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Effects of a medical emergency team on reduction of incidence of and mortality from unexpected cardiac arrests in hospital: preliminary study.

OBJECTIVES: To determine whether earlier clinical intervention by a medical emergency team prompted by clinical instability in a patient could reduce the incidence of and mortality from unexpected cardiac arrest in hospital. DESIGN: A non-randomised, population based study before (1996) and after (1999) introduction of the medical emergency team. SETTING: 300 bed tertiary referral teaching hospital. PARTICIPANTS: All patients admitted to the hospital in 1996 (n=19 317) and 1999 (n=22 847). INTERVENTIONS: Medical emergency team (two doctors and one senior intensive care nurse) attended clinically unstable patients immediately with resuscitation drugs, fluid, and equipment. Response activated by the bedside nurse or doctor according to predefined criteria. MAIN OUTCOME MEASURES: Incidence and outcome of unexpected cardiac arrest. RESULTS: The incidence of unexpected cardiac arrest was 3.77 per 1000 hospital admissions (73 cases) in 1996 (before intervention) and 2.05 per 1000 admissions (47 cases) in 1999 (after intervention), with mortality being 77% (56 patients) and 55% (26 patients), respectively. After adjustment for case mix the intervention was associated with a 50% reduction in the incidence of unexpected cardiac arrest (odds ratio 0.50, 95% confidence interval 0.35 to 0.73). CONCLUSIONS: In clinically unstable inpatients early intervention by a medical emergency team significantly reduces the incidence of and mortality from unexpected cardiac arrest in hospital.

Adult↗

Impact of age on long-term survival and quality of life following out-of-hospital cardiac arrest.

OBJECTIVE: Early defibrillation programs have improved long-term outcomes following out-of-hospital cardiac arrest from ventricular fibrillation. Although long-term collective quality of life and survival are favorable, there are subsets of these patients who may be predisposed to worse outcomes. In particular, elderly patients may present with more comorbid medical conditions affecting their outcome. However, the impact of age on mortality rate and quality of life after rapid defibrillation is unknown. DESIGN: Observational study. SETTING: Hospital. SUBJECTS: All patients with an out-of-hospital cardiac arrest between November 1990 and January 2001 who received rapid defibrillation for ventricular fibrillation in Olmsted County, Minnesota. All patients received treatment at one hospital. INTERVENTIONS: Long-term outcome and quality of life were followed. Survival was estimated using the Kaplan-Meier method. The quality of life was established by an SF-36 survey. MEASUREMENTS AND MAIN RESULTS: Two hundred patients presented in ventricular fibrillation out-of-hospital cardiac arrest; of these, 138 (69%) survived to hospital admission, seven (4%) died in the emergency department, and 79 (39%) were discharged neurologically intact. The average age was 62+/-16 yrs, with 51% (n = 40) of the population > or =65. The average length of follow-up was 4.8+/-3.0 yrs. The 5-yr survival in patients <65 was 94% (confidence interval, 86-100%) and 66% (confidence interval, 52-84%) in patients > or =65 (p <.001). The observed survival in the younger group was not different from that expected in a U.S. age- and gender-matched population. However, in the older group, the expected survival was significantly lower compared with an age- and gender-matched U.S. population (p =.01) but similar to an age-, gender-, and disease-matched cohort of patients from Olmsted County not experiencing an arrest. In both age-dependent cohort populations, the quality of life scores crossed the norm in all categories with exception of vitality in patients >65 yrs old (42.6+/-7.2). In direct comparison between the two patient groups, the older cohort reported lower levels of physical functioning (p =.002), role-emotional score (p =.03), and role-physical score (p =.007). Other SF-36 scores were not different between the groups. Sixty-five percent of patients <65 yrs returned to work compared with 56% of older patients. CONCLUSIONS: The survival rate for ventricular fibrillation out-of-hospital cardiac arrest is significantly improved by the presence of a rapid defibrillation program. In patients <65 yrs old, long-term survival is equal to that of normal individuals and quality of life is similar to the general population. The survival, although high, in older patients is less than that in age-matched healthy controls, and physical and emotional quality of life scores are decreased.

