A nurse anesthetist whose career in the New River Valley spanned decades will serve a six-month prison sentence for taking drugs meant for patients.

Alvin Earl Parkes, 62, had pleaded guilty in June to two counts of possessing a controlled substance tied to his theft of fentanyl citrate, a synthetic opiod used to treat pain. In U.S. District Court in Roanoke on Wednesday, he was given the longest prison term recommended by federal sentencing guidelines and fined $3,000.

An emotional Parkes apologized for what he described as an ill-considered bid to ease the strain of long shifts and tough hospital conditions. He said his working life had begun as a child and he had just wanted to stay at his current job long enough to pay down the debt on his farm in Draper.

"All I know is work," Parkes said.

Trained in the U.S. Air Force in the 1970s, Parkes said in June that he came to Pulaski in 1979 and worked most of the time since then at the town's hospital.

The charges against Parkes resulted from his stealing drugs at Pulaski Community Hospital between July and September 2008. A document filed by the prosecution stated that two years earlier, Parkes similarly took fentanyl while working at Carilion New River Valley Medical Center.

Parkes said Wednesday that the amount of painkiller to be administered to each patient was determined on a moment-to-moment basis by a nurse anesthetist and a supervising anesthesiologist, a medical doctor who would oversee several patients' surgeries or other treatments simultaneously. Various monitoring equipment also tracked bodily functions that would be interpreted as signs of increased pain, Parkes said.

He said he kept the fentanyl not needed by patients, administering it to himself by an injection in his wrist, where his watchband would cover it.

He said he never felt impaired by the drug but admitted that once he found himself signing a hospital form in an unusually tiny, precise script and realized he was more affected than he had anticipated.

Assistant U.S. Attorney Charlene Day said there was no evidence that patients suffered because of not receiving sufficient drugs.

Parkes said he sometimes filled vials with distilled water to help conceal his actions but kept track of which vials were water and which were fentanyl.

Day said in June that hospital staff became aware of Parkes' activities because he began reporting a much higher rate of broken vials to explain the missing drugs.

Several witnesses, including Parkes' daughter, testified Monday that stealing and using drugs was out of character for him.

A longtime co-worker, Judy Dalton, praised his manner with patients, saying he had been part of her own medical team when she underwent two procedures.

"Patients still come through and ask for him," Dalton said.

Judge Samuel Wilson said he recognized that Parkes had led "an otherwise exemplary life" but said the problem of drug diversion within the health care industry is a serious one. He opted for the upper end of sentencing guidelines that ranged from no incarceration to six months behind bars. Wilson said that Parkes will be supervised by the federal probation office for a year after his release.

Parkes has given up his license to practice medicine.