Mechanical versus manual chest compression for out-of-hospital cardiac arrest (PARAMEDIC): a pragmatic, cluster randomised controlled trial.

BACKGROUND: Mechanical chest compression devices have the potential to help maintain high-quality cardiopulmonary resuscitation (CPR), but despite their increasing use, little evidence exists for their effectiveness. We aimed to study whether the introduction of LUCAS-2 mechanical CPR into front-line emergency response vehicles would improve survival from out-of-hospital cardiac arrest. METHODS: The pre-hospital randomised assessment of a mechanical compression device in cardiac arrest (PARAMEDIC) trial was a pragmatic, cluster-randomised open-label trial including adults with non-traumatic, out-of-hospital cardiac arrest from four UK Ambulance Services (West Midlands, North East England, Wales, South Central). 91 urban and semi-urban ambulance stations were selected for participation. Clusters were ambulance service vehicles, which were randomly assigned (1:2) to LUCAS-2 or manual CPR. Patients received LUCAS-2 mechanical chest compression or manual chest compressions according to the first trial vehicle to arrive on scene. The primary outcome was survival at 30 days following cardiac arrest and was analysed by intention to treat. Ambulance dispatch staff and those collecting the primary outcome were masked to treatment allocation. Masking of the ambulance staff who delivered the interventions and reported initial response to treatment was not possible. The study is registered with Current Controlled Trials, number ISRCTN08233942. FINDINGS: We enrolled 4471 eligible patients (1652 assigned to the LUCAS-2 group, 2819 assigned to the control group) between April 15, 2010 and June 10, 2013. 985 (60%) patients in the LUCAS-2 group received mechanical chest compression, and 11 (<1%) patients in the control group received LUCAS-2. In the intention-to-treat analysis, 30 day survival was similar in the LUCAS-2 group (104 [6%] of 1652 patients) and in the manual CPR group (193 [7%] of 2819 patients; adjusted odds ratio [OR] 0·86, 95% CI 0·64-1·15). No serious adverse events were noted. Seven clinical adverse events were reported in the LUCAS-2 group (three patients with chest bruising, two with chest lacerations, and two with blood in mouth). 15 device incidents occurred during operational use. No adverse or serious adverse events were reported in the manual group. INTERPRETATION: We noted no evidence of improvement in 30 day survival with LUCAS-2 compared with manual compressions. On the basis of ours and other recent randomised trials, widespread adoption of mechanical CPR devices for routine use does not improve survival. FUNDING: National Institute for Health Research HTA - 07/37/69.

Protocol C: a nonguidelines-compliant approach to improve survival of patients with out-of-hospital cardiac arrest.

PURPOSE OF REVIEW: To describe a resuscitation protocol for out-of-hospital cardiac arrest designed for healthcare professionals that demands more from rescuers than does conventional cardiopulmonary resuscitation. It was introduced with the aim of improving survival that has remained disappointingly poor worldwide. RECENT FINDINGS: Survival to hospital discharge, that could be measured accurately in one city, improved appreciably with the use of the novel protocol. The implications are discussed in relation to the scientific background and relevant literature. SUMMARY: Uniform resuscitation protocols for lay and for professional use may not be appropriate. Only randomized trials can indicate the potential value of this challenge to conventional wisdom.

Achy breaky makey wakey heart? A randomised crossover trial of musical prompts.

OBJECTIVE: Compared with no music (NM), does listening to 'Achy breaky heart' (ABH) or 'Disco science' (DS) increase the proportion of prehospital professionals delivering chest compressions at 2010 guideline-compliant rates of 100-120 bpm and 50-60 mm depths? METHODS: A randomised crossover trial recruiting at an Australian ambulance conference. Volunteers performed three 1-min sequences of continuous chest compressions on a manikin accompanied by NM, repeated choruses of ABH and DS, prerandomised for order. RESULTS: 37 of 74 participants were men; median age 37 years; 61% were paramedics, 20% students and 19% other health professionals. 54% had taken cardiopulmonary resuscitation training within 1 year. Differences in compression rate (mode, IQR) were significant for NM (105, 99-116) versus ABH (120, 107-120) and DS (104, 103-107) versus ABH (p<0.001) but not NM versus DS (p=0.478). Differences in proportions of participants compressing at 100-120 bpm were significant for DS (61/74, 82%) versus NM (48/74, 65%, p=0.007) and DS versus ABH (47/74, 64%, p=0.007) but not NM versus ABH (p=1). Differences in compression depth were significant for NM (48 mm, 46-59 mm) versus DS (54 mm, 44-58 mm, p=0.042) but not NM versus ABH (54 mm, 43-59 mm, p=0.065) and DS versus ABH (p=0.879). Differences in proportions of subjects compressing at 50-60 mm were not significant (NM 31/74 (42%); ABH 32/74 (43%); DS 29/74 (39%); all p>0.5). CONCLUSIONS: Listening to DS significantly increased the proportion of prehospital professionals compressing at 2010 guideline-compliant rates. Regardless of intervention more than half gave compressions that were too shallow. Alternative audible feedback mechanisms may be more effective.

