Single Rescuer Research Articles

Effect of metronome guidance on infant cardiopulmonary resuscitation.

This study was conducted to investigate the effect of metronome guidance on the performance of infant cardiopulmonary resuscitation (CPR). A total of 36 medical doctors conducted a 2-min single rescuer CPR with the two-finger technique (TFT) or two-thumb encircling hands technique (TT) on an infant manikin without metronome guidance (baseline test). After completing the baseline test, the participants were assigned to either a "guidance group" or "non-guidance group." The guidance group performed CPR with a high-pitched sound at 110 beats/min from a metronome (test 2), while the non-guidance group performed 2-min CPR without metronome guidance (test 1). Comparison between the results of tests 1 and 2 showed that the ratio of adequate chest compression rate was significantly different in both the TFT (73% [34-93] vs. 98% [95-99], P < 0.001) and the TT (53% [32-79] vs. 99% [98-100], P = 0.010). Other parameters including average depth and the ratio of adequate depth were not significantly different between tests 1 and 2 in both the TFT and TT.Conclusion: Metronome guidance improves the adequacy of chest compression rate during infant CPR without affecting chest compression depth in both the TFT and TT.Trial registration: Clinical Research Information Service, KCT0002735 What is Known: • The rate of chest compressions can be optimized by the use of metronome guidance in pediatric cardiopulmonary resuscitation (CPR). • An adverse effect of deteriorating chest compression depth was found while using a metronome guidance during adult CPR simulations. What is New: • The metronome guidance improved the adequacy of the chest compression rate during infant CPR without affecting other parameters including average depth and the ratio of adequate depth in both the two-finger chest compression technique and two-thumb encircling hand technique.

Availability and Use of an Automated External Defibrillator at Emergency Medical Dispatch

Objective: The aim of this study was to determine the frequency of automatic external defibrillator (AED) retrieval and placement by bystander callers when prompted by an Emergency Medical Dispatcher (EMD). Methods: This retrospective descriptive study utilized a convenience sample of emergency dispatch data collected from 23 Emergency Communication Centers (ECCs) spanning 14 states across the United States (U.S.) from July 11, 2014 to August 13, 2018, including all cases in which the EMD recorded any response to the AED availability prompt. Data were collected using ProQA, the software version of the Medical Priority Dispatch System. Primary outcome measures were (a) distribution of responses to the AED prompt; (b) percentage of cases in which an AED was retrieved; and (c) percentage of cases in which AED pads were placed by the bystander-caller. Results: A total of 2,200,285 cases were collected during the study period, in 18,904 (0.86%) of which the AED prompt was displayed (indicating suspected out of hospital cardiac arrest, or OHCA). Overall, an AED was reported as available 5.8% (n = 1,091) of the time the EMD recorded an answer to the AED prompt. In multiple-rescuer situations, a rescuer was sent to get the AED 2.8% (n = 523) of the time, as opposed to only 0.30% (n = 56) for single-rescuer calls. The AED was reported to be already on scene, by the patient, in 2.7% (n = 512) of the cases. A majority (72.0%; n = 417) of the time, rescuers who were sent to get an AED were unable to retrieve it, with single rescuers being successful more often (57.1% unable to retrieve, vs 73.6% for multiple rescuers). Conclusions: AEDs are reported as available by only a small percentage of callers to 911, and in the majority of cases in which a bystander rescuer is sent to retrieve an AED, one is never located or used. Sending someone to retrieve the AED may be more appropriate in multiple-rescuer situations than when a single bystander rescuer is alone on scene.

Practice of cardiopulmonary resuscitation among health care providers in a tertiary health centre in a semi-urban setting

