Observed survival benefit of mild therapeutic hypothermia reanalysing the Circulation Improving Resuscitation Care trial.

BACKGROUND: Mild therapeutic hypothermia is argued being beneficial for outcome after cardiac arrest. MATERIALS AND METHODS: Retrospective analysis of Circulation Improving Resuscitation Care (CIRC) trial data to assess if therapeutic cooling to 33 ± 1 °C core temperature had an association with survival. Of 4231 adult, out-of-hospital cardiac arrests of presumed cardiac origin initially enrolled, eligibility criteria for therapeutic hypothermia were met by 1812. Logistic regression was undertaken in a stepwise fashion to account for the impact on outcome of each significant difference and for the variable of interest between the groups. RESULTS: Out-of- and in-hospital cooled were 263 (15%), only after admission cooled were 230 (13%) and not cooled were 357 (20%) patients. The group cooled out of- and in hospital had 98 (37%) survivors as compared to the groups cooled in hospital only [80 (35%)] and of those not cooled [68 (19%)]. After adjusting for known covariates (sex, age, witnessed cardiac arrest, no- and low-flow time, shockable initial rhythm, random allocation, bystander cardiopulmonary resuscitation and percutaneous coronary intervention), the odds ratio for survival comparing no cooling to out-of- plus in-hospital cooling was 0·53 [95% confidence interval (CI): 0·46-0·61, P < 0·001], and comparing to in-hospital cooling only was 0·67 (95% CI: 0·50-0·89, P = 0·006). CONCLUSION: Mild therapeutic hypothermia initiated out of hospital and/or in hospital was associated with improved survival within this secondary analysis of the CIRC cohort compared to no therapeutic hypothermia.

Exposure to carbon monoxide for patients and providers in an urban emergency medical service.

BACKGROUND: Carbon monoxide (CO) poisoning poses danger to both patients and emergency medical services (EMS) personnel, as its symptoms are nonspecific and EMS is currently not equipped to detect CO in ambient air. OBJECTIVE: We aimed to assess the degree of non-fire-related CO exposure at the high-volume EMS system of a city with 2 million inhabitants. METHODS: The EMS system was equipped with handheld CO detectors (Dräger Pac 3500), which were added to EMS standard backpacks and had to be carried to the patient at all times. During a period of one year, all alarms by those devices were recorded, sources of CO were confirmed by the fire department, and hospital follow-up was conducted for both patients and exposed EMS staff. RESULTS: During the study period, there were 40 alarms, including two false alarms. Alarms occurred during the whole year, with a peak during the winter months. The median ambient CO concentration was 167 parts per million; gas heating systems were the main source of CO. One hundred ten patients and 108 EMS personnel were exposed. One hundred fifteen persons, including 22 EMS staff, had to be hospitalized, which represents one out of 1,000 total EMS patients. CONCLUSIONS: Carbon monoxide poisoning was found to be a significant matter for a high-volume EMS system. Handheld CO detectors helped in identifying those cases. Key words: carbon monoxide; emergency care, prehospital; equipment and supplies; poisoning.

Randomized placebo controlled trial of furosemide on subjective perception of dyspnoea in patients with pulmonary oedema because of hypertensive crisis.

BACKGROUND: To compare the administration of furosemide with placebo on the subjective perception of dyspnoea in patients with acute pulmonary oedema because of hypertensive crisis. Design Randomized, controlled and double-blinded clinical trial. SETTING: Municipal emergency medical service system and university-based emergency department. PARTICIPANTS: Fifty-nine patients with pulmonary oedema because of hypertensive crisis. INTERVENTIONS: Additional to administration of oxygen, morphine-hydrochloride and urapidil until the systolic blood pressure was below 160mmHg, the patients were randomized to receive furosemide 80mg IV bolus (furosemide group) or saline placebo (placebo group). MAIN OUTCOME MEASURES: The primary outcome was the subjective perception of dyspnoea as measured with a modified BORG scale at one hour after randomization. Secondary outcome parameters were the subjective perception of dyspnoea of patients as measured with a modified BORG scale and a visual analogue scale at 2, 3 and 6h after randomization of the patient; course of the systolic arterial pressure and peripheral oxygen saturation and lactate at admission and at 6h after admission. RESULTS: In 25 patients in the furosemide group and in 28 patients in the placebo group, a BORG score could be obtained. There was no statistically significant difference in the severity of dyspnoea at one hour after randomization (P=0·40). The median BORG score at 1h after randomization in the furosemide group was 3 (IQR 2 to 4) compared to 3 (IQR 2 to 7) in the placebo group (P=0·40). Those patients who were randomized to the placebo group needed higher doses of urapidil at 20min after randomization. There were no significant differences in the rate of adverse events, nonfatal cardiac arrests or death between the two groups. CONCLUSIONS: The subjective perception of dyspnoea in patients with hypertensive pulmonary oedema was not influenced by the application of a loop-diuretic. Therefore, additional furosemide therapy needs to be scrutinized in the therapy of these patients.

