The 1998 European Resuscitation Council guidelines for adult advanced life support: A statement from the Working Group on Advanced Life Support, and approved by the executive committee

Drug routes in out-of-hospital cardiac arrest: A summary of current evidence

Recent evidence showing the clinical effectiveness of drug therapy in cardiac arrest has led to renewed interest in the optimal route for drug administration in adult out-of-hospital cardiac arrest. Current resuscitation guidelines support use of the intravenous route for intra-arrest drug delivery, with the intraosseous route reserved for patients in whom intravenous access cannot be established. We sought to evaluate current evidence on drug route for administration of cardiac arrest drugs, with a specific focus on the intravenous and intraosseous route. We identified relevant animal, manikin, and human studies through targeted searches of MEDLINE in June 2022. Across pre-hospital systems, there is wide variation in use of the intraosseous route. Early administration of cardiac arrest drugs is associated with improved patient outcomes. Challenges in obtaining intravenous access mean that the intraosseous access may facilitate earlier drug administration. However, time from administration to the central circulation is unclear with pharmacokinetic data limited mainly to animal studies. Observational studies comparing the effect of intravenous and intraosseous drug administration on patient outcomes are challenging to interpret because of resuscitation time bias and other confounders. To date, no randomised controlled trial has directly compared the effect on patient outcomes of intraosseous compared with intravenous drug administration in cardiac arrest. The International Liaison Committee on Resuscitation has described the urgent need for randomised controlled trials comparing the intravenous and intraosseous route in adult out-of-hospital cardiac arrest. Ongoing clinical trials will directly address this knowledge gap.

Use of a novel pedal-operated compressor is non-inferior to the use of a standard hand-compressed bag-valve mask

BACKGROUND

The standard bag-valve mask (BVM) used universally requires that a single healthcare practitioner affix the mask to the face with 1 hand while compressing a self-inflating bag with the second hand. Studies have demonstrated that creating a 2-handed seal (with 2 healthcare practitioners) is superior. Our study aims to assess the efficacy of a novel single-practitioner BVM device that uses a foot pedal as the bag compressor, allowing both hands to be available for the seal to facilitate delivery of appropriate tidal volumes during single-practitioner resuscitation.

METHODS

This was a prospective, randomized, cross-over study. Participants with various BVM ventilation experience performed 2 minutes of metronome-guided BVM ventilation using a standard BVM and the pedal-operated compressor on a high-fidelity simulation mannequin. Analysis examining differences in mean tidal volume delivered was conducted using a regression model that adjusted for covariates. A secondary analysis using a series of Wilcoxon tests was conducted to compare differences in the additional out-of-range sensed breaths metrics to compare differences by prior BVM ventilation experience.

RESULTS

A total of 58 subjects participated. The pedal-operated compressor unadjusted mean tidal volume delivered was 446.5 mL (95% confidence interval [CI], 425.9-467.1) compared with 340.6 mL (95% CI, 312.2-369.0) by standard BVM (mean change, 105.9 mL [95% CI, 71.2-140.6]; P < .001). When modeling a generalized estimation equation regression model, standard BVM ventilation provided a mean difference of 105.9 mL less than pedal-operated compressor ventilation after adjusting for covariates (P = 0.01). For the secondary outcome, the pedal-operated compressor did have a significantly lower median number of out-of-range breaths (median, 3; interquartile range [IQR], 1-11.5) compared with the standard device (median, 13.5; IQR, 6-19; P < 0.001).

CONCLUSIONS

Use of a novel pedal-operated compressor may allow a single healthcare practitioner, regardless of prior experience, to deliver consistent, appropriate tidal volumes with more ease compared with the standard BVM during manual respiratory resuscitation.

[Executive summary]

Die Leitlinien des European Resuscitation Council 2021 basieren auf einer Reihe systematischer Übersichtsarbeiten, Scoping-Reviews und Aktualisierungen der Evidenz des International Liaison Committee on Resuscitation und stellen die aktuellsten evidenzbasierten Leitlinien für die Praxis der Wiederbelebung in ganz Europa dar. Die Leitlinien umfassen die Epidemiologie des Kreislaufstillstands, die Rolle, die Systeme bei der Rettung von Menschenleben spielen, die Basismaßnahmen der Wiederbelebung Erwachsener, die erweiterten Reanimationsmaßnahmen bei Erwachsenen, die Wiederbelebung unter besonderen Umständen, die Postreanimationsbehandlung, die Erste Hilfe, die Versorgung und Reanimation von Neugeborenen, die lebensrettenden Maßnahmen bei Kindern, die Ethik und die Ausbildung.

European Resuscitation Council Guidelines 2021: Executive summary

Informed by a series of systematic reviews, scoping reviews and evidence updates from the International Liaison Committee on Resuscitation, the 2021 European Resuscitation Council Guidelines present the most up to date evidence-based guidelines for the practice of resuscitation across Europe. The guidelines cover the epidemiology of cardiac arrest; the role that systems play in saving lives, adult basic life support, adult advanced life support, resuscitation in special circumstances, post resuscitation care, first aid, neonatal life support, paediatric life support, ethics and education.

Can EMS Providers Provide Appropriate Tidal Volumes in a Simulated Adult-sized Patient with a Pediatric-sized Bag-Valve-Mask?

INTRODUCTION

In the prehospital setting, Emergency Medical Services (EMS) professionals rely on providing positive pressure ventilation with a bag-valve-mask (BVM). Multiple emergency medicine and critical care studies have shown that lung-protective ventilation protocols reduce morbidity and mortality. Our primary objective was to determine if a group of EMS professionals could provide ventilations with a smaller BVM that would be sufficient to ventilate patients. Secondary objectives included 1) if the pediatric bag provided volumes similar to lung-protective ventilation in the hospital setting and 2) compare volumes provided to the patient depending on the type of airway (mask, King tube, and intubation).