Academic Medical Centers↗

Brain cortex tissue Ca, Mg, Fe, Na, and K following resuscitation from cardiac arrest in dogs.

Recent evidence suggests that ultimate neurologic injury following cardiac arrest and resuscitation may be largely determined by biochemical events occurring during reperfusion. To test this hypothesis and further characterize the time course of some of these events, we examined tissue samples from the parietal cortex for their total content of calcium (Ca), magnesium (Mg), iron (Fe), sodium (Na), and potassium (K) after 10 minutes, two hours, four hours, and eight hours of reperfusion following a 15-minute cardiac arrest in dogs. After 10 minutes of reperfusion, there were relatively small, but significant, increases in the total tissue content of Ca and Na, as compared to nonischemic controls. All values had returned to normal at two hours and remained normal at four hours of reperfusion. However, at eight hours of reperfusion, Ca and Na content approximately doubled and K content was reduced by half. There were no significant changes at any time in the tissue content of Fe or Mg. We conclude that with between four and eight hours of reperfusion following a 15-minute cardiac arrest, a major defect occurs in many cells of the cortex with respect to their ability to control ionic balances of Ca, Na, and K. This might be explained either by failure of the energy-dependent ionic pumps or by more generalized damage to the membrane permeability barrier by a process such as lipid peroxidation.

Animals↗

Time course of serum neuron-specific enolase. A predictor of neurological outcome in patients resuscitated from cardiac arrest.

BACKGROUND AND PURPOSE: The prediction of neurological outcome in comatose cardiac arrest survivors has enormous ethical and socioeconomic implications. The purpose of the present study was to investigate the prognostic relevance of the time course of serum neuron-specific enolase (NSE) as a biochemical marker of hypoxic brain damage. METHODS: Serial analysis of serum NSE levels was performed in 56 patients resuscitated from witnessed, nontraumatic, normothermic, in- or out-of-hospital cardiac arrest. The neurological outcome was evaluated with the use of the cerebral performance category (CPC) within 6 months after restoration of spontaneous circulation (ROSC). The Mann-Whitney U test was used to compare patients with good (CPC 1 to 2) and bad (CPC 3 to 4) neurological outcome. The diagnostic performance at different time points after ROSC was described in terms of areas under receiver operating characteristic curves according to standard methods. RESULTS: Patients with a bad neurological outcome (CPC 3 to 4) had significantly higher NSE levels than those with a good neurological outcome at 12 (P=0.004), 24 (P=0.04), 48 (P<0.001), and 72 hours (P<0.001) after ROSC. The maximum NSE level measured within 72 hours after ROSC was also significantly higher in patients with a bad neurological outcome (P<0.001). The NSE value at 72 hours after ROSC was the best predictor of neurological outcome (area under the curve=0.92+/-0.04). In addition, we also found a significant difference in the time course of NSE concentrations during the first 3 days after ROSC. CONCLUSIONS: Serum NSE levels are valuable adjunctive parameters for assessing neurological outcome after cardiac arrest.

Adolescent↗

Successful automatic external defibrillator operation by people trained only in basic life support in a simulated cardiac arrest situation.

OBJECTIVE: To show whether in an in-hospital cardiac arrest, early defibrillation can also be performed by hospital staff trained only in basic life support. BACKGROUND: The International Liaison Committee on Resuscitation (ILCOR) endorses the concept that in many settings non-medical individuals should be allowed and encouraged to use defibrillators. METHODS: Five different groups of hospital staff were evaluated whether they were able to correctly operate an automatic external defibrillator in a simulated sudden cardiac arrest situation without any prior instruction. The participants were assigned either to the 'basic life support-trained' group (BLS, n = 40, or to the 'advanced life support-trained' group (ALS, n = 40). RESULTS: All persons of the 'only BLS-trained' group delivered the three sequential ('stacked') shocks with the automatic external defibrillator when persistent ventricular fibrillation was simulated. The 'ALS-trained' persons successfully delivered the three shocks with the automatic external defibrillator in 98% of the cases. When this group used a conventional defibrillator, only 88% were able to deliver the three shocks, however they were able to do it significantly more quickly. CONCLUSION: Using an automatic defibrillator without any prior instruction, even persons trained only in BLS were able to deliver three sequential shocks in a simulated persistent ventricular fibrillation cardiac arrest.

