What Happened

Blake Daniel Zenner, a registered nurse at a hospital in St. Cloud, Minnesota, withdrew Dilaudid from patients' IV bags via hospital lockboxes and reinjected the bags with saline to mask the theft.

Between November 2010 and March 2011, Zenner accessed hospital lockboxes and used syringes to withdraw hydromorphone from patients' IV bags, at times reinjecting the bags with saline before they were returned for patient use. As a result of his actions, approximately 25 hospital patients developed bacterial infections traced to the tampered bags.

Zenner pleaded guilty to obtaining a controlled substance by fraud. On March 20, 2013, U.S. District Court Judge Patrick J. Schiltz sentenced him to 24 months in federal prison and ordered him to pay $340,000 in restitution.

What Went Wrong

Tampered IV bags were returned to circulation and administered to roughly 25 patients before the source was identified. Key failures included:

  • Lockbox access did not prevent a single nurse from removing medication from prepared IV bags undetected.
  • Tampered bags were not identified before administration, allowing bacterial contamination to reach dozens of patients.
  • The infection cluster was investigated as a clinical event before being traced back to a diversion source.

How It Could Have Been Prevented

  • Use tamper-evident seals on prepared IV bags containing controlled substances and verify seal integrity immediately before administration.
  • Restrict lockbox access to the specific bags assigned to a nurse's own patients, with access logged and reviewed.
  • Investigate unexplained hospital-acquired infection clusters for a possible diversion source alongside standard infection-control review.
  • Reconcile IV bag weight or volume against expected dosing before and after lockbox access.

Related Guidance

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