Factors associated with survival to hospital discharge among patients hospitalised alive after out of hospital cardiac arrest: change in outcome over 20 years in the community of Göteborg, Sweden.

OBJECTIVE: To describe the change in survival and factors associated with survival during a 20 year period among patients suffering from out of hospital cardiac arrest and being hospitalised alive. PATIENTS: All patients hospitalised alive in the community of Göteborg after out of hospital cardiac arrest between 1 October 1980 and 1 October 2000 were included. METHODS: Patient data were prospectively computerised with regard to factors at resuscitation. Data on medical history and hospitalisation were retrospectively recorded. Patients were divided into two groups (the first and second 10 year periods). SETTING: Community of Göteborg, Sweden. RESULTS: 5505 patients suffered from cardiac arrest during the time of the survey. Among them 1310 patients (24%) were hospitalised alive. Survival (discharged alive) was 37.5% during the first part and 35.1% during the second part (NS). The following were independent predictors of an increased chance of survival: ventricular fibrillation/tachycardia as the first recorded rhythm (odds ratio (OR) 3.46, 95% confidence interval (CI) 2.36 to 5.07); witnessed arrest (OR 2.50, 95% CI 1.52 to 4.10); bystander initiated cardiopulmonary resuscitation (OR 2.00, 95% CI 1.42 to 2.80); the patient being conscious on admission to hospital (OR 6.43, 95% CI 3.61 to 11.45); sinus rhythm on admission to hospital (OR 1.53, 95% CI 1.12 to 2.10); and treatment with lidocaine in the emergency department (OR 1.64, 95% CI 1.16 to 2.31). The following were independent predictors of a low chance of survival: age > 70 years (median) (OR 0.65, 95% CI 0.47 to 0.88); atropine required in the emergency department (OR 0.35, 95% CI 0.16 to 0.75); and chronic treatment with diuretics before hospital admission (OR 0.59, 95% CI 0.43 to 0.81). CONCLUSION: There was no improvement in survival over time among initial survivors of out of hospital cardiac arrest during a 20 year period. Major indicators for an increased chance of survival were initial ventricular fibrillation/tachycardia, bystander cardiopulmonary resuscitation, arrest being witnessed, and the patient being conscious on admission. Major indicators for a lower chance were high age, requirement for atropine in the emergency department, and chronic treatment with diuretics before cardiac arrest.

Experiences from treatment of out-of-hospital cardiac arrest during 17 years in Göteborg.

AIMS: To describe changes in different factors at resuscitation and survival in a 17-year survey of patients suffering from out-of-hospital cardiac arrest. METHOD: The investigation was carried out in the community of Göteborg with 450 000 inhabitants during 1981-1997 on all patients suffering out-of-hospital cardiac arrest in whom resuscitation was attempted. RESULTS: The number of cases per year, the proportion of witnessed arrests and the proportion of arrests of cardiac aetiology remained similar over time. There was an increase in median age from 68 to 73 years (P<0.0001), in the proportion of females from 27% to 33% (P=0.035) and in the proportion of patients receiving bystander cardiopulmonary resuscitation from 14% to 28% (P<0.0001) with time. There was a shortening of the median interval from collapse until defibrillation from 9 min to 6 min (P<0.0001) over time but a decrease in the occurrence of ventricular fibrillation as the initially recorded arrhythmia from 39% to 32% (P=0.022). There was an increase in the proportion of patients having a bystander witnessed cardiac arrest of cardiac aetiology being hospitalized alive from 32% to 45% (P<0. 0001 for change over time). The proportion of patients discharged alive from hospital increased from 16% to 29% until 1993, but thereafter decreased to 13% in 1997 (P=0.002 for change over time). CONCLUSION: In a survey covering 17 years of resuscitation of out-of-hospital cardiac arrest patients we found that the occurrence of ventricular fibrillation as the initially recorded arrhythmia decreased. There was an increase in age, in the proportion of females and in the use of bystander cardiopulmonary resuscitation. The interval between collapse and defibrillation was shortened. Survival changed over time with an increase until 1993 but with a decrease thereafter.

Has an intensified treatment in the ambulance of patients with acute severe left heart failure improved the outcome?

