A national survey of the air medical transport of high-risk obstetric patients

INTRODUCTION: Air medical transport of high-risk obstetric (HROB) patients can be accomplished and advantageous for neonate survival and maternal morbidity. A survey of U.S. helicopter air medical programs was conducted to determine the frequency and current practices of HROB transport. METHODS: Each program was contacted by telephone, and air medical personnel were asked to answer 12 questions based on personal experience and statistics compiled by their programs. RESULTS: Of the 203 programs surveyed, 133 (66%) provided responses. The mean number of HROB transports was 45.6 per year (4.6% of the mean 995 total transports). Although 83% of the responding programs used the standard flight crew during the HROB transport, only 52% required crew members to maintain neonatal resuscitation certification. Only 56% of the aircraft allow pelvic access in the normal patient configuration. While only 22% of programs have specific HROB launch (dispatch) protocols, 50% reported having obstetricians involved in dispatching flights, and 84% carry tocolytic agents in their drug kit. The greatest concerns included in-flight delivery (60%), inadequate fetal monitoring (6%), and inexperience (5%). CONCLUSION: While HROBs account for 5% of air medical flights, many programs appear to be poorly prepared for these patients.     

Training of flight nurses on fixed-wing air ambulance services

Introduction: The purpose of this study was to determine the background of fixed-wing air ambulance nurses, what level of training they receive before assignment as a flight nurse, and how closely supervised these fixed-wing air ambulance programs are by their medical directors.

Methods: In 1993, a retrospective statistical questionnaire was sent to 113 fixed-wing air ambulance programs. Chief flight nurses for all 113 fixed-wing air ambulance transport companies were requested to complete a written survey consisting of 17 multiple choice and fill-in-the-blank questions about previous experience, flight nurse qualifications, and content covered in their initial training program.

Results: Of 113 surveys, 72 (64%) responded. The majority (87%) of the flight crew were 30 to 39 years of age. The crew mix is RN/EMT-P in 49%, RN/RN in 25%, and RN/RT in 25%. Experience before flying showed emergency department/intensive care unit in 87% with 13% specialized to a specific type of patient care. The initial training in classroom hours was less than 21 hours in 50% of programs. Training programs were taught by the chief flight nurse in 75%, the medical directors in 74%, and outside organizations in 30%. Fifty-five percent of programs use pilots or other flight crew members to supplement initial training. Only eight of the programs did not have yearly refresher classes. Programs providing more extensive training appear to be affiliated with hospital-based services. Medical directors were involved with the everyday running of air medical transports in 35 of the pro grams (50%), 20 medical directors (28%) did monthly chart reviews only, and 12 (17%) were not involved with their programs. There were three responses to “Other” and two with no responses.

Conclusions: Although fixed-wing flight nurses appear to be medically experienced personnel with previous intensive care unit or emergency department experience, this survey would suggest that fixed-wing flight programs are variable in the amount of initial training, level of instructors, ongoing medical education, and involvement of the medical director. This survey indicates the need for increased standardization of continuing education, as well as increased involvement of medical directorship in fixed-wing air ambulance services.     

Long-distance transport of ventilated patients: advantages and limitations of air medical repatriation on commercial airlines

INTRODUCTION: To illustrate the advantages and limitations of transporting ventilated intensive care unit patients over intercontinental distances on commercial airlines, this case series reports 8 ventilated patients repatriated by an air medical transport company. PATIENTS: Eight ventilated patients, 3 suffering from internal and 5 from neurologic diseases. Distances ranged from 1700 to 10280 nautical miles with transport times from 04:10 hours to 21:55 hours. For 3 patients, a dedicated patient transport compartment (PTC) in the aircraft cabin was used. All patients were ventilator-dependent for a minimum of 11 days before transport (48 days median, 113 days maximum). RESULTS: One patient went into cardiac arrest during the flight and died. None of the other patients experienced any emergency or invasive procedures, other than peripheral venous access necessary during the flight. In all patients, ventilation was adjusted with respect to the blood gas analysis at least once during the transport. No technical failures or drop-outs occurred during the flights. None of the flights had to be diverted for technical or medical reasons. CONCLUSION: Long distance international transport of ventilated intensive care unit patients is an extremely cost intensive and logistically challenging task. In a certain subgroup of relatively stable ventilated patients, transport on commercial airlines offers advantages in terms of cost effectiveness and reduced transport time and acceleration/deceleration trauma as a result of multiple fuel stops.     

