Early predictors of mortality for hospitalized patients suffering cardiopulmonary arrest

Few if any prearrest or intraarrest variables have been identified as highly predictive of inhospital mortality following cardiopulmonary arrest. A total of 310 consecutive patients requiring advanced cardiac life support during the calendar years 1985 and 1986 were reviewed with respect to eight specific variables. These included age, diagnosis, location, mechanism of the event, duration of resuscitation, whether the event was witnessed or unwitnessed, the initial observed rhythm and medications administered. A total of 37.1 percent of the patients were successfully resuscitated, but only 9.7 percent survived until discharge. Factors strongly associated with inhospital mortality included unwitnessed events (p = 0.0316), the need for epinephrine (p = 0.0003), identification of electromechanical dissociation or asystole as initial rhythms (p = 0.0000), and cardiac vs respiratory mechanism of arrest (p = 0.0000).     

Cardiopulmonary bypass vs CPR as treatment for prolonged canine cardiopulmonary arrest

Although in vitro studies have demonstrated functional recovery of neurons after prolonged ischemia, in vivo experience with patients resuscitated from cardiopulmonary arrest demonstrates much less cerebral resistance to global ischemia. The purpose of our investigation was to compare the effectiveness of femoro-femoral veno-arterial cardiopulmonary bypass (CPB) to standard cardiopulmonary resuscitation in the treatment of prolonged cardiopulmonary arrest. Ten mongrel dogs were electrically fibrillated and left in cardiopulmonary arrest without any therapy for 12 minutes. Subsequently, either CPB (n = 5) or CPR (n = 5) was initiated and resuscitation attempted according to a standardized protocol that included administration of the calcium channel blocker lidoflazine in an effort to optimize cerebral and myocardial recovery. If there was return of spontaneous circulation, the animal was managed in an intensive care setting with invasive hemodynamic monitoring and ventilatory support for up to nine hours. Neurologic function was graded using a standardized neurologic deficit scoring (NDS) system at 12 hours after insult and daily for one week or until death. Prearrest hemodynamic and metabolic parameters were comparable in both groups (P greater than .05). All CPB animals were resuscitated successfully and alive at 24 hours after insult as opposed to none in the CPR group (P less than .005). In addition, three of the CPB animals were neurologically normal at final grading with NDS scores of zero. The other two CPB animals had persistent severe neurologic impairment and a mean NDS score of 51%. Thus CPB is more effective than CPR in the treatment of prolonged cardiopulmonary arrest. The improved outcome probably results primarily from improvement in blood flow with CPB.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pre-arrest morbidity and other correlates of survival after in-hospital cardiopulmonary arrest

PURPOSE: Recent reports on the use of in-hospital cardiopulmonary resuscitation (CPR) have failed to provide an applicable method to identify patients who have little chance of surviving CPR. We prospectively evaluated the clinical characteristics and outcome of 140 consecutive hospitalized patients who had cardiopulmonary arrest and received CPR, and we propose a method for predicting survival in this setting. PATIENTS AND METHODS: The study period was July 1 through December 31, 1985, and the patient population consisted of 91 men and 49 women (age range, 18 to 92 years). We devised a multifactorial scoring system, the Pre-Arrest Morbidity (PAM) Index, to evaluate pre-arrest morbidity in individual patients. RESULTS: Seventy-seven (55%) of these patients were successfully resuscitated, 34 (24.3%) were discharged from the hospital alive, and 29 (20.7%) were long-term survivors (alive three months after discharge). Multivariate analysis of pre-arrest clinical variables demonstrated a significant association with mortality for hypotension, azotemia, and age 65 years or older, although none of these factors was absolutely predictive of a fatal outcome. The PAM Index was found to correlate inversely with the frequency of successful resuscitation, and the probability of short-term and long-term survival after CPR. Patients with PAM scores of 7 or greater had an extremely low likelihood of long-term survival (less than 15%), and no patient with a score of more than 8 survived to discharge. When the PAM score was considered in multivariate analysis of pre-arrest variables, it became the only significant independent predictor of mortality. CONCLUSION: The PAM Index may be useful in identifying patients in whom CPR may be ineffective.     

