Diabetic ketoacidosis (DKA) secondary to selective renal sodium-glucose cotransporter 2 inhibitor (SGLT2i) use is a rare but increasingly reported phenomenon. While euglycemic DKA (EuDKA) is typically associated with these medications, hyperglycemic DKA (hDKA) is rare. In the wake of guidelines recommending SGLT2i for patients with other co-morbidities such as heart failure, it is important to evaluate the potential consequences of using these medications. In this report, we describe a patient with long-standing diabetes who started dapagliflozin 3 months prior to admission and developed hyperglycemic DKA with severe complications including cardiac injury, Kussmaul respirations, and metabolic encephalopathy with rapid resolution of symptoms after insulin treatment and discontinuation of SGLT2i.