Discussion
atelectasis, pulmonary edema, postextubation respiratory failure, RCC, NRS
ATELECTASIS, PULMONARY EDEMA, RCC
The results of this RCT indicate that patients with PMV who undergo HFNC have a higher intubation rate than do those who receive NIPPV. All the patients in this study had been receiving mechanical ventilation for more than 2 weeks (30 and 26 days on average in the NIPPV and HFNC groups, respectively). A total of 25% of the patients in the HFNC group required reintubation, whereas none of the patients in the NIPPV group were reintubated (Fig. One minus Kaplan–Meier curves for reintubation in the NIPPV and HFNC groups during the 90-h follow-up period. NIPPV: noninvasive positive-pressure ventilation; HFNC: high-flow nasal cannula.The mechanisms by which NIPPV has benefits to reduce reintubation rates include the following: (1) positive airway pressure can increase intrathoracic pressure, decreasing right ventricular preload and afterload; (2) adequate level of positive end-expiratory pressure (PEEP) increases functional residual capacity and prevents alveolar atelectasis; and (3) positive airway pressure can counterbalance hydrostatic forces leading to pulmonary edema and can help maintain airway patencyThe Acute Physiology and Chronic Health Evaluation II scores of most patients in the present study were ≥ 12 on the day of extubation. Several risk factors for reintubation have been identified, and these factors may vary by the cause of reintubationThe groups’ average length of hospital and RCC stay and time to liberation from NRS were comparable. The in-RCC mortality, in-hospital mortality rates and numbers of ventilator-free days were similar between the groups. Although the morbidity and mortality risks related to reintubation could not be determined in the present study, reintubatation with or without side effects is a preferable outcome to mortality.This study has several limitations. First, the patients and attending teams could not be blinded because of the nature of the treatments. The researchers were excluded from clinical decisions to minimize bias; however, completely eliminating bias was impossible. Second, the NIPPV provided a higher level of PEEP than did the HFNC. Because we did not measure the actual FiOLarger prospective RCTs on this topic should be conducted in the future. Although HFNC is increasingly being used often as a form of postextubation NRS, HFNC may not be as effective as NIPPV in preventing reintubation among patients who have been receiving PMV for at least 2 weeks. NIPPV may be used as rescue therapy for patients receiving PMV who experience postextubation respiratory failure after receiving HFNC alone. Additional studies evaluating HFNC as an alternative to NIPPV for patients receiving PMV are warranted.