Cardiac arrest: comparison of paramedic and conventional ambulance services.

A prospective study conducted in the Greater Vancouver area compared survival rates in prehospital cardiac arrest managed by an advanced life support (paramedic) service with those in cardiac arrest managed by conventional ambulance service. Management by the paramedic service was associated with higher survival rates for patients found in cardiac arrest but not for patients who suffered the arrest while the ambulance was present. Cardiopulmonary resuscitation by bystanders was associated with a significant increase in survival rates when combined with paramedic services but not when only basic life support services were available.     

The Epidemiology and Prevention of Traffic Accidents Involving Child Pedestrians

A study of 713 motor vehicle accidents involving 749 children in the city of Vancouver is reported. A control group of 110 children who did not have accidents was included in the concurrent study. Factors investigated were the driver, the vehicle, the weather, the time of day, the day of week, the month, the width of roadway, the location of the accident, the child''s age, sex, personality, school record, and family background, the type of injury, and the ambulance and hospital service received. Boys were more commonly involved than girls, and most accidents occurred in the 3 to 7 year age group. Head injuries prevailed in the younger age groups and decreased steadily with the age of the child. Specific epidemic areas in the city were identified and selective enforcement was suggested as a possible countermeasure. Hospital records seldom provided a detailed history of the events leading up to the accident. In order to apply the preventive techniques of education and enforcement it was suggested that in each pedestrian traffic accident the driver should be required to accompany the victim to the site of medical care.     

General practitioner attendance at emergencies notified to ambulance control.

For two years doctors from a small village went to the scene of emergency calls received by ambulance control. On 80% of the occasions when the doctor was called at the same time as the ambulance was dispatched the doctor arrived before the ambulance. There were 24 incidents, 16 of which were road traffic accidents. In two cases the doctor established a clear airway in an unconscious patient before the ambulance arrived. Two patients were trapped in their vehicles and were given parenteral analgesics. Four patients required intravenous fluids. The call out system provided first aid for patients before the ambulance arrived and medical assistance to the emergency services at serious accidents. Patients who did not require hospital attention could be examined and treated at the scene, making the ambulance available for other duties and reducing the number of patients taken to the hospital accident and emergency department.     

Resuscitation of patients with cardiac arrest by ambulance staff with extended training in West Yorkshire.

OBJECTIVE--To investigate the results of resuscitation of patients with cardiac arrest by ambulance staff with extended training in West Yorkshire. DESIGN--Study of all such attempts at resuscitation over 32 months, based on the standard report form for each call made by the ambulance staff and the electrocardiogram that showed the initial rhythm in each patient. SETTING--Area covered by West Yorkshire ambulance service. SUBJECTS--1196 Patients with cardiac arrests attended by 29 ambulance staff with extended training. MAIN OUTCOME MEASURE--Result of resuscitation. RESULTS--The initial rhythm was asystole or electromechanical dissociation in 740 patients and ventricular fibrillation in 456 patients; overall 65 patients survived to be discharged from hospital. Sixty four of the 456 patients in whom ventricular fibrillation was the initial rhythm recorded, and 46 in whom ventricular fibrillation persisted after the ambulance staff arrived, survived. Only one of the 740 patients who initially had asystole or electromechanical dissociation survived. Factors associated with a greater chance of ventricular fibrillation occurring were: age less than 71, the arrest being witnessed by a bystander, resuscitation by a bystander, the arrest occurring in a public place, and a response time by the ambulance staff of less than six minutes. For patients found in ventricular fibrillation a shorter response time was associated with improved survival but resuscitation by a bystander was not. Additional skills learnt during extended training were used for 51 of the 65 patients who survived. CONCLUSIONS--Ambulance staff with extended training can save the lives of patients with cardiac arrest due to fibrillation, though asystole and electromechanical dissociation have a poor prognosis and should perhaps receive little attention during extended training.     

An Observational Study of Patient Characteristics Associated with the Mode of Admission to Acute Stroke Services in North East,England

Objective

Effective provision of urgent stroke care relies upon admission to hospital by emergency ambulance and may involve pre-hospital redirection. The proportion and characteristics of patients who do not arrive by emergency ambulance and their impact on service efficiency is unclear. To assist in the planning of regional stroke services we examined the volume, characteristics and prognosis of patients according to the mode of presentation to local services.

Study design and setting

A prospective regional database of consecutive acute stroke admissions was conducted in North East, England between 01/09/10-30/09/11. Case ascertainment and transport mode were checked against hospital coding and ambulance dispatch databases.

