Outcomes of noninvasive ventilation for acute exacerbations of chronic obstructive pulmonary disease in the United States, 1998-2008

Abstract

Rationale: The patterns and outcomes of noninvasive, positive-pressure ventilation (NIPPV) use in patients hospitalized for acute exacerbations of chronic obstructive pulmonary disease (COPD) nationwide are unknown.

Objectives: To determine the prevalence and trends of noninvasive ventilation for acute COPD.

Methods: We used data from the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample to assess the pattern and outcomes of NIPPV use for acute exacerbations of COPD from 1998 to 2008.

Measurements and main results: An estimated 7,511,267 admissions for acute exacerbations occurred from 1998 to 2008. There was a 462% increase in NIPPV use (from 1.0 to 4.5% of all admissions) and a 42% decline in invasive mechanical ventilation (IMV) use (from 6.0 to 3.5% of all admissions) during these years. This was accompanied by an increase in the size of a small cohort of patients requiring transition from NIPPV to IMV. In-hospital mortality in this group appeared to be worsening over time. By 2008, these patients had a high mortality rate (29.3%), which represented 61% higher odds of death compared with patients directly placed on IMV (95% confidence interval, 24-109%) and 677% greater odds of death compared with patients treated with NIPPV alone (95% confidence interval, 475-948%). With the exception of patients transitioned from NIPPV to IMV, in-hospital outcomes were favorable and improved steadily year by year.

Conclusions: The use of NIPPV has increased significantly over time among patients hospitalized for acute exacerbations of COPD, whereas the need for intubation and in-hospital mortality has declined. However, the rising mortality rate in a small but expanding group of patients requiring invasive mechanical ventilation after treatment with noninvasive ventilation needs further investigation.

Figure 1.

Temporal trends in the use of noninvasive positive pressure ventilation (NIPPV) and invasive mechanical ventilation (IMV) as the initial form of respiratory support in patients hospitalized with acute exacerbations of chronic obstructive pulmonary disease (COPD) in the United States, 1998–2008.

Figure 2.

Proportion of patients treated with noninvasive positive pressure ventilation (NIPPV), invasive mechanical ventilation (IMV), or without respiratory support for acute exacerbation of chronic obstructive pulmonary disease in the United States during 1998–2008 who were over 75 years of age.

Figure 3.

In-hospital mortality among all comers (patients not requiring respiratory support, patients treated with invasive mechanical ventilation [IMV], and patients treated with noninvasive positive pressure ventilation [NIPPV]) with and without the need for subsequent transition to IMV for acute exacerbations of chronic obstructive pulmonary disease in the United States, 1998–2008. The P values for trend in mortality among all the different groups included in the figure were statistically significant (P < 0.01).

Figure 4.

The number of patients and the number of in-hospital deaths among patients requiring transition from noninvasive positive pressure ventilation (NIPPV) to invasive mechanical ventilation (IMV) after admission for acute exacerbation of chronic obstructive pulmonary disease, 1998–2008.

Figure 5.

Proportion of those who survived or died after treatment with noninvasive positive pressure ventilation (NIPPV) with and without the need for subsequent transition to invasive mechanical ventilation (IMV) due to acute exacerbations of chronic obstructive pulmonary disease during 1998–2008 who were older than 75 years of age.

Figure 6.

Multivariable analysis of in-hospital mortality compared with primary invasive mechanical ventilation (IMV) among patients treated with noninvasive positive pressure ventilation (NIPPV) with and without subsequent transition to IMV for acute exacerbation of chronic obstructive pulmonary disease, 1998–2008. Multivariate analyses are adjusted for sex, age group, income, payor, hospital region, hospital location and teaching status, and the presence of each comorbidity listed in Table 1.

Figure 7.

Charges for hospitalization for acute exacerbation of chronic obstructive pulmonary disease grouped by type or respiratory support used, 1998–2008. IMV = invasive mechanical ventilation; NIPPV = noninvasive positive pressure ventilation.

Figure 8.

Length-of-stay in days for patients admitted with acute exacerbations of chronic obstructive pulmonary disease grouped by type or respiratory support used during the hospitalization, 1998–2008. IMV = invasive mechanical ventilation; NIPPV = noninvasive positive pressure ventilation.