METHODS

Using a patient simulator of a head and thorax that was able to record respiratory rate, tidal volume, peak pressure, and minute volume via a laptop computer, participants were asked to ventilate the simulator during six 1-minute ventilation tests. The first scenario was BVM ventilation with an oropharyngeal airway in place ventilating with both an adult- and pediatric-sized BVM, the second scenario had a supraglottic airway and both bags, and the third scenario had an endotracheal tube and both bags. Participants were enrolled in convenience manner while they were on-duty and the research staff was able to travel to their stations. Prior to enrolling, participants were not given any additional training on ventilation skills.

RESULTS

We enrolled 50 providers from a large, busy, urban fire-based EMS agency with 14.96 (SD = 9.92) mean years of experience. Only 1.5% of all breaths delivered with the pediatric BVM during the ventilation scenarios were below the recommended tidal volume. A greater percentage of breaths delivered in the recommended range occurred when the pediatric BVM was used (17.5% vs 5.1%, p < 0.001). Median volumes for each scenario were 570.5mL, 664.0mL, 663.0mL for the pediatric BMV and 796.0mL, 994.5mL, 981.5mL for the adult BVM. In all three categories of airway devices, the pediatric BVM provided lower median tidal volumes (p < 0.001).

CONCLUSION

The study suggests that ventilating an adult patient is possible with a smaller, pediatric-sized BVM. The tidal volumes recorded with the pediatric BVM were more consistent with lung-protective ventilation volumes.

Cardiac arrest due to drowning--changes over time and factors of importance for survival

AIM

To evaluate changes in characteristics and survival over time in out-of-hospital cardiac arrest (OHCA) due to drowning and describe factors of importance for survival.

METHOD

Retrospectively reported and treated drowning cases reported to the Swedish OHCA registry between 1990 and 2012, n=529. The data were clustered into three seven-year intervals for comparisons of changes over time.

RESULTS

There were no changes in age, gender, witnessed status, shockable rhythm or place of OHCA during the time periods. Bystander CPR increased over time, 59% in interval 1992-1998, versus 74% in interval 2006-2012 (p=0.005). There was a decrease in delay between OHCA and calling for the Emergency Medical Service (EMS) over the years, while calling for the EMS to arrival increased in terms of time. Survival to hospital admission appears to have increased over the years (p=0.009), whereas survival to one month did not change significantly over time. In a multivariate analysis, witnessed status, female gender, bystander CPR, place-home and EMS response time were associated with survival to hospital admission. For survival to one month, place, age, shockable rhythm and logarithmised delay from calling for an ambulance to arrival were of significance for survival.

CONCLUSION

In OHCA due to drowning, over a period of 20 years, bystanders have called for help at an earlier stage and administered CPR more frequently in the past few years. Survival to hospital admission has increased, while shockable rhythm and early arrival of the EMS appear to be the most important factors for survival to one month.

The early minutes of in-hospital cardiac arrest: shock or CPR? A population based prospective study

Objectives

In the early minutes of cardiac arrest, timing of defibrillation and cardiopulmonary resuscitation during the basic life support phase (BLS CPR) is debated. Aims of this study were to provide in-hospital incidence and outcome data, and to investigate the relation between outcome and time from collapse to defibrillation, time to BLS CPR, and CPR quality.

Methods

Resuscitation attempts during a 3-year period at St. Olav's University Hospital (960 beds) were prospectively registered. The times between collapse and initiation of BLS CPR, and defibrillation were determined. CPR quality was assessed by the resuscitation team. The relation between these variables and outcome (short term survival and discharge) was explored using non-parametric correlation and logistic regression.

Results

CPR was started in a total of 223 arrests, an incidence of 77 episodes per 1000 beds per year. Return of spontaneous circulation occurred in 40%, and 29 patients (13%) survived to discharge. Median time from collapse to BLS CPR was 1 minute; CPR was judged to be of good quality in half of the episodes. CPR during the first 3 minutes in ventricular fibrillation (VF/VT) was negatively associated with survival, but later proved beneficial. For patients with non-shockable rhythms, we found no association between outcome and time to BLS or CPR quality.

Conclusion

Our findings indicate that defibrillation should have priority during the first 3 minutes of VF/VT. Later, patients benefit from CPR in conjunction with defibrillation. Patients presenting with non-shockable rhythms have a grave prognosis, and the outcome was not associated with time to BLS or CPR quality.

Electrical defibrillation: new technologies

Two-thirds of deaths from coronary disease occur in the pre-hospital phase and are caused by ventricular fibrillation or pulseless ventricular tachycardia, for which electrical defibrillation is the only effective treatment. The time delay between the onset of ventricular fibrillation and the administration of the first defibrillatory shock is the most important determinant for survival. To achieve the earliest defibrillation possible, rescuers others than physicians need to be able to initiate this treatment. The international scientific community strongly supports the concept of early defibrillation in the setting of a strong chain of survival. New technological developments of automated external defibrillators (AEDs) allowed the implementation of defibrillation by the first responding professional rescuer. As a consequence of the technological evolution in implantable defibrillators, much research has also been done on new defibrillation waveforms and alternative energy levels in external defibrillators. After initial animal research, human clinical investigation has shown that initial low energy (150J) nonprogressive (150J-150J-150J) impedance-adjusted biphasic waveform defibrillatory shocks for patients in out-of-hospital ventricular fibrillation are safe, acceptable and clinically effective. Reporting on outcome from cardiac arrest must be as uniform as possible to allow conclusions on performance of emergency medical service systems. The 'Utstein Style' nomenclature is a glossary of terms and a reporting guideline for uniform description of cardiac arrest, resuscitation, the emergency medical service (EMS) system and the outcome. Reports on experiences with AED programmes by traditional and non-traditional professional rescuers support the view that AEDs should not be implemented in EMS systems as an isolated intervention, but that efforts are equally needed to strengthen the other links of the chain of survival. The international scientific community (American Heart Association, International Liaison Committee on Resuscitation and European Resuscitation Council) have issued guidelines for the use of AEDs by EMS providers and first responders, and a universal treatment algorithm is proposed.

Incomplete chest wall decompression: a clinical evaluation of CPR performance by trained laypersons and an assessment of alternative manual chest compression-decompression techniques

BACKGROUND

Complete chest wall recoil improves hemodynamics during CPR by generating relatively negative intrathoracic pressure, which draws venous blood back to the heart, providing cardiac preload prior to the next chest compression.