Monitoring the appropriateness of air medical transports

INTRODUCTION: With pending changes in the health-care system, there are increasing pressures for each aspect of health care to justify its use. Several organizations, including the Association of Air Medical Services (AAMS), have published position papers listing appropriate indications for air medical services. Additionally, the Commission on Accreditation of Air Medical Services (CAAMS) specifies that air medical services monitor their flights for appropriateness. The purpose of this study was to determine how often the air medical transports by this program met at least one of the AAMS criteria. METHOD: The AAMS position paper was paraphrased into an equivalent checklist and a category, "None of the above criteria met," was added. Immediately after each transport, a flight nurse indicated on the checklist which criteria the patient met supported by documentation in the flight care record. RESULTS: During a one-year period (March 1, 1992 through February 28, 1993), 558 patients were transported. Of these, 547 (98%) met at least one of the AAMS appropriate-use criteria. CONCLUSION: The AAMS "Appropriate Use of Air Medical Services" position paper provides a foundation to monitor the utilization of an air medical transport program, which can be used to meet both government payer requirements for justification and the CAAMS requirement for utilization review.     

Influence of the helicopter environment on patient care capabilities: flight crew perceptions

INTRODUCTION: Flight crew perceptions of the effect of the rotary-wing environment on patient-care capabilities have not been subject to statistical analysis. We hypothesized that flight crew members perceived significant difficulties in performing patient-care tasks during air medical transport. METHODS: A survey was distributed to a convenience sample of flight crew members from 20 flight programs. Respondents were asked to compare the difficulty of performing patient-care tasks in rotary-wing and standard (emergency department or intensive care unit) settings. Demographic data collected on respondents included years of flight experience, flights per month, crew duty position and primary aircraft in which the respondent worked. Statistical analysis was performed as appropriate using Student's t-test, type III sum of squares, and analysis of variance. Alpha was defined as p < 0.05. RESULTS: Fifty-five percent of programs (90 individuals) responded. All tasks were significantly rated more difficult in the rotary-wing environment. Ratings were not significantly correlated with flight experience, duty position, flights per month or aircraft used. CONCLUSIONS: We conclude that the performance of patient-care tasks are perceived by air medical flight crew to be significantly more difficult during rotary-wing air medical transport than in hospital settings.     

Pilot study for predicting appropriate use of air medical helicopters. Part 1: Interfacility transports

Introduction: Appropriate use of rotor-wing aircraft is an important issue to the emergency transport industry. The purpose of this pilot study was to test criteria for their ability to accurately identify patients for whom interfacility helicopter transport is appropriate.Methods: Flight data collected from 219 flights included measures of physiological status, interventions, and need for timely care. Appropriate and inappropriate flights were compared using chi-square, Mann-Whitney U, and Wilcoxon matched-pairs signed rank tests. Logistic regression was used to evaluate how well information at critical decision points distinguishes between appropriate and inappropriate flights.Results: Statistical difference occurred between appropriate and inappropriate flights for the variables of preflight cardiac status, preflight interventions, preflight total score, flight crew vital signs, flight crew cardiac status, flight crew interventions, flight crew total score, need for surgical intervention, and need for complex critical care. No statistical difference existed between appropriate and inappropriate flights for the variables of preflight vital signs, preflight neurologic status, and flight crew neurologic status. Logistic regression models showed that coefficients for preflight total score, flight crew interventions, flight crew total score, need for surgical intervention, and need for complex critical care were significant. All other coefficients were not significant. Patients requiring emergent surgical intervention were more than four times likely to be considered an appropriate use of the aircraft, and patients requiring complex critical care were almost eight times more likely to be considered an appropriate use of the aircraft. Odds ratios for preflight and flight crew total scores revealed an increase in the likelihood of appropriateness as the total score values increased.Conclusion: Development of a gold standard to determine appropriate use of the aircraft and measurable criteria on which to base that decision is important. The instrument used in this pilot study now must be revised given statistical findings and input from the emergency transport industry.     

