Basic Life Support Providers Research Articles

Effects of Early Defibrillation by Ambulance Personnel on Short- and Long-term Outcome of Cardiac Arrest Survival: The Munich Experiment

This study evaluates the feasibility of implementing early defibrillation of out-of-hospital cardiac arrest patients for basic life-support providers (EMT-D) in a two-tier emergency system in the city of Munich, Germany. Retrospective consecutive analysis of all EMT-D attempts during a 5-year initiation phase (1990 to 1994) and prospective follow-up of all cardiac arrest survivors discharged from hospital. A strictly defined inner-city and suburban area of 978 km2 and a residential population of 1,530,000 inhabitants with 22 ICUs in urban hospitals. One dispatching center to alert a two-tier emergency system with 56 EMT-D-staffed ambulances and physician-staffed mobile ICUs stationed at the nearest of nine hospitals. AH EMT-D cases were identified and data on patients were documented in a standardized manner from patients' records, including the resuscitation protocol in the hospitals to which the patients were referred. For those patients discharged from the hospital, a standardized telephone interview was undertaken with the physician in charge of the patient and with the patient/relative leading to an assessment of the patient's status according to the Glasgow-Pittsburgh cerebral performance categories. None. During the 5-year initiation phase of the EMT-D program in the two-tier emergency system in Munich, there were 243 resuscitation attempts by EMTs, using the semiautomated defibrillator; 125 patients died immediately on the scene. In 118 patients, spontaneous circulation was reestablished and these patients were admitted to an ICU in 1 of the 22 urban hospitals. Median call-response interval for the EMT-D was 5 min (interquartile range, 3 to 6) and was 10 min (interquartile range, 7 to 13) for the second tier (p < or = 0.0001). In 34 cases (28.8%), EMT-D staff had reestablished spontaneous circulation (ROSC) before the second tier arrived on the scene. Patients with ROSC on the arrival of the second tier were more frequently discharged alive from hospital than were patients without ROSC at that time (p < or = 0.0001). The hospital discharge rate of initially successful resuscitated patients presenting with out-of-hospital ventricular fibrillation was 38.1% (45/118). Overall success rate of all EMT-D attempts was 18.5% (45/243). After a mean follow-up time of 39 (range, 22 to 64) months, 29 (66%) patients were still living. Twenty-five (56.8%) were neurologically not disabled or mildly disabled (CPC 1/2); disability was moderate in 3 (6.8%) patients and was severe in 1 (2.3%) patient. One case was lost to follow-up. The present study demonstrates that the upgrading of basic life support providers with semiautomated defibrillators has a significant benefit for cardiac arrest victims outside the hospital in an urban environment.

The teaching of cardiopulmonary resuscitation in schools in Hampshire

In order to maximise the number of potential providers of cardiopulmonary resuscitation (CPR) in the community, it has been suggested that a programme of basic life support (BLS) training should be included within the school curriculum. Using a questionnaire sent to 275 schools in south east Hampshire (representing 71 716 pupils), we discovered that BLS was taught at only 26% of schools which replied. The age at which teaching commenced ranged from 7–16 years (mode=10 years). We estimated that almost 5000 children might currently be trained annually in these schools. Consequently, each year approximately 40% of children in south east Hampshire schools might be exposed to BLS training. On average, schools offering BLS tuition were larger, had more teaching staff and employed a higher proportion of staff who were themselves BLS providers. The majority of BLS teaching was undertaken by school staff (50.9% of schools) and members of the Red Cross, The St. John Ambulance Brigade or statutory ambulance service (30.9%). One school utilised members of the local fire brigade. Only one school offering BLS training to its pupils did not have a staff member trained in CPR.

Effectiveness of Emergency Medical Services for Victims of Out-of-Hospital Cardiac Arrest: A Metaanalysis

To determine the relative effectiveness of differences in response time interval, proportion of bystander CPR, and type and tier of emergency medical services (EMS) system on survival after out of hospital cardiac arrest. We performed a comprehensive literature search, excluding EMS systems other than those of interest (systems of interest were those comprising one tier with providers of basic life support [BLS] or advanced life support [ALS] and those comprising two tiers with providers of BLS or BLS-defibrillation followed by ALS), patient population of fewer than 100 cardiac arrests, studies in which we could not determine the total number of arrests of presumed cardiac origin, and studies lacking data on survival to hospital discharge. Metaanalysis using generalized linear model with dispersion estimation for random effects was then performed. Increased survival to hospital discharge was significantly associated with tier (P < .01), response time interval (P < .01), and bystander CPR (P = .04). A significant interaction was detected between response time interval and bystander CPR (P = .02). For the studies analyzed, survival was 5.2% in a one-tier EMS system or 10.5% in a two-tier EMS system. A 1-minute decrease in mean response time interval was associated with absolute increases in survival rates of .4% and .7% in a one-tier and two-tier EMS systems, respectively. Increased survival to hospital discharge may be associated with decreased response time interval and with the use of a two-tier EMS system as opposed to a one-tier system. The data available for this analysis were suboptimal. Policymakers need more methodologically rigorous research to have more reliable and valid estimates of the effectiveness of different EMS systems.