The reliability of vital signs in estimating pain severity among adult patients treated by paramedics.

BACKGROUND: The aim of this study was to examine the strength of correlation between initial pain severity score and systolic blood pressure, heart rate and respiratory rates among adults reporting pain in the prehospital setting as a means of validating the presence and severity of pain. METHODS: A retrospective cohort study was conducted including all adults with a Glasgow Coma Score >12 assessed by paramedics in a metropolitan area over a 7 day period in 2005. Pain was self-scored by patients using a 0-10 numeric rating scale (NRS). RESULTS: Of the patients transported, 1766/3357 (53%) reported pain, and an NRS score was recorded for 1286. Median age was 57 years, 51% were women, and median initial NRS was six. Mean heart rate was 85 (95% CI 84 to 86), mean systolic blood pressure was 139 mmHg (95% CI 138 to 141) and mean respiratory rate was 18 (95% CI 18 to 18). There was no significant correlation between NRS and heart rate (r=0.002, p=0.61, 95% CI -0.007 to +0.011) or blood pressure (r=-0.0007, p=0.81, 95% CI -0.007 to +0.005), although this was statistically significant for initial pain score and respiratory rate (r 0.058, p=0.001, 95% CI 0.024 to 0.093). CONCLUSION: A lack of any meaningful correlation between pain scores and changes in vital signs in this population demonstrates that these signs cannot be used to validate the severity of pain reported by adult patients.

Does the introduction of a COPD pro-forma improve the standards of care delivered by junior doctors in the emergency department.

AIM: To determine if pro-forma based management improves standards of care delivered by junior doctors in chronic obstructive pulmonary disease (COPD) patients in the Emergency Department (ED). INTRODUCTION: National COPD audits have found large variations in ED standards of care compared to guidelines. They concluded that the publication of guidelines itself does not translate to an improvement in care. METHOD: A pro-forma based on the British Thoracic Society Guidelines on COPD, 1997, NICE Guidelines CG12, 2004 and Non Invasive Ventilation (NIV), 2002 was devised and implemented following targeted education. Data were collected pre and post pro-forma implementation and analysed. The primary end point was categorisation of respiratory failure as it was felt that this concept was fundamental in COPD management. Secondary endpoints included the administration of controlled oxygen, repeat blood gases and appropriate referral for NIV. RESULTS: There were a total of 55 patients in each group. The correct categorisation of respiratory failure improved significantly from 4% in the pre- compared to 89% (p < 0.0001) in the post-intervention group. Similarly the administration of controlled oxygen (47% compared to 92%, p < 0.0001), repeat arterial blood gases (50% compared to 83%, p = 0.0098), and appropriate referral for NIV (33% compared to 100%, p = 0.0023) showed significant improvement after the pro-forma was introduced. CONCLUSION: Pro-forma aided management significantly improves the standards of care in COPD patients in the ED.

'Should I stay or should I go?' Deciding whether to go to hospital after a 999 call.