Anxiety in adult fixed-wing air transport patients

INTRODUCTION: Critically ill patients may experience anxiety because of the method of transport, possibly having an impact on both patients and their health care providers. The purpose of this research was to study the presence and degree of anxiety in fixed-wing air transport patients. METHODS: Subjects were 41 patients 25 to 79 years of age. Self-ratings of anxiety were obtained and vital signs were recorded at five predesignated points before, during, and after the flight. Additional questions addressed current and previous experiences and perceptions of flying. RESULTS: Anxiety ratings were generally low, averaging approximately 1.9 on a 1 ("worry-free") to 10 ("completely terrified") scale. Anxiety was greatest in anticipation of the flight. Fourteen percent of patients had never flown before; patients with little or no flight experience had significantly higher anxiety ratings. However, in all cases anxiety declined steadily as the flight progressed. Most patients (82%) reported greater worry about their medical condition than about the flight. CONCLUSION: Anxiety is generally low among adult fixed-wing air transport patients and decreases further over time. This decrease was true even for patients who initially reported high levels of anxiety before the flight. The data suggest that previous flight experience can be used to predict anxiety during air medical transport.     

A nationwide survey of civilian air ambulance services

To identify and characterize civilian air ambulance services, a questionnaire was mailed nationwide to 583 prospective air ambulance services, with 154 responding. Our survey identified differences between hospital, hospital-affiliated, and private air ambulance services as to aircraft ownership, availability, types of aircraft, types of patients being transported, types of medical personnel and equipment, aircraft retrofit, and their feelings regarding air ambulance regulations. We found that hospital air ambulances are better suited for transporting critically ill patients while many private air ambulances appear better suited to transport nonemergency patients. Hospital-affiliated air ambulance services, although not as consistent in providing the specialized care of hospital air ambulances, appear better able to provide critical care than private air ambulance services. Based upon this data, we recommend that air ambulance regulations be directed at levels of patient care. Such regulations and guidelines will assist patient safety during aeromedical transports without jeopardizing currently operating air ambulance services.     

Air ambulance regulations: a model

Prior attempts at establishing minimal federal air ambulance regulations and standards have been unsuccessful. However, reports of poor patient medical care during transport by some air ambulance services is now forcing many states to initiate air ambulance regulations. In 1984, the State of Utah Emergency Medical Services convened a special subcommittee to develop aeromedical regulations for the State of Utah. Using a three-level approach based upon the patient's requirements for basic, advanced, or specialized medical care and the urgency of transport, the subcommittee was able to derive medical categories necessary for the selection and utilization of air ambulance services. Minimum air ambulance regulations were then established for aircraft configuration, flight crew requirements, minimal equipment and medications, and the responsibilities of the medical director or designee for each of the three levels of medical care. We conclude that the application of a levels approach based upon the patient's medical requirements may be useful in assisting other states attempting to establish flexible but specific regulations directed at the safe transport of patients by aeromedical evacuation.     

The effect of single engine fixed wing air transport on rate-responsive pacemakers.

