Published in:
Open Access
01-12-2019 | Non-Invasive Ventilation | Research
Effects of high-flow nasal cannula and non-invasive ventilation on inspiratory effort in hypercapnic patients with chronic obstructive pulmonary disease: a preliminary study
Authors:
Nuttapol Rittayamai, Prapinpa Phuangchoei, Jamsak Tscheikuna, Nattakarn Praphruetkit, Laurent Brochard
Published in:
Annals of Intensive Care
|
Issue 1/2019
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Abstract
Background
Non-invasive ventilation (NIV) is preferred as the initial ventilatory support to treat acute hypercapnic respiratory failure in patients with chronic obstructive pulmonary disease (COPD). High-flow nasal cannula (HFNC) may be an alternative method; however, the effects of HFNC in hypercapnic COPD are not well known. This preliminary study aimed at assessing the physiologic effects of HFNC at different flow rates in hypercapnic COPD and to compare it with NIV.
Methods
A prospective physiologic study enrolled 12 hypercapnic COPD patients who had initially required NIV, and were ventilated with HFNC at flow rates increasing from 10 to 50 L/min for 15 min in each step. The primary outcome was the effort to breathe estimated by a simplified esophageal pressure–time product (sPTPes). The other studied variables were respiratory rate, oxygen saturation (SpO2), and transcutaneous CO2 pressure (PtcCO2).
Results
Before NIV initiation, the median [interquartile range] pH was 7.36 [7.28–7.37] with a PaCO2 of 51 [42–60] mmHg. sPTPes per minute was significantly lower with HFNC at 30 L/min than 10 and 20 L/min (p < 0.001), and did not significantly differ with NIV (median inspiratory/expiratory positive airway pressure of 11 [10–12] and [5–5] cmH2O, respectively). At 50 L/min, sPTPes per minute increased compared to 30 L/min half of the patients. Respiratory rate was lower (p = 0.003) and SpO2 was higher (p = 0.028) with higher flows (30–50 L/min) compared to flow rate of 10 L/min and not different than with NIV. No significant differences in PtcCO2 between NIV and HFNC at different flow rates were observed (p = 0.335).