Why IFR?

Introduction: Air medical services can use aircraft equipped to fly under visual flight rules (VFR) or instrument flight rules (IFR). IFR allows the pilot to fly safely into lower weather minimums, potentially increasing the number of EMS flights that can be completed. We examined the advantages and disadvantages of both methods of helicopter flight, the potential service gain with IFR capability, and the financial feasibility of using IFR in an urban air medical program.Methods: Retrospective data were collected on the number of missed flights for Vanderbilt LifeFlight during a 6-year period. Focusing on 2 recent years, we examined the number of flights missed because of weather. Data were prospectively obtained on missed flights that could have been completed with IFR from April 1997 to March 1998. Financial estimates were calculated to determine the revenue potential of an IFR program.Results: An average of 24% of flights were missed from 1991 to 1997. In 1996–97, primary reasons for missed flights included poor visibility and low clouds, conditions in which IFR capable helicopters could fly. Prospective data from 1997–98 indicated an average of 6.7 missed flights per month potentially could have been completed with IFR. Analysis of expenses and revenue suggest that converting a ship from VFR to IFR, which involves both equipment purchases and pilot training, is economically feasible given the potential revenue gained by the number of flights completed during marginal weather conditions.Conclusion: Implementing an IFR program increases the safety margin and allows better EMS service to the community.     

Analysis of patients discharged from receiving hospitals within 24 hours of air medical transport

Introduction: Use review has become increasingly important in the current atmosphere of cost justification for air medical transport. One criterion for use review is patient discharge from receiving hospitals within 24 hours of transport. The objective of this study was to determine the frequency and characteristics of patients discharged within 24 hours of air transport; the goal was to identify particular patient types likely to be discharged soon after air transport.Methods: Flight records from November 1994 to September 1995 were reviewed. Follow-up identified patients who were discharged within 24 hours of air medical transport; these were designated the “24-hour group.” Other patients were designated the “overall group.” Comparisons between groups were made using the t test, Wilcoxon rank sum, and chi-square analysis (α = 0.05) for the following factors: age, vital signs, Glasgow coma score, percentage of intubated patients, and percentage of trauma and scene transports.Results: Of the 945 flights analyzed, 42 (4.4%) transported patients who were discharged within 24 hours of air transport. Patients in the 24-hour group were younger, less likely to be intubated, and more likely to be scene-trauma transports compared with the overall group.Conclusion: This study demonstrates that air medical transports meet currently accepted criteria for helicopter transport. This study suggests that inappropriate air medical transport is rare, even in patients discharged from receiving hospitals within 24 hours of air transport.     

The impact of multiple patient transport on patient care in helicopter emergency medical services

INTRODUCTION: Many helicopter emergency medical services can transport either one (singles) or two (doubles) patients. The purpose of this study was to investigate whether the additional patient in the doubles flight had an adverse impact on patient care because of the deceased provider-to-patient ratio. SETTING: Patients were flown by a Level 1 trauma center-based helicopter emergency medical service staffed by a nurse and paramedic. METHOD. A retrospective record and trauma registry review comparing 124 randomly selected scene trauma singles frequency-matched to 100 doubles (1/89 through 6/92) was performed. Data collected included patient demographics, Injury Severity Score, Glasgow Coma Scale, Revised Trauma Score, mechanism of injury, scene time, and ground ALS and helicopter emergency medical services procedures performed. RESULTS: Doubles accounted for 6.5% of all on-scene helicopter emergency medical service trauma patient transports. Paired comparison of Glasgow Coma Scale, Revised Trauma Score, and Injury Severity Score revealed that only one of the doubles patients had a field Glasgow Coma Scale as low, or a Injury Severity Score as high as the average singles. Revised trauma scores were equivalent. Although more procedures were performed during doubles missions, no procedures were performed in most singles missions (58%) and a substantial minority of doubles missions (41%). No differences were found between the groups in change in Glasgow Coma Scale during flight. CONCLUSION: Only of the two patients during doubles missions was as severely injured as the average patient in a singles transport. The decreased ratio of helicopter emergency medical service crew to patients in doubles missions does not jeopardize patient care because few procedures were performed during either singles or doubles missions.     

Is air medical scene response for illness appropriate?

