Inpatient hospitals are improperly coding coronary bypass with percutaneous transluminal coronary angioplasty (PTCA) with major complications and comorbidities (MCCs) (MS-DRGs 231, 233, and 235), according to the October issue of the Medicare Quarterly Provider Compliance Newsletter.

In its newsletter, the Centers for Medicare & Medicaid Services report that recovery audit contractors (RACs) are adjusting codes and MS-DRGs in order to align provider payments with Medicare guidelines for the presence of diagnoses. Changes are also made to ensure diagnoses are correctly sequenced, coded, and clinically validated.

In its newsletter, CMS gave two case-study examples and explained how RACs resolved the error.

Example 1

A 68-year-old male was admitted for coronary artery bypass graft (CABG) secondary to three-vessel coronary artery disease (CAD). As indicated in the discharge summary and history and physical (H&P), the patient was previously admitted with flash pulmonary edema and ruled in for myocardial infarction (MI). He was treated, optimized, and needed a period at home to take care of some personal business prior to his CABG. He was admitted, and following a CABG, secondary to three-vessel CAD, he was discharged to home.

RAC Finding and Action:

Inpatient hospital coders assigned ICD-9-CM diagnosis code 518.4 (acute edema of lung unspecified), but It was not treated or evaluated and, therefore, it was not actually a current problem. As a result, the RAC deleted code 518.4 for this admission. This condition was treated on the patient's prior admission before discharge.

This change resulted in a change from MS-DRG 235 (coronary bypass without cardiac cath with MCC) to MS-DRG 236 (coronary bypass without cardiac cath without MCC), which resulted in an overpayment.

Example 2

A 43-year-old male was admitted through the emergency department because of chest pain that he was experiencing. He was found to have exertional angina, and he had a positive stress test. The patient was taken to the operating room where he had a two-vessel CABG completed secondary to his CAD. The patient has a history of human immunodeficiency virus (HIV) and is on highly active antiretroviral therapy (HAART). After the CABG procedure, the patient remained on a ventilator for two hours. The patient did not have any history of congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), or asthma.

RAC Finding and Action:

The progress note on post-operative day one stated that there was "no apparent anesthesia-related complications." The anesthesiologist's progress note on post-operative day zero was the only documentation of respiratory failure. No other documentation of respiratory failure is present on the discharge summary or progress notes. Apparently, the anesthesiologist documented a need for the usual mechanical ventilation used during the procedure to continue for two hours after the surgery. However, the attending physician did not document respiratory failure.

The RAC deleted diagnosis code 518.5 (pulmonary insufficiency following trauma and surgery) secondary to this being normal to post-operative recovery. This deletion resulted in a change from MS-DRG 235 (coronary bypass without cardiac cath with MCC) to MS-DRG 236 (coronary bypass without cardiac cath without MCC), which resulted in an overpayment.

Tips on Avoid These Problems

CMS provided the following guidelines on how inpatient hospital coders can avoid the problems described above.

• When a patient is admitted to the hospital, the health condition that (after physician assessment) is determined to be chiefly responsible as the admission cause should be sequenced as the principal diagnosis (coded as an MS-DRG). Review the official coding guidelines for selection of principal diagnoses and chapter-specific guidelines. Refer to Coding Clinics for advice and guidance.

• All medical-documentation entries must be consistent with other parts of the medical record (assessments, treatment plans, physician orders, nursing notes, medication and treatment records, etc.). They also should be consistent with other facility documents such as admission and discharge data and pharmacy records. If an entry is made that contradicts documentation found elsewhere in the record, contact the attending physician to clarify.

• Review the ICD-9-CM Coding Manual and the ICD-9-CM addendums and Coding Clinics about coding guidelines on sequencing and selection of principal diagnosis. Follow coding guidelines and Uniform Hospital Discharge Data Set (UHDDS) definitions of when to code secondary diagnosis and chronic condition. Do not code diagnoses not documented in the record.