BACKGROUND: Insufficient information exists about the safety of patients with accelerometer-based rate-responsive pacemakers in air transport by general aviation aircraft. METHODS: The response in pacing rate of two types of accelerometer-based rate-responsive pacemakers with data logging capabilities was studied during test flights with single engine fixed wing aircraft. Results were compared with the rate-response of these pacemakers during transportation by car and were also interpreted in respect to physiological heart rate response of aircrew during flights in single engine fixed wing aircraft. In addition, a continuous accelerometer readout was recorded during a turbulent phase of flight. This recording was used for a pacemaker-simulator experiment with maximal sensitive motion-sensor settings. RESULTS: Only a minor increase in pacing rate due to aircraft motion could be demonstrated during all phases of flight at all altitudes with the pacemakers programmed in the normal mode. This increase was of the same magnitude as induced during transport by car and would be of negligible influence on the performance of the individual pacemaker patient equipped with such a pacemaker. Moreover, simultaneous Holter monitoring of the pilots during these flights showed a similar rate-response in natural heart rate compared with the increase in pacing rate induced by aircraft motion in accelerometer-based rate-responsive pacemakers. No sensor-mediated pacemaker tachycardia was seen during any of these recordings. However, a 15% increase in pacing rate was induced by severe air turbulence. Programming the maximal sensitivity of the motion sensor into the pacemaker could, on the other hand, induce a significant increase in pacing rate as was demonstrated by the simulation experiments. CONCLUSION: These results seem to rule out potentially dangerous or adverse effects from motional or vibrational influences during transport in single engine fixed wing aircraft on accelerometer-based rate-responsive pacemakers with normal activity sensor settings.     

Clinical risk factors for venous thrombosis associated with air travel

BACKGROUND: Recent reports have linked air travel with venous thrombo-embolism (VTE). Risk factors and associated features of this link are poorly understood. We have accumulated clinical data from a relatively large cohort of patients with traveler's thrombosis. METHODS: A total of 86 patients who developed venous thromboembolism within 28 d of flying were questioned concerning traveling habits, medical history (including risk factors for VTE) and characteristics of the index flight. RESULTS: Of the patients, 72% had at least one risk factor for VTE (excluding thrombophilia) prior to their flight. Of interest, 87% of VTE cases occurred following either a return trip or after an outward journey involving long trips made up of sequential flights. In only two cases could no identifiable risk factor or earlier journey be found. Duration of flights ranged from 2 to 30 h. Of responders, 38% presented with chest symptoms; 92% with VTE developed symptoms within 96 h of their flight. CONCLUSION: We conclude that the majority of VTE associated with air travel occur in those with identifiable risk factors prior to their flight, and that sequential flights may increase this risk.     

Preliminary results of medical studies during the 5-month space flight aboard the "Saliut-7"--"Soiuz-T" orbital complex

The medical examinations carried out in the 150-day flight were a continuation of the previous studies in terms of the approaches and methods used. The novel approach was a biochemical study of body fluids collected during flight. An important place was occupied by during EVA. The medical results of the 150-day flight were in consistency with the data obtained during previous space flights of similar duration. The health condition and work capacity of the crewmembers throughout the flight (including two EVA events) were good. The changes seen during and after flight were adaptive and disappeared after a relatively short readaptation period.     

Use of local climatic data to determine if weather precludes the operation of an air medical system

INTRODUCTION: Weather is one of many factors that affect safety in an air medical program. Syracuse, New York, has notoriously bad weather, and some have questioned whether an air medical service is practical given central New York's climate. This study was undertaken to determine the extent to which the area's climate could be expected to limit the availability of an air medical service. METHODS: CAMTS weather minimums for rotor-wing programs were compared with 1996-1997 hourly weather observations from the Northeastern Regional Climate Center (NRCC) and sunrise/sunset data from the United States Naval Observatory to determine how frequently weather conditions could be expected to preclude an air medical response in the greater Syracuse area. RESULTS: Exactly 17,544 hourly observations were made. CAMTS weather minimums would have precluded local flights for 606 (3.5%) of these hours and cross-country flights for 1111 (6.3%) hours. Cross-country flights were more likely to be precluded than local flights (P = .001), and both local and cross-country flights were more likely to be precluded at nighttime than in the daytime (P = .001). All flights were more likely to be precluded during winter months than during summer months (P = .000). CONCLUSION: The weather in central New York generally does not preclude the operation of an air medical services system.     

