Rudolph W. Koster

Global incidences of out-of-hospital cardiac arrest and survival rates: Systematic review of 67 prospective studies ,

AIMnThe aim of this investigation was to estimate and contrast the global incidence and outcome of out-of-hospital cardiac arrest (OHCA) to provide a better understanding of the variability in risk and survival of OHCA.nnnMETHODSnWe conducted a review of published English-language articles about incidence of OHCA, available through MEDLINE and EmBase. For studies including adult patients and both adult and paediatric patients, we used Utstein data reporting guidelines to calculate, summarize and compare incidences per 100,000 person-years of attended OHCAs, treated OHCAs, treated OHCAs with a cardiac cause, treated OHCA with ventricular fibrillation (VF), and survival-to-hospital discharge rates following OHCA.nnnRESULTSnSixty-seven studies from Europe, North America, Asia or Australia met inclusion criteria. The weighted incidence estimate was significantly higher in studies including adults than in those including adults and paediatrics for treated OHCAs (62.3 vs 34.7; P<0.001); and for treated OHCAs with a cardiac cause (54.6 vs 40.8; P=0.004). Neither survival to discharge rates nor VF survival to discharge rates differed statistically significant among studies. The incidence of treated OHCAs was higher in North America (54.6) than in Europe (35.0), Asia (28.3), and Australia (44.0) (P<0.001). In Asia, the percentage of VF and survival to discharge rates were lower (11% and 2%, respectively) than those in Europe (35% and 9%, respectively), North America (28% and 6%, respectively), or Australia (40% and 11%, respectively) (P<0.001, P<0.001).nnnCONCLUSIONSnOHCA incidence and outcome varies greatly around the globe. A better understanding of the variability is fundamental to improving OHCA prevention and resuscitation.

Value of Myoglobin, Troponin T, and CK-MBmass in Ruling Out an Acute Myocardial Infarction in the Emergency Room

BACKGROUNDnRuling out acute myocardial infarction (AMI) on the basis of rapid assays for cardiac markers will allow early triage of patients and cost-effective use of available coronary care facilities.nnnMETHODS AND RESULTSnWe studied the value of myoglobin, creatine kinase (CK)-MBmass, and troponin T in ruling out an AMI in the emergency room in 309 consecutive patients presenting with chest pain. The gold standard for AMI was the combination of history, ECG, and a typical curve of the CK-MB activity (CK-MBact). Myoglobin was the earliest marker, and its negative predictive value (NPV) was significantly higher than for CK-MBmass and troponin T from 3 to 6 hours after the onset of symptoms (myoglobin versus CK-MBmass, P < .03; myoglobin versus troponin T, P < .01). The NPV of myoglobin reached 89% 4 hours after the onset of symptoms. The NPV of CK-MBmass reached 95% 7 hours after the onset of symptoms. Troponin T was not an early marker for ruling out AMI, and NPV changed over time, together with CK-MBact. The early NPV was higher in a subgroup of patients with a low probability of the presence of AMI for the three markers. Cardiac markers rise earlier in patients with large infarcts than in patients with small infarcts as indicated by the cumulative proportion of the marker above the upper reference limit at each time point (myoglobin, P = .04; CK-MBmass, P = .013; troponin T, P = .016).nnnCONCLUSIONSnFor ruling out AMI in the emergency room, myoglobin is a better marker than CK-MBmass or troponin T from 3 until 6 hours after the onset of symptoms, but the maximal NPV reaches only 89%. At 7 hours, the NPV of CK-MBmass is 95%. The test characteristics are influenced by the probability of the presence of AMI in the patients studied and by the size of their AMI. Infarct size of AMI patients should be reported in studies evaluating cardiac markers.

