Appeal type: Medical necessity
Decision: Overturned

Diagnosis: Genitourinary/Kidney Disorder-Acute Kidney Failure
Treatment: Inpatient hospital stay

The health plan denied the inpatient hospital stay as not medically necessary. 
The reviewer has overturned in whole the health plan's determination of medical necessity.

The patient has a past medical history remarkable for chronic obstructive pulmonary disease (COPD), hypertension, chronic kidney disease, and polysubstance abuse, who was admitted for hyperkalemia and reported deranged kidney function. The patient was admitted for hyperkalemia, acute on chronic kidney disease, and hypertensive emergency. The patient was treated with nifedipine, clonidine and low salt diet. The patient also received kayexalate for hyperkalemia. The patient's creatine was reported as close to his baseline. The patient was evaluated by a nephrologist and a cardiologist. There were no reported signs of volume overload and dialysis was not required. Renal ultrasound revealed bilateral renal parenchymal echogenicity suggesting renal parenchymal disease. The patient's potassium and blood pressure improved, and the patient was subsequently stable for discharge.

The requested health service/treatment of inpatient hospital admission is medically necessary for this patient.
Based on the documentation, the patient was admitted to acute inpatient level of care for acute kidney injury on underlying kidney disease. Additionally, the patient had severe hyperkalemia in the setting of underlying renal disease. Inpatient level of care was necessary for rapid correction of potassium and monitoring of renal function.
Acute kidney Injury (AKI) is defined by an increase in serum creatinine of 0.3 milligrams per deciliter (mg/dl) within 48 hours. In addition to AKI, this patient also has underlying chronic kidney disease (CKD) which is a clear risk factor for AKI and worsened outcomes. AKI is shown to accelerate the progression of CKD and can result in the need for dialysis and is associated with worsened long-term renal outcomes. In this case, the patient was admitted for severe hyperkalemia in a setting of a declining glomerular filtration rate and worsened renal insufficiency. Therefore, the patient was at risk for long term worsened outcomes. This warranted urgent treatment to prevent the deleterious effects of hyperkalemia. Furthermore, the mortality risk is progressively increased in patients with hyperkalemia who also have underlying chronic kidney disease, diabetes, and congestive heart failure. The in-hospital mortality rate was 18% as compared to 4% for patients with normal potassium levels.
Generally speaking, patients with hyperkalemia can be easily treated and transitioned to outpatient settings. However, hyperkalemia is more complicated to treat in patients with advanced CKD because the kidney is the major route of potassium excretion. Not only is potassium excretion reduced, but underlying heart failure, diabetes, and the use of angiotensin- converting enzyme (ACE) - inhibitors such as lisinopril complicate the management even further. As such, significant treatment strategies are necessary to overcome the pathophysiologic effects of the etiologies. This patient's treatment plan necessitated the use of multiple pharmacologic therapies to promote excretion of potassium. The patient's potassium levels were severe enough to cause cardiac abnormalities and warranted inpatient management for rapid correction. Given the patient's comorbidities, advanced CKD, severe hyperkalemia, and the need for urgent treatment interventions, it was reasonable and medically necessary to admit this patient to the acute inpatient level of care.