Deeper chest compression – More complications for cardiac arrest patients?

Aim of the study

Sternal and rib fractures are frequent complications caused by chest compressions during cardiopulmonary resuscitation (CPR). This study aimed to investigate the potential association of CPR-related thoracic and abdominal injuries and compression depth measured with an accelerometer.

Methods

We analysed the autopsy records, CT scans or chest radiographs of 170 adult patients, suffering in-hospital cardiac arrest at the Tampere University Hospital during the period 2009–2011 to investigate possible association of chest compressions and iatrogenic injuries. The quality of manual compressions during CPR was recorded on a Philips, HeartStart MRx Q-CPR™-defibrillator.

Results

Patients were 110 males and 60 females. Injuries were found in 36% of male and 23% of female patients. Among male patients CPR-related injuries were associated with deeper mean – and peak compression depths (p < 0.05). No such association was observed in women. The frequency of injuries in mean compression depth categories <5, 5–6 and >6 cm, was 28%, 27% and 49% (p = 0.06). Of all patients 27% sustained rib fractures, 11% sternal fracture and eight patients had haematomas/ruptures in the myocardium. In addition, we observed one laceration of the stomach without bleeding, one ruptured spleen, one mediastinal haemorrhage and two pneumothoraxes.

Conclusion

The number of iatrogenic injuries in male patients was associated with chest compressions during cardiopulmonary resuscitation increased as the measured compression depth exceeded 6 cm. While there is an increased risk of complications with deeper compressions it is important to realize that the injuries were by and large not fatal.     

Chest injury following cardiopulmonary resuscitation: A prospective computed tomography evaluation

Introduction

Traumatic chest injuries may occur following cardiopulmonary resuscitation (CPR). The aim of this study was to address the frequency of injuries, especially rib and sternal fractures, and also to identify factors that contribute to post-CPR trauma.

Methods

This study was a prospective cross-sectional study conducted in the emergency departments (ED) of eight academic tertiary care centers. To evaluate injuries secondary to CPR, we performed chest computed tomography (CT) in patients who were successfully resuscitated from cardiac arrest. Contributing factors that might be related to injuries were also investigated.

Results

We enrolled 71 patients between 1 January 2011 and 30 June 2011. Rib and sternal fractures were diagnosed in 22 and 3 patients, respectively. Females were more susceptible to rib fracture (p = 0.036). When non-physicians participated as chest compressors in the ED, more ribs were fractured (p = 0.048). The duration of CPR and number of compressors were not contributing factors to trauma secondary to CPR. There was a wide variation in the frequency of rib fractures from hospital to hospital (0–83.3%). In high-risk hospitals (in which more than 50% of patients had rib fractures), the average age of the patients was higher, and non-physicians took part in ED CPR more often than they did at low-risk hospitals.

Conclusion

The incidence of rib fracture following CPR was different in various hospitals. The presence of non-physician chest compressors in the ED was one of the contributing factors to rib fracture. Further studies on the influence of resuscitators and relation between quality of chest compression and CPR-induced injuries are warranted to reduce complications following CPR.     

A pilot study of mechanical chest compressions with the LUCAS™ device in cardiopulmonary resuscitation

Aim

The LUCAS™ device has been shown to improve organ perfusion during cardiac arrest in experimental studies. In this pilot study the aim was to compare short-term survival between cardiopulmonary resuscitation (CPR) performed with mechanical chest compressions using the LUCAS™ device and CPR performed with manual chest compressions. The intention was to use the results for power calculation in a larger randomised multicentre trial.

Methods

In a prospective pilot study, from February 1, 2005, to April 1, 2007, 149 patients with out-of hospital cardiac arrest in two Swedish cities were randomised to mechanical chest compressions or standard CPR with manual chest compressions.

Results

After exclusion, the LUCAS and the manual groups contained 75 and 73 patients, respectively. In the LUCAS and manual groups, spontaneous circulation with a palpable pulse returned in 30 and 23 patients (p = 0.30), spontaneous circulation with blood pressure above 80/50 mmHg remained for at least 5 min in 23 and 19 patients (p = 0.59), the number of patients hospitalised alive >4 h were 18 and 15 (p = 0.69), and the number discharged, alive 6 and 7 (p = 0.78), respectively.

