Cardiopulmonary resuscitation: errors made by pre-hospital emergency medical personnel

The role of point-of-care ultrasound (POCUS) imaging in clinical outcomes during cardiac arrest: a systematic review

BACKGROUND

Cardiac arrest in hospital and out-of-hospital settings is associated with high mortality rates. Therefore, a bedside test that can predict resuscitation outcomes of cardiac arrest patients is of great value. Point-of-care ultrasound (POCUS) has the potential to be used as an effective diagnostic and prognostic tool during cardiac arrest, particularly in observing the presence or absence of cardiac activity. However, it is highly susceptible to "self-fulfilling prophecy" and is associated with prolonged cardiopulmonary resuscitation (CPR), which negatively impacts the survival rates of cardiac arrest patients. As a result, the current systematic review was created to assess the role of POCUS in predicting the clinical outcomes associated with out-of-hospital and in-hospital cardiac arrests.

METHODS

The search for scientific articles related to our study was done either through an electronic database search (i.e., PubMed, Medline, ScienceDirect, Embase, and Google Scholar) or manually going through the reference list of the relevant articles. A quality appraisal was also carried out with the Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS-2), and the prognostic test performance (sensitivity and sensitivity) was tabulated.

RESULTS

The search criteria yielded 3984 articles related to our topic, of which only 22 were eligible for inclusion. After reviewing the literature, we noticed a wide variation in the definition of cardiac activity, and the statistical heterogeneity was high; therefore, we could not carry out meta-analyses. The tabulated clinical outcomes based on initial cardiac rhythm and definitions of cardiac activity showed highly inconsistent results.

CONCLUSION

POCUS has the potential to provide valuable information on the management of cardiac arrest patients; however, it should not be used as the sole predictor for the termination of resuscitation efforts.

Utilization of Point-of-Care Ultrasound as an Imaging Modality in the Emergency Department: A Systematic Review and Meta-Analysis

Point-of-care ultrasound (POCUS) is an imaging modality that has become a fundamental part of clinical care provided in the emergency department (ED). The applications of this tool in the ED have ranged from resuscitation, diagnosis, and therapeutic to procedure guidance. This review aims to summarize the evidence on the use of POCUS for diagnosis and procedure guidance. To achieve this, CrossRef, PubMed, Cochrane Library, Web of Science, and Google Scholar databases were extensively searched for studies published between January 2000 and November 2023. Additionally, the risk of bias assessment was performed using the Quality Assessment of Diagnostic Accuracy Studies 2 (for studies on the diagnostic role of POCUS) and Cochrane Risk of Bias tool (for studies on the use of POCUS for procedure guidance). Furthermore, diagnostic accuracy outcomes were pooled using STATA 16 software (StatCorp., College Station, TX, USA), while outcomes related to procedure guidance were pooled using the Review Manager software. The study included 81 articles (74 evaluating the diagnostic application of POCUS and seven evaluating the use of POCUS in guiding clinical procedures). In our findings sensitivities and specificities for various conditions were as follows: appendicitis, 65% and 89%; hydronephrosis, 82% and 74%; small bowel obstruction, 93% and 82%; cholecystitis, 75% and 96%; retinal detachment, 94% and 91%; abscess, 95% and 85%; foreign bodies, 67% and 97%; clavicle fractures, 93% and 94%; distal forearm fractures, 97% and 94%; metacarpal fractures, 94% and 92%; skull fractures, 91% and 97%; and pleural effusion, 91% and 97%. A subgroup analysis of data from 11 studies also showed that the two-point POCUS has a sensitivity and specificity of 89% and 96%, while the three-point POCUS is 87% sensitive and 92% specific in the diagnosis of deep vein thrombosis. In addition, the analyses showed that ultrasound guidance significantly increases the overall success rate of peripheral venous access (p = 0.02) and significantly reduces the number of skin punctures (p = 0.01) compared to conventional methods. In conclusion, POCUS can be used in the ED to diagnose a wide range of clinical conditions accurately. Furthermore, it can be used to guide peripheral venous access and central venous catheter insertion.

Transesophageal Echocardiography in Patients in Cardiac Arrest: The Heart and Beyond

Point of care ultrasound involves different ultrasound modalities and is useful to assist management in emergent clinical situations such as cardiac arrest. The use of point of care ultrasound in cardiac arrest has mainly been described using transthoracic echocardiography as a diagnostic and as a prognostic tool. However, cardiac evaluation using transthoracic echocardiography might be challenging because of patient-related or technical factors. Furthermore, its use during pulse check pauses has been associated with delays in chest compression resumption. Transesophageal echocardiography (TEE) overcomes these limitations by providing reliable and continuous imaging of the heart without interfering with cardiopulmonary resuscitation. In this narrative review we describe the role of TEE during cardiopulmonary resuscitation in 4 different applications: (1) chest compression quality feedback; (2) rhythm characterization; (3) diagnosis of reversible causes; and (4) procedural guidance. Considering its limitations, we propose an algorithm for the integration of TEE in patients with cardiac arrest with a focus on these 4 applications and extend its use to extracardiac applications.