Results

Twelve acute stroke units contributed data for a mean of 10.7 months. 2792/3131 (89%) patients received a diagnosis of stroke within 24 hours of admission: 2002 arrivals by emergency ambulance; 538 by private transport or non-emergency ambulance; 252 unknown mode. Emergency ambulance patients were older (76 vs 69 years), more likely to be from institutional care (10% vs 1%) and experiencing total anterior circulation symptoms (27% vs 6%). Thrombolysis treatment was commoner following emergency admission (11% vs 4%). However patients attending without emergency ambulance had lower inpatient mortality (2% vs 18%), a lower rate of institutionalisation (1% vs 6%) and less need for daily carers (7% vs 16%). 149/155 (96%) of highly dependent patients were admitted by emergency ambulance, but none received thrombolysis.

Conclusion

Presentations of new stroke without emergency ambulance involvement were not unusual but were associated with a better outcome due to younger age, milder neurological impairment and lower levels of pre-stroke dependency. Most patients with a high level of pre-stroke dependency arrived by emergency ambulance but did not receive thrombolysis. It is important to be aware of easily identifiable demographic groups that differ in their potential to gain from different service configurations.     

Follow-up of emergency ambulance calls in Nottingham: implications for coronary ambulance servie.

Information about patients in ambulance service records has been linked to that in the patients'' hospital records in an attempt to make the most efficient use of a special ambulance service for patients suspected of having heart attacks. During one week 248 emergency (999) calls for an ambulance were made by the public in the city of Nottingham. The quality of information given to the ambulance centre was poor, and all four patients eventually found to have had a myocardial infarction were described as having collapsed. A further study of patients who were also described as having collapsed has led to a system which allows an ambulance controller to send a "coronary ambulance" only in answer to those emergency calls where there is a reasonable possibility that the patient has had a heart attack.     

At the roadside: assessment of activities of a general practitioner accident service.

Members of the Mid-Anglia General Practitioner Accident Service (MAGPAS) have completed an accident report form after attending each incident since the service was formed in 1972. In 1982 a new form was introduced, and this paper analyses the first 1000 forms that have been returned where a patient was examined at the roadside. During 1982, 1515 calls were received by MAGPAS, and in 97% of these a doctor was sent immediately: 55% of the calls were passed to the doctor within one minute of the receipt of the call in the MAGPAS control room and 81% within two minutes. The doctor arrived ahead of the ambulance in 40% of the callouts and 63 patients had an obstructed airway which was cleared by the doctor before the ambulance arrived. Of the 1816 patients seen, 142 required intravenous fluid replacement. This report suggests that in a rural area a well organised general practitioner accident service can play a vital part in the early management of seriously injured victims of road accidents.     

Importance of patient selection in evaluating a cardiac ambulance service.

All patients brought to hospital by a special cardiac ambulance were followed up and compared with patients carried by routine ambulances to assess the effectiveness of a cardiac ambulance service. The overall mortality of patients with heart attacks was 51% among those carried by an ordinary ambulance and 40% among those carried by the cardiac ambulance. The apparently low mortality in the latter group was balanced, however, by a high mortality (68%) among patients carried by ordinary ambulances when the cardiac ambulance was available but not used; these patients tended to have a short duration of symptoms and heart attacks away from home, and their ambulance was more often called by a member of the public than a general practitioner. It seems therefore that low-risk cases were inadvertently selected for transport by the cardiac ambulance; such unintentional selection makes it difficult to evaluate a cardiac ambulance service.     

Energy release and countermeasures for sand casting explosion accidents

Abstract

Sand casting explosion accidents seriously threaten employees' lives and the harmony and stability of society, such as casualties, equipment trouble and environmental pollution. The main purpose of this study was to determine the water requirement for sand casting explosion accidents, and then corresponding safety measures were proposed to prevent such accidents. First, the relationship between the water condition and temperature for such accidents was achieved based on an energy release equation in compressed gas expansion and the ideal gas state equation. The volume of vapor expanded rapidly as the temperature rises, which was also the immediate cause of sand casting expansion accidents. Also, the water requirement for the sand casting expansion accidents decreased rapidly as the temperature rises. Then, a bow-tie model was adopted for preventing the causes and consequences of sand casting explosion accidents. Three main causes were identified, namely molten metal meeting ponding, failure of cavity exhaust and low strength sand of sand mold, and 11 prevention safety measures were adopted to prevent the causes of such accidents. In addition, three consequences were identified, namely casualties, equipment trouble and environment pollution, and ten mitigation safety measures were adopted to mitigate the consequences of such accidents.     

