Lithium in Cardiac Surgery Related Acute Kidney Injury: A Pilot Study

Cardiac surgery associated acute kidney injury (CSA-AKI) is a significant problem. The prevalence varies from 0.3% to 22.9% depending on the definition of AKI. The pathogenesis of AKI in this population is multifactorial. Factors associated with AKI in such patients include increased age, preoperative elevated creatinine, presence of diabetes, reduced ejection fraction, increased body weight, and presence of carotid artery bruit, duration of cardiopulmonary bypass, aortic cross clamp time, and duration of surgery. CSA-AKI is an independent predictor of mortality, morbidity, increased length of stay and hospitalization costs. Moreover these patients are also at increased risk of chronic kidney disease and end stage renal failure in the future.

Various pharmacologic approaches that have been tried to prevent early CSA-AKI such as diuretics, vasodilators, and anti-inflammatory drugs. Fenoldopam, atrial natriuretic peptide, and brain natriuretic peptide have shown little renoprotection. However these strategies lack high quality evidence to support their use and are not standard of care. There is no strong evidence to suggest any single or multiple pharmacotherapy that significantly impacts in reducing CAS-AKI. Thus the current best therapy for CSA-AKI is prevention, supportive care, hemodynamic optimization and renal replacement therapy.

AKI is an extremely complex process involving multiple pathophysiologic pathways. Glycogen synthase kinase 3β (GSK3β) is implicated in many pathways beyond glycogen metabolism and has been shown to be an important player in the development of AKI . Lithium is a US Food and Drug Administration (FDA)-approved drug which has been used for over 50 years as first line agent to treat mood disorders. It is a standard inhibitor for GSK3β. Latest evidence in murine models of cisplatin-induced AKI and ischemia/reperfusion-induced AKI suggests that lithium treatment may attenuated kidney dysfunction and kidney histologic injury following AKI. Lithium was able to promote kidney tubular cell repair hence improvement of AKI in murine models. In addition, lithium has also been found to exert an anti-proteinuric and renal reparative effect. On this background we want to explore the potential preventive and therapeutic role of lithium carbonate in CSA- AKI.