The Maine Emergency Medical Services board sets the protocols regarding when LifeFlight goes to a call. The air service is called when:

• There’s a need for speed. The helicopter has a cruising speed of 168 mph and can go from Lewiston to Boston in 40 minutes.

• Ground transport would be impossible or too risky. LifeFlight can land in even the most remote areas.

• A patient needs specialized care. Between the crew’s extensive emergency medical training and the medication and medical supplies LifeFlight carries – including blood, paralytics and intubation equipment – the helicopter is essentially a flying intensive-care unit.

“Half of what we do is having to be prepared for the worst,” said Lori Metayer, who serves as program coordinator in Lewiston and as a flight nurse and medic.

For hospital calls, the patient’s doctor decides whether to bring in LifeFlight.

On scene, first responders do.

If there’s any question about whether a patient should be taken by LifeFlight, or where the person should go once in the air, doctors at Central Maine Medical Center, Eastern Maine Medical Center in Bangor and Maine Medical Center in Portland can be consulted.

LifeFlight can also decide whether it should take someone. Crew members can turn around mid-air if it sounds like the patient doesn’t need them. They could also reach the scene, assess the situation and decide the person should go by ground. And if any of the three crew members feel like the flight itself would be dangerous – because of bad weather or other conditions – they can cancel a flight.

On average, only about 3 to 4 percent of LifeFlight patients are discharged from the hospital within 24 hours, one measure, national experts say, of how seriously ill or injured an individual is when LifeFlight is called in.