Cost-effectiveness analysis of potential improvements to emergency medical services for victims of out-of-hospital cardiac arrest

STUDY OBJECTIVE: To measure the incremental cost-effectiveness of various improvements to emergency medical services (EMS) systems aimed at increasing survival after out-of-hospital cardiac arrest. METHODS: We performed cost-effectiveness analysis based on (1) metaanalysis of effectiveness of the various EMS systems, (2) costing of each component of EMS systems, (3) modeling of the relationship between the proportion of cardiac arrest victims who receive CPR and the proportion of individuals trained, (4) modeling of the relationship between response time interval and the characteristics of the EMS system, (5) measurement of quality of life, and (6) decision analysis to combine the results of the first five components. RESULTS: The incremental cost-effectiveness ratio for a 48-second improvement in mean response time in a one-tier EMS system yielded by the addition of more EMS providers was $368,000 per quality-adjusted life year (QALY). For improved response time in a two-tier EMS system by the addition of more basic life support (BLS)/BLS-defibrillator (BLS-D) providers to the first tier, the ratio was $53,000 per QALY with pump vehicles or $159,000 per QALY with ambulances. Change from a one-tier EMS to a two-tier EMS system by the addition of initial BLS/BLS-D providers in pump vehicles as the first tier was associated with a cost per QALY of $40,000. Change from one-tier EMS to two-tier EMS by the addition of initial BLS/BLS-D providers in ambulances as the first tier was associated with a cost per QALY of $94,000. CONCLUSION: The most attractive options in terms of incremental cost-effectiveness were improved response time in a two-tier EMS system or change from a one-tier to a two-tier EMS system. Future research should be directed toward identification of the costs of instituting the first tier of a two-tier EMS system and identification of cost-effective methods of improving response time.     

Telephone triage of cardiac emergency calls by dispatchers: a prospective study of 1386 emergency calls

OBJECTIVES: To evaluate the handling of potential cardiac emergency calls by dispatchers, to determine their final diagnosis and urgency, and to determine the value of the main complaint in predicting urgency and the ability of the dispatchers to recognise non-urgent conditions. DESIGN: Prospective data collection and recording of main complaint of emergency calls placed via the 06-11 alarm telephone number with follow up to hospital when the patients were transported and the general practitioner when they were not. SETTING: Dispatch centres of the emergency medical services in Amsterdam (urban area) and Enschede (rural area). PATIENTS: 1386 consecutive adult subjects of emergency calls placed by citizens about chest problems or unconsciousness not caused by injury. MAIN OUTCOME MEASURES: Frequency of characteristics of the calls, outcome in diagnosis, and assessment of urgency. RESULTS: 69 (5%) patients were dead when the ambulance arrived. Diagnosis was established in 1071 patients (77%). The disorders most often reported were cardiac, with acute ischaemia in 15% of all subjects. In 28% of cases and for each presenting complaint no organic explanation was found. Overall 39% of all emergency calls were urgent; the urgency rate was lowest for calls for people with abdominal discomfort. Dispatchers correctly identified 90% of the non-urgent calls, but 55% of the calls that they identified as urgent proved to be non-urgent. CONCLUSION: Currently, direct dialling for an ambulance without the intervention of a general practitioner imposes a high work load on emergency systems and hospitals because triage by dispatchers is not sufficiently accurate. It may be possible to increase the accuracy of triage by developing and testing decision algorithms.     

