Enhanced guidelines for evaluating and managing the symptoms of ailing airline passengers and increased awareness of high-risk groups could reduce the number of “futile diversions,” medical researchers say.1
A study published in the May issue of Aviation, Space, and Environmental Medicine (ASEM) also recommended the prescreening of some passengers recently discharged from hospitals, post-operative patients and people with specific terminal illnesses.
“Formulation of specific management guidelines for different symptom-based categories, grounded on evidence-based results, is the next step to establish specific action plans for flight attendants,” the study said. “Actions should be clearly delineated, and the role of coordination of available medical volunteers and the ground-based physicians clarified.”
In-flight medical kits with detailed guidelines on when and how to use specific medications and medical equipment also would aid both flight attendants and medical volunteers, the report said.
“The need for medical diversion is a balance between the proximity of ground resources and the availability of resources on board,” the document added. “This decision [on whether to divert a flight] requires more specialized training for cabin crew [and] medical professionals and enhanced tools for communication with ground-based medical advice services.”
The study examined data from 4,068 in-flight medical events that occurred at a large Hong Kong commercial airline from December 2003 through November 2008 and found that medical volunteers participated in 1,439 (35.4 percent) of the cases, including 39 (84.8 percent) of the 46 cases that resulted in an aircraft diversion.
Medical volunteers — who, in 77 percent of the cases, were doctors who had been flying as passengers — were more likely to be involved when the events were serious, the study said, noting that the airline’s policy was to call for volunteers only if recommended by MedLink, a ground-based medical advisory service, or if the passenger was obviously critically ill.
The study was designed to determine how medical volunteers functioned during in-flight medical emergencies and to identify strategies that might result in “more appropriate diversions,” the document said, noting, “Flight diversions are not only costly but also pose increased risks to the other passengers.”
These increased risks come as the flight crew travels to an unexpected destination and conducts what may be an unfamiliar instrument approach. In addition to safety risks, flight crews may need to dump excess fuel before an emergency landing, which can damage the environment and increase fuel consumption; and a diversion may result in costly delays for passengers and the operator.
Records allowed for further review of 36 of the 39 diversions, and of that number, 12 passengers were released, 16 were hospitalized, and eight died during the flight (Figure 1). Of those who were hospitalized, half were suspected of having had a stroke, two had chest pain and two went into labor.
Of seven diversions handled without medical volunteers, three passengers were released after emergency room evaluation, three were hospitalized, and one died during flight. Of those who were hospitalized, one each experienced pain, “nonspecific” symptoms and bleeding with no injury.
The study’s authors said they “cannot conclude that the presence of medical volunteers leads to more medical diversions. This remains an association, and there is no evidence to infer that volunteers directly cause more diversions.”
They added that the ratio of “appropriate diversions” was the same for patients on flights that were diverted after the intervention of medical volunteers and for those on flights where the decision to divert was made without a volunteer’s input.
Overall, suspected strokes (categorized as “nonspecific”) accounted for 25.6 percent of diversions, more than any other category, followed by chest pain (18.6 percent) and death (11.6 percent; Table 1).
Therefore, the study said, “it may be useful to incorporate simple pre-hospital stroke scales … into the training of the cabin crew.” Such assessment scales typically call for a simple evaluation of whether both sides of the face move equally or one side does not move, whether both arms can be moved equally or one arm drifts down, and whether speech is correct or the words are garbled or the passenger cannot speak.
In cases of chest pain, limited diagnostic equipment is available during flight, and treatment focuses on providing oxygen, aspirin and other medications to stabilize the passenger’s condition.
In the third category, “death,” all five diversions were diagnosed as cases of cardiac arrest. The study questioned whether a flight diversion is wise for patients who experience cardiac arrest during flight.
“The chances of a successful resuscitation in non-VF [cardiac arrest not involving ventricular fibrillation] out-of-hospital arrest are extremely low, even on the ground, and therefore the decision to medically divert should be taken very carefully,” the study said. “Considering the time it will take for the passenger to be taken to the hospital, diversion is only medically warranted if the patient responds to resuscitation, and not for every passenger with cardiac arrest.”
A separate study, published in the May 30 issue of the New England Journal of Medicine, reviewed 34 months of calls from five airlines to an unidentified medical communications center and found that the most frequent medical problems experienced by passengers were syncope (fainting) or presyncope (lightheadedness and weakness), 37.4 percent; respiratory symptoms, 12.1 percent; and nausea or vomiting, 9.5 percent.2
Hospitalizations most often were attributed to cardiac arrest, strokelike symptoms, obstetrical or gynecological symptoms and cardiac symptoms.
The study examined in-flight medical emergencies that prompted crewmembers to consult with medical experts on the ground — a situation that occurred at a rate of about 16 per 1 million passengers — or about one time in every 604 flights.3 The 11,920 calls, made from Jan. 1, 2008, through Oct. 31, 2010, to experts on the ground, resulted in aircraft diversions in 875 (7.3 percent) of the cases.
