U.S. officials approved airlifts of IV fluids from overseas manufacturing plants on Wednesday to ease shortages caused by Hurricane Helene that have forced hospitals to begin postponing surgeries as a way to ration supplies for the most fragile patients.

The current shortage occurred when flooding coursed through western North Carolina and damaged a Baxter plant, which is now closed for cleaning. The plant makes about 60 percent of the United States’ supply of fluids used in IVs, for in-home dialysis and for people who rely on IV nutrition. They include premature babies in intensive care and patients who rely on tube feeding to survive.

The situation could become even more dire now that Hurricane Milton is hitting Florida. On Tuesday, workers at B. Braun, makers of a fourth of the nation’s IV fluids, loaded trucks at the company’s plant in Daytona Beach with the medical bags and drove them north through the night to what they hoped would be a safer location.

The Baxter plant, in Marion, N.C., and the B. Braun site in Daytona Beach manufacture about 85 percent of the nation’s supply of IV fluids. Experts on shortages have long pointed out the risk of such over-concentration of critical supplies, citing exposure to disasters like those now at hand. Even before the latest storm, supplies were tight and reflected a longstanding problem of how few companies are willing to produce crucial but low-cost and low-profit medical products.

A spokeswoman for the B. Braun site in Florida said that the company was working with federal officials and that the plant’s staff would be off work Wednesday and planned to return on Friday once the hurricane had moved on.

On Wednesday evening, the Food and Drug Administration announced that it had authorized imports of IV products from Baxter plants in Canada, Ireland, the United Kingdom and China.

The supply crunch from flooding at the Baxter plant has led the company to limit hospital customers to 40 to 60 percent of their typical supplies this week. The American Hospital Association wrote to President Biden on Monday, seeking assistance to alleviate concerns about “substantial shortages of these lifesaving and life-supporting products.”

The saline, dextrose and sterile water fluids that the Baxter plant makes have myriad uses in health care: They provide basic hydration before surgery or childbirth and can be mixed with nutrients and medications, including chemotherapies. They are widely used in life-supporting infusions for babies born prematurely. Some are crucial to treating sepsis, a life-threatening blood infection.

“When you’re coming in with sepsis, and specifically the septic shock, those one-liter bags are the most immediate form of treatments, and sometimes you’re getting two, if not three, of them in rapid succession,” said Dr. Chris DeRienzo, chief physician executive of the American Hospital Association. “There are so many special populations impacted by the shortage, what it really leads to is an impact on the whole population.”

Patients who rely on Baxter’s fluids to do at-home dialysis treatments and those who depend on IV nutrition for survival have been particularly distressed by the shortage, doctors and patients said in interviews.

Federal officials and some Baxter staff members have worked nights and weekends to try to lessen the effects of the disruption in supply.

In North Carolina, crews are working to rebuild a bridge adjacent to the Baxter site to remove and distribute truckloads of additional supplies that were not damaged in the storm.

Baxter said in a statement early Wednesday that its foreign plants were ramping up production and anticipating F.D.A. authorization to export their goods.

Given the expected deliveries, the company said it would increase its releases of supplies on Wednesday to 60 percent of normal levels from the 40 percent provided earlier this week. The company statement said it planned to resume production in phases by the end of this year. Baxter said it was not releasing an estimate on when the plant would be fully operational.

“We will spare no resource — human or financial — to restart operations and help ensure patients and providers have the products they need,” José Almeida, the chief executive at Baxter, said in a statement Wednesday.

For patients like Hannah Hale, 37, who lives in the Dallas area, help cannot come too soon. Ms. Hale found out on Monday that her specialized pharmacy could not obtain enough of the highly concentrated dextrose solution to continue giving her the IV fluid she relies on.

Ms. Hale has been sustained by I.V. fluids for eight years, she said, after undergoing extensive surgeries for Crohn’s disease, a condition in which the immune system attacks the digestive tract.

“They’re not supposed to just drop me like that,” she said, adding that calls to 14 other pharmacies did not turn up a backup source. “I don’t have any recourse.”

Texas Health, a large health system in North Texas, said that it could not comment on cases involving individual patients, but added that it had “proactively implemented IV fluid conservation measures” because of the storm-related shortages.

After The New York Times sent questions to Ms. Hale’s health care provider, the provider reached out to tell her it could help her and compound some shelf-stable nutrition she had on hand in saline, a stopgap measure. She said her last bags of her standard IV nutrition would last only until Wednesday.

Another major blow lands on an estimated 100,000 people who use the fluids, including those made by Baxter, to perform dialysis at home. Those patients need specialized liquids to help clean their blood when their kidneys are not up to the task.

The plant in North Carolina was among the largest U.S. manufacturers of fluids for home dialysis, according to William Poirier of the Renal Healthcare Association.

In the Chicago area, Northwestern Medicine doctors and nurses have been working to shore up supply of the fluids for about 90 patients doing dialysis at home. Dr. Vikram Aggarwal, medical director of the home dialysis program, said no new patients could be added right now.

“We are triaging; we are trying to risk-stratify,” he said. “Another one to two weeks with this shortage, it could be a matter of concern.”

In a letter to health care providers posted Wednesday, Xavier Becerra, the secretary of the Health and Human Services Department, said that about 400 agency workers were on the ground in the Southeast helping communities reeling from Hurricane Helene.

Mr. Becerra said the department had been working with Baxter since Hurricane Helene tore through the area to ensure the safety of company staff and to address shortfalls in supplies.

“My department commits to mitigating the impact of Hurricane Helene and doing all we can to prevent further disruption as a result of Hurricane Milton,” the letter from Mr. Becerra said.

Top officials at the Health and Human Services Department and the F.D.A. have had a lot of experience dealing with medical supply shortages in recent years. Deep gaps in adequate supplies were evident during the Covid pandemic, when nurses wore garbage bags as protective gear and automotive companies manufactured ventilators.

In 2023, a shortage of cheap chemotherapy drugs choked off supplies in the late spring and early summer, setting off a worldwide chase for back stock and new suppliers. Just over a year ago, a tornado splintered parts of the roof of a Pfizer plant in North Carolina, leading to yet another round of shortages of generic drugs.

The high-stakes shuffling of critical supplies has become a new routine as increasingly powerful and unpredictable storms upend taut medical supply chains. The current IV shortage reminded many hospital staff workers of a similar outage after Hurricane Maria in 2017, when a Baxter plant in Puerto Rico stopped making IV fluids.

And this episode aligns with the factors experts list as those that amplify the risks of disruptions to patients: The products are cheap, giving few suppliers incentive to make competing products. Given sterility requirements, the barriers to enter the field are high. And with 60 percent of supplies coming from one U.S. site, the concentration of products adds another risk factor.

Whether lawmakers and other officials will learn from the series of crises remains unclear, said Tom Cotter, executive director of Healthcare Ready, a nonprofit founded after Hurricane Katrina.

“We haven’t seen a really big uptick in investment in resiliency from the government to harden our supply chains,” Mr. Cotter said.

“Storms are reaching areas where they’ve never been before with greater severity,” he added. “There is an increased need to widen the scope of what we think is vulnerable in our medical supply chain.”