Medical Aspects of Ambulance Design

Various observations have shown that the interior layout of many ambulances leaves much to be desired. The lighting levels are inadequate, heat loss could be prevented, vehicle identification and passage through traffic could be improved, and measurable differences exist between the ride characteristics of commercially available ambulances, a prototype purpose-built ambulance, and a private car. Moreover the condition of some patients may be affected by the motion of the vehicle either directly or indirectly. Even though they form a small percentage of the total number carried, they represent a very considerable financial risk. A personally conducted survey of ambulance chief officers showed a deep interest and involvement in the upgrading of the service with a general dissatisfaction with many of the vehicles currently available. Hence there is a market for the purpose-built ambulance, which would benefit the patient and the ambulanceman alike.The inadequacies of many vehicles currently in use as ambulances have been shown to work against the interests of the patient requiring life support treatment, and it is suggested that this warrants urgent attention and action. A more extensive research project involving medical observations on the supine sick and injured, attendant task performance, and instrumentation analysis of linear and angular vehicle motions should enable the harmful effects of ride motion to be identified.None of these investigations, however, will be of any value unless they are used in developing future ambulances. Such development must also parallel an increase in the awareness of the importance of ambulance design and its relation to the increased comfort and chance of survival of the patients carried.     

Sleepiness in a population of Italian shiftwork policemen

The aim of this study was to evaluate the effects of shiftwork on sleepiness, sleep disorders and sleep related accidents in a population of policemen. Data concerning age and physical characteristics, working conditions, sleep problems and accidents were collected by a questionnaire. Sleepiness was evaluated by the Epworth Sleepiness Scale (ESS) while the presence of sleep disorders was evaluated by a score (SD-score) drawn from indicators of insomnia, breathing disorders, periodic limb movements-restless leg syndrome and hypersomnia. The effects of age, gender, body mass index, working condition and seniority on ESS, SD-score and accidents were analysed by linear and logistic regression. Participants were 1280 policemen: 611 shiftworkers and 669 non-shiftworkers. The ESS scores were not higher in shiftworkers than in non-shiftworkers, but the SD-score was found to be significantly influenced by shiftwork condition and seniority. The occurrence of sleep-related accidents was found to have been significantly increased for shiftworkers and related to the presence of indicators of sleep disorders. The sleepiness could be underestimated or even overcome by the influence of stressing conditions. However our data should alert occupational health physicians for the diagnosis and prevention of possible lurking intrinsic sleep disorders likely to influence health problems and risk of accidents in shiftworkers.     

Pre-hospital Coronary Care Service

The Dublin cardiac ambulance service operates two specially-equipped ambulances from a private ambulance station; five metropolitan hospitals provide coronary care beds on a rota system. The service covers an area of 450 square miles (1,165 sq km) and a population of 800,000. The ambulances are staffed solely by trained ambulance personnel. During the first three years 1,973 patients were transported to hospital. Primary ventricular fibrillation was encountered in 20 patients and successfully treated in 17. No deaths occurred in the ambulance.Over 98% of the patients were transferred uneventfully to hospital, so a medical team from the hospital on duty was called on 30 occasions only. A feature of the Dublin service is the low cost of a standard ambulance call, at about £7·50.     

Simple training programme for ambulance personnel in the management of cardiac arrest in the community.

The extended training for ambulance personnel in Nottinghamshire includes a period of training in cardiac resuscitation by defibrillation, and defibrillators are now part of the standard equipment of vehicles used on the accident and emergency service. Comparison of recent results with previous attempts in the City of Nottingham to provide a service for out of hospital cardiac arrest has shown that an elementary training course and the provision of defibrillators on emergency vehicles enables the ambulance service to save the lives of a reasonable proportion of those who suffer sudden death in the community. The extended training programme as a whole has proved acceptable to ambulance personnel and we believe that this programme could be the basis for a more widespread introduction of post basic training.     

Immediate fatal outcome vs. fatal outcome within the first 48 hours following a severe traffic trauma--analysis of the possible effect of alcohol intoxication on the outcome

This paper is a retrospective analysis of data on 278 persons with fatal outcomes in traffic accidents in Osjecko--baranjska County, Croatia, during a five-year period. The observed sample of casualties was divided according to the time of fatal outcome into three groups: immediately deceased (139 or 50.0%), deceased within the first 48 hours (84 or 30.2%) and deceased after 48 hours (55 or 19.8%). A comparison of data was made for the first two groups of casualties, based on the level of alcohol intoxication, and an analysis of the possible influence of alcohol intoxication on an early outcome of severe trauma, which was defined as immediate fatal outcome and fatal outcome within the first 48 hours following the trauma. Casualties from the group of immediately deceased had a significantly higher average blood alcohol level than casualties from the group of persons deceased within the first 48 hours (shown through arithmetic mean of 0.81 g/kg vs. 0.33 g/kg, p =0.000). A binary logistic regression analysis showed that every increase in blood alcohol level by 1 g/kg also increased the odds of an immediate fatal outcome by 1.92 times (p=0.004). CONCLUSION: Beside increased risks of traffic accidents, the collected data showed that alcohol intoxication of accident participants also increases their chances of an immediate fatal outcome.     

