Single rescuer cardiopulmonary resuscitation: Can anyone perform to the guidelines 2000 recommendations?

BACKGROUND: The Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care recommend that for adult cardiac arrest the single rescuer performs "two quick breaths followed by 15 chest compressions." This cycle is continued until additional help arrives. Previous studies have shown that lay persons and medical students take 16 +/- 1 and 14 +/- 1 s, respectively, to perform these "two quick breaths." The purpose of this study was to determine the time required for trained professional paramedic firefighters to deliver these two breaths and the effects that any increase in the time it takes to perform rescue breathing would have on the number of chest compressions delivered during single rescuer BLS CPR. We hypothesized that trained professional rescuers would also take substantially longer then the Guidelines recommendation for delivering the two rescue breaths before every 15 compressions during simulated single rescuer BLS CPR. METHODS: Twenty-four paramedic firefighters currently certified to perform BLS CPR were evaluated for their ability to deliver the two recommended breaths within 4 s according to the AHA 2000 CPR Guidelines. Alternatively, a simplified technique of continuous chest compression BLS CPR (CCC) was also taught and compared with standard BLS CPR (STD). Without revealing the purpose of the study the paramedics were asked to perform single rescuer BLS CPR on a recording Resusci Anne while being videotaped. RESULTS: The mean length of time needed to provide the "two quick breaths" during STD-CPR was 10 +/- 1 s. The mean number of chest compressions/min delivered with AHA BLS CPR was only 44 +/- 2. Continuous chest compression CPR resulted in 88 +/- 5 compressions delivered per minute (STD versus CCC; p < 0.0001). CONCLUSIONS: Trained professional emergency rescue workers perform rescue breathing somewhat faster than lay rescuers or medical students, but still require two and one half times longer than recommended. The time required to perform these breaths significantly decreases the number of chest compressions delivered per minute. This may affect outcome as experimental studies have shown that more than 80 compressions delivered per minute are necessary for survival from prolonged cardiac arrest.     

Effect of rescuer fatigue on performance of continuous external chest compressions over 3 min

Guidelines for the performance of cardiopulmonary resuscitation (CPR) have been revised recently and now advocate that chest compressions are performed without interruption for 3 min in patients during asystole and pulseless electrical activity. The aim of the present study was to determine if rescuer fatigue occurs during 3 min of chest compressions and if so, the effects on the rate and quality of compressions. Forty subjects competent in basic life support (BLS) were studied. They performed continuous chest compressions on a Laerdal Skillmeter Resusci-Anne manikin for two consecutive periods of 3 min separated by 30 s. The total number of compressions attempted was well maintained at approximately 100 min(-1) throughout the period of study. However, the number of satisfactory chest compressions performed decreased progressively during resuscitation (P < 0.001) as follows: first min, 82 min(-1); second, 68 min(-1); third, 52 min(-1); fourth, 70 min(-1); fifth, 44 min(-1); sixth, 27 min(-1). We observed significant correlations between the number of satisfactory compressions performed and both height and weight of the rescuer. Female subjects achieved significantly fewer satisfactory compressions compared with males (P = 0.03). Seven subjects (five female, two male) were unable to complete the second 3-min period because of exhaustion. We conclude that rescuer fatigue adversely affects the quality of chest compressions when performed without interruption over a 3-min period and that this effect may be greater in females due to their smaller stature. Consideration should be given to rotating the rescuer performing chest compressions after 1 min intervals.     

