Safety lapses at the Oregon State Hospital contributed to recent patient-on-patient assaults, a federal report on the state's most secure inpatient psychiatric facility has found.

The investigation by the Centers for Medicare and Medicaid Services found that staff didn't always adequately supervise their patients and that the hospital didn't fully investigate acts of aggression, Oregon Public Broadcasting reported.

The federal agency opened the probe after receiving four complaints. Its findings were published following an unannounced, onsite survey conducted at the Salem hospital earlier this year.

A major incident detailed in the report occurred on Feb. 10, when a patient placed another patient in a chokehold until they were unconscious. The victim required "extensive" medical care for their injuries, according to the report.

Investigators also determined that the hospital failed to prevent sexual assault and sexual contact between patients.

In January, a patient was transferred out of a unit due to another patient's "hypersexual behavior," the report said. But in the new unit, the patient reported being coerced into sex.

The hospital received the federal report, known as a statement of deficiencies, on May 1. It has 10 calendar days to respond with a plan of correction.

"There will always be things we can improve, and we will continue to do so, but what persists is our dedication to the humans we are privileged to care for," interim superintendent Sara Walker said in a statement.

Once the Centers for Medicare and Medicaid Services approves the plan, it will conduct another unannounced survey to review its implementation.

The state hospital has long struggled to address staffing shortages, overcrowding and other security lapses.

Just days before receiving the statement of deficiencies, the hospital was placed on "immediate jeopardy status" by CMS after a patient died shortly after arriving at the facility. The federal agency noted that emergency response equipment was not stored in an organized way in the admissions area. They found that while this didn't contribute to the patient's death, it presented a potential future safety risk, the Oregon Health Authority said in a statement.

The jeopardy status has since been lifted, state health officials said.

Last summer, a man newly transferred to the hospital managed to escape while fully shackled and drove off in a stolen van. He was found in a pond and then taken into custody, authorities said. An ensuing federal investigation found that the hospital failed to adequately supervise and transport the patient.