Appeal type: Medical necessity
Decision: Upheld

Diagnosis:  Acute Kidney Injury.
Treatment:  Inpatient Hospital Stay.
The insurer denied the Inpatient Hospital Stay.  The determination is upheld.

This patient with a past medical history significant for hypertension, diabetes mellitus Type 2, and asthma presented to the emergency department with complaints of abdominal pain that was associated with nausea, vomiting, and loose stool.  Her symptoms had been going on for one week.  The abdominal pain was periumbilical, intermittent.  Her last bowel movement was one day before her presentation.  The patient also complained of intermittent lightheadedness, with two episodes of ground-level collapse without loss of consciousness or prodromal symptoms.  When seen by the admitting physician, the patient denied a fever, chills, upper respiratory infection symptoms, urinary complaints, changes in urine output, chest pain, shortness of breath. She denied recent sick contacts, travel, or recent antibiotic use.

Laboratory evaluation revealed that white blood cell count was 10.1, hemoglobin 14.3, hematocrit 42.7, and platelets 283. The sodium was 138, potassium 3.3, chloride 97, bicarbonate 29, blood urea nitrogen (BUN) 51.3, and creatinine 2.33. The urinalysis was unremarkable.

A computed tomography (CT) scan of the abdomen and pelvis demonstrated no acute disease within the abdomen and pelvis.  The abdominal sonogram showed no evidence of gallstones.  The patient had hydronephrosis of the right kidney, as well as changes consistent with chronic medical renal disease.  The patient was admitted to the hospital with a diagnosis of acute gastroenteritis, acute kidney injury, diabetes mellitus type 2, asthma.

Acute kidney injury was attributed to dehydration due to gastroenteritis, which manifested in vomiting and diarrhea.  The patient received treatment with intravenous fluids and potassium supplements.  She was diagnosed with severe dehydration.  Another clinical diagnosis was mild hypokalemia.  The admitting physician stated that hypokalemia was asymptomatic.

In the hospital, the patient was seen by a gastroenterologist, who diagnosed her with acute gastroenteritis, which was improving.  The gastroenterologist reviewed the imaging studies and confirmed that there was no acute disease within the abdomen and pelvis.  It was recommended to follow up with a gastroenterologist in the clinic and get esophagogastroduodenoscopy (EGD) after discharge.

As a result of the treatment in the hospital, the patient's clinical condition significantly improved.  This included a significant improvement in kidney function.  Reportedly, the blood urea nitrogen (BUN) went down to 23.2 and the creatinine went down to 1.4.  Since the patient's clinical condition significantly improved, she was discharged from the hospital.  At issue is the medical necessity of an inpatient stay.

The requested health service/treatment of inpatient stay was not medically necessary.  This patient presented to the hospital with an acute kidney injury that was related to dehydration due to acute gastroenteritis.  According to the patient's history, she was appropriately diagnosed with acute gastroenteritis.  "Gastroenteritis is inflammation of the lining of the stomach and small and large intestines.  Most cases are infectious, although gastroenteritis may occur after ingestion of drugs and chemical toxins."  The general principles of treatment of acute gastroenteritis include oral or intravenous rehydration, supportive care.  In this clinical case, the patient developed an acute kidney injury as a result of dehydration due to persistent nausea, vomiting, and diarrhea.  Therefore, the patient was appropriately started on intravenous fluids, and her dehydration resolved within one day of the hospitalization.

Her acute kidney injury also significantly improved as a result of the administration of intravenous fluids.  Since the patient's clinical condition improved, including resolution of nausea, vomiting, and diarrhea, the treatment with intravenous fluids was discontinued, and the patient was sent home.  Another contributing factor for acute kidney injury was the use of Lasix, which was discontinued.

Even though she had some hydronephrosis based on the results of the ultrasound, the chronicity of this condition was not established, and the role of hydronephrosis in the acute kidney failure was unclear.  The baseline kidney function was also unclear in this case.

While in the hospital, the patient's symptoms significantly improved, including the resolution of vomiting and diarrhea.  The patient was adequately hydrated.  As a result, the acute kidney injury significantly improved, and the patient was deemed stable for discharge the very next day after the day of admission.  During the hospital stay, there were no procedures or diagnostic tests performed, which would necessitate admission at the acute inpatient level of care.

Care to insure improving oral intake, administer intravenous fluids for treatment of acute kidney injury (AKI), and insure improvement in the kidney function could have been provided at a lower level than inpatient.  Taking into consideration that the patient's symptoms resolved very quickly and her laboratory evaluation demonstrated significant improvement in the kidney function, the care could have been provided at a lower level.  Neither the severity of the patient's condition nor the complexity of the services provided rose to the level of acute inpatient care.