OBJECTIVE: In most UK ambulance services, crews attending someone who has phoned the emergency services on '999' will take the patient to hospital, unless the patient makes the decision to stay at home (or wherever they happen to be when the ambulance arrives). Safety concerns have been raised about non-conveyance decisions. We undertook a study of one UK Ambulance Service to examine ambulance crew members' views on how decision-making about non-conveyance works in practice in relation to non-urgent calls. METHODS: A total of 25 paramedics took part in three focus groups. Focus groups were transcribed and analysed thematically. RESULTS: The ambulance service's apparently straightforward guidance on decision-making about non-conveyance proved tricky in the messiness of the real world, for two reasons. The first was to do with the notion of the patient's capacity to make decisions and how this was interpreted. The second was to do with the complexity of the decision-making process, in which the patient, the crew and, in many cases, family or carers often take part in negotiation and de facto joint decision-making. CONCLUSIONS: There is a mismatch between policy and practice in relation to non-conveyance decisions. Findings should be built into research and service development in this rapidly changing field of practice in emergency and/or unscheduled care. The commonly accepted perspective on shared decision-making should be extended to include the context of '999' ambulance calls.

Prehospital randomised assessment of a mechanical compression device in out-of-hospital cardiac arrest (PARAMEDIC): a pragmatic, cluster randomised trial and economic evaluation.

BACKGROUND: Mechanical chest compression devices may help to maintain high-quality cardiopulmonary resuscitation (CPR), but little evidence exists for their effectiveness. We evaluated whether or not the introduction of Lund University Cardiopulmonary Assistance System-2 (LUCAS-2; Jolife AB, Lund, Sweden) mechanical CPR into front-line emergency response vehicles would improve survival from out-of-hospital cardiac arrest (OHCA). OBJECTIVE: Evaluation of the LUCAS-2 device as a routine ambulance service treatment for OHCA. DESIGN: Pragmatic, cluster randomised trial including adults with non-traumatic OHCA. Ambulance dispatch staff and those collecting the primary outcome were blind to treatment allocation. Blinding of the ambulance staff who delivered the interventions and reported initial response to treatment was not possible. We also conducted a health economic evaluation and a systematic review of all trials of out-of-hospital mechanical chest compression. SETTING: Four UK ambulance services (West Midlands, North East England, Wales and South Central), comprising 91 urban and semiurban ambulance stations. Clusters were ambulance service vehicles, which were randomly assigned (approximately 1 : 2) to the LUCAS-2 device or manual CPR. PARTICIPANTS: Patients were included if they were in cardiac arrest in the out-of-hospital environment. Exclusions were patients with cardiac arrest as a result of trauma, with known or clinically apparent pregnancy, or aged < 18 years. INTERVENTIONS: Patients received LUCAS-2 mechanical chest compression or manual chest compressions according to the first trial vehicle to arrive on scene. MAIN OUTCOME MEASURES: Survival at 30 days following cardiac arrest; survival without significant neurological impairment [Cerebral Performance Category (CPC) score of 1 or 2]. RESULTS: We enrolled 4471 eligible patients (1652 assigned to the LUCAS-2 device and 2819 assigned to control) between 15 April 2010 and 10 June 2013. A total of 985 (60%) patients in the LUCAS-2 group received mechanical chest compression and 11 (< 1%) patients in the control group received LUCAS-2. In the intention-to-treat analysis, 30-day survival was similar in the LUCAS-2 (104/1652, 6.3%) and manual CPR groups [193/2819, 6.8%; adjusted odds ratio (OR) 0.86, 95% confidence interval (CI) 0.64 to 1.15]. Survival with a CPC score of 1 or 2 may have been worse in the LUCAS-2 group (adjusted OR 0.72, 95% CI 0.52 to 0.99). No serious adverse events were noted. The systematic review found no evidence of a survival advantage if mechanical chest compression was used. The health economic analysis showed that LUCAS-2 was dominated by manual chest compression. LIMITATIONS: There was substantial non-compliance in the LUCAS-2 arm. For 272 out of 1652 patients (16.5%), mechanical chest compression was not used for reasons that would not occur in clinical practice. We addressed this issue by using complier average causal effect analyses. We attempted to measure CPR quality during the resuscitation attempts of trial participants, but were unable to do so. CONCLUSIONS: There was no evidence of improvement in 30-day survival with LUCAS-2 compared with manual compressions. Our systematic review of recent randomised trials did not suggest that survival or survival without significant disability may be improved by the use of mechanical chest compression. FUTURE WORK: The use of mechanical chest compression for in-hospital cardiac arrest, and in specific circumstances (e.g. transport), has not yet been evaluated. TRIAI REGISTRATION: Current Controlled Trials ISRCTN08233942. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 11. See the NIHR Journals Library website for further project information.