Increased chest compression to ventilation ratio improves delivery of CPR

OBJECTIVE: Chest compressions are interrupted during cardiopulmonary resuscitation (CPR) due to human error, for ventilation, for rhythm analysis and for rescue shocks. Earlier data suggest that the recommended 15:2 compression to ventilation (C:V) ratio results in frequent interruptions of compressions during CPR. We evaluated a protocol change from the recommended C:V ratio of 15:2-30:2 during CPR in our municipal emergency medical system. METHODS: Municipal firefighters (N=875) from a single city received didactic and practical training emphasizing the importance of continuous chest compressions and recommending a 30:2 C:V ratio. Both before and after the training, digital ECG and voice records from all first-responder cases of out-of-hospital cardiac arrest were examined off-line to quantify chest compressions. The number of chest compressions delivered and the number and duration of pauses in chest compressions were compared by t-test for the first three 1min intervals when CPR was recommended. RESULTS: More compressions were delivered during minutes 1, 2, and 3 during CPR with the 30:2 C:V ratio (78+/-29, 80+/-30, 74+/-26) than with the 15:2C:V ratio (53+/-24, 57+/-24, 51+/-26) (p<0.001). Fewer pauses for ventilation occurred during each minute with the 30:2 C:V ratio (1.7+/-1.2, 2.2+/-1.2, 1.8+/-1.0) than with the 15:2C:V ratio (3.4+/-2.6, 4.7+/-7.2, 4.0+/-2.9) (p< or =0.01). Degradation of the final ECG to asystole occurred less frequently after the protocol change (asystole pre 67.1%, post 56.8%, p<0.05). The incidence of return of spontaneous circulation was not altered following the protocol change. CONCLUSIONS: Retraining first responders to use a C:V ratio of 30:2 instead of the traditional 15:2 during out-of-hospital cardiac arrest increased the number of compressions delivered per minute and decreased the number of pauses for ventilation. These data are new as they produced persistent and quantifiable changes in practitioner behavior during actual resuscitations.     

A 10-s rest improves chest compression quality during hands-only cardiopulmonary resuscitation: A prospective,randomized crossover study using a manikin model

Objectives

This study was designed to assess changes in cardiopulmonary resuscitation (CPR) quality and rescuer fatigue when rescuers are provided with a break during continuous chest compression CPR (CCC-CPR).

Methods

The present prospective, randomized crossover study involved 63 emergency medical technician trainees. The subjects performed three different CCC-CPR methods on a manikin model. The first method was general CCC-CPR without a break (CCC), the second included a 10-s break after 200 chest compressions (10/200), and the third included a 10-s break after 100 chest compressions (10/100). All methods were performed for 10 min. We counted the total number of compressions and those with appropriate depth every 1 min during the 10 min and measured mean compression depth from the start of chest compressions to 10 min.

Results

The 10/100 method showed the deepest compression depth, followed by the 10/200 and CCC methods. The mean compression depth showed a significant difference after 5 min had elapsed. The percentage of adequate compressions per min was calculated as the proportion of compressions with appropriate depth among total chest compressions. The percentage of adequate compressions declined over time for all methods. The 10/100 method showed the highest percentage of adequate compressions, followed by the 10/200 and CCC methods.

Conclusion

When rescuers were provided a rest at a particular time during CCC-CPR, chest compression quality increased compared with CCC without rest. Therefore, we propose that a rescuer should be provided a rest during CCC-CPR, and specifically, we recommend a 10-s rest after 100 chest compressions.     

Role of dominant versus non-dominant hand position during uninterrupted chest compression CPR by novice rescuers: a randomized double-blind crossover study

BACKGROUND: Previous research has suggested improved quality of chest compressions when the dominant hand was in contact with the sternum. However, the study was in health care professionals and during conventional chest compression-ventilation CPR. The aim of this study was to test the hypothesis, in null form, that the quality of external chest compressions (ECC) in novice rescuers during 5min of uninterrupted chest compression CPR (UCC-CPR) is independent of the hand in contact with the sternum. Confirmation of the hypothesis would allow the use of either hand by the novice rescuers during UCC-CPR. METHODS: Fifty-nine first year public heath students participated in this randomised double-blind crossover study. After completion of a standard adult BLS course, they performed single rescuer adult UCC-CPR for 5 min on a recording Resusci Anne. One week later they changed the hand of contact with the sternum while performing ECC. The quality of ECC was recorded by the skill meter for the dominant and non-dominant hand during 5 min ECC. RESULTS: The total number of correct chest compressions in the dominant hand group (DH), mean 183+/-152, was not statistically different from the non-dominant hand group (NH), mean 152+/-135 (P=0.09). The number of ECC with inadequate depth in the DH group, mean 197+/-174 and NH group, mean 196+/-173 were comparable (P=0.1). The incidence of ECC exceeding the recommended depth in the DH group, mean 51+/-110 and NH group, mean 32+/-75 were comparable (P=0.1). CONCLUSIONS: Although there is a trend to increased incidence of correct chest compressions with positioning the dominant hand in contact with the sternum, it does not reach statistical significance during UCC-CPR by the novice rescuers for 5 min.     