Bystander initiated actions in out-of-hospital cardiopulmonary resuscitation: results from the Amsterdam Resuscitation Study (ARRESUST)

The objective of this study was to analyze the functioning of the first two links of the chain of survival: access and basic cardiopulmonary resuscitation (CPR). In a prospective study, all bystander witnessed circulatory arrests resuscitated by emergency medical service (EMS) personnel, were recorded consecutively. Univariate differences in survival were calculated for various witnesses, the performance of basic CPR, the quality of CPR, the performers of CPR and the delays. A logistic regression model for survival was developed from all potential predictors of these first two links. From the 922 included patients, 93 survived to hospital discharge. In 21% of the cases, the witness did not immediately call 112, but first called others, resulting in a longer delay and a lower survival. Family members were frequent witnesses of the arrest (44%), but seldom started basic CPR (11%). Survival, when basic CPR performers were untrained and had no previous experience, was similar to that when no basic CPR was performed (6%). Not performing basic CPR, delay in basic CPR, the interval between basic CPR and EMS arrival, and being both untrained and inexperienced in basic CPR were independent predictors for survival. Basic CPR performed by persons trained a long time ago did not appear to have a negative influence on outcome, nor did basic CPR limited to chest compressions alone. The mere reporting that basic CPR has been performed does not describe adequately the actual value of basic CPR. The interval from collapse to initiation of basic CPR, and the training and experience of the performer must be taken into account. Policy makers for basic CPR training should focus on partners of the patients, who are most likely witness of an arrest.

Out-of-hospital cardiac arrests in Amsterdam and its surrounding areas: results from the Amsterdam resuscitation study (ARREST) in Utstein style.

The purpose of this study was to describe the chain of survival in Amsterdam and its surroundings and to suggest areas for improvement. To ensure accurate data, collection was made by research personnel during the resuscitation, according to the Utstein recommendations. Between June 1, 1995 and August 1, 1997 all consecutive cardiac arrests were registered. Patient characteristics, resuscitation characteristics and time intervals were analyzed in relation to survival. From the 1046 arrests with a cardiac etiology and where resuscitation was attempted, 918 cases were not witnessed by EMS personnel. The analysis focussed on these 918 patients of whom 686 (75%) died during resuscitation, 148 (16%) died during hospital admission and 84 patients (9%) survived to hospital discharge. Patient and resuscitation characteristics associated with survival were: age, VF as initial rhythm, witnessed arrest and bystander CPR. EMS arrival time was significantly shorter for survivors (median 9 min) compared to non-survivors (median 11 min). In 151 cases the police was also alerted and arrived 5 min (median) earlier than EMS personnel. Using the OPC/CPC good functional health was observed in 50% of the survivors and moderate performance in 29%. All links in the chain of survival must be strengthened, but equipping the police with semi-automatic defibrillators may be the most useful intervention to improve survival.

Importance of the First Link Description and Recognition of an Out-of-Hospital Cardiac Arrest in an Emergency Call

Background— The content of emergency calls for suspected cardiac arrest is rarely analyzed. This study investigated the recognition of a cardiac arrest by dispatchers and its influence on survival rates. Methods and Results— During 8 months, voice recordings of 14 800 consecutive emergency calls were collected to audit content and cardiac arrest recognition. The presence of cardiac arrest during the call was assessed from the ambulance crew report. Included calls were placed by laypersons on site and did not involve trauma. Prevalence of cardiac arrest was 3.0%. Of the 285 cardiac arrests, 82 (29%) were not recognized during the call, and 64 of 267 suspected calls (24%) were not cardiac arrest. We analyzed a random sample (n=506) of 9230 control calls. Three-month survival was 5% when a cardiac arrest was not recognized versus 14% when it was recognized (P=0.04). If the dispatcher did not recognize the cardiac arrest, the ambulance was dispatched a mean of 0.94 minute later (P<0.001) and arrived 1.40 minutes later on scene (P=0.01) compared with recognized calls. The main reason for not recognizing the cardiac arrest was not asking if the patient was breathing (42 of 82) and not asking to describe the type of breathing (16 of 82). Normal breathing was never mentioned in true cardiac arrest calls. A logistic regression model identified spontaneous trigger words like facial color that could contribute to cardiac arrest recognition (odds ratio, 7.8 to 9.7). Conclusions— Not recognizing a cardiac arrest during emergency calls decreases survival. Spontaneous words that the caller uses to describe the patient may aid in faster and better recognition of a cardiac arrest.

