Post-operative hypotension after cardiac surgery is associated with acute kidney injury.

Abstract

ObjectivesTo describe the incidence of post-operative hypotension in patients undergoing cardiac surgery during the first 12 hours in ICU and any relationship between hypotension and the development of acute kidney injury (AKI). DesignRetrospective, observational cohort study. SettingSingle centre tertiary teaching hospital in London, UK. Participants100 adult patients who underwent elective cardiac surgery requiring intra-operative cardiopulmonary bypass between May 2021 and November 2021. InterventionsNone. Measurements and Main ResultsA hypotensive event was defined as mean arterial pressure < 65 mmHg of at least 1 minute in duration. Invasive blood pressure data was analysed for the first 12 hours after the surgery and any association between post-operative hypotension and AKI was assessed. 91% of patients experienced hypotension in the first 12 hours post-procedure. On average, a patient would experience 9 hypotensive events, with an event lasting for an average of 5 minutes. 16 patients (16%) developed at least stage 1 AKI. The average duration of hypotension was significantly higher in the AKI group (4.6 min [3.3, 8.0] vs 8.1 min [5.2, 14.2], p=0.029). Those suffering an AKI had a longer ICU and hospital length of stay. ConclusionsThis study has demonstrated that hypotension in the first 12 hours after cardiac surgery is common and that prolonged hypotensive events are associated with developing an acute kidney injury. This emphasises the importance of treating hypotension aggressively and highlights a target for further research and intervention.