Adult↗

Cardiopulmonary resuscitation of adults in the hospital: a report of 14720 cardiac arrests from the National Registry of Cardiopulmonary Resuscitation.

The National Registry of Cardiopulmonary Resuscitation (NRCPR) is an American Heart Association (AHA)-sponsored, prospective, multisite, observational study of in-hospital resuscitation. The NRCPR is currently the largest registry of its kind. The purpose of this article is to describe the NRCPR and to provide the first comprehensive, Utstein-based, standardized characterization of in-hospital resuscitation in the United States. All adult (>/=18 years of age) and pediatric (<18 years of age) patients, visitors, employees, and staff within a facility (including ambulatory care areas) who experience a resuscitation event are eligible for inclusion in the NRCPR database. Between January 1, 2000, and June 30, 2002, 14720 cardiac arrests that met inclusion criteria occurred in adults at the 207 participating hospitals. An organized emergency team is available 24 h a day, 7 days a week in 86% of participating institutions. The three most common reasons for cardiac arrest in adults were (1) cardiac arrhythmia, (2) acute respiratory insufficiency, and (3) hypotension. Overall, 44% of adult in-hospital cardiac arrest victims had a return of spontaneous circulation (ROSC); 17% survived to hospital discharge. Despite the fact that a primary arrhythmia was one of the precipitating events in nearly one half of adult cardiac arrests, ventricular fibrillation (VF) was the initial pulseless rhythm in only 16% of in-hospital cardiac arrest victims. ROSC occurred in 58% of VF cases, yielding a survival-to-hospital discharge rate of 34% in this subset of patients. An automated external defibrillator was used to provide initial defibrillation in only 1.4% of patients whose initial cardiac arrest rhythm was VF. Neurological outcome in discharged survivors was generally good. Eighty-six percent of patients with Cerebral Performance Category-1 (CPC-1) at the time of hospital admission had a postarrest CPC-1 at the time of hospital discharge.

Adolescent↗

Augmentation of ventricular preload during treatment of cardiovascular collapse and cardiac arrest.

Despite aggressive measures for the treatment of cardiovascular collapse and cardiac arrest, the hypotension associated with these malignant processes usually leads to profound vital-organ ischemia and death. A fundamental therapeutic challenge of such life-threatening processes is the restoration of adequate blood flow to the heart and the brain. However, to maintain adequate forward blood flow out of the heart, venous blood return must be drawn back into the heart. With the exception of administration of exogenous fluid replacement, there are limited ways to enhance blood flow back to the heart during prolonged hypotension. This article describes the potential value of a new impedance threshold valve for the treatment of cardiac arrest and hypotension. The valve was designed to create a vacuum within the thorax during the decompression phase of cardiopulmonary resuscitation or during inhalation. By transiently blocking inspiratory gas exchange during the decompression phase of cardiopulmonary resuscitation, after phrenic nerve-stimulated gasping, or during spontaneous ventilation, the impedance-valve concept may have clinical value in the treatment of patients in cardiac arrest, hemorrhagic shock, and cardiovascular collapse secondary to a number of life-threatening clinical processes.

Animals↗

Thrombolytic therapy after cardiac arrest and its effect on neurological outcome.

