After patients complained of excruciating pain on the operating table, a hospital suspected there was a problem with the anesthesia and sent two intravenous drug bags to the laboratory for analysis.
The mixtures, prepared by Dr. Frank Ruhl Peterson, were found to contain only trace amounts of painkillers.
The anesthesiologist, it turned out, was shortchanging the patients and diluting the medication to feed his own drug habit.
On Tuesday, Peterson, 45, was sentenced to 10 to 23 months in prison.
Peterson was assigned to anesthetize more than 200 patients while working at hospital from June to August.