Medical Helicopter Care and Transport: State of the Science

July 2010
Summary illustration - Medical Helicopter Care and Transport: State of the Science

Summary

Medical helicopter transport has become much more. Thanks to research and rigorous training, the Mayo One staff delivers state-of-the-art care as soon as they reach patients.

Kathy Berns

Kathy Berns

A tour bus veers out of control across an Interstate highway in southern Minnesota, rolling on its side, injuring and trapping passengers. Moments later a school bus collides with another vehicle, sliding off a state highway.

It was a busy evening for the crews of Mayo One. The pilot, flight nurse and flight paramedic land in fields or roadways to get as close as they safely can to patients. It's emergency transportation, yes, but Mayo One is also a modern medical care delivery system. This means treatment begins the moment the team in the blue flight suits reaches patients.

"The situations you encounter in emergency services are exciting, but also gratifying," says Kathy Berns, a certified Clinical Nurse Specialist and flight nurse with Mayo One. "You make a difference for people during the worst day of their life."

Mayo flight crews also make a difference because they are constantly improving, through training, and also through research in this specialty environment.

Shock in the Sky

Christopher Russi, D.O.

Christopher Russi, D.O.

Mayo Clinic conducts research to ensure its patients are getting the best care anywhere and that includes at 2,500 feet in the air. Even in the extreme conditions Mayo One encounters, flight crews are doing scientific research for the same reason.

Take shock, for instance.

Medical shock is a life-threatening emergency in itself, and one of the most common causes of death for the critically ill because it may lead to a lack of oxygen in arterial blood or multi-system organ failure. Determining what type of shock a patient is experiencing can save their life. Mayo One crews often see patients before the classic signs occur. "The ability to recognize shock can be elusive," says Christopher Russi, D.O., emergency medicine specialist and chair of Mayo's emergency medical services (EMS) research committee.

The National Institutes of Health is funding a Mayo study on flight crews' ability to assess medical shock and its impact on patient care. As with many of the EMS and Mayo One research projects, this one studies patient care delivered by the crew. Other projects involve review of the medical record or hospital outcomes. Few of these research projects involve traditional clinical studies because it is challenging to obtain patient consent at the time of transport, says Dr. Russi.

Through part of his role, Dr. Russi develops educational programs to help improve the diagnosis of shock by flight teams and to evaluate the program's effectiveness. Dr. Russi describes the four types of shock as falling along a spectrum:

  • Hypovolemic shock is most often due to blood loss or dehydration.
  • Cardiogenic shock is caused by a heart attack or congestive heart failure.
  • Obstructive shock occurs when the ability of the heart to pump blood is restricted. This could be due to a heart attack or severely collapsed lung.
  • Distributive shock happens when there's been a spinal cord injury or from overwhelming infection (sepsis). The blood vessels lose their tone and circulation stops.

A related project of Dr. Russi's investigates the effectiveness of a non-invasive tissue oxygen monitor to detect the first stages of hypovolemic shock. The tissue oxygen monitor, called an InSpectra StO2 Tissue Oxygenation Monitor developed by Hutchinson Technology Inc. uses a sensor that fits in a patient's hand. The sensor emits four beams of near infrared light to test the underlying muscle tissue for oxygen saturation. The InSpectra monitor detects low oxygen levels before the classic signs and symptoms of shock manifest. Dr. Russi is looking at the feasibility of using the monitor in a helicopter environment and hopes to develop treatments correlating to the StO2 values in future studies.

Dr. Russi finds research in the EMS field particularly satisfying. "There are a lot of questions left to ask and dogma to refute. I like to design a way to find answers. If you can gain better outcomes for patients, that's number one."

Improving Patient Outcomes

Two other Mayo One studies have already improved emergency care for patients. They involve changing how helicopters are dispatched to a scene and what equipment they carry. Helicopters were previously dispatched only after an ambulance crew or law enforcement had arrived and deemed it necessary. Now at Mayo, that decision is in the hands of the 911 dispatchers. That practice is called Autolaunch.