Visual Fixation on the Thorax Predicts Bystander Breathing Detection in Simulated Out-of-Hospital Cardiac Arrest, but Video Debriefing With Eye Tracking Gaze Overlay Does Not Enhance Postallocation Success Rate: A Randomized Controlled Trial

INTRODUCTION

Bystander cardiopulmonary resuscitation in out-of-hospital cardiac arrest is associated with higher survival rates. Even trained health care staff cannot assess breathing well enough to detect cardiac arrest. Recognition of cardiac arrest by lay rescuers might be overlooked in adult basic life support resuscitation guidelines, which explain what to do, but not how to do it. The 2015 Adult Advanced Life Support Resuscitation Guidelines recommend to "look for chest movement." We hypothesize (1) that instructing lay rescuers to look for chest movement allows detecting breathing (or lack thereof); (2) that showing a person their own recorded gaze overlay during a video debriefing intervention enhances breathing detection at postallocation; and (3) that the more time spent looking at a cardiac arrest victim's chest, the greater the probability of detecting breathing (or lack thereof).

METHODS

Monocentric, blinded, prospective, 2-arm parallel randomized controlled trial with balanced randomization (1:1). The design entailed a preallocation simulation, an intervention (video debriefing with or without gaze overlay), and a postallocation simulation. A follow-up simulation took place after 6 months. The main outcome measured was success in detecting breathing. Participants were all prospective students of a bachelor's degree program in nursing.

RESULTS

All participants performed better at postallocation (success rate at preallocation = 59%, postallocation = 79%, χ 2 = 7.22, P < 0.01) regardless of viewing their own gaze overlay during video debriefing. We failed to obtain a sufficient number of participants for the follow-up simulation. Instructing lay rescuers to look for chest movement allows them to detect breathing (or lack thereof). Each second spent looking at the thorax increased the odds of successfully detecting breathing by 38%. Mean thorax gaze duration significantly increased by 5.95 seconds (95% confidence interval = 4.71-7.31) from preallocation (3.46 seconds, SD = 4.16) to postallocation (9.41 seconds, SD = 5.98). Laypersons' median diagnosis time was 15.5 seconds (range = 2-63 seconds), similar to another study (13 seconds, range = 5-40 seconds).

CONCLUSIONS

This is the second study in which the median time to decision exceeded the maximum 10 seconds recommended. International guidelines should consider increasing the time allowed for the "check breathing" step of bystander cardiopulmonary resuscitation procedures.

Point-of-Care Ultrasound Compression of the Carotid Artery for Pulse Determination in Cardiopulmonary Resuscitation

AIM

To identify whether a novel pulse check technique, carotid artery compression using an ultrasound probe, can reduce pulse check times compared to manual palpation (MP).

METHODS

This prospective study was conducted in an emergency department between February and December 2021. A physician applied point-of-care ultrasound-carotid artery compression (POCUS-CAC) and assessed the carotid artery compressibility and pulsatility by probe compression during rhythm check time. Another clinician performed MP of the femoral artery. The primary outcome was the difference in the average time for pulse assessment between POCUS-CAC and MP. The secondary outcomes included the time difference in each pulse check between methods, the proportion of times greater than 5 s and 10 s, and the prediction of return of spontaneous circulation (ROSC) during ongoing chest compression.

RESULTS

25 cardiac arrest patients and 155 pulse checks were analyzed. The median (interquartile range) average time to carotid pulse identification per patient using POCUS-CAC was 1.62 (1.14-2.14) s compared to 3.50 (2.99-4.99) s with MP. In all 155 pulse checks, the POCUS-CAC time to determine ROSC was significantly shortened to 0.44 times the MP time (P < 0.001). The POCUS-CAC approach never exceeded 10 s, and the number of patients who required more than 5 s was significantly lower (5 vs. 37, P < 0.001). Under continuous chest compression, six pulse checks predicted the ROSC.

CONCLUSIONS

We found that emergency physicians could quickly determine pulses by applying simple POCUS compression of the carotid artery in cardiac arrest patients.

Assessing the validity of two-dimensional carotid ultrasound to detect the presence and absence of a pulse

BACKGROUND

Traditional assessment of return of cardiac output in cardiac arrest by manual palpation has poor accuracy. Point of care ultrasound of a major artery has been suggested as an alternative. We conducted a diagnostic accuracy study of two-dimensional carotid ultrasound to detect the presence or absence of a pulse, using cardiopulmonary bypass patients for pulse and pulseless states.

METHODS

A cross-sectional multi-patient, multi-reader repeated measures diagnostic study was conducted. For patients undergoing routine cardiopulmonary bypass, a portable ultrasound was used to record four 10-s videos the common carotid artery, three aimed for a pulse in high (>90 mmHg), medium (70-90 mmHg) and low (<70 mmHg) systolic blood pressure (SBP) ranges, and a pulseless video was recorded on cardiopulmonary bypass. Critical care physicians viewed the videos and were asked to nominate within 10 s if a pulse was present. True pulse-status was determined via the arterial-line waveform.