OBJECTIVE: the aim of the study is to investigate the effect of thrombolytic therapy on neurological outcome in patients after cardiac arrest due to acute myocardial infarction. Laboratory investigations have demonstrated that thrombolytic therapy after cardiopulmonary resuscitation improves neurological function. METHODS: from July 1991 to June 1996, patients with witnessed ventricular fibrillation cardiac arrest due to acute MI and successful restoration of spontaneous circulation admitted to the emergency department were analyzed retrospectively. A logistic regression model was used to assess the association between thrombolytic therapy and neurological outcome [best cerebral performance category (CPC) within 6 months after cardiac arrest]. RESULTS: all 157 patients [median age 57 years (IQR 50-69)] were analyzed. Thrombolytic therapy was applied in 42 patients (27%). With thrombolytic therapy good functional neurological recovery (CPC 1 or 2) was achieved more frequently (69 vs. 50%, P=0.03). After controlling for age, prehospital dosage of epinephrine, and the duration of cardiac arrest we found a non significant trend towards good neurological recovery when thrombolytic therapy was given (OR 1.9, 95% CI 0.8-4.6). CONCLUSION: thrombolytic therapy after cardiac arrest due to acute myocardial infarction is associated with improved neurological outcome.

Aged↗

A comparison of repeated high doses and repeated standard doses of epinephrine for cardiac arrest outside the hospital. European Epinephrine Study Group.

BACKGROUND: Clinical trials have not shown a benefit of high doses of epinephrine in the management of cardiac arrest. We conducted a prospective, multicenter, randomized study comparing repeated high doses of epinephrine with repeated standard doses in cases of out-of-hospital cardiac arrest. METHODS: Adult patients who had cardiac arrest outside the hospital were enrolled if the cardiac rhythm continued to be ventricular fibrillation despite the administration of external electrical shocks, or if they had asystole or pulseless electrical activity at the time epinephrine was administered. We randomly assigned 3327 patients to receive up to 15 high doses (5 mg each) or standard doses (1 mg each) of epinephrine according to the current protocol for advanced cardiac life support. RESULTS: In the high-dose group, 40.4 percent of 1677 patients had a return of spontaneous circulation, as compared with 36.4 percent of 1650 patients in the standard-dose group (P=0.02); 26.5 percent of the patients in the high-dose group and 23.6 percent of those in the standard-dose group survived to be admitted to the hospital (P=0.05); 2.3 percent of the patients in the high-dose group and 2.8 percent in the standard-dose group survived to be discharged from the hospital (P=0.34). There was no significant difference in neurologic status according to treatment among those discharged. High-dose epinephrine improved the rate of successful resuscitation in patients with asystole, but not in those with ventricular fibrillation. CONCLUSIONS: In our study, long-term survival after cardiac arrest outside the hospital was no better with repeated high doses of epinephrine than with repeated standard doses.

Adrenergic Agonists↗

Structural protection of the myocardial capillary endothelium by different forms of cardiac arrest and subsequent global ischemia at 5 degrees C.

BACKGROUND: In transplantation surgery sufficient myocardial protection achieved by cardioplegic cardiac arrest and deep hypothermia is a prerequisite for successful resumption of donor heart function. Intraischemic damage of the endothelium combined with capillary compression may lead to the "no-reflow phenomenon" during reperfusion, resulting in insufficient cardiac resuscibility. METHODS: We evaluated the endothelial ultrastructure after various common forms of cardiac arrest and subsequent ischemia in deep hypothermia. Canine hearts were arrested by aortic cross clamping and surface cooling with Tutofusin' (ACC) or by coronary perfusion with Custodiol (histidine tryptophane ketoglutarate, HTK solution), with University of Wisconsin solution (UW), or with St. Thomas' Hospital solution. After extirpation the hearts were incubated at 5 degrees C in the solution used for cardiac arrest. Myocardial samples were taken immediately after cardiac arrest and after 2h, 4h, 6h, and 10 h of global ischemia. The degree of structural damage was evaluated by a scoring system. Endothelial swelling was determined as the mean barrier thickness of the capillary endothelium. RESULTS: At all selected time points our results show that 1) after cardioplegia with St. Thomas' solution, the degree of endothelial cell swelling was higher than after aortic cross clamping; 2) using HTK or UW solution, the endothelial ultrastructure was better preserved than after aortic cross clamping or using St. Thomas' solution, whereby HTK was slightly better than UW; 3) using UW solution, endothelial cell swelling was a little (up to 10%) but significantly less than after HTK perfusion. CONCLUSIONS: With respect to the intraischemic structural preservation of endothelial cells, UW or HTK solution combined with deep hypothermia promises adequate protection, compared with other clinically used methods tested.