"When a call comes into a dispatch center, the dispatcher sends the helicopter at the same time as the ambulance," says Berns. "This can save 10 to 15 minutes, which is vital for a victim in an emergency." The dispatcher considers key medical criteria, the situation at the scene of injury and the likelihood of serious injuries. Examples include vehicle rollovers, head-on collisions, pedestrian-vehicle accidents, and other major sources of trauma.

Shortening the time it takes to get a helicopter launched means quicker medical response at the patient's side and earlier arrival at the trauma center. Berns says their research demonstrates that Autolaunch saves lives and improves patient outcomes. The Mayo One findings were published in Air Medical Journal in 2002 and were later presented at the Aeromedical World Congress in Norway and Switzerland. The study has also been shared at several venues across the United States.

Few emergency helicopter services carry blood for en route transfusion, and even fewer carry both blood and plasma. Administering blood during transport can be critical to avoiding complications from shock. Mayo One conducted research on the feasibility of having blood on board and those findings were published as early as 1998 in the Air Medical Journal and presented at several conferences in Austria and Germany in addition to the U.S. All Mayo One helicopters are equipped to carry blood, and the Mayo One aircraft in Rochester also carries plasma. Research on the benefits of carrying plasma is currently being conducted. The helicopters are also equipped with special warming compartments for saline solution and other fluids.

Seeing at Night

Jeffrey Stearns

Jeffrey Stearns

Other Mayo One Research

  • Evaluating effectiveness of Airtraq optical device, which uses prisms and mirrors to help proper placement of breathing tubes.
  • Study on ventilator masks significantly decreased necessary intubation rates, improved patient comfort, reduced complications and shortened hospital stays.
  • Retrospective records study helped improve ventilator settings by crew members.
  • Mayo One crews obtained patient blood samples to help better identify those who may develop blood clots.
  • A Mayo One study discovered one of five trauma patients is overtriaged due to alcohol intoxication. Despite having one of lowest rates, crews are continuing to address preventable forms of overtriage.

Flight nurse Jeffrey Stearns is based at Eau Claire, Wis., but his research efforts are impacting care and safety throughout Mayo One's five-state flight area.

"Let's say it's a new moon night and you're descending into a landing zone," Stearns says. "What you see are flashes of red and blue, but even with our landing lights on, around that scene it's a black hole. Are there trees? Where are the tree lines? Are there telephone poles or power poles with lines? All those are potential obstacles."

In 2006, Mayo became only the third civilian air medical service in the country to have all crew members use night vision goggles on all flights at night.

By wearing night vision goggles, crews can see objects nearly as though it were daylight, says Stearns. Stearns and Mayo Clinic's transport division have also been involved in discussions with the Federal Aviation Administration and the National Transportation Safety Board on how the entire air medical transport industry can provide the highest amount of safety.

"From our viewpoint, it's hard to imagine working without night vision goggles. They're a critical piece of equipment for safety," Stearns says. He's awaiting word on a research grant designed to collect data on the safety benefits of night vision goggles. Stearns plans to work with Fort McCoy in Sparta, Wis., to use their multi-purpose flight operations area to create different landing zone situations.

"We'll film them with one camera using a night vision goggle and one camera without," Stearns says. "We'll test our crews on the landing zones and, using simple geometry, calculate the time to obstacle avoidance on a standard rate of descent. We'll be able to quantify the difference between aided and unaided night vision for the emergency medical transport environment."

Jeff Stearns was recently named International Medical Crew Member of the Year by the Association of Air Medical Services for his work to promote the improvement of patient care in the emergency medical transport community.

Coordinating EMS Research

Dr. Russi oversees all these studies and assists anyone who wants to conduct EMS research projects. Research coordinator, Luke Myers, a registered paramedic, is also a vital committee member. He assists with data entry and reports outcomes. Myers says the group logged 17 publications last year involving research conducted through Mayo Clinic Medical Transport, which includes the four Mayo One helicopters, Mayo MedAir jet ambulance and Gold Cross ground ambulance.

"The field of EMS is relatively new," says Myers. "It started in the 1960s. Most of the information available is hospital-based research, but we are developing our own knowledge base now for emergency transport."

Stearns adds, "Mayo gives us the ability to conduct research and the tools needed to help a patient that are far beyond what other helicopter services can provide. Mayo does it right. Not everyone has Mayo Clinic's standards for quality and value."