CCDS Principal Procedure Selection and MS-DRG 4 — Questions and Answers
Question 1: A patient undergoes coronary artery bypass grafting (CABG) and simultaneous mitral valve repair. Which procedure is designated as the principal procedure for MS-DRG assignment?
- Mitral valve repair, as valvular procedures outrank revascularization
- CABG, as it is listed first in the operative report
- The procedure most closely related to the principal diagnosis or the most resource-intensive procedure (Correct answer)
- Both procedures carry equal weight and are averaged for DRG assignment
Correct answer: The procedure most closely related to the principal diagnosis or the most resource-intensive procedure
The principal procedure is the one most closely related to the principal diagnosis or, when tied, the most resource-intensive procedure performed.
Question 2: Under ICD-10-PCS, which root operation would be coded when a surgeon removes a kidney stone via percutaneous nephrostolithotomy without removing any body part?
- Resection
- Extirpation (Correct answer)
- Excision
- Fragmentation
Correct answer: Extirpation
Extirpation is the root operation for taking or cutting out solid matter (such as a calculus) from a body part without removing the body part itself.
Question 3: A patient admitted for pneumonia also undergoes diagnostic bronchoscopy with bronchoalveolar lavage. Which procedure is the principal procedure?
- Bronchoscopy with BAL, because it is the only procedure performed
- Bronchoscopy with BAL only if it changes the final diagnosis
- There is no principal procedure when only a diagnostic procedure is done
- The procedure directly treating the principal diagnosis (none here, so bronchoscopy by default) (Correct answer)
Correct answer: The procedure directly treating the principal diagnosis (none here, so bronchoscopy by default)
When no therapeutic procedure is performed, the diagnostic procedure most related to the principal diagnosis is designated the principal procedure.
Question 4: Which MS-DRG grouping logic feature allows a single DRG to shift to a higher-weighted DRG when a qualifying OR procedure is present?
- CC/MCC subclassification
- MDC assignment
- OR procedure designation (Correct answer)
- Procedure intensity scoring
Correct answer: OR procedure designation
OR (operating room) procedure designation triggers MS-DRG logic to route a case to surgical DRGs, which typically carry higher relative weights than medical DRGs.
Question 5: A CDS queries about the approach for a laparoscopic appendectomy converted to open. Which ICD-10-PCS approach character should be reported?
- Percutaneous endoscopic (4), reflecting the attempted approach
- Open (0), reflecting the completed approach (Correct answer)
- External (X), since the body wall was ultimately opened
- Via natural or artificial opening endoscopic (8)
Correct answer: Open (0), reflecting the completed approach
ICD-10-PCS guidelines state that when a laparoscopic procedure is converted to open, the open approach (0) is coded because that is how the procedure was completed.
Question 6: Which of the following best describes the 'non-OR procedure affecting MS-DRG assignment' designation?
- Procedures performed outside the OR that are ignored by the grouper
- Procedures not performed in an OR that nonetheless shift the MS-DRG when coded (Correct answer)
- Procedures that always reduce the MS-DRG weight
- Procedures coded only when they occur in an ambulatory surgery center
Correct answer: Procedures not performed in an OR that nonetheless shift the MS-DRG when coded
Non-OR procedures affecting MS-DRG assignment are bedside or minor procedures not done in an OR that the grouper still uses to move a case to a different (often higher) DRG.
Question 7: When two surgical procedures are performed and either could serve as the principal procedure, what does the UHDDS guideline recommend?
- Code both and let the grouper decide automatically
- Select the procedure with the higher relative weight
- The facility may sequence them in any order, and the grouper selects the DRG with the highest weight (Correct answer)
- Always select the procedure with the longer operative time
Correct answer: The facility may sequence them in any order, and the grouper selects the DRG with the highest weight
UHDDS guidelines allow facilities to sequence multiple qualifying procedures in any order; the MS-DRG grouper evaluates all coded procedures and assigns the DRG that results in the highest relative weight.
CCDS Principal Procedure Selection and MS-DRG 4
A patient undergoes coronary artery bypass grafting (CABG) and simultaneous mitral valve repair.
Which procedure is designated as the principal procedure for MS-DRG assignment?