Two-rescuer Cardiopulmonary Resuscitation Research Articles

Accuracy of two-rescuer adult CPR performed by medical registrars at a South African university.

Cardiopulmonary resuscitation (CPR) is performed to manually keep brain function intact until the patient's spontaneous blood circulation and breathing are restored. In South Africa, registrars, who are qualified doctors training to specialise in a medical field, are usually the team leaders and oversee junior doctors and nurses during resuscitation. This study aimed to determine the accuracy of the execution of two-rescuer adult CPR on a Resusci-Anne® manikin performed by registrars from the University of the Free State, South Africa. A cross-sectional study was conducted. From a target population of 142 registrars, 47 participated, of whom 44 were included in the analysis. During five cycles of CPR, compression quality was assessed. During a subsequent five cycles, airway management was assessed. Participants were evaluated executing CPR on the Resusci-Anne® manikin, with a recently Basic Life Support trained student researcher as second rescuer. A modified version of the American Heart Association's tick sheet for two-rescuer adult CPR was completed by two student researchers. Department, gender and the date of the most recent CPR training attended were recorded. The median total percentage score was 82.2% (range 33.3% to 100.0%). Results showed that 88.6% of registrars consistently demonstrated correct hand placement, 25.0% correct compression rate, 93.2% correct compression depth, and 61.4% allowed complete chest recoil during compressions. Consistently correct E-C technique was found in 77.3%, and correct ventilation rate in 93.2%. Only 63.6% correctly managed an open airway, and 61.4% achieved visible chest rise. A consistently correct compression-to-ventilation ratio was performed by 59.1% of registrars. The study found that registrars were not consistently performing high-quality CPR on a Resusci-Anne® manikin and identified areas needing attention. The results of this study highlight the need for compulsory CPR training and regular fire drills for registrars.

Modified Two-Rescuer CPR With a Two-Handed Mask-Face Seal Technique Is Superior To Conventional Two-Rescuer CPR With a One-Handed Mask-Face Seal Technique

Bag-valve-mask (BVM) ventilation using a two-handed mask-face seal has been shown to be superior to a one-handed mask-face seal during cardiopulmonary resuscitation (CPR). We aimed to compare CPR quality metrics during simulation-based two-rescuer CPR with a modified two-handed mask-face seal technique and two-rescuer CPR with the conventional one-handed mask-face seal technique. Participants performed two-rescuer CPR on a simulation manakin and alternated between the modified and conventional CPR methods. For the modified method, the first rescuer performed chest compressions and thereafter squeezed the BVM resuscitator bag during the ventilatory pause, while the second rescuer created a two-handed mask-face seal. For the conventional method, the first rescuer performed chest compressions and the second rescuer thereafter delivered rescue breaths by creating a mask-face seal with one hand and squeezing the BVM resuscitator bag with the other hand. Among the 40 participants that were enrolled, the mean ± standard deviation (SD) delivered respiratory volume was significantly higher for the modified two-rescuer method (319.4 ± 71.4 mL vs. 190.2 ± 50.5 mL; p < 0.0001). There were no statistically significant differences between the two methods with regard to mean ± SD compression rate (117.05 ± 9.67 compressions/min vs. 118.08 ± 10.99 compressions/min; p = 0.477), compression depth (52.80 ± 5.57 mm vs. 52.77 ± 6.77 mm; p = 0.980), chest compression fraction (75.92% ± 2.14% vs. 76.57% ± 2.57%; p = 0.186), and ventilatory pause time (4.62 ± 0.64 s vs. 4.56 ± 0.43 s; p = 0.288). With minor modifications to the conventional method of simulated two-rescuer CPR, rescuers can deliver significantly higher volumes of rescue breaths without compromising the quality of chest compressions.

Feasibility of a Modified Strategy for 2-Rescuer Cardiopulmonary Resuscitation.

