Implementation trial of the basic life support termination of resuscitation rule: Reducing the transport of futile out-of-hospital cardiac arrests

Background

The basic life support (BLS) termination of resuscitation (TOR) rule recommends transport and continued resuscitation when cardiac arrest is witnessed by EMT-Ds, or there is a return of spontaneous circulation, or a shock is given, and prior studies have suggested the transport rate should fall to 37%.

Methods and results

This real-time prospective multi-center implementation trial evaluated the BLS TOR rule for compliance, transport rate and provider and physician comfort. Both provider and physician noted their decision-making rationale and ranked their comfort on a 5-point Likert scale. Functional survival was measured at discharge. Of 2421 cardiac arrests, 953 patients were eligible for the rule, which was applied correctly for 755 patients (79%) of which 388 were terminated. 565 patients were transported resulting in a reduction of the transport rate from 100% (historical control) to 59% (p < 0.001). The BLS TOR rule was not followed in 198 eligible patients (21%) and they were all transported despite meeting the criteria to terminate. Providers cited 241 reasons for non-compliance: family distress, short transport time interval, younger age and public venue. All 198 transported patients, non-compliant with the rule, died. Both providers and physicians were comfortable with using the rule to guide TOR (median [IQR] of 5 [4,5]; p < 0.001).

Conclusions

This implementation trial confirmed the accuracy of the BLS TOR rule in identifying futile out-of-hospital cardiac arrest (OHCA) resuscitations, significantly reduced the transport rate of futile OHCA and most providers and physicians were comfortable following the rule's recommendations.     

Intraosseous infusion of ice cold saline is less efficacious than intravenous infusion for induction of mild therapeutic hypothermia in a swine model of cardiac arrest

Background

Intravenous (IV) infusion of ice cold saline is an effective method to initiate induction of mild therapeutic hypothermia (MTH) following resuscitation from out-of-hospital cardiac arrest (OOHCA). Intraosseous (IO) infusion of cold saline may be an alternative method to induce MTH.

Objective

The goal of this study was to determine if IO infusion of cold saline is a comparable alternative to IV infusion for inducing MTH in a laboratory swine model of cardiac arrest.

Methods

Ten mixed breed swine were resuscitated from cardiac arrest and randomized post-resuscitation to infusion with ice cold saline using either IO (n = 5) or IV (n = 5) access. The study endpoints were either a goal esophageal temperature of 34 °C or the elapse of a 30 min time period, simulating a long prehospital transport.

Results

Four of five pigs in the IV infusion group achieved goal temperature within 30 min compared to 0/5 in the IO infusion group (p = 0.048). The mean esophageal temperature change was significantly higher in the IV group when compared to the IO group (p < 0.001). Post-arrest hemodynamic parameters were similar between the two groups.

Conclusions

IV infusion of ice cold saline is an efficacious method to achieve MTH in this swine model of cardiac arrest. Furthermore, IO infusion of cold saline is not sufficient to induce MTH in the time routinely available in the prehospital setting following OOHCA.     

Treatment of monitored out-of-hospital ventricular fibrillation and pulseless ventricular tachycardia utilising the precordial thump

Background

Few studies have described the value of the precordial thump (PT) as first-line treatment of monitored out-of-hospital cardiac arrest (OHCA) from ventricular fibrillation and pulseless ventricular tachycardia (VF/VT).

Methods

Patient data was extracted from the Victorian Ambulance Cardiac Arrest Registry (VACAR) for all OHCA witnessed by paramedics between 2003 and 2011. Adult patients who suffered a monitored VF/VT of presumed cardiac aetiology were included. Cases were excluded if the arrest occurred after arrival at hospital, or a ‘do not resuscitate’ directive was documented. Patients were assigned into two groups according to the use of the PT or defibrillation as first-line treatment. The study outcomes were: impact of first shock/thump on return of spontaneous circulation (ROSC), overall ROSC, and survival to hospital discharge.

