Acute Kidney Injury in Internal Medicine Wards During a Period of Wartime Healthcare System Disruption: A Retrospective Cohort Study

Background/Objectives: Acute kidney injury is a frequent complication among patients hospitalized in internal medicine wards and is associated with adverse outcomes. While increased AKI burden has been reported during pandemics, data on AKI during other forms of acute healthcare system disruption, including armed conflict, are limited. We evaluated AKI incidence and outcomes during a period of wartime healthcare system disruption. Methods: We conducted a retrospective single-center cohort study comparing internal medicine hospitalizations during the initiation of the Israel–Gaza war with a corresponding pre-war period in 2022. AKI was identified based on changes in serum creatinine during hospitalization. Clinical characteristics, AKI etiology, hospitalization indication at admission, and in-hospital outcomes were compared between periods. Multivariable regression models assessed the association between year of hospitalization and outcomes, adjusting for sex, comorbidities, admission kidney function, vital signs, and hospitalization indication. Results: AKI occurred in 110 of 2228 hospitalizations in 2022 (4.9%) and in 95 of 1456 hospitalizations in 2023 (6.5%), representing a 32% relative increase during the wartime period (relative risk 1.32, 95% confidence interval 1.03–1.69). Baseline demographics, comorbidity burden, admission vital signs, and kidney function were similar between cohorts. During the wartime period, hospitalizations were less frequently infection-related, and AKI etiology shifted toward a higher proportion of pre-renal and unspecified causes. Patients hospitalized in 2023 more frequently required kidney replacement therapy and were more often discharged with ongoing dialysis or to nursing facilities. After multivariable adjustment, hospitalization during 2023 remained independently associated with less favorable AKI-related outcomes. Conclusions: Wartime healthcare system disruption was associated with higher AKI incidence and less favorable AKI-related outcomes among internal medicine hospitalizations, independent of measured patient-level risk factors. These findings suggest that kidney outcomes may be sensitive to system-level stress during healthcare emergencies and underscore the importance of maintaining AKI prevention, monitoring, and recovery pathways under such conditions.