Blood glucose and cardiac resuscitation.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
L A Cobb
Publications and source records attributed to L A Cobb.
Reinforcing CPR skills without mannequin practice.
We studied the effectiveness of two refresher methods on skills that did not involve mannequin practice. Sixty-seven Seattle subjects trained one year earlier were pretested and randomly assigned to one of two treatments that covered the technique of one-rescuer CPR: reading a three-page review (n = 33); or viewing a 15-minute videotape (n = 34). Subjects were tested on a recording mannequin immediately after the refresher. Pretest scores were low on almost all skills. After treatment, both groups demonstrated significant improvement (P less than .01), especially on checking the carotid pulse, correct hand position, and ventilation volume. Although students who had watched the tape performed better on compression rate (P less than .05), there was virtually equivalent improvement on the other skills regardless of treatment. Both methods showed promise for reversing skills degradation without mannequin practice.
Evaluation Studies as Topic↗
Automatic external defibrillators: importance of field testing to evaluate performance.
A new automatic external defibrillator was tested first against a tape-recorded data base of rhythms and then during use by first-responding fire fighters in a tiered emergency system. The sensitivity for correctly classifying ventricular fibrillation and ventricular tachycardia was substantially less during clinical testing in 298 patients than would have been predicted from preclinical results: 52% of ventricular fibrillation analyses in patients were correctly classified versus 88% of episodes in the data base, and 22 versus 86%, respectively, for ventricular tachycardia (p less than 0.001). The detection algorithm was modified and evaluated further in another 322 patients. The modified detector performed substantially better than did the one that had been designed from prerecorded rhythms: with its use, 118 (94%) of 125 patients in ventricular fibrillation were counter-shocked compared with 91 (77%) of 118 similar patients with use of the initial algorithm (p less than 0.001). No inappropriate shocks were delivered. This improvement resulted in a shorter time to first shock (p less than 0.01) and more shocks being delivered for persistent or recurrent episodes of ventricular fibrillation (p less than 0.05). Of 620 patients treated with the automatic defibrillator, 243 (39%) had ventricular fibrillation; 57 (23%) of the 243 regained pulse and blood pressure before paramedics arrived, 141 (58%) were admitted to hospital and 71 (29%) were discharged.(ABSTRACT TRUNCATED AT 250 WORDS)
Algorithms↗
CPR training for patients' families: do physicians recommend it?
All Seattle-area cardiologists and 25 per cent of selected other physicians were queried by mail to determine whether they recommended CPR (cardiopulmonary resuscitation) training for families of their patients. Two-thirds reported that they advocated training for some patients' families, but only 52 per cent of cardiologists and 37 per cent of the others did so for families of at least half of the patients considered at risk. Physicians who had performed out-of-hospital CPR or had received advanced or recent training were more likely to recommend instruction.
Attitude of Health Personnel↗
Sudden cardiac death. Neural-cardiac interactions.
Explore the source record for details and available documents.
Animals↗
Environmental risk factors in coronary artery disease.
Explore the source record for details and available documents.
Coronary Disease↗
Cardiac arrest treated with a new automatic external defibrillator by out-of-hospital first responders.
Two hundred sixty patients in cardiac arrest were treated with an automatic external defibrillator by first-responding firefighters before arrival of paramedics. On average, first responders arrived 5 minutes before paramedics. Of 118 patients with ventricular fibrillation, 91 (77%) were administered shocks, 21 (23%) of whom had return of pulse and blood pressure by the time paramedics arrived. Fifty-six (62%) were admitted to the hospital and 30 (33%) survived. The survival rate for all 118 victims discovered with ventricular fibrillation was 27%. The device correctly classified the initial and all subsequent rhythms in 92 patients with asystole, 46 with electromechanical dissociation, and 22 others with presumed respiratory arrest; it did not deliver any inappropriate shocks to patients or to the rescuers using the device. An automatic external defibrillator can be used by first responders as an adjunct to basic life support, and its use may improve survival by shortening the time to defibrillation.
Allied Health Personnel↗
Smoking as a risk factor for recurrence of sudden cardiac arrest.
