Air Medical Program Research Articles

COMPARISON OF ETOMIDATE AND MIDAZOLAM FOR PREHOSPITAL RAPID-SEQUENCE INTUBATION

Objective. This study compares etomidate with midazolam for prehospital rapid-sequence intubation (RSI). Methods. The authors conducted a retrospective review of consecutive intubations at a university-based air medical program from January 1995 to December 2000. Exclusion criteria were patients not undergoing RSI, age <15 years, and incomplete chart data. Outcome measures included intubation success, incidence of hypotension, and percentage of change in heart rate (HR) and systolic blood pressure (SBP). Results. The intubation success rate was 110 out of 112 (98%) with etomidate, and 96 out of 97 (99%) with midazolam. Mean ages, patient gender distributions, and initial SBPs and HRs did not differ between the two groups. The mean dose of etomidate was 24 mg, the mean percentage of change in HR was −1% (95% confidence interval [CI], −6 to 4), and the mean percentage of change in SBP was 2% (95% CI, −3 to 7). The mean dose of midazolam was 3.5 mg, the mean percentage of change in HR was 1% (95% CI, −5 to 7), and the mean percentage change in SBP was 3% (95% CI, −3 to 9). The number of hypotensive episodes with etomidate (7 out of 74) compared with midazolam (3 out of 56) did not differ significantly (Fisher's exact test, p = 0.51). Conclusion. Intubation success rate was very high with both etomidate (98%) and midazolam (99%). There was no statistically significant mean percentage of change in SBP or HR with either agent. The authors found a low incidence of hypotension with both agents, although the mean dose of midazolam used was considerably less than typically recommended for induction.

Comparison of the intubating laryngeal mask airway versus laryngoscopy in the Bell 206-L3 EMS helicopter

Introduction The purpose of this study is to compare intubation success rate and time to intubation for the intubating laryngeal mask airway (I-LMA) versus direct laryngoscopy (DL) using a manikin model during a simulated in-flight scenario. Setting The setting for the study was a University hospital-based air medical program. Methods This was a prospective, randomized, crossover trial. Eight nurses and 7 paramedics were randomly assigned to perform 3 intubations with either the I-LMA or DL first and then 3 intubations using the alternate technique. Descriptive statistics, 95% confidence intervals (CIs) of means, and Fisher's Exact test were conducted for comparisons. Results Fifteen set-ups and 45 intubations were performed with each technique. Previous experience was 74 mm (95% CI 64-84) with DL and 18 mm (95% CI 9-27) with the I-LMA. Set-up time was 33 seconds (95% CI 26-40) for DL and 40 seconds (95% CI 29-50) for I-LMA. Time to intubation was 12 seconds (95% CI 10-14) for DL and 39 seconds (95% CI 31-48) for I-LMA. Success rate was 100% for DL and I-LMA placement and 98% for intubation through the I-LMA. Crew rated difficulty of DL 13 mm (95% CI 6-20), placing the I-LMA 23 mm (95% CI 13-32), and intubating through the I-LMA 17 mm (95% CI 10-24). Conclusion Intubation success was very high for both DL and the I-LMA, despite less flight crew experience with the I-LMA. Total time to intubation was longer with the I-LMA but still less than 1 minute. The flight crews considered both techniques easy to perform. The I-LMA appears to be a useful adjunct for airway management in the Bell 206-L3 helicopter.

Comparison of intubation attempts and completion times before and after the initiation of a rapid sequence intubation protocol in an air medical transport program

The purpose of this study was to test the hypothesis that the initiation of a rapid sequence intubation (RSI) protocol would decrease the number of intubation attempts and completion times. In the summer of 2001, an RSI protocol was implemented using succinylcholine and etomidate. Before the RSI protocol, patients were sedated with versed and fentanyl for intubation and then paralyzed with succinylcholine to complete intubation, if needed. Retrospectively reviewed patient transport charts yielded 70 patients in the pre-RSI group and 70 patients in the RSI group. The number of attempts in the RSI group significantly dropped in the pre-RSI group, and the time from medication administration to intubation statistically decreased. In this study, the implementation of an RSI protocol resulted in fewer intubation attempts and more rapid intubations.