Survival models for out-of-hospital cardiopulmonary resuscitation from the perspectives of the bystander, the first responder, and the paramedic

Survival from out-of-hospital resuscitation depends on the strength of each component of the chain of survival. We studied, on the scene, witnessed, nontraumatic resuscitations of patients older than 17 years. The influence of the chain of survival and potential predictors on survival was analyzed by logistic regression modeling. From 1030 patients, 139 survived to hospital discharge. Three prediction models of survival were developed from the perspective of the different contributors active in out-of-hospital resuscitation: model I, bystanders; model II, first responders; and model III, paramedics. Predictors for survival (with odds ratio) were: in model I (bystanders): emergency medical service (EMS) witnessed arrest (0.50), delay to basic cardiopulmonary resuscitation (CPR) (0.74/min) and delay to EMS arrival (0.87/min); in model II (first responders): initial recorded heart rhythm (0.02 for nonshockable rhythm), delay to basic CPR (0.71/min and 0.87/min for shockable and nonshockable rhythms) and to defibrillation (0.89/min), and in model III (paramedics): need for advanced CPR (4.74 for advanced CPR not-needed), initial recorded heart rhythm (0.05 for nonshockable rhythm), and delay to basic CPR (0.77/min and 0.72/min for shockable and nonshockable rhythms), to defibrillation and to advanced CPR for shockable rhythms (0.85/min), and to advanced CPR for nonshockable rhythm (0.85/min). The area under the receiver-operator characteristic curve for model I was 0.763, for model II was 0.848, and for model III was 0.896. Of survivors, 50% had restoration of circulation without need for advanced CPR. Three survival models for witnessed nontraumatic out-of-hospital resuscitation based on the information known by bystanders, first responders and paramedics explained survival with increasing precision. Early defibrillation can restore circulation without the need for advanced CPR. When advanced CPR is needed, its delay leads to a markedly reduced survival.

Impact of Onsite or Dispatched Automated External Defibrillator Use on Survival After Out-of-Hospital Cardiac Arrest

Background— There have been few studies on the effectiveness of bystander automated external defibrillator (AED) use in out-of-hospital cardiac arrest. The objective of this study was to determine whether actual use of onsite or dispatched AED reduces the time to first shock compared with no AED use and thereby improves survival. Methods and Results— We performed a population-based cohort study of 2833 consecutive patients with a nontraumatic out-of-hospital cardiac arrest before emergency medical system arrival between 2006 and 2009. The primary outcome, neurologically intact survival to discharge, was compared by use of multivariable logistic regression analysis. An onsite AED had been applied in 128 of the 2833 cases, a dispatched AED in 478, and no AED in 2227. Onsite AED use reduced the time to first shock from 11 to 4.1 minute. Neurologically intact survival was 49.6% for patients treated with an onsite AED compared with 14.3% without an AED (unadjusted odds ratio, 5.63; 95% confidence interval, 3.91–8.10). The odds ratio remained statistically significant after adjustment for confounding (odds ratio, 2.72; 95% confidence interval, 1.77–4.18). Dispatched AED use reduced the time from call to first shock to 8.5 minutes. Neurologically intact survival was 17.2% for patients treated with a dispatched AED (unadjusted odds ratio, 1.07; 95% confidence interval, 0.82–1.39). Every year, onsite AEDs saved 3.6 lives per 1 million inhabitants; dispatched AEDs saved 1.2 lives. Conclusions— The use of an onsite AED leads to a doubling of neurologically intact survival. In our system, the survival benefit of dispatched AED use was much smaller than that of onsite AED use.

