Appeal type: Inpatient Hospital
Decision: Unfavorable

 
We decided that the Plan does not have to pay for inpatient hospital care provided from January 12, 2021, to 
January 20, 2021, as billed with Diagnosis Related Group (DRG) 637. 
 
You asked the Plan to pay for inpatient care as billed with DRG 637. You say that these services were 
medically necessary and are supported in the record. The Plan denied your request. The Plan says DRG 637 is not appropriate as the diagnosis of metabolic encephalopathy (G93.41) is not supported in the medical record. 
The Plan argues that DRG 638 is more appropriate in this case. 
 
The Plan must follow Medicare rules. Medicare rules say that providers must report services correctly. 
Providers must report inpatient hospital services with the appropriate DRG, which is based, in part, on the 
reported principal and secondary diagnosis codes. 
 
We asked our physician reviewer to carefully review the case file and apply the relevant Medicare rules to 
determine if the Plan was correct in denying the request to pay for inpatient care as billed with DRG 637. Our 
reviewer says that the diagnosis of metabolic encephalopathy (G93.41) is not supported in the medical record 
for this inpatient admission. Our physician reviewer found that the enrollee presented to the facility due to 
complaints of fluctuating blood glucose levels. The enrollee had a past medical history of skin cancer, 
hypertension, diabetes mellitus, and dementia. The physician described the enrollee as "awake and interactive" 
at the time of arrival to the emergency room, and initial serum glucose was noted to be 52. The enrollee was 
treated with IV glucagon. The history and physical indicated that the enrollee was alert and stated that "Mental 
status is at baseline". Progress notes on January 14, 2021, listed a diagnosis of acute encephalopathy, likely 
metabolic in the setting of hypoglycemia and stated that the encephalopathy was resolved. Review of the 
physical exam on this day noted the enrollee to be somnolent, lethargic, and oriented to person only. While 
additional progress notes stated the enrollee was alert and oriented to person, place, and time, patients with 
dementia can experience transient, and episodic mental status fluctuation. When a significant alteration of 
mental status occurs in an enrollee with dementia, and systemic toxic or metabolic factors are present, the 
diagnosis of encephalopathy can only be validated when the enrollees mental status returns to baseline as these 
abnormalities are corrected. Review of the discharge summary revealed that the enrollee remained sleepy but 
arousable. Nursing notes on January 17, 2021, described the enrollee as oriented to person only. Nursing notes 
on the day of discharge also indicated the enrollee was drowsy, would respond to voice, and was oriented to 
person and place only. The enrollee experienced fluctuation in mental status throughout the admission which is 
consistent with her underlying dementia. The review has determined that the medical records did not support 
the billing of metabolic encephalopathy (G93.41). 
 
We looked at this physician's review, the file, and Medicare rules. Based on this information, we decided that 
Medicare rules for coverage of inpatient care as billed with DRG 637 have not been met. Therefore, we 
decided that the Plan does not have to pay for inpatient hospital care provided from January 12, 2021, to 
January 20, 2021, as billed with Diagnosis Related Group (DRG) 637.