Standard Versus Over-the-Head Cardiopulmonary Resuscitation During Simulated Advanced Life Support

Background. Limited space can make rescuer position changes difficult during cardiopulmonary resuscitation (CPR). Over-the-head (OTH) CPR enables one rescuer to deliver chest compressions andventilations without changing position. The aim of the present study was to evaluate quality of OTH versus standard CPR with bag-valve-mask (BVM) ventilation in a manikin model during advanced life support (ALS). Method. In a randomised double-crossover trial, eight paramedic students performed ALS using both OTH andstandard CPR with BVM. Initial rhythm was asystole, converting to ventricular fibrillation after atropine, adrenaline, andCPR. Data collection was stopped after atropine andepinephrine had been given. Data are presented as means ± SD or median with 25% and75% percentile. Results. There were no significant differences in ventilation or compression variables or any time factors with median total hands off times of 50% versus 52% for OTH andstandard CPR respectively. Conclusion. OTH CPR is an alternative method during CPR.     

A Comparison Between Over-The-Head and Standard Cardiopulmonary Resuscitation Performed by Two Rescuers: A Simulation Study

Background: In cardiopulmonary resuscitation (CPR) of a patient with an unsecured airway performed by two health care professionals, two methods are possible: 1) Standard CPR according to the guidelines, with one rescuer performing chest compressions from the side and the other rescuer performing ventilations from over the head of the patient. Additional tasks (like attaching the electrocardiogram and defibrillator) must be performed by the second rescuer during the time between ventilations. 2) Over-the-head CPR, with one rescuer performing chest compressions and ventilations from over the head and the other rescuer performing additional tasks. Objectives: The aim of this study was to compare the quality of CPR achieved by the two methods. Methods: After a standardized theoretical introduction and practical training, 106 medical students with limited knowledge and training in CPR participated in this randomized crossover study. Students performed a 2-min CPR test of standard CPR in both positions and over-the-head CPR alone on a manikin. Results: Standard CPR led to a significantly shorter hands-off-time over a 2-min interval than over-the-head CPR (median 25 s [interquartile range (IQR) 22–26 s] vs. 38 s [IQR 36–43 s], respectively, p < 0.001), and significantly more chest compressions (167 [IQR 158–176] vs. 142 [IQR 132–150], respectively, p < 0.001), more correct chest compressions (72 [IQR 11–136] vs. 45 [IQR 13–88], respectively, p = 0.004), inflations (10 [IQR 10–10] vs. 8 [IQR 8–8], respectively, p < 0.001), and correct inflations (5 [IQR 2–7] vs. 3 [IQR 1–4], respectively, p < 0.001). Conclusions: In the case of a two-professional-rescuer CPR scenario, standard CPR enables a quantitatively better resuscitation than over-the-head CPR.     

Theoretically Optimal Duty Cycles for Chest and Abdominal Compression during External Cardiopulmonary Resuscitation

Objective: To use an electronic model of human circulation to compare the hemodynamic effects of different durations of chest compression during external CPR, both with and without interposed abdominal compression (IAC).
Methods: An electrical analog model of human circulation was studied on digital computer workstations using SPICE, a general-purpose circuit simulation program. In the model the heart and blood vessels were represented as resistive-capacitive networks, pressures as voltages, blood flow as electric current, blood inertia as inductance, and cardiac and venous valves as diodes. External pressurization of the heart and great vessels, as would occur in IAC-CPR, was simulated by the alternate application of damped rectangular voltage pulses, first between intrathoracic vascular capacitances and ground, and then between intra-abdominal vascular capacitances and ground. With this model compression frequencies of 60, 80, and 100 cycles/min and duty cycles ranging from 10% to 90%, both with and without IAC, were compared.
Results: There was little difference in hemodynamics when the overall compression frequency was varied between 60 and 100 cycles/min, but the effects of duty cycle were substantial. During both standard CPR and IAC-CPR, total flow and coronary flow were greatest at chest compression durations equal to 30% of cycle time. Interposed abdominal compression substantially improved simulated systemic blood flow and perfusion pressure at all duty cycles, compared with standard CPR without abdominal compression. Mean arterial pressure > 75 mm Hg and artificial cardiac output > 2.0 L/min could be generated by 30% duty cycle compression with IAC. Coronary perfusion in the model is clearly optimized at 30% chest compression (i.e., high-impulse chest compression technique).
Conclusion: Combined high-impulse chest compressions and IACs maximize blood flow during CPR in the electrical analog model of human circulation.     