RESULTS

Twenty-three patients had all four videos collected. Median patient age was 64 (IQR 14), sixteen were male (70%) and median BMI was 27. The median SBP in high-, medium- and low-SBP groups were 120 mmHg, 83 mmHg and 69 mmHg respectively. Forty-six physicians reviewed a subset of 24 videos. Overall sensitivity was 0.91 (95% confidence interval 0.89-0.93) and specificity 0.90 (95% CI 0.86-0.93). Sensitivity was highest in the high-SBP group (0.96, 95% CI 0.93-0.98) and lowest in the low-SBP group (0.83, 95% CI 0.78-0.87).

CONCLUSION

2D ultrasound of the common carotid artery is both sensitive and specific for detection of the presence or absence of a pulse.

Proximity of the Carotid Bifurcation to the Laryngeal Prominence: Results of a Cadaver Study and Recommendations for Safe Pulse Palpation

BACKGROUND/PURPOSE

The carotid bifurcation (CB) is the location of the carotid sinus and the baroreceptors and is also a major site for atherosclerotic plaque formation. Health care providers have therefore been cautioned to avoid the CB during carotid pulse palpation (CPP) to prevent triggering the baroreflex, occluding an artery, or propagating a thrombus. Potential risks of adverse events during CPP may be greater for older adults due to age-related vascular changes and increased risk of baroreceptor hypersensitivity. The exact location of the CB relative to easily identifiable landmarks has, however, not been well-studied. The purpose of this descriptive study was to identify the location of the CB relative to key landmarks in a cadaver sample and to make recommendations allowing clinicians to avoid the CB during CPP.

METHODS

The CB and other regional landmarks in 17 male and 20 female cadavers were exposed by dissection and pins were placed at all landmarks. Digital calipers were then used to measure the distance between the CB and all landmarks.

RESULTS AND DISCUSSION

The mean vertical distance from the laryngeal prominence (LP) to the CB was 25.14 mm for females and 36.13 mm for males. No CBs were located below the LP. Ninety-four percent of female CBs and 100% of male CBs were located above the LP, and 74% of female subjects and 87% of male subjects had CBs greater than 20.00 mm superior to the LP. No clinically relevant relationships were found between the CB and any of the other measured landmarks.

CONCLUSIONS

Based on this cadaver sample, CPP below the level of the LP in a supine individual would be unlikely to compress the CB and thus unlikely to trigger the baroreflex or occlude the region of greatest atherosclerotic buildup. If a pulse is not palpable below the LP, moving vertically up to 1 cm above the LP in a supine individual would be likely to compress the CB in only a small number of cases.

The POCUS pulse check: A randomized controlled crossover study comparing pulse detection by palpation versus by point-of-care ultrasound

BACKGROUND

Manual pulse checks (MP) are an unreliable skill even in the hands of healthcare providers (HCPs). In the context of cardiac arrest, this may translate into inappropriate chest compressions when a pulse is present, or conversely omitting chest compressions when one is absent. To date, no study has assessed the use of B-mode ultrasound (US) for the detection of a carotid pulse. The primary objective of this study was to assess the time required to detect a carotid pulse in live subjects using US compared to the traditional palpation method.

METHODS

We conducted a prospective randomized controlled crossover non-inferiority trial. HCPs attended a 15 minute focused US workshop on identification of the carotid pulse. Both pulse check methods were timed for each participant on two different subjects in random order. The primary outcome was time to carotid pulse detection in seconds (s). Secondary outcomes included confidence levels of pulse detection measured on a 100 mm visual analog scale (VAS) and rates of prolonged pulse checks (> 5 s or >10 s). The study was powered to determine whether US pulse checks were not slower than MP by greater than two seconds. The results are presented as the difference in means with a 90% two-sided confidence interval (CI).

RESULTS

111 participants completed the study. Mean pulse detection times were 4.22 s (SD 3.26) by US compared to 4.71 s (SD 6.45) by MP with a mean difference in times of -0.49 s (90% CI: -1.77 to 0.39). There were no significant differences between US and MP in the rates of prolonged pulse checks of greater than 5 s (23% vs 19%, p = 0.45) or 10 s (9% vs 8%, p = 0.81). First attempt at detection of pulse checks was more successful in the US group (99.1% vs 85.6%, p = 0.0001). Prior to training, participants reported higher confidence using MP compared to US; 68 (IQR 48-83) vs 15 (IQR 8-42) mm (p < 0.001). Following the study, participants reported higher confidence levels using US than MP; 91 (IQR 82-97) vs 83 (IQR 72-94) mm (p < 0.001).

CONCLUSIONS

Carotid pulse detection in live subjects was not slower using US as compared to palpation, and demonstrated higher first attempt success rate and less variability in measurement times. A brief teaching session was sufficient to improve confidence of carotid pulse identification even in those with no previous US training. The preliminary results from this study provide the groundwork for larger studies to evaluate this pulse check method for patients in cardiac arrest.

Wilderness First Responder: Are Skills Soon Forgotten?