OBJECTIVE

This study was designed to assess the quality of CPR delivered by trained laypersons and to determine if a change in CPR technique or hand position would improve complete chest wall recoil, while maintaining adequate duty cycle, compression depth, and proper hand position placement. Standard manual CPR and three alternative manual CPR approaches were assessed.

METHODS

This randomized prospective trial was performed on an electronic test manikin. Thirty laypersons (mean age of 40.6 years (range 28-55)), who were trained in CPR within the last 24 months, signed an informed consent and participated in the trial. Subjects performed 3 min of CPR on a Laerdal Skill Reportertrade mark CPR manikin using the Standard Hand Position followed by 3 min of CPR (in random order) using three alternative CPR techniques: (1) Two-Finger Fulcrum Technique - lifting the heel of the hand slightly but completely off the chest during the decompression phase of CPR using the thumb and little finger as a fulcrum; (2) Five-Finger Fulcrum Technique - lifting the heel of the hand slightly but completely off the chest during the decompression phase of CPR using all five fingers as a fulcrum; (3) Hands-Off Technique - lifting the heel and all fingers of the hand slightly but completely off the chest during the decompression phase of CPR. The participants did not know the purpose of the study prior to, or during this investigation.

RESULTS

Adequate compression depth was poor for all hand positions tested and ranged only from 18.6 to 35.7% of all compressions. When compared with the Standard Hand Position, the Hands-Off Technique decreased the mean compression duty cycle from 39.0 +/- 1.0 to 33.5 +/- 1.0%, (P < 0.0001) but achieved the highest rate of complete chest wall recoil (92.5% versus 24.1%, P < 0.0001) and was 46.3 times more likely to provide complete chest wall recoil (OR: 46.3; CI: 16.4-130.3). There were no significant differences in accuracy of hand placement, adequate depth of compression, or perceived discomfort with its use compared with the Standard Hand Position.

CONCLUSIONS

The Hands-Off Technique decreased compression duty cycle but was 46.3 times more likely to provide complete chest wall recoil (OR: 46.3; CI: 16.4-130.3) compared to the Standard Hand Position without differences in accuracy of hand placement, adequate depth of compression, or perceived discomfort with its use. All forms of manual CPR tested (including the Standard Hand Position) in trained laypersons produced an inadequate depth of compression for two-thirds of the time. These data support development and testing of more effective layperson CPR training programmes and more effective means to deliver manual as well as mechanical CPR.

Prospective performance evaluation of emergency medical services for cardiac arrest in Lombardia: is something moving forward?

BACKGROUND

Limited data are available in our region on out-of-hospital treatment of cardiac arrest. The aim of this study is to evaluate whether the changes implemented in the emergency system (i.e. an increased number of basic life support and advance life support crews that were dispatched) produced the expected outcome improvements.

METHODS

(a)

EXPERIMENTAL DESIGN

data were prospectively collected on patients with sudden out-of-hospital cardiac arrest in three emergency dispatch centers for 3 months during two study periods, year 2000 and year 2003, differentiated only by the increase of qualified crews. Outcomes and survival were evaluated at 24 h and 1 month after the event. (b)

SETTING

out-of-hospital treatment. (c)

PATIENTS

352 (174 in the second study period) patients suffering cardiac arrest. (d)

INTERVENTIONS

the study was observational.

RESULTS

We could document, between the two study periods, stable 24 h (12.6 vs 9.1%) and 1 month survival (3.4 vs 5.8%, NS). Nevertheless, arrival time on site was significantly higher in the second period (from 8.3+/-3.3 to 10.1+/-5.4 min, P<0.05).

CONCLUSIONS

The strengthening of only one link of the chain-of-survival did not improve 1 month survival.

When should we thrombolyse patients with pulmonary embolism? A systematic review of the literature

The early mortality in pulmonary embolism (PE) is largely predicted by the associated cardiovascular response, with progressive right ventricular failure, hypotension, shock, and circulatory arrest being associated with increasing mortality. Thrombolysis may improve the prognosis of PE associated with these varying degrees of circulatory collapse, but has no place in the treatment of small emboli with no cardiovascular compromise, as it carries a significant risk of haemorrhage. This review sets out to guide the emergency physician in deciding which patients with PE may benefit from thrombolysis.

Assessment of the success of cardiopulmonary resuscitation attempts performed in a Turkish university hospital

The success rate of cardiopulmonary resuscitation (CPR) may differ from institution to institution, even within different sites in the same institution. A variety of factors may influence the outcome. In this study, we assessed the adequacy of CPR attempts guided by the current standards and aimed to define the factors influencing the outcome following in-hospital cardiac arrest. One hundred and thirty-four patients who required CPR were studied prospectively. Different variables for the CPR performance were recorded using forms designed for this study in the light of the guidelines. In these CPR forms various data including the demographics, history, monitoring, number, composition and experience of the anaesthesiologists, the site of CPR, time of day, the delay before onset of CPR, tracheal intubation, duration of arrest, initial rhythm in ECG monitored patients, management of CPR, drug administration and reversible causes of cardiac arrest were recorded. Our rates of immediate survival, survival at 24 h and survival to discharge 49.3%, 28.5% and 13.4%, respectively. The extent of monitoring prior to arrest, the attendance of one or more experienced anesthesiologists in the CPR team, CPR during office hours, CPR in ICU or operating room, early initiation of CPR and tracheal intubation prior to arrest were found as the factors increasing discharge survival. We conclude that early initiation of CPR with an experienced team in a well-equipped hospital sites increases the discharge survival rate following cardiac arrest.

