Respiratory depressants among patients undergoing noninvasive ventilation for hypoxemic-hypercapnic acidosis: Prevalence and impact on prognosis

Medical records show frequent psychoactive drug treatments among the elderly with respiratory depression as a potential side effect. We evaluate their impact in patients undergoing noninvasive ventilation (NIV) for acute hypercapnic respiratory failure (AHRF) with acidosis. Methods : Prospective study in 103 consecutive admissions (71 M, age 74,9±9 yrs) starting NIV for AHRF with acidosis in a Monitoring Unit (Oct.08-Jan.12) Two groups based on previous therapy with psychoactive drugs and significant sedative effect. Variables : pH, pO 2 , pCO 2 , pO 2 /FiO 2 at admission(1), 2h of NIV(2) and 24h of NIV(3); in-hospital mortality and combined in-hospital and 30-day post-discharge mortality, length of stay (LOS) and intubation %. We recorded main diagnosis and thoracic comorbidities. Stat. analysis : χ 2 /MWW. Results : 39 pts (37,9%) received sedatives: M 22,5%,F 71,8%; BZDs 89,7%. Main diagnosis (% sedatives): COPD 48 (25%), OHS 20 (55%),Acute heart failure 16 (56,2%), Pneumonia 7 (28,6%), Acute pulmonary edema 6 (66,7%), Chest wall deformities 4 (25%).Comorbidity 55,3%. Group analysis (sedatives vs no sedatives): Sex (M) 41% vs 85,9% (p 2 evolution between groups: pH1 7,27±0,08 vs 7,26±0,59; pH2 7,30±0,09 vs 7,32±0,07; pH3 ≥7,35 (both groups) Conclusions : We found a high prevalence of respiratory depressants in patients with AHRF. Sedatives may worsen prognosis and early response to NIV, especially in elderly female patients without COPD.