Wilderness first responders are trained to provide competent medical care in wilderness settings or until evacuation for more advanced treatment can be obtained. In light of the isolated environments in which they are called upon to respond to illnesses and injuries, their ability to effectively apply their training is crucial. Despite the responsibility assigned to them, there is an absence of research assessing the skill and knowledge retention of wilderness first responders, creating a gap in understanding whether a deficit in their ability to perform exists between certifications. Without such research, it is important to review knowledge and skill retention in related responder groups. The literature over the past 4 decades documents the loss over time of skills and knowledge across an array of trained responders, both professional and laypeople. Although the findings reviewed suggest that WFRs will exhibit a similar pattern of increasing skill loss beginning shortly after certification and a slower, but concurrent, decrease in knowledge, research is needed to document or refute this assumption.

Echocardiography in cardiac arrest: An emergency medicine review

INTRODUCTION

Cardiac arrest management primarily focuses on optimal chest compressions and early defibrillation for shockable cardiac rhythms. Non-shockable rhythms such as pulseless electrical activity (PEA) and asystole present challenges in management. Point-of-care ultrasound (POCUS) in cardiac arrest is promising.

OBJECTIVES

This review provides a focused assessment of POCUS in cardiac arrest, with an overview of transthoracic (TTE) and transesophageal echocardiogram (TEE), uses in arrest, and literature support.

DISCUSSION

Cardiac arrest can be distinguished between shockable and non-shockable rhythms, with management varying based on the rhythm. POCUS provides a diagnostic and prognostic tool in the emergency department (ED), which may improve accuracy in clinical decision-making. Several protocols incorporate POCUS based on different cardiac views. TTE includes parasternal long axis, parasternal short axis, apical 4-chamber, and subxiphoid views, which may be used in cardiac arrest for diagnosis of underlying cause and potential prognostication. TEE is conducted by inserting the probe into the esophagus of intubated patients, with several studies evaluating its use in cardiac arrest. It is associated with few adverse effects, while allowing continued compressions (and evaluation of those compressions) and not interrupting resuscitation efforts.

CONCLUSIONS

POCUS is a valuable diagnostic and prognostic tool in cardiac arrest, with recent literature supporting its diagnostic ability. TTE can guide resuscitation efforts dependent on the rhythm, though TTE should not interrupt other resuscitation measures. TEE can be useful during arrest, but further studies based in the ED are needed.

Safety Events in High Risk Prehospital Neonatal Calls

OBJECTIVE

The objective of this study was to quantify and characterize patient safety events during high-risk neonatal transports in the prehospital setting.

METHOD

We conducted a retrospective chart review of all "lights and sirens" ambulance transports of neonates ≤30 days old over a four-year period in a metropolitan area. Each case was independently reviewed for potential patient safety events that may have occurred in clinical assessment and decision making, resuscitation, airway management, fluid or medication administration, procedures performed, and/or equipment used.

RESULTS

Twenty-six patients ≤30 days old were transported by ambulance using lights and sirens during the four-year study period. Overall, safety events occurred in 19 patients and severe safety events (potentially causing permanent injury or harm, including death) occurred in ten. The incidence of safety events related to medication administrations was 90% (70% severe), resuscitation 64.7% (47.1% severe), procedures 64.7% (35.3% severe), fluid administration 50% (25% severe), clinical assessment and decision making 50% (30.8% severe), airway management 47.6% (28.6% severe), equipment use 25.5% (10.0% severe), and systems processes 19.2% (7.7% severe).

CONCLUSIONS

High-risk neonatal calls are infrequent and prone to a high incidence of serious patient safety events.

The importance of victim chest exposure during cardiopulmonary resuscitation: a simulation study

BACKGROUND

During cardiopulmonary resuscitation (CPR), inaccurate positioning of the rescuer's hand might damage internal organs due to compression around the xiphoid process.

OBJECTIVE

This study aimed to determine whether exposing the victim's chest during CPR would help adequate positioning of a rescuer's hand on the chest.

METHODS

This simulation study included 187 participants. We gave them four photographs each of exposed chests and unexposed chests. Participants were then asked to mark a cross at the center of the chest (CoC) and at the inter-nipple line (INL), and we measured the width of participants' palms to estimate the range of hand contact with the victim's chest. Finally, we compared the position and distribution of the CoC and INL markings and analyzed whether the hand contact range on the victim's chest involved the xiphoid process.

RESULTS

The participants' CoC markings were similar regardless of whether the pictures showed an exposed or unexposed chest (p = 0.638). However, the level of INL marking was significantly lower in pictures of an exposed chest (p < 0.001). When exposing the chest, the distribution of markings was narrower for both CoC (p = 0.001) and INL (p < 0.001). The proportion of CoC markings involving the xiphoid process were lower when the chest was exposed (10.7%) than when was clothed (12.3%) (p < 0.001). Similarly, INL markings involving the xiphoid process followed the same trend in exposed vs. unexposed chest images (0% vs. 1.6%, respectively).

CONCLUSIONS

Exposing the chest during CPR can improve the rescuer's ability to recognize the CoC and INL, leading to more intense chest compression and reducing the risk of inaccurate compression.

Mapping the use of simulation in prehospital care - a literature review

Background

High energy trauma is rare and, as a result, training of prehospital care providers often takes place during the real situation, with the patient as the object for the learning process. Such training could instead be carried out in the context of simulation, out of danger for both patients and personnel. The aim of this study was to provide an overview of the development and foci of research on simulation in prehospital care practice.