Presumption of death by air medical transport teams.

The purpose of this study was to investigate nationwide trends and factors influencing the determination of death practice by rotor-wing air medical transport programs. A survey was mailed to all Association of Air Medical Service members concerning demographics, crew configuration, team leader, patient population, field death determination protocols, and other possible associated factors. All rotor-wing air medical transport programs that carry out scene transports were included. The most common field presumption criteria were no response to advanced cardiac life support (77%), no signs of life on scene (65%), and asystole in 2 EKG monitor leads (61%). The most frequent reasons cited not to presume a patient dead in the field were political issues (71%) and signs of life on scene (56%). Criteria other than medical condition that were considered in the decision to presume death were ground personnel input (55%) and program policy/medical control (39%). The following factors did not significantly affect the presumption rate: crew configuration, team leader, transport time, billing, and type of medical control. Medical criteria appear to determine presumption of death in the field. Nonmedical factors, such as billing, response, and transport times, do not affect this process.

Presumption of death by air medical transport teams

Background: The purpose of this study was to investigate nationwide trends and factors influencing the determination of death practice by rotor-wing air medical transport programs. Methods: A survey was mailed to all Association of Air Medical Service members concerning demographics, crew configuration, team leader, patient population, field death determination protocols, and other possible associated factors. All rotor-wing air medical transport programs that carry out scene transports were included. Results: The most common field presumption criteria were no response to advanced cardiac life support (77%), no signs of life on scene (65%), and asystole in 2 EKG monitor leads (61%). The most frequent reasons cited not to presume a patient dead in the field were political issues (71%) and signs of life on scene (56%). Criteria other than medical condition that were considered in the decision to presume death were ground personnel input (55%) and program policy/medical control (39%). The following factors did not significantly affect the presumption rate: crew configuration, team leader, transport time, billing, and type of medical control. Conclusion: Medical criteria appear to determine presumption of death in the field. Nonmedical factors, such as billing, response, and transport times, do not affect this process.

A flight orientation curriculum for emergency medicine resident physicians.

Introduction Prehospital experience with emergency medical services (EMS) is a valuable and essential aspect of emergency medicine residency training. A physical experience in the prehospital environment yields numerous educational benefits including increased familiarization with EMS operations, increased awareness of situations faced by prehospital providers, involvement as an EMS educator, increased competency with base radio communication, exposure to disaster planning, and an opportunity for EMS research. A specialized realm of prehospital care is air medical transport. Although not explicitly required for residency program accreditation, participation in air medical transport is recommended and represents a valuable addition to the residents’ EMS education. According to a 2000 Airmed survey, 9% of air medical programs fly with resident physicians on a full or part time basis. West Michigan Air Care is a critical care rotor-wing transport program in Kalamazoo staffed by nurses and paramedics. In 1994, the program began integrating secondand thirdyear emergency medicine residents from Michigan State University Kalamazoo Center for Medical Studies into its flight program as additional members of the medical team. This article describes the orientation program that we developed for emergency medicine resident physicians to introduce them to air medical program operations, direction, and utilization.