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.     

Rescuer Fatigue: Standard versus Continuous Chest-Compression Cardiopulmonary Resuscitation

Objectives Continuous chest‐compression cardiopulmonary resuscitation (CCC‐CPR) has been advocated as an alternative to standard CPR (STD‐CPR). Studies have shown that CCC‐CPR delivers substantially more chest compressions per minute and is easier to remember and perform than STD‐CPR. One concern regarding CCC‐CPR is that the rescuer may fatigue and be unable to maintain adequate compression rate or depth throughout an average emergency medical services response time. The specific aim of this study was to compare the effects of fatigue on the performance of CCC‐CPR and STD‐CPR on a manikin model. Methods This was a prospective, randomized crossover study involving 53 medical students performing CCC‐CPR and STD‐CPR on a manikin model. Students were randomized to their initial CPR group and then performed the other type of CPR after a period of at least two days. Students were evaluated on their performance of 9 minutes of CPR for each method. The primary endpoint was the number of adequate chest compressions (at least 38 mm of compression depth) delivered per minute during each of the 9 minutes. The secondary endpoints were total compressions, compression rate, and the number of breaks taken for rest. The students' performance was evaluated on the basis of Skillreporter Resusci Anne (Laerdal, Wappingers Falls, NY) recordings. Primary and secondary endpoints were analyzed by using the generalized linear mixed model for counting data. Results In the first 2 minutes, participants delivered significantly more adequate compressions per minute with CCC‐CPR than STD‐CPR, (47 vs. 32, p = 0.004 in the 1st minute and 39 vs. 29, p = 0.04 in the 2nd minute). For minutes 3 through 9, the differences in number of adequate compressions between groups were not significant. Evaluating the 9 minutes of CPR as a whole, there were significantly more adequate compressions in CCC‐CPR vs. STD‐CPR (p = 0.0003). Although the number of adequate compressions per minute declined over time in both groups, the rate of decline was significantly greater in CCC‐CPR compared with STD‐CPR (p = 0.0003). The mean number of total compressions delivered in the first minute was significantly greater with CCC‐CPR than STD‐CPR (105 per minute vs. 58 per minute, p < 0.001) and did not change over 9 minutes in either group. There were no differences in compression rates or number of breaks between groups. Conclusions CCC‐CPR resulted in more adequate compressions per minute than STD‐CPR for the first 2 minutes of CPR. However, the difference diminished after 3 minutes, presumably as a result of greater rescuer fatigue with CCC‐CPR. Overall, CCC‐CPR resulted in more total compressions per minute than STD‐CPR during the entire 9 minutes of resuscitation.     

Determination of advanced life support knowledge level of residents in a Turkish university hospital

The aim of the study was to determine the advanced cardiac life support (ACLS) knowledge level of residents and related factors in the departments of Anesthesiology, Emergency Medicine, Internal Medicine, and Cardiology in a university hospital. For this cross-sectional study, a total of 20 multiple-choice questions were prepared concerning several different topics, including: fatal dysrhythmias, oxygenation, ventilation and airway control, asystole, and pulseless electrical activity. Questions were given to residents before their periodic training meetings and collected in 30 min. There were 101 of 120 residents from four clinical departments (participation rate 84%) tested. Average point total and standard deviations of all residents were 66.3 +/- 17 out of 100 points. On a departmental basis, statistically significant differences were found in the knowledge level of residents (Emergency Medicine: 86.2 +/- 8.2, Cardiology: 66.7 +/- 12.9, Anesthesiology: 59.3 +/- 16.2, Internal Medicine: 56.1 +/- 13.5, F: 28.6, p < 0.0001). The factors that affect ACLS knowledge level of residents were "postgraduate ACLS training," "awareness of guidelines," and "resuscitation frequency." Postgraduate training and the frequency of ACLS practice seem to increase the ACLS knowledge level of residents. The present study emphasizes the necessity for a standardized systematic postgraduate ACLS training program for the residents of related medical disciplines. Further studies with larger groups are needed to investigate theoretical knowledge, resuscitation skill competency, and related factors.     