Single-rescuer cardiopulmonary resuscitation: 'two quick breaths'--an oxymoron

The Guidelines 2000 for CPR and ECC recommend for single lay-rescuers performing basic life support, "two quick breaths followed by 15 chest compressions", repeated until professional help arrives. It is uncertain that this can actually be accomplished by the majority of lay rescuers. We evaluated 53 first-year medical students after completing BLS CPR training to determine if they could deliver the goal of 80 compressions per minute when following this AHA BLS recommendation. Alternatively, a simplified technique of uninterrupted chest compression (UCC) BLS CPR was also taught and compared with standard BLS CPR (STD). The mean number of chest compressions/minute delivered with AHA BLS CPR was only 43 +/- 1 immediately after initial training and 49 +/- 2 when tested 6 months later. Uninterrupted chest compression BLS resulted in 113 +/- 2 compressions/min delivered immediately after training and 91 +/- 4 six months later (STD versus UCC; P < 0.0001). The mean length of time needed to provide the two breaths during STD-CPR was 14 +/- 1 and 12 +/- 1s (immediately after first training and six months after training). For STD-CPR, the mean minute ventilation was poor immediately after initial training (3.3 +/- 0.3 l/min) and further declined (1.9 +/- 0.4 l/min) at 6 months (P = 0.003). For single rescuer basic cardiopulmonary resuscitation, motivated BLS CPR-trained medical students take nearly as long as previously reported for middle-aged lay individuals to deliver these "two quick breaths". The "Guidelines 2000" recommendation for "two quick breaths" is an oxymoron, as it averages more than 13s. New recommendations for single-rescuer CPR should be considered that emphasize uninterrupted chest compressions.     

Miniaturized mechanical chest compressor: a new option for cardiopulmonary resuscitation

AIM OF STUDY: After cardiac arrest, uninterrupted chest compressions with restoration of myocardial blood flow facilitates restoration of spontaneous circulation. We recognized that this may best be accomplished with a mechanical device and especially so during transport. We therefore sought to develop a lightweight, portable chest compressor which may be carried on the belt or attached to the oxygen tank typically carried on the back of the first response rescuer. A miniaturized pneumatic chest compressor (MCC) weighing less than 2 kg was developed and compared with a currently marketed "Michigan Thumper", which weighed 19 kg. We hypothesized that the 2 kg, low profile, portable device will be as effective as the standard pneumatic Thumper for restoring circulation during CPR. MATERIAL AND METHODS: Ventricular fibrillation was electrically induced in 10 domestic male pigs weighing 39+/-2 kg, and untreated for 5 min. Animals were then randomized to receive chest compressions with either the MCC or the Thumper. After 5 min of mechanical chest compression, defibrillation was attempted with a 150 J biphasic shock. Coronary perfusion pressure (CPP) and end tidal PCO(2) (EtPCO(2)) were measured by conventional techniques together with right carotid artery blood flow (CBF). RESULTS: Four of five animals compressed with the Thumper and each animal compressed with the MCC were successfully resuscitated. No significant differences in CPP, EtPCO(2), CBF and post-resuscitation myocardial function were observed between groups. Resuscitated animals survived for more than 72 h without neurological impairment. CONCLUSION: The low profile, 2 kg miniaturized chest compressor is as effective as the conventional Thumper in an experimental model of CPR.     