New vision for the role of emergency medical services

Genital human papillomavirus (HPV) infection is the major causal factor of cervical intraepithelial neoplasia (CIN). The potential role of nutrition as an additional, independent risk factor for CIN has not been appropriately addressed in the context of HPV. This case-control study evaluated the etiologic role of HPV in terms of viral type and load and examined the association between CIN and plasma levels of micronutrients adjusting for HPV. Cases (n = 378) with histo-pathologically confirmed CIN and controls (n = 366) with no history of abnormal Pap smears were recruited from colposcopy and gynecology clinics, respectively. Risk of CIN was significantly increased among women who were infected with multiple HPV types (odds ratio [OR] = 21.06), a high viral load (OR = 13.08) and HPV 16 (OR = 62.49). After adjusting for HPV positivity and demographic factors, there was an inverse correlation between plasma alpha-tocopherol and risk of CIN (OR = 0.15). Plasma ascorbic acid was protective at a high level of > or = 0.803 mg/dl (OR = 0.46). CIN was not associated with plasma retinol and beta-carotene levels. The effect of genital HPV infection on CIN development is highly influenced by oncogenic viral type and high viral load. Vitamins C and E may play an independent protective role in development of CIN that needs to be confirmed in prospective studies.     

Organizational problems in emergency medical care and reorganization of emergency services in hospitals

Entropic properties of the neural signal space, the neurodynamic basis of Weber's and Steven's law. Acta Physiol. Pol., 1977, 28 (2): 113--116. Taking into account the number of neural units, number of their efferent synapses and the average impulse frequency as well as the notion of neural momentum the dependence of neural entropy on neural tonus was examined. Based on the above model the neurodynamic basis of the Weber's and Steven's law was considered.     

Changes in medical problems and use of medical services following psychological intervention.

Important life changes and significant psychological stress occur before, during, and after episodes of physical illness in the lives of many individuals. Significant life-adjustment or developmental difficulties have been shown to be associated with high use of medical services. This article discusses the reduction in medical problems and use of medical facilities with referral for psychological services. On the assumption that psychologists can contribute significantly to reduction in patients' psychological stress levels and associated physical complaints, a new self-image for many psychologists could be that of health care professional. Furthermore, this self-image and role could be implemented by having psychologists contribute to the treatment of patients in a continuous manner, starting with the initial patient visit to a health care facility. (44 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of first-responder defibrillation in an urban emergency medical services system

OBJECTIVE: To evaluate the impact of adding first-responder defibrillation by fire-fighters to an existing advanced life-support emergency medical services system. DESIGN: Nonrandomized, controlled clinical trial with periodic crossover. SETTING: Memphis, Tenn, a city of 610,337 people, which is served by a fire department-based emergency medical services system. All city ambulances provide advanced life support. PATIENTS: Adult victims of out-of-hospital cardiac arrest due to heart disease. INTERVENTION: Twenty of 40 participating engine companies were equipped with an automated external defibrillator and ordered to apply it immediately in all cases of cardiac arrest. The other 20 companies were ordered to start cardiopulmonary resuscitation (CPR) immediately and wait for paramedics to arrive. Every 75 days, group roles were reversed. Care otherwise proceeded according to 1986 American Heart Association guidelines. MAIN OUTCOME MEASURES: Return of spontaneous circulation in the field, survival to hospital admission, survival to hospital discharge, and neurological status at discharge. RESULTS: During the 39-month study interval, 879 patients were treated by a project engine company. Four hundred thirty-one (49%) of these were found in ventricular fibrillation. Bystander CPR was started in only 12% of cases. Overall, firefighters reached the scene a mean of 2.5 minutes faster than simultaneously dispatched paramedics. Although our automated external defibrillators proved to be reliable and efficacious for terminating ventricular fibrillation and pulseless ventricular tachycardia, patients treated by an automated external defibrillator-equipped engine company were no more likely than CPR-treated controls to be resuscitated (32% vs 34%, respectively), to survive to hospital admission (31% vs 29%), or to survive to hospital discharge (14% vs 10%). Neurological outcomes were also similar in the two treatment groups. CONCLUSIONS: In a fast-response, urban emergency medical services system served by paramedics, the impact of adding first-responder defibrillation appears to be small. Early defibrillation alone cannot overcome low community rates of bystander CPR. Careful attention to every link in the "chain of survival" is needed to achieve optimal rates of survival after cardiac arrest.     