Objectives: To assess the basic knowledge of cardiopulmonary resuscitation (CPR) among health workers in a tertiary health facility in a semi-rural county. Methods: A questionnaire based, cross sectional study involving health care professionals was performed in Federal Medical Centre, Birnin Kudu, Jigawa State, Nigeria from April to July 2017. A purposive sampling method was adopted for subject selection. A pretested self-administered questionnaire was distributed; this included knowledge on basic life support; participation in basic life supportand outcomes. It was adopted from the American Heart Association guidelines for CPR and emergency cardiac care. Results: One hundred and two respondents were recruited (40 doctors and 62 nurses). There were 50 males (49%) and 52 females (51%). Their age ranged from 23 to 54 years with mean of (34.9± 7.4) years. Only 20% of the respondents were aware of circulation, airway and circulation in adult resuscitation; however, 61.0% of all respondents were aware of airway, breathing and circulation of resuscitation in children. Furthermore, only 10% of the respondents were aware of the correct steps of single rescuer resuscitation. Their knowledge was poor about chest compression and ventilation for both adult and children resuscitation. The overall knowledge score ranged from 0.0% to 100% with mean knowledge score of (21.2±18.6)%. The date of last training about CPR had no relationship with the knowledge scores (χ2=2.951, P=0.300). The cadre of the respondents (doctors and nurses) had no relationship with their knowledge score (χ2=0.100, P=0.633 for doctors and nurses; ,χ2=7.074, P=0.225 for doctors cadre; XX2=3.868, P=0.677 for nurses cadre) respectively. Conclusions: The knowledge about CPR among health workers is poor; furthermore, the last date of training about CPR and the cadre of staffs have no relationship with knowledge of CPR.

Smartwatch feedback device for high-quality chest compressions by a single rescuer during infant cardiac arrest: a randomized, controlled simulation study.

ObjectiveAccording to the guidelines, rescuers should provide chest compressions (CC) ~1.5 inches (40 mm) for infants. Feedback devices could help rescuers perform CC with adequate rates (CCR) and depths (CCD). However, there is no CC feedback device for infant cardiopulmonary resuscitation (CPR). We suggest a smartwatch-based CC feedback application for infant CPR.Participants and methodsWe created a smartwatch-based CC feedback application. This application provides feedback on CCD and CCR by colour and text for infant CPR. To evaluate the application, 30 participants were divided randomly into two groups on the basis of whether CC was performed with or without the assistance of the smartwatch application. Both groups performed continuous CC-only CPR for 2 min on an infant mannequin placed on a firm table. We collected CC parameters from the mannequin, including the proportion of correct depth, CCR, CCD and the proportion of correct decompression depth.ResultsDemographics between the two groups were not significantly different. The median (interquartile range) proportion of correct depth was 99 (97–100) with feedback compared with 83 (58–97) without feedback (P = 0.002). The CCR and proportion of correct decompression depth were not significantly different between the two groups (P = 0.482 and 0.089). The CCD of the feedback group was significantly deeper than that of the control group [feedback vs. control: 41.2 (39.8–41.7) mm vs. 38.6 (36.1–39.6) mm; P=0.004].ConclusionRescuers who receive feedback of CC parameters from a smartwatch could perform adequate CC during infant CPR.

Cardiopulmonary Resuscitation Performance may Improve with Consideration of Performer’s Characteristics

Background: In basic life support, chest compressions are a very important and basic skill. Acquiring the ability to perform chest compressions is affected by individual characteristics such as physique and physical strength, although all persons can learn to Perform Cardiopulmonary Resuscitation (CPR), including chest compressions. The aim of this study was to examine differences in physique between males and females and Basic Life Support (BLS) skill using a portable manikin with automated corrective feedback.Methods: Participants were 120 fourth-year preclinical dental school students (87 males, 33 females). For skill assessment, students performed chest compressions and single rescuer CPR using a Laerdal Resusci Anne Skill Reporter TM manikin for 2 minutes each before and after CPR. Outcome measures were (1) compression depth (mm), (2) compression rate (number of compressions per minute), (3) compression release depth (recoil, mm), and (4) hand position before and after the BLS course.Results: After the BLS course, compression depth and rate improved significantly. Both before and after the BLS course, male students performed deeper chest compressions than female students. In females, the duration of acceptable chest compressions was significantly shorter than in males.Conclusion: CPR performance was significantly different between males and females, probably due to differences in physique. Therefore, it is necessary for individualized instruction adapted to the learner’s characteristics.

Why should we switch chest compression providers every 2 minutes during cardiopulmonary resuscitation?

