Delayed but successful response to noninvasive ventilation in COPD patients with acute hypercapnic respiratory failure

Abstract

Malcolm Lemyze,1,2 Quentin Bury,3 Aurélie Guiot,4 Marie Jonard,1,2 Usman Mohammad,2 Nicolas Van Grunderbeeck,5 Gaelle Gasan,1 Didier Thevenin,2 Jihad Mallat2 1Department of Respiratory and Critical Care Medicine, Schaffner Hospital, Lens, 2Intensive Care Unit, Arras Hospital, Arras, 3Respiratory Intermediate Care Unit, Béthune Beuvry Hospital, Béthune, 4Department of Cardiology, Bois Bernard Hospital, Bois Bernard, 5Respiratory Step Down Unit, Schaffner Hospital, Lens, France Background: We evaluated a new noninvasive ventilation (NIV) protocol that allows the pursuit of NIV in the case of persistent severe respiratory acidosis despite a first NIV challenge in COPD patients with acute hypercapnic respiratory failure (AHRF). Patients and methods: A prospective observational multicentric pilot study was conducted in three tertiary hospitals over a 12-month study period. A total of 155 consecutive COPD patients who were admitted for AHRF and treated by NIV were enrolled. Delayed response to NIV was defined as a significant clinical improvement in the first 48 h following NIV initiation despite a persistent severe respiratory acidosis (pH <7.30) after the first 2 h of NIV trial. Results: NIV failed in only 10 patients (6.5%). Delayed responders to NIV (n=83, 53%) exhibited similar nutritional status, comorbidities, functional status, frailty score, dyspnea score, and severity score at admission, compared with early responders (n=62, 40%). Only age (66 vs 70 years in early responders; P=0.03) and encephalopathy score (3 [2–4] vs 3 [2–4] in early responders; P=0.015) were different among the responders. Inhospital mortality did not differ between responders to NIV (n=10, 12% for delayed responders vs n=10, 16% for early responders, P=0.49). A second episode of AHRF occurred in 20 responders (14%), equally distributed among early and delayed responders to NIV (n=9, 14.5% in early responders vs n=11, 13% in delayed responders; P=0.83), with a poor survival rate (n=1, 5%). Conclusion: Most of the COPD patients with AHRF have a successful outcome when NIV is pursued despite a persistent severe respiratory acidosis after the first NIV trial. The outcome of delayed responders is similar to the one of the early responders. On the contrary, the second episode of AHRF during the hospital stay carries a poor prognosis. Keywords: noninvasive ventilation, acute respiratory failure, COPD, hypercapnia, intubation 

Keywords

• noninvasive ventilation
• acute respiratory failure
• chronic obstructive pulmonary disease
• hypercapnia
• intubation