Results

A total of 434 cases met the eligibility criteria, of which first-line treatment involved a PT in 103 (23.7%) and immediate defibrillation in 325 (74.8%) cases. Patient characteristics did not differ significantly between groups. Seventeen patients (16.5%) observed a PT-induced rhythm change, including five cases of ROSC and 10 rhythm deteriorations. Immediate defibrillation resulted in significantly higher levels of immediate ROSC (57.8% vs. 4.9%, p < 0.0001), without excess rhythm deteriorations (12.3% vs. 9.7%, p = 0.48). Of the five successful PT attempts, three required defibrillation following re-arrest. Overall ROSC and survival to hospital discharge did not differ significantly between groups.

Conclusion

The PT used as first-line treatment of monitored VF/VT rarely results in ROSC, and is more often associated with rhythm deterioration.     

Cold infusions alone are effective for induction of therapeutic hypothermia but do not keep patients cool after cardiac arrest

AIM OF THE STUDY: Cold infusions have proved to be effective for induction of therapeutic hypothermia after cardiac arrest but so far have not been used for hypothermia maintenance. This study investigates if hypothermia can be induced and maintained by repetitive infusions of cold fluids and muscle relaxants. MATERIAL AND METHODS: Patients were eligible, if they had a cardiac arrest of presumed cardiac origin and no clinical signs of pulmonary oedema or severely reduced left ventricular function. Rocuronium (0.5 mg/kg bolus, 0.5 mg/kg/h for maintenance) and crystalloids (30 ml/kg/30 min for induction, 10 ml/kg every 6h for 24h maintenance) were administered via large bore peripheral venous cannulae. If patients failed to reach 33+/-1 degrees C bladder temperature within 60 min, endovascular cooling was applied. RESULTS: Twenty patients with a mean age of 57 (+/-15) years and mean body mass index of 27 (+/-4)kg/m(2) were included (14 males). Mean temperature at initiation of cooling (median 27 (IQR 16; 87)min after admission) was 35.4 (+/-0.9) degrees C. In 13 patients (65%) the target temperature was reached within 60 min, 7 patients (35%) failed to reach the target temperature. Maintaining the target temperature was possible in three (15%) patients and no adverse events were observed. CONCLUSION: Cold infusions are effective for induction of hypothermia after cardiac arrest, but for maintenance additional cooling techniques are necessary in most cases.     

Prehospital induction of therapeutic hypothermia during CPR: a pilot study

AIM OF THE STUDY: We studied induction of therapeutic hypothermia during prehospital resuscitation from cardiac arrest using an infusion of ice-cold Ringer's solution in five adult patients. MATERIAL AND METHODS: Paramedics infused +4 degrees C Ringer's solution into the antecubital vein of the patients with a maximum rate of 33 ml/min to a target temperature of 33.0 degrees C. RESULTS: The mean infused volume of cold fluid was 14.0 ml/kg, which resulted in a mean decrease of 2.5 degrees C in nasopharyngeal temperature. The decrease in temperature continued after the cessation of infusion in two patients, causing suboptimal temperatures below 32 degrees C. CONCLUSION: We conclude that the infusion of small volumes of ice-cold Ringer's solution during resuscitation results in an effective decrease in nasopharyngeal temperature. Caution should be taken to avoid temperatures below the range of mild therapeutic hypothermia.     

A national resuscitation registry of out-of-hospital cardiac arrest in Germany—A pilot study

Background

Survival rate after out-of-hospital cardiac arrest (OHCA) has not significantly increased over the last decade. However, survival rate has been used as a quality benchmark for many emergency medical services. A uniform resuscitation registry may be advantageous for quality management of cardiopulmonary resuscitation (CPR). This study was conducted to evaluate the establishment of a national CPR registry in Germany.

Materials and methods

A prospective cohort study was performed that included 469 patients who experienced OHCA requiring CPR in the metropolitan area of Dortmund, Germany. Cardiac arrest was defined as concomitant appearance of unconsciousness, apnoea or gasping and pulselessness. All data were collected via a secure and confidential paper-based method as the data set ‘Preclinical care’.