Objective. This study was conducted to determine whether trained male rescuers could maintain adequate chest compres-sion depth (CCD) for longer than the cur-rent recommended guidelines of 2 minutes. Methods. Forty male medical doctors ad-ministered a 5-minute single rescuer car-diopulmonary resuscitation (CPR) to a manikin on the floor with conventional CPR or randomly administered continu-ous chest compressions (CCC). The ratio of compression to ventilation was set to 30:2 with mouth-to-mouth technique dur-ing conventional CPR. Chest compression data were recorded with an accelerometer device and divided into 1-minute segments for analysis.Results. Although average CCD main-tained the recommended depths through-out 5 minutes in conventional CPR, it de-creased significantly with CCC (1 minute: 55.4 ± 4.5 mm; 2 minutes: 54.2 ± 5.4 mm; 3 minutes: 52.6 ± 5.6 mm; 4 minutes: 51.6 ± 5.5 mm; 5 minutes: 49.9 ± 5.8 mm, p < 0.001). The average chest compression numbers (ACCN) per minute were main-tained over 80/min and have not been changed significantly within 5 minutes in the CCC. However, it didn’t reach to the 80/min and decreased significantly after 3minutes compared to the baseline ACCN during first 1-minute segment in the con-ventional CPR.Conclusions. Despite the chest compres-sion providers being limited to trained male medical doctors, the average CCD decreased significantly within 5minutes with CCC. Although maintaining adequate CCD, ACCN in each minute decreased sig-nificantly after 3minutes in the conventional CPR. Therefore, we should rotate chest compression providers every 2minutes re-gardless of the rescuer’s qualifications and CPR methods.

Chest compression on CPR and active abdominal on CPR

Chest compression cannot be effectively applied under certain situations, such as chest wall deformity, rib fracture, or hemopneumothorax. Active abdominal compression-decompression cardiopulmonary resuscitation (AACD-CPR) could reach better resuscitation outcomes in certain cardiac arrest (CA) patients. AACD-CPR can strengthen the high quality of cardiopulmonary resuscitation (CPR) in "2015 American Heart Association for cardiopulmonary resuscitation and emergency cardiovascular care update guide". The two methods can complement each other in opposite direction, and implement the "2016 national consensus on cardiopulmonary resuscitation on CPR in China", which is an important part of the wisdom to the Chinese CPR. In the article, we compared chest compression in standard single rescuer cardiopulmonary resuscitation (STD-CPR) and AACD-CPR with their aspects of the cause, mechanism, methods and application. We will provide an important reference about techniques of STD-CPR and AACD-CPR.

Skills among young and elderly laypersons during simulated dispatcher assisted CPR and after CPR training.

Dispatcher assisted cardiopulmonary resuscitation (DA-CPR) increase the rate of bystander CPR. The aim of the study was to compare the performance of DA-CPR and attainable skills following CPR training between young and elderly laypersons. Volunteer laypersons (young: 18-40 years; elderly: > 65 years) participated. Single rescuer CPR was performed in a simulated DA-CPR cardiac arrest scenario and after CPR training. Data were obtained from a manikin and from video recordings. The primary endpoint was chest compression depth. Overall, 56 young (median age: 26, years since last CPR training: 6) and 58 elderly (median age: 72, years since last CPR training: 26.5) participated. Young laypersons performed deeper (mean (SD): 56 (14) mm vs. 39 (19) mm, P < 0.001) and faster (median (25th-75th percentile): 107 (97-112) per min vs. 84 (74-107) per min, P < 0.001) chest compressions compared to elderly. Young laypersons had shorter time to first compression (mean (SD): 71 (11) seconds vs. 104 (38) seconds, P < 0.001) and less hands-off time (median (25th-75th percentile): 0 (0-1) seconds vs. 5 (2-10) seconds, P < 0.001) than elderly. After CPR training chest compressions were performed with a depth (mean (SD): 64 (8) mm vs. 50 (14) mm, P < 0.001) and rate (mean (SD): 111 (11) per min vs. 93 (18) per min, P < 0.001) for young and elderly laypersons respectively. Despite long CPR retention time for both groups, elderly laypersons had longer retention time, and performed inadequate DA-CPR compared to young laypersons. Following CPR training the attainable CPR level was of acceptable quality for both young and elderly laypersons.

“Knocking-fingers” chest compression technique in infant cardiac arrest: Single rescuer manikin study

Purpose: We designed a new chest compression technique, the “knocking-fingers” chest compression (KF) technique, for a single rescuer in infant cardiac arrest. We compared the effectiveness and feasibility between the KF technique and the two-finger (TF) and two-thumb encircling (TT) techniques.

