"This is just another day on the job with us," said Brad Leggs, president of the California Association of Psychiatric Technicians.
The patient became agitated late Sunday morning with a female psychiatric technician's assistant and started swinging, Leggs said.
The inmate punched a male psychiatric technician in the face when he intervened, Leggs said. The technician went to the hospital's medical unit and then went home and was to see his private physician, Leggs said.
The inmate was not arrested, Leggs said. The Napa County Sheriff's Office did not respond to the incident, Capt. Tracey Stuart said.
The inmate, who had previous confrontations, was in the area of the hospital that houses patients sent there on criminal cases, Leggs said.
Jennifer Turner, spokeswoman for the California Department of Mental Health, said in a prepared statement that on Sunday "a forensic patient assaulted staff resulting in minor injuries to a few staff. Hospital police responded to the scene and worked with staff to de-escalate the situation."
A psychiatric technician was killed by a patient in October, another psychiatric technician was assaulted by a patient in December, and a hospital employee was sexually battered by a patient in March, prompting calls for increased police in secured areas at the Napa hospital.
The Department of Health Services reported 574 physically aggressive acts against Napa State Hospital staff between October 2009 and September 2010.