AS THE NURSES' STRIKE at the Washington Hospital Center wound up its 18th day yesterday, the hospital was running at slight more than half its 911-bed capacity - while the George Washington University Medical Center was jammed with patients. While that situation doesn't qualify as a total breakdown of health care in the city, the dispute - which could end tonight, when nurses are scheduled to act on settlement proposal - has had more than a routine impact on this community in terms of available service, reductions in the work hours of other employees of the hospital and the state of labor relations in hospitals generally.

The strike reflected growing nationwide demands on the part of nurses that their role in health care be altered, that they be regarded as more than just doctors' helpers. At the same time, hospital administrators have been reluctant to change what they regard as time-tested methods of caring for patients. Looking at the issues in dispute, however, it also has been a strike that should have been settled long ago.

Instead, inexperience on both sides in a labor-strike situation initially made both the hospital and the union fearful of any serious movement. That left hanging a list of "issues" that didn't seem all that complicated, and that shouldn't have taken this long to work out. For example, the nurses have been seeking permanent day shifts assigned by seniority, while the hospital administration has said that this would mean that all the inexperienced nurses would be concentrated on the evening and night shifts. Without advocating any specific change, we've wondered all along why there couldn't be some way to allow for a certain number of day shifts for senior people - perhaps one shift for every experienced nurse who volunteers for regular night duty. Similarly, one could come up with reasonable compromises on sick leave and representation questions.Now, at least, there is an opportunity to avoid a prolonged strike that could lead to serious health-care problems in the community. We hope the settlement proposal proves acceptable tonight and that the two sides can begin a cooperative effort to reassess the changing roles of nurses as well as physicians in modern health care.