Method of chest compression for infants in a single rescuer: Evaluation of chest compression technique and new device

Background: The American Heart Association (AHA) recommends the 2-finger technique (TFT) for a lone rescuer and the 2-thumb-encircling hands (TTHT) technique for two rescuers. During cardiopulmonary resuscitation (CPR), high quality chest compression is the most important factor. However, chest compressions during pediatric CPR are often suboptimal.

Single Rescuer Ventilation Using a Bag Valve Mask with Removable External Handle: A Randomized Crossover Trial.

This study was a randomized crossover trial of adult health care providers performing ventilation on a manikin. Investigators randomized participants to perform single rescuer ventilation, first using either a BVM modified by addition of a supplemental external handle or a standard unmodified BVM (Spur II BVM device; Ambu; Ballerup, Denmark). Participants performed mask placement and delivery of 10 breaths per minute for three minutes, as guided by a metronome. After a three-minute rest period, they performed ventilation using the alternative device. The primary outcome measure was mean received tidal volume as measured by the manikin (IngMar RespiTrainer model; IngMar Medical; Pittsburgh, Pennsylvania USA). Secondary outcomes included subject device preference. Of 70 recruited participants, all completed the study. The difference in mean received tidal volume between ventilations performed using the modified BVM with external handle versus standard BVM was 20 ml (95% CI, -16 to 56 ml; P=.28). There were no significant differences in mean received tidal volume based on the order of study arm allocation. The proportion of participants preferring the modified BVM over the standard BVM was 47.1% (95% CI, 35.7 to 58.6%). The modified BVM with added external handle did not result in greater mean received tidal volume compared to standard BVM during single rescuer ventilation in a manikin model. Reed P , Zobrist B , Casmaer M , Schauer SG , Kester N , April MD . Single rescuer ventilation using a bag valve mask with removable external handle: a randomized crossover trial. Prehosp Disaster Med. 2017;32(6):625-630.

PERFORMANCE OF CHEST COMPRESSIONS WITH THE USE OF THE NEW MECHANICAL CHEST COMPRESSION MACHINE LIFELINE ARM: A RANDOMIZED CROSSOVER MANIKIN STUDY IN NOVICE PHYSICIANS

BACKGROUND: The Lifeline ARM (ARM; De btech, Guilford, USA) is a new mechanical chest compression device. The aim of the current study was to compare the quality of single rescuer cardiopulmonary resuscitation (CPR) with and without ARM device. METHODS: In this randomized crossover manikin trial forty-four novice physicians participated. Thirty minutes of training was allotted for manual CPR and then for the ARM. The following day, every participant performed a 2-min CPR single rescuer scenario, once with manual CPR and once with the ARM. The primary outcome measure of the study is effective compression; de ned as compressions performed with the correct of depth of 50–60 mm, complete decompressions, and the correct pressure point of CC. RESULTS: The ARM, compared with manual CPR, carried out more effective compressions (96 [interquartile range, IQR; 94–98] vs. 36 [IQR; 33–41]%, p &lt; 0.001). The compressions preformed with the use of the ARM, furthermore, were with a correct CC rate (100 [IQR; 99–101] vs. 130 [IQR; 124–140] min -1 ; p&lt;0.001) and a correct depth (97 [IQR; 96–98] vs. 37 [IQR; 31–39]%; p&lt;0.001). The result of resuscitation with ARM was signi cantly better than manual CPR (p&lt;0.05) for all of the analyzed chest compression parameters (percentage of CC too deep, percentage of CC too shallow, percentage of correct pressure points and percentage of correct pressure releases), as well as for the ventilation parameters (tidal volume, ventilation rate, minute-volume, gastric in ations). CONCLUSION: During this simulated trial, when CPR was performed by novice physicians, the ARM signi cantly improved the quality of CPR. Further clinical trials should provide motivation to con rm the potential bene ts of ARM use during CPR.

Time delays to reach dispatch centres in different regions in Europe. Are we losing the window of opportunity? — The EUROCALL study