Comparison of two new generation pulse oximeters during emergency ambulance transportation.

OBJECTIVES: We wanted to test whether there is a difference between the total number and duration of malfunctions and a correlation between the oxygen saturation and pulse rate values of two new generation pulse oximeters (Masimo 'Radical 7' and Nellcor 'N 600') during emergency ambulance transportation. METHODS: Patients were monitored with two pulse oximeters ('Radical 7' and 'N 600') on different randomly selected fingers of the same hand during transportation. Data of both devices were recorded continuously by a laptop computer. RESULTS: Fifty-two patients with signs of peripheral vasoconstriction (including 22 patients with a blood pressure ≤100/60) were included. There were 0.21 ± 0.72 (0-4) malfunctions per patient lasting for a mean 113.55 ± 272.55 s in the 'Radical 7' and 0.13 ± 0.49 (0-3) malfunctions per patient with a mean duration of 301.0 ± 426.58 s in the 'N 600'. Oxygen saturation and pulse rate values correlated significantly [r² = 0.9608 (SpO2), r² = 0.9608 (pulse rate)] between the devices and showed a bias of -0.177770 (SpO2) and 0.310883 (pulse rate) with a standard deviation of 1.68367 (SpO2) and 4.46532 (pulse rate) in a Bland-Altman test. CONCLUSION: Although number and duration of malfunctions did not differ significantly between the devices, they showed a very low number of malfunctions even in hypotensive patients with peripheral vasoconstriction. Oxygen saturation correlated significantly in the two devices investigated at 49.409 time points. In addition, pulse rate also correlated significantly.

Physical strain on advanced life support providers in different out of hospital environments.

OBJECTIVES: To examine to what extent the type of emergency medical transportation influences the physical response of advanced life support providers. BACKGROUND: Providing external chest compression during resuscitation is physically exhausting. If the decision is made to bring the patient to a hospital undergoing resuscitation procedures, there are usually two options for transportation: ambulance vehicles or helicopters. There should be discussion on deciding which means of transportation should be preferred, because there is evidence that the quality of rescuers performance influences patient's outcome. METHODS: The study was a randomised crossover trial comparing physical strain on 11 European Resuscitation Council (ERC) approved healthcare professionals during external chest compression in different environments: (a) moving ambulance vehicle vs. (b) flying helicopter, and both compared to (c) staying at the scene (control). MAIN OUTCOME MEASURES: Difference in heart rate to systolic blood pressure ratio after 8 min of external chest compression. Secondary outcomes were BORG-rate of perceived exertion scale, blood pressure, serum lactate, and a Nine Hole Peg Test. RESULTS: Mean heart rate to systolic blood pressure ratio was 0.89+/-0.21 in the ambulance vehicle compared to 1.01+/-0.21 in the flying helicopter (p=0.04) There were no significant differences in the secondary outcome parameters. Perceived exertion increased by resuscitation time in all groups. CONCLUSION: External chest compression CPR is possible in a flying helicopter as it is in a moving ambulance vehicle. There is no clinical relevant difference in physical strain during ALS between a flying helicopter and a moving ambulance car. As would be expected, the exertion increases with duration of CPR.

Results from Austria's nationwide public access defibrillation (ANPAD) programme collected over 2 years.