The aim of this study was to evaluate short- and long-term outcome prior to and after the introduction of a more intensified treatment in the ambulance of patients with acute severe heart failure. Consecutive patients with acute severe heart failure transported by the mobile coronary care unit (MCCU) in the community of Göteborg prior to and after the introduction of an intensified treatment (nitroglycerine, continuous positive airway pressure (CPAP) and furosemide). One hundred and fifty-eight patients were evaluated during each period. The median age was 77 and 76.5 years, respectively, and 52% and 42% were women. The proportion of patients given nitroglycerine in the ambulance was 4% and 68% in the two periods; the proportion of patients treated with furosemide was 13% and 84%, respectively. CPAP was used in less than 1% during period 1 and in 91% during period 2. On admission of the ambulance 60% had fulminant pulmonary oedema during period 1 versus 78% during period 2 (p<0.0001). On admission to hospital the opposite was found, 93% during period 1 versus 76% during period 2 (p<0.0001). The median serum creatinine kinase (CK-MB) maximum activity was 13 microkat/l during period 1 and 8 microkat/l during period 2 (p = 0.007). However, the mortality during the first year remained high during both periods (39.2% and 35.8%, p = 0.64). It is concluded that a more intensive treatment in the ambulance of patients with acute severe heart failure seems to have resulted in an improvement in symptoms during transport and less myocardial damage. However, no significant improvement in long-term mortality was observed.

Outcomes of patients hospitalized after out-of-hospital cardiac arrest in relation to sex.

OBJECTIVE: To describe characteristics and outcomes of patients hospitalized after out-of-hospital cardiac arrest in relation to sex. PATIENTS: All patients in the community of Göteborg who between 1980 and 1996 suffered out-of-hospital cardiac arrest and were hospitalized alive. METHODS: We calculated age-adjusted P values. RESULTS: In all 1038 patients were hospitalized alive of whom 29% were women. Women differed from men by being older and there being lower prevalences of previous acute myocardial infarction (AMI) and smoking and a higher prevalence of bronchial asthma among them. They had less commonly received cardio-pulmonary resuscitation (CPR) from bystanders (16 versus 25% of cases; P = 0.002) and were less commonly found to be in ventricular fibrillation when the ambulance crew arrived (55 versus 73% of cases; P < 0.0001). They were less commonly judged to have a cardiac etiology behind the arrest (87 versus 92% of cases; P = 0.016). Of women 31.3% could be discharged alive from hospital, compared with 41.8% of men (P = 0.001). While they were in hospital, women were less commonly subjected to exercise tests, coronary angiography, and coronary artery bypass grafting. CONCLUSION: Among patients who suffered out-of-hospital cardiac arrest and were hospitalized alive, women had less commonly received CPR from bystanders, were less commonly found in ventricular fibrillation, less commonly underwent coronary angiography and coronary artery bypass grafting and had a lower survival rate than did men.

Bioenergetic, functional and morphological consequences of postinfarct cardiac remodeling in the rat.

Despite recent advances in the treatment, severe chronic heart failure (CHF) remains a syndrome associated with high mortality. Therefore, the search for new agents to improve both patient symptoms and survival, as well as the pursuit for detailed knowledge about pathophysiology of the failing heart, will continue to depend on relevant animal models. Large acute myocardial infarction (MI) initiates complex changes in the geometrical, structural, and biochemical architecture of both infarcted and non-infarcted regions of ventricular myocardium, which can profoundly affect left ventricular function and prognosis. In this paper we present a new model for non-invasive cardiac (31)P MRS in the rat. Volume-selective (31)P magnetic resonance spectroscopy and echocardiography were used for evaluation of myocardial energy metabolism, cardiac morphology and function in rats 3 days and 3 weeks after induction of large MI. The phosphocreatine:adenosine triphosphate (PCr:ATP) ratio was decreased in rats with MI comparing with controls both at 3 days (1.6+/-0.06 vs 2.7+/-0.04; mean+/-s.e.m. P<0.0001) and 3 weeks (1.6+/-0.07 v 2.7+/-0.02 P<0.0001) postinfarct. The results from the study demonstrate that postinfarct cardiac remodeling is a rapid process of changes not only in cardiac geometry, structure and function but also in myocardial energy metabolism after large transmural MI in the rat.

There is a difference in characteristics and outcome between women and men who suffer out of hospital cardiac arrest.