Drugs and drug administration in extreme environments

Emergency medicine must often cope with harsh climates far below freezing point or high temperatures, and sometimes, an alternative to the normal route of drug administration is necessary. Most of this information is not yet published. Therefore, we summarized the information about these topics for most drugs used in medical emergencies by combining literature research with extensive personal communications with the heads of the drug safety departments of the companies producing these drugs. Most drugs can be used after temperature stress of limited duration. Nevertheless, we recommend replacing them at least once per year or after extreme heat. Knowledge about drugs used in extreme environments will be of increasing importance for medical personnel because in an increasingly mobile society, more and more people, and especially elderly -often with individual medical risks-travel to extreme regions such as tropical or arctic regions or to high altitude, and some of them need medical care during these activities. Because of this increasing need to use drugs in harsh climates (tourism, expeditions, peace corps, military, etc) the actual International Congress of Harmonization recommendations should be added with stability tests at +50 degrees C, freezing and oscillating temperatures, and UV exposure to simulate the storage of the drugs at "outdoor conditions."

Epinephrine and vasopressin during cardiopulmonary resuscitation

Epinephrine (adrenaline) and vasopressin have been by far the most commonly studied vasopressors in experimental cardiac arrest. Despite animal experimental studies suggesting improved outcomes in experimental cardiac arrest, clinical trials of pressor agents have failed to show clear cut benefit from either vasopressin or epinephrine, although few, if any, trials compared pressor agents to a placebo. The action of vasopressors in the heart, particularly beta1-adrenergic stimulation, is associated with adverse cardiac effects including post-resuscitation myocardial dysfunction, worsening ventricular arrhythmias, and increasing myocardial oxygen consumption. Alpha2-adrenergic agonists, in experimental studies, show great promise in improving outcomes in experimental cardiac arrest, but have not been studied in humans. The combination of epinephrine and vasopressin may be effective, but has been incompletely studied. Clinical trials of vasopressor agents, which minimize direct myocardial effects are needed.

[Acute coronary syndrome in the prehospital phase]

Cardiovascular diseases are the number one cause of death in Germany. In 2002 about 70,000 people died of acute myocardial infarction (AMI) and of these 37% died before arrival at hospital which underlines the relevance of adequate prehospital care. The generic term acute coronary syndrome (ACS) was introduced because a single pathomechanism accounts for the different forms and comprises unstable angina pectoris (iAP), non-ST-elevation myocardial infarction (NSTEMI), ST-elevation myocardial infarction (STEMI) and sudden cardiac death (SCD). Characteristic features are retrosternal pain, vegetative symptoms and radiation of pain into the adjoining regions. Further differentiation can only be achieved by the 12-lead ECG, as cardiac-specific enzymes do not play a role in prehospital decisions. Prehospital delays should be avoided, history and physical examination should be brief but focused, vital parameters should be assessed and monitored. Basic treatment for ACS should comprise inhalative oxygen, nitrates, morphine, aspirin and beta-blockers. If STEMI is diagnosed, patients with symptoms <12 h should undergo fibrinolytic therapy unless there is primary percutaneous coronary intervention (PCI) available within 90 min or if contraindicated. Heparin should be given to patients with STEMI depending on the choice of fibrinolytic agent, it otherwise results in a higher risk of bleeding, but in patients with iAP or NSTEMI it reduces mortality. All patients must be accompanied by the emergency physician during transportation and should be brought to a hospital with primary PCI, especially those with complicated ACS. Treatment of complications depends largely on the type, persistence and severity.

Layperson positioning of defibrillation electrodes guided by pictorial instructions

BACKGROUND

Correct positioning of defibrillation electrodes is essential to achieve sufficient transmyocardial current to depolarize a critical mass of myocardium, and thus terminate ventricular fibrillation (VF).

AIM

To evaluate the pictures on the self-adhesive defibrillation electrodes in guiding laypersons to place the electrodes in the recommended position.

METHODS

Defibrillation electrodes from five manufactures (Access Cardio Systems, Schiller, Medtronic, Cardiac Science and Philips) were included in the study and compared with electrodes with a lateral view picture, designed for the study, showing the placement of the apical electrode. A total of 150 laypersons without any experience or training in use of a defibrillator participated in the study. The participants placed randomly selected electrodes on the chest of a resuscitation manikin without any guidance apart from the pictures on the electrodes. The distances of the electrodes from the recommended positions were measured.

RESULTS

The proportion of participants who placed both electrodes within 5 cm from recommended position varied from 8% to 36% with the different electrodes. Usually, the apical electrode was placed too anteriorly. Electrodes placed with help of the lateral instruction picture, (designed for the study), showing the placement of the apical electrode were placed significantly more often within 5 cm than any of the others (64%, 95% confidence interval 44-80, P < 0.05).

CONCLUSIONS

The current practice in designing pictures on the electrodes does not seem to be optimal in showing the recommended position of the apical electrode as recommended by Guidelines 2000. It is suggested that by showing a lateral view in the instructions, success in placing the apical electrodes correctly can be improved.

Incomplete chest wall decompression: a clinical evaluation of CPR performance by EMS personnel and assessment of alternative manual chest compression–decompression techniques

BACKGROUND

Complete chest wall recoil improves hemodynamics during cardiopulmonary resuscitation (CPR) by generating relatively negative intrathoracic pressure and thus draws venous blood back to the heart, providing cardiac preload prior to the next chest compression phase.

OBJECTIVE

Phase I was an observational case series to evaluate the quality of chest wall recoil during CPR performed by emergency medical services (EMS) personnel on patients with an out-of-hospital cardiac arrest. Phase II was designed to assess the quality of CPR delivered by EMS personnel using an electronic test manikin. The goal was to determine if a change in CPR technique or hand position would improve complete chest wall recoil, while maintaining adequate duty cycle, compression depth, and correct hand position placement. Standard manual CPR and three alternative manual CPR approaches were assessed.

