"You can't be stoned while on the job," Anne Skånberg of the human resources department of Sahlgrenska Hospital told The Local.
Staff at the hospital first noticed signs that the nurse, who had worked at the hospital for nearly a decade, may have been drugged after his questionable behavior in response to a patient's worsening condition.
The patient had previously been taken from intensive care to the regular ward, but when the patient's symptoms deteriorated, the nurse, who was responsible for monitoring the patient, was nowhere to be seen.
Colleagues later described him as being "indifferent, absent, and detached" according to a report about the incident filed with the National Board of Health and Welfare (Socialstyrelsen).
Following the incident, which took place in December 2011, the nurse was forced to take a drug test, which revealed he had been under the influence of cannabis.
"He had smoked hashish, but we're not sure if he did it at the hospital or before coming to work," said Skånberg.
According to Skånberg, the nurse has since been relieved of his position while the hospital awaits word of any additional consequences that might stem from a health board investigation of the incident in accordance with Lex Maria, the informal name for regulations governing the reporting of injuries or incidents in the Swedish health care system.
While she admitted that the hospital occasionally has problems with staff who steal medicines, Skånberg said it was "extremely rare" to have a nurse high while on duty.