Results

Quality of data was classified as ‘good’ in 33.4%, ‘moderate’ in 48.4%, and ‘bad’ in 18.2% of the patients, respectively. Sixty-two percent had OHCA in private residences, 24% of the patients had a first monitored rhythm of ventricular fibrillation (VF) or ventricular tachycardia (VT), 35.2% had return of spontaneous circulation (ROSC) on scene, and patients presenting VF/VT as the first monitored rhythm had higher ROSC rates (51.3%) compared to patients with asystole (22.6%).

Conclusion

The data set ‘Preclinical care’ proved to be congruent with the Utstein style, provided further information for national and international comparisons, and enabled a detailed analysis. Optimisation of data collection and introduction of strict control mechanisms may further improve data quality.     

Reduced effectiveness of hypothermia in patients lacking the wave V in auditory brainstem responses immediately following resuscitation from cardiac arrest

AIMS: Therapeutic hypothermia appears to improve the outcome of pre-hospital cardio-pulmonary arrest (CPA) in patients with an initial cardiac rhythm of ventricular fibrillation or nonperfusing ventricular tachycardia (VF/VT). Notwithstanding, the outcome of this procedure is certainly difficult to predict based solely on the initial rhythm. The aim of the present study was to predict the outcome using auditory brainstem responses (ABRs) in CPA patients treated with therapeutic hypothermia. DESIGN AND SETTING: A prospective observational study in the intensive care unit of a university hospital. PATIENTS: The study included 26 patients resuscitated from out-of-hospital CPA. INTERVENTIONS: Basic and advanced cardiac life support, intensive care and post-resuscitative hypothermia. MEASUREMENT AND RESULTS: ABRs were recorded immediately after the return of spontaneous circulation (ROSC). An ABR wave V was recorded in 16 patients. Among 8 patients with a favourable outcome, the initial rhythms were VF/VT in 6 patients and other rhythms in 2. All 10 patients without a detectable ABR wave V had an unfavourable outcome. The VF/VT as the initial arrest rhythm and the presence of wave V were significantly (p = 0.0095) correlated with a favourable outcome. The presence of wave V had a 100% sensitivity to a favourable outcome. CONCLUSION: The absence of the ABR wave V in the early phase after ROSC wave indicated a reduced effect of therapeutic hypothermia, even in cases that underwent hypothermia promptly after out-of-hospital CPA. Measurement of ABRs appears to be useful as a predictor of effectiveness and as a criterion for determining the indication for therapeutic hypothermia.     

Comparison of out-of-hospital cardiac arrest occurring before and after paramedic arrival: Epidemiology,survival to hospital discharge and 12-month functional recovery

BackgroundDespite immediate resuscitation, survival rates following out-of-hospital cardiac arrests (OHCA) witnessed by emergency medical service (EMS) are reportedly low. We sought to compare survival and 12-month functional recovery outcomes for OHCA occurring before and after EMS arrival.MethodsBetween 1st July 2008 and 30th June 2013, we included 8648 adult OHCA cases receiving an EMS attempted resuscitation from the Victorian Ambulance Cardiac Arrest Registry, and categorised them into five groups: bystander witnessed cases ± bystander CPR, unwitnessed cases ± bystander CPR, and EMS witnessed cases. The main outcomes were survival to hospital and survival to hospital discharge. Twelve-month survival with good functional recovery was measured in a sub-group of patients using the Extended Glasgow Outcome Scale (GOSE).ResultsBaseline and arrest characteristics differed significantly across groups. Unadjusted survival outcomes were highest among bystander witnessed cases receiving bystander CPR and EMS witnessed cases, however outcomes differed significantly between these groups: survival to hospital (46.0% vs. 53.4% respectively, p < 0.001); survival to hospital discharge (21.1% vs. 34.9% respectively, p < 0.001). When compared to bystander witnessed cases receiving bystander CPR, EMS witnessed cases were associated with a significant improvement in the risk adjusted odds of survival to hospital (OR 2.02, 95% CI: 1.75–2.35), survival to hospital discharge (OR 6.16, 95% CI: 5.04–7.52) and survival to 12 months with good functional recovery (OR 5.56, 95% CI: 4.18–7.40).ConclusionWhen compared to OHCA occurring prior to EMS arrival, EMS witnessed arrests were associated with significantly higher survival to hospital discharge rates and favourable neurological recovery at 12-month post-arrest.     

