This is a retrospective, non-randomized review based on the medical records. The institutional review board of the medical center approved the study design. The study population included consecutive patients admitted to Woodhull Medical Center in Brooklyn, NY, diagnosed with hyperkalemia in the period from January 1, 2005- October 31, 2007. Data will be collected by reviewing medical records using either electronic medical recordsas well as physical charts of previously discharged pa-tients admitted with a diagnosis of hyperkalemia in the Medical-Surgical unit including ICU and Telemetry.