subjects

“…The tip of the oxygen analyzer was introduced via a small hole in the face mask. 17 HFNC Device. We used the Optiflow HFNC device (Fisher & Paykel Healthcare, Auckland, New Zealand).…”

“…Data on ICU subjects with respiratory failure are scarce. [15][16][17][18] In these studies, HFNC had a beneficial effect on clinical signs and oxygenation in subjects with acute respiratory failure. However, to our knowledge, a rigorous assessment of inspiratory effort and oxygenation has not been performed.…”

For Critically Ill Patients, Is High-Flow Nasal Cannula Oxygen Delivery a Suitable Alternative to Mechanical Ventilation?

“…4 For patients with hypoxemic respiratory failure, how well does cannula delivery work in maintaining stable F IO 2 and positive pharyngeal pressure? From the reported physiological effects of HFNC, although it has been effective for mild-to-moderate hypoxemic respiratory failure, 5 it has not been recommended for severe hypoxemic respiratory failure because it is not possible to ensure sufficient positive pharyngeal pressure. Sztrymf et al 6 evaluated HFNC in subjects with mild-to-moderate respiratory failure in a cardiothoracic care unit: HFNC treatment was successful for 26 (68%) of the 38 subjects who received it.…”