AIM OF THE STUDY: To analyse 2 years of experience after introducing automated external defibrillators (AED) all over Austria. MATERIALS AND METHODS: This observational study evaluated the number of privately purchased devices and the rate of local bystander-triggered AED deployments from November 2002 to December 2004. As outcome measurements, the hospital discharge rate and neurological condition were recorded. Arrival times of the emergency medical service (EMS) on scene and the time intervals until shock decisions were made were calculated. Shock decisions were verified according to ECG downloads. Results were compared with historical data if applicable. RESULTS: During the study period, 1865 devices were installed. Seventy-three AED deployments were recorded. Eleven cases were excluded from the study because bystanders were part of the local EMS. Seventeen out of the remaining 62 (27%) compared to a historical 27 out of 623 (4.3%) individuals were discharged alive from hospital. Fourteen out of 26 (54%) patients who were found with a shockable rhythm survived to hospital discharge. Fifteen of our patients survived in good neurological condition (CPC I and II), two suffered from severe neurological deficit (CPC III and IV) and 45 people died. The median "call-to-AED advice interval" was 3.5 min (IQR 2-6 min; N=24). In two cases, the AED made inappropriate decisions because of artefacts. CONCLUSIONS: Compared to historical data, short 'intervals to shock' delivery and the frequent start of basic life support resulted in an increased hospital discharge rate in good neurological condition. Despite the relatively high number of installed devices, the number of patients reached remained small.

Implementation of guidelines improves the standard of care: the Viennese registry on reperfusion strategies in ST-elevation myocardial infarction (Vienna STEMI registry).

BACKGROUND: The purpose of this study was to determine whether implementation of recent guidelines improves in-hospital mortality from acute ST-elevation myocardial infarction (STEMI) in a metropolitan area. METHODS AND RESULTS: We organized a network that consisted of the Viennese Ambulance Systems, which is responsible for diagnosis and triage of patients with acute STEMI, and 5 high-volume interventional cardiology departments to expand the performance of primary percutaneous catheter intervention (PPCI) and to use the fastest available reperfusion strategy in STEMI of short duration (2 to 3 hours from onset of symptoms), either PPCI or thrombolytic therapy (TT; prehospital or in-hospital), respectively. Implementation of guidelines resulted in increased numbers of patients receiving 1 of the 2 reperfusion strategies (from 66% to 86.6%). Accordingly, the proportion of patients not receiving reperfusion therapy dropped from 34% to 13.4%, respectively. PPCI usage increased from 16% to almost 60%, whereas the use of TT decreased from 50.5% to 26.7% in the participating centers. As a consequence, in-hospital mortality decreased from 16% before establishment of the network to 9.5%, including patients not receiving reperfusion therapy. Whereas PPCI and TT demonstrated comparable in-hospital mortality rates when initiated within 2 to 3 hours from onset of symptoms, PPCI was more effective in acute STEMI of >3 but <12 hours' duration. CONCLUSIONS: Implementation of recent guidelines for the treatment of acute STEMI by the organization of a cooperating network within a large metropolitan area was associated with a significant improvement in clinical outcomes.

Quality of closed chest compression in ambulance vehicles, flying helicopters and at the scene.

CONTEXT: Transport of patients during resuscitation is a critical procedure. In both, ambulances and helicopters the quality of resuscitation is potentially hampered due to the movement of the vehicle and confined space. To date, however, no direct comparison of the quality of resuscitation at the scene, during a helicopter flight and in a moving ambulance has been made. OBJECTIVE: Direct comparison of the quality of resuscitation at the scene, during a helicopter flight and in a moving ambulance. DESIGN: The study was performed in July 2005 as a randomised cross-over trial comparing different environments for resuscitation. SETTING: Medical University of Vienna. PARTICIPANTS: Eleven European Resuscitation Council (ERC) approved health care professionals. INTERVENTIONS: Interventions during resuscitation: (a) in a moving ambulance, (b) in a flying helicopter, were compared to those staying at the (c) scene (control). Each participant performed resuscitation in all three environments. MAIN OUTCOME MEASURES: Quality of chest compression during resuscitation. RESULTS: Compared to resuscitation at the scene, efficiency of chest compressions during a helicopter flight was 86% and 95% in the moving ambulance 95%. There were no differences in secondary outcomes (time without chest compression, total number of incorrect hand position relative to total compressions, and total number of incorrect pressure release relative to total compressions). CONCLUSIONS: Resuscitation during transport is feasible and relatively efficient. There is some difference between the environments, but there is no relevant difference between helicopters and ambulances regarding the effectiveness of CPR.