Does the level of prehospital care influence the outcome of patients with altered levels of consciousness?

Significant differences exist in the outcome of patients with altered level of consciousness (ALOC) cared for by advanced life support (ALS) compared with basic life support (BLS) prehospital providers. Patients transported by ambulance to a community teaching hospital during an 11-month period were studied retrospectively. Study patients were those considered not alert by prehospital personnel. Exclusion criteria included; trauma, intoxication, drowning, shock, and cardiac arrest. Data were abstracted from the ambulance reports and hospital records. Two hundred three patients with an ALOC were identified; 113 were transported by ALS providers (56%) and 90 (44%) by BLS providers. Prehospital levels of consciousness, according to the "alert, verbal, painful, unresponsive" scale (ALS vs BLS) were: "verbal" (40% vs 51%), "painful" (23% vs 23%), and "unresponsive" (37% vs 25%). The mean value for some time was 15 +/- 6 minutes for ALS versus 10 +/- 4 minutes for BLS (p < 0.001). On arrival in the emergency department, the LOC of 72 (64%) ALS patients and 58 (64%) BLS patients had improved to "alert." The level of consciousness in one ALS patient worsened. Fifty-two ALS (46%) and 38 (42%) BLS patients were admitted. Principal final diagnoses were seizure (27% ALS vs 38% BLS), hypoglycemia (23% ALS vs 23% BLS), and stroke (22% ALS vs 20% BLS). Remaining diagnoses each constituted less than 7% of total discharge diagnoses. No statistically significant differences in measures of outcome were noted between ALS or BLS patients. Diagnoses of seizure, stroke, and hypoglycemia were studied individually. No differences in admission rate, mortality rate, or disposition were identified. Hypoglycemic patients conveyed by ALS providers had significantly shorter emergency department treatment times than did those transported by BLS providers (160 +/- 62 minutes ALS vs 229 +/- 67 minutes BLS [p < 0.005]). Advanced life support levels of care of patients with an ALOC does not significantly change outcome compared with those receiving BLS care with the exception of shorter emergency department treatment times for hypoglycemic patients.

Pediatric prehospital care

The objective of this study was to analyze, by retrospective review, the pediatric population utilizing emergency medical services (EMS) throughout Kentucky, with particular emphasis on differences between urban and rural areas. The source of the data used was from all prehospital runs in children less than 17 years of age reported in Kentucky in a computerized database to the state EMS branch. There were no interventions. We found that pediatric calls were more frequent in adolescents than younger children. Trauma was more frequent in older children and in rural settings and accounted for nearly 50% of all calls. Motor vehicle accidents were the most frequent cause of traumatic injuries. Run times were prolonged in the rural setting, but this was a reflection of transport rather than scene times. The use of basic life support (BLS) and advanced life support (ALS) procedures was dependent on the patient's age and the level of care of the provider. ALS procedures were infrequently performed, especially in younger patients, although the performance of these procedures did not prolong scene times. We conclude that educational initiatives for pediatric care in the prehospital setting should include assessment and stabilization of children, including appropriate procedures, both for ALS and BLS providers. Prehospital data should be linked with police reports and emergency department data to provide means of assessing the impact of prehospital services on outcome in pediatric patients.

Out-of-hospital provider use of epinephrine for allergic reactions: pilot program.

To describe experience with an out-of-hospital provider program for the recognition and field management of allergic reactions by advanced life support (ALS) and basic life support (BLS) providers. Data sheets completed between June 1, 1988, and August 31, 1993, and records from receiving sites (physicians' offices or EDs) were reviewed for information regarding the presentation of the allergic reaction, the time course and treatment provided out of hospital, and the clinical outcome at the receiving health care facility. Thirty-seven data sheets were completed during the study period. Fourteen (38%) of the providers were BLS providers. The epinephrine was supplied from the emergency medical services (EMS) provider's personal kit in 35% of the cases, from an EMS vehicle in 57% of the cases, and by the patient in 8% of the cases. Availability of the kits allowed administration of epinephrine prior to the arrival of the first EMS vehicle in 41% of the instances and prior to physician on-line medical command in 65% of all the instances (predominantly by BLS providers). Overall, 77% of the patients experienced alleviation of their symptoms of respiratory difficulty, swelling, or rash after epinephrine administration, while 20% were unchanged and 3% worsened. All patients receiving epinephrine had an ED diagnosis of allergic reaction, and no adverse event was encountered on follow-up of the patients treated. Severe allergic reactions can be reliably identified and safely managed by out-of-hospital providers, including BLS providers. Providing personal anaphylactic treatment kits and increasing the pool of providers trained to manage allergic reactions (including BLS providers) can often decrease the time to treatment.