温州地区开展亚低温治疗对心肺复苏后昏迷患者预后影响的研究

目的探讨温州地区推广亚低温治疗（HT）对心肺复苏（CPR）后昏迷患者预后的影响。 方法温州地区成立1家推广示范基地及10家推广基地,自2014年1月至2016年12月,对CPR后昏迷患者实施HT。记录所有患者亚低温治疗相关信息,比较推广期间3年患者ICU出院存活率、神经功能恢复良好率及严重致残率。 结果推广期间共对133例CPR后昏迷患者实施HT,推广第1年、第2年、第3年分别为28、46、59例。推广第1年、第2年、第3年达到目标体温时间[8.0（3.0,18.8）、10.0（4.8,20.0）、6.0（2.0,12.0）h]、药物使用率[17（60.7%）、43（93.5%）、42（71.2%）]及肌松剂使用率[0（0%）、1（2.2%）、13（22.0%）]比较,差异均有统计学意义（H = 10.475,P = 0.005;χ² = 12.250,P = 0.002;χ² = 17.647,P < 0.001）。推广期间ICU出院存活率呈现逐年上升趋势,严重致残率呈现逐年下降趋势;但3年间比较差异均无统计学意义（χ² = 2.537,P = 0.281;χ² = 0.308,P = 0.857）。推广3年间神经功能恢复良好率比较,差异有统计学意义（χ² = 12.232,P =0.002）,且推广第3年较第1年及第2年神经功能恢复良好率更高[16（27.1%）、1（3.6%）、3（6.5%）,P均< 0.017]。 结论规范化的HT能有效地促进神经功能恢复。     

Full recovery of an avalanche victim with profound hypothermia and prolonged cardiac arrest treated by extracorporeal re-warming

Survival of hypothermic avalanche victims with cardiac arrest is rare. This report describes full recovery of a 29-year-old backcountry skier completely buried for 100 min at 3.0m (9.8 ft) depth. On extrication he was unconscious, but breathing spontaneously into an air pocket; core body temperature measured 22.0 degrees C (71.6 degrees F). He was intubated and ventilated on site. Ventricular fibrillation commenced during helicopter transportation, whereby chest compression was lacking for 15 min. At the nearest hospital continuous cardiopulmonary resuscitation was initiated, but defibrillation failed. Tympanic core body temperature measurement confirmed life-threatening hypothermia of 21.7 degrees C (71.1 degrees F) and serum K(+) was 4.3 mmol/l, necessitating transferral to a hospital with cardiopulmonary bypass facilities. Defibrillation finally succeeded following re-warming, by femoral veno-arterial bypass, to 34.5 degrees C (94.1 degrees F). Total duration of cardiac arrest was 150 min. The patient developed pulmonary oedema, treated by extracorporeal membrane oxygenation, but progressed well and was discharged from hospital on day 17, fit to resume professional and social activities. Follow-up cerebral magnetic resonance imaging 2 years after avalanche burial demonstrated only minimal changes attributable to unrelated, prior cranial trauma. Extensive neurological and psychological investigations gave excellent results. This report confirms previous literature that an air pocket with patent airways is essential for survival of a completely buried avalanche victim after 35 min and endorses the recommended management strategies of the International Commission for Mountain Emergency Medicine ICAR MEDCOM. In particular, all hypothermic victims extricated with an air pocket and free airways must be treated optimistically, even despite prolonged cardiac arrest. This remarkable case documents the fastest drop in core temperature ever recorded during snow burial, namely 9.0 degrees C (16.2 degrees F)/h, and the second-lowest reversible core temperature in avalanche literature.     

