Frontline medical workers at one of New York’s best resourced and most prestigious public hospitals have warned the facility is in critical need of nursing staff, protective equipment, ventilators and medicines to cope with the rising number of coronavirus cases in New York City.

Staff at Bellevue hospital in Manhattan, the oldest public hospital in the US, have been warned not to speak to the media, except with explicit approval. But medical workers told the Guardian on condition of anonymity that they were concerned about what would happen as cases continue to rise.

“We are heading towards a situation where we will run out of ventilators,” said one doctor at the hospital working on the Covid-19 response. “I hope that this surge isn’t as bad as we predict.”

Bellevue hospital has been the battleground for epidemics for centuries – yellow fever in the 1700s, cholera in the 1800s and Aids in the 1980s. It even successfully treated New York City’s lone case of the Ebola virus in 2014. But little could have prepared Bellevue for Covid-19.

Arguably one of the best-positioned public hospitals in the nation to deal with the pandemic, Bellevue normally has more than 800 beds and support from New York University (NYU). For the past few weeks, it has made sweeping changes to staff numerous new Covid-19 wards at the hospital, as well as the existing emergency room and ICUs.

Physicians and nurses normally working in clinical outpatient settings are now working in screening tents, and the hospital is deploying surgeons and other specialists to work across the hospital wards. NYC Health + Hospital System, which oversees Bellevue and 10 other public hospitals in the city, announced that the hospital will receive 52 more ICU beds, and more frontline staff in coming days.

“We’re getting better coordinated by the day,” said Dave Chokshi, a primary care physician at Bellevue and vice-president at New York Health + Hospitals. “Within our system, Bellevue is one of the most advanced hospitals with respect to the range of services it offers. It does end up being a place where the sickest patients go.”

The hospital has also pared back other inpatient services to make room for coronavirus patients – regular appointments and clinics are canceled. And telemedicine has surged from 50 patients a day to 3,000 a day at NYU.

Health workers said they still see a breaking point ahead. “So many people working in direct care are getting sick,” said a hospital physician. “And we’re still rationing masks.”

Like many hospitals in the country, several staffers outside of the emergency room at Bellevue said they currently have only the lowest level of personal protective equipment (PPE) available – surgical masks – and are not allowed to bring the more protective N95 masks to work, even if they have them at home.

Emergency medicine residents at Bellevue hospital asked for money on GoFundMe to obtain N95 respirator masks. They raised more than $120,000, and obtained 10,000 masks for the emergency department and intensive care unit. Health workers said they’ve seen more supplies delivered recently, but still worry that will not sustain them through the peak of Covid-19 infections, And some have reportedly quit or taken leave as a result.

A worker from the office of chief medical examiner stands in front of a refrigeration truck outside Bellevue hospital in New York. Photograph: Angus Mordant/Bloomberg via Getty Images

Meanwhile, droves of potential patients wait in tents outside Bellevue, where they are triaged for tests, including sick service workers from nearby restaurants needing a letter from a doctor not to work. Most, however, will not receive a Covid-19 test – a nationwide lack of swabs and reagent, a liquid essential to the test, has limited testing at Bellevue and its sister hospitals to only the critically ill patients in ICUs and frontline health workers.

City officials project every hospital bed in New York City – 20,000 in normal circumstances – will need to be transformed into critical care beds to care for Covid-19 patients on ventilators.

Inside the wards, physicians in the system said Bellevue has a critical need for more ventilators as the weeks go on, and is on track for running out by the end of the week. Last week this urgency led the hospital, like others, to form an ethics committee to decide which patients receive a ventilator or other treatments, should they need to ration equipment. “It was quite scary,” one physician said.

New York is expected to need 15,000 to 18,000 ventilators at the peak if the rate of people getting sick does not decrease, but it currently has fewer than 10,000. New York’s mayor, Bill De Blasio, has urged private practices and even veterinarians to loan ventilators to the city, measures he said need to be in place by Sunday.

And federal health officials on Tuesday advised hospitals to retrofit anesthesia machines as ventilators, and to double up patients with similar oxygen needs on to a single ventilator as a last resort.

“The availability of precious medical resources will be limited in some places because of the numbers of patients and their severity of illness,” said Adm Brett P Giroir, the assistant secretary for health, about current projections.

Bellevue always hemorrhages money but it’s the stopgap – it’s the hospital that takes patients others won’t admit David Oshinsky

Even in these dire circumstances, Bellevue staff told the Guardian that the hospital is in better position than others in the city, and has not yet reached full capacity. One physician working in the wards said there was no need for more physicians or beds at the moment, but expected that there would be in coming days.

Bellevue is also known for taking care of a diverse range of patients, including significant populations of low-income New Yorkers and immigrant communities. It’s entire 19th floor is a prison ward for men at Rikers Island, where officials have warned that coronavirus cases are rising dramatically.

Like other hospitals in the public system, it is accepting patients from other hospitals like Elmhurst hospital in Queens, and Lincoln medical center, in the Bronx, as they run out of beds and resources.

“Bellevue always hemorrhages money but it’s the stopgap – it’s the hospital that takes patients others won’t admit,” said David Oshinsky, a professor of medicine at NYU Langone, who chronicled the hospital’s history in his book Bellevue: Three Centuries of Medicine and Mayhem at America’s Most Storied Hospital.

Across the city, 250 ambulances and 500 nurses have been brought to New York. The USNS Comfort, a navy hospital ship with capacity for 1,000 beds has docked at New York Harbor to treat non-Covid-19 patients. The Billie Jean King tennis center is being transformed into a 350-bed overflow for Elmhurst hospital, another public hospital in the Health + Hospital System in Queens, home to roughly one-third of the cases in the five boroughs of the city.

The death toll across the city, and at the hospital, however, is rising. Outside Bellevue, the city’s chief medical examiner has set up massive tents and refrigerator trucks to handle a surge in deaths. And inmates at Rikers Island are now being offered $6 an hour to dig temporary mass graves on Hart Island, at a city-run cemetery.

As Bellevue’s physicians and staff prepare for the peak of Covid-19 patients, they are hoping that the hospital will be able to draw on its past and curb the city’s death and disease.

“Our house staff is superbly trained – they’re also used to this in ways other hospitals may not be,” Oshinsky said. “There’s such a history of epidemics when all hands on deck were needed at Bellevue.”