Effect of Out-of-Hospital Defibrillation by Basic Life Support Providers on Cardiac Arrest Mortality: A Metaanalysis

See related editorial, "Effectiveness of Basic Life Support Defibrillation." Study objective: Although some studies demonstrate otherwise, we hypothesized that metaanalysis would demonstrate a reduction in the relative risk of mortality when basic life support (BLS) providers can defibrillate out-of-hospital cardiac arrest patients. Design: Metaanalysis of studies meeting the following criteria: single-tier or two-tier emergency medical service (EMS) system, survival to hospital discharge for patients in ventricular fibrillation, and manual and/or automatic external defibrillators. The aerror rate was .05. Results: Seven trials qualified for metaanalysis. Across all trials, the risk of mortality for BLS care with defibrillation versus that without was .915 (P =.0003). Separate subset analyses of single-tier and two-tier EMS systems demonstrated similar results. Conclusion: BLS defibrillation can reduce the relative risk of death for out-of-hospital cardiac arrest victims in ventricular fibrillation. Weaknesses in individual study designs and regional clustering limit the strength of this metaanalysis and conclusion. [Auble TE, Menegazzi JJ, Paris PM: Effect of out-of-hospital defibrillation by basic life support providers on cardiac arrest mortality: A metaanalysis. Ann Emerg Med May 1995;25:642-648.]

Emergency medical training in the 82d Airborne Division. The Gulf War experience.

The 82d Airborne Division, as the Army's worldwide contingency division, places unique demands on its medical personnel. This was true particularly during Operations Desert Shield and Desert Storm in 1990-1991. An unprecedented emergency medical training program was carried out in preparation for the Gulf War. All levels of expertise were involved: non-medical Combat Lifesavers, medics, physician assistants, and physicians. Courses provided included Combat Lifesaver provider and refresher training, Basic Trauma Life Support (BTLS) provider and instructor training, Chemical Casualty courses, and a Combat Surgical Skills course. Approximately 736 personnel, including 80 Saudi and allied physicians and medics, participated in these courses. Confidence and competence in handling war casualties at all levels was enhanced greatly. Prepackaged courses such as BTLS enabled the rapid training of large numbers of medical personnel under challenging conditions.

A comparison of chest compressions between mechanical and manual CPR by monitoring end-tidal Pco 2 during human cardiac arrest

To compare the use of mechanical and manual chest compressions during cardiac arrest based on continuous monitoring of end-tidal PCO2 (PETCO2). Prospective, randomized, crossover design. Fifteen consecutive adults ranging in age from 33 to 78 years who presented in nontraumatic cardiac arrest to the emergency department of a large teaching hospital. Study protocols were begun late in the resuscitation after initial resuscitation attempts were unsuccessful. Patients received four alternating five-minute trials (two manual and two mechanical), being randomized to begin with either technique. Mechanical compressions were performed by a mechanical device at a compression depth of 2 in. Both mechanical and manual compressions were delivered at a rate of 80 with a ventilation delivered after every fifth compression. Persons performing manual CPR were experienced American Heart Association basic life support providers, and no person performed manual CPR more than once during the study period. No resuscitative drugs were administered during the study period. PETCO2 was monitored continuously; those performing manual CPR were blinded to the PETCO2 monitor. Data were analyzed with repeated-measures analysis of variance and Scheffé multiple comparisons with the alpha error rate set of .05. Mean PETCO2 during mechanical CPR was 13.6 +/- 4.14 mm Hg compared with 6.9 +/- 2.42 mm Hg during manually performed CPR (P < .001), a difference of 97%. Average mechanical CPR PETCO2 was higher in all cases. No patient was resuscitated successfully. Capnography also indicated that most CPR providers were inconsistent in their chest compressions. This study suggests that cardiac output produced with mechanical chest compressions is greater than that produced with manual compressions as demonstrated by the significantly higher PETCO2 levels during mechanical CPR. Reasons for this are unclear. In addition, monitoring of PETCO2 may help optimize chest compressions during CPR.