We obtained information about cessation of smoking in 310 survivors of out-of-hospital cardiac arrest who had been habitual cigarette smokers at the time of their arrest. Patients with coronary heart disease were stratified according to mortality risk on the basis of recognized criteria. The expected first-year rate of recurrent arrest ranged from 2 to 40 percent among the strata. Life-table analyses showed that reformed smokers had a lower incidence of recurrent arrest than patients who continued to smoke (19 vs. 27 percent at three years; P = 0.038 by one-sided test adjusted across strata). This effect occurred to varying degrees in all but the highest risk stratum. No differences in survival were observed for mortality due to other causes. It is possible that continued smoking in these patients led to acceleration of an ongoing atherosclerotic process, but the differences in early survival suggest that smoking may also act in the short term to enhance vulnerability to cardiac arrest.
Coronary Disease↗
Considerations for improving survival from out-of-hospital cardiac arrest.
Since the implementation of a paramedic system in Seattle, yearly survival rates from out-of-hospital cardiac arrest due to ventricular fibrillation have averaged 25% without any significant increase over the years. Outcome for cardiac arrest associated with other rhythms has been poor: when asystole was the first rhythm recorded, only 1% of patients survived; when electromechanical dissociation was initially present, only 6% survived. For cases of electromechanical dissociation, neither the type of rhythm nor the rate appear to influence outcome. Survival from ventricular fibrillation can be improved by shortening the delay to initiation of CPR and to defibrillation. When outcome in 244 witnessed arrests was related to the times to beginning CPR and to initial defibrillation, mortality increased 3% each minute until CPR was begun and 4% a minute until the first shock was delivered. New strategies that minimize delays appear to have the greatest promise for improving survival after cardiac arrest.
Ambulances↗
Exercise: a risk for sudden death in patients with coronary heart disease.
Although sudden arrhythmic death is usually unrelated to exertion, there is more than anecdotal evidence that strenuous exercise in patients with coronary heart disease carries an additional risk for sudden death. When cardiac arrest has been observed after exercise stress testing or within seconds after collapse associated with exertion, ventricular fibrillation has usually been present and has responded to the prompt application of a defibrillatory shock. Exertion-related cardiac arrest is typically a "primary" arrhythmic event not due to acute myocardial infarction. As estimated here, the additional risk of exercise for cardiac arrest may be more than 100-fold during or after a few minutes of vigorous exertion.
Adult↗
Factors influencing survival after out-of-hospital cardiac arrest.
Survival to hospital discharge was related to the clinical history and emergency care system factors in 285 patients with witnessed cardiac arrest due to ventricular fibrillation. Only the emergency care factors were associated with differences in outcome. Both the period from collapse until initiation of basic life support and the duration of basic life support before delivery of the first defibrillatory shock were shorter in patients who survived compared with those who died (3.6 +/- 2.5 versus 6.1 +/- 3.3 minutes and 4.3 +/- 3.3 versus 7.3 +/- 4.2 minutes; p less than 0.05). A linear regression model based on emergency response times for 942 patients discovered in ventricular fibrillation was used to estimate expected survival rates if the first-responding rescuers, in addition to paramedics, had been equipped and trained to defibrillate. Expected survival rates were higher with early defibrillation (38 +/- 3%; 95% confidence limits) than the observed rate (28 +/- 3%). Because outcome from cardiac arrest is primarily influenced by delays in providing cardiopulmonary resuscitation and defibrillation, factors affecting response time should be carefully examined by all emergency care systems.
Aged↗
Neurologic outcome and blood glucose levels during out-of-hospital cardiopulmonary resuscitation.
We examined the interrelations of outcome, time elapsed during cardiopulmonary resuscitation (CPR), and blood glucose levels drawn from 83 patients with out-of-hospital cardiac arrest. Levels rose significantly during CPR. Although slope and intercept of regression lines differed for those dying in the field and those admitted, regression lines were similar for those who awoke and never awoke after admission. These results suggest that the previously reported association between poor neurologic recovery and high blood glucose level on admission after cardiac arrest is best explained by prolonged CPR, leading to both higher rise of blood glucose and worse neurologic outcome.
Aged↗
Out-of-hospital sudden coronary death: rest and exercise radionuclide left ventricular function in survivors.