METHODS AND RESULTS

Phase I--The clinical observational study was performed by an independent observer noting incomplete chest wall decompression and correlating that observation with electronically measured airway pressures during CPR in adult patients with out-of-hospital cardiac arrest. Rescuers were observed to maintain some residual and continuous pressure on the chest wall during the decompression phase of CPR, preventing full chest wall recoil, at some time during resuscitative efforts in 6 (46%) of 13 consecutive adults (average +/- S.D. age 63 +/-5.8 years). Airway pressures were consistently positive during the decompression phase (>0 mmHg) during those observations. Phase II: This randomized prospective trial was performed on an electronic test manikin. Thirty EMS providers (14 EMT-Basics, 5 EMT-Intermediates, and 11 EMT-Paramedics), with an average age +/- S.D. of 32 +/- 8 years and 6.5 +/- 4.2 years of EMS experience, performed 3 min of CPR on a Laerdal Skill Reporter CPR manikin using the Standard Hand Position followed by 3 min of CPR (in random order) using three alternative CPR techniques: (1) Two-Finger Fulcrum Technique--lifting the heel of the hand slightly but completely off the chest during the decompression phase of CPR using the thumb and little finger as a fulcrum; (2) Five-Finger Fulcrum Technique--lifting the heel of the hand slightly but completely off the chest during the decompression phase of CPR using all five fingers as a fulcrum; and (3) Hands-Off Technique--lifting the heel and all fingers of the hand slightly but completely off the chest during the decompression phase of CPR. These EMS personnel did not know the purpose of the studies prior to or during this investigation. Adequate compression depth was poor for all hand positions tested and ranged only from 29.9 to 48.5% of all compressions. When compared with the Standard Hand Position, the Hands-Off Technique decreased mean compression duty cycle from 46.9 +/- 6.4% to 33.3 +/- 4.6%, (P < 0.0001) but achieved the highest rate of complete chest wall recoil (95.0% versus 16.3%, P < 0.0001) and was 129 times more likely to provide complete chest wall recoil (OR: 129.0; CI: 43.4-382.0). There were no significant differences in accuracy of hand placement, depth of compression, or reported increase in fatigue or discomfort with its use compared with the Standard Hand Position.

CONCLUSIONS

Incomplete chest wall decompression was observed at some time during resuscitative efforts in 6 (46%) of 13 consecutive adult out-of-hospital cardiac arrests. The Hands-Off Technique decreased compression duty cycle but was 129 times more likely to provide complete chest wall recoil (OR: 129.0; CI: 43.4-382.0) compared to the Standard Hand Position without differences in accuracy of hand placement, depth of compression, or reported increase in fatigue or discomfort with its use. All forms of manual CPR tested (including the Standard Hand Position) in professional EMS rescuers using a recording manikin produced an inadequate depth of compression more than half the time. These data support development and testing of more effective means to deliver manual as well as mechanical CPR.

Effects of incomplete chest wall decompression during cardiopulmonary resuscitation on coronary and cerebral perfusion pressures in a porcine model of cardiac arrest

INTRODUCTION

Recent data suggest that generation of negative intrathoracic pressure during the decompression phase of CPR improves hemodynamics, organ perfusion and survival.

HYPOTHESIS

Incomplete chest wall recoil during the decompression phase of standard CPR increases intrathoracic pressure and right atrial pressure, impedes venous return, decreases compression-induced aortic pressures and results in a decrease of mean arterial pressure, coronary and cerebral perfusion pressure.

METHODS

Nine pigs in ventricular fibrillation (VF) for 6 min, were treated with an automated compression/decompression device with a compression rate of 100 min(-1), a depth of 25% of the anterior-posterior diameter, and a compression to ventilation ratio of 15:2 with 100% decompression (standard CPR) for 3 min. Compression was then reduced to 75% of complete decompression for 1 min of CPR and then restored for another 1 min of CPR to 100% full decompression. Coronary perfusion pressure (CPP) was calculated as the diastolic (aortic (Ao)-right atrial (RA) pressure). Cerebral perfusion pressure (CerPP) was calculated multiple ways: (1) the positive area (in mmHg s) between aortic pressure and intracranial pressure (ICP) waveforms, (2) the coincident difference in systolic and diastolic aortic and intracranial pressures (mmHg), and (3) CerPP = MAP--ICP. ANOVA was used for statistical analysis and all values were expressed as mean +/- S.E.M. The power of the study for an alpha level of significance set at 0.05 was >0.90.

RESULTS

With CPR performed with 100%-75%-100% of complete chest wall recoil, respectively, the CPP was 23.3 +/- 1.9, 15.1 +/- 1.6, 16.6 +/- 1.9, p = 0.003; CerPP was: (1) area: 313.8 +/- 104, 89.2 +/- 39, 170.5 +/- 42.9, p = 0.03, (2) systolic aortic minus intracranial pressure difference: 22.8 +/- 3.6, 16.5 +/- 4, 23.7 +/- 4.5, p = n.s., and diastolic pressure difference: 5.7 +/- 3, -2.4 +/- 2.4, 3.2 +/- 2.5, p = 0.04 and (3) mean: 14.3 +/- 3, 7 +/- 2.9, 12.4 +/- 2.9, p = 0.03, diastolic aortic pressure was 28.1 +/- 2.5, 20.7 +/- 1.9, 20.9 +/- 2.1, p = 0.0125; ICP during decompression was 22.8 +/- 1.7, 23 +/- 1.5, 19.7 +/- 1.7, p = n.s. and mean ICP was 37.1 +/- 2.3, 35.5 +/- 2.2, 35.2 +/- 2.4, p = n.s.; RA diastolic pressure 4.8 +/- 1.3, 5.6 +/- 1.2, 4.3 +/- 1.2 p = 0.1; MAP was 52 +/- 2.9, 43.3 +/- 3, 48.3 +/- 2.9, p = 0.04; decompression endotracheal pressure, -0.7 +/- 0.1, -0.3 +/- 0.1, -0.75 +/- 0.1, p = 0.045.

CONCLUSIONS

Incomplete chest wall recoil during the decompression phase of CPR increases endotracheal pressure, impedes venous return and decreases mean arterial pressure, and coronary and cerebral perfusion pressures.

A probabilistic neural network as the predictive classifier of out-of-hospital defibrillation outcomes

INTRODUCTION

Although modern defibrillators are nearly always successful in terminating ventricular fibrillation (VF), multiple defibrillation attempts are usually required to achieve return of spontaneous circulation (ROSC). This is potentially deleterious as cardiopulmonary resuscitation (CPR) must be discontinued during each defibrillation attempt which causes deterioration in the heart muscle and reduces the chance of ROSC from later defibrillation attempts. In this work defibrillation outcomes are predicted prior to electrical shocks using a neural network model to analyse VF time series in an attempt to avoid defibrillation attempts that do not result in ROSC.