AimIn out of hospital cardiac arrest (OHCA) the start of Cardiopulmonary Resuscitation (CPR) by a single rescuer may be delayed considerably if the total time (TT) to connect the telephone call to the Emergency Medical Communication Centre (EMCC) is prolonged. EUROCALL investigated the TT-EMCC and its components using different calling procedures. MethodsThis prospective, multicentre, randomised study was performed in April 2013. Telephone calls were randomly allocated to time of call, and to those connecting directly to the EMCC (1-step procedure) and those diverted before connecting to the EMCC (2-step procedure). ResultsTwenty-one EMCCs from 11 countries participated in the study. Time to first ringtone was similar between 1-step 3.7s (IQR 1.0–5.2) and 2-step calls 4.0s (IQR 2.4–5.2). For the 1878 1-step calls, the median TT-EMCC was 11.7s (IQR 8.7–18.5). For the 1550 2-step calls, the median time from first ringtone to first call-taker was 7s (IQR 4.6–11.9) and from first call-taker to EMCC was 18.7s (IQR 13.4–29.9). Median TT-EMCC was 33.2 s (IQR 24.7–46.1) and was significantly longer than the TT-EMCC observed with the 1-step procedure (P<0.0001). Significant differences existed among participating regions between and within different countries both for 1-step and 2-step procedures. ConclusionTT-EMCC was significantly shorter in a 1-step procedure compared to a 2-step procedure. Regional differences existed between countries but also within countries. This may be relevant in cases of OHCA and other situations where patient outcome is critically time-dependent.

Keep pushing! Limiting interruptions to CPR; bag-valve mask versus i-gel® airway ventilation

Background: Recent recommendations made by ILCOR have de-emphasised the role of advanced airway management such as “endotracheal intubation” (ETI) during cardiac arrest in favour of maximising the number of chest compressions performed by rescuers. Maximising time available for compressions is achieved by minimising hands-off time (HOT). This has led to first responders and paramedics performing single rescuer CPR using a bag-valve-mask (BVM) device as opposed to the historical practice of intubating and ventilating via an endotracheal tube. Bag-valve-mask ventilations, especially during single rescuer CPR, are however associated with complications potentially resulting in increased ventilation times. More time spent on ventilations in the single rescuer scenario naturally leads to an increase in HOT and less time being available for compressions. It is postulated that the use of an appropriate supraglottic airway device (SAD) may decrease the time spent on the ventilation component of CPR and result in a decrease in HOT.Objectives: This pilot study evaluated how interruptions to chest compressions or hands-off time (HOT) are affected by the placement of an i-gel® airway vs. simple BVM ventilation during single rescuer CPR.Method: 16 participants performed two, ten-minute single rescuer CPR simulations, firstly using the BVM and later the i-gel® airway for ventilation. Data pertaining to ventilations and HOT in each scenario was statistically analysed and compared.Results: The i-gel® airway demonstrated a superior ease of ventilation compared to BVM alone and resulted in a reduction of time spent on ventilations overall. The i-gel® however took a mean of 29 s, ± 10 s, to secure which contributes considerably to HOT.Conclusion: The use of the i-gel® airway resulted in a considerable decrease in the amount of time spent on ventilations and in more compressions being performed. The overall reduction in HOT was, however, offset by the time it took to secure the device. Further investigation into the use and securing of the i-gel® airway in single rescuer CPR is recommended.

285 New Chest Compression Method in Infant Resuscitations

For infants, cardiopulmonary resuscitation (CPR) guidelines recommend two-finger (2F) chest compression with a single rescuer and two-thumb encircling (2T) method with two rescuer. Two-thumb makes better chest compression compared with two-finger method but is increased ventilation hands-off time. To overcome the disadvantages of these two methods, we created the new method, cross-thumb (CT) compression. We investigated whether the cross-thumb compression is effective compared with two standard methods of the 2F and the 2T. Fifty-seven emergency and pediatric residents were randomly assigned into three groups. Participants were already trained pediatric basic life support programs. They performed 2 minutes of lone rescuer 30:2 compression:ventilation CPR using LaerdalTM manikin (Resusci® Baby QCPR) and answered a short questionnaire about difficulty level, fatigue strength and pain of hands using a numeric rating scales (NRS) from 1 to 10 at the end of study. The parameters of CPR were recorded by Resusci® Baby QCPR. Differences of CPR parameters between groups were assessed using the analysis of vairance (Kruskal-Wallis test) and a p-value below 0.05 was considered as statistically significance. Post-test was performed after correcting by Bonferroni correction. The mean rates of chest compression per a minute were not different among the groups, with 109.4 ± 6.1 in 2F, 110.8 ± 9.9 in 2T and 110.9 ± 8.2. The depth of compression in 2T was extremely shallower compared with other two methods (39.0 ± 2.7 mm in 2F, 42.2 ± 1.0 mm in 2T and 42.3 ± 2.9 mm in CT, p=0.00). After the post-hoc analysis, 2T and CT method could compress deeper than 2F and there were no statistically difference between 2T and CT. The mean percentage of accurate location of chest compression during 5 cycles CPR showed higher in CT, 94.6 ± 13.0% (84.0 ± 30.5% in 2F and 86.7 ± 28.1% in 2T) but the result had no significance (p=0.81). Statistically significant differences in the mean of hands-off time were observed (p=0.01). The time was shorter in 2F method (5.9 ± 1.2 sec) than others. No difference was between 2T and CT (7.5 ± 2.1 sec, 7.0 ± 1.3 sec, respectively). The difficulty level of compression methods were not different. Participants answered more tired and painful with 2F (p=0.00, p=0.00 respectively). The mean of NRS for fatigue strength were 6.9 in 2F, 4.6 in 2T and 4.0 in CT. The mean of NRS for pain of hands were 7.2 in 2F, 4.3 in 2T and 4.4 in CT. But there were no difference of fatigue and pain between 2T and CT. 2T and CT methods can compress stronger and also less tiring and less painful compared with 2F method. CT showed a trend of correct hand position upon chest wall compared with other two method. Although hand-off time was slightly longer during 2T and CT than 2F, the gap of time was not problematic rather than other studies. CT compression might consider a new method for a lone rescuer in infant CPR.