Optimal refresher training intervals for AED and CPR skills: a randomised controlled trial.

AIM: To determine the optimal refresher training interval for lay volunteer responders in the English National Defibrillator Programme who had previously undertaken a conventional 4-h initial class and a first refresher class at 6 months. METHODS: Subjects were randomised to receive either two additional refresher classes at intervals of 7 and 12 months or one additional refresher class after 12 months. RESULTS: Greater skill loss had occurred when the second refresher class was undertaken at 12 compared with 7 months. Skill retention however, was higher in the former group, ultimately resulting in no significant difference in final skill performance. There was no significant difference in performance between subjects attending two versus three refresher classes. On completion of refresher training all subjects were able to deliver countershocks, time to first shock decreased by 17s in both groups, and the proportion of subjects able to perform most skills increased. The execution of several important interventions remained poor, regardless of the total number of classes attended or the interval between them. These included CPR skills, defibrillation pad placement, and pre-shock safety checks. Refresher classes held more frequently and at shorter intervals increased subjects' self-assessed confidence, possibly indicating greater preparedness to use an AED in a real emergency. CONCLUSIONS: This study shows that the ability to deliver countershocks is maintained whether the second refresher class is held at seven or 12 months after the first. To limit skill deterioration between classes, however, refresher training intervals should not exceed 7 months. The quality of instruction given should be monitored carefully. Learning and teaching strategies require review to improve skill acquisition and maintenance.

Associations between organizational and incident factors and emotional distress in emergency ambulance personnel.

OBJECTIVES: This study examined the prevalence and correlates of post-traumatic stress disorder (PTSD), anxiety and depression among emergency ambulance personnel. DESIGN AND METHOD: A questionnaire and reminder were sent anonymously to 1029 emergency ambulance personnel in a large ambulance service. RESULTS: Among the 617 respondents, levels of PTSD symptoms did not differ according to grade, but men had a higher prevalence rate than women. Key predictors of the severity of symptoms were organizational stress, the frequency of experiencing potentially traumatic incidents, length of service, and dissociation in response to an index incident. The degree of organizational, but not incident-related, stress discriminated between 'cases' and 'non-cases'. Nine and 23% of recorded scores indicated clinical levels of depression and anxiety respectively. Several work factors were associated with these emotions, explaining 38% of anxiety and 31% of depression scores. CONCLUSION: Both organizational and individually based interventions may be necessary to minimize PTSD and other emotional disorders among ambulance personnel.

Reliability of the Cardiff Test of basic life support and automated external defibrillation version 3.1.

The introduction of the European Resuscitation Guidelines (2000) for cardiopulmonary resuscitation (CPR) and automated external defibrillation (AED) prompted the development of an up-to-date and reliable method of assessing the quality of performance of CPR in combination with the use of an AED. The Cardiff Test of basic life support (BLS) and AED version 3.1 was developed to meet this need and uses standardised checklists to retrospectively evaluate performance from analyses of video recordings and data drawn from a laptop computer attached to a training manikin. This paper reports the inter- and intra-observer reliability of this test. Data used to assess reliability were obtained from an investigation of CPR and AED skill acquisition in a lay responder AED training programme. Six observers were recruited to evaluate performance in 33 data sets, repeating their evaluation after a minimum interval of 3 weeks. More than 70% of the 42 variables considered in this study had a kappa score of 0.70 or above for inter-observer reliability or were drawn from computer data and therefore not subject to evaluator variability. 85% of the 42 variables had kappa scores for intra-observer reliability of 0.70 or above or were drawn from computer data. The standard deviations for inter- and intra-observer measures of time to first shock were 11.6 and 7.7 s, respectively. The inter- and intra-observer reliability for the majority of the variables in the Cardiff Test of BLS and AED version 3.1 is satisfactory. However, reliability is less acceptable with respect to shaking when checking for responsiveness, initial check/clearing of the airway, checks for signs of circulation, time to first shock and performance of interventions in the correct sequence. Further research is required to determine if modifications to the method of assessing these variables can increase reliability.

To blow or not to blow: a randomised controlled trial of compression-only and standard telephone CPR instructions in simulated cardiac arrest.

