High-flow nasal oxygen versus noninvasive ventilation in adult patients with cystic fibrosis: a randomized crossover physiological study

Abstract

BackgroundNoninvasive ventilation (NIV) is the first-line treatment of adult patients with exacerbations of cystic fibrosis (CF). High-flow nasal oxygen therapy (HFNT) might benefit patients with hypoxemia and can reduce physiological dead space. We hypothesized that HFNT and NIV would similarly reduce work of breathing and improving breathing pattern in CF patients. Our objective was to compare the effects of HFNT versus NIV in terms of work of breathing, assessed noninvasively by the thickening fraction of the diaphragm (TFdi, measured with ultrasound), breathing pattern, transcutaneous CO2 (PtcCO2), hemodynamics, dyspnea and comfort.MethodsAdult CF patients who had been stabilized after requiring ventilatory support for a few days were enrolled and ventilated with HFNT and NIV for 30 min in crossover random order.ResultsFifteen patients were enrolled. Compared to baseline, HFNT, but not NIV, reduced respiratory rate (by 3 breaths/min, p = 0.01) and minute ventilation (by 2 L/min, p = 0.01). Patients also took slightly larger tidal volumes with HFNT compared to NIV (p = 0.02). TFdi per breath was similar under the two techniques and did not change from baseline. MAP increased from baseline with NIV and compared to HFNT (p ≤ 0.01). Comfort was poorer with the application of both HFNT and NIV than baseline. No differences were found for heart rate, SpO2, PtcCO2 or dyspnea.ConclusionsIn adult CF patients stabilized after indication for ventilatory support, HFNT and NIV have similar effects on diaphragmatic work per breath, but high-flow therapy confers additional physiological benefits by decreasing respiratory rate and minute ventilation.Clinical trial registrationEthics Committee of St. Michael’s Hospital (REB #14-338) and clinicaltrial.gov (NCT02262871).Electronic supplementary materialThe online version of this article (10.1186/s13613-018-0432-4) contains supplementary material, which is available to authorized users.

High-Flow Nasal Cannula in Early Emergency Department Management of Acute Hypercapnic Respiratory Failure Due to Cardiogenic Pulmonary Edema

“…36 No effects were observed on transcutaneous CO 2 in this physiologic study, which included 15 subjects ventilated with HFNC and NIV for 30 min in a cross-over random order, which was probably due to the short duration of HFNC treatment. 37 NIV seemed to have a greater effect on breathing frequency than HFNC in our subjects. We assumed that NIV combined the effect of pressure support and high PEEP to improve breathing frequency more quickly than HFNC, for which PEEP is limited, especially when suboptimal nasal flow was administered (ie, < 60 L/min) or when the mouth of the patient was open.…”

Usefulness of Parasternal Intercostal Muscle Ultrasound during Weaning from Mechanical Ventilation

“…For Study B, Friedman test and Dunn multiple comparisons were used to compare the different values of parasternal intercostal muscle thickening and diaphragm thickening fraction across conditions. Sample size was estimated from previous publications 17,20 and a convenience sample of 16 patients was deemed necessary.…”

Physiopathological rationale of using high-flow nasal therapy in the acute and chronic setting: A narrative review

“…In stabilized patients with Cystic Fibrosis, no differences in work of breathing as measured by diaphragmatic activity were observed while patients were at baseline, on HFNT or on NIV. However, HFNT resulted in mild improvement in VT compared to NIV and reduced RR compared to COT [94].…”

“…Interestingly long-term studies have shown that HFNT is well tolerated, and reduces dyspnea compared to LTOT [41, 42], but when used in the short-term HFNT does not provide similar results in patients with COPD or CF [90,91,94]. Despite the lack of side effects, patients have reported overall comfort to be better or similar on LTOT and NIV compared to HFNT the delivered flow was 30 L/min [101].…”