Improved hemodynamic performance with a novel chest compression device during treatment of in-hospital cardiac arrest

INTRODUCTION: The purpose of this pilot clinical study was to determine if a novel chest compression device would improve hemodynamics when compared to manual chest compression during cardiopulmonary resuscitation (CPR) in humans. The device is an automated self-adjusting electromechanical chest compressor based on AutoPulse technology (Revivant Corporation) that uses a load distributing compression band (A-CPR) to compress the anterior chest. METHODS: A total of 31 sequential subjects with in-hospital sudden cardiac arrest were screened with institutional review board approval. All subjects had received prior treatment for cardiac disease and most had co-morbidities. Subjects were included following 10 min of failed standard advanced life support (ALS) protocol. Fluid-filled catheters were advanced into the thoracic aorta and the right atrium and placement was confirmed by pressure waveforms and chest radiograph. The coronary perfusion pressure (CPP) was measured as the difference between the aortic and right atrial pressure during the chest compression's decompressed state. Following 10 min of failed ALS and catheter placement, subjects received alternating manual and A-CPR chest compressions for 90 s each. Chest compressions were administered without ventilation pauses at 100 compressions/min for manual CPR and 60 compressions/min for A-CPR. All subjects were intubated and ventilated by bag-valve at 12 breaths/min between compressions. Epinephrine (adrenaline) (1mg i.v. bolus) was given at the request of the attending physician at 3-5 min intervals. Usable pressure signals were present in 16 patients (68 +/- 6 years, 5 female), and data are reported from those patients only. A-CPR chest compressions increased peak aortic pressure when compared to manual chest compression (153 +/- 28 mmHg versus 115 +/- 42 mmHg, P < 0.0001, mean +/- S.D.). Similarly, A-CPR increased peak right atrial pressure when compared to manual chest compression (129 +/- 32 mmHg versus 83 +/- 40 mmHg, P < 0.0001). Furthermore, A-CPR increased CPP over manual chest compression (20 +/- 12 mmHg versus 15 +/- 11 mmHg, P < 0.015). Manual chest compressions were of consistent high quality (51 +/- 20 kg) and in all cases met or exceeded American Heart Association guidelines for depth of compression. CONCLUSION: Previous research has shown that increased CPP is correlated to increased coronary blood flow and increased rates of restored native circulation from sudden cardiac arrest. The A-CPR system using AutoPulse technology demonstrated increased coronary perfusion pressure over manual chest compression during CPR in this terminally ill patient population.     

Two rescuer resuscitation--mission impossible? A pilot study using a manikin setting

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.     

Resuscitation,Prolonged Cardiac Arrest,and an Automated Chest Compression Device

Background: The European Resuscitation Council's 2005 guidelines for cardiopulmonary resuscitation (CPR) emphasize the delivery of uninterrupted chest compressions of adequate depth during cardiac arrest. Objectives: To describe how the circumstances of out-of-hospital cardiac arrest can impede the performance of CPR, and how this situation can be overcome. Case Report: The presentation of two cases of prolonged CPR (48 min and 120 min, respectively) with an automated chest compression device, the AutoPulse^®, under difficult circumstances. Both patients survived without neurological sequelae. Conclusion: Prolonged chest compressions may be necessary in some cardiac arrests. These cases suggest that automated chest compression devices may increase the chance of a favorable outcome in these rare situations.     