Animals↗

A comparison of antecedents to cardiac arrests, deaths and emergency intensive care admissions in Australia and New Zealand, and the United Kingdom--the ACADEMIA study.

Many patients have physiological deterioration prior to cardiac arrest, death and intensive care unit (ICU) admission, that are detected and documented by medical and nursing staff. Appropriate early response to detected deterioration is likely to benefit patients. In a multi-centre, prospective, observational study over three consecutive days, we studied the incidence of antecedents (serious physiological abnormalities) preceding primary events (defined as in-hospital deaths, cardiac arrests, and unanticipated ICU admissions) in 90 hospitals (69 United Kingdom [UK]; 19 Australia and 2 New Zealand [ANZ]). 68 hospitals reported primary events during the three-day study period (50 United Kingdom, 16 Australia and 2 New Zealand). Data on the availability of ICU/HDU beds and cardiac arrest teams and Medical Emergency Teams were also collected. Of 638 primary events, there were 308 (48.3%) deaths, 141 (22.1%) cardiac arrests, and 189 (29.6%) unplanned ICU admissions. There were differences in the pattern of primary events between the UK and ANZ (P < 0.001). There were proportionally more deaths in the UK (52.3% versus 35.3%) and a higher number of unplanned ICU admissions in ANZ (47.3% versus 24.2%). Sixty percent (383) of primary events had a total of 1032 documented antecedents. The most common antecedents were hypotension and a fall in Glasgow Coma Scale. The proportion of ICU/HDU to general hospital beds was greater in ANZ (0.034 versus 0.016, P < 0.001) and medical emergency teams were more common in ANZ (70.0% versus 27.5%, P = 0.001). The data confirm antecedents are common before death, cardiac arrest, and unanticipated ICU admission. The study also shows differences in patterns of primary events, the provision of ICU/HDU beds and resuscitation teams, between the UK and ANZ. Future research, focusing upon the relationship between service provision and the pattern of primary events, is suggested.

Adolescent↗

Acute physiology and chronic health evaluation (APACHE II) and Glasgow coma scores as predictors of outcome from intensive care after cardiac arrest.

OBJECTIVES: a) To examine the accuracy of the Acute Physiology and Chronic Health Evaluation (APACHE II) and the Glasgow Coma Scores as predictors of the outcome of patients following resuscitation from cardiac arrest; b) to study the impact of the components of APACHE II on the prediction. DESIGN: A nationwide study in Finland with prospectively collected data on all patients admitted to intensive care after cardiac arrest during a 14-month period. Two thirds of the cardiac arrest patients included in the study were randomly selected to derive predictive models, and the remaining one third constituted the validation sample. SETTING: A total of 25 medical and surgical ICUs in Finland (13 in tertiary referral centers). PATIENTS: Six-hundred nineteen consecutive cardiac arrest patients. Fifteen patients less than 16 yrs were excluded. MAIN OUTCOME MEASURES: Variables included in the APACHE II or Glasgow Coma Scores were collected at the time of ICU admission and then three times after admission, at 24-hr intervals. ICU- and hospital-mortality rates and a 6-month mortality rate after ICU admission were studied. RESULTS: Of 604 study patients, 370 (61.3%) patients died in the hospital. The most accurate prediction of hospital outcome was based on data collected after the first day of ICU care, not on the admission values. Twenty-one (21.9%) of 96 patients with a low APACHE II score (less than or equal to 9) died compared with 66 (84.6%) of 78 patients with a high APACHE II score (greater than or equal to 25) (p less than .001). Of 160 patients with a normal Glasgow Coma Score (14 to 15), 45 (28.1%) died, whereas there were 114 (81.4%) nonsurvivors among 140 patients with a low Glasgow Coma Score of 3 (p less than .001). The performance of predictive models, including age, the Chronic Health Evaluation, and either the Acute Physiology Score (Acute Physiology Score model) or the Glasgow Coma Score (Glasgow Coma Score model) were compared with the prediction according to the APACHE II in the validation sample. When using 80% probability of death as a decision rule, the Acute Physiology Score model determined 35 of 153 patients to have high risk of death, 29 of whom died (the positive predictive value being 82.9%). The Glasgow Coma Score model predicted 34 patients to die, 26 of whom died (positive predictive value 76.5%), and the APACHE II score predicted seven deaths, five of whom actually died (positive predictive value 71.4%). CONCLUSIONS: The APACHE II scoring system cannot be recommended as a prognostic tool to support clinical judgement in cardiac arrest patients, but by modifying it, a more accurate prediction of poor outcome could be achieved. The Glasgow Coma Score explained to a great extent the predictive power of the APACHE II.