One hundred fifty-four survivors of out-of-hospital ventricular fibrillation (VF) with coronary artery disease underwent radionuclide ventriculography an average of 4.2 months after VF. All patients were studied at rest, and 91 of these patients were also studied during supine bicycle exercise. Clinical histories and 24-hour ambulatory electrocardiograms were also assessed, and patients were followed for an average of 3.1 years after ventriculography. The mean left ventricular (LV) ejection fraction (EF) at rest was 40 +/- 16%; in 34% of patients, it was 30% or less; in 37%, 31 to 50%; and in 29%, more than 50%. Regional LV wall motion was normal in 18%. The most severe segmental abnormality was hypokinesia in 22%, akinesia in 45% and dyskinesia in 14%. Wall motion abnormalities were usually located at the apex. During exercise, only 3% of patients (3 of 91) had a normal increase in EF of more than 5%, and the mean EF decreased from 42 to 38%. New exercise-induced wall motion abnormalities occurred in 30%. During the follow-up period, 54 patients died (35%): 48 from cardiac causes and 42 from unexpected and sudden causes. Predictors of death included EF at rest, presence of akinesia or dyskinesia on the ventriculogram at rest, the number of abnormal LV segments, history of congestive heart failure, history of acute myocardial infarction, absence of acute myocardial infarction at the time of VF and the presence of ventricular arrhythmia.(ABSTRACT TRUNCATED AT 250 WORDS)
Coronary Disease↗
CPR training in the community.
To provide a profile of potential rescuers of cardiac arrest victims, 1,271 randomly selected subjects were interviewed by telephone. Thirty-nine percent had formal instruction in cardiopulmonary resuscitation (CPR), 90% knew the emergency telephone number (911), and 5% had performed CPR. Subjects with training were significantly younger than those without (36 vs 48 years old) (P less than .001), and they had a lower incidence of known heart disease in family members (7% vs 15%) (P less than .001). More men than women were trained in CPR (44% vs 37%) (P less than .015). We recommend that efforts be undertaken to reach target groups of middle-age and older women for CPR training, and that physicians assume an active role in encouraging families of cardiac patients to learn this procedure.
Adult↗
Cardiovascular abnormalities in the athlete: recommendations regarding eligibility for competition. Task force VI: Arrhythmias.
Explore the source record for details and available documents.
Arrhythmias, Cardiac↗
Predictors of hospital mortality after out-of-hospital cardiopulmonary resuscitation.
Hospital mortality was examined in all patients successfully resuscitated from a witnessed out-of-hospital cardiac arrest due to ventricular fibrillation over a 1-yr period. Variables independently predictive of hospital mortality were a history of congestive heart failure before cardiac arrest, the time between collapse and initiation of CPR, and the time between collapse and restoration of circulation. The latter time was not related to either patient age or clinical history. Thus, hospital mortality was predetermined by prehospital factors, some of which can be changed.
Age Factors↗
Health status of survivors of cardiac arrest and of myocardial infarction controls.
We interviewed 308 survivors of out-of-hospital cardiac arrest and matched controls who had suffered a myocardial infarction. The Sickness Impact Profile (SIP) scores of controls were somewhat lower (better) than those of cases, but responses of cases and controls to additional questions about stair climbing, irritability and mood were virtually identical. Half as many (18 per cent) controls as cases (38 per cent) reported poorer memory function; nevertheless, 63 per cent of cases and 79 per cent of controls who had been working outside the home at the time of the event were employed at the time of the interview.
Activities of Daily Living↗
Amplitude of ventricular fibrillation waveform and outcome after cardiac arrest.
The amplitude of ventricular fibrillation found initially in 394 patients was compared to clinical and logistical findings at the time of cardiac arrest. Peak-to-peak amplitude averaged 0.55 +/- 0.25 mV; a very low amplitude (0.2 mV or less) or "fine" fibrillation was present in 66 patients (17%). The amplitude was not found to be related to clinical histories, but depended on the length of the period from collapse until start of basic life support (p = 0.004) and the delay until assessment by paramedics (p = 0.001). Survival rates were strongly associated with amplitude: only 4 patients (6%) with fine ventricular fibrillation survived, compared to 117 or 328 patients (36%) in whom the initial amplitude was higher (p less than 0.001). Patient outcome related to amplitude even after adjusting for clinical history and logistical delays (p less than 0.005). We conclude that fine ventricular fibrillation is in part the result of delay in initiation of treatment, and that fibrillation amplitude is a powerful indicator of outcome after cardiac arrest.
Aged↗