In 48.1 percent of cases, medical assistance came from physicians who were traveling as passengers. Nurses volunteered in 20.1 percent of cases, emergency medical services (EMS) providers in 4.4 percent, and other health care professionals in 3.7 percent of cases.
“Aircraft diversion and hospitalization rates differed according to the type of medical volunteer,” the report added, noting that, by a very slight margin, physicians had the highest diversion rates — 9.4 percent. In comparison, diversion rates for EMS providers were 9.3 percent; for nurses, 6.2 percent; and for crewmembers, 3.8 percent.
Hospitalization rates were highest for EMS providers — 10.2 percent — compared with 9.3 percent for physicians, 8.7 percent for nurses and 4.7 percent for flight crewmembers.
In-flight treatment most frequently involved providing oxygen (in 49.9 percent of cases), intravenous saline solution (in 5.2 percent) and aspirin (in 5.0 percent), the study said.
Aircraft diversion was most closely associated with use of an automated external defibrillator (AED) and assistance from an EMS provider, the study added, noting that records showed that AEDs were applied to 137 patients (1.3 percent). For the 134 patients with medical records detailed enough to allow further analysis, researchers determined that AEDs were used when the primary symptoms were syncope or presyncope, and chest pain; they also were applied in 24 cases of cardiac arrest. Of these, a shock was delivered to five patients. In nine cardiac arrest cases, cardiac activity resumed while the AED was being used, and all but one of the nine survived long enough to be admitted to a hospital. Eighty-four of the 134 patients treated with AEDs had lost consciousness.
In 42.1 percent of cardiac arrest cases, the flight was not diverted, the study said; in some of these cases, an immediate diversion was not possible because the airplane was on a transoceanic flight or near its planned destination.
Follow-up information was available for 10,914 patients, indicating that 3,402 (31.2 percent) needed no additional care after landing. Emergency medical services personnel were summoned for 7,508 patients, including 2,804 (37.3 percent) who were taken to a hospital emergency room; of those for whom follow-up information was available, 901 patients (8.6 percent) were admitted to the hospital or left the emergency room against the advice of medical personnel.
Reasons for Hospitalization
The most common reasons for admission, the study said, were cardiac arrest; stroke symptoms; obstetrical or gynecological symptoms, most often bleeding that signaled a possible miscarriage; and other cardiac symptoms.
Records showed that 36 of the 10,914 passengers died, including 30 who died during flight.
Overall, the study estimated that 44,000 in-flight medical emergencies occur every year. Most of these are “self-limiting or are effectively evaluated and treated without disruption of the planned route of flight,” the study said. “Serious illness is infrequent, and death is rare.”
Like the ASEM report, the Journal study noted that some airlines require flight attendants to consult with a ground-based physician before using the emergency medical kit in the airplane.
“Passengers’ symptoms can often be managed in collaboration with the flight attendants, who are well versed in the equipment that the airplanes carry and in operational procedures,” the study said. “When the need for evaluation or intervention exceeds their capabilities, flight attendants may seek health care professionals on the flight.”
The study recommended establishing step-by-step procedures for coping with the most common in-flight medical emergencies — syncope, respiratory symptoms, nausea or vomiting, and cardiac symptoms.
For example, the study said that patients with syncope, who may initially be unresponsive and have low blood pressure, usually improve in about 15 minutes with no treatment other than fluids, administered by mouth or intravenously.
Cases of heart attack, stroke or “other factors that raise concern about time-sensitive conditions,” including passengers with “persistently altered mental status,” should prompt the crew to consider a diversion, the study said.
Providing medical treatment during flight can be challenging, in part because of the limited availability of space and medical equipment, the study said.
Nevertheless, the document added, “diversion of a commercial airliner to an unscheduled destination for an ill passenger requires consideration of both medical and operational issues. The potential medical benefit should be assessed on the basis of the condition and its time sensitivity, the ability to stabilize the patient’s condition with available supplies and the likely time savings with consideration of the time needed to land and the proximity of medical resources to specific airports. Immediate operational factors that may contribute to variability in airline practices include weather, fuel load and the potential need to drop fuel before landing, the availability of specific aircraft services at airports and air traffic control.”
The study called for the “systematic tracking of all in-flight medical emergencies, including subsequent hospital care and other outcomes, to better guide interventions in this sequestered population.”
- Hung, Kevin K.C.; Cocks, Robert A.; Poon, W.K. et al. “Medical Volunteers in Commercial Flight Medical Diversions.” Aviation, Space, and Environmental Medicine Volume 84 (May 2013): 491–497.
- Peterson, Drew C.; Martin-Gill, Christian; Guyette, Francis X. et al. “Outcomes of Medical Emergencies on Commercial Airline Flights.” New England Journal of Medicine Volume 368 (May 30, 2013): 2075–2083.
- Participating airlines accounted for about 10 percent of passenger flight volume worldwide for the time period studied.