Methods

An integrative literature review were used. Articles based on quantitative as well as qualitative research methods were included, resulting in a comprehensive overview of existing published research. For published articles to be included in the review, the focus of the article had to be prehospital care providers, in prehospital settings. Furthermore, included articles must target interventions that were carried out in a simulation context.

Results

The volume of published research is distributed between 1984- 2012 and across the regions North America, Europe, Oceania, Asia and Middle East. The simulation methods used were manikins, films, images or paper, live actors, animals and virtual reality. The staff categories focused upon were paramedics, emergency medical technicians (EMTs), medical doctors (MDs), nurse and fire fighters. The main topics of published research on simulation with prehospital care providers included: Intubation, Trauma care, Cardiac Pulmonary Resuscitation (CPR), Ventilation and Triage.

Conclusion

Simulation were described as a positive training and education method for prehospital medical staff. It provides opportunities to train assessment, treatment and implementation of procedures and devices under realistic conditions. It is crucial that the staff are familiar with and trained on the identified topics, i.e., intubation, trauma care, CPR, ventilation and triage, which all, to a very large degree, constitute prehospital care. Simulation plays an integral role in this. The current state of prehospital care, which this review reveals, includes inadequate skills of prehospital staff regarding ventilation and CPR, on both children and adults, the lack of skills in paediatric resuscitation and the lack of knowledge in assessing and managing burns victims. These circumstances suggest critical areas for further training and research, at both local and global levels.

Basic life support and automated external defibrillator skills among ambulance personnel: a manikin study performed in a rural low-volume ambulance setting

BACKGROUND

Ambulance personnel play an essential role in the 'Chain of Survival'. The prognosis after out-of-hospital cardiac arrest was dismal on a rural Danish island and in this study we assessed the cardiopulmonary resuscitation performance of ambulance personnel on that island.

METHODS

The Basic Life Support (BLS) and Automated External Defibrillator (AED) skills of the ambulance personnel were tested in a simulated cardiac arrest. Points were given according to a scoring sheet. One sample t test was used to analyze the deviation from optimal care according to the 2005 guidelines. After each assessment, individual feedback was given.

RESULTS

On 3 consecutive days, we assessed the individual EMS teams responding to OHCA on the island. Overall, 70% of the maximal points were achieved. The hands-off ratio was 40%. Correct compression/ventilation ratio (30:2) was used by 80%. A mean compression depth of 40-50 mm was achieved by 55% and the mean compression depth was 42 mm (SD 7 mm). The mean compression rate was 123 per min (SD 15/min). The mean tidal volume was 746 ml (SD 221 ml). Only the mean tidal volume deviated significantly from the recommended (p = 0.01). During the rhythm analysis, 65% did not perform any visual or verbal safety check.

CONCLUSION

The EMS providers achieved 70% of the maximal points. Tidal volumes were larger than recommended when mask ventilation was applied. Chest compression depth was optimally performed by 55% of the staff. Defibrillation safety checks were not performed in 65% of EMS providers.

Adequacy of chest compressions performed by medical housestaff

BACKGROUND

Chest compressions (CCs) are a critical part of cardiopulmonary resuscitation. We studied the presence and duration of adequate CCs performed by medical housestaff, and correlated our findings with gender and body mass index.

METHODS

Fifty-eight first-postgraduate-year medical housestaff performed CCs on a computerized patient simulator equipped with a calibrated CC measurement device. Following initial testing, subjects were trained to perform adequate CCs. Subjects were retested 2 weeks later. Presence and duration of adequate CCs were measured during a 120-second endurance test.

RESULTS

Before training, 14/28 (50%) of the male housestaff performed adequate CCs and 0/30 (0%) of the female housestaff performed adequate CCs. After training, 25/28 (89%) of the male housestaff and 16/30 (53%) of the female housestaff performed adequate CCs. Body mass index and height were not related to adequacy of CCs. After training, 7/28 (25%) of the male subjects and 1/30 (3%) of the female subjects were able to maintain adequate CCs for 120 seconds.

CONCLUSIONS

Training housestaff on a patient simulator is an effective means of improving the adequacy of CCs. Despite training, a significant number of women were unable to perform adequate CCs compared with men; body mass index and height were not determining factors. Very few housestaff were able to sustain 120 seconds of adequate CCs, despite training.

Focused examination of cerebral blood flow in peri-resuscitation: a new advanced life support compliant concept—an extension of the focused echocardiography evaluation in life support examination

Aim

To introduce a new concept of the extension of focused echocardiography evaluation in life support (FEEL) with advanced life support (ALS)-compliant duplex sonography of the extracranial internal carotid artery (ICA) blood flow velocity for monitoring of cerebral blood circulation during peri-resuscitation.