Adult↗

Circadian variation in witnessed out of hospital cardiac arrest.

OBJECTIVES: To examine the effect on circadian variation of out of hospital cardiac arrest according to the underlying aetiology and presenting rhythm of arrest, and to explore strategies that might help to improve survival outcome using circadian variation. DESIGN: Population based retrospective study. SETTING: County of Nottinghamshire with a total population of 993 914 and an area of 2183 km(2). SUBJECTS: Between 1 January 1991 and 3 December 1994, all witnessed cardiac arrests attended by the Nottinghamshire Ambulance Service, of which 1196 patients had a cardiac cause for their arrest (ICD, 9th revision, codes 390-414 and 420-429) and 339 had a non-cardiac cause. RESULTS: The circadian variation of the cardiac cases was not significantly different from that of non-cardiac cases (p = 0.587), even when adjusted for age, sex, or presenting rhythm of arrest. For cardiac cases, the circadian variation of those who presented with ventricular fibrillation was significantly different from those presenting with a rhythm other than ventricular fibrillation (p = 0.005), but was similar to the circadian variation of bystander cardiopulmonary resuscitation (p = 0.306) and survivors (p = 0.542). Ambulance response time was also found to have a circadian variation. CONCLUSIONS: There is a common circadian variation of out of hospital cardiac arrest, irrespective of underlying aetiology, where the presenting rhythm is other than ventricular fibrillation. This is different from the circadian variation of cases of cardiac aetiology presenting with ventricular fibrillation. The circadian variation of ventricular fibrillation, and consequently survival, may be affected by the availability of bystander cardiopulmonary resuscitation and the speed of ambulance response.

Aged↗

Cerebral vasoconstriction in comatose patients resuscitated from a cardiac arrest?

OBJECTIVE: To determine the role of cerebral vasoconstriction in the delayed hypoperfusion phase in comatose patients after cardiac arrest. DESIGN: Prospective study. SETTING: Medical intensive care unit in a university hospital. PATIENTS: 10 comatose patients (Glasgow Coma Score +/- 6)successfully resuscitated from a cardiac arrest occurring outside the hospital. MEASUREMENTS: We measured the pulsatility index (PI) and mean blood flow velocity (MFV) of the middle cerebral artery, the cerebral oxygen extraction ratio and jugular bulb levels of endothelin, nitrate, and cGMP during the first 24 h after cardiac arrest. RESULTS: The PI decreased significantly from 1.86 +/- 1.02 to 1.05 +/- 0.22 (p = 0.03). The MFV increased significantly from 29 +/- 10 to 62 +/- 25 cm/s (p = 0.003). Cerebral oxygen extraction ratio decreased also from 0.39 +/- 0.13 to 0.24 +/- 0.11 (p = 0.015). Endothelin levels were high but did not change during the study period. Nitrate levels varied widely and showed a slight but significant decrease from 37.1 mumol/l (median; 25th-75th percentiles: 26.8-61.6) to 31.3 mumol/l (22.1-39.6) (p = 0.04). Cyclic guanosine monophosphate levels increased significantly from 2.95 mumol/l (median; 25th-75th percentiles: 2.48-5.43) to 7.5 mumol/l (6.20-14.0) (p = 0.02). CONCLUSIONS: We found evidence of increased cerebrovascular resistance during the first 24 h after cardiac arrest with persistent high endothelin levels, gradually decreasing nitrate levels, and gradually increasing cGMP levels, This suggests that active cerebral vasoconstriction due to an imbalance between local vasodilators and vasoconstrictors plays a role in the delayed hypoperfusion phase.