Relative effectiveness of interposed abdominal compression CPR: sensitivity analysis and recommended compression rates

Interposed abdominal compression, IAC-CPR incorporates alternating chest and abdominal compressions to generate enhanced artificial circulation during cardiac arrest. The technique has been generally successful in improving blood flow and survival compared to standard CPR; however, some questions remain. OBJECTIVE: To determine "why does IAC-CPR produce more apparent benefit in some subjects than in others?" and "what is the proper compression rate, given that there are actually two compressions (chest and abdomen) in each cycle?" METHOD: Computer models provide a means to search for subtle effects in complex systems. The present study employs a validated 12-compartment mathematical model of the human circulation to explore the effects upon systemic perfusion pressure of changes in 35 different variables, including vascular resistances, vascular compliances, and rescuer technique. CPR with and without IAC was modeled. RESULTS AND CONCLUSIONS: Computed results show that the effect of 100 mmHg abdominal compressions on systemic perfusion pressure is relatively constant (about 16 mmHg augmentation). However, the effect of chest compression depends strongly upon chest compression frequency and technique. When chest compression is less effective, as is often true in adults, the addition of IAC produces relatively dramatic augmentation (e.g. from 24 to 40 mmHg). When chest compression is more effective, the apparent augmentation with IAC is relatively less (e.g. from 60 to 76 mmHg). The optimal frequency for uninterrupted IAC-CPR is near 50 complete cycles/min with very little change in efficacy over 20-100 cycles/min. In theory, the modest increase in systemic perfusion pressure produced by IAC can make up in part for poor or ineffective chest compressions in CPR. IAC appears relatively less effective in circumstances when chest pump output is high.     

The effect of two different counting methods on the quality of CPR on a manikin—A randomized controlled trial

Objectives

To compare the quality of cardiopulmonary resuscitation (CPR) and rescuers’ exhaustion using different methods of counting, and to establish an appropriate method of counting.

Materials and methods

Forty-eight subjects who had received formal training in basic life support (BLS) were recruited from doctors and nurses working in the Emergency Department of a university hospital. They performed 3 min of continuous chest compressions using two different methods of counting, one after the other, on an adult resuscitation manikin. The total number of compressions, the number of these considered satisfactory, the peak heart rate of subjects and the time to peak heart rate were all recorded. Perceived fatigue and discomfort was evaluated by self-reported survey results with use of a visual analogue scale (VAS).

Results

The effective power of external chest compression and the mean compression depth when counting from 1 to 10, repeated three times, were greater than those achieved when counting from 1 to 30 during 3 min of CPR (67.48% vs. 57.81% and 44.52 mm vs. 40.48 mm, P < 0.05). The exhaustion-score using the VAS (22.15 points) was lower and the time to peak heart rate (124.88 s) was longer when counting from 1 to 10, repeated three times, than when rescuers counted from 1 to 30.

Conclusions

Counting from 1 to 10 three times in Chinese as opposed to 1–30 results in better quality chest compressions. Counting from 1 to 10 three times was associated with less user feelings of fatigue, and a longer time to peak heart rate. These findings support the teaching of counting compressions 1–10 three times during CPR.     

Continuous chest compression resuscitation in arrested swine with upper airway inspiratory obstruction

Background

This study was designed to compare 24-h survival rates and neurological function of swine in cardiac arrest treated with one of three forms of simulated basic life support CPR.

Methods

Thirty swine were randomized equally among three experimental groups to receive either 30:2 CPR with an unobstructed endotracheal tube (ET) or continuous chest compression (CCC) CPR with an unobstructed ET or CCC CPR with a collapsable rubber sleeve on the ET allowing air outflow but completely restricting air inflow. The swine were anesthetized but not paralyzed. Two min of untreated VF was followed by 9 min of simulated single rescuer bystander CPR. In the 30:2 CPR group, each set of 30 chest compressions was followed by a 15-s pause to simulate the realistic duration of interrupted chest compressions required for a single rescuer to deliver 2 mouth-to-mouth ventilations. The other two groups were provided continuous chest compressions (CCC) without assisted ventilations. At 11 min post-arrest a biphasic defibrillation shock (150 J) was administered followed by a period of advanced cardiac life support.

