Mount Sinai Hospital is considered one of the best in the country — but its emergency department is a “war zone” and a danger to the very patients it is supposed to save, current and former staffers have told The Post.

Nurses from the Upper East Side hospital recalled patients going into cardiac arrest without anyone noticing, others not being admitted to the critical care area because it was too full and staffers losing track of their charges.

They blamed staffing shortages and an obsession with profits.

“You feel helpless because there’s nothing you can do,” said Diamond Jordan, a former Mount Sinai registered nurse who quit in September.

Dr. Eric Barton, former head of emergency departments for the Mount Sinai hospital network, said he quit in July 2018 after less than a year at the helm because “I had to follow my moral compass and leave and decide this is not an organization that cares for patients.”

A report obtained by The Post shows Mount Sinai Hospital knew its emergency department had issues at least three and a half years ago, when it assembled three out-of-state medical experts to review it.

The three medical directors spent a day in the department on April 15, 2016, and were horrified by what they saw, writing in an internal report to the hospital that the conditions were “among the worst we have ever seen.’’

The report warned that staffing ratios, infection control, safety, patient boarding and conditions in the emergency department were “unacceptable in a first-class medical center” and implored Mount Sinai to rebuild the department.

“It is our opinion that the ED at Mount Sinai is inevitably going to have one or more incidents related to patient safety, quality, or infection control that will draw substantial attention from the media, public, legal system or regulators, despite the extraordinary efforts of professional staff,” the report said.

But three years later, it appears little has changed, with Barton, Jordan and five other current or former nurses claiming Mount Sinai has failed to address crucial issues.

“Every day I go to work, I feel like I am going to a war zone,” said one nurse who was too nervous to be identified.

Jordan, 26, said that on her worst days at work, she was assigned up to 18 patients. The recommended number is five or six. She said she averaged at least nine on a normal day.

A Mount Sinai spokeswoman denied that the hospital’s nurses have ever been given a patient workload as high as Jordan claims hers was, saying it was typically less than eight.

But one employee said the hospital does not count admitted patients whom emergency department nurses continue to take care of in addition to the very sick patients still being wheeled in.

Barton, 57, added that when he was hired as the Mount Sinai hospital system chair of its Departments of Emergency Medicine in July 2017 — a year after the scathing internal report — the nurse-to-patient ratio was often as high as one to 14.

“I refused to work clinically in that ED because it felt too unsafe in terms of nurse-to-patient staffing ratios and what I saw in terms of the delay of care and getting patients upstairs,” Barton said.

The spokeswoman said staffers did raise concerns about workloads but that higher-ups listened, adding 20 nursing positions this year in addition to 42 new staffers since 2016.

The hospital also hired a second nurse manager and four assistant nurse managers to support front-line providers, the rep said.

She denied the workers’ other allegations, including that patients went into cardiac arrest unnoticed or were lost track of, calling them “simply not true.”

“We’re constantly phasing in best practices and working to improve each day and each year,” the spokeswoman said.

Mount Sinai was ranked 14th in US News’ annual Best Hospitals list this year — but the index only rates sites based on their specialty departments such as oncology and does not consider emergency rooms.

And while long waits and crowded conditions are a daily reality in most New York City hospitals, Mount Sinai workers alleged their facility was the worst to work in.

Mount Sinai’s patients apparently agree that it’s loaded with problems.

The hospital is rated a “poor performer” based on its patient satisfaction scores on the state Department of Health website.

Staffers from the hospital said the poor reviews may be because patients are left on stretchers in the emergency department’s corridor, where they frequently wait for a bed for up to two days in an area one worker compared to “Times Square.”

The workers said they believe the hospital’s decision to stop using its emergency department waiting room around 2016 began a domino effect.

The move — known as “split flow” and considered a best practice — was implemented by Mount Sinai Health System after a number of incidents in which patients died in hospital waiting rooms. Among them was a man who died in 2014 after waiting eight hours to see a doctor at St. Barnabas Hospital in the Bronx.

Under the current system, each patient goes straight into the ER regardless of their condition. While that means patients are seen by a doctor within half an hour, workers said the move overloads the system, given the lack of staff and beds.

A Mount Sinai nurse told The Post: “I’ve had several situations, including a patient whose hemoglobin was 3, which means they [virtually] had no blood pumping through their veins.”

“But because it was so busy and because of delays in the lab because they had a lot of blood work, they did not discover it until several hours later, and that can be very dangerous.”

The patient survived, she said.

A nurse who quit in December said, “I’m embarrassed that this is the care we’re giving patients, especially sick ones.”

“I went in there being very optimistic and very caring and wanting to help and loving my career, to leaving there hating the business of being a nurse.’’