Unexpected findings and complications at autopsy after cardiopulmonary resuscitation (CPR)

To evaluate the importance of diagnoses undetected before cardiac arrest in the hospital, we studied autopsy findings on 130 patients who died after an attempt at cardiopulmonary resuscitation (CPR). We also studied the complications that occurred in these patients as a result of CPR. Twenty-one percent of the patients had at least one complication as a result of CPR. Patients resuscitated on the wards were more likely to have a complication than those treated in the intensive care unit. This suggests that more proficient technique in CPR may reduce morbidity from this procedure. In 14% of the cases, there was a major missed diagnosis. The two diseases most frequently undetected clinically were ischemic bowel and pulmonary embolus, which together accounted for 89% of all major missed diagnoses discovered at autopsy. We conclude that diseases that require a high prior clinical suspicion (bowel infarction and pulmonary embolus) are common accompaniments of cardiac arrest in the hospital. Consideration of these diagnoses in critically ill patients may prevent future cardiac arrest and death from pulmonary embolus and ischemic bowel.     

Outcome of cardiopulmonary resuscitation in the intensive care setting.

BACKGROUND--Although cardiopulmonary resuscitation (CPR) has been shown to be most effective in a monitored setting, previous studies have focused primarily on patients with acute cardiac events rather than chronic progressive disease. This study examined the outcome of CPR in the medical and surgical intensive care units where patients often have acute illness superimposed on chronic underlying conditions. METHODS--We present a retrospective chart review of all patients undergoing CPR in medical and surgical intensive care units during a 2-year period. RESULTS--One hundred fourteen charts were reviewed. Patient mean age was 59 years. The primary underlying disease was malignancy in 29 (25%), vascular disease in 20 (18%), chronic liver disease in eight (7%), end-stage renal disease in six (5%), chronic obstructive pulmonary disease in five (5%), and other conditions in 46 (40%) patients. Although 50 (44%) of the patients were initially resuscitated, only six (5%) ultimately survived to hospital discharge. Only one of 29 patients with malignancy and one of 39 septic patients survived. Age, sex, and Acute Physiology and Chronic Health Evaluation II scores were similar among survivors and nonsurvivors. Furthermore, four of the six survivors died within 1 year of discharge, and the two others had severe disabilities. CONCLUSIONS--Patients with chronic medical conditions undergoing CPR even in an intensive care unit setting seldom survive to hospital discharge. Even among the few survivors, the near term prognosis is poor. Therefore, the decision to perform CPR should take into account underlying chronic medical conditions and not merely the setting of the arrest.     

Analysis of factors associated with successful cardiopulmonary resuscitation in non-traumatic dead-on-arrival patients in emergency department

Out-of-hospital cardiopulmonary arrest has a dismal prognosis. Successful resuscitation of these patients depends on the "chain of survival". In Taiwan, the emergency medical services (EMS) system is under development and the links of "chain of survival" are weak and frequently broken. A 2-year retrospective study was conducted from January, 1999, to December, 2000 to evaluate the factors of successful cardiopulmonary resuscitation (CPR) in non-traumatic DOA patients in ED. Of 175 studied patients, 51 patients (29.1%) were successfully resuscitated with return of spontaneous circulation (ROSC), but only 7 patients (4%) survived to hospital discharge. Most successfully resuscitated patients (84.3%) regained their vital signs within 30 minutes. There were no significant differences in age, sex, vehicle of transportation, administration of prehospital CPR or not, EMS response interval, on-scene duration, and scene-to-hospital interval between patients with ROSC and without ROSC. Compared with asystole cardiac rhythm, patients with pulseless electrical activity (PEA) had a higher successful resuscitation rate (p = 0.001), but no significant differences existed between patients with ventricular fibrillation/ventricular tachycardia (VF/VT) and PEA or VF/VT and asystole. However, there were no significant differences in the survival discharge rate among patients with different initial cardiac rhythms in ED.     