METHODS

The 198 pre-shock VF ECG episodes from 83 cardiac arrest patients with defibrillation conversions to different outcomes were selected from the Oslo ambulance service database. A probabilistic neural network model was designed for training and testing with a cross validation method being used for the better generalisation performance.

RESULTS

We achieved an accuracy of 75% in overall prediction with a sensitivity of 84% and a specificity of 65% using VF ECG time series of an order of 1 s in length.

CONCLUSION

Pre-shock VF ECG time series can be classified according to the defibrillation conversion to a return of spontaneous circulation (ROSC) or No-ROSC.

Adherence to guidelines when positioning the defibrillation electrodes

BACKGROUND

Placement of the defibrillation electrodes affects the transmyocardial current and thus the success of a defibrillation attempt. In the international guidelines 2000, the placement of the apical electrode was changed more laterally to the mid-axillary line. Finnish national guidelines, based on the international guidelines, were published in 2002.

OBJECTIVES

The purpose of this study was to determine to what extent health care professionals adhere to the new guidelines when positioning the electrodes.

METHODS

Professionals were recruited from emergency medical services, university hospitals and primary care. Not revealing the purpose of the test, participants were asked to place self-adhesive electrodes on a manikin as they would do in the resuscitation situation and to answer a questionnaire about resuscitation training and familiarity with the guidelines. The distance of electrodes from the recommended position was measured in horizontal and vertical planes.

RESULTS

One-hundred and thirty six professionals participated in the study, and only 25.4% (95% CI 18.5-32.9) of them placed both electrodes within 5 cm from the recommended position. The majority of the participants placed the apical electrode too anteriorly. Of the participants, 36.0% were not aware of the new guidelines. Awareness of the guidelines did not increase the accuracy in electrode placement.

CONCLUSIONS

The publication of the national evidence based resuscitation guidelines did not seem to have influenced the practice of placement of the defibrillation electrodes to any major extent. The correct placement of the electrodes needs be emphasized more in the resuscitation training.

The incidence and severity of cutaneous burns following external DC cardioversion

INTRODUCTION

Cutaneous burns are a common cause of morbidity following direct current (DC) cardioversion, but the incidence and severity have never been quantified.

MATERIALS AND METHODS

Two hours after elective DC cardioversion in 83 sequential patients, we measured skin temperature, erythema index, and minimum sensory and pain detection thresholds at paddle sites and control sites on the contralateral side. Visual analogue pain score (VAS) was recorded at 2 and 24h post-cardioversion.

RESULTS

Values for areas over paddle sites were higher (P < 0.05) than control site for all variables measured at 2h. Eighty-four percent patients experienced some pain and 23% patients experienced moderate to severe pain as assessed by VAS. Burns were greater at the edge than the centre of sternal sites and greater at sternal than apical sites. There were positive correlations between transthoracic impedance (TTI) and total energy delivered (r(2) = 0.048; P = 0.04); total energy and pain at 2 h (r(2) = 0.38; P < 0.0001) and 24 h (r(2) = 0.23; P < 0.0001); and number of shocks and pain at 2 h (r(2) = 0.36; P < 0.0001) and 24 h (r(2) = 0.19; P < 0.0001).

CONCLUSION

Elective DC cardioversion causes burns as measured by skin temperature, erythema index and sensory threshold to sharp touch. Pain experienced is related to the total energy and number of shocks delivered. To reduce burns, operators should apply optimal paddle force equally to both paddles, with the paddles applied so as to provide even contact along their edges. Burns may also be minimised by starting with lower energy shocks.

Comparison of Standard Cardiopulmonary Resuscitation Versus the Combination of Active Compression-Decompression Cardiopulmonary Resuscitation and an Inspiratory Impedance Threshold Device for Out-of-Hospital Cardiac Arrest

BACKGROUND

Active compression-decompression (ACD) CPR combined with an inspiratory impedance threshold device (ITD) improves vital organ blood flow during cardiac arrest. This study compared survival rates with ACD+ITD CPR versus standard manual CPR (S-CPR).

METHODS AND RESULTS

A prospective, controlled trial was performed in Mainz, Germany, in which a 2-tiered emergency response included early defibrillation. Patients with out-of-hospital arrest of presumed cardiac pathogenesis were sequentially randomized to ACD+ITD CPR or S-CPR by the advanced life support team after intubation. Rescuers learned which method of CPR to use at the start of each work shift. The primary end point was 1-hour survival after a witnessed arrest. With ACD+ITD CPR (n=103), return of spontaneous circulation and 1- and 24-hour survival rates were 55%, 51%, and 37% versus 37%, 32%, and 22% with S-CPR (n=107) (P=0.016, 0.006, and 0.033, respectively). One- and 24-hour survival rates in witnessed arrests were 55% and 41% with ACD+ITD CPR versus 33% and 23% in control subjects (P=0.011 and 0.019), respectively. One- and 24-hour survival rates in patients with a witnessed arrest in ventricular fibrillation were 68% and 58% after ACD+ITD CPR versus 27% and 23% after S-CPR (P=0.002 and 0.009), respectively. Patients randomized > or =10 minutes after the call for help to the ACD+ITD CPR had a 3 times higher 1-hour survival rate than control subjects (P=0.002). Hospital discharge rates were 18% after ACD+ITD CPR versus 13% in control subjects (P=0.41). In witnessed arrests, overall neurological function trended higher with ACD+ITD CPR versus control subjects (P=0.07).

CONCLUSIONS

Compared with S-CPR, ACD+ITD CPR significantly improved short-term survival rates for patients with out-of-hospital cardiac arrest. Additional studies are needed to evaluate potential long-term benefits of ACD+ITD CPR.

Major bleeding complications in cardiopulmonary resuscitation: the place of thrombolytic therapy in cardiac arrest due to massive pulmonary embolism

OBJECTIVE

Thrombolytic therapy in patients with massive pulmonary embolism (MPE) and prolonged cardiopulmonary resuscitation (CPR) is subject to debate. This study was performed to determine whether (1) thrombolytic treatment increases the risk of bleeding complications, (2) if the risk of bleeding is influenced by the duration of CPR and if (3) thrombolytic therapy improves outcome.