Socioeconomic Status Is Associated with Provision of Bystander Cardiopulmonary Resuscitation

Objective. Although socioeconomic status (SES) has been linked to multiple health outcomes, there have been few studies of the effect of SES on the provision of bystander cardiopulmonary resuscitation (CPR) during cardiac arrest events and no studies that we know of on the effect of SES on the provision of dispatcher-assisted bystander CPR. This study sought to define the relationship between SES and the provision of bystander CPR in an emergency medical system that includes dispatcher-provided CPR instructions. Methods. This study was a retrospective, cohort analysis of cardiac arrests due to cardiac causes occurring in private residences in King County, Washington, from January 1, 1999, to December 31, 2005. We used the tax-assessed value of the location of the cardiac arrest as an estimate of the SES of potential bystanders as well as multiple measures from 2000 Census data (education, employment, median household income, and race/ethnicity). We also examined the effect of patient and system characteristics that may affect the provision of bystander CPR. Logistic regression models were used to analyze the association of these factors with two outcomes: the provision of bystander CPR with and without dispatcher assistance. Results. Forty-four percent (1,151/2,618) of cardiac arrest victims received bystander CPR. Four hundred fifty-seven people (17.5% of the entire study population, 39.7% of those who received any bystander CPR) received CPR without telephone instructions. A total of 694 people received dispatcher-assisted bystander CPR (25.6% of the entire population, 60.4% of those receiving any bystander CPR). After adjusting for demographic and care factors, we found a strong association between the tax-assessed value of the cardiac arrest location and increased odds of the provision of bystander CPR without dispatcher instructions and bystander CPR with dispatcher assistance compared with no bystander CPR. Conclusions. This study suggests that higher bystander SES is associated with increased rates of bystander CPR with and without dispatcher instructions. CPR training programs that target lower-SES communities and assessment of these training methods may be warranted.     

Compression of the Left Ventricular Outflow Tract During Cardiopulmonary Resuscitation

Objectives:  This prospective observational study was performed to investigate if the hand position used for external chest compressions is in an optimal position for compressing the ventricles during standard cardiopulmonary resuscitation (CPR).
Methods:  Transesophageal echocardiography (TEE) was performed during standard CPR in 34 patients with nontraumatic cardiac arrest (24 males, mean ± standard deviation [SD] age = 56 ± 12 years). On the recorded image of TEE, an area of maximal compression (AMC) was identified, and the degree of compression at the AMC and the left ventricular stroke volume was calculated.
Results:  A significant narrowing of the left ventricular outflow tract (LVOT) or the aorta was noted in all patients, with the degree of compression at the AMC ranging from 19% to 83% (mean ± SD = 49 ± 19%). The AMC was found at the aorta in 20 patients (59%) and at the LVOT in 14 patients (41%). A significant narrowing of more than 50% of the diameter at the end of the relaxation phase occurred in 15 patients (44%). On linear regression, the left ventricular stroke volume was correlated with the location of the AMC (R² = 0.165, p = 0.017).
Conclusions:  The outflow of the left ventricle is affected during standard CPR, resulting in varying degrees of narrowing in the LVOT and/or the aortic root.     