Air Medical Transport of Cardiac Patients in Nova Scotia

Objective : To perform a descriptive program review of the air medical transport (AMT) of cardiac patients within Nova Scotia's air medical transport program. Methods : A retrospective study of patients with primary, non-traumatic cardiac conditions transported by the provincial air ambulance program between August 1, 1997 and August 31, 1998, who are 16 years of age or older (non-pediatric). Various aspects were examined, including diagnosis, geography of transport, medications given by the air medical crew (AMC) and by sending institution, complications of transport and interventions performed by the AMC as well as total time spent at the sending institution by the AMC. Data was extracted from the flight patient care records (PCR) with full preservation of patient confidentiality. Results : The AMT program transported a total of 240 patients during the study period. Of these a total of 155 patients (64.6%) were 16 years of age or older. Of that total, 46 had a primary cardiac diagnosis (29.7%): 34 were male (73.9%) and 12 were female (26.1%). The mean age of these transported patients was 62.4+/-10.0 ears and 59.1+/-17.6 years for males and females respectively. Most cardiac patients were diagnosed with a myocardial infarction (22 patients, 47.8%), with the remaining patients diagnosed with unstable angina, peri-cardiac arrest, congestive heart failure (CHF) or primary arrhythmia. Only 12 of the patients diagnosed with myocardial infarction (MI) had previously been treated with thrombolytics (54.5%). Heparin and intravenous nitroglycerine were the medications most commonly maintained by the AMC, while morphine, midazolam, nitroglycerine and dimenhydrinate were common medications given by the AMC. Twenty-three patients experienced some form of in-flight complication or change in condition, with brady- arrhythmias being the most common (23.9%). Nine patients were intobated by the referring hospital or by the AMC prior to departure and maintained as such throughout the flight. The average amount of time spent at the referring hospital packaging each patient was 64.07 minutes. Conclusions : This paper describes the demographics of the cardiac population utilising air medical transport in Nova Scotia. Cardiac patients comprise a large proportion of the total patient cohort in the AMT program (almost one-third) in the adult population transported. Recognition of this fact, in conjunction with review of provincial, tertiary-care, cardiac transfer policies has led to the development of specific cardiac AMT indications for Nova Scotia.

L ONG-TERM A IR M EDICAL S ERVICES S YSTEM P ERFORMANCE U SING APACHE-II AND M ORTALITY B ENCHMARKING

Objective. Air medical transport programs have been in existence for two decades. During this time, no outcome measures have been developed for these services. The authors examined severity scoring and mortality data from their air medical service to characterize its performance and to identify trends in acuity and mortality over a 15-year period. Methods. APACHE-II scores derived at the time of transport and hospital mortality data have been concurrently recorded in the flight database for adult transports since 1986. The authors analyzed these data and examined the correlation between APACHE-II score at the time of transport and hospital mortality for the 15-year period 1986-2001. Results. 13,808 adult transports were identified. APACHE data were available for 8,204 patients (59%) and mortality for 10,845 (79%), respectively. The number of transports increased from 935 to 1,231 per year. Mean APACHE-II for all patients was 11.6 ± 8.4. Overall mortality was 22%. Both patient acuity and mortality were trending upward over time. The correlation between APACHE-II and mortality was close and linear (mortality = 0.018 • APACHE-II - 0.0243, R2 = 0.97). Conclusions. Both severity of illness and mortality of air-transported patients appear to be increasing slowly over time in response to changes in the health care system. The strong correlation between APACHE-II performed at the time of transport and mortality validates this technique for benchmarking. The slope of this correlation is an outcome-based characteristic of system performance that may allow monitoring of a system over time and comparisons between systems.

2002 Directory of Air Medical Programs

2002 Directory of Air Medical Programs

Geriatric air medical transport: A program review

Introduction: The purpose of this study is to descriptively review the air medical transport of geriatric patients within the provincial air medical program of Nova Scotia. Methods: This study was based on a retrospective review of charts from March 14, 1996, to February 24, 1998, and included patients 65 years or older transported by air ambulance. All trauma and nontrauma missions were included in the program's adult services component (more than 15 years old). The total population served is approximately 1 million. Results: Fifty-nine geriatric patients were transported from a total of 175 adult missions during the study period, representing 33.7% of the adult services total. Nontrauma missions numbered 48 (81.3%), with the remainder (11, 18.6%) being trauma. Overall mortality in our study cohort was 32.2%. Conclusion: Air medical transport usually is associated with trauma transport of the younger patient. This program review demonstrates that one-third of adult air medical transports in this province are for patients older than 65 who are critically ill, though often with nontrauma conditions, and are associated with a high mortality rate. Air medical transport programs should have strategies, education, and protocols that reflect the unique pathophysiology of the elderly.