Safety of fentanyl for analgesia in adults undergoing air medical transport from trauma scenes

Introduction: Although proper analgesia provision for patients in the in hospital acute setting has received recent attention, little discussion has been done of prehospital pain relief. This study was conducted to evaluate the safety of fentanyl administration during air medical transport of adult trauma patients.Setting: Urban air medical transport program using a flight nurse/paramedic crew operating with patient care protocols and off-line medical control.Methods: Flight records for trauma patients transported directly from the scene receiving fentanyl were analyzed retrospectively. Study parameters were obtained for the times just preceding and after fentanyl administration. A t test (α = 0.05) comparison between before and after fentanyl administration was performed for the following study parameters: systolic blood pressure, heart rate, oxygen saturation, respiratory rate, and Glasgow coma score in non-intubated patients. Flight records were also reviewed for any administration of naloxone or subjective notation of complications possibly attributable to fentanyl.Results: Fentanyl was administered 154 times to 99 patients. No patient received in-flight naloxone, and no fentanyl-related complications were noted on flight record review.Conclusion: Administration of fentanyl for in-flight trauma analgesia in adults seems safe. Further study should investigate efficacy of in-flight fentanyl administration and determine whether prehospital opiate administration impairs emergency department evaluation of trauma patients.     

Cabin environment and perception of cabin air quality among commercial aircrew

OBJECTIVE: Our objective was to study the perception of cabin air quality (CAQ) and cabin environment (CE) among commercial cabin crew, and to measure different aspects of CAQ on intercontinental flights. METHODS: A standardized questionnaire was mailed in February-March 1997 to all Stockholm-based aircrew on duty in a Scandinavian flight company (n = 1,857), and office workers from the same company (n = 218). The answers were compared with an external reference group for the questionnaire (MM 040 NA). During this time, smoking was allowed on intercontinental flights, but not on other shorter flights. Smoking was prohibited on all flights after 1 September 1997. The participation rate was 81% (n = 1,513) in the aircrew, and 77% (n = 168) in the office group. Air humidity, temperature, carbon dioxide (CO2) and respirable dust were measured during intercontinental flights, during both smoking and nonsmoking conditions. Statistical analysis was performed by multiple logistic regression analysis, keeping age, gender, smoking, current smoking, occupation, and perceived psychosocial work environment simultanously in the model. RESULTS: Air humidity was very low (mean 5%) during intercontinental flights. In most cases (97%) the CO2 concentration was below 1,000 ppm. The average concentration of respirable particles was 67 microg x m during smoking conditions, and 4 microg x m(-3) during non-smoking conditions. Complaints of draftiness, too high temperature, varying temperature, stuffy air, dry air, static electricity, noise, inadequate illumination, and dust were more common among aircrew as compared with office workers from the same company. Female crew had more complaints on too low temperature, dry air, and dust. Current smokers had less complaints on stuffy air and environmental tobacco smoke (ETS). Younger subjects and those with atopy (childhood eczema, allergy to tree or grass pollen, or furry animals) reported more complaints. Reports on work stress and lack of influence on working conditions were strongly related to perception of a poor cabin environment. Flight deck crew had more complaints about inadequate illumination and dust, but less complaints about other aspects of the cabin environment, as compared with flight attendants. Aircrew who had been on a flight the previous week, where smoking was allowed, had more complaints on dry air and ETS. CONCLUSION: Complaints about work environment seems to be more common among aircrew than office workers, particularly draft, stuffy air, dry air, static electricity, noise, inadequate illumination and dust. We could identify personal factors of importance, and certain conditions that could be improved, to achieve a better perception of the cabin environment. Important factors were work stress, lack of influence on the working conditions, and environmental tobacco smoke on some longer flights. The hygienic measurements in the cabin, performed only on intercontinental smoking flights, showed that air humidity is very low onboard, and tobacco-smoking onboard leads to significant pollution from respirable dust.