Appeal type: Inpatient Hospital
Decision: Unfavorable

We decided that the Plan does not have to pay for the inpatient stay with DRG value 242 provided from March
8, 2020, to March 10, 2020.

You asked the Plan to pay for the inpatient stay with DRG value 242. You say that the medical records support
the billing of the secondary diagnosis code N17.0 with DRG 242. The Plan denied your request. The Plan says
the medical records do not support the billing of the secondary diagnosis code N17.0 with DRG 242.

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.

In this case, you billed the inpatient services provided with secondary diagnosis code, N17.0, defined as acute
kidney failure with tubular necrosis. 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 the
inpatient stay with DRG value 242. Our reviewer says that the medical records do not support the billing of the
secondary diagnosis code N17.0 with DRG 242. Our physician reviewer found the documentation indicates
that the member was brought in by EMS with a complete heart block with heart rate of 29-37. The enrollee
reportedly was staying in bed all day today and sleeping whereas he is normally very active. He took his blood
pressure at home and noticed the pulse reading was very low; his daughter manually took his pulse and noted
the pulse to be 30 bpm and she called EMS. The enrollee's only complaint was feeling general lethargy and
tiredness. Differentiation from prerenal azotemia, is based mainly on laboratory findings and in the case of
blood or fluid loss, response to volume expansion. Acute tubular necrosis is suspected when serum creatinine
rises greater than .3 above baseline, or a 1.5-2.0 fold in serum creatinine from baseline after an apparent trigger
like hypotensive event, exposure to a nephrotoxin. The rise in creatinine may occur 1 to 2 days after exposure
i.e.: radio contrast or aminoglycosides. ATN must be differentiated from prerenal azotemia because treatment
differs. In prerenal azotemia, renal perfusion is decreased enough to elevate serum blood urea nitrogen or BUN
out of proportion to creatinine, but not enough to cause ischemic damage to tubular cells. Prerenal azotemia can
be caused by direct intravascular fluid loss, like hemorrhage, GI tract losses or urinary losses or by a relative
decrease in effective circulation volume without loss of body fluid as in heart failure, portal hypertension with
ascites. If fluid loss is the cause, volume expansion using IV normal saline increases urine output and
normalizes serum creatinine. If ATN is the cause, IV normal saline typically causes no increase in urine output
and no rapid change in serum creatine. Untreated prerenal azotemia may progress to ischemic ATN. Clinically
this was not supported, and from a compliance standpoint there was not enough additional documentation
provided for this 2-day admission. The review has determined that the records do not support the billing of
DRG 242 with secondary diagnosis code N17.0.

We looked at this physician's review, the file, and Medicare rules. Based on this information, we decided the
medical records do not substantiate the DRG as billed. Therefore, we decided that the Plan does not have to pay
for the inpatient stay with DRG value 242 provided from March 8, 2020, to March 10, 2020.