# Impact of Acute Kidney Injury on Mortality Outcomes in Patients Hospitalized for COPD Exacerbation: A National Inpatient Sample Analysis

## TL;DR

This study finds that acute kidney injury in patients hospitalized for COPD exacerbation is linked to higher mortality and worse outcomes.

## Contribution

The study identifies demographic differences and mortality risk factors in COPD exacerbation admissions with and without acute kidney injury using a national database.

## Key findings

- 13.6% of COPD exacerbation patients had acute kidney injury, which was associated with higher mortality.
- Patients with AKI were older, had longer hospital stays, and included fewer females and White patients.
- Comorbidities like hypertension and diabetes were associated with lower mortality in COPD exacerbation patients with AKI.

## Abstract

Background/Objectives: Acute kidney injury (AKI) worsens outcomes in COPD exacerbation (COPDe), yet limited data compare the demographics and mortality risk factors of COPDe admissions with and without AKI. Understanding this association may enhance risk stratification and management strategies. The aim of this study was to identify demographic differences and mortality risk factors in COPDe admissions with and without AKI. Methods: We conducted a retrospective cohort study using the National Inpatient Sample (NIS) from 1 January 2016 to 1 January 2021. Patients aged ≥ 35 years with a history of smoking and a diagnosis of COPDe were included. Patients with CKD stage 5, end-stage kidney disease (ESKD), heart failure decompensation, urinary tract infections, myocardial infarction, alpha-1 antitrypsin deficiency, or active COVID-19 infection were excluded. Baseline demographics were analyzed using descriptive statistics. Multivariate logistic regression analysis was used to measure the odds ratio (OR) of mortality. Statistical analyses were conducted using IBM SPSS Statistics V.30, with statistical significance at p < 0.05. Results: Among 405,845 hospitalized COPDe patients, 13.6% had AKI. These patients were older, had longer hospital stays, and included fewer females and White patients. AKI was associated with significantly higher mortality (OR: 2.417), more frequent acute respiratory failure (OR: 4.559), intubation (OR: 10.262), and vasopressor use (OR: 2.736). CVA, pneumonia, and pulmonary hypertension were significant mortality predictors. Hypertension, CAD, and diabetes were associated with lower mortality. Conclusions: AKI in COPDe admissions is associated with worse outcomes. Protective effects from certain comorbidities may relate to renoprotective medications. Study limitations include coding errors and retrospective design.