Results

In the 30:2 group, 8 of 10 animals had good neurological function at 24-h post-resuscitation. In the CCC open airway group, 10 of 10, and in the CCC inspiratory obstructed group, 9 of 10. The number of shocks (P < 0.05) and epinephrine doses (P < 0.05) required for ROSC was greater in the 30:2 CPR group than in the other two groups.

Conclusions

There were no differences in 24-h survival with good neurological function among these three different CPR protocols.     

Chest Compression and Ventilation Rates during Cardiopulmonary Resuscitation: The Effects of Audible Tone Guidance

Objectives: To determine: 1) whether chest compressions during CPR are being performed according to American Heart Association (AHA) guidelines during cardiac arrest; and 2) the effect of an audio prompt to guide chest compressions on compliance with AHA guidelines and hemodynamic parameters associated with successful resuscitation. Methods: An observational clinical report and laboratory study was conducted. A research observer responded to a convenience sample of cardiac arrests within a 300-bed hospital and counted the rate of chest compressions and ventilations during CPR. To evaluate the effect of an audio prompt on CPR, health care providers performed chest compression without guidance using a porcine cardiac arrest model for 1 minute, followed by a second minute in which audio guidance was added. Chest compression rates, arterial and venous blood pressures, end-tidal CO₂ (ETCO₂) levels, and coronary perfusion pressures were measured and compared for the two periods. Results: Twelve in-hospital cardiac arrests were observed in the clinical part of the study. Only two of 12 patients had chest compressions performed within AHA guidelines. No patient had respirations performed within AHA guidelines. In the laboratory, 41 volunteers were tested, with 66% performing chest compressions outside the AHA standards for compression rate without audible tone guidance. With guided chest compressions, the mean (± SD) chest compression rate increased from 74 ± 22 to 100 ± 3/min (p < 0.01). End-tidal CO₂ levels increased from 15 ± 7 to 17 ± 7 torr (p < 0.01). Coronary perfusion pressure increased minimally with audible tone-guided chest compressions. Conclusions: The majority of Basic Cardiac Life Support-certified health care professionals did not perform CPR according to AHA-recommended guidelines. The use of audible tones to guide chest compression resulted in significantly higher chest compression rates and ETCO₂ levels.     

The quality of chest compressions by trained personnel: the effect of feedback, via the CPREzy, in a randomized controlled trial using a manikin model

Even after training, the ability to perform effective cardiac compressions has been found to be poor and to decrease rapidly. We assessed this ability with and without a non-invasive feedback device, the CPREzy, during a 270s CPR session in an unannounced, single-blinded manikin study using 224 hospital employees and staff chosen at random and using a non-cross over design. The two groups self-assessed their knowledge and skills as adequate. However, the control group (N=111) had significantly more difficulty in delivering chest compressions deeper than 4 cm (25 versus 1 candidate in the CPREzy group), P=0.0001. The control group compressed ineffectively in 36% (+/-41%) of all compressions as opposed to 6+/-13% in the CPREzy group (N=112, P=0.0001). If compressions were effective initially, the time until >50% of compressions were less than 4 cm deep was 75+/-81s in the control group versus 194+/-87 s in the CPREzy group (P=0.0001 [-180 to -57.5]). After a few seconds of training in its use, our candidates used the CPREzy effectively. Against the background knowledge that estimation of compression depth by the rescuer or other team members is difficult, and that performing effective compressions is the cornerstone of any resuscitation attempt, our data suggests that a feedback device such as the CPREzy should be used consistently during resuscitation.     

Quality of chest compressions during compression-only CPR: a comparative analysis following the 2005 and 2010 American Heart Association guidelines

Objective

The latest guidelines both increased the requirements of chest compression rate and depth during cardiopulmonary resuscitation (CPR), which may make it more difficult for the rescuer to provide high-quality chest compression. In this study, we investigated the quality of chest compressions during compression-only CPR under the latest 2010 American Heart Association (AHA) guidelines (AHA 2010) and its effect on rescuer fatigue.