This randomised controlled trial used a manikin model of cardiac arrest to compare skill performance in untrained lay persons randomised to receive either compression-only telephone CPR (Compression-only tel., n=29) or standard telephone CPR instructions (Standard tel., n=30). Performance was evaluated during standardised 10 min cardiac arrest simulations using a video recording and data from a laptop computer connected to the training manikin. A number of subjects in both groups did not open the airway. More than 75% in the Standard tel. group failed to deliver two effective initial rescue breaths, and only 17% provided an adequate inflation volume for subsequent breaths, delivering a median of only five inflations during the entire scenario. Most subjects in both groups gave chest compressions that were too shallow and at an inappropriately rapid rate. Hand position was also poor, but was worse in the group given simplified instructions. There was a significant delay to first compression in both groups, although this interval was shortened by over a minute when ventilations were eliminated from the telephone instruction algorithm (245 vs. 184 s, P<0.001). Over two-and-a-half times as many chest compressions were delivered during an average ambulance response time with compression-only telephone directions compared with standard CPR (461 vs. 186, P<0.001). These variables may be critical in predicting survival from out-of-hospital cardiac arrest. Further research is necessary to establish if modifications to scripted telephone instructions can remedy the identified performance deficiencies. Eliminating instructions for rescue breaths from scripted telephone directions will have little impact on the ventilation of most patients. Research is required to determine if the consequent reduction in the delay to starting chest compressions and the significant increase in the number of compressions delivered can increase survival from out-of-hospital cardiac arrest.

Skill acquisition and retention in automated external defibrillator (AED) use and CPR by lay responders: a prospective study.

This prospective study evaluated the acquisition and retention of skills in cardio-pulmonary resuscitation (CPR) and the use of the automated external defibrillator (AED) by lay volunteers involved in the Department of Health, England National Defibrillator Programme. One hundred and twelve trainees were tested immediately before and after and initial 4-h class; 76 were similarly reassessed at refresher training 6 months later. A standardised test scenario that required assessment of the casualty, CPR and the use of on AED was evaluated using recording manikin data and video recordings. Before training only 44% of subjects delivered a shock. Afterwards, all did so and the average delay to first shock was reduced by 57 s. All trainees placed the defibrillator electrodes in an "acceptable" position after training, but very few did so in the recommended "ideal" position. After refresher training 80% of subjects used the correct sequence for CPR and shock delivery, yet a third failed to perform adequate safety checks before all shocks. The trainees self-assessed AED competence score was 86 (scale 0-100) after the initial class and their confidence that they would act in a real emergency was rated at a similar level. Initial training improved performance of all CPR skills, although all except compression rate had deteriorated after 6 months. The proportion of subjects able to correctly perform most CPR skill was higher following refresher training that after the initial class. Although this course was judged to be effective in teaching delivery of counter-shocks, the need was identified for more emphasis on positioning of electrodes, pre-shock safety checks, airway opening, ventilation volume, checking for signs of a circulation, hand positioning, and depth and rate of chest compressions.

Trials of teaching methods in basic life support (4): comparison of simulated CPR performance at unannounced home testing after conventional or staged training.

This study compares the retention of basic life support (BLS) skills after 6 and 12 months by lay persons trained either in a conventional manner, or using a staged approach. Three classes, each of 2h, were offered to volunteers over a period of 4 months. For the conventional group, the second and third classes consisted of review of skills. Those in the staged group were first taught chest compression alone; chest compression with ventilation in a ratio of 50:5 was introduced at the second class; full standard CPR was taught at the third class. A total of 495 volunteers entered the study, 262 being randomly allocated to conventional training, and 233 to staged training. More of those who received staged training attended a second (78 volunteers) and third class (41 volunteers), compared with those who received conventional training (36 and 17, respectively). The objective of this study, however, was to compare the strategies of the different training methods. A total of 291 volunteers (167 conventional and 124 staged training) were available for unannounced home testing of full conventional CPR 6 months after initial training, and 260 volunteers (135 conventional and 125 staged training) were tested at 12 months. At 6 months, those taught by the staged method were significantly better at time to first compression (P < 0.0001), compression rate (P = 0.024), and hand position (P = 0.0001). At 12 months, those taught by the staged method were significantly better at shouting for help (P = 0.005), time to first compression (P < 0.0001), and compression depth (P = 0.003). Those taught conventionally were significantly better at checking for a carotid pulse at both 6 and 12 months (P < 0.0001). These results suggest that training lay persons in basic life support skills using a staged approach leads to overall better skill retention at 6 and 12 months, and has other advantages including a greater willingness to re-attend follow-up classes.