Concept and results

With respect to pulseless electrical activity states, the question of adequate cerebral blood flow (CBF) cannot be answered by echocardiography alone. Pulse checks are unreliable. To build up a concept for assessing CBF, we analyzed duplex sonography workflow in three adults on the intensive care unit (postoperative, cardiogenic shock, cardiac standstill), and in simulated procedures. We decided to use duplex flow velocity of the ICA, for it is an accepted measurement for estimating CBF and it seems to be easy to obtain a window and interpretation during peri-resuscitation. The presence of an arterial blood flow pattern and an end-diastolic flow velocity of more than 20 cm/s, arbitrarily set, is considered to indicate sufficient CBF. The method of ICA flow velocity analysis during peri-resuscitation was tentatively added to the FEEL concept and is described with algorithm, workflow and three cases. This method may give an assist to answer the question, if CBF is sufficient, when myocardial wall motion is detectable in peri-resuscitation care.

Conclusion

This new concept of an ALS-conformed analysis of ICA blood flow velocity by duplex sonography may provide a simple, fast applicable and inexpensive method to qualitatively assess CBF in the peri-resuscitation setting.

Safety of the inter-nipple line hand position landmark for chest compression

BACKGROUND

No previous study has investigated the safety of hand position during chest compression determined by the inter-nipple line, in which the heel of one hand is positioned on the centre of the chest between the nipples, from the standpoint of prevention of organ injury.

METHODS

We measured the distance from the xiphisternal junction to the inter-nipple line (dN) in 1000 surgical patients and the heel length (H) of hands in 100 healthy volunteers, then used the formula H/2-dN to determine the amount of deviation when the heel of the rescuer's hand extended to the xiphoid process (D). Next, 100 surgical patients were randomly assigned to 18 anaesthesiologists, who placed the heels of their hands on the sternum for validation.

RESULTS

The D value was positive in 551 patients, indicating that the heel may extend to the xiphoid process during chest compression in those individuals. Multivariate logistic-regression analyses showed that deviations beyond the xiphoid process to the epigastric region were more likely to occur in female (OR 3.52), elderly (OR 2.00), and short-statured (OR 2.09) patients, and with male rescuers (OR 2.81). During actual positioning, deviation occurred in 51 patients and extended to the epigastric region in 5 females.

CONCLUSIONS

Simulation of hand position determined by the inter-nipple line resulted in placement of the rescuer's hands over the xiphoid process in nearly half of the patients. Hand deviation to the epigastric region may occur when the patient is a short-statured or elderly female, and when the rescuer is male.

Keeping Cool: A Case for Hypothermia After Cardiopulmonary Resuscitation

Cessation of circulation during cardiac arrest causes critical end-organ ischemia. Although the neurological consequences of cardiopulmonary arrest can be catastrophic, an aggressive “push fast and push hard” resuscitation technique maintains blood flow until the return of spontaneous circulation. However, reperfusion to the cerebrum leads to cellular chaos and further neurological injury. Use of moderate hypothermia after cardiac arrest mediates these cellular and chemical processes, reducing the impact of the arrest and reperfusion phenomena. A 43-year-old man had 2 asystolic arrests with 20 minutes of cardiopulmonary resuscitation as a result of massive, multiple pulmonary emboli. After the cardiac arrest, the patient was comatose and posturing. The 2005 American Heart Association guidelines for cardiopulmonary resuscitation were used along with moderate hypothermia in an attempt to minimize the neurological consequences of the cardiopulmonary arrest and to optimize the patient’s outcome.

Two rescuer resuscitation—Mission impossible?

OBJECTIVE

Advanced life support (ALS) in a cardiac arrest is usually performed by a team consisting of three people. The medical team of a Helicopter Emergency Medical Service (HEMS) often consists of two rescuers only. Due to that reason an algorithm was developed to provide ALS with two people. During the initial phase the rescuer in the over-the-head position provides one man CPR while the second rescuer prepares all advanced measures. When all preparations are complete both rescuers are able to provide ALS.

MATERIAL AND METHODS

A computer controlled manikin (Ambu Mega Code Simulator System MCS with online documentation was used to test the entire medical staff during 10 min of persistent VF.

RESULTS

The 20 teams were tested. Following data were recorded: no-flow-time 96.4+/-11s (16.1+/-1.8%), chest compression frequency 120.1+/-5.1 min (-1), ventilation frequency=9 min (-1), number of chest compressions per session 1013.7+/-45.9, depth of chest compressions 46.6+/-2.5mm, total number of chest compressions=20,274, total number of ventilations=1893. For ALS measures the following data were recorded: tracheal intubation (TI) was finished after 60.7+/-9.8s, duration of TI : maneuver = 15.7+/-4.4s, end of initial phase=188.9+/-26.3s, i.v. administration of adrenaline after 387.7+/-33.6s, i.v. administration of amiodarone after 507.9+/-36.9s and four shocks after: 138.0+/-15.9, 266.8+/-16.1, 398.0+/-20.1 and 526.8+/-23.6s.

CONCLUSION

We proved the feasibility of the algorithm in a manikin setting. Further observations have to prove the algorithm in real CPR situations.