Vasopressin Can Increase Coronary Perfusion Pressure during Human Cardiopulmonary Resuscitation

Objectives : To determine the hemodynamic effect of vasopressin on coronary perfusion pressure (CPP) in prolonged human cardiac arrest.
Methods : A prospective, open-label clinical trial of vasopressin during cardiac resuscitation was performed. Ten patients presenting in cardiac arrest initially received resuscitative measures by emergency physicians according to Advanced Cardiac Life Support (ACLS) gcidelines. A central venous catheter for fluid and drug administration and a femoral artery catheter for measurement of CPP (aortic minus right atrial relaxation phase pressures) were placed. When each patient was deemed nonsalvageable, 1.0 mg epinephrine was given and CPP was measured for 5 minutes, followed by a dose of vasopressin (1.O Ukg). CPP measurements were continued for another 5 minutes.
Results : The mean duration of cardiac arrest (out-of-hospital interval plus duration of ED ACLS) was 39.6 ± 16.5 min. There was no improvement in CPP after 1.0 mg of epinephrine. Vasopressin administration resulted in a significant increase of CPP in 4 of the 10 patients. Patients responding to vasopressin had a mean increase in CPP of 28.2 ± 16.4 mm Hg (range: 10–51.5), with these peak increases occurring at 15 seconds to 4 minutes after administration. The increases in the vasopressin levels after administration did not differ between the responders and nonresponders.
Conclusions : In this human model of prolonged cardiac arrest, 40% of the patients receiving vasopressin had a significant increase in CPP. This pilot study suggests that investigation of earlier use of vasopressin as a therapeutic alternative in the treatment of cardiac arrest is warranted.     

Hemodynamics, Survival Benefits, and Complications of Interposed Abdominal Compression during Cardiopulmonary Resuscitation

Objective: To review and describe the hemodynamics and mechanism of benefit of interposed abdominal compression cardiopulmonary resuscitation (IAC-CPR) as well as the current complications and survival data withtheuseoflAC-CPR.
Methods: Critical review of selected, published English-language studies analyzing IAC-CPR. Overview of hemodynamic effects, complications, and survival data of IAC-CPR vs standard CPR.
Results: Several investigators have demonstrated improvements in coronary perfusion pressure, carotid and cerebral blood flows, and augmented venous return using IAC-CPR compared with standard CPR. Recently, IAC-CPR has been shown to improve survival from in-hospital cardiac arrest. To date, there has been no increase in complications seen with the use of abdominal compression during CPR.
Recommendations: IAC-CPR should be considered an adjunct to standard CPR for adult patients experiencing in-hospital cardiac arrest, after an adequate airway has been secured. More research is needed before IAC-CPR can be recommended for out-of-hospital cardiac arrest, for patients who have not been intubated, or for children.     

Hemodynamics of Interposed Abdominal Compression during Human Cardiopulmonary Resuscitation

Objective: Clinical studies of interposed abdominal compression CPR (IAC-CPR) have had diverse outcomes. This study compared the hemodynamics of standard CPR and IAC-CPR in humans.
Methods: A 24-month prospective nonrandomized analysis of hemo-dynamic parameters was performed in a convenience cohort of 20 adults who had had out-of-hospital, nontraumatic, normothermic cardiac arrests. The study took place in the resuscitation unit of a large urban hospital. Thoracic aortic and right atrial catheters were inserted and pressures were recorded during standard CPR and IAC-CPR. Coronary perfusion pressures (CPPs) were determined during standard CPR and IAC-CPR. The patients were separated into two groups based upon their responses to IAC-CPR. Responders had increases in CPP during IAC-CPR; nonresponders had decreases or no change in CPP during IAC-CPR. Aortic relaxation, right atrial relaxation, aortic compression, and right atrial compression phase pressures were compared between the two groups.
Results: CPPs increased in 13 patients and decreased in seven patients. The mean change in CPP with IAC-CPR was an increase of 5.8 ± 15.1 torr. An elevated right atrial compression phase pressure (RaComp) during standard CPR was predictive of an increase in CPP during IAC-CPR (p = 0.047). In those patients who showed improvements in CPP during IAC-CPR, mean aortic relaxation phase pressures (AoRelax) increased by 9.5 ± 14.2 torr (p = 0.026) and mean right atrial relaxation phase pressures (RaRelax) decreased by 2.6 ± 6.2 torr (p = 0.099) during IAC-CPR.
Conclusions: The variable effects of IAC-CPR on CPP appear to be multifactorial. The improvement in CPP that occurred in responders to IAC-CPR was secondary to an increase in AoRelax as well as a decrease in RaRelax.     