心脏骤停后心肺复苏和心肺脑复苏成功病例的对比分析

目的 探讨影响心脏骤停患者成功脑复苏的相关因素.方法 回顾对比分析心脏骤停后成功心肺脑复苏(A组,n=38)和仅心肺复苏成功(B组,n=42)患者之间的相关指标,包括性别、年龄、原发疾病、心脏骤停原因、心脏骤停环境、心脏骤停相关时间和心肺复苏后相关治疗持续时间.结果 两组性别比和平均年龄比较差异无统计学意义(P＞0.05).原发疾病:A组以外科为主(78.9%),B组以内科为主(61.9%),两组比较差异有统计学意义(P＜0.005).心脏骤停原因:A组31例(81.6%)为急性缺氧、低血压、内脏神经反射和单纯心脏疾患, B组30例(71.4%)为慢性缺氧和慢性心脏病,两组比较差异有统计学意义(P＜0.005).心脏骤停环境:A组24例(63.2%)发生在手术室和ICU,B组22例(52.4%)发生在普通病房,两组比较差异有统计学意义(P＜0.005).心脏骤停相关时间:A组心脏骤停持续时间(8.2±8.7)min,自主心跳恢复时间(6.7±8.4)min,脑缺血缺氧时间(1.5±1.3)min,均明显短于B组[分别为(30.8±26.2)min、(27.7±24.9)min和(3.1±3.1)min,P＜0.001或P＜0.005].心肺复苏后相关治疗持续时间:A组亚低温持续时间(4.0±2.6)d,呼吸机持续时间(11.1±19.7)d,与B组[(5.9±3.8)d和(15.4±29.3)d]比较差异无统计学意义(P＞0.05).Logistic多因素回归分析显示,原发疾病(OR=6.22,95%CI 1.64～23.46)、心脏骤停持续时间(OR=1.11,95%CI 1.04～1.19)和心脏骤停发生环境(OR=4.51,95%CI 1.22～16.61)与成功脑复苏的关系更密切,成为三个独立影响因素.结论 没有明显慢性疾病,在手术室和ICU以急性缺氧、低血压和单纯心脏原因发生的心脏骤停,抢救及时有效,复苏后处理恰当、合理,尽早实施全面脑保护是成功脑复苏的有利因素.     

Delayed versus immediate defibrillation for out-of-hospital cardiac arrest due to ventricular fibrillation: A systematic review and meta-analysis of randomised controlled trials

Background

Human studies over the last decade have indicated that delaying initial defibrillation to allow a short period of cardiopulmonary resuscitation (CPR) may promote a more responsive myocardial state that is more likely to respond to defibrillation and result in increased rates of restoration of spontaneous circulation (ROSC) and/or survival. Out-of-hospital studies have produced conflicting results regarding the benefits of CPR prior to defibrillation in relation to survival to hospital discharge. The aim of this study was to conduct a systematic review and meta-analysis of randomised controlled trials comparing the effect of delayed defibrillation preceded by CPR with immediate defibrillation on survival to hospital discharge.

Methods

A systematic literature search of key electronic databases including Medline, EMBASE, and the Cochrane Library was conducted independently by two reviewers. Randomised controlled trials meeting the eligibility criteria were critically appraised according to the Cochrane Group recommended methodology. Meta-analyses were conducted for the outcomes of survival to hospital discharge overall and according to response time of emergency medical services.

Results

Three randomised controlled trials were identified which addressed the question of interest. All included studies were methodologically appropriate to include in a meta-analysis. Pooled results from the three studies demonstrated no benefit from providing CPR prior to defibrillation compared to immediate defibrillation for survival to hospital discharge (OR 0.94 95% CI 0.46-1.94). Meta-analysis of results according to ambulance response time (≤5 min or >5 min) also showed no difference in survival rates.

Conclusion

Delaying initial defibrillation to allow a short period of CPR in out-of-hospital cardiac arrest due to VF demonstrated no benefit over immediate defibrillation for survival to hospital discharge irrespective of response time. There is no evidence that CPR before defibrillation is harmful. Based on the existing evidence, EMS jurisdictions are justified continuing with current practice using either defibrillation strategy.     

The impact of partial resuscitation attempts on the reported outcomes of out-of-hospital cardiac arrest in Victoria,Australia: Implications for Utstein-style outcome reports

Background

Success rates from cardiopulmonary resuscitation (CPR) are often quantified by Utstein-style outcome reports in populations who receive an attempted resuscitation. In some cases, evidence of futility is ascertained after a partial resuscitation attempt has been administered, and these cases reduce the overall effectiveness of CPR. We examine the impact of partial resuscitation attempts on the reported outcomes of out-of-hospital cardiac arrest (OHCA) in Victoria, Australia.

