The federal agency that keeps its fingers on the nation's economic pulse says it may have to reduce the number of times it checks its patient unless Congress moves quickly to give it more money.

The Bureau of Labor Statistics, which issues the Consumer Price Index, employment and unemployment statistics and inflation figures every month, told its 1,900 employes last week that they may face furloughs starting next month, if the agency doesn't get an additional $5.6 million immediately.

The extra funds are included in H.R. 5922, a $4.9 billion supplemental appropriations bill that Congress is expected to take up soon. If the extra funds are not approved, the bureau will have to make more reductions in the amount of data it collects and could be forced to delay issuing many of its reports, including the CPI, said William Barron, the bureau's administrator.

Such budget-cutting moves could affect millions of Americans whose incomes are tied to the bureau's inflation figures. The numbers, for example, help determine the salaries of people whose wage contracts include cost-of-living adjustments. The CPI also automatically determines the size of some federal benefits.

Like a number of other federal agencies, the bureau got into financial trouble because of a two-phased budget crunch. The Labor Department agency has been operating in fiscal 1982 under a continuing budget resolution because its appropriations bill still hasn't passed Congress. Last spring, President Reagan ordered the agencies to cut their 1982 budgets by 12 percent across the board. When Congress passed a continuing resolution in December to keep the government operating, it pegged agency spending levels to 4 percent below whichever appropriations figure was lower, the House's or the Senate's. The result was a 16 percent budget cut for the bureau.

To comply with the 12 percent cut, which dropped the bureau's budget from the $123 million it wanted for fiscal 1982 to $108.3 million, the bureau ended 19 programs, stopped all travel and did not replace more than 100 employes who quit or retired.

Among the programs that got cut were employer compensation studies, wage surveys by area and industry, collective bargaining agreement surveys, and wage chronologies. Those cuts prompted an AFL-CIO official to charge at a recent congressional hearing that the decision was "anti-labor," because the programs often provide valuable information to unions for use in collective bargaining talks.

But Barron countered that the bureau ended the programs because it thought they served the fewest people. "It had nothing to do with politics," he said.

Barron contends the bureau has cut every expense it can without harming its main statistical projects, the CPI and employment-unemployment figures. Faced with the extra 4 percent cuts, Barron said, the agency now must begin furloughs.

From the beginning, the bureau has avoided reductions in force (RIFs) and furloughs because "such moves would make it difficult to continue producing an accurate CPI," Barron said.

All but 461 of the bureau's 1,900 employes are economists, statisticians, budget analysts or computer technicians, said Barron, and thus it "has very few people it can RIF." Most of the bureau's staff works on some part of the CPI, employment or inflation figures, he said.

Echoing complaints made by other agency managers, Barron noted that if the bureau had to RIF employes, it would have to give more senior employes "bumping rights," which would cause the bureau to "end up with people doing jobs that they knew nothing about."

"In an agency which has to meet quarterly or annual deadlines, that might work. But we have to put out the CPI and other data every month."

The CPI, for instance, is based upon reports from 350 part-time data collectors in 85 cities who sample prices at retail outlets and send the information to the bureau for analysis, Barron said.

Getting the bureau more money has been a difficult process, bureau officials and staff members of the House Appropriations Committee said.

Under its rules, the House cannot vote on any new spending bills once government spending reaches the $695.4 billion budget ceiling that Congress approved last spring. Government spending currently is estimated to be $738 billion by the Congressional Budget Office--well over the budget ceiling.

That forced the Appropriations Committee to ask the House Rules Committee to waive the ceiling for the supplemental appropriations bill. The Rules Committee agreed to the waiver after it decided that funds in the bill for six items--but not the bureau--were not emergencies and would not be protected if anyone challenged them.

According to his staff, Rep. Jamie L. Whitten (D-Miss.), chairman of the Appropriations Committee, plans to talk with the House leadership this week about the emergency funding bill. "He plans to count heads this week," an aide said. Meanwhile, at the bureau, Barron and his fellow employes are hoping Whitten's "congressional statistics" will be in their favor.