Adult↗

Sodium bicarbonate may improve outcome in dogs with brief or prolonged cardiac arrest.

OBJECTIVE: Despite the absence of outcome evaluation, the use of sodium bicarbonate in cardiac arrest has declined based on advanced cardiac life-support guidelines. The effects of bicarbonate therapy on outcome in a canine model of ventricular fibrillation cardiac arrest of brief (5-min) and prolonged (15-min) duration were examined. DESIGN: Prospective, randomized, controlled trial. SETTING: Experimental animal laboratory in a university medical center. SUBJECTS: Thirty-two adult dogs, weighing 10 to 17 kg. INTERVENTIONS: The animals were prepared with ketamine, nitrous oxide/oxygen, halothane, and pancuronium. Ventricular fibrillation was then electrically induced and maintained in arrest for 5 mins (n = 12) or 15 mins (n = 20). Canine advanced cardiac life-support protocols were instituted, including defibrillation, cardiopulmonary resuscitation (CPR), and the administration of epinephrine (0.1 mg/kg), atropine, and lidocaine. The bicarbonate group received 1 mmol/kg of sodium bicarbonate initially, and base deficit was corrected to -5 mmol/L with additional bicarbonate, whereas acidemia was untreated in the control group. Cardiopulmonary values were recorded at intervals between 5 mins and 24 hrs, and the neurologic deficit score was determined at 24 hrs after CPR. MEASUREMENTS AND MAIN RESULTS: The treatment group received an additional 2 to 3 mmol/kg of bicarbonate in the early postresuscitation phase. Compared with controls, the bicarbonate group demonstrated equivalent (with brief arrest) or improved (with prolonged arrest) return of spontaneous circulation and survival to 24 hrs, with lessened neurologic deficit. The acidosis of arrest was decreased in the prolonged arrest group without hypercarbia. Improved coronary and systemic perfusion pressures were noted in the bicarbonate group with prolonged arrest, and the epinephrine requirement for return of spontaneous circulation was decreased. CONCLUSIONS: The empirical administration of bicarbonate improves the survival rate and neurologic outcome in a canine model of cardiac arrest.

Acidosis↗

Effect of moderate hypothermia on lipid peroxidation in canine brain tissue after cardiac arrest and resuscitation.

BACKGROUND AND PURPOSE: We sought to examine the effect of moderate hypothermia (30 degrees C to 32 degrees C) initiated after resuscitation on the scavenging systems of free radicals and lipid peroxidation in canine brain tissue after cardiac arrest and resuscitation. METHODS: Twenty-one dogs were divided into four groups: group A, nonischemic controls (shams) (n = 4); group B, 15-minute cardiac arrest without reperfusion (n = 4); group C, 15-minute cardiac arrest and standard resuscitation (n = 6); and group D, 15-minute cardiac arrest and hypothermic resuscitation (n = 7). During the period of 10 to 120 minutes after resuscitation, brain temperature and core temperature in group D remained at 30 degrees C to 32 degrees C and were 4 degrees C to 5 degrees C lower than in group C. For each dog, a sample of right parietal cerebral cortex was obtained from group A, group B, or from group C and group D at 2 hours after resuscitation. The sample was assayed for tissue malondialdehyde (MDA), the content of reduced glutathione (GSH), and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX). RESULTS: In group B, a 15-minute cardiac arrest induced an increase in MDA, a significant reduction of GSH, and no change in SOD and GSH-PX activities compared with group A. In group C, there were further increases in MDA and reductions in GSH content and GSH-PX activity compared with group A; SOD activity remained substantially unchanged. The content of MDA was higher in group D than in group A but less elevated in group D than in group C. The GSH content and SOD and GSH-PX activities were significantly higher in group D than in group C. CONCLUSIONS: Moderate hypothermia initiated after resuscitation can significantly inhibit the accumulation of lipid peroxidation products and the consumption of free radical scavengers in the brain tissue.