Cardiopulmonary resuscitation (CPR) requires effective chest compressions and ventilations to circulate and oxygenate blood. It has been established that a 2-handed mask seal is superior when providing bag-valve-mask (BVM) ventilations. However a 1-handed technique remains the standard with which health care providers are trained to perform 2-rescuer CPR. We sought to determine if a modified 2-rescuer CPR technique that incorporates a 2-handed mask seal during ventilations can be accomplished without compromising chest compression quality during a simulated cardiac arrest. Medical student volunteers were divided into an "intervention" arm, with 1 rescuer creating a 2-handed mask seal and the second rescuer performing chest compressions followed by that second rescuer squeezing the BVM bag to deliver ventilations during compression pauses, and a "control" arm, in which standard 2-rescuer CPR was performed. Both arms received a brief CPR refresher following a standard script. The 2 rescuer teams then performed 2 rounds of CPR on a manikin while being video recorded. Data were collected from real-time evaluation and post hoc video analysis. Forty-seven pairs of students enrolled in the study. There were no statistically significant differences between the intervention and control arms for median (interquartile range [IQR]) compression fraction (72% [69.5-75.7%] vs. 73.2% [69.1-76.1%]; p=1.0), median time to complete 2 rounds of CPR (207.8s [198.5-222.9s] vs. 214.7s [201.3-219.5s]; p=0.625), median hands-off time (49.8s [46.2-63.0s] vs. 55.4s [50.4-65.2s]; p=0.278), or median time for 30 compressions (15.2s [14.3-15.9s] vs. 15.4s [14.6-16.3s]; p=0.452). Two-rescuer CPR incorporating a 2-handed face mask seal can be performed effectively without impacting chest compression quality during simulated cardiac arrest.

Influence of rescuer strength and shift cycle time on chest compression quality

Introduction. Previous studies have sug-gested that differences in rescuer strength and compression shift cycle are strongly associated with the quality of chest com-pression. We hypothesised that changing the shift cycle from two minutes to one would have a positive effect on the qual-ity of chest compression in two-rescuer cardiopulmonary resuscitation (CPR), re-gardless of rescuer strength.Methods.Thirty-nine senior medical stu-dents participated in this prospective, simulation-based, crossover study. Af-ter evaluation of muscle strength using a handgrip dynamometer, each participant was required to perform two sets of com-pressions separated by a 15-minute rest. Participants started with either four cycles of chest compressions for one minute fol-lowed by a one-minute rest (1-MCS), or with two cycles of chest compressions for two minutes followed by a two-minute rest (2-MCS). After a 15-minute break, participants switched groups and per-formed the other set of compressions. Mean compression depth (MCD), mean adequate compression (MAC), and ade-quate compression ratio (ACR) per minute were measured for each group. Subjective fatigue was reported after the completion of each set of compression cycles. Results. Rescuer strength was strongly correlated with MCD (p <0.01), MAC ratio (p <0.01), and ACR (p <0.01), and cycle group was correlated with MCD (p <0.01) and ACR (p =0.03). Subjective fatigue with 1-MCS was lower than with 2-MCS, regardless of rescuer strength.Conclusion. We found that the quality of chest compressions could be improved by changing the shift cycle from two min-utes to one, regardless of rescuer strength. Therefore, reducing the existing shift cycle recommended in guidelines for two rescu-ers could be beneficial.

2인구조자 심폐소생술 시 환기방법에 따른 가슴압박 중단시간의 비교: 일개 대학병원 간호사를 대상으로

Purpose: This study aimed to compare the effects of rescue ventilation maneuvers on the quality of two-rescuer cardiopulmonary resuscitation (CPR). Methods: We implemented mouth to mouth (MMV), mouth to pocket mask (MPV) and bag-valve mask ventilation (BMV) maneuvers. Each team of two-nurses was randomized to perform three consecutive sessions of two-rescuer CPR by using three artificial ventilation maneuvers. Results: The subjects were 26 teams of nurses (female: 96.2%, male: 3.8%, age: 26.6 years). Failed ventilation was more frequent in BMV (, p ) and MPV (). BMV had more compressions per minute () than MMV (, p

Physicians' Knowledge of Cardiopulmonary Resuscitation Guidelines and Current Certification Status at the University Hospital of the West Indies, Jamaica.

To determine physicians' knowledge of cardiopulmonary resuscitation (CPR) guidelines at the University Hospital of the West Indies (UHWI), Jamaica, and their current certification status in basic life support (BLS), advanced cardiac life support (ACLS), paediatric advanced life support (PALS) and advanced trauma life support (ATLS). This was a cross-sectional study. A 23-item self-administered questionnaire was used to assess physicians practising at the UHWI, from the Departments of Anaesthesia, Surgery, Internal Medicine, Accident and Emergency, Obstetrics and Gynaecology and Oncology. One hundred and forty-three (65%) of the targeted 220 physicians responded. There were 77 (55%) females and 41% of respondents were between ages 26 and 30 years. Knowledge of CPR guidelines was inadequate, as the median score obtained was 4.0 (interquartile range [IQR] 2-5) out of a possible eight. Physician seniority was inversely related to knowledge scores (p < 0.01). While 86% of all respondent physicians had been trained in BLS, only 46% were certified at the time of the study. Fewer (52%) were trained in ACLS with only 36% currently certified. Only 65% had been trained in the use of a defibrillator. Most knew the correct compression rate (78%), but only 46% knew the compressions to breaths ratio for both single and two-rescuer CPR. Only 42% of anaesthetists and 27% of emergency physicians were currently ACLS certified. Physician knowledge of CPR protocols was suboptimal and current certification levels were low. Increased training and recertification is necessary to improve physician knowledge which is expected to result in improved performance of CPR.