Trials of teaching methods in basic life support (3): comparison of simulated CPR performance after first training and at 6 months, with a note on the value of re-training.

A randomised controlled trial comparing staged teaching of cardiopulmonary resuscitation (CPR) with conventional training provided the additional opportunity to investigate skill acquisition and retention in those attending conventional CPR classes. All subjects were tested immediately after their first instruction period and again at 6-9 months at an unheralded home visit. We were able to assess how far performance was related to poor acquisition of skills and how far it was related to skill decay. Out of 262 subjects who were randomised to receive conventional CPR instruction, 166 were available for home testing at 6-9 months. An invitation to attend for re-training had been accepted by 39 of them. The remaining 127 who attended only a single class comprise the principal study group, with additional comparative observations on the smaller re-trained cohort. Important failings were observed in the acquisition of skills in all modalities tested after the initial instruction. These were particularly marked in skills related to ventilation. Immediately after a class, 68% of trainees performed an effective check of breathing, but only 33% opened the airway as taught and no more than 18% provided an ideal ventilation volume. The technique of chest compression was also less than ideal. Although 80% of subjects placed their hands in an acceptable position, compression to an adequate depth and an adequate rate of compression were achieved by 54 and 63%, respectively. Seventy-eight percent demonstrated a careful approach, and 46% remembered to call for help. A carotid pulse check was simulated by 61% of trainees. When tested 6-9 months later, skill deterioration from this baseline was observed in all modalities tested except for the ventilation volume. The skill decay was significant (P<0.05) for the careful approach, performing an effective breathing check, the carotid pulse check, placing the hands in an acceptable position for chest compression, and compressing at an optimal rate. The minority who attended for re-training showed a trend to protection against skill decay for seven of the ten variables, compared with those who had attended only one training session. This improvement was significant for only two of them, but all were relatively small with limited practical value. Many who attend conventional CPR classes fail to acquire the necessary skills, and the skills that are acquired decline appreciably over the subsequent 6-9 months. The value of conventional re-training was modest in this study of community volunteers.

Effects of prehospital 12-lead ECG on processes of care and mortality in acute coronary syndrome: a linked cohort study from the Myocardial Ischaemia National Audit Project.

OBJECTIVE: To describe patterns of prehospital ECG (PHECG) use and determine its association with processes and outcomes of care in patients with ST-elevation myocardial infarction (STEMI) and non-STEMI. METHODS: Population-based linked cohort study of a national myocardial infarction registry. RESULTS: 288 990 patients were admitted to hospitals via emergency medical services (EMS) between 1 January 2005 and 31 December 2009. PHECG use increased overall (51% vs 64%, adjusted OR (aOR) 2.17, 95% CI 2.12 to 2.22), and in STEMI (64% vs 79%, aOR 2.34, 95% CI 2.25 to 2.44). Patients who received PHECG were younger (71 years vs 74 years, P<0.0001); and less likely to be female (33.1% vs 40.3%, OR 0.87, 95% CI 0.86 to 0.89), or to have comorbidities than those who did not. For STEMI, reperfusion was more frequent in those having PHECG (83.5% vs 74.4%, p<0.0001). PHECG was associated with more primary percutaneous coronary intervention patients achieving call-to-balloon time <90 min (27.9% vs 21.4%, aOR 1.38, 95% CI 1.24 to 1.54) and more patients who received fibrinolytic therapy achieving door-to-needle time <30 min (90.6% vs 83.7%, aOR 2.13, 95% CI 1.91 to 2.38). Patients with PHECG exhibited significantly lower 30-day mortality rates than those who did not (7.4% vs 8.2%, aOR 0.94, 95% CI 0.91 to 0.96). CONCLUSIONS: Findings from this national MI registry demonstrate a survival advantage in STEMI and non-STEMI patients when PHECG was used.