Animals↗

[Attitude of general practitioners to treatment of their own cardiac arrests occurring outside hospital].

By means of an anonymous investigation, all 375 general practitioners in the County of Arhus were questioned about their attitudes to treatment of cardiac arrest occurring in themselves outside hospital. Treatment is undertaken in a heart ambulance (with DC-equipment but without qualified medical staff). In addition, they were questioned about therapeutic wishes if primary resuscitation with ventilation and cardiac massage were administered by a layman. The same question was repeated after the practitioners had read an up-to-date article about the results of treatment of cardiac arrest outside hospital. Finally, the practitioners were asked whether they consider that the remainder of the population should be treated as they wished. 81% of the practitioners replied to the questionnaires. The results are presented in tabular form. Reading of the article altered the replies given by the practitioners only to a limited extent. After reading of the article, 79.7% did not wish resuscitation if the total time interval from cardiac arrest to commencement of treatment by the ambulance staff was six minutes or more. This is significantly less than the average time interval in cases of ambulance turn out on account of cardiac arrest. Should the primary resuscitation be administered by a layman, 66.8% do not wish resuscitation by the ambulance staff in the same situation. 82.8% of the practitioners agreed that the population as a whole should have the same populations as themselves. 6.4% disagreed. On the basis of these results possible alterations in the current treatment for cardiac arrest outside hospital are discussed.

Adult↗

Imaging of the apparent diffusion coefficient for the evaluation of cerebral metabolic recovery after cardiac arrest.

The apparent diffusion coefficient (ADC) of water is a sensitive indicator of water and ion homeostasis of brain. Resuscitation of the brain after cardiac arrest, the most frequent reason for global cerebral ischemia under clinical conditions, depends critically on the reversal of disturbances of water and ion homeostasis. We, therefore, investigated whether ADC imaging can be used to monitor the development and reversal of ischemic brain injury during and after cardiac arrest. Ten adult mongrel normothermic cats were anesthetized with alfentanil and midazolam, immobilized with pancuronium, and mechanically ventilated with O2/N2O. Arterial, left ventricular, central venous, and intracranial pressures were monitored throughout the experiment. Magnetic resonance imaging was performed in a 4.7T MR scanner with a shielded gradient system. Diffusion-weighted images (DWI) were obtained by pulsed gradient spin echoes (diffusion weighting factor b: 0, 500, 1000, 1500 s/mm2). Quantitative ADC images were calculated from DWIs by fitting signal intensities against b-factors. Fifteen minute cardiac arrest was induced in the magnet by electrical fibrillation. Resuscitation was also carried out in the magnet, using a pneumatic vest for remotely controlled closed chest cardiac massage. Seven of 10 animals were resuscitated successfully and subsequently monitored for 3 h. During cardiac arrest, ADC declined from 678 +/- 79 x 10(-6) to 430 +/- 128 x 10(-6) mm2/s (63% of baseline). In the successfully resuscitated animals ADC returned to 648 +/- 108 x 10(-6) mm2/s within 30 min and remained at this level throughout the 3 h of recirculation. Regional evaluations of ADC revealed a transient overshoot in brainstem and basal ganglia to 114% of control at 15 min before returning to baseline values after 40 min. Failure of cardiac resuscitation prevented ADC normalization and led to its further decline to below 50% of control. Postcardiac arrest normalization of ADC maps correlated with homogeneous return of ATP, glucose, and lactate to near normal, whereas failure of ADC normalization was associated with depletion of ATP and glucose and severe lactate accumulation. In conclusion, our data indicate, that normalization of ADC is a reliable indicator of cerebral recovery after resuscitation from cardiac arrest.

Animals↗