Health care workers at Chosun University Hospital hold signs and chant slogans at the hospital's lobby on Thursday, signaling the start of their strike. (Yonhap)

Unionized hospital workers pulled out from their planned strike Thursday after reaching an agreement on pay raises and better working conditions with hospitals, withdrawing from a decision that could have caused potential chaos at understaffed hospitals already suffering from junior doctors' collective walkouts in February.

The Korean Health and Medical Workers' Union -- which has some 30,000 nurses, caregivers and other medical workers as members -- said Thursday that health care workers at 59 out of 62 hospitals clinched last-minute wage deals and other demands. They include the Korea University Medicine Centers in Anam, Guro and Ansan, and Hanyang University Medical Centers in Seoul and Guri.

Honam Regional Rehabilitation Hospital will continue negotiating and stage sit-in protests at the hospital starting Friday, while Nowon Eulji Medical Center has extended its mediation period until September 11, according to the union.

Having yet to come to an agreement, some 800 medical workers at Chosun University Hospital in Gwangju proceeded with the move, according to the union. The hospital estimated that around 300 workers were participating in the strike. The union added that around 400 people working in essential fields, such as operating rooms, intensive care units and delivery rooms, were staying to minimize disruptions in medical services.

The surprising move to call off its planned action comes a day after the National Assembly passed the Nursing Act, which aims to provide a legal framework for physician assistant nurses to assist doctors in performing medical procedures and offer enhanced legal protection to nurses. Observers believe it played a pivotal role in changing course as nurses make up most of the union.

Nurses called on clarifying each profession's specific roles and responsibilities, as the scope of conducting medical procedures done by doctors and nurses was often blurry here.

The nationwide union of nurses and medical workers urged a wage increase, the elimination of illegal medical practices and the implementation of a four-day workweek pilot program. They also demanded the protection of health care workers from being held solely responsible for the medical vacuum in patient care caused by the absence of physicians.

"It was challenging to find the middle ground between medical institutions and health care workers due to hospital management conditions that have worsened following the junior doctors' strike. Failing to reach an agreement could have led to a bigger medical crisis," the union said in a statement.

Concerns over a potentially larger medical crisis loomed after 91 percent of the union members voted to strike last Saturday if the arbitration by the labor relations committee failed to reach terms, despite repeated pleas from the government to shelve their plans.

The union last walked out July 13-14 last year when nurses, medical technicians and care workers at 140 hospitals protested for better working conditions.

Meanwhile, the Korea Severe Disease Association welcomed the decision, noting that medical professionals should refrain from staging strikes that could put patients' lives at risk.