The role of emergency medical services in primary injury prevention. East Carolina Injury Prevention Program

Recent studies have shown a high frequency of genetic hemochromatosis in the Caucasian population. In addition, the well known organ involvement of genetic hemochromatosis was evident; more than 50% of patients develop a typical arthropathy which may result in severe physical disability. Among approximately 5000 patients referred to the rheumatology outpatient clinics of Bad Nauheim and Frankfurt with different rheumatologic diagnoses, 11 patients with typical signs of hemochromatotic arthropathy were identified. In none of those cases had the diagnosis "genetic hemochromatosis" been previously established. These patients had been treated for rheumatoid arthritis and other rheumatologic disorders over several years. All showed severe organ dysfunction due to iron overload, resulting in a reduced life expectancy. This investigation shows that knowledge of the typical signs of hemochromatotic arthropathy could lead to an earlier diagnosis of genetic hemochromatosis which is necessary to prevent the complications of iron overload in those patients.     

Implementation of legislative requirements for emergency medical services in prepaid group practice organizations

This study was based on the concept that intracellular accumulation of calcium plays a role in mediating ischemic myocardial injury and that inhibition of entry of calcium into cells may have a salutary effect on the ischemic heart. Nifedipine, a potent vasodilator and inhibitor of transmembrane calcium flux, was infused into the aortic root of 6 dogs (5 microgram/kg/hr) during 2 hours of myocardial ischemia while on cardiopulmonary bypass. Seven control animals received normal saline at the same flow rate and temperature (20 degrees C). The results showed that none of the 7 control animals were able to maintain adequate aortic pressure or cardiac output after 30 to 60 minutes of normothermic reperfusion. All had marked left ventricular failure and were unresponsive to large doses of inotropic agents. In contrast, the 6 dogs treated with nifedipine were weaned from bypass either without difficulty or requiring small doses of calcium chloride and norepinephrine. Light microscopy demonstrated more marked ischemic damage in the control group than in the group of drug-treated dogs. We conclude that the concept of inhibition of transmembrane calcium flux offers a new and potent method for myocardial preservation during ischemia.     

A GP looks abroad: emergency medical services in the Federal Republic of Germany

1. The methylester derivative of DNP-amino acid was examined by gas-chromatography and amino acid shown in fig. 1 was detected. 2. The gaschromatography was more sensitive than the ion-exchange chromatography, but detectable peaks were few, and it must be further studied. 3. The measurements of five amino acids in food were almost coincident with those obtained by the ion-exchange method in literatures.     

Gender-specific factors in the utilization of medical services during adolescence

Properties of receptors for glutamate, consisting of kainate, alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), and N-methyl-D-aspartate (NMDA), and gamma-aminobutyric acid (GABA) in the rat trigeminal ganglion (TG) neurons were studied by means of the whole-cell patch-clamp technique. 1. All TG neurons (diameter 20 approximately 40 microns) responded to GABA, but none of them responded to AMPA, NMDA, and glycine. TG neurons responding to kainate were smaller than 25 microns and desensitized by prolonged agonist exposure. 2. On the basis of the dose-response curves, EC50 and Hill coefficient were found to be 13. 7 microM and 1.2 for kainate, while those for GABA were 28.6 microM and 2.0, respectively. 3. Most kainate receptors in the TG neurons showed linear current-voltage (I-V) relations, though some showed inward rectification. The "Instantaneous" I-V relationship for GABA was linear, where as the "steady-state" I-V relationship produced by ramp changes in potential showed outward rectification in some neurons. 4. The number of TG neurons responding to kainate increased until the 8th postnatal day, while all the recorded neurons responded to GABA in postnatal days. The results indicated that there are kainate and GABAA receptors in the TG neurons and suggested that they are composed of various subunits.     

Invasive aspergillosis of the paranasal sinuses: a medical emergency

A rare case of invasive aspergillosis of the paranasal sinuses in a previously healthy individual is presented. The disease caused severe complications and proved fatal. Classification, aetiology and presentation of sinus aspergillosis are discussed. Early diagnosis and management is stressed to avoid the high incidence of morbidity and mortality.