Effect of an airway education program on prehospital intubation

Introduction: The purpose of this study was to determine the impact of an airway education program (AEP) on prehospital intubation. Setting: University-based air medical program Methods: Retrospective review of 372 consecutive intubations for 3 years before and 3 years after the institution of an AEP. Descriptive statistics were used and comparisons were made using chi-square analysis. Results: Intubation success rate was 170/180 (94%) for the preAEP group and 186/192 (97%) for the postAEP group ( P > 0.05). Neuromuscular blockade (NMB) was used in 113/180 (63%) of preAEP intubations and 145/192 (76%) of postAEP intubations ( P < 0.01). NMB without sedation decreased from 62/113 (55%) in the preAEP group to 12/145 (8%) in the postAEP group ( P < 0.001). Cricothyrotomy rate decreased from 10/180 (6%) in the preAEP group to 3/192 (2%) in the postAEP group ( P < 0.05). Failed intubation rate in nonarrested patients during the 6-year period was 10/154 (6%) in patients receiving no medications or partial rapid sequence intubation (RSI) compared with 3/184 (2%) in patients who had full RSI ( P < 0.025). Conclusion: Establishment of an AEP resulted in an increase in NMB for intubation, a dramatic decrease in the use of NMB without sedation, and a decrease in cricothyrotomy rate. The rate of intubation failure in nonarrested patients was higher in those who received no medications or partial RSI compared with full RSI.

Air medical transport at its peak—AirLife of Greeley

Based in northeastern Colorado, AirLife of Greeley is a rotor-wing air medical program serving Colorado, Wyoming, and Nebraska from the crisp altitudes of the Rocky Mountains to the windblown plains where temperatures can rise above 100°. July 1, 2002, marks the 20th anniversary of our rural helicopter service. We credit our longevity and growth to a combination of factors, including educational outreach programs, a staff dedicated to excellence, and a commitment to safety.

Air medical transport of suspected aortic emergencies

Purpose: To review and characterize 4 years of experience with suggested nontraumatic aortic emergencies (dissections/ruptures) transported by a new, provincially dedicated rotor-wing air medical program Methods: Retrospective 4-year review of air medical program's mission records and review of related hospital records. Patients listed as suspected aortic emergencies (nontraumatic) in the air medical records were included. Mission records were reviewed for EMS diagnosis, blood pressures before and after transport, transport times, and mortality. Hospital records were reviewed for diagnosis, interventions/treatment, and mortality. Blood pressures below 80 mmHg systolic were considered hemodynamically unstable. Results: A cohort of 34 patients were identified, of whom 31 (91%) arrived at the hospital alive. Twenty-five patients (74%) arrived hemodynamically stable, with a mean out-of-hospital time of 60 minutes, and nine patients (26%) were hemodynamically unstable (mean out-of-hospital time was 54 minutes). No significant difference arose in times between these two groups ( P = 0.16). Overall mortality was 53% (18). Differences in transport time between survivors and deaths was not statistically significant ( P = 0.93). The diagnoses on admission to hospital: 14 (41%) were RAAA, five (15%) AAA no rupture, eight (24%) aortic dissections, and four (12%) had no aortic pathology. Seventeen patients (50%) received emergent surgical intervention. The EMS diagnosis was correct in 76% of cases. Conclusion: Our program transported 34 suspected aortic emergencies of which 17 were immediate surgical candidates on arrival. Aortic emergencies are not infrequent within our program. Specific policies and procedures based on continuing quality review should be in place to optimize the transport and care of these patients.