The Evolution of Abdominal Compression in Cardiopulmonary Resuscitation

Objective: To review the history of external abdominal compression as an adjunct to cardiopulmonary resuscitation (CPR), tracking the development of five major themes over the course of the 20th century: 1) augmentation of peripheral resistance by physical means, 2) risk of hepatic injury with abdominal compression, 3) counterpulsation vs sustained compression, 4) the abdominal pump mechanism, and 5) contact compression techniques.
Methods: Literature retrieved from successive MEDLINE English-language searches was reviewed with a special emphasis on work and concepts highlighted by participants at the First Purdue Conference on Interposed Abdominal Compression-CPR, September 1992.
Results: External abdominal compression of one form or another has been studied as a means of resuscitation by many investigators throughout the 20th century. Experimental and clinical studies have shown generally consistent evidence of hemodynamic augmentation by abdominal compression during various forms of CPR. Recent advances include a modified theoretical understanding of hemodynamic mechanisms and demonstration of clinical potential in humans. Inconsistencies in published results may be due to differences in mechanical techniques of abdominal compression. Based on these studies, a modified manual technique for "contact compression" of the abdominal aorta is recommended.
Conclusions: A technique for left-of-center, angled compression of the abdominal aorta against the crest of the spine is recommended. Further well-supervised and controlled clinical trials using this standardized technique are warranted as a prelude to more widespread clinical application of abdominal compression in CPR.     

Who Gets Bystander Cardiopulmonary Resuscitation in a Witnessed Arrest?

Objective: To identify characteristics associated with provision of bystander CPR in witnessed out-of-hospital cardiac arrest cases.
Methods: An observational, prospective, cohort study was performed using cardiac arrest cases as identified by emergency medical services (EMS) agencies in Oakland County, MI, from July 1, 1989, to December 31, 1993. All patients who sustained a witnessed arrest prior to arrival of EMS personnel were reviewed.
Results: Of the 927 patients meeting entry criteria, the 229 patients receiving bystander CPR were younger: 60.9 ± 14.7 vs 67.9 ± 14.7 years (p < 0.01). Most (76.6%) cardiac arrests occurred in the home. In a multivariate logistic model, only the location of arrest outside the home was a significant predictor of receiving bystander CPR [odds ratio (OR) 3.8; 99% CI 2.5, 5.9]. Arrests outside the home were associated with significantly improved outcome, with 18.2% of out-of-home and 8.2% of in-home victims discharged from the hospital alive (OR 2.5; 99% CI 1.4, 4.4).
Conclusion: Patients who have had witnessed cardiac arrests outside the home are nearly 4 times more likely to receive bystander CPR, and are twice as likely to survive. This observation emphasizes the need for CPR training of family members in the authors' locale. This phenomenon may also represent a significant con-founder in studies of out-of-hospital cardiac arrest and resuscitation.     

The utility of the HeartSaver Sticker for maintaining correct hand position during chest compressions

Background

The importance of attaining correct hand position in cardiopulmonary resuscitation (CPR) instruction has not been emphasized as much as the significance of the compression performance. Study Objectives: This pilot study was performed to investigate the utility of a HeartSaver Sticker for maintaining correct hand position during chest compressions.

Methods

Fifty-one sophomore college students, training to become emergency medical technicians, were recruited. The students, having no previous experience using HeartSaver stickers, participated in this prospective, randomized simulation-based controlled study, which consisted of two groups: 1) with sticker (n = 26), 2) without sticker (n = 25). The 4 × 4-cm HeartSaver sticker marked with both vertical and horizontal center lines was used in this study. Proper sticker placement was such that the vertical line coincided with the mid-sternum of the chest, and the horizontal line aligned with the nipples. Participants performed adult basic life support by single rescuer according to the 2005 American Heart Association resuscitation guidelines. Skill assessment was also performed by these guidelines.