Methods

Between 2002 and 2012, 34,849 adult OHCA cases of presumed cardiac aetiology were included from the Victorian Ambulance Cardiac Arrest Registry. Resuscitation attempts lasting ≤10 min in cases which died on scene were defined as a partial resuscitation. We used logistic regression to identify factors associated with a partial resuscitation attempt in the emergency medical service (EMS) treated population. Survival outcomes with and without partial resuscitations were compared across included years.

Results

The proportion of partial resuscitations in the overall EMS treated population increased significantly from 8.6% in 2002 to 18.8% in 2012 (p for trend < 0.001), and were largely supported by documented evidence of irreversible death. Partial resuscitations were independently associated with older age, female gender, initial non-shockable rhythm, prolonged downtime, and lower skill level of EMS personnel. Selectively excluding partial resuscitations increased event survival by 7.6% (95% CI 4.1–11.2%), and survival to hospital discharge increased by 3.1% (95% CI 0.5–5.7%) in 2012 (p < 0.001 for both).

Conclusion

In our EMS system, evidence of futility was often identified after the commencement of a partial resuscitation attempt. Excluding these events from OHCA outcome reports may better reflect the overall effectiveness of CPR.     

Assessment of intravascular volume by transthoracic echocardiography during therapeutic hypothermia and rewarming in cardiac arrest survivors

AimTo study haemodynamic effects and changes in intravascular volume during hypothermia treatment, induced by ice-cold fluids and maintained by ice-packs followed by rewarming in patients after resuscitation from cardiac arrest.Materials and methodsIn 24 patients following successful restoration of spontaneous circulation (ROSC), hypothermia was induced with infusion of 4 °C normal saline and maintained with ice-packs for 26 h after ROSC. This was followed by passive rewarming. Transthoracic echocardiography was performed at 12, 24 and 48 h after ROSC to evaluate ejection fraction and intravascular volume status. Central venous pressure (CVP), central venous oxygen saturation (ScvO₂) and serum lactate were measured. Fluid balance was calculated.ResultsTwelve hours after ROSC, two separate raters independently estimated that 10 and 13 out of 23 patients had a decreased intravascular volume using transthoracic echocardiography. After 24 and 48 h this number had increased further to 14 and 13 out of 19 patients and 13 and 12 out of 21 patients. Calculated fluid balance was positive (4000 ml the day 1 and 2500 ml day 2). There was no difference in ejection fraction between the recording time points. Serum lactate and ScvO₂ were in the normal range when echocardiography exams were performed. CVP did not alter over time.ConclusionsOur results support the hypothesis that inducing hypothermia following cardiac arrest, using cold intravenous fluid infusion does not cause serious haemodynamic side effects. Serial transthoracic echocardiographic estimation of intravascular volume suggests that many patients are hypovolaemic during therapeutic hypothermia and rewarming in spite of a positive fluid balance.     

新型大鼠心跳骤停和复苏的机械装置

目的研发由电磁阀系统总控制、压缩气体驱动的新型大鼠电刺激诱发心跳骤停和复苏的机械装置,并探讨其有效性和安全性。方法选用Sprague-Dawley雄性大鼠20只,应用自主开发研制的心跳骤停和复苏机械装置,持续交流电经右心室内膜致颤。在6min心室颤动后,开始给予6min的机械胸外按压和同步机械通气,随后双向波经胸体外除颤。结果15只大鼠复苏成功,自主循环恢复率为75%。电刺激后所有大鼠立刻出现心室颤动,3min的电刺激停止后动物持续表现为室颤而没有自发转复心律现象。心肺复苏期间恢复自主循环组其冠状动脉灌注压恒定在24mmHg左右,显著高于未能恢复自主循环组。结论本新型大鼠心跳骤停和心肺复苏装置的有效性和安全性高,可最大限度减少实验的误差,具有一定的推广应用前景。     

Active compression-decompression cardiopulmonary resuscitation (CPR) versus standard CPR for cardiac arrest patients: a meta-analysis

BACKGROUND:

Active compression-decompression cardiopulmonary resuscitation (ACDCPR) has been popular in the treatment of patients with cardiac arrest (CA). However, the effect of ACD-CPR versus conventional standard CPR (S-CRP) is contriversial. This study was to analyze the efficacy and safety of ACD-CPR versus S-CRP in treating CA patients.