Single rescuer ventilation using a bag-valve mask with internal handle: a randomized crossover trial

ObjectiveTo compare tidal volume received during single rescuer ventilation with a modified bag-valve mask (BVM) with integrated internal handle vs standard BVM among healthy volunteers using a manikin model. MethodsThis study was a randomized crossover trial of adult healthcare provider volunteers performing ventilation on a manikin. We randomized participants to perform single rescuer ventilation first using either a modified BVM with integrated internal handle or a standard unmodified BVM. Participants were responsible for mask placement and delivery of 10 breaths per minute for 3 minutes as guided by a metronome. After a 3-minute rest period, they performed ventilation using the alternative device. The primary outcome measure was mean received tidal volume as measured by the manikin (IngMar RespiTrainer model). Secondary outcomes included participant reported device preference. ResultsOf 70 recruited participants, all completed the study. Mean received tidal volume was higher using the modified BVM with integrated internal handle vs standard BVM by 90 mL (95% confidence interval, 60-120 mL; P< .0001). There were no significant differences in mean received tidal volume based on the order of study arm allocation. Eighty percent of participants reported preference for the modified BVM over the standard BVM (95% confidence interval, 70.0%-80.0%). ConclusionsThe modified BVM with integrated internal handle results in greater mean received tidal volume compared with standard BVM during single rescuer ventilation in a manikin model. This modified BVM design may prove a useful airway adjunct for ventilation.

백밸브마스크를 이용한 1인 심폐소생술에서 구조자 위치 변화에 따른 가슴압박과 인공호흡의 질 변화 연구

백밸브마스크를 이용한 1인 심폐소생술에서 구조자 위치 변화에 따른 가슴압박과 인공호흡의 질 변화 연구

Keep pushing! Limiting interruptions to CPR; bag-valve mask versus i-gel® airway ventilation

BackgroundRecent recommendations made by ILCOR have de-emphasised the role of advanced airway management such as “endotracheal intubation” (ETI) during cardiac arrest in favour of maximising the number of chest compressions performed by rescuers. Maximising time available for compressions is achieved by minimising hands-off time (HOT). This has led to first responders and paramedics performing single rescuer CPR using a bag-valve-mask (BVM) device as opposed to the historical practice of intubating and ventilating via an endotracheal tube. Bag-valve-mask ventilations, especially during single rescuer CPR, are however associated with complications potentially resulting in increased ventilation times. More time spent on ventilations in the single rescuer scenario naturally leads to an increase in HOT and less time being available for compressions. It is postulated that the use of an appropriate supraglottic airway device (SAD) may decrease the time spent on the ventilation component of CPR and result in a decrease in HOT. ObjectivesThis pilot study evaluated how interruptions to chest compressions or hands-off time (HOT) are affected by the placement of an i-gel® airway vs. simple BVM ventilation during single rescuer CPR. Method16 participants performed two, ten-minute single rescuer CPR simulations, firstly using the BVM and later the i-gel® airway for ventilation. Data pertaining to ventilations and HOT in each scenario was statistically analysed and compared. ResultsThe i-gel® airway demonstrated a superior ease of ventilation compared to BVM alone and resulted in a reduction of time spent on ventilations overall. The i-gel® however took a mean of 29 s, ± 10 s, to secure which contributes considerably to HOT. ConclusionThe use of the i-gel® airway resulted in a considerable decrease in the amount of time spent on ventilations and in more compressions being performed. The overall reduction in HOT was, however, offset by the time it took to secure the device. Further investigation into the use and securing of the i-gel® airway in single rescuer CPR is recommended.