DESIGN

Retrospective cohort study.

SETTING

Emergency department of a tertiary care university hospital.

PATIENTS AND METHODS

Sixty-six patients with cardiac arrest (CA) due to MPE admitted between July 1993 and December 2001. Thirty-six patients received thrombolysis (TL) and were compared with 30 patients without thrombolytic therapy. Bleeding complications were assessed by clinical evidence or autopsy.

RESULTS

Major bleeding complications appear to occur more frequently in patients treated with thrombolytics (9/36 (25%) vs. 3/30 (10%)) even though the difference was statistically not significant (P=0.15). It appears that CPR duration >10 min has no adverse impact on major bleeding complications. No difference in the rate of major bleeding complications between thrombolyzed patients who had a CPR duration of </=10 or >10 min could be observed (2/8 (25%) vs. 7/28 (25%), P=0.99). In thrombolyzed patients a return of spontaneous circulation could be achieved more frequently (24/36 (67%) vs.13/30 (43%) in controls, P=0.06) and survival after 24 h was higher (19/36 (53%) vs. 7/30 (23%), P=0.01). Survival to discharge was also higher in the TL group (7/36 (19%) vs. 2/30 (7%)), but not statistically significant (P=0.15).

CONCLUSION

Although severe bleeding complications tend to occur more frequently in patients undergoing TL, the benefit of this treatment might outweigh the risk of bleeding.

Common faults in resuscitation equipment--guidelines for checking equipment and drugs used in adult cardiopulmonary resuscitation

Successful advanced life support relies, in part, upon the availability and correct functioning of resuscitation equipment. However, numerous publications report deficiencies and defects in key items of resuscitation equipment, particularly those relating to airway management and defibrillation. Some of these are generic and relate to basic device failure (e.g. intrinsic design faults, manufacturing errors, random component failure), external factors (e.g. power failure, gas supply failure, electromagnetic interference) and human error (notably, inadequate knowledge, lack of experience and training, inadequate checking, insufficient maintenance). However, others are device specific. This paper identifies the common, generic faults that lead to equipment malfunction and recommends the resuscitation equipment essential for successful cardiopulmonary resuscitation. It also describes examples of specific equipment malfunction and makes suggestions for the nature and frequency of resuscitation equipment and drug checks, using a structured, and easy-to-recall list.

Prevention of deterioration of ventricular fibrillation by basic life support during out-of-hospital cardiac arrest

Survival of cardiac arrest is improved by basic life support (BLS). This study investigated the relationship between ventricular fibrillation (VF) characteristics and survival. In a 2-year prospective study out-of-hospital witnessed non-traumatic cardiac arrests were observed. The probabilities of recording VF, asystole or other rhythms in relation to BLS and the time to the rhythm recording were analyzed with logistic regression. Amplitude and baseline crossings of VF were related to survival, using linear regression analysis. In 873 patients, the probability to record VF decreased per minute (OR 0.92, 95%CI 0.89-0.95) and of asystole increased (OR 1.13, 95%CI 1.09-1.18) as time from collapse elapsed. BLS reduced these trends significantly for VF (OR 0.97, 95%CI 0.94-0.99) and asystole (OR 1.09, 95%CI 1.05-1.13). This effect was not observed for other rhythms. The amplitude of VF decreased in time; significantly less for patients who received BLS than for those who did not (p=0.009). Survival significantly decreased with lower amplitude of VF (OR 0.23 per mV, 95%CI 0.07-0.79) and with less baseline crossings (OR 0.80 per baseline crossings per second, 95%CI 0.71-0.91). Our study demonstrated that BLS and VF as initial rhythm, considered being "baseline" predictors in survival models, were proved not independent of each other. The decrease of VF amplitude and increase in prevalence of asystole is slowed significantly by BLS. Predicting survival from VF amplitude and baseline crossings alone is limited.

In-hospital cardiopulmonary resuscitation: organization, management and training in hospitals of different levels of care

BACKGROUND

: During recent years in-hospital cardiopulmonary resuscitation (CPR) management has received much attention. This can be attributed to the Utstein model for in-hospital CPR developed in 1997. The present status of in-hospital resuscitation management in Finnish hospitals is not known. Therefore, a study was designed to describe the organization of training and clinical management of CPR in Finnish hospitals of different levels of care.

METHODS

: In the summer of 2000, we performed a cross-sectional mail survey throughout Finland, including all district, central and university hospitals. The questionnaire outlined in detail in-hospital resuscitation management and training. For analysis the hospitals were divided into primary, secondary and tertiary groups, depending on levels of care.

RESULTS

: Most hospitals (72%) reported having a physician or a nurse in charge of resuscitation management and training. Training in advanced life support was more common among nurses (80%) than among physicians (53%). Surprisingly, a majority of respondents (75%) reported that they felt training in CPR was insufficient. On the general wards and on wards treating cardiac patients, defibrillation was in most cases performed by a physician (91% and 51%, respectively), and less often by a nurse (16% and 31%, respectively). In the secondary and tertiary hospitals cardiac arrest was managed by a cardiac arrest team (53% and 62%, respectively) and in the primary hospitals by the ward physician (56%), anesthesiologist or emergency physician on call (44%). Most hospitals used do-not-resuscitate orders (83%) but only 33% of the hospitals had a unified style of notation. Systematic data collection was practised in 55% of hospitals, predominantly by using a model of their own. Only a few hospitals (11%) used the in-hospital Utstein model.

CONCLUSION

: Our study showed that more attention needs to be paid to CPR management in Finnish hospitals. At present, 25% of hospitals do not have an appointed physician or nurse in charge of organizing CPR management. The study also revealed a lack of regular organized training in resuscitation for physicians. Fifty-five per cent of hospitals practise systematic data collection, but only 11% according to the Utstein template; and without which further quality assurance is difficult.