Conclusions

In this pilot study of out-of-hospital cardiac arrest patients we found no difference in early survival between CPR performed with mechanical chest compression with the LUCAS™ device and CPR with manual chest compressions. Data have been used for power calculation in a forthcoming multicentre trial.     

3:1 Compression to ventilation ratio versus continuous chest compression with asynchronous ventilation in a porcine model of neonatal resuscitation

Objective

In contrast to the resuscitation guidelines of children and adults, guidelines on neonatal resuscitation recommend synchronized 90 chest compressions with 30 manual inflations (3:1) per minute in newborn infants. The study aimed to determine if chest compression with asynchronous ventilation improves the recovery of bradycardic asphyxiated newborn piglets compared to 3:1 Compression:Ventilation cardiopulmonary resuscitation (CPR).

Intervention and measurements

Term newborn piglets (n = 8/group) were anesthetized, intubated, instrumented and exposed to 45-min normocapnic hypoxia followed by asphyxia. Protocolized resuscitation was initiated when heart rate decreased to 25% of baseline. Piglets were randomized to receive resuscitation with either 3:1 compressions to ventilations (3:1 C:V CPR group) or chest compressions with asynchronous ventilations (CCaV) or sham. Continuous respiratory parameters (Respironics NM3^®), cardiac output, mean systemic and pulmonary artery pressures, and regional blood flows were measured.

Main results

Piglets in 3:1 C:V CPR and CCaV CPR groups had similar time to return of spontaneous circulation, survival rates, hemodynamic and respiratory parameters during CPR. The systemic and regional hemodynamic recovery in the subsequent 4 h was similar in both groups and significantly lower compared to sham-operated piglets.

Conclusion

Newborn piglets resuscitated by CCaV had similar return of spontaneous circulation, survival, and hemodynamic recovery compared to those piglets resuscitated by 3:1 Compression:Ventilation ratio.     

Performance of the i-gel™ during pre-hospital cardiopulmonary resuscitation

Background

Current cardiopulmonary resuscitation (CPR) guidelines recommend airway management and ventilation whilst minimising interruptions to chest compressions. We have assessed i-gel™ use during CPR.

Methods

In an observational study of i-gel™ use during CPR we assessed the ease of i-gel™ insertion, adequacy of ventilation, the presence of a leak during ventilation, and whether ventilation was possible without interrupting chest compressions.

Results

We analysed i-gel™ insertion by paramedics (n = 63) and emergency physicians (n = 7) in 70 pre-hospital CPR attempts. There was a 90% first attempt insertion success rate, 7% on the second attempt, and 3% on the third attempt. Insertion was reported as easy in 80% (n = 56), moderately difficult in 16% (n = 11), and difficult in 4% (n = 3). Providers reported no leak on ventilation in 80% (n = 56), a moderate leak in 17% (n = 12), and a major leak with no chest rise in 3% (n = 2). There was a significant association between ease of insertion and the quality of the seal (r = 0.99, p = 0.02). The i-gel™ enabled continuous chest compressions without pauses for ventilation in 74% (n = 52) of CPR attempts. There was no difference in the incidence of leaks on ventilation between patients having continuous chest compressions and patients who had pauses in chest compressions for ventilation (83% versus 72%, p = 0.33, 95% CI [−0.1282, 0.4037]). Ventilation during CPR was adequate during 96% of all CPR attempts.

Conclusions

The i-gel™ is an easy supraglottic airway device to insert and enables adequate ventilation during CPR.     

Quality of CPR performed by trained bystanders with optimized pre-arrival instructions

Objective

Telephone-CPR (T-CPR) can increase initiation of bystander CPR. We wanted to study if quality oriented continuous T-CPR would improve CPR performance vs. standard T-CPR.

