CCDS Principal Procedure Selection and MS-DRG 2 — Questions and Answers
Question 1: Under ICD-10-PCS guidelines, which procedure is defined as the 'principal procedure' for DRG grouping purposes?
- The first procedure listed in the operative report
- The procedure most related to the principal diagnosis and most resource-intensive (Correct answer)
- The procedure with the highest ICD-10-PCS relative weight
- The procedure performed by the attending physician, regardless of complexity
Correct answer: The procedure most related to the principal diagnosis and most resource-intensive
The principal procedure is the one most related to the principal diagnosis or the one performed for definitive treatment. When multiple procedures are performed, the one most closely related to the principal diagnosis and involving the most resources is typically selected.
UHDDS and ICD-10-PCS guidelines define the principal procedure as the procedure performed for definitive treatment rather than diagnostic or exploratory purposes, or one that most closely relates to the principal diagnosis. The selection significantly impacts DRG assignment because surgical DRGs often result in higher relative weights than medical DRGs.
Question 2: A patient is admitted with acute appendicitis and undergoes a laparoscopic appendectomy. A second procedure (colonoscopy for incidental polyp removal) is also performed. Which procedure should be designated as principal?
- Colonoscopy, as it is a more complex endoscopic procedure
- Laparoscopic appendectomy, as it directly treats the principal diagnosis (Correct answer)
- Both procedures have equal claim to principal designation
- The procedure performed first in the operating suite
Correct answer: Laparoscopic appendectomy, as it directly treats the principal diagnosis
The laparoscopic appendectomy directly treats acute appendicitis, the principal diagnosis. It should be designated as the principal procedure.
Appendicitis is the principal diagnosis and the laparoscopic appendectomy is the definitive treatment for that condition. Colonoscopy with polypectomy was performed incidentally and would be coded as an additional procedure. Designating the appendectomy as principal results in assignment to a surgical DRG.
Question 3: Which of the following changes to a case would MOST likely result in a shift from a medical MS-DRG to a surgical MS-DRG?
- Adding an MCC-level secondary diagnosis
- Documenting a therapeutic surgical procedure performed during the admission (Correct answer)
- Changing the principal diagnosis to a more specific code
- Documenting additional days of mechanical ventilation
Correct answer: Documenting a therapeutic surgical procedure performed during the admission
When a therapeutic surgical procedure is performed and coded, the MS-DRG grouper typically assigns the case to a surgical DRG, which often carries a higher relative weight than the corresponding medical DRG.
The MS-DRG system organizes cases into medical and surgical DRG partitions. Cases with qualifying O.R. procedures are assigned to surgical DRGs, which generally have higher relative weights reflecting the resource intensity of surgical care.
Question 4: In the MS-DRG system, what is the significance of a 'Major Diagnostic Category' (MDC)?
- It determines the maximum number of secondary diagnoses allowed per claim
- It groups cases by organ system or etiology and is the first-level classification before DRG assignment (Correct answer)
- It is used to calculate the hospital's total CMI across all service lines
- It determines whether a case receives the CC or MCC version of the DRG
Correct answer: It groups cases by organ system or etiology and is the first-level classification before DRG assignment
Major Diagnostic Categories (MDCs) represent the first tier of DRG classification, grouping cases by primary organ system or disease etiology. The DRG grouper uses the MDC as the entry point before assigning a specific DRG.
The MS-DRG grouping logic begins with MDC assignment based on the principal diagnosis. There are 25 MDCs organized by body system or special category. Within each MDC, cases are further divided into surgical and medical partitions and then into specific DRGs.
Question 5: A patient undergoes hip replacement surgery and develops a pulmonary embolism (PE) on post-operative day 2. Which DRG consideration is MOST important?
- Whether PE is classified as a CC or MCC affecting the orthopedic DRG
- Whether the PE shifts the case from an orthopedic MDC to a respiratory MDC
- Whether the PE should be coded as the principal diagnosis instead of the hip replacement
- Whether PE documentation triggers a HAC payment adjustment for DVT/PE after orthopedic surgery (Correct answer)
Correct answer: Whether PE documentation triggers a HAC payment adjustment for DVT/PE after orthopedic surgery
Post-operative PE after hip replacement is in the CMS-designated HAC category for DVT/PE after arthroplasty. If the PE is not documented as POA=Y, the HAC payment adjustment will apply, reducing reimbursement.
DVT and PE following orthopedic procedures including hip and knee replacement are CMS-designated HACs. When these conditions develop post-operatively (POA=N), the HAC payment adjustment applies and the case is processed as if the DVT/PE were not present, reducing payment.
Question 6: Which of the following ICD-10-PCS sections is used to code procedures on peripheral veins?
- Section 2 - Placement
- Section 0 - Medical and Surgical (Correct answer)
- Section 3 - Administration
- Section 5 - Extracorporeal or Systemic Assistance
Correct answer: Section 0 - Medical and Surgical
The Medical and Surgical section (Section 0) of ICD-10-PCS covers all surgical procedures on anatomical body parts including peripheral veins.
ICD-10-PCS Section 0 (Medical and Surgical) is the largest section and covers surgical procedures on body parts throughout the body, including peripheral veins. Procedures such as vein stripping (Extraction), vein ligation (Occlusion), saphenous vein harvest (Excision), and PICC line insertion (Insertion) are all coded within Section 0.
CCDS Principal Procedure Selection and MS-DRG 2
Under ICD-10-PCS guidelines, which procedure is defined as the 'principal procedure' for DRG grouping purposes?