Knowledge Base Article

Coders probably sometimes feel as if they are searching for the proverbial needle in the haystack. They must evaluate an entire medical record to pick out the key condition responsible for a patient’s admission and other conditions that affect the patient’s treatment. Not easy considering the issues with incomplete, illegible, and conflicting documentation that may be present. And then there are the numerous coding rules of which coders must be aware and stay current. Our hats off to coders everywhere.

Last week, we reviewed the CERT findings from the July 2014 Medicare Compliance Quarterly Newsletter which focused on documentation deficiencies. This week we will look at some coding errors identified by the Recovery Auditors (RACs) detailed in the July Compliance Newsletter. These are brief summaries of the examples given in the newsletter. I encourage everyone to carefully review the examples in the newsletter for complete understanding.

Heart Failure and Shock (MS-DRGs 291, 292 and 293)

The RACs identified errors for these DRGs in both the sequencing of the principal diagnosis and in improper coding of the secondary diagnosis.

• The patient presented with decompensated congestive heart failure (CHF) and a pleural effusion with pulmonary edema. The physician did not state the cause of the pleural effusion so this should be coded as pleural effusion not otherwise specified (NOS) (511.9), instead of pleural effusion not elsewhere classified (NEC) (511.8). Coding Clinic has noted that pulmonary effusions are often seen with CHF with and without pulmonary edema and may be reported as an additional diagnosis. In this case the change in the secondary diagnosis changes the DRG assignment from 291 to 292, resulting in an overpayment.
• In the second example provided, a patient is diagnosed with CHF and an acute myocardial infarction. The reason for admission as determined after study was the acute MI (410.71), not the heart failure (428.20) also changing the DRG assignment to a lower weighted DRG.

NOTE

Medical Management Plus Inpatient Coders offer the following comments concerning pleural effusions with CHF: Coders assume a relationship between pleural effusions and CHF unless stated otherwise. Pleural effusion is considered to be integral to the CHF disease process and will normally clear with treatment for the CHF. It would not typically be assigned its own diagnosis code. Pleural effusions may only be reported as an additional diagnosis if the condition is specifically evaluated or treated, but reporting is not required. Evaluation may involve special x-rays such as decubitus views or diagnostic thoracentesis and it may be necessary to address the effusion by therapeutic thoracentesis or chest tube drainage.

Effective 2009, ICD-9 code 511.8 required a 5th digit and was removed from the MCC list. Both 511.8x and 511.9 are now CCs.

Postoperative or Posttraumatic Infections with Operating Room (OR) Procedure with Complications and Comorbidities (CC) (MS-DRG 857)

Both examples given for this DRG involve improper diagnosis code assignment in cases where the infection and complications were associated with implanted devices and not with the surgical procedure itself. In these examples, code 998.59 (postoperative infections) should not have been assigned as the principal diagnosis code because it excludes infections due to implanted devices.

• The first involved a total knee prosthesis which should have been coded with a principal diagnosis code of 996.66, Infection and inflammatory reaction due to internal prosthetic device implant and graft. The secondary diagnosis code of 998.12, hemorrhage or hematoma complicating a procedure, was replaced with ICD-9 diagnosis code 997.77 other complication due to internal joint prosthesis. This resulted in a DRG change from 857 to 487.
• The second patient was treated surgically for a pocket infection of a pacemaker. A correct principal code assignment of 996.61, Infection and inflammatory reaction due to cardiac device, implant, and graft changed the MS-DRG from DRG 857 to DRG 261.

Amputations (MS-DRGs 239, 240, 241, 474, 475, and 476)

The final inpatient coding errors involved secondary diagnoses coded with amputation DRGs. The code assignments were not supported by the physician documentation for acute heart failure or acute renal failure. Removing or correcting these diagnosis codes removed the MCC resulting in lower weighted DRGs.

Coders have a difficult task of reviewing an entire medical record and selecting the appropriate principal and secondary diagnoses. The principal diagnosis is defined in the Uniform Hospital Discharge Data Set (UHDDS) as "the condition established after study to be chiefly responsible for occasioning the admission of the patient to the hospital for care” but careful consideration must be used in making this determination, such as what was the actual reason for the admission and the focus of treatment. Also, secondary diagnoses must be clearly supported by the physician’s documentation in the medical record and correctly selected based on coding guidelines. Errors in code sequencing and selection can easily lead to an overpayment.