Safety and feasibility of the RhinoChill immediate transnasal evaporative cooling device during out-of-hospital cardiopulmonary resuscitation: A single-center, observational study.

We investigated feasibility and safety of the RhinoChill (RC) transnasal cooling system initiated before achieving a protected airway during cardiopulmonary resuscitation (CPR) in a prehospital setting.In out-of-hospital cardiac arrest (OHCA), transnasal evaporative cooling was initiated during CPR, before a protected airway was established and continued until either the patient was declared dead, standard institutional systemic cooling methods were implemented or cooling supply was empty. Patients were monitored throughout the hypothermia period until either death or hospital discharge. Clinical assessments and relevant adverse events (AEs) were documented over this period of time.In total 21 patients were included. Four were excluded due to user errors or meeting exclusion criteria. Finally, 17 patients (f = 6; mean age 65.5 years, CI95%: 57.7-73.4) were analyzed. Device-related AEs, like epistaxis or nose whitening, occurred in 2 patients. They were mild and had no consequence on the patient's outcome. According to the field reports of the emergency medical services (EMS) personnel, no severe technical problems occurred by using the RC device that led to a delay or the impairment of quality of the CPR.Early application of the RC device, during OHCA is feasible, safe, easy to handle, and does not delay or hinder CPR, or establishment of a secure intubation. For efficacy and further safety data additional studies will be needed.

Manual vs. integrated automatic load-distributing band CPR with equal survival after out of hospital cardiac arrest. The randomized CIRC trial.

OBJECTIVE: To compare integrated automated load distributing band CPR (iA-CPR) with high-quality manual CPR (M-CPR) to determine equivalence, superiority, or inferiority in survival to hospital discharge. METHODS: Between March 5, 2009 and January 11, 2011 a randomized, unblinded, controlled group sequential trial of adult out-of-hospital cardiac arrests of presumed cardiac origin was conducted at three US and two European sites. After EMS providers initiated manual compressions patients were randomized to receive either iA-CPR or M-CPR. Patient follow-up was until all patients were discharged alive or died. The primary outcome, survival to hospital discharge, was analyzed adjusting for covariates, (age, witnessed arrest, initial cardiac rhythm, enrollment site) and interim analyses. CPR quality and protocol adherence were monitored (CPR fraction) electronically throughout the trial. RESULTS: Of 4753 randomized patients, 522 (11.0%) met post enrollment exclusion criteria. Therefore, 2099 (49.6%) received iA-CPR and 2132 (50.4%) M-CPR. Sustained ROSC (emergency department admittance), 24h survival and hospital discharge (unknown for 12 cases) for iA-CPR compared to M-CPR were 600 (28.6%) vs. 689 (32.3%), 456 (21.8%) vs. 532 (25.0%), 196 (9.4%) vs. 233 (11.0%) patients, respectively. The adjusted odds ratio of survival to hospital discharge for iA-CPR compared to M-CPR, was 1.06 (95% CI 0.83-1.37), meeting the criteria for equivalence. The 20 min CPR fraction was 80.4% for iA-CPR and 80.2% for M-CPR. CONCLUSION: Compared to high-quality M-CPR, iA-CPR resulted in statistically equivalent survival to hospital discharge.

Strategic target temperature management in myocardial infarction--a feasibility trial.

OBJECTIVE: The purpose of this study was to demonstrate the feasibility of a combined cooling strategy started out of hospital as an adjunctive to percutaneous coronary intervention (PCI) in the treatment of ST-elevation acute coronary syndrome (STE-ACS). DESIGN: Non-randomised, single-centre feasibility trial. SETTING: Department of emergency medicine of a tertiary-care facility, Medical University of Vienna, Vienna, Austria. In cooperation with the Municipal ambulance service of the city of Vienna. PATIENTS: Consecutive patients with STE-ACS presenting to the emergency medical service within 6 h after symptom onset. INTERVENTIONS: Cooling was initiated with surface cooling pads in the out-of-hospital setting, followed by the administration of 1000-2000 mL of cold saline at hospital arrival and completed by endovascular cooling in the catheterisation laboratory. MAIN OUTCOME MEASURES: Feasibility of lowering core temperature below 35.0°C prior to immediately performed revascularisation. Safety and tolerability of the cooling procedure. RESULTS: In enrolled 19 patients (one woman, median age 51 years (IQR 45-59)), symptom onset to first medical contact (FMC) was 45 min (IQR 31-85). A core temperature below 35.0°C at reperfusion of the culprit lesion was achieved in 11 patients (78%) within 100 min (IQR 90-111) after FMC without any cooling-related serious adverse event. Temperature could be lowered from baseline 36.4°C (IQR 36.2-36.5°C) to 34.4°C (IQR 34.1-35.0°C) at the time of reperfusion. CONCLUSIONS: With limitations an immediate out-of-hospital therapeutic hypothermia strategy was feasible and safe in patients with STE-ACS undergoing primary PCI. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov/ct2/show/NCT01864343; clinical trials unique identifier: NCT01864343.