Methods

Eighty-six undergraduate volunteers were randomly assigned to perform CPR according to the 2005 AHA guidelines (AHA 2005) or AHA 2010. After the training course and theoretical examination of basic life support, eight min of compression-only CPR performance was assessed. The quality of chest compressions including rate and depth of compression was analyzed. The rescuer fatigue was evaluated by the changes of heart rate and blood lactate, and rating of perceived exertion.

Results

Thirty-nine participants in the AHA 2005 group and 42 participants in the AHA 2010 group completed the study. Significantly greater mean chest compression depth and compression rate were both achieved in the AHA 2010 group than in the AHA 2005 group. And significantly greater rescuer fatigue was observed in the AHA 2010 group. In addition, the female in the AHA 2010 group could perform the compression rate required by the guidelines, however, significantly shallower compression depth and greater rescuer fatigue were observed when compared to the male.

Conclusions

The quality of chest compressions was significantly improved following the 2010 AHA guidelines, however, it’s more difficult for the rescuer to meet the guidelines due to the increased fatigue of rescuer.     

Prehospital use of minimally invasive direct cardiac massage (MID–CM): a pilot study

BACKGROUND: Internal cardiac compressions are more efficient than closed chest compressions (CCC) in cardiac arrest (CA). AIM OF THE STUDY: To evaluate the prehospital feasibility of performing a new method of minimally invasive direct cardiac massage (MID-CM TheraCardia Inc.). METHODS: Prospective non-randomized open study, after ethical committee approval. Inclusion of 18-85 years old patients in witnessed CA if BLS>5 min and unsuccessful ACLS>20 min after CA. The MID-CM is an atraumatic manual cardiac pumping system deployed in the thoracic cavity through a small incision. Evaluation of: ease of insertion and performing MID-CM, complications, end-tidal CO(2) (PETCO(2)), non invasive arterial blood pressure (NIBP) and return of spontaneous circulation (ROSC). Values are mean+/-SD (min-max). RESULTS: Twenty-five patients included. Mean age 59+/-16 years (26-85); BLS started at 8+/-5 min (0-20), compressions started at 47+/-10 min (29-74) after CA. Dissection and insertion was fast and easy (<1 min). Deployment of the MID-CM was difficult in two patients because of pericardium adhesions and cardiomegaly. In six patients compressions were more difficult because of a 'stone heart' phenomenon. Compressions were possible during ambulance transport of four patients. There was a good palpable carotid pulse in all patients receiving internal compressions. There was a trend in increase of PETCO(2) compared to CCC. NIBP could be measured during MID-CM compressions in 9 patients (systolic>85 mmHg), never during CCC. Seven patients had a ROSC, but only four patients were admitted alive. There was no long term survival. One patient had a serious complication (heart rupture). DISCUSSION: Prehospital use of MID-CM is possible, but it is not comparable to any other resuscitation technique. Training of medical teams is mandatory to obtain good skills and to avoid complications. Further studies are necessary to evaluate efficiency and survival compared to closed chest compressions.     

Quality of external closed-chest compressions in a tertiary pediatric setting: Missing the mark

Introduction

Recent adult reports have demonstrated sub-optimal performance of basic cardiopulmonary resuscitation (CPR) skills in advanced training scenarios and real life arrest situations. We studied the adequacy of chest compressions performed by advanced trained pediatric providers in code scenarios.

Methods

We designed a prospective observational study of pediatric providers performing external closed-chest compressions on a child mannequin that is designed to assess adequacy based on depth and rate of chest compressions. The study was conducted from 2008 to 2009 in which 42 subjects were screened and enrolled for participation. Each subject underwent a basic life support scenario that included two minutes of uninterrupted external closed-chest compressions that were assessed for adequacy based on depth and rate.

