Obesity is associated with bilevel non-invasive ventilation (NIV) failure and intensive care unit (ICU) admissions in patients with chronic obstructive pulmonary disease (COPD) exacerbations, according to research presented at the CHEST Annual Meeting 2019.
This single-center, longitudinal, retrospective cohort study included all patients admitted to a community hospital with the primary diagnosis of COPD exacerbation between June 2017 and June 2018. Patients who did not require bilevel NIV during their stay or had a do not resuscitate order at admission were excluded.
A total of 100 patients were included and categorized as obese (body mass index [BMI] ≥30 kg/m2; n=42; mean age, 63.0 years) or non-obese (BMI <30 kg/m2; n=58; mean age, 67.2 years). In each group, 35.7% and 58.6%, respectively, were active smokers.
Bilevel NIV failure occurred in eight obese patients (19%) and one non-obese patient (1.7%; relative risk, 2.37; 95% confidence interval, 1.67-3.38; P<0.01). ICU visits occurred in 28.6% of the obese population and 8.6% of the non-obese population (P=0.014). The average ICU length of stay (LOS) was 12.4 days in obese patients and 3.4 days in non-obese patients. The average hospital LOS was 12.1 days and 6.7 days, respectively (P=0.235). Thirty-day readmission rates were 17.5% among obese patients and 21.1% among non-obese patients.
“Identifying patients at higher risk of bilevel NIV failure will improve outcomes by enabling closer monitoring and early escalation of care,” the researchers noted. “Mechanical effects of obesity on respiratory physiology such as decreased pulmonary compliance and a decrease in functional residual capacity below the closing capacity of small airways can result in atelectasis; a possible explanation for the high rates of bilevel NIV failure we found in our study.”
Zeba F, Assali M, McGovern R, et al. Effect of obesity on outcomes in patients with COPD exacerbation requiring bi-level noninvasive ventilation. Presented at the CHEST Annual Meeting 2019. October 19-23, 2019; New Orleans, Louisiana.