Transition To Residency · Year 4 · from Transition To Residency
Case 1: Swiss Cheese Model and Medication Error
Clinical Image
Source: Wikipedia - Swiss cheese model - CC BY-SA 4.0
Case Presentation
A 65-year-old male with chronic kidney disease (GFR 28 mL/min) is admitted for cellulitis. The admitting intern orders vancomycin at a standard dose of 1g IV every 12 hours without renal adjustment. The hospital's CPOE system generates a renal dosing alert, but the intern clicks through it as she has been conditioned to override "frequent" alerts. The pharmacy is short-staffed overnight and the order is verified without clinical review. The nurse administers the medication as ordered. After 5 days, the patient develops acute kidney injury and ototoxicity. Root cause analysis using the Swiss cheese model reveals multiple defense layer failures: (1) physician layer - ordering error with alert fatigue contributing to override; (2) pharmacy layer - inadequate verification due to staffing; (3) nursing layer - no independent dose calculation for high-risk medication; (4) system layer - excessive alerts causing desensitization. The error passed through aligned holes in all defense layers. Recommendations include: implementing mandatory hard stops for vancomycin in renal impairment, pharmacy staffing review, nurse education on renal dosing, and reducing low-value alerts to combat alert fatigue.
Key Learning Points
- The Swiss cheese model illustrates how errors reach patients when holes in multiple defense layers align simultaneously
- Human factors including alert fatigue, cognitive overload, and staffing constraints create vulnerabilities in safety systems
- Effective prevention requires multiple safeguards at different system levels so that when one fails, others prevent harm