Results

For 42 subjects, 168 total 30-s time segments were available for analysis. Chest compressions were performed at a median rate of 110 (interquartile range (IQR) of 75-145) compressions per minute (cpm). No significant decay in rate of chest compressions was noted over the two-minute evaluation. Chest compression depth was adequate in 9.4% of total delivered chest compressions. No statistical significance was found on the job exposure to CPR and delivery of effective chest compressions.

Conclusion

Advanced training of pediatric providers does not ensure adequate delivery of chest compressions. Rate standards and adequate depth of chest compressions are infrequently achieved and both may need more emphasis in CPR training and attention during resuscitations.     

Uninterrupted chest compression CPR is easier to perform and remember than standard CPR

INTRODUCTION: It has long been observed that CPR skills rapidly decline regardless of the modality used for teaching or criteria used for testing. Uninterrupted chest compression CPR (UCC-CPR) is a proposed alternative to standard single rescuer CPR (STD-CPR) for laypersons in witnessed unexpected cardiac arrest in adults. It delivers substantially more compressions per minute and may be easier to remember and perform than standard CPR. METHODS: In this prospective study, 28 medical students were taught STD-CPR and UCC-CPR and then were tested on each method at baseline (0), 6, and 18 months after training. The students' performance for at least 90 s of CPR was evaluated based on video and Laerdal Skillreporter Resusci Anne recordings. RESULTS: The mean number of correct chest compressions delivered per minute trended down over time in STD-CPR (23 +/- 3, 19 +/- 4 , and 15 +/- 3; P = 0.09) but stayed the same in UCC-CPR (43 +/- 9, 38 +/- 7, and 37 +/- 7 = 0.91) at 0, 6, and 18 months, respectively. The mean percentage of chest compressions delivered correctly fell over time in STD-CPR (54 +/- 6%, 35 +/- 6%, and 32 +/- 6%; P = 0.02) but stayed the same in UCC-CPR (34 +/- 5%, 41 +/- 7%, and 38 +/- 8%) at 0, 6, and 18 months, respectively. The number of chest compressions delivered per minute was higher in UCC-CPR at 0, 6, and 18 months (113 versus 44, P < 0.0001; 94 versus 47, P < 0.0001; and 92 versus 44, P < 0.001). The greater number of chest compressions was due to a mean ventilaroty pause of 13-14 s during STD-CPR at all three time points. CONCLUSIONS: Chest compression performance during STD-CPR declined in repeated testing over 18 months whereas there was minimal decline in chest compressions performance on repeated testing of UCC-CPR. In addition, substantially more chest compressions were delivered during UCC-CPR compared to STD-CPR at all time points primarily because of long pauses accompanying rescue breathing.     

A Review of Chest Compression Interruptions During Out-of-Hospital Cardiac Arrest and Strategies for the Future

Background

It has been known for many years that interrupting chest compressions during cardiopulmonary resuscitation (CPR) from out-of-hospital cardiac arrest (OHCA) leads directly to negative outcomes. Interruptions in chest compressions occur for a variety of reasons, including provider fatigue and switching of compressors, performance of ventilations, placement of invasive airways, application of CPR devices, pulse and rhythm determinations, vascular access placement, and patient transfer to the ambulance. Despite significant resuscitation guideline changes in the last decade, several studies have shown that chest compressions are still frequently interrupted or poorly executed during OHCA resuscitations. Indeed, the American Heart Association has made great strides to improve outcomes by placing a greater emphasis on uninterrupted chest compressions. As highly trained health care providers, why do we still interrupt chest compressions? And are any of these interruptions truly necessary?

Objectives

This article aims to review the clinical effects of both high-quality chest compressions and the effects that interruptions during chest compressions have clinically on patient outcomes.

Discussion

The causes of chest compression interruptions are explored from both provider and team perspectives. Current and future methods are introduced that may prompt the provider to reduce unnecessary interruptions during chest compressions.

Conclusions

New and future technologies may provide promising results, but the greatest benefit will always be a well-directed, organized, and proactive team of providers performing excellent-quality and continuous chest compressions during CPR.