Chronic obstructive pulmonary disease (COPD) was identified as an independent risk factor for 28-day all-cause mortality in patients with sepsis, according to a study published in BMC Pulmonary Medicine.
The researchers explained that although COPD has been identified as one of the most common comorbidities in patients with sepsis, its impact on patients with sepsis remained unclear, as past studies reported mixed findings. Therefore, the researchers conducted a study to explore the impact of COPD on 28-day all-cause mortality in patients with sepsis. To do so, they used the Medical Information Mart for Intensive Care (MIMIC)-III database version 1.4 (v1.4), which spans from 2008 to 2012; it is comprised of patients 16 years or older admitted to critical care units in the Beth Israel Deaconess Medical Center (BIDMC) in Boston, Massachusetts between 2001 and 2012.
The researchers used the database to extract various records on patients with sepsis. They identified which patients had sepsis through sepsis-3 criteria; those with sepsis had a documented or suspected infection and an acute change in total Sequential Organ Failure Assessment (SOFA) score by 2 or more points. Additionally, the researchers determined which patients with sepsis had COPD by examining their recorded International Classification of Diseases (ICD-9) codes.
A total of 6257 patients with sepsis were included in the study, 955 of whom also had COPD (15.3%); they noted that the number of patients with COPD was consistent with previous studies, which found that between 6.9% and 16.5% of those with sepsis also had COPD. The researchers explained that patients with COPD were older (median, 73.5; IQR, 64.4-82.0 vs median, 65.8; IQR, 52.9-79.1; P < .001) than those without. Patients with COPD also had a greater proportion of mechanical ventilatory support (55.0% vs 48.9%; P = .001) and a higher simplified acute physiology score II (SAPSII) (median, 40.0; IQR, 33.0-49.0 vs median, 38.0; IQR, 29.0-47.0; P < .001).
Patient in hospital
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Overall, patients with both sepsis and COPD had higher 28-day all-cause mortality than those without COPD (23.6% vs 16.4%; P = .001). The researchers noted that COPD was identified as an independent risk factor for the 28-day all-cause mortality of patients with sepsis after adjusting for covariates (HR, 1.30; 95% CI, 1.120-1.50; P = .001).
Also, in comparison with patients without COPD, the researchers found that patients with both sepsis and COPD had higher intensive care unit (ICU) mortality rates (13.5% vs 8.9%; P < .001), longer ICU stays (3.1 days vs 2.9 days; P = .005), and higher in-hospital mortality rates (17.1% vs 12.3%; P < .001).
The researchers acknowledged their study’s limitations, one being that patients with COPD were identified through ICD-9 codes instead of spirometry (post-bronchodilator forced expiratory volume in 1 second/forced vital capacity ratio < .70), which resulted in the overdiagnosis of COPD. Because of their study’s limitations, they noted that further research must be conducted to confirm their findings.
“These findings highlighted the importance of providing specialized care for septic patients with COPD,” the authors concluded. “However, it is crucial to recognize that the association between COPD and higher mortality in septic patients is still hypothetical and requires further investigation through appropriately designed studies.”
Chen, Y., Lu, L., Li, X. et al. Association between chronic obstructive pulmonary disease and 28-day mortality in patients with sepsis: a retrospective study based on the MIMIC-III database. BMC Pulm Med 23, 435 (2023). doi:10.1186/s12890-023-02729-5