Focused echocardiographic evaluation in resuscitation management: Concept of an advanced life support–conformed algorithm

Emergency ultrasound is suggested to be an important tool in critical care medicine. Time-dependent scenarios occur during preresuscitation care, during cardiopulmonary resuscitation, and in postresuscitation care. Suspected myocardial insufficiency due to acute global, left, or right heart failure, pericardial tamponade, and hypovolemia should be identified. These diagnoses cannot be made with standard physical examination or the electrocardiogram. Furthermore, the differential diagnosis of pulseless electrical activity is best elucidated with echocardiography. Therefore, we developed an algorithm of focused echocardiographic evaluation in resuscitation management, a structured process of an advanced life support-conformed transthoracic echocardiography protocol to be applied to point-of-care diagnosis. The new 2005 American Heart Association/European Resuscitation Council/International Liaison Committee on Resuscitation guidelines recommended high-quality cardiopulmonary resuscitation with minimal interruptions to reduce the no-flow intervals. However, they also recommended identification and treatment of reversible causes or complicating factors. Therefore, clinicians must be trained to use echocardiography within the brief interruptions of advanced life support, taking into account practical and theoretical considerations. Focused echocardiographic evaluation in resuscitation management was evaluated by emergency physicians with respect to incorporation into the cardiopulmonary resuscitation process, performance, and physicians' ability to recognize characteristic pathology. The aim of the focused echocardiographic evaluation in resuscitation management examination is to improve the outcomes of cardiopulmonary resuscitation.

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.

Relationship between knowledge of cardiopulmonary resuscitation guidelines and performance

OBJECTIVE

Despite widespread training with CPR guidelines, CPR is often poorly performed. We explore relationships between knowledge of CPR guidelines and performance (compression rate, compression depth, compression to ventilation ratio, and ventilation volume).

METHODS

Sixty professional EMTs were sampled at 26 randomly ordered EMS response stations from an urban system of 31 stations. A recording manikin and video model were used to assess performance in a standardized scenario, and a survey was used to assess guideline knowledge. Survey and performance outcomes were categorized prospectively as correct or incorrect based on the International CPR Guidelines from 2000. Relationships were modeled with logistic regression. Covariates included years of work experience, frequency of CPR performance, and ALS versus BLS EMT level.

RESULTS

Compression rate was between 80 and 120 min(-1) in 56% (33/59) of trials. Compression depth was 1.5-2 in. in 39% (23/59), compression to ventilation ratio approximated to 15:2 in 42% (25/59), and ventilation volume was 800-1,200 cm(3) in 13% (8/60). Accurate knowledge of the CPR guidelines was associated with better performance of chest compression rate and compression to ventilation ratio. Adjusted OR (95% CI) were 4.6 (1.2-18.1) for compression rate, 1.7 (0.4-6.5) for compression depth, 4.5 (1.1-18.5) for compression to ventilation ratio, and 9.0 (0.2-351) for ventilation volume.

CONCLUSIONS

Although accurate knowledge of guidelines is associated with increased odds of correct performance of some aspects of CPR, overall performance remains poor.

The effect of a voice assist manikin (VAM) system on CPR quality among prehospital providers

Numerous studies have documented poor cardiopulmonary resuscitation (CPR) performance among prehospital providers during both simulated and actual resuscitations. Previous studies have shown that a real-time, voice assist manikin (VAM) system may improve CPR performance.

OBJECTIVE

To determine whether VAM prompting would improve CPR performance by prehospital providers during simulated resuscitation.

METHODS

In this prospective, randomized, crossover design, 114 prehospital providers performed two 3-minute sessions of one-rescuer CPR on a VAM-resuscitation manikin: one round with the VAM feature turned on and one with the feature turned off. The primary outcomes were measured at 15-second intervals and included the fraction of correct compressions, the mean compression depth, the fraction of correct ventilations, and the mean ventilation tidal volume. Generalized estimating equations were used to analyze the repeated measures.

RESULTS

The VAM prompting was not directly associated with correct compressions during one-rescuer CPR in a cohort of subjects naïve to the system. However, the general decay in correct compressions seen over 3 minutes was attenuated with VAM prompting. Neither the compression depth nor the decay in compression depth over time was affected by VAM prompting. In contrast, VAM prompting did affect the fraction of correct ventilations and attenuated the time-dependent decline in correct ventilations in tidal volume.

CONCLUSIONS

Use of VAM did not directly improve compression or ventilation rate or quality in this cohort of prehospital providers. However, use of VAM did prevent decay of compression and ventilation performance over time.

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.

["Topless" cardiopulmonary resuscitation. Fashion or science?]

A decade after the onset of a discussion whether ventilation could be omitted from bystander basic life support (BLS) algorithms, the state of the evidence is reevaluated. Initial animal studies and a prospective randomized patient trial had suggested that omission of ventilation during the first minutes of lay cardiopulmonary resuscitation (CPR) did not impair patient outcomes. More recent studies demonstrate, however, that this may hold true only in very specific scenarios, and that the chest compression-only technique was never superior to standard BLS. Instead of calling basics of BLS training and practice into question, more and better training of lay persons and professionals appears mandatory, and targeted use of dispatcher-guided telephone CPR should be evaluated and, if it improves outcome, it should be encouraged. Future studies should focus much less on the omission but on the optimization of ventilation under the specific conditions of CPR.