Results

Group 1 participants placed the HeartSaver sticker on the correct landmark within 10 s of approaching the model. The compression rate and depth were not significantly different between the two groups. However, significant improvement in correct hand position was noticed when using the HeartSaver sticker. Correct hand position was 97.1% ± 7.4% in group 1 and 85.9% ± 21.5% in group 2 (p = 0.002).

Conclusion

The HeartSaver sticker was useful in maintaining correct hand position during the single-rescuer CPR scenario because it provided easy recognition of that position when compressing after ventilations.     

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.     

Real-Time Cardiopulmonary Resuscitation Feedback and Targeted Training Improve Chest Compression Performance in a Cohort of International Healthcare Providers

BackgroundOptimal cardiopulmonary resuscitation (CPR) performance is the foundation of successful cardiac arrest resuscitation. However, health care providers perform inadequate compressions. Better training techniques and real-time CPR feedback may improve compression performance.ObjectiveWe sought to evaluate the impact of a targeted training program combined with real-time defibrillator CPR feedback on chest compression performance in an international cohort of health care providers.MethodsPhysicians, nurses, respiratory therapists, and technicians from 6 hospitals in 5 countries (Taiwan, Singapore, China, Bahrain, and Kuwait) participated in a standardized resuscitation workshop. Chest compression was measured before and after didactics and activation of CPR feedback. Compressions were performed for 1 min on standard CPR manikins placed on a hospital bed and backboard and measured using ZOLL R Series defibrillators. The percentage of compressions meeting target values for depth and rate were compared before and after the workshop and activation of real-time CPR feedback. No depth maximum was defined to allow for mattress compression.ResultsChest compressions were more likely to meet targets for depth (71–95%, odds ratio [OR] 8.61 [95% confidence interval {CI} 4.42–16.77], p < 0.001), rate (41–81%, OR 6.4 [95% CI 4.2–9.8], p < 0.001), and both depth and rate (5–42%, OR 2.4 [95% CI 6.7–22.9], p < 0.001) after the workshop and activation of real-time CPR feedback.ConclusionsA targeted training intervention combined with real-time CPR feedback improved chest compression performance among health care providers from various countries.     

Rescuer Fatigue in the Elderly: Standard vs. Hands-only CPR

Background

Hands-only cardiopulmonary resuscitation (HO-CPR) is recommended as an alternative to standard CPR (STD-CPR). Studies have shown a degradation of adequate compressions with HO-CPR after 2 min when performed by young, healthy medical students. Elderly rescuers' ability to maintain an adequate compression rate and depth until emergency medical services (EMS) arrives is unknown.

Objectives

The specific aim of this study was to compare elderly rescuers' ability to maintain adequate compression rate and depth during HO-CPR and STD-CPR in a manikin model.

Methods

In this prospective, randomized crossover study, 17 elderly volunteers performed both HO-CPR and STD-CPR, separated by at least 2 days, on a manikin model for 9 min each. The primary endpoint was the number of adequate chest compressions (> 38 mm) delivered per minute. Secondary endpoints were total compressions, compression rate, and the number of breaks taken for rest.

Results

There was no difference in the number of adequate compressions between groups in the first minute; however, the STD-CPR group delivered significantly more adequate chest compressions in minutes 2–9 (p < 0.05). The total number of compressions delivered was significantly greater in the HO-CPR than STD-CPR group when considering the entire resuscitation period. A significantly greater number of rescuers took breaks for rest during HO-CPR than STD-CPR.

Conclusions

Although HO-CPR resulted in a greater number of overall compressions than STD-CPR, STD-CPR resulted in a greater number of adequate compressions in all but the first minute of resuscitation.