The purpose of this study was to determine the appropriateness of air medical scene response for illness. The study consisted of a retrospective chart review of a two-helicopter urban air medical transport program with a transport volume of 1,700 flights annually. During the study period, January 1988 through March 1990, 68 patients were transported by helicopter from scene of illness to a tertiary care facility. In cases in which patients could be managed appropriately locally, air transport was deemed unnecessary. Of the 68 patients with illness, 40 were males and 28 were females; the average age was 39.2 years (from a range of 0 to 93). The average transport time was 46.3 minutes. Dispatch diagnoses were cardiac arrest (20), seizure (14), myocardial infarction (8), overdose (6), stroke (5), labor (4), respiratory distress (3) and miscellaneous (8). The discharge (final) diagnosis was different from dispatch diagnoses in 10 patients (14.7%). Fifty-four patients (79.4%) required no tertiary care, and 30 of them were discharged from the emergency department or were pronounced dead there or at the scene. The results of the study indicate air medical response to scene of illness did not appear justified in this study. Transport should be local, by ground, with subsequent tertiary care being arranged as needed. Further prospective study is warranted.     

Effets de la gymnastique d'entretien sur la consommation de médicaments psychotropes par les seniors

Objectives. – To evaluate the effect of a regular physical activity on the use of hypnotics, anxiolytics and antidepressants among elderly.Main facts. – Survey by self-administered questionnaires in 12 months of interval. The response rate was 55% (1709 females and 192 males, mean age 68.4 ± 5.6 years). Physical activity: they practiced soft gymnastics for 11.3 years on average, at a rate of 1.7 ± 1.0 sessions (2.0 ± 1.4 hours) per week, but 152 subjects had begun this activity. Psychotropic drugs: during the last 30 days, 13.9% of our respondents said that they have taken hypnotics, 5.6% had used anxiolytics and 4.7% had used antidepressants. The average percentage of hypnotics users is higher at those which has just begun (23.8% vs 13.2%, P < 0,05) and it drops after one or two years of regular practice (18.2% after one-two years, 13.1% after three-nine years, 11.0% after ten years, P < 0.05). Of the elderly who began the activity, 24.3% said that they have used hypnotics or anxiolytics during the past 30 days. One year later, they were only 5.9% (P < 0.05). The effects are less convincing for the antidepressants.Conclusions. – Regular practice of soft gymnastics could decrease the use of certain psychotropic drugs among elderly.     

Composition corporelle et densité minérale osseuse chez des garçons et des filles prépubères : effet de 13 semaines d'entraînement en endurance

Aim. – To investigate the effect of an endurance training program, on the bone mineral density and body composition of prepubertal boys and girls. The Regional Bone Mineral Density and Body.Materials and methods. – Composition were measured by dual energy X-ray absorptiometry (DXA, Hologic QDR 1000/W, Hologic, Waltham,MA) and maximal oxygen uptake by a continuous and progressive exercise test to exhaustion.Results. – A 13-week endurance training program is effective for increasing maximal oxygen uptake, but no sufficient to increase the Bone Mineral Density and to change the Body Composition in healthy prepubertal children.     

Effet d'une prise en charge pluridisciplinaire sur l'adiposité et la condition physique d'adolescent(e)s obèses

Aim. – To investigate the effects of physical activity and nutritional intake on obese adolescents body mass index (BMI) and physical condition.Methods. – Each month, adolescent BMI and physical condition were determined during 10 months.Results. – BMI was significantly decreased after 10 months in both sexes but did not differ between sexes. Physical condition of adolescents was significantly increased and gender difference appeared. The evolution of adolescent body weight, during the protocol, was not associated with the age of obesity appearance. Also, the number of obese parents did not influence the adolescents body weight decrease.Conclusion. – This study demonstrated that multidisciplinary weight-reducing program presents beneficial effects on health.     

Transcranial oximetry as a new monitoring method for HEMS

Introduction: Transcranial oximetry (TCO) is a new method to measure continuous changes in brain blood oxygen saturation (rSO₂) by using near-infrared spectroscopy (NIRS). To our knowledge, no studies about TCO in air medical transport have been published.Methods: Twenty healthy volunteers (HEMS medical crew) were investigated during flight missions without patients. We measured oxygen saturation (SpO₂), cardiac rate, and rSO₂ with an INVOS 4100 Cerebral Oximeter^® at sea level and at each 1000 feet until we reached a flight level of 5000 feet.Results: The oximeter did not produce any interference with medical or aeronautical equipment. Subjects' SpO₂ showed a slight decrease with altitude (P<0.010), but rSO₂ remained constant (P=0.28), with little delay in the physiological correction of SpO₂ and rSO₂ values.Conclusion: TCO may play an important role in the development of new monitoring methods for critical patients in air medical transport. Further studies with large sample sizes and patients are necessary to generalize findings.     

Le questionnaire de surentraînement de la Société française de médecine du sport : reproductibilité à court termeOvertraining questionnaire of the Société française de médecine du sport (French Society of Sport Medicine): short term reproducibility

Purpose. – To assess the short-term stability, over time, of a slightly modified version of the overtraining questionnaire proposed by the SFMS.Methods. – Three or 7-day test–retest of the questionnaire was completed in 30 high level athletes. In a first stage analysis, the score obtained during the first test was compared to and correlated with that obtained during the second one. Then, in a second stage analysis, the individual reproducibility of each item was assessed using a similitude index: a value of 100% meant that all the athletes gave an identical response for the two trials.Results. – Scores were not different between the two tests and intra-class correlation coefficients were r = 0.82. Overall reproducibility of the similitude index was quite good even if six items of 52 displayed a lower similitude index (around 80%).Conclusion. – The short-term reproducibility of the overtraining questionnaire is quite good. This result reinforces its reliability and warrants its use in a longitudinal follow-up framework aimed to detect precociously an overtraining syndrome.     

Intérêt du questionnaire de surentraînement de la Société française de médecine du sport lors d’un suivi de sportifsOvertraining questionnaire of Société française de médecine du sport for a continuous observation in a sport population

Aim. – Verify the sensibility of a standardised overtraining questionnaire during a weekly observation in a sport population.Methods and results. – The experiment was carried out in 12 athletes, 20–23 years old, students at the University in Licence STAPS, with a standardised overtraining questionnaire given every week during 8 weeks. Results were analysed individually and for the total population. Those showed that overtraining questionnaire could allow individualised training programs, and could provide some pertinent information on sleep quality and physical condition for each athlete. For the coach, the overtraining questionnaire permits to identify some fatigue state, consecutively to training variations. On the total population, the analysis of overtraining questionnaire showed some items more reliable than other.Conclusion. – This questionnaire was very interesting for coaches, allowing a good individualisation of the training program. Nevertheless, this questionnaire presents intricate statistical analysis when given at high frequency.     

Effet du déconditionnement suite à une chirurgie du genou sur l'aptitude aérobie

Introduction. – The object of this study consisted in analysing the changes in cardiorespiratory fitness of fourteen sportsmen having undergone a surgical operation following a lesion of the anterior cruciate ligament of the knee.Methods and results. – Two triangular and maximum tests starting from the upper limbs were carried out before and after the operation with 7 days of interval. The results showed that the operation followed by a few days of bed rest generates a fast and significant reduction in the maximum oxygen consumption (–7%, p < 0.05) and peak aerobic power (–8%, p < 0.05).Conclusion. – These results could encourage therapists to propose endurance training during rehabilitation protocols.     

Effects of utmost fatigue on undisturbed upright stance control

Aim. – To assess the effects of utmost fatigue on balance control in upright quiet stance.Method. – Eleven subjects performed a postural task before and after completing a long distance triathlon. The centre of pressure (CP) displacements was recorded through a force platform and decomposed from a biomechanical relationship into two elementary motions: the horizontal motions of the centre of gravity (CG), and the difference CP – CG. These motions were then studied through three different analysis processes.Results. – A large increase of the oscillations is seen for both elementary motions. Interestingly, CG motions are particularly sensitive to fatigue and present an 83% increase for mean amplitudes while only a 44% increase is seen for CP – CG motions. Moreover, a large increase is observed in the mean time interval and the mean distance covered before a corrective process occurs. Finally, impairment of the muscular means brought into play and the decrease in ability to minimise body sways following utmost fatigue are discussed.Conclusion. – Postural instability following exhausting exercise is due both to muscular activity perturbation and to an impairment of the system’s capacity to control the position of the CG. This last point seems of a particular interest since it highlights a possible limit of the system to handle the controlled.     

A rural ambulance helicopter system in northern Sweden

INTRODUCTION: In Sweden, several ambulance helicopter programs have been used during the past 3 decades. This article describes one of these programs. SETTING: The catchment area of the helicopter system under study was a typical rural setting with a population density of less than 5 people per square kilometer. METHODS: We describe in detail, with special reference to medical aspects, the activities of an helicopter ambulance program in 1997. RESULTS: A total of 288 missions, including 328 patients (204 men), were analyzed. Trauma cases (29%) and patients with cardiovascular (24%) and neurologic problems (13%) dominated the missions. One-sixth of the cases occurred at night. The median response time was 12 minutes, and the median on-scene time was 28 minutes. The medical interventions performed included intubations; central venous catheter, arterial needle, and duodenal tube insertions; and medication administered intravenously, orally, and intrabronchially. CONCLUSION: We detected a higher rate of trauma cases than in previously published investigations, probably related to the outdoor activities of the area. We believe that the rapid institution of thrombolytic treatment in suspected acute myocardial infarction and a more rapid and flexible transport of trauma cases in a rural area are important. We estimate that, in most cases, the helicopter service could provide a quicker transport than a ground ambulance; however, for short distance transports, ground ambulance is faster than helicopter ambulance.     

Somatotypes et débit cardiaque chez les handballeurs d'élite

Objective – The aim of this research is to study the relationship between the cardiac output (CO) and the somatotype in elites handball players.Facts – The CO of endomorphs (ENDO) is significantly higher than mesomorphs (MESO) at rest (P < 0,01) and at 70% (P < 0,01). The QO presents a significant correlation with the fat free mass (FFM) in all the population of study (P < 0,001).Conclusion. – This study shows that the FFM could be considered as a determining factor of the variation of the CO between the ENDO and the MESO.     

Applying ‘Evidence-Based Medicine’ Theory to Interventional Radiology.Part 2: A Spreadsheet for Swift Assessment of Procedural Benefit and Harm

AIM: To design a spreadsheet program to analyse interventional radiology (IR) data rapidly produced in local research or reported in the literature using ‘evidence-based medicine’ (EBM) parameters of treatment benefit and harm.MATERIALS AND METHODS: Microsoft Excel^TMwas used. The spreadsheet consists of three worksheets. The first shows the ‘Levels of Evidence and Grades of Recommendations’ that can be assigned to therapeutic studies as defined by the Oxford Centre for EBM. The second and third worksheets facilitate the EBM assessment of therapeutic benefit and harm. Validity criteria are described. These include the assessment of the adequacy of sample size in the detection of possible procedural complications. A contingency (2 × 2) table for raw data on comparative outcomes in treated patients and controls has been incorporated. Formulae for EBM calculations are related to these numerators and denominators in the spreadsheet. The parameters calculated are benefit — relative risk reduction, absolute risk reduction, number needed to treat (NNT). Harm — relative risk, relative odds, number needed to harm (NNH). Ninety-five per cent confidence intervals are calculated for all these indices. The results change automatically when the data in the therapeutic outcome cells are changed. A final section allows the user to correct the NNT or NNH in their application to individual patients.RESULTS: This spreadsheet can be used on desktop and palmtop computers. The MS Excel^TMversion can be downloaded via the Internet from the URL ftp://radiography.com/pub/TxHarm00.xls.CONCLUSION: A spreadsheet is useful for the rapid analysis of the clinical benefit and harm from IR procedures.MacEneaney, P. M. & Malone, D. E. Clinical Radiology55 938–945.     

Augmentation de la fréquence d’apparition de l’hypoxémie induite par l’exercice chez des rameurs de haut-niveau

Objectifs. – Évaluer la fréquence d’apparition de l’hypoxémie induite par l’exercice (HIE) chez un groupe de rameurs de haut-niveau.Méthodes. – Sept rameurs de haut-niveau ont participé à l’étude (19,14 ± 1,3 ans). Les sujets ont effectué une épreuve d’effort à charge croissante sur un rameur ergométrique lors de laquelle les échanges gazeux et la saturation de l’hémoglobine en oxygène (SpO₂) ont été mesurés.Résultats. – Les sujets avaient une VO₂max de 61,68 ± 1,65 ml/min par kilogramme. Tous ont présenté une HIE avec des chutes de SpO₂ comprises entre 5 et 11 %. Cette chute était significative dès 70 % VO₂max. Le volume d’entraînement réduit des athlètes testés par rapport aux autres athlètes endurants semble indiquer que le phénomène est indépendant du volume d’entraînement.Conclusion. – Cette étude a permis de mettre en évidence que 100 % des rameurs de haut-niveau présentaient une HIE. La limitation ventilatoire et l’importante masse musculaire mise en jeu spécifiques à l’aviron seraient les hypothèses explicatives.Aim. – To access the frequency of exercise-induced hypoxemia (EIH) in elite oarsmen.Method. – Seven elite oarsmen participated (19.14 ± 1.3 year) in this study. Subjects performed an incremental exercise testing on a rowing ergometer. Gas exchanges and pulse oxymetric saturation in oxygen (SpO₂) were measured during exercise.Results. – Subjects exhibited a mean of VO₂max of 61.68 ± 1.65 ml min^–1 kg^–1. All rowers showed an EIH with a SpO₂ ranging between 5% and 11%. This SpO₂ fall was significant from 70% VO₂max. The reduced training volume of our athletes compared with others endurance trained athletes seems indicate that phenomenon is not dependent of training volume.Conclusion. – This study showed that 100% of elite oarsmen exhibit EIH. Mechanical limitation in ventilation and great muscle mass involved in rowing could be the explicative hypothesis.     

Effets de l'entraînement sur les potentiels aérobie et anaérobie de jeunes nageurs. Exercice réalisé avec les brasEffect of training on aerobic and anaerobic capacity in young swimmers. Exercise performed with arms

Aims – Investigate the influence of exercise training on the aerobic and anaerobic capacities of young swimmers.Methods – Ten male swimmers aged 15.2 ± 3.8 years participated: five sprint specialists and five middle-distance specialists. Each subject performed, an arm ergocycle, two laboratory tests, a maximal incremental exercise test and a force–velocity test, once in February (T1) and then again in June (T2).Results – For all subjects combined (n=10), the results showed a significant increase in maximal anaerobic power (p < 0.01) between T1 and T2. Aerobic capacity did not change significantly between the two tests in either group.Conclusion – This study demonstrates the interest of evaluating aerobic and anaerobic capacity in young swimmers during arm exercise. The change in results over the 5-month period between the two tests indicates the importance of scheduling exercise tests during the course of athletic training programs.     

Le « syndrome des jambes lourdes » chez les athlètes surentraînés est-il le reflet de désordres hémorhéologiques ?Is the feeling of heavy legs in overtrained athletes related to impaired hemorheology?

Introduction. – The aim of this work is to evaluate if the feeling of heavy legs in athletes is correlated with overtraining syndrome-related hemorheological disturbances.Results. – The subjects who quoted the item: “I have the feeling of heavy legs” had higher plasma viscosity and higher red cell aggregation parameters. The overtraining score was correlated positively with plasma viscosity, and aggregability parameters. The feeling of heavy legs was correlated with plasma viscosity and aggregability.Conclusion. – These findings suggest that the feeling of heavy legs in overtrained athletes is related to overtraining syndrome-related hemorheologic disturbances, namely mild plasma hyperviscosity and mild erythrocyte hyperaggregability.     

Blood usage in rotor-wing transport

INTRODUCTION: Blood transfusion for hemorrhagic shock is standard therapy. The purpose of this study was to document the development of protocols for administering red blood cells and review the experience with inflight blood transfusions. SETTING: This study was conducted at a hospital-based rotor-wing (RW) program whose service area is a large rural area in southeastern Minnesota. A BK 117 with a flight nurse/flight nurse configuration was used. METHODS: The RW registry was accessed during a 3-year period (August 1993 to July 1996), and 2131 records were reviewed to retrospectively analyze blood use during transport. Blood bank records and protocols also were reviewed. RESULTS: This helicopter program maintains a refrigerator with 4 units of O-negative blood that is kept in the hangar and serviced by the blood bank. Blood was taken on all appropriate transports (91% interfacility, 9% scene), and 94 of 2131 patients (4%) were transfused. Criteria for blood transfusion included Hgb < 10, persistent hypotension after resuscitation, and clinical signs of shock. Medical conditions consisted of trauma (48% of patients), gastrointestinal (GI) bleed (25%), abdominal aortic aneurysm (AAA) (17%), and other (10%). The mean Hgb before and after transport was 8.9 and 10.2, respectively; 38% of the patients received an average of 3 units before transport. Overall, 2 units red blood cells were given in flight and another 12 units during hospitalization. No complications occurred with blood transfusions. CONCLUSIONS: Selected RW patients will benefit from in-flight blood transfusions. Proximity of blood storage to the helicopter is mandatory to avoid delays in transport. A close working relationship with blood bank personnel ensures ready availability of current O-negative blood.