Learning effect of a novel interactive basic life support CD: the JUST system

INTRODUCTION

Electronic interactive learning environments can enhance the learning experience and may prove beneficial in basic life support (BLS) training. As part of the European Union funded project "JUST-in-time health emergency interventions-training of non-professionals by virtual reality and advanced IT tools", an innovative interactive CD-ROM on BLS and other emergency medicine topics was developed. We hypothesised that individuals without previous BLS training could learn CPR techniques from this CD.

METHODS

Sixty-two students were randomised into a group studying the JUST CD in a computer class room for up to 60 min, and a control group who did not receive any training (serving as a reference). CD users also completed a satisfaction questionnaire immediately after studying the CD. The BLS skills of both groups were assessed in a mock BLS scenario on a training manikin. BLS performance was video recorded and analysed.

RESULTS

After studying the CD for a mean period of 42 min, users of the CD had better assessment skills and were more likely to show a positive helping attitude, but chest compression and breathing techniques were ineffective. Most users rated the CD as very good and a positive learning tool.

CONCLUSION

Individuals without prior BLS training showed improved behaviour and assessment skills after exposure to the CD, but motor skill acquisition requires alternative learning strategies.

The effect of seeing the rhythm display on performance of cardiopulmonary resuscitation

Semiautomated external defibrillators are widely used by prehospital emergency personnel. Some of the devices have a rhythm display and some show only text commands on the screen. To evaluate the effects on cardiopulmonary resuscitation (CPR) performance of seeing the rhythm during resuscitation, 60 fire-fighter students were randomly divided in two groups and trained to use either a defibrillator with a rhythm display or one without a display. The students in both groups formed teams of two rescuers, and their performance of CPR on a manikin was tested using a predefined rhythm sequence in a simulated cardiac arrest situation. The teams using a defibrillator with a rhythm display more often interrupted CPR for pulse checks than those who did not see the rhythm (P=0.003). The duration of CPR between rhythm analyses was shorter in the group who saw the rhythm on the screen (P=0.002). Our data suggest that seeing an organised rhythm on a monitor during CPR interferes with adherence to CPR algorithms which may have a negative influence on the performance of CPR.

Prehospital advanced life support provided by specially trained physicians: is there a benefit in terms of life years gained?

BACKGROUND

The benefit of prehospital advanced life support (ALS) is disputed, as is the prehospital use of specially trained, hospital-based physicians. The purpose of the study was to assess the health benefit from an anesthesiologist-manned prehospital emergency medical service (EMS), and to separate the benefit of the anesthesiologist from that of rapid transport.

METHODS

The anesthesiologist-manned helicopter and rapid response car service at Rogaland Central Hospital assisted 1106 patients at the scene during the 18-month study period. Two expert panels assessed patients with a potential health benefit for life years gained (LYG) using a modified Delphi technique. The probability of survival as a result of the studied EMS was multiplied by the life expectancy of each patient. The benefit was attributed either to the anesthesiologist, the rapid transport or a combination of both.

RESULTS

The expert panels estimated a benefit of 504 LYG in 74 patients (7% of the total study population), with a median age of 54 years (range 0-88). The cause of the emergency was cardiac diseases (including cardiac arrest) in 61% of the 74 patients, trauma in 19%, and cardio-respiratory failure as a result of other conditions in 20%. The LYG were equally divided between air and ground missions, and the majority (88%) were attributed solely to ALS by the anesthesiologist.

CONCLUSION

The expert panels found LYG in every 14th patient assisted by this anesthesiologist-manned prehospital EMS. There was no difference in LYG between the helicopter and the rapid response car missions. The role of the anesthesiologist was crucial for health benefits.

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.

Compression depth estimation for CPR quality assessment using DSP on accelerometer signals

Chest compression is a vital part of cardiopulmonary resuscitation (CPR). This paper demonstrates how the compression depth can be estimated using the principles of inertia navigation. The proposed method uses accelerometer sensors, one placed on the patient's chest, the other beside the patient. The acceleration-to-position conversion is performed using discrete-time digital signal processing (DSP). Instability problems due to integration are combated using a set of boundary conditions. The proposed algorithm is tested on a mannequin in harsh environments, where the patient is exposed to external forces as in a boat or car, as well as improper sensor/patient alignment. The overall performance is an estimation depth error of 4.3 mm in these environments, which is reduced to 1.6 mm in a regular, flat-floor controlled environment.

Part 9: pediatric basic life support. European Resuscitation Council

The epidemiology and outcome of pediatric cardiopulmonary arrest and the priorities, techniques, and sequence of pediatric resuscitation assessments and intervention differ from those of adults. Current guidelines have been updated after extensive multinational evidence-based review and discussion over several years. Areas of controversy in current guidelines and recommendations made by consensus are detailed. A large degree of uniformity exists in the current guidelines advocated by the AHA, Council on Latin American Resuscitation, Heart and Stroke Foundation of Canada, European Resuscitation Council, Australian Resuscitation Council, and Resuscitation Council of Southern Africa. Differences are currently based on local and regional preferences, training networks, and customs rather than scientific controversy. Unresolved issues with potential for future universal application are highlighted.