Improved Survival After Out-of-Hospital Cardiac Arrest and Use of Automated External Defibrillators

Background— In recent years, a wider use of automated external defibrillators (AEDs) to treat out-of-hospital cardiac arrest was advocated in The Netherlands. We aimed to establish whether survival with favorable neurologic outcome after out-of-hospital cardiac arrest has significantly increased, and, if so, whether this is attributable to AED use. Methods and Results— We performed a population-based cohort study, including patients with out-of-hospital cardiac arrest from cardiac causes between 2006 and 2012, excluding emergency medical service–witnessed arrests. We determined survival status at each stage (to emergency department, to admission, and to discharge) and examined temporal trends using logistic regression analysis with year of resuscitation as an independent variable. By adding each covariable subsequently to the regression model, we investigated their impact on the odds ratio of year of resuscitation. Analyses were performed according to initial rhythm (shockable versus nonshockable) and AED use. Rates of survival with favorable neurologic outcome after out-of-hospital cardiac arrest increased significantly (N=6133, 16.2% to 19.7%; P for trend=0.021), although solely in patients presenting with a shockable initial rhythm (N=2823; 29.1% to 41.4%; P for trend<0.001). In this group, survival increased at each stage but was strongest in the prehospital phase (odds ratio, 1.11 [95% CI, 1.06–1.16]). Rates of AED use almost tripled during the study period (21.4% to 59.3%; P for trend <0.001), thereby decreasing time from emergency call to defibrillation-device connection (median, 9.9 to 8.0 minutes; P<0.001). AED use statistically explained increased survival with favorable neurologic outcome by decreasing the odds ratio of year of resuscitation to a nonsignificant 1.04. Conclusions— Increased AED use is associated with increased survival in patients with a shockable initial rhythm. We recommend continuous efforts to introduce or extend AED programs.

Quinidine-induced ventricular flutter and fibrillation without digitalis therapy

Three cases are described with documented ventricular flutter and fibrillation during quinidine medication without concomitant digitalis therapy. In all three patients the arrhythmia developed while they were receiving moderate doses of quinidine. Although no changes in QRS width were observed after administration of quinidine, there was marked prolongation of the Q-T interval. The mechanism of development of ventricular flutter and fibrillation in patients taking quinidine may be similar to that in patients with the Q-T prolongation syndrome.

Incidence, Causes, and Outcomes of Out-of-Hospital Cardiac Arrest in Children: A Comprehensive, Prospective, Population-Based Study in the Netherlands

OBJECTIVESnThis study sought to determine comprehensively the incidence of pediatric out-of-hospital cardiac arrest (OHCA) and its contribution to total pediatric mortality, the causes of pediatric OHCA, and the outcome of resuscitation of pediatric OHCA patients.nnnBACKGROUNDnThere is a paucity of complete studies on incidence, causes, and outcomes of pediatric OHCA.nnnMETHODSnIn this prospective, population-based study, OHCA victims younger than age 21 years in 1 province of the Netherlands were registered through both emergency medical services and coroners over a period of 4.3 years. Death certificate data on total pediatric mortality, survival status, and neurological outcome at hospital discharge also were obtained.nnnRESULTSnWith a total mortality of 923 during the study period and 233 victims of OHCA (including 221 who died and 12 who survived), OHCA caused 24% (221 of 923) of total pediatric mortality. Natural causes of OHCA amounted to 115 (49%) cases, with cardiac causes being most prevalent (n = 90, 39%). The incidence of pediatric OHCA was 9.0 per 100,000 pediatric person-years (95% confidence interval: 7.8 to 10.3), whereas the incidence of pediatric OHCA from cardiac causes was 3.2 (95% confidence interval: 2.5 to 3.9). Of 51 resuscitated patients, 12 (24%) survived; among survivors, 10 (83%) had a neurologically intact outcome.nnnCONCLUSIONSnOut-of-hospital cardiac arrest accounts for a significant proportion of pediatric mortality, and cardiac causes are the most prevalent causes of OHCA. The vast majority of OHCA survivors have a neurologically intact outcome.