Interfacility Transports

Financial pressures exerted by managed care organizations toward hospitals to improve efficiencies and to lower total healthcare costs continue to force physicians and administrators to reevaluate operations and practices. This shifting of risk exposure from insurers to providers has resulted in many mergers, acquisitions, and affiliations, so as to form integrated health systems that reduce repetition and duplication of services. Therefore, as these integrated systems develop, along with the emergence of tertiary care, regional referral, and specialty hospitals, the need for patient transfers between such facilities will expand. The decision to move patients between facilities is a multicomponent process comprising health, safety, financial, and legal concerns. Interfacility transportation of patients has been performed over the past 20 to 30 years. Whereas ground transport services were prominent in the 1970s, air medical programs using helicopters and fixed-wing aircraft have recently become widespread. Both hospital-based and private agencies have continued to develop programs for efficiently and expeditiously transporting critically ill or injured patients, many requiring complex life-support devices. The Practice Management Committee of the American College of Emergency Physicians recently updated the 1990 policy statement on interfacility transfers, and two position statements are available from the National Association of EMS Physicians on criteria for air medical transport and medical direction for interfacility transport services. This review provides an overview of transportation systems and services available and assists physicians in understanding the various modes and characteristics of systems available. Personnel configurations and capabilities, physiological limitations, inherent requirements for equipment and patient preparation, and legal issues involved with transferring patients are also outlined.

M EDICAL D IRECTOR FOR A IR M EDICAL T RANSPORT P ROGRAMS

The NAEMSP recognizes the multifaceted and integral position of a medical director for an air medical transport program and the EMS community at large.

Forum: AAMS, AMPA, ASTNA, NEMSPA, NFPA

Forum: AAMS, AMPA, ASTNA, NEMSPA, NFPA

Introducing glycoprotein IIb/IIIa inhibitor therapy to air medical practice

Introduction: In patients with myocardial infarction, platelet aggregation inhibition with glycoprotein IIb/IIIa antagonists helps restore and maintain coronary blood flow when administered alone, with fibrinolytics, or with angioplasty. This article evaluates whether an adequate number of patients transported by an air medical program could benefit from flight team administration of these agents and describes the implementation issues surrounding a treatment protocol. Methods: A retrospective chart review and a discussion of the program's implementation experience Results: Seven percent of the patients transported by the air medical program met clinical and electrocardiographic criteria for administration of glycoprotein IIb/IIIa inhibitors. The program identified systemic, budgetary, and logistical issues with protocol implementation that require ongoing consideration.

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.

Just when you thought you had nothing else to worry about—Medical director liability

Savvy lawyers are beginning to add health care program medical directors to their list of potential defendants. Air medical program directors also can be expected to join the list of defendants in litigation involving their units. The new interest in medical directors started in an effort to reach HMOs that were otherwise immune or add more defendants to overcome damage caps or inadequate primary defendant insurance. The same situations drive the increased interest in the medical directors for EMS systems and air medical programs.

The impact of fatigue in air medical and other types of operations: A review of fatigue facts and potential countermeasures

Because of its effects on productivity and safety, fatigue is receiving increasing attention in a variety of settings, including aviation. Fatigue-related problems cost America an estimated $18 billion a year in terms of lost productivity, and fatigue-related drowsiness on the highways contributes to more than 1500 fatalities, 100,000 crashes, and 76,000 injuries annually. Furthermore, evidence is mounting that pilot and aircrew fatigue has been a causative factor in several aviation mishaps. Although substantial research has been conducted on the nature of fatigue and the effectiveness of various countermeasures, much of the relevant information may not be reaching those who need it most. The importance of obtaining adequate daily sleep and the efficacy of proper work/rest schedules, strategic napping, rest breaks, circadian-entrainment interventions, and other techniques should be emphasized in air medical training programs along with the more standard courses aimed at maintaining crew skills and improving flight safety. Once the facts are known, the aircrew's ability to control fatigue will enhance the productivity and safety of air ambulance operations.