The next time you’re due for a medical exam you may get a call from someone like Ana: a friendly voice that can help you prepare for your appointment and answer any pressing questions you might have.

With her calm, warm demeanor, Ana has been trained to put patients at ease — like many nurses across the U.S. But unlike them, she is also available to chat 24-7, in multiple languages, from Hindi to Haitian Creole.

That’s because Ana isn’t human, but an artificial intelligence program created by Hippocratic AI, one of a number of new companies offering ways to automate time-consuming tasks usually performed by nurses and medical assistants.

It’s the most visible sign of AI’s inroads into health care, where hundreds of hospitals are using increasingly sophisticated computer programs to monitor patients’ vital signs, flag emergency situations and trigger step-bystep action plans for care — jobs that were all previously handled by nurses and other health professionals.

Hospitals say AI is helping their nurses work more efficiently while addressing burnout and understaffing. But nursing unions argue that this poorly understood technology is overriding nurses’ expertise and degrading the quality of care patients receive.

“Hospitals have been waiting for the moment when they have something that appears to have enough legitimacy to replace nurses,” said Michelle Mahon of National Nurses United. “The entire ecosystem is designed to automate, de-skill and ultimately replace caregivers.”

Mahon’s group, the largest nursing union in the U.S., has helped organize more than 20 demonstrations at hospitals across the country, pushing for the right to have say in how AI can be used — and protection from discipline if nurses decide to disregard automated advice. The group raised new alarms in January when Robert F. Kennedy Jr., the incoming health secretary, suggested AI nurses “as good as any doctor” could help deliver care in rural areas. On Friday, Dr. Mehmet Oz, who’s been nominated to oversee Medicare and Medicaid, said he believes AI can “liberate doctors and nurses from all the paperwork.”

Hippocratic AI initially promoted a rate of $9 an hour for its AI assistants, compared with about $40 an hour for a registered nurse. It has since dropped that language, instead touting its services and seeking to assure customers that they have been carefully tested. The company did not grant requests for an interview.

AI in the hospital can generate false alarms and dangerous advice Hospitals have been experimenting for years with technology designed to improve care and streamline costs, including sensors, microphones and motion-sensing cameras. Now that data is being linked with electronic medical records and analyzed in an effort to predict medical problems and direct nurses’ care — sometimes before they’ve evaluated the patient themselves.

Adam Hart was working in the emergency room at Dignity Health in Henderson, Nevada, when the hospital’s computer system flagged a newly arrived patient for sepsis, a life-threatening reaction to infection. Under the hospital’s protocol, he was supposed to immediately administer a large dose of IV fluids.

But after further examination, Hart determined that he was treating a dialysis patient, or someone with kidney failure. Such patients have to be carefully managed to avoid overloading their kidneys with fluid.

Hart raised his concern with the supervising nurse but was told to just follow the standard protocol. Only after a nearby physician intervened did the patient instead begin to receive a slow infusion of IV fluids.

“You need to keep your thinking cap on— that’s why you’re being paid as a nurse,” Hart said. “Turning over our thought processes to these devices is reckless and dangerous.”

Hart and other nurses say they understand the goal of AI: to make it easier for nurses to monitor multiple patients and quickly respond to problems. But the reality is often a barrage of false alarms, sometimes erroneously flagging basic bodily functions — such as a patient having a bowel movement — as an emergency.

“You’re trying to focus on your work but then you’re getting all these distracting alerts that may or may not mean something,” said Melissa Beebe, a cancer nurse at UC Davis Medical Center in Sacramento. “It’s hard to even tell when it’s accurate and when it’s not because there are so many false alarms.”