Optimum location for chest compressions during two-rescuer infant cardiopulmonary resuscitation

Objectives The study aims to evaluate the optimal chest compression site in two-rescuer infant cardiopulmonary resuscitation (CPR). Methods Charts and multidirectional computed tomography images of infants who presented to one of four hospitals from March 2004 to March 2009 were reviewed retrospectively. The length of the sternum ( S total), the length and width ( L, W) of adult thumbs after two thumbs were placed side-by-side were measured. The study included the structures located underneath the lower third of S total ( S total/3), the lower half of S total ( S total/2), the sternum at the inter-nipple line ( S n), the point of maximal anterior–posterior heart diameter ( S m), the lower margin of L and the lateral margin of W from S total/3, S total/2, S n and S m. Results Of the 75 infants enrolled, the ratio of the length from the xiphoid process to S m from S total was 0.24 ± 0.19. In the population studied, 43.1% had aortic roots in S total/2, 44.0% had left ventricular outflow tracts in S total/3, 46.7% had left ventricular outflow tracts at S n and 100.0% had left ventricles at S m. All the infants had livers in the lower margin of L from S m and all of them had hearts in the left lateral margin of half of W from S m. A total of 42.7% had lungs in the right lateral margin of half of W from S m. Conclusion The left ventricle was located in the lower quarter of the sternum, lower than S total/3. However, more studies are needed to validate the efficiency and safety of compressing the lower quarter of the sternum in two-rescuer infant CPR.

Chest compressions by ambulance personnel on chests with variable stiffness: Abilities and attitudes

Quality of cardiopulmonary resuscitation (CPR) performed by professionals is reported to be substandard even with automated corrective feedback. We hypothesised that lack of quality is not due to physical capabilities. Eighty ambulance personnel from the same services where the quality of clinical CPR was investigated, performed two-rescuer CPR with similar corrective feedback for 5min on each of four manikins with different chest stiffness. The personnel also scored their agreement with statements on clinical CPR performance. All study subjects performed CPR well within Guidelines recommendations on all four manikins with mean compression depth 44+/-3mm, compression rate 101+/-3min(-1), and 7+/-2 ventilations per minute. Three quarters stated that during CPR on patients their personal sense of correct depth and force determined their performance. Fifty-five percent believed that too deep chest compressions could cause serious injury to the patient, and 39% that compressing to Guidelines recommended depth may often result in severe patient injury. A quarter felt that the potential benefits of compressing to the Guidelines depth could not justify the injuries it would cause. Breaking ribs made 54% feel very uncomfortable. Ambulance personnel were physically capable of consistently compressing to the Guidelines depth even on the stiffest chest. These laboratory results cannot be directly compared to the clinical out-of-hospital ALS situation, but strongly indicate that the inadequate chest compressions found in our clinical study were not due to lack of physical capability. We speculate that this may at least partly be explained by their fear of causing patient injury and trust in their own opinion of what is the correct compression depth and force in preference to the feedback.

A Randomized, Controlled Comparison of Cardiopulmonary Resuscitation Performed on the Floor andon a Moving Ambulance Stretcher

Background. Recent studies have demonstrated that cardiopulmonary resuscitation (CPR) of poor quality is associated with worsened outcomes. Objective. To compare the quality of CPR delivered on the floor with the quality of CPR delivered on a moving stretcher. The authors hypothesized that CPR performed on the floor would be superior to that performed on a moving stretcher. Methods. A randomized, crossover experimental design was used. Subjects included emergency medical technician students, paramedic students, andemergency medicine residents. Two-member teams were randomly assigned to perform two-rescuer CPR on a manikin either on the floor or on a moving stretcher. After a 5-minute rest, the teams performed CPR under the opposite condition. Compression andventilation data were collected using a recording resuscitation manikin. Dependent variables were compression depth, compression rate per minute, percentage of correct chest compressions, tidal volume, andpercentage of correct ventilations. Data were compared using two-tailed paired t-test. Results. Sixty-two subjects completed the study. The mean compression depth performed on the floor (39 ± 9 mm) was greater than that on a moving stretcher (28 ± 9 mm) (p < 0.001). The mean rates of chest compressions on the floor (110 ± 17 beats/min) andon a moving stretcher (113 ± 21 beats/min) were not different (p = 0.49). The percentage of correct compressions performed on the floor (54% ± 40%) exceeded that on a moving stretcher (21% ± 29%)(p < 0.001). The percentage of correct ventilations performed on the floor (43% ± 26%) was greater than that on a moving stretcher (24% ± 21%)(p < 0.04). Conclusions. Chest compression andventilation quality of CPR performed on the floor was superior to that of CPR performed on a moving stretcher in this manikin model. The quality of CPR while moving was significantly compromised.