OBJECTIVE: To evaluate whether there is a difference in characteristics and outcome in relation to gender among patients who suffer out of hospital cardiac arrest. DESIGN: Observational study. SETTING: The community of Göteborg. PATIENTS: All patients in the community of Göteborg who suffered out of hospital cardiac arrest between 1980 and 1996, and in whom cardiopulmonary resuscitation (CPR) was initiated. MAIN OUTCOME MEASURES: Factors at resuscitation and the proportion of patients being hospitalized and discharged from hospital. P values were corrected for age. RESULTS: The women were older than the men (median of 73 vs. 69 years; P < 0.0001), they received bystander-CPR less frequently (11 vs. 15%; P = 0.003), they were found in ongoing ventricular fibrillation less frequently (28 vs. 44%; P < 0.0001), and their arrests were judged to be of cardiac origin less frequently. In a multivariate analysis considering age, gender, arrest being due to a cardiac etiology, initial arrhythmia and by-stander initiated CPR, female gender appeared as an independent predictor for patients being brought to hospital alive (odds ratio 1.37; P = 0.001) but not for patients being discharged from hospital. CONCLUSION: Among patients who suffer out of hospital cardiac arrest with attempted CPR women differ from men being older, receive bystander CPR less frequently, have a cardiac etiology less frequently and are found in ventricular fibrillation less frequently. Finally female gender is associated with an increased chance of arriving at hospital alive.

Effect of intravenous metoprolol before hospital admission on chest pain in suspected acute myocardial infarction.

BACKGROUND: The aim of this study was to describe the effect of intravenous metoprolol on the intensity of chest pain before hospital admission in patients with suspected acute myocardial infarction AMI). METHODS AND RESULTS: Two hundred sixty-two patients with acute chest pain and suspected AMI were randomly assigned before hospital admission to either 5 mg morphine plus metoprolol 5 mg x 3 intravenously or 5 mg morphine plus intravenous placebo. Chest pain was evaluated on a 10-grade scale before and for 60 minutes after intravenous injection. One hundred thirty-four patients were randomly assigned to metoprolol and 128 to placebo. Among all patients randomized to metoprolol, the mean chest pain score was reduced by 3.0 +/- 1.9 arbitrary units AU) from before to after intravenous injection compared with 2.6 +/- 2.1 AU for placebo not significant). Among patients with an initially confirmed or strong suspicion of AMI, the corresponding figures were 3.1 +/- 1.8 AU for metoprolol and 2.2 +/- 1.6 AU for placebo P =.02). Among patients with only a vague or moderate suspicion of AMI, there was no difference. The treatment was well tolerated. CONCLUSIONS: When all patients were included in the analyses, there was no significant difference with regard to reduction of chest pain in the patients randomly assigned to metoprolol compared with placebo. A retrospective subgroup analysis indicated a beneficial effect of metoprolol among patients with an initially strong suspicion of or confirmed AMI. Further investigations are warranted to confirm this finding.

Hypertonic saline without or with dextran-70 in the treatment of experimental acute myocardial ischemia and reperfusion.

OBJECTIVE: To evaluate the effects of treatment with hypertonic saline without (HS) or with dextran (HSD) on cardiac function and myocardial damage during reperfusion after acute myocardial ischemia. DESIGN: A prospective, randomized, controlled study. SETTING: Animal laboratory at a university medical center. SUBJECTS: Three-month-old male, crossbred (Swedish landrace, Yorkshire, and Hampshire) pigs. INTERVENTIONS: The pigs were anesthetized and catheterized. A mid-sternal thoracotomy was performed, the pericardial sac was opened, and the left anterior descending artery was dissected free and occluded for 45 mins. A 10-min treatment period with 4 mL/kg HS (7.5%), HSD (7.5%/6%), or normal saline (0.9%) was started 5 mins before reperfusion. After a reperfusion period of 240 mins, biopsies from the ischemic area were taken. Thereafter, the hearts were excised and subjected to a staining procedure (triphenyltetrazoliumchloride and Evan's blue), and the left ventricle was sliced for assessment of the size of the infarcted area and the area at risk. MEASUREMENTS AND MAIN RESULTS: Central hemodynamics and myocardial performance were monitored before, during, and for 240 mins after 45 mins of acute left anterior descending artery occlusion. Alterations in blood chemistry and serum levels of markers of myocardial damage were repeatedly analyzed during the experimental procedure. Biopsies from the injured myocardium were analyzed for adenosine triphosphate, adenosine 5'-diphosphate, adenosine monophosphate, creatine phosphate, lactate, and glucose. Infarct sizes and areas at risk were planimetrically quantified. HS was not found to enhance, but rather to depress, cardiac performance at reperfusion, whereas HSD improved hemodynamics and myocardial contractility. HS or HSD administration was not found to increase the ischemia-induced myocardial damage. CONCLUSIONS: The administration of HSD but not HS will improve hemodynamics and myocardial performance during reperfusion after 45 mins of myocardial ischemia. The documented myocardial ischemic injury was not affected by any of the fluid therapies. Therefore, the present data do not support previously suggested detrimental effects of HS on myocardial ischemic injury.