Comparison of Fatigue During Cardiocerebral Resuscitation with Different Compression Rates Among Layperson and Professional Rescuers

Nearly 383,000 out-of-hospital sudden cardiac arrests occur annually in the United States, with 88 percent occurring at home. Cardiopulmonary resuscitation continues to evolve and emphasizes higher frequency chest compressions, ≥ 100 compressions per min (cpm), and “hands-only” cardiocerebral resuscitation (CCR), particularly for lay rescuers. Greater compression frequency may accelerate rescuer fatigue and limit the time a single rescuer may provide circulation. PURPOSE: To quantify the differences in heart rate, RPE and time to fatigue at 80 cpm vs. 100 cpm in solo rescuers, and to determine if aerobic fitness and chest strength/endurance were predictive of the ability to sustain CCR. METHODS: Sixty-one subjects, 20 men aged 20-56 yrs and 41 women aged 20-45 yrs performed two trials of uninterrupted chest compressions on a manikin for up to 15 min per trial. Each subject performed, in random order, one trial at 80 cpm and another trial at 100 cpm with at least 5 min rest between trials. The manikin provided continuous biofeedback regarding rate and depth of compressions. Relative cardiorespiratory fitness and chest strength/endurance were estimated via YMCA step and bench press tests. Logistic regression was used to identify predictors of the ability to sustain compressions for 15 min. RESULTS: There were no significant differences (p>0.05) in mean HR (125.6 vs. 129.0 bpm), RPE (5.2 vs. 5.9), or trial duration (11:22 vs. 11:07 min) between the 80 cpm and 100 cpm trials. Professional rescuers were more likely to complete the 15 min 100 cpm trial than lay rescuers (p=.0346), and men were more likely than women (p=.0068). High relative chest strength/endurance was a significant predictor of completion of the 100 cpm trial (p=0.0188), but relative cardiorespiratory fitness was not. Wrist pain, muscular fatigue, and shoulder pain were the leading reasons for terminating compressions before the 15 min trial end point. CONCLUSIONS: Chest, shoulder and arm muscular strength and endurance are more important determinants of fatigue than cardiorespiratory fitness when performing CCR. Persons likely to perform CCR should develop and maintain chest, shoulder and arm muscle strength and endurance. Lay and women solo rescuers should consider lower compression frequencies during CCR when relief will be delayed.

Performance of cardiopulmonary resuscitation during prolonged basic life support in military medical university students: A manikin study.

The quality of chest compressions can be significantly improved after training of rescuers according to the latest national guidelines of China. However, rescuers may be unable to maintain adequate compression or ventilation throughout a response of average emergency medical services because of increased rescuer fatigue. In the present study, we evaluated the performance of cardiopulmonary resuscitation (CPR) in training of military medical university students during a prolonged basic life support (BLS). A 3-hour BLS training was given to 120 military medical university students. Six months after the training, 115 students performed single rescuer BLS on a manikin for 8 minutes. The qualities of chest compressions as well as ventilations were assessed. The average compression depth and rate were 53.7±5.3 mm and 135.1±15.7 compressions per minute respectively. The proportion of chest compressions with appropriate depth was 71.7%±28.4%. The average ventilation volume was 847.2±260.4 mL and the proportion of students with adequate ventilation was 63.5%. Compared with male students, significantly lower compression depth (46.7±4.8 vs. 54.6±4.8 mm, P<0.001) and adequate compression rate (35.5%±26.5% vs. 76.1%±25.1%, P<0.001) were observed in female students. CPR was found to be related to gender, body weight, and body mass index of students in this study. The quality of chest compressions was well maintained in male students during 8 minutes of conventional CPR but declined rapidly in female students after 2 minutes according to the latest national guidelines. Physical fitness and rescuer fatigue did not affect the quality of ventilation.