Incidence of circulatory arrest in patients with acute myocardial infarction in coronary unit. Mechanism of their genesis and factors conditioning successful resuscitation

The incidence, circumstances, and mechanism of development of cardiac arrest in 786 patients with myocardial infarction treated at a coronary care unit within a five-year period were studied and clinical factors are analysed with respect to success of resuscitation. One or more episodes of cardiac arrest occurred in a total of 156 patients (19.8%). Of these, 25 (16.0%) were successfully resuscitated and 131 (84.0%) died. At the clinical ward where the patients had been transferred after the acute stage, cardiac arrest occurred in additional 22 patients, of whom two were successfully resuscitated. Thus, the total number of successfully resuscitated patients throughout the five-year period was twenty-seven. The results of resuscitation were poorer in elderly patients, in those with anterior infarction, and above all in patients with severe symptoms of mechanical heart failure. Anamnestic factors (chronic angina pectoris, previous myocardial infarction, hypertension, diabetes mellitus, ischaemic disease of the lower limbs) were not significantly associated with the results of resuscitation. Primary ventricular fibrillation was the principal mechanism of cardiac arrest in 24 of the 27 patients successfully resuscitated, and its total incidence in the investigated group was 3%. The prognosis of resuscitation in patients with primary ventricular fibrillation was very good, and in all of them the resuscitation was successful and permanent.     

Resuscitation time in ventricular fibrillation — a prognostic indicator

Length of resuscitation in prehospital ventricular fibrillation patients was studied to define its relationship to survival. Five hundred sixty-five patients presenting with the initial rhythm of ventricular fibrillation to the Milwaukee County Paramedic System between January 1978 and April 1982 were resuscitated successfully. Pediatric patients and patients with trauma, poisoning, and drowning were excluded. Of the 565 resuscitated patients, 262 (46%) were discharged alive and 303 (54%) died during hospitalization. For all 565 patients the resuscitation time and times from arrival of paramedics until the first sustained pulse were plotted against survival to define a curve. The curve demonstrated rapidly declining survival rates for resuscitation time up to 20 minutes; thereafter, survival declined more gradually with respect to resuscitation time. The mean resuscitation time for those eventually discharged alive was 12.6 minutes, which was statistically shorter (P less than .0001) than the mean resuscitation time of 23.9 minutes for those who eventually died. The overall survival curve of witnessed arrest patients was not statistically different from that of unwitnessed patients. The survival curve of those patients receiving bystander cardiopulmonary resuscitation (CPR) was similar to the curve of those who received no CPR. We conclude that resuscitation time is a heretofore undefined significant predictor of survival of resuscitated prehospital ventricular fibrillation patients.     

Cost-effectiveness of training unselected laypersons in cardiopulmonary resuscitation and defibrillation

PURPOSE: The cost-effectiveness of cardiopulmonary resuscitation (CPR) and defibrillation training for laypersons unselected for risk of encountering cases of cardiac arrest is not known. We compared the costs and health benefits of alternative resuscitation training strategies for adults without professional first-responder duties who are at average risk of encountering cases of out-of-hospital cardiac arrest. METHODS: We constructed a cost-effectiveness analytic model. Data on cardiac arrest epidemiology and the effectiveness of CPR/defibrillation training were obtained from the medical literature. Instructional costs were determined from a survey of training programs. Downstream cardiac arrest survivor quality-adjusted life expectancy and long-term health care costs were derived from prior studies. We compared three strategies for training unselected laypersons: CPR/defibrillation training alone, training combined with home defibrillator purchase, and no training. The main outcome measures were total instructional costs for trainees combined with health care costs for additional cardiac arrest survivors, and quality-adjusted survival for additional patients resuscitated by trainees. RESULTS: CPR/defibrillation training yielded 2.7 quality-adjusted hours of life at a cost of 62 US dollars per trainee (202,400 US dollars per quality-adjusted life-year [QALY] gained). Training laypersons in CPR/defibrillation with subsequent defibrillator purchase cost 2,489,700 US dollars per QALY. In contrast, CPR/defibrillation training cost less than 75,000 US dollars per QALY if trainees lived with persons older than 75 years or with persons who had cardiac disease, or if total training costs were less than 10 US dollars. CONCLUSION: Training unselected laypersons in CPR/defibrillation is costly compared with other public health initiatives. Conversely, training laypersons selected by occupation, low training costs, or having high-risk household companions is substantially more efficient.     