METHODS:

Randomized or quasi-randomized controlled trials published from January 1990 to March 2011 were searched with the phrase “active compression-decompression cardiopulmonary resuscitation and cardiac arrest” in PubMed, EmBASE, and China Biomedical Document Databases. The Cochrane Library was searched for papers of meta-analysis. Restoration of spontaneous circulation (ROSC) rate, survival rate to hospital admission, survival rate at 24 hours, and survival rate to hospital discharge were considered primary outcomes, and complications after CPR were viewed as secondary outcomes. Included studies were critically appraised and estimates of effects were calculated according to the model of fixed or random effects. Inconsistency across the studies was evaluated using the I2 statistic method. Sensitivity analysis was made to determine statistical heterogeneity.

RESULTS:

Thirteen studies met the criteria for this meta-analysis. The studies included 396 adult CA patients treated by ACD-CPR and 391 patients by S-CRP. Totally 234 CA patients were found out hospitals, while the other 333 CA patients were in hospitals. Two studies were evaluated with high-quality methodology and the rest 11 studies were of poor quality. ROSC rate, survival rate at 24 hours and survival rate to hospital discharge with favorable neurological function indicated that ACD-CPR is superior to S-CRP, with relative risk (RR) values of 1.39 (95% CI 0.99–1.97), 1.94 (95% CI 1.45–2.59) and 2.80 (95% CI 1.60–5.24). No significant differences were found in survival rate to hospital admission and survival rate to hospital discharge for ACD-CPR versus S-CRP with RR values of 1.06 (95% CI 0.76–1.60) and 1.00 (95% CI 0.73–1.38).

CONCLUSION:

Quality controlled studies confirmed the superiority of ACD-CPR to S-CRP in terms of ROSC rate and survival rate at 24 hours. Compared with S-CRP, ACD-CPR could not improve survival rate to hospital admission or survival rate to hospital discharge.KEY WORDS: Active compression-decompression, Cardiopulmonary resuscitation, Cardiac arrest, Meta-analysis     

Performance of a rectilinear biphasic waveform in defibrillation of presenting and recurrent ventricular fibrillation: a prospective multicenter study

Objectives

We tested the hypothesis that shock success differs with initial and recurrent episodes of ventricular fibrillation (VF).

Methods

From September 2008 to March 2010 out-of-hospital cardiac arrest patients with VF as the initial rhythm at 9 study sites were defibrillated by paramedics using a rectilinear biphasic waveform. Shock success was defined as termination of VF within 5 s post-shock. We used generalized estimating equation (GEE) analysis to assess the association between shock type (initial versus refibrillation) and shock success.

Results

Ninety-four patients presented in VF. Mean age was 65.4 years, 78.7% were male, and 80.9% were bystander-witnessed. VF recurred in 75 (79.8%). There were 338 shocks delivered for initial (n = 90) or recurrent (n = 248) VF available for analysis. Initial shocks terminated VF in 79/90 (87.8%) and subsequent shocks in 209/248 (84.3%). GEE odds ratio (OR) for shock type was 1.37 (95% CI 0.68-2.74). After adjusting for potential confounders, the OR for shock type remained insignificant (1.33, 95% CI 0.60-2.53). We observed no significant difference in ROSC (54.7% versus 52.6%, absolute difference 2.1%, p = 0.87) or neurologically intact survival to hospital discharge (21.9% versus 33.3%, absolute difference 11.4%, p = 0.31) between those with and without VF recurrence.

Conclusions

Presenting VF was terminated with one shock in 87.8% of cases. We observed no significant difference in the frequency of shock success between initial versus recurrent VF. VF recurred in the majority of patients and did not adversely affect shock success, ROSC, or survival.