Gas composition and pressure in the hypopharynx during high-flow oxygen therapy through a nasal cannula in healthy volunteers with different breathing patterns.

Background: High-flow nasal cannula is widespread in patients with hypoxemic and hypercapnic respiratory failure, but physiological data concerning influence of the combination of breathing pattern, preset flow rate (PFR), and inspiratory oxygen fraction (FO) on end-expiratory pressure (EEP), capnogram, oxygram, and exhaled tidal volume (VTe) remains insufficient.

Methods: The study included 20 healthy subjects with 12 combinations of PFR (30-60-80 L/min) and FO (40-60-80-100%) multiplied by 4 breathing patterns: mouth closed (CM), mouth open (OM), and combination of the CM and OM with hyperpnea (HCM and HOM). Pressure, capnogram, oxygram were measured from hypopharyngeal catheter, VTe, and subject's comfort were assessed.

Predictors of Suboptimal Peak Inspiratory Flow in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease in Clinical Practice.

Background: Incorrect inhalation technique is a primary cause of therapeutic failure in chronic obstructive pulmonary disease (COPD), leading to increased exacerbation frequency. Identifying predictors of suboptimal peak inspiratory flow (sPIF) can significantly enhance treatment efficacy in COPD patients. The objective of this study was to identify the prevalence and predictors of sPIF in hospitalized patients with acute exacerbation of COPD in a clinical setting.