Method

Ninety-five trained rescuers aged 22–69 were randomized to standard T-CPR or experimental continuous T-CPR (comprises continuous instructions, questions and encouragement). They were instructed to perform 10 min of chest compressions-only on a manikin, which recorded CPR performance in a small, confined kitchen. Three video-cameras captured algorithm time data, CPR technique and communication. Demography and training experience were captured during debriefing.

Results

Participants receiving continuous T-CPR delivered significantly more chest compressions (median 1000 vs. 870 compressions, p = 0.014) and compressed more frequently to a compression rate between 90 and 120 min⁻¹ (median 87% vs. 60% of compressions, p < 0.001), compared to those receiving standard T-CPR. This also resulted in less time without compressions after CPR had started (median 12 s vs. 64 s, p < 0.001), but longer time interval from initiating contact with dispatcher to first chest compression (median 144 s vs. 84 s, p < 0.001). There was no difference in chest compression depth (mean 47 mm vs. 48 mm, p = 0.90) or in demography, education and previous CPR training between the groups.

Conclusion

In our simulated scenario with CPR trained lay rescuers, experimental continuous T-CPR gave better chest compression rate and less hands-off time during CPR, but resulted in delayed time to first chest compression compared to standard T-CPR instructions.     

Real-time feedback can improve infant manikin cardiopulmonary resuscitation by up to 79%—A randomised controlled trial

Setting

European and Advanced Paediatric Life Support training courses.

Participants

Sixty-nine certified CPR providers.

Interventions

CPR providers were randomly allocated to a ‘no-feedback’ or ‘feedback’ group, performing two-thumb and two-finger chest compressions on a “physiological”, instrumented resuscitation manikin. Baseline data was recorded without feedback, before chest compressions were repeated with one group receiving feedback.

Main outcome measures

Indices were calculated that defined chest compression quality, based upon comparison of the chest wall displacement to the targets of four, internationally recommended parameters: chest compression depth, release force, chest compression rate and compression duty cycle.

Results

Baseline data were consistent with other studies, with <1% of chest compressions performed by providers simultaneously achieving the target of the four internationally recommended parameters. During the ‘experimental’ phase, 34 CPR providers benefitted from the provision of ‘real-time’ feedback which, on analysis, coincided with a statistical improvement in compression rate, depth and duty cycle quality across both compression techniques (all measures: p < 0.001). Feedback enabled providers to simultaneously achieve the four targets in 75% (two-finger) and 80% (two-thumb) of chest compressions.

Conclusions

Real-time feedback produced a dramatic increase in the quality of chest compression (i.e. from <1% to 75–80%). If these results transfer to a clinical scenario this technology could, for the first time, support providers in consistently performing accurate chest compressions during infant CPR and thus potentially improving clinical outcomes.     

Quality of chest compressions during continuous CPR; comparison between chest compression-only CPR and conventional CPR

Objectives

This study aimed to compare the time-dependent deterioration of chest compressions between chest compression-only cardiopulmonary resuscitation (CPR) and conventional CPR.

Methods

This study involved 106 and 107 participants randomly assigned to chest compression-only CPR training and conventional CPR training, respectively. Immediately after training, participants were asked to perform CPR for 2 min and the quality of their CPR skills were evaluated. The number of chest compressions in total and those with appropriate depth were counted every 20-s CPR period from the start of CPR. The primary outcome was the CPR quality index calculated as the proportion of chest compressions with appropriate depth among total chest compressions.

Results

The total number of chest compressions remained stable over time both in the chest compression-only and the conventional CPR groups. The CPR quality index, however, decreased from 86.6 ± 25.0 to 58.2 ± 36.9 in the chest compression-only CPR group from 0-20 s through 61-80 s. The reduction was greater than in the conventional CPR group (85.9 ± 25.5 to 74.3 ± 34.0). The difference in the CPR quality index reached statistical significance (p = 0.003) at 61-80 s period.

Conclusions

Chest compressions with appropriate depth decreased more rapidly during chest compression-only CPR than conventional CPR. We recommend that CPR providers change their