Hypertonic saline infusion with or without dextran 70 in the reperfusion phase of experimental acute limb ischaemia.

OBJECTIVES: To study the efficacy of hypertonic fluid therapy on central haemodynamics, leg blood flow, and skeletal muscle metabolism at reperfusion after subtotal bilateral limb ischaemia. DESIGN: Prospective, randomised, controlled study, in pigs (n = 24). METHODS: Bilateral limb ischaemia was induced (aortic balloon catheter) and central haemodynamics, peripheral blood flow-thoracic fluid content, blood chemistry, and skeletal muscle metabolite levels were monitored. After 235 min of ischaemia infusion of normal 0.9% saline (NS), hypertonic 7.5% saline (HS), or HS in 6% dextran 70 (HSD) was started. Five minutes later the aortic balloon was deflated and the haemodynamic and metabolic alterations were studied for 180 min after reflow. RESULTS: Aortic occlusion resulted in haemodynamic alterations, reduced limb perfusion and metabolic changes indicative of tissue ischaemia. The haemodynamic support prior to, and following, deflation of the aortic balloon was more efficient for HS and HSD than for NS. Lactate clearance and restitution of high energy phosphagen levels in skeletal muscle were faster and more pronounced in the HS and HSD groups. CONCLUSIONS: Small-volume hypertonic saline, especially in combination with 6% dextran 70, will effectively reverse limb ischaemia induced haemodynamic and tissue metabolic disturbances.

Continuation of CPR on admission to emergency department after out-of-hospital cardiac arrest. Occurrence, characteristics and outcome.

AIM: To describe the occurrence, characteristics and outcome among patients with out-of-hospital cardiac arrest who required continuation of cardiopulmonary resuscitation (CPR) on admission to the emergency department. PATIENTS: all patients in the municipality of Göteborg who suffered out-of-hospital cardiac arrest, were reached by the emergency medical service (EMS) system and in whom CPR was initiated. Period for inclusion in study: 1 Oct. 1980-31 Dec. 1992. RESULTS: of 334 out-of-hospital cardiac arrests, 2,319 (68%) were receiving on-going CPR at the time of admission to hospital. Of these, 137 patients (6%) were hospitalized alive and 28 (1.2%) could be discharged from hospital. Of these patients, 39% had a cerebral performance categories (CPC) score of 1 (no cerebral deficiency), 18% had a CPC score of 2 (moderate cerebral deficiency), 36% had a CPC score of 3 (severe cerebral deficiency) and 7% had a CPC score of 4 (coma) at discharge. Among patients discharged. 76% were alive after 1 year. CONCLUSION: among consecutive patients with out-of-hospital cardiac arrest, CPR was ongoing in 68% of them on admission to hospital. Among these patients, 6% were hospitalized alive and 1.2% were discharged from hospital. Thus, among patients with ongoing CPR on admission to hospital, survivors can be found but they are few in numbers and extensive cerebral damage is frequently present.

Effects of hypertonic saline on myocardial function and metabolism in nonischemic and ischemic isolated working rat hearts.

