Blair Eig, a Silver Spring pediatrician and his three partners offer the standard array of laboratory tests in their office: strep throat cultures, urinalyses and similar diagnostic procedures that their 2,000 patients count on. An office lab, according to Eig, is good for his practice and good for his patients, who can receive test results within hours, rather than waiting the day or two it takes to get results from a commercial lab. "I can make a faster diagnosis, treat the patient more quickly and do it at less expense," Eig said.

But sweeping changes in the way the federal government regulates doctors' office labs -- rules designed to ensure the quality of all medical tests -- will change the manner in which Eig and hundreds of thousands of other doctors run their office labs -- if they run them at all.

Currently, the federal government's Health Care Financing Administration (HCFA), oversees about 12,000 labs, most of them run by hospitals that receive reimbursement from Medicare and Medicaid, the federal programs that care for the elderly, the disabled and the poor. The Clinical Laboratory Improvement Amendments of 1988, which will take effect next year, require that the federal government oversee the operation of tests performed in 300,000 laboratories -- a third of them located in doctors' offices. The law, sponsored by Sen. Barbara Mikulski (D-Md.), was prompted by a prize-winning series of reports in the Wall Street Journal that exposed widespread deficiencies in the quality of labs that analyze Pap smears, which check for cervical cancer, a disease that kills 6,000 women annually.

Recent regulations developed by HCFA have created a furor among doctors, whose organizations -- including the American Medical Association and the American Academy of Pediatrics -- have waged vigorous lobbying campaigns against them. These groups are attempting to persuade federal health officials to modify the proposed regulations.

In the past two months, medical journals and newspapers have been full of stories and editorials warning of the dangers of the proposed regulations and urging members to write letters of protest to Congress and HCFA.

". . . We must convince HCFA that implementation of regulations in the current form would be a disaster of national proportion affecting many patients from all geographic regions," said Joseph T. Painter, chairman of the AMA Board of Trustees in an open letter to doctors published two weeks ago in American Medical News. "The most effective arguments are those made by large numbers of individual physicians," he added.

And large numbers of physicians have heeded the call. Thomas Morford, a HCFA official who is overseeing the new regulations, says his agency has been inundated with more than 25,000 letters and telegrams since May, when the regulations were first advertised in the Federal Register.

Opponents say that the law, which will require licensure, periodic inspection and proficiency testing of all labs, is burdensome and unnecessary and will limit consumers' access to lab tests and raise their cost. Some physicians' groups have estimated that it will cost $2 billion to implement the regulations as written.

Critics say they aren't against tougher laboratory standards. "We're not opposed to improving accuracy, proficiency or efficiency of laboratories," said AMA executive vice president James S. Todd. "Our only concern is the method by which it is done."

The debate over lab testing "mirrors a lot of other problems in medicine," said Sidney Wolfe, the physician who heads the Washington-based Health Research Group, a nonprofit advocacy group founded by Ralph Nader. "The whole health care system is a $661 billion pot of gold, and everyone wants to cash in on it."

Lab tests performed in doctors' offices are lucrative. About $5 billion is spent annually on the more than 500 million tests performed in physician office labs, according to a 1988 report by the Maryland Department of Health and Mental Hygiene.

Although Wolfe said that some physicians' offices have done a good job conducting and interpreting lab tests, tougher regulations will probably improve the quality of care, he added.

Many physicians, who have run their office laboratories largely or entirely free of regulation, disagree. They say that the new rules would harm their practices by requiring them not only to become licensed by HCFA but would stipulate which tests they can perform. "It's another example of the intrusion of the federal government into the practice of medicine," said Todd.

Under HCFA's proposal, labs would be divided into three categories, depending on the sophistication of tests they offer and the degree of risk of the conditions they detect. Those performing 17 of the most elementary tests ranging from pregnancy tests to dip-stick urine tests that detect sugar, which can indicate diabetes, would be exempt from regulation because they are "simple and low-risk," according to HCFA administrator Gail Wilensky.

Labs offering more-complicated tests, such as cholesterol screening, would be required to have a physician, chemist or a biologist with a PhD run their labs. In the case of a group practice, one doctor could be designated as the lab chief. But labs that perform more complex blood chemistry tests would have to hire either a board-certified pathologist or a PhD trained in laboratory medicine.

Nurses and secretaries who now perform many lab tests would no longer be permitted to do so under the new regulations. Doctors would be required to hire trained, licensed technicians to run many tests. In the case of the most complicated tests, state-licensed medical technologists with college degrees would be required.

Most physicians say they could not afford to employ such highly trained personnel to supervise their labs and that few medical doctors or PhDs would be willing to take such jobs even if they could.

While the problem of so-called "Pap mills" was the impetus for the new law, other reports have shown that the quality of office labs varies considerably. Several studies published in the Journal of the American Medical Association found wide variations in blood cholesterol testing, depending on the method used to analyze specimens and how well-trained the technicians were. According to John M. DeBoy, chief of Maryland's division of laboratory licensure, of 72 cytology labs in a pilot test last year, 26 percent failed. In a similar survey this year, 14 percent of 73 cytology labs participating failed a proficiency test.

Mikulski says that congressional action in the form of the new law was also spurred in part by foot-dragging on the part of HCFA. "Five years ago, we passed a law telling HCFA to report on minimum standards for physician office labs," she said. "That report was never issued."

In 1987, Congress passed a law requiring the agency to regulate office laboratories that perform more than 5,000 tests annually. "No standards were ever developed," said Mikulski.

Much of the delay in implementing tougher lab regulations, HCFA officials say, reflects a lack of consensus about which tests can safely be offered in doctors' offices, how they should be performed and by whom.

"No one in the agency ever dragged their feet. We did the best we could," said Morford, director of HCFA's Health Standards and Quality Bureau. "It's been a monumental scientific task."

Under pressure from Congress to implement the law, HCFA required its own experts as well as those from the Food and Drug Administration and the Centers for Disease Control "to come up with reasonable proposed rules," Morford said.

Although opponents of the regulations, among them the AMA's Todd, claim that they will "markedly increase the cost of laboratory services to patients," the experience in Maryland, one of a handful of states that now regulates physician office labs, indicates that an increased cost is not inevitable.

According to DeBoy, well-run physicians' office labs spend about 13 to 14 percent of their gross income on quality control. For these labs, the new regulations probably wouldn't cost more, because many are already doing what the new regulations would require.

Finding a way to resolve doctors' complaints about the new law and implement it as Congress requires may be a difficult task, but it is vital to doctors like Eig and to their patients. "We're not asking for no regulation," he said, "we're asking for appropriate regulations."