Insulin and glucose levels during CPR in the canine model

Cardiopulmonary arrest and resuscitation produces tremendous physiological stress with resultant biochemical derangements. We undertook this study to determine insulin and glucose levels during cardiopulmonary arrest in the canine model. Baseline insulin and glucose levels were obtained from an ascending aortic arch catheter in six mongrel dogs. Ventricular fibrillation was induced by an electrical stimulus and ventilation was terminated. After five minutes of fibrillation, cardiopulmonary resuscitation (CPR) was initiated using external, mechanical CPR and a continuous epinephrine infusion at 5 micrograms/kg/min. Serum insulin and glucose levels were repeated 15 minutes after beginning CPR. Mean blood glucose 15 minutes after initiation of resuscitation (379 +/- 114 mg/dL) was significantly increased from prearrest levels (124 +/- 29 mg/dL, P less than .01). Mean serum insulin 15 minutes after initiation of resuscitation (11.3 +/- 3.3 microU/mL) was significantly decreased compared to prearrest levels (16.2 +/- 6.0 microU/mL, P less than .05). During ischemia, the myocardium becomes dependent primarily on glucose as a source of energy. Inappropriately low insulin levels during CPR may adversely affect an already compromised myocardial glucose metabolism. Further investigation is needed to determine the utility of insulin infusion during CPR.     

Comparison of epinephrine and phenylephrine for resuscitation and neurologic outcome of cardiac arrest in dogs

A study was done comparing resuscitability and 24-hour neurologic outcome in fibrillating dogs that were treated with either phenylephrine (a primary alpha agonist) or epinephrine. Ventricular fibrillation was induced electrically in 18 dogs. After three minutes, standard CPR was instituted using a mechanical resuscitator. Dogs were given phenylephrine or epinephrine at nine minutes and defibrillation was attempted at 12 minutes. Dogs underwent hemodynamic monitoring and pharmacologic support, if necessary, for an additional 90 minutes. At four, eight, 12, and 24 hours, a standard neurologic examination was performed and deficit scores were assigned by an observer blinded to the drug given. Fourteen of the 18 dogs were resuscitated. There were no statistically significant differences in the epinephrine- or phenylephrine-treated groups with regard to number of animals resuscitated, time and interventions required for resuscitation, initial cardiac rhythm post resuscitation, or occurrence of ventricular fibrillation during resuscitation. No differences were found in arterial, central venous, or myocardial perfusion pressures during CPR. Phenylephrine-treated dogs tended to have higher mean pressures in the critical care period (15 to 30 minutes), although this was not significant. Total neurologic deficit scores were 127.8 +/- 83.8 for the phenylephrine-treated group and 129.4 +/- 87.4 for the epinephrine group. No significant differences were found in the level of consciousness, cranial nerve function, motor skills, or general behavior scores. We conclude that there is no difference in neurologic or cardiovascular outcome when phenylephrine is compared to epinephrine in a canine model of cardiac arrest and cardiopulmonary resuscitation.     