Recent advances in emergency life support

With additional international input, recent changes in emergency life support are reflected in updated guidelines for Advanced Cardiac Life Support (ACLS) from the American Heart Association and new technology in the arena of vascular access and emergency airway management. These changes will expand nurses' ability to provide advanced levels of care, even in the prehospital situation, and represent a more rigorous evidence-based approach than ever before. As early morbidity and mortality in emergency situations are frequently associated with complications associated with airway management and vascular access, recent development in these areas are reviewed along with evolution in ACLS guidelines.

Survival to discharge following open chest cardiac compression (OCCC). A 4-year retrospective audit in a cardiothoracic specialist centre--Royal Brompton and Harefield NHS Trust, United Kingdom

OBJECTIVE

To review the use of Open Chest Cardiac Compression (OCCC) techniques in postcardiac surgical patients in one specialist cardiothoracic centre in the UK.

METHODS

A 4-year retrospective audit (April 1995--March 1999) of all cardiac arrest victims and resuscitation practice across two specialist cardiothoracic hospitals. Audit outcomes related to initial survival and survival to discharge, arrest rhythm, reasons for resternotomy, surgical procedure prior to resternotomy and time elapsed from original surgery to resternotomy.

RESULTS

Seventy-two patients (adult and paediatric) suffering cardiac arrest received OCCC following cardiac surgery. Thirty-three patients initially survived (46%) and 12 patients survived to discharge (17%).

DISCUSSION AND RECOMMENDATIONS

In the absence of current European Resuscitation Council guidelines, we adopted recommendations for resternotomy to be performed after 5 min of unsuccessful conventional CPR and OCCC initiated. An adapted ERC algorithm incorporating these recommendations can provide much needed direction in postcardiac surgery cardiac arrest victims.

Effect of three emergency pacing modalities on cardiac output in cardiac arrest due to ventricular asystole

Pacing is a well recognised treatment in asystolic arrest with residual p wave activity. This can be achieved by transvenous, transthoracic, or manual external (cardiac percussion) pacing techniques. We report a case of ventricular asystole in which all three pacing modalities were applied, and demonstrate their relative effectiveness with invasive haemodynamic monitoring data. Stroke volumes were comparable with all three methods. Manual external pacing is an effective holding measure when cardiac output is compromised due to bradycardia or asystole with residual p wave activity before more definitive pacing techniques are instituted.

Comparison of lactate or BE during out-of-hospital cardiac arrest to determine metabolic acidosis

During cardiopulmonary resuscitation, pH and base excess (BE) decrease to a variable degree due to metabolic acidosis. The main cause has been shown to be lactate, which cannot be eliminated sufficiently because of low perfusion during cardiac massage. Both BE and lactate can be measured in the prehospital phase. The aim of the study was to determine if BE and lactate are comparable variables during cardiopulmonary resuscitation (CPR) and if the measurement of lactate level alone would be sufficient to determine the patient's metabolic status and sufficiently reliable to determine the administration of buffer solutions. During the observation period, we registered 31 patients (21 males, ten females) who were resuscitated according to European Resuscitation Council recommendations, who had blood gas analysis and lactate levels measured in blood taken by arterial puncture or arterial line. The first measurement from each patient was taken after primary resuscitation (within 5-20 min). The mean lactate level was 9.85+/-2.98 (range, 4.1-18.7) mmol/l, and the mean BE was -15.0+/-5.98 (range, 5.5 to -24.3). There were statistically significant correlations between the lactate level and BE and pH (linear correlation, r=-0.673, P<0,001 and r=-0,683, P<0,001, respectively), but not with pO2 and pCO2. The receiver-operated curve analysis showed that a cut-off point of 7.0 mmol/l lactate indicates a BE below -10 with a sensitivity of 96% and a specificity of 67%. Lactate measurement is a valuable tool to determine metabolic acidosis during CPR and may be able to replace blood gas analysis in this situation.

The predictive value of ventricular fibrillation electrocardiogram signal frequency and amplitude variables in patients with out-of-hospital cardiac arrest

We evaluated ventricular fibrillation frequency and amplitude variables to predict successful countershock, defined as pulse-generating electrical activity. We also elucidated whether bystander cardiopulmonary resuscitation (CPR) influences these electrocardiogram (ECG) variables. In 89 patients with out-of-hospital cardiac arrest, ECG recordings of 594 countershock attempts were collected and analyzed retrospectively. By using fast Fourier transformation analysis of the ventricular fibrillation ECG signal in the frequency range 0.333-15 Hz (median [range]), median frequency, dominant frequency, spectral edge frequency, and amplitude were as follows: 4.4 (2.4-7.5) Hz, 4.0 (0.7-7.0) Hz, 7.7 (3.7-13.7) Hz, and 0.94 (0.24-1.95) mV, respectively, before successful countershock (n = 59). These values were 3.8 (0.8-7.7) Hz (P = 0.0002), 3.0 (0.3-9.7) Hz (P < 0.0001), 7.3 (2.0-14.0) Hz (P < 0.05), and 0.53 (0.03-3.03) mV (P < 0.0001), respectively, before unsuccessful countershock (n = 535). In patients in whom bystander CPR was performed (n = 51), ventricular fibrillation frequency and amplitude before the first defibrillation attempt were higher than in patients without bystander CPR (n = 38) (median frequency, 4.4 [2.4-7.5] vs 3.7 [1.8-5.3] Hz, P < 0.0001; dominant frequency, 3.8 [0.9-7.7] vs 2.6 [0.8-5.9] Hz, P < 0.0001; spectral edge frequency, 8.4 [4.8-12.9] vs 7.2 [3.9-12.1] Hz, P < 0.05; amplitude, 0.79 [0.06-4.72] vs 0.67 [0.16-2.29] mV, P = 0.0647). Receiver operating characteristic curves demonstrate that successful countershocks will be best discriminated from unsuccessful countershocks by ventricular fibrillation amplitude (3000-ms epoch). At 73% sensitivity, a specificity of 67% was obtained with this variable.

IMPLICATIONS

In patients with out-of-hospital cardiac arrest, successful countershocks will be best discriminated from unsuccessful countershocks by ventricular fibrillation amplitude (3000-ms epoch). At 73% sensitivity, a specificity of 67% was obtained with this variable.