Outcomes of Noninvasive and Invasive Ventilation in Patients Hospitalized with Asthma Exacerbation

Abstract

Rationale: Little is known about the effectiveness of noninvasive ventilation for patients hospitalized with asthma exacerbation.Objectives: To assess clinical outcomes of noninvasive (NIV) and invasive mechanical ventilation (IMV) and examine predictors for NIV use in patients hospitalized with asthma.Methods: This was a retrospective cohort study at 97 U.S. hospitals using an electronic medical record database. We developed a hierarchical regression model to identify factors associated with the choice of initial ventilation and used the Laboratory Acute Physiological Score to adjust for differences in the severity of illness. We assessed the outcomes of patients treated with initial NIV or IMV in a propensity-matched cohort.Measurements and Main Results: Among 13,930 subjects, 73% were women and 54% were white. The median age was 53 years. Overall, 1,254 patients (9%) required ventilatory support (NIV or IMV). NIV was the initial ventilation method for 556 patients (4.0%) and IMV for 668 (5.0%). Twenty-six patients (4.7% of patients treated with NIV) had to be intubated (NIV failure). The in-hospital mortality was 0.2, 2.3, 14.5, and 15.4%, and the median length of stay was 2.9, 4.1, 6.7, and 10.9 days among those not ventilated, ventilated with NIV, ventilated with IMV, and with NIV failure, respectively. Older patients were more likely to receive NIV (odds ratio, 1.06 per 5 yr; 95% confidence interval [CI], 1.01-1.11), whereas those with higher acuity (Laboratory Acute Physiological Score per 5 units: odds ratio, 0.85; 95% CI, 0.82-0.88) and those with concomitant pneumonia were less likely to receive NIV. In a propensity-matched sample, NIV was associated with a lower inpatient risk of dying (risk ratio, 0.12; 95% CI, 0.03-0.51) and shorter lengths of stay (4.3 d less; 95% CI, 2.9-5.8) than IMV.Conclusions: Among patients hospitalized with asthma exacerbation and requiring ventilatory support (NIV or IMV), more than 40% received NIV. Although patients successfully treated with NIV appear to have better outcomes than those treated with IMV, the low rate of NIV failure suggests that NIV was being used selectively in a lower risk group. The increased risk of mortality for patients who fail NIV highlights the need for careful monitoring to avoid possible delay in intubation.

Non‐invasive ventilation use in status asthmaticus: 16 years of experience in a tertiary intensive care

“…21,22 However, an American database study had similar LOS for their NIV patients of 4.1 days. 15 Our blood gas data was consistent with severe asthma and the median pH is lower than other studies. 21,26 Previous studies have also shown that NIV is effective in decreasing arterial carbon dioxide in severe asthma and can be as effective as IMV.…”

“…Our failure rate for NIV was 4.5%, similar to a large American retrospective cohort from an electronic medical record database but less than other studies . Leatherman reports a failure rate of 17% across five studies .…”

“…Our study shows shorter CCC and hospital LOS than most published international data . However, an American database study had similar LOS for their NIV patients of 4.1 days …”

“…The Cochrane review in 2012 highlighted this paucity of evidence and advised there was no basis for a change in practice based on the current research . Despite this, there is increasing clinical use and this study seeks to add to the reported experience of using NIV as part of the treatment for severe asthma . This paper reports on all asthma admissions admitted to the Critical Care Complex (CCC) at Middlemore Hospital (MMH) between 2000 and 2015 with a focus on the use of NIV.…”

Official ERS/ATS clinical practice guidelines: noninvasive ventilation for acute respiratory failure

“…In a recent retrospective cohort study [59] conducted in 97 US hospitals during a 4-year period, the use of NIV in patients with acute asthma was 4% (556 out of 13 930) and the use of invasive ventilation was 5% (668 out of 13 930). Failure rate (defined as intubation) of NIV was 4.7% (26 patients).…”