BANGOR — Members of one Maine insurance plan are given a toll-free, 24-hour hot line to call when symptoms strike on weekends or at night, a number that reaches nurses in Colorado standing by to give advice.

Using a standard series of questions to search for the root of the problem, the switchboard experts determine if a caller is in bad enough shape to head for the local ER.

Some local hospitals and doctors also like the idea of having their own phone-in referral system — especially one as close by as State Street in downtown Bangor. That’s where nurse consultants answer phones at MedComm headquarters, a local medical call center with a growing list of clients including Eastern Maine Medical Center.

A collaboration between Capital Ambulance of Bangor and Affiliated Healthcare Systems, part of Eastern Maine Healthcare, the MedComm system has been taking calls since last summer. Staffers answered 6,000 calls in December, and program manager Tom Reed, a registered nurse, predicted 9,000 calls this month. Volume is doubling every 60 days, he said.

“Bangor hasn’t had anything like it,” Reed said. “The idea is that these are Maine nurses for Maine people. We’re your neighbors. We know you.”

It may sound like a sales gimmick, but the local connection can pay genuine medical dividends. When dozens of callers last August complained of a mysterious itch, answering experts were able to connect the problem at once to swimming in polluted Pushaw Lake.

A hot line in Colorado would have been hard-pressed to do that. And heaven help the Westerner trying to sort through the symptoms of a Mainer with a thick Down East accent.

Reed acknowledged that telemedicine, a growing trend, is widely perceived as cold and impersonal. Being based in Bangor helps alleviate that feeling of distance, he said. “It makes us special, and it gives great service to the community,” he said.

The medical community seems to agree. MedComm won’t reveal its list of clients — the doctors, clinics and hospitals in Bangor and around the state that pay for its services — but leaders said the list is still growing. Termed an “invisible” service, MedComm operators will answer the phone with the name of the doctor, hospital or insurance company whose patient is calling.

The fact that the operators are nurses is what makes a medical call center different from a regular answering service, the kind used by doctors at lunchtime, at night or on weekends. Phone consultants have the added advantage of a sophisticated computer program, one used at 700 call centers nationally, designed to reliably track what’s causing unseen symptoms.

Not just a Maine phenomenon, medical call centers are springing up all over the United States. “Within five years, this will be the primary source of health information,” Reed said.

If you used to leave a message for your doctor with an answering service, and now you talk to a nurse, your doctor may be making use of MedComm.

The reason is twofold. First, patients can benefit by gaining faster access to someone with medical training. At emergency rooms, time and liability limit phone diagnosis.

“I think patients find it rewarding to call and get an answer,” said Brynn Maynard, a former home health nurse who has managed calls for MedComm since its start. “The people we speak with are so grateful to know it’s not an emergency, that they can wait a day or two, rather than having someone at the other end saying, `I can’t tell you anything — if you’re worried, come in.”‘

The second reason is for overcrowded emergency rooms. The hope is that phone consultations will work as a filter, keeping less-urgent problems from clogging the system.

“Hospitals are looking at people arriving in the ER who don’t need to be there,” said Reed. “Emergency services have a very high cost. And if an ambulance is out on a call that’s inappropriate, then it’s not available for a call that is.”

The service has been useful for many calls to EMMC’s emergency department, from mothers worried about a baby’s late-night fever to tourists far from their family doctors, said Debbie Johnson, senior vice president of EMMC. MedComm nurses also help manage the symptoms of patients from Cancer Care of Maine.

“Rather than bringing someone into the crowded clinic environment, the nurse can handle the problem with the ability to be focused and responsive,” said Johnson.

MedComm makes use of two major resources: a growing staff of experienced nurses and emergency medical technicians with diverse specialties, including cancer care, home health care, emergency medicine and pediatrics, and a high-tech computer communications system for quick response and sharing of information.

A computer in the call center shows the current location of Capital’s ambulances, and chooses the one closest to the patient. With three clicks of the mouse, information about a caller can be sent to the medics on location.

If a caller has used the system before, a medical history can be called up with a click. Another click sets up a conference phone call with the ER.

Reed said about 4 percent of calls to MedComm result in ambulance transport to an emergency room. Questions are asked in an order that identifies real emergencies quickly.

For the most-urgent calls, and those in which patients can be told how to treat themselves at home, family doctors are kept informed. Among the colorful spaghetti of wires in the MedComm control center, fax machines are linked to the nurses’ computers, allowing them to click on their screens to send a call summary to a doctor’s office.

MedComm resources include computer biographies of local doctors, access to some doctors’ schedules, even a phone-in medical library with more than 1,000 recordings on health topics.

“It’s a very powerful system,” Reed said. “Once it’s set up, you can do whatever you imagine.”