Comparison of standard external CPR, open-chest CPR, and cardiopulmonary bypass in a canine myocardial infarct model

STUDY OBJECTIVES: After cardiac arrest, open-chest CPR (OCCPR) and cardiopulmonary bypass (CPB) have demonstrated higher resuscitation rates when compared individually with standard external CPR (SECPR). We compared all three techniques in a canine myocardial infarct ventricular fibrillation model. TYPE OF PARTICIPANTS: Twenty-six mongrel dogs were block-randomized to receive SECPR and advanced life support (nine), CPB (nine), or OCCPR (eight). DESIGN AND INTERVENTIONS: All dogs received left anterior descending coronary artery occlusion followed by four minutes of ventricular fibrillation without CPR and eight minutes of Thumper CPR. At 12 minutes, dogs received one of three resuscitation techniques. After resuscitation, all animals received four hours of intensive care. Animals that were resuscitated had histochemical determination of ischemic and necrotic myocardial areas. MEASUREMENTS: Intravascular pressures were measured and coronary perfusion pressure was calculated during baseline, cardiac arrest, resuscitation, and postresuscitation periods. Percent necrotic myocardium, percent ischemic myocardium, and necrotic-to-ischemic ratios were determined for resuscitated animals. Epinephrine dosage and number of countershocks were determined for each group. MAIN RESULTS: Nine of nine CPB and six of nine OCCPR, compared with two of eight SECPR animals, were resuscitated (P less than .01). Three of nine CPB and OCCPR and two of eight SECPR dogs survived to four hours (P = NS). Coronary perfusion pressure two minutes after institution of technique was significantly higher with CPB (75 +/- 37 mm Hg) and OCCPR (56 +/- 31 mm Hg) than in SECPR animals (16 +/- 16 mm Hg, P less than .04). Epinephrine required for resuscitation was significantly less with CPB (0.10 +/- 0.02 mg/kg) than for SECPR (0.28 +/- 0.11 mg/kg, P less than .002). The ratio of necrotic to ischemic myocardium at four hours was significantly lower with CPB (0.15 +/- 0.31) and OCCPR (0.39 +/- 0.25) than for SECPR (1.16 +/- 0.31, P less than .02). CONCLUSION: OCCPR and CPB produce higher coronary perfusion pressures and improved resuscitation rates from ventricular fibrillation when compared with SECPR in this canine myocardial infarct cardiac arrest model. CPB and OCCPR yielded similar resuscitation results, although less epinephrine was required with CPB.     

Factitious lowering of the serum potassium level after cardiopulmonary resuscitation. Implications for evaluating the arrhythmogenicity of hypokalemia in acute myocardial infarction

Hypokalemia has been suggested as a predisposing factor to the development of fatal arrhythmias in acute myocardial infarction. Evidence cited to support this concept has been derived largely from studies in which the determination of the serum potassium level was made following a cardiac arrhythmia and/or arrest, and often following cardiopulmonary resuscitation (CPR); this postresuscitation potassium level has been considered to be representative of the prearrest value. In the patient described herein, serial determinations of serum potassium obtained fortuitously before and intentionally following sudden unexpected cardiac arrest in a hospitalized patient demonstrate that the prearrest serum potassium level cannot be inferred from electrolyte values obtained after CPR.     

Results of Attempted Cardiopulmonary Resuscitation of Patients Dying Suddenly outside the Hospital in Reykjavik and the Surrounding Area, 1976–1979

ABSTRACT. Cardiopulmonary resuscitation (CPR) was attempted in 222 cases of sudden death at the City Hospital, Reykjavik, during 1976–79. Of the 68 patients (31%) successfully resuscitated, 47 died in the hospital and 21 (9%) were discharged, 17 in good mental and physical condition. The mean combined response and transport time was 12.1 min and the ambulance mean time of response 7.3 min. The first ECG revealed considerable prognostic indications. Of the 90 patients who had ventricular fibrillation on admission, 42 (47%) were successfully resuscitated and 18 (20%) were subsequently discharged. Among 114 patients with asystole, resuscitation was successful in 23 (20%) and two (2%) were discharged. Immediate first aid in situ had a definite prognostic influence. These results compare favourably with those obtained elsewhere where the organization of first aid and emergency transport is similar. They do not, however, match the results achieved by fully specialized resuscitation teams trained to operate outside the hospital. Results of CPR of patients with cardiac arrest out of hospital in Reykjavik show increasing improvement over the years. This may be partly explained by a considerable public debate on this issue in 1978 and subsequent streamlining of activities.     

Myocardial oxygen requirements during experimental cardiopulmonary resuscitation.

OBJECTIVE: The aims were to determine myocardial oxygen requirements during cardiopulmonary resuscitation (CPR), and to test the hypothesis that endogenous catecholamines have a major effect on myocardial oxygen requirements in this setting. METHODS: Myocardial oxygen consumption (MVO2) was measured during 20 minutes of CPR in eight anaesthetised dogs. Coronary blood flow was maintained at prearrest levels using an external pump to provide a permissive level of oxygen delivery during ventricular fibrillation. Oxygen content was measured in arterial and coronary sinus blood samples under prearrest conditions and at 5 min intervals during CPR. Four dogs were given propranolol (1 mg.kg-1) following the 5 min measurements. RESULTS: MVO2 averaged 108.7(SEM 12.8)% of the initial prearrest values after 5 min CPR (n = 8). After 10 min CPR, MVO2 fell to 53.8(13.3)% of the initial prearrest values in the subset of animals given propranolol after the 5 min measurements (n = 4), but remained at prearrest levels in untreated animals (p < 0.05 for an interactive effect between treatment and time). MVO2 subsequently tended to decrease with time in untreated animals, but remained a high percentage of prearrest values throughout the 20 min period of CPR. CONCLUSIONS: These findings suggest that endogenous sympathetic stimulation of the fibrillating heart results in high myocardial oxygen requirements during CPR.     

Immediate countershock versus cardiopulmonary resuscitation before countershock in a 5-minute swine model of ventricular fibrillation arrest

STUDY OBJECTIVE: Prior laboratory and clinical studies demonstrate that cardiopulmonary resuscitation (CPR) preceding countershock of prolonged ventricular fibrillation (VF) increases the likelihood of successful cardiac resuscitation. The lower limit of VF duration at which time preshock CPR provides no benefit has not been specifically studied. The purpose of this study was to compare countershock and cardiac resuscitation outcome between immediate countershock of VF of 5-minute duration and CPR without drug therapy before countershock in a swine model. METHODS: VF was induced in anesthetized and instrumented swine. After 5 minutes of VF, animals received 1 of 2 treatments. Animals in group 1, a "historical" control group (n=20), received immediate countershock followed by CPR and repeated shocks if needed. Group 2 animals (n=11) received CPR for 90 seconds preceding countershock, then continued CPR and repeated countershock if necessary. Drugs were not administered to either group, and resuscitation efforts were discontinued if a perfusing rhythm was not restored within 10 minutes of the first countershock. First shock success rate (defined as termination of VF), the number of shocks required to terminate VF, and the cardiac resuscitation rate were compared between groups. RESULTS: The first shock terminated VF in 13 of 20 group 1 animals and 2 of 11 group 2 animals (P =.023). All but 1 animal in group 1 developed pulseless electrical activity after countershock. All but 1 animal in group 1 were eventually successfully resuscitated with CPR and repeated shocks if necessary. Four group 2 animals could not be resuscitated (P =.042). CONCLUSION: Although effective in improving outcome of prolonged VF, CPR preceding countershock of VF of 5-minute duration does not improve the response to the first shock, decrease the incidence of postshock pulseless electrical activity, or the rate of return of circulation. In this study, CPR preceding countershock resulted in a significantly lower cardiac resuscitation rate.     

Neurologic benefits from the use of early cardiopulmonary resuscitation

The efficacy of bystander CPR in resuscitation from cardiac arrest when defibrillation is available within five to six minutes has been questioned. Epidemiologic studies from different cities have shown conflicting results. We conducted a study to determine the effect of early CPR versus no CPR on resuscitability, 24-hour survival, and neurologic deficit in an animal model of cardiac arrest. Twenty-two mongrel dogs were subjected to five minutes of electrically induced ventricular fibrillation. In 11 dogs, closed-chest massage and ventilation with room air was begun immediately and was continued for five minutes. The other 11 dogs received no CPR. At five minutes defibrillation was attempted and advanced cardiac life support (ACLS) protocols were followed until the animal was resuscitated or died. No statistical difference in resuscitability or 24-hour survival between the two groups was demonstrated. Eight of 11 "early CPR" animals were resuscitated and survived 24 hours; six of 11 "no CPR" dogs were resuscitated, and five lived for 24 hours. A significant difference was demonstrated by the Student t test in neurologic deficit and ease of resuscitation. "Early CPR" dogs had no neurologic deficit, while "no CPR" dogs had a 41% deficit (P less than .01). "Early CPR" dogs were resuscitated in significantly less time once ACLS was started (29 versus 317 seconds), and required less electrical energy (100 versus 560 J), fewer countershocks (1.3 versus 4.0), and less epinephrine (0.1 versus 1.7 mg) than did "no CPR" animals. In this animal model of cardiac arrest, early CPR was shown to be beneficial to neurologic function and ease of resuscitation, even when ACLS was provided within five minutes.     

Survival after out-of-hospital cardiac arrest in elderly patients. Belgian Cerebral Resuscitation Study Group.

STUDY OBJECTIVES: To study whether age of the cardiac arrest patient is related to prognostic factors and survival. STUDY DESIGN: Retrospective analysis of a prospective registration of cardiac arrest events in the mobile ICUs of seven participating hospitals. STUDY POPULATION: Two thousand seven hundred seventy-six out-of-hospital cardiac arrests in which advanced life support was initiated. Cardiac arrests with a precipitating event requiring specific therapeutic consequences and with specific prognosis were not included in the analysis (eg, trauma, exsanguination, drowning, sudden infant death syndrome). RESULTS: Neither resuscitation rate (23%) nor mortality caused by a neurologic reason (9%) was significantly different between age groups. Mortality after CPR of non-neurologic etiology was significantly higher in the elderly patient (younger than 40 years, 16%; 40 to 69 years, 19%; 70 to 79 years, 30%; 80 years or older, 34%; P less than .005) and had a negative effect on survival in resuscitated elderly patients (P less than .05). Elderly patients more frequently had a dependent lifestyle before the arrest (P less than .025), an arrest of cardiac origin (P less than .001), electromechanical dissociation as the type of cardiac arrest (P less than .025), and a shorter duration of advanced life support in unsuccessful resuscitation attempts (r = -.178, P less than .0001). CONCLUSION: Because survival two weeks after CPR was not significantly different between age groups, we suggest that decision making in CPR should not be based on age but on factors with better predictive power for outcome and quality of survival.     

Cardiac sudden death. Testing of an extra-hospital emergency system

From December 1979 to April 1984, 266 victims of cardiac arrest outside the hospital in the metropolitan area of Florence received advanced cardiopulmonary resuscitation by a system for medical emergencies. 69 patients (25.9%) were successfully resuscitated and 42 (15.7%) were discharged alive from hospital without any neurological damage. The time delay between the onset of the cardiac arrest and the cardio-pulmonary resuscitation, the cardiac rhythm present on arrival of rescue squad, the degree of congestive heart failure immediately before the cardiac arrest and the neurological deficit after resuscitation significatively influenced immediate and late outcome.     

Potential for injury: trauma after cardiopulmonary resuscitation

Cardiopulmonary resuscitation (CPR) is a technique that saves lives and is a measure that critical care practitioners use without hesitation. Potential complications from CPR, however, include injury. The reported incidence of such injuries ranges from 21% to more than 65%. Unfortunately, even properly executed CPR can lead to injury. The incidence of most common injuries, such as injury to the skin, bony thorax, and upper airway, may be limited by performance of proper basic and advanced life support. Limiting these injuries is important. Discovering them in successfully resuscitated victims, however, is critical to long-term recovery and rehabilitation. As future techniques for CPR evolve, further research needs to focus on those techniques that limit the potential for injury.