Blast injury research models

Blast injuries are an increasing problem in both military and civilian practice. Primary blast injury to the lungs (blast lung) is found in a clinically significant proportion of casualties from explosions even in an open environment, and in a high proportion of severely injured casualties following explosions in confined spaces. Blast casualties also commonly suffer secondary and tertiary blast injuries resulting in significant blood loss. The presence of hypoxaemia owing to blast lung complicates the process of fluid resuscitation. Consequently, prolonged hypotensive resuscitation was found to be incompatible with survival after combined blast lung and haemorrhage. This article describes studies addressing new forward resuscitation strategies involving a hybrid blood pressure profile (initially hypotensive followed later by normotensive resuscitation) and the use of supplemental oxygen to increase survival and reduce physiological deterioration during prolonged resuscitation. Surprisingly, hypertonic saline dextran was found to be inferior to normal saline after combined blast injury and haemorrhage. New strategies have therefore been developed to address the needs of blast-injured casualties and are likely to be particularly useful under circumstances of enforced delayed evacuation to surgical care.     

Paramedics and technicians are equally successful at managing cardiac arrest outside hospital.

OBJECTIVE--To examine the effect on survival of treatment by ambulance paramedics and ambulance technicians after cardiac arrest outside hospital. DESIGN--Prospective study over two years from 1 April 1992 to 31 March 1994. SETTING--Accident and emergency department of university teaching hospital. SUBJECTS--502 consecutive adult patients with out of hospital cardiopulmonary arrest of cardiac origin. INTERVENTIONS--Treatment by ambulance technicians or paramedics both equipped with semiautomatic defibrillators. MAIN OUTCOME MEASURES--Rate of return of spontaneous circulation, hospital admission, and survival to hospital discharge. RESULTS--Rates of return of spontaneous circulation, hospital admission, and survival to hospital discharge were not significantly different for patients treated by paramedics as opposed to ambulance technicians. Paramedics spent significantly longer at the scene of the arrest than technicians (P < 0.0001). CONCLUSIONS--The response of ambulance paramedics to patients with cardiopulmonary arrest outside hospital does not provide improved outcome when compared with ambulance technicians using basic techniques and equipped with semi-automatic defibrillators.     

Randomised trial of a mobile coronary care unit for emergency calls.

A randomised trial was conducted to assess the value of sending a mobile coronary care unit (MCCU) to all emergency calls other than those for children or for patients injured in road-traffic accidents or brawls. Over 15 months 6223 calls for emergency ambulances were considered for the study, but a routine ambulance had to be dispatched on 2583 occasions because the MCCU was not available. A group of 1664 patients was randomly allocated to transport by the MCCU and 1676 patients to routine transport. In these groups the prehospital mortality among patients with heart attacks was 45% and 47%, and no patient survived resuscitation attempts long enough to leave hospital. During the same period general practitioners sent 190 patients with heart attacks to hospital in routine ambulances and none of them died during the interval between the call for the ambulance and arrival at hospital. Although it may be worth equipping all emergency ambulances with a defibrillator, MCCUs as at present envisaged will not appreciably affect mortality from heart attacks.     

Accidents involving off-road motor vehicles in a northern community.

The increasing number of accidents associated with off-road motor vehicles used for recreational purposes prompted this prospective study. During 1985 the records of victims of all motor vehicle accidents who were seen at the Hudson Bay Union Hospital, Hudson Bay, Sask., were studied; patients involved in on-road vehicle accidents were included for comparison. Emphasis was placed on age, vehicle type, mechanism of accident, injury severity and the use of safety features. Almost half of the victims of off-road vehicle accidents were under 16 years of age. The poor adherence to government legislation and manufacturer recommendations was evident in the number of people who did not wear helmets or use headlights.     

Mobile Coronary Care Provided by Ambulance Personnel

Mobile coronary care has been provided in Brighton by ambulance personnel without immediate help from physicians or nurses. No additional vehicles or staff were required. The capital cost of the experiment was therefore small and additional running costs were negligible. The results have been monitored by retrospective analysis of electrocardiograms recorded in the ambulance and stored on magnetic tape. In the first 12 months of operation to July 1972, 1,082 patients with suspected cardiac emergencies were carried in two vehicles. Subsequent analysis showed that 76% of these patients had acute symptoms from ischaemic heart disease or had circulatory arrest. Eighty-six per cent. of arrhythmias were diagnosed correctly by the ambulance attendants. Though only eight cases of primary ventricular fibrillation occurred during or shortly before transit all were successfully reversed, and five of these patients subsequently left hospital alive. Other benefits of the scheme have included an appreciable reduction in the median delay between onset of presenting symptoms in patients with acute myocardial ischaemia and their admission to hospital.