Out of hospital cardiac arrest in Vienna: incidence and outcome.

AIM OF THE STUDY: To determine the incidence of out-of-hospital cardiac arrest and the survival rate of those patients who received CPR in the city of Vienna. METHODS: A cohort of patients with out-of-hospital cardiac arrests and who were treated by the Vienna Ambulance Service between January 1, 2009, and December 31, 2010, were followed up until either death or hospital discharge. The associations of survival and neurological outcome with their potential predictors were analysed using simple logistic regression models. Odds ratios were estimated for each factor. RESULTS: During the observation period, a total of 7030 (206.8/100,000 inhabitants/year) patients without signs of circulation were assessed by teams of the Vienna Ambulance Service, and 1448 adult patients were resuscitated by emergency medical service personnel. A sustained return of spontaneous circulation was reported in 361 (24.9%) of the treated patients, and in all 479 (33.0%) of the patients were taken to the emergency department. A total of 164 (11.3%) of the patients were discharged from the hospital alive, and 126 (8.7%) of the patients showed cerebral performance categories of 1 or 2 at the time of discharge. Younger age, an arrest in a public area, a witnessed arrest and a shockable rhythm were associated with a higher probability of survival to hospital discharge. CONCLUSION: Survival rates for out-of-hospital cardiac arrests remain low. Efforts should be focused on rapidly initiating basic life support, early defibrillation, and high-quality CPR by emergency medical services and state-of-the art post-resuscitation care.

Randomized crossover trial comparing physical strain on advanced life support providers during transportation using real-time automated feedback.

BACKGROUND: Feedback devices provide verbal and visual real-time information on cardiopulmonary resuscitation (CPR) quality. Feedback devices can improve the quality of CPR during transportation. It remains unclear if feedback has an effect on the physical strain felt by providers during ongoing CPR. OBJECTIVES: The objective was to assess the influence of real-time automated feedback on physical strain of rescuers during ongoing chest compressions in different means of transportation. METHODS: The study was a randomized crossover trial comparing physical strain on advanced life support (ALS) providers during chest compressions using real-time automated feedback in different transport environments: 1) a moving ambulance and 2) a flying helicopter. The authors measured objective and subjective measures of physical strain and calculated the difference in the rate pressure product (RPP) after 8 minutes of external chest compressions. RESULTS: There was no difference in the RPP (mean intraindividual difference = 21; 95% confidence interval [CI] = -1,438 to 1,480; p = 0.98) between using the feedback device versus no feedback. There was no significant interaction of vehicle type on the effect of feedback on the RPP. Feedback resulted in a significant mean perceived exertion reduction of a Borg scale score by 0.89 points (95% CI = 0.42 to 1.35; p < 0.001). For systolic and diastolic blood pressure, for serum lactate concentrations, and for the modified Nine Hole Peg Test (NHPT; measurement of fine motor skills), we found no statistically significant differences. CONCLUSIONS: Feedback devices for CPR during transportation do not have an effect on objective components of physical strain, but decrease perceived exertion in experienced rescuers in an experimental setting.

Design of the Circulation Improving Resuscitation Care (CIRC) Trial: a new state of the art design for out-of-hospital cardiac arrest research.