Over-the-Head Cardiopulmonary Resuscitation Improves Efficacy in Basic Life Support Performed by Professional Medical Personnel with a Single Rescuer: A Simulation Study

Two-rescuer cardiopulmonary resuscitation (CPR) is considered the best method for professional basic life support (BLS). However, in many prehospital cardiac arrest situations, one rescuer has to begin CPR alone while the other performs additional tasks. In theory, over-the-head CPR is a suitable alternative in this situation, with the added benefit of allowing the single rescuer to use a self-inflating bag for ventilation. In this trial, we compared standard single-rescuer CPR with over-the-head CPR in manikins. We planned this study using a crossover study design where each participant administered both CPR techniques in a randomized order. Ventilation and chest compression data were collected with analysis software during a 2-min CPR test for each technique. Sixty-seven emergency medical technician students participated in this trial. Over-the-head CPR allowed for superior ventilation compared to standard CPR (number of correct ventilations: 330 of 760 versus 279 of 779; P = 0.002). The quality of delivered chest compressions did not differ between the two groups (correct chest compressions: 4293 of 6304 versus 4313 of 6395; P = 0.44). In conclusion, our study has shown that over-the-head CPR may be an effective alternative BLS technique when a single professional rescuer has to perform CPR, likely offering superior ventilation and comparable chest compression quality compared with standard BLS.

Two-rescuer CPR results in hyperventilation in the ventilating rescuer

The “Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care – International Consensus on Science” recommend a tidal ventilation volume of 10 ml/kg body-weight without the use of supplemental oxygen during two-rescuer adult cardiopulmonary resuscitation (CPR). This relates to a ventilation volume of about 6.4 l/min. Additionally, the first aid provider ventilating the victim will breathe for him/herself during the external chest compression period adding another 3.2 l/min of ventilation. Finally, a deep breath is recommended before each ventilation to increase the end-expiratory oxygen concentration of the air exhaled. To investigate the effects of these recommendations, 20 healthy volunteers were asked to perform two-rescuer CPR in a lung model connected to a BLS-manikin. End-tidal carbon dioxide, oxygen saturation, and heart rate were recorded continuously. Capillary blood gas samples were collected and non-invasive blood pressure was recorded prior to the start of external chest compressions and immediately after the end of each measurment period. Furthermore, hyperventilation related symptoms reported by the volunteers were also recorded. The data reveal a significant decrease in capillary and end-tidal carbon dioxide pressure in the volunteers ( P < 0.001). Additionally, in 75% of test persons multiple hyperventilation associated symptoms occurred. Ventilation during two-rescuer CPR performed according to the Guidelines 2000 may cause injury to the health of first aid providers. To minimize hyperventilation, both rescuers should exchange their positions at intervals of 3–5 min. These data challenge the recommendation to take a deep breath prior to each ventilation.

Modification of the closed circuit underwater breathing apparatus LAR V makes it suitable for cardiopulmonary resuscitation (CPR)

This pilot study was carried out in order to determine whether or not a modified closed circuit underwater oxygen rebreathing device could serve as an adjunct for ventilation during CPR in remote locations. As a control a common self-inflating bag valve ventilation device was used. Methods: A total of 20 combat divers were enrolled, of whom 18 met the criteria to be included in two-rescuer CPR manikin training. A modified LAR V (Dräger, Germany), a closed circuit underwater breathing apparatus, that uses pure oxygen, and a conventional Ambu® Mark III bag were used for artificial mask-ventilation in a randomised crossover design. A total of ten cycles of CPR were analysed. Results: Of the divers, 17 were able to ventilate with the modified LAR V. The median tidal volumes were lower with LAR V versus Ambu® (725 vs 800 ml; P=0.04) and median total time required was significantly longer with LAR V versus Ambu® (90 vs 68.5 s; P=0.004). Gastric inflation was associated only with the Ambu®. Conclusions: This modification of the LAR V makes it suitable for CPR performed by military divers when conventional ventilatory devices are not available. It would be necessary, however, to teach the proper use of the modified ventilation mode and to provide repeated training.

