[Risk factors for acute kidney injury in patients with severe community-acquired pneumonia in high-altitude areas]

Objective: To investigate the risk factors associated with acute kidney injury (AKI) in patients with severe community-acquired pneumonia (SCAP) in the Qinghai-Tibet Plateau region. Methods: This prospective observational cohort study consecutively enrolled 162 SCAP patients who were admitted to Lhasa People's Hospital between January 2023 and December 2024. Patients were categorized into AKI and non-AKI groups based on the occurrence of AKI. Demographic charateristics, laboratory indicators, and 30-day survival outcomes were compared between the two groups. Multivariate logistic regression analysis was used to identify independent risk factors for AKI in patients with SCAP. The predictive value of these risk factors for AKI was evaluated using receiver operating characteristic (ROC) curves. Survival curves were generated using the Kaplan-Meier method. Results: Among the 162 SCAP patients, 97 were male and 65 were female, with a median age of 73 (61, 79) years. The cohort comprised 156 (96.3%) Tibetan, 4 (2.5%) Han Chinese, and 2 (1.2%) patients of other ethnicities. Seventy-four patients (45.7%) developed AKI, comprising 48 cases of Stage 1, 15 of Stage 2, and 11 of Stage 3. Compared to patients without AKI, patients with AKI had a higher incidence of unconsciousness, septic shock, and invasive mechanical ventilation, along with lower oxygenation index and left ventricular ejection fraction (LVEF). In contrast, fasting blood glucose, blood urea nitrogen (BUN), N-terminal pro-brain natriuretic peptide (NT-proBNP)levels, CURB65 score, PSI score, APACHE Ⅱ score, SOFA score, in-hospital mortality, and 30-day mortality were all significantly higher in the AKI group(all P<0.05). Multivariate logistic regression analysis showed that septic shock (OR=3.495, 95% CI: 1.326-9.210, P=0.011), oxygenation index <150 mmHg (OR=5.248, 95% CI: 2.094-13.156, P<0.001), BUN≥7 mmol/L (OR=7.254, 95% CI: 2.785-18.893, P<0.001), albumin<30 g/L (OR=3.492, 95% CI: 1.363-8.950, P=0.009), and LVEF<50% (OR=7.442, 95% CI: 1.990-27.883, P=0.003) were independent risk factors for AKI. The combination of these five indicators yielded a sensitivity of 76.8% and a specificity of 85.4% for predicting AKI, with an area under the ROC curve of 0.853(95% CI: 0.786-0.905, P<0.001). The 30-day cumulative survival rate was significantly lower in the AKI group compared to the non-AKI group (P=0.003). Conclusions: Septic shock, decreased oxygenation index, elevated BUN, reduced serum albumin levels, and decreased LVEF are independent risk factors for AKI in patients with SCAP at high altitude. The combination of these five indicators effectively predicts the occurrence of AKI. Moreover, SCAP patients complicated with AKI exhibit a significantly lower 30-day survival rate.