PURPOSE: Mechanical chest compression devices, such as the AutoPulse(®), have been developed to overcome problems associated with manual CPR (M-CPR). Animal and human studies have shown that AutoPulse CPR improves hemodynamic parameters over M-CPR. However, human studies conducted in the prehospital setting have conflicting results as to the AutoPulse's efficacy in improving survival. The Circulation Improving Resuscitation Care (CIRC) Trial is designed to evaluate the effectiveness of integrated AutoPulse-CPR (iA-CPR) (i.e., M-CPR followed by AutoPulse(®)-CPR) in a randomized controlled trial that addresses methodological issues that may have influenced the results of previous studies. METHODS: This paper describes the methodology of the CIRC trial. RESULTS: Unlike previous trials the CIRC trial studies iA-CPR where emphasis is placed on reducing "hands-off" time. The trial has six unique features: (1) training of all EMS providers in a standardized deployment strategy that reduces hands-off time and continuous monitoring for protocol compliance. (2) A pre-trial simulation study of provider compliance with the trial protocol. (3) Three distinct study phases (in-field training, run-in, and statistical inclusion) to minimize the Hawthorne effect and other biases. (4) Monitoring of the CPR process using either transthoracic impedance or accelerometer data. (5) Randomization at the subject level after the decision to resuscitate is made to reduce selection bias. (6) Use of the Group Sequential Double Triangular Test with sufficient power to determine superiority, inferiority, or equivalence. CONCLUSION: This unique, large, multicenter study comparing the effectiveness of iA-CPR to M-CPR will contribute to the science of the treatment of out-of-hospital cardiac arrest as well as to the design of future trials.

Quality of closed chest compression on a manikin in ambulance vehicles and flying helicopters with a real time automated feedback.

CONTEXT: Automated verbal and visual feedback improves quality of resuscitation in out-of-hospital cardiac arrest and was proven to increase short-term survival. Quality of resuscitation may be hampered in more difficult situations like emergency transportation. Currently there is no evidence if feedback devices can improve resuscitation quality during different modes of transportation. OBJECTIVE: To assess the effect of real time automated feedback on the quality of resuscitation in an emergency transportation setting. DESIGN: Randomised cross-over trial. SETTING: Medical University of Vienna, Vienna Municipal Ambulance Service and Helicopter Emergency Medical Service Unit (Christophorus Flugrettungsverein) in September 2007. PARTICIPANTS: European Resuscitation Council (ERC) certified health care professionals performing CPR in a flying helicopter and in a moving ambulance vehicle on a manikin with human-like chest properties. INTERVENTIONS: CPR sessions, with real time automated feedback as the intervention and standard CPR without feedback as control. MAIN OUTCOME MEASURES: Quality of chest compression during resuscitation. RESULTS: Feedback resulted in less deviation from ideal compression rate 100 min(-1) (9+/-9 min(-1), p<0.0001) with this effect becoming steadily larger over time. Applied work was less in the feedback group compared to controls (373+/-448 cm x compression; p<0.001). Feedback did not influence ideal compression depth significantly. There was some indication of a learning effect of the feedback device. CONCLUSIONS: Real time automated feedback improves certain aspects of CPR quality in flying helicopters and moving ambulance vehicles. The effect of feedback guidance was most pronounced for chest compression rate.

Out-of-hospital surface cooling to induce mild hypothermia in human cardiac arrest: a feasibility trial.

AIM: The earliest initiation of mild hypothermia after resuscitation from cardiac arrest is crucial. This study aimed to evaluate the feasibility and safety of out-of-hospital surface cooling in such cases. METHODS: Cooling pads stored below 0 degrees C in the ambulance were applied as soon as possible after restoration of spontaneous circulation in the out-of-hospital setting. This continued in the emergency department until an oesophageal temperature of 34 degrees C was reached, when the pads were removed. A target temperature of 33 degrees C was maintained for 24 h. Results are given as median and interquartile range. RESULTS: From September 2006 to January 2007, 15 victims of cardiac arrest were included. Cooling was initiated at 12 (8.5-15) min after restoration of spontaneous circulation. Oesophageal temperatures decreased from 36.6 (36.2-36.6) degrees C to 33 degrees C within 70 (55-106) min. Hospital admission was at 45 (34-52) min, with oesophageal temperatures of 35.4 (34.6-35.9) degrees C; the target 33 degrees C was achieved 50 (29-82) min after admission. No skin lesions were observed. CONCLUSION: Non-invasive surface cooling immediately after resuscitation from cardiac arrest, in the out-of-hospital setting, proved to be feasible, fast and safe. Whether early cooling will improve neurological outcome needs to be determined in future studies.