The study of the effectiveness of chest compressions using the CPR-plus

Effective cardiopulmonary resuscitation (CPR) requires a high level of skill from both healthcare professionals and the lay public. Inadequate chest compressions are a common cause of ineffective CPR. The CPR-plus is a non-invasive, hand-held, simple to use CPR adjunct designed to assist the rescuer to monitor and modify the compression technique during CPR, hopefully resulting in improved rescuer performance and more effective CPR. Forty qualified nurses were evaluated while they performed chest compressions on a training manikin. During simulated two-rescuer CPR (compression/ventilation ratio 5:1), the participants performed 150 compressions at a rate of 80–100/min. Compressions were performed with and without the CPR-plus and the results compared. The use of the CPR-plus was randomised with regard to whether the adjunct or the standard method was used first. The average number of correctly applied compressions was significantly better when the CPR-plus was used: 138.35/150 versus 110.70/150 ( p=0.0001). Improvements in techniques associated with the use of the CPR-plus also included a reduction in excessive application of pressure and incorrect hand position. The device provided reassurance of satisfactory compressions and an indication of impending fatigue in the rescuer.

The composition of gas given by mouth-to-mouth ventilation during CPR: Chest 1994; 106/6: 1806–1810

Study objective: To compare the concentration of a rescuer's exhaled O 2 and CO 2 during mouth-to-mouth ventilation with or without chest compression. Design: Prospective repeated measures study. Simulated one- and two-rescuer cardiopulmonary resuscitation (CPR) was performed as recommended by the American Heart Association. Setting: University laboratory. Participants: Fifty-five healthcare professionals certified in basic and advanced cardiac life support volunteered as rescuers in this study. Measurements and Results: Thirty-three volunteers performed one-rescuer CPR, and 22 volunteers performed two-rescuer CPR. Minute ventilation for both groups increased 50% to 130% during CPR (p<0.05). During the performance of CPR, the concentration of exhaled O 2 increased from 16.4±0.7% to 16.9±0.5% in the one-rescuer CPR group and from 16.5±0.9% to 17.8±0.6% in the two-rescuer CPR group (p<0.05). The concentration of exhaled CO 2 in the one-rescuer CPR group did not change significantly throughout the entire experiment, but decreased in the two-rescuer CPR group from a baseline measurement of 4.0±0.6% to 3.5±0.4% (p<0.05). DURING CPR, THE CONCENTRATION OF EXHALED CO 2 was 4.0±0.4% in the one-rescuer CPR group compared with 3.5±0.4% in the two-rescuer CPR group (p<0.05). Conclusion: The gas given by mouth-to-mouth ventilation is a bypercarbic and hypoxic mixture compared with room air. Mouth-to-mouth ventilation is the only circumstance in which a hypercarbic and hypoxic gas is given as therapy. Further laboratory and clinical studies are necessary to determine the effect of mouth-to-mouth ventilation during CPR

The Composition of Gas Given by Mouth-to-Mouth Ventilation During CPR

To compare the concentration of a rescuer's exhaled O2 and CO2 during mouth-to-mouth ventilation with or without chest compression. Prospective repeated measures study. Simulated one- and two-rescuer cardiopulmonary resuscitation (CPR) was performed as recommended by the American Heart Association. University laboratory. Fifty-five healthcare professionals certified in basic and advanced cardiac life support volunteered as rescuers in this study. Thirty-three volunteers performed one-rescuer CPR, and 22 volunteers performed two-rescuer CPR. Minute ventilation for both groups increased 50% to 130% during CPR (p < 0.05). During the performance of CPR, the concentration of exhaled O2 increased from 16.4 +/- 0.7% to 16.9 +/- 0.5% in the one-rescuer CPR group and from 16.5 +/- 0.9% to 17.8 +/- 0.6% in the two-rescuer CPR group (p < 0.05). The concentration of exhaled CO2 in the one-rescuer CPR group did not change significantly throughout the entire experiment, but decreased in the two-rescuer CPR group from a baseline measurement of 4.0 +/- 0.6% to 3.5 +/- 0.4% (p < 0.05). During CPR, the concentration of exhaled CO2 was 4.0 +/- 0.4% in the one-rescuer CPR group compared with 3.5 +/- 0.4% in the two-rescuer CPR group (p < 0.05). The gas given by mouth-to-mouth ventilation is a hypercarbic and hypoxic mixture compared with room air. Mouth-to-mouth ventilation is the only circumstance in which a hypercarbic and hypoxic gas is given as therapy. Further laboratory and clinical studies are necessary to determine the effect of mouth-to-mouth ventilation during CPR.