Noninvasive Ventilation Use in Critically Ill Patients with Acute Asthma Exacerbations

Abstract

Rationale: Noninvasive ventilation decreases the need for invasive mechanical ventilation and mortality among patients with chronic obstructive pulmonary disease but has not been well studied in asthma.Objectives: To assess the association between noninvasive ventilation and subsequent need for invasive mechanical ventilation and in-hospital mortality among patients admitted with asthma exacerbation to the ICU.Methods: We performed a retrospective cohort study using administrative data collected during 2010-2017 from 682 hospitals in the United States. Outcomes included receipt of invasive mechanical ventilation and in-hospital mortality. Generalized estimating equations, propensity-matched models, and marginal structural models were used to assess the association between noninvasive ventilation and outcomes.Measurements and Main Results: The study population included 53,654 participants with asthma exacerbation. During the study period, 13,540 patients received noninvasive ventilation (25.2%; 95% confidence interval [CI], 24.9-25.6%), 14,498 underwent invasive mechanical ventilation (27.0%; 95% CI, 26.7-27.4%), and 1,291 died (2.4%; 95% CI, 2.3-2.5%). Among those receiving noninvasive ventilation, 3,013 patients (22.3%; 95% CI, 21.6-23.0%) required invasive mechanical ventilation after first receiving noninvasive ventilation, 136 of whom died (4.5%; 95% CI, 3.8-5.3%). Across all models, the use of noninvasive ventilation was associated with a lower odds of receiving invasive mechanical ventilation (adjusted generalized estimating equation odds ratio, 0.36; 95% CI, 0.32-0.40) and in-hospital mortality (odds ratio, 0.48; 95% CI 0.40-0.58). Those who received noninvasive ventilation before invasive mechanical ventilation were more likely to have comorbid pneumonia and severe sepsis.Conclusions: Noninvasive ventilation use during asthma exacerbation was associated with improved outcomes but should be used cautiously with acute comorbid conditions.

Keywords: continuous positive airway pressure; critical care outcomes; mechanical ventilators; respiratory insufficiency; retrospective studies.

Figure 1.

Patient selection criteria. COPD = chronic obstructive pulmonary disease; NIV = noninvasive ventilation.

Figure 2.

Trends in noninvasive ventilation (NIV), invasive mechanical ventilation (IMV), and in-hospital mortality over time. (A) Cochrane-Armitage test for trend: NIV P < 0.0001, IMV P = 0.61, in-hospital mortality P = 0.0003. (B) Cochrane-Armitage test for trend: no intervention P < 0.0001, NIV only P < 0.0001, IMV only P = 0.0007, and NIV followed by IMV P < 0.0001. (C) Cochrane-Armitage test for trend: NIV P < 0.0001, IMV P = 0.02, in-hospital mortality P = 0.09. (D) Cochrane-Armitage test for trend: no intervention P < 0.0001, NIV only P < 0.0001, IMV only P = 0.87, and NIV followed by IMV P < 0.0001. (E) Cochrane-Armitage test for trend: NIV P < 0.0001, IMV P < 0.0001, in-hospital mortality P = 0.33. (F) Cochrane-Armitage test for trend: no intervention P < 0.0001, NIV only P < 0.0001, IMV only P < 0.0001, and NIV followed by IMV P < 0.0001.

Figure 3.

Associations between noninvasive ventilation and subsequent invasive mechanical ventilation and mortality among patients admitted with asthma exacerbation to the ICU. Generalized estimating equation (GEE) and marginal structural models N = 53,654. Propensity-matched models n = 25,450. GEE covariate adjusted included age, sex, race, marital status, primary insurance, admission year and quarter, primary admitting diagnosis of asthma, primary admitting diagnosis of respiratory failure, Elixhauser comorbidity score, hypertension, diabetes, hypothyroidism, obesity, right heart failure, valvular disease, psychoses, alcohol abuse, sleep apnea, weight loss, solid tumor, drug abuse, pulmonary circulation disease, tobacco use, pneumonia, severe sepsis, quartile of hospital beds, population served, teaching hospital, geographic region, attending specialty, and the following early treatments and tests: magnesium, inhaled corticosteroid, inhaled long-acting β-agonist, antibiotics, spirometry, and arterial blood gas. The propensity-matched model with unbalanced covariates included right heart failure, valvular disease, pulmonary circulation disease, solid tumor, psychosis, end-stage renal disease, cirrhosis, and arterial blood gas. Marginal structural model: time-varying confounder included in stabilized inverse probability of treatment weights included administration of magnesium, antibiotics, inhaled corticosteroid, spirometry or peak flow measurement, arterial blood gas, and exposure to noninvasive ventilation in the days prior in addition to baseline covariates included in the GEE covariate-adjusted model.