OBJECTIVE: To study the direct effects of hypertonic saline on the function of non-ischemic and ischemic myocardium by the use of an isolated working rat heart model. DESIGN: A prospective, randomized, controlled study. SETTING: Animal laboratory at a university medical center. SUBJECTS: Adult Wistar rats (n = 32) of both sexes. INTERVENTIONS: The heart was excised via thoracotomy in anesthetized rats and prepared for antegrade perfusion at a constant heart rate in an antegrade perfusion apparatus at predetermined preloads and afterloads. Hearts were exposed to ischemia, ischemia followed by repeated hypertonic saline treatment, or repeated hypertonic saline without preceding ischemia. Myocardial ischemia was induced by decreasing the mean aortic pressure to 25 mm Hg. MEASUREMENTS AND MAIN RESULTS: Variables that were measured or calculated included the following: left atrial pressure; mean aortic pressure; heart rate; coronary flow; aortic flow; cardiac output; stroke volume; PO2, electrolyte content, osmolality, and lactate concentration of the perfusate and/or venous effluent; myocardial oxygen extraction; myocardial oxygen consumption; and myocardial lactate efflux. Ischemia resulted in pronounced impairment of myocardial function and metabolism. Hypertonic saline administration during ischemia induced an additional transient myocardial depression. In the nonischemic heart, a transient myocardial-depressant effect after hypertonic saline administration was also seen. CONCLUSIONS: The present results from an isolated working heart preparation show that hypertonic saline exerts myocardial-depressive effects in the ischemic as well as in the nonischemic heart. Systemic rather than direct myocardial effects may therefore be responsible for the previously reported beneficial hemodynamic effects of hypertonic saline in shock treatment.

Protective effects of halothane but not isoflurane against global ischaemic injury in the isolated working rat heart.

The effects of equi-anaesthetic concentrations of halothane (HAL) and isoflurane (ISO) on myocardial performance, perfusion, oxygenation and lactate release were studied before, during and after a low-flow, global ischaemic insult in isolated, paced rat left heart preparations. An antegrade perfusion technique was used, where left atrial pressure (LAP) and mean aortic pressure (MAP) could be altered independently of each other. Aortic flow, coronary flow (CF) and PO2 in venous coronary effluent were continuously recorded and stroke volume, myocardial oxygen consumption (MVO2) and myocardial oxygen extraction as well as lactate release were calculated. The hearts were exposed for at least ten minutes to the perfusate without (control, n = 10) or with HAL (n = 10) or ISO (n = 10) at a MAP of 80 mmHg (10.4 kPa) and a LAP of 7.5 mmHg (1.0 kPa). After baseline measurements, MAP was reduced to 25 mmHg (3,2 kPa) for a total of nine minutes. Thereafter MAP was increased to 80 mmHg (10.4 kPa) for another nine minute period. During the whole experimental procedure, LAP was maintained at 7.5 mmHg (1.0 kPa) and heart rate at 325 beats per minute. In the pre-ischaemic control period, MVO2 was lower with HAL compared to ISO (P < 0.05) and control (P < 0.05). Stroke volume was also lower with HAL compared to control (P < 0.05). During hypoperfusion, lactate release was twice as high in the control group (P < 0.01) and with ISO (P < 0.01) compared to HAL.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of osmolality and ionic composition of resuscitation fluids for treatment of acute blood loss in the spontaneously hypertensive rat (SHR).

The spontaneously hypertensive rat (SHR) has a deficient glucose mobilization in response to blood loss. Treatment of blood loss with hypertonic glucose might consequently be advantageous in SHR, but the importance of osmolality as compared to ionic composition of resuscitation fluids is still not fully elucidated. Therefore, SHR (n = 32) were subjected to hemorrhage (30% of calculated blood volume) followed by treatment with (1) hypertonic saline (HS; 4.5 ml/kg of 7.5% NaCl, 2,400 mOsm/L), (2) hypertonic glucose (HG; 4.5 ml/kg of 42.3% solution, 2,400 mOsm/L), and (3) normal saline (NS; 37.5 ml/kg of 0.9% NaCl) to provide an equal sodium load as with HS. All fluid regimens increased (P < 0.001 vs. control) mean arterial pressure (MAP). Hemodilution was more pronounced after HS and NS than after HG. Hypernatremia was evoked by HS. The hyperglycemic response to hemorrhage was intensified by HG, but it was accompanied by increased blood lactate levels. All three treatment regimens prolonged posthemorrhagic times until death (P < 0.01-0.05) (mean values: NS 363 min; HS 170 min; HG 146 min; nontreated controls 60 min). It is concluded, on the basis of hemodynamic, metabolic, and times-until-death data, that although treatment with small-volume HS seems superior to small-volume HG, an equal load of sodium given as NS is more effective for resuscitation after blood loss than HS in SHR.