Tehran University Medical Journal

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Background: Aeromedical transport provides immediate advanced medical treatment for certain critically ill and injured patients, bringing about rapid treatment and decreasing the time of hospitalization. With the great expense of helicopter emergency medical services (HEMS), research and review of experience is conducted to determine areas in which the enforcement of standards will enable the effective and optimal use of HEMS.
Methods: We examined peer-reviewed published articles in French, English and Persian journals and medical texts to determine the best use of, and standards for, HEMS.
Results: We found that HEMS effectively improves health care in three categories of services: the rapid transportation of medical personnel/equipment to an accident and of patients to the hospital (primary response) meeting road ambulances at an intermediate point coming from a hospital or accident to transport patients to a hospital (secondary response) the planned urgent inter-hospital transfers of critically ill patients for specialized care (tertiary response). HEMS standards have been set for: the flight equipment and crew, the types of emergencies to which HEMS should respond, the optimal length of time for each part of the mission (call out time, response time, on-scene time, transport time, and total rescue time) and the affect on patient survival. Some other standards include: algorithms for patient screening, flight heights for different diseases and injuries, rooftop and parking garage helipad at hospital, approach of flight paths and the facility at the touchdown area. HEMS standard medical equipment includes those needed for telemedicine and basic and advanced life support. Standard drugs on board the HEMS vehicle depends on the type of the missions selected for HEMS. The area of medical crew members, as well as their fundamental and the continuing training, also has standards that must be met. The standard scoring system for severity of injury, and finally, the standard method for the annual calculation of the cost and benefit of using HEMS in a specified region have also been considered.
Conclusion: As trauma is a common reason for requesting HEMS in Iran, the decrease in "Golden Hour" response time for trauma patients is a priority. HEMS is expensive and enforcing standards also requires increased effort and expense. Nevertheless, both can reduce the morbidity, mortality and expense for longer hospital stays. Thus, the proper telemedicine and life support equipment and drugs, as well as algorithms for patient screening can improve HEMS efficacy. Furthermore, enforcing proper communication and record keeping regarding trauma severity for HEMS missions allows hospitals to predict the proper immediate treatment for incoming patients and its future need for HEMS services.

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Asthma is a chronic inflammatory disorder of the airways, associated with airway re-modeling and hyperresponsiveness. It is expressed that asthma influences about 300 million people around the world, which is estimated to increase to about 400 million by 2025. The prevalence rate is 15 to 20 percent in children and 5 to 10 percent in adults, while its trend is still increasing. Inflammation plays an important role in the patho-physiology of asthma, which involves an interaction of different types of the immune cells and mediators. It leads to a number of pathophysiology changes, including bron-chial inflammation, airway obstruction, and clinical episodes such as cough, wheeze and shortness of breath. Asthma is now greatly being introduced as a heterogeneous disorder and it is pointed out to the role of T cells, including Th1, Th2, Th17, and regu-latory T cells. Other immune cells, especially neutrophils, macrophages and dendritic cells, as well structural cells such as epithelial and airway smooth muscle cells also pro-duce disease-associated cytokines in asthma. Increased levels of these immune cells and cytokines have been recognized in clinical samples and mouse models of asthma. Different cytokines, including pro-inflammatory cytokines (such as TNFα, IL-1, and IL-6), T helper 2 cytokines (such as IL-4, IL-5, IL-9, IL-13), and growth factors (such as GM-CSF, PDGF) play a role in the pathogenesis of asthma. Indeed chemokines (such as MPC-1, RANTES , MIP-1) and the chemokine receptors (such as CCR3, CCR4, CCL11, CCL24, and CCL26) play an important role in the recruitment of circu-lating inflammatory cells into the airways in asthmatic patients and also is related with increased T helper 2 cytokines after inhaled allergens. Among new approaches, treat-ment of asthma with anti-cytokine drugs such as antibodies blocking IL-4, IL-5, IL-9 could reduce recruitment inflammatory cells into the airways and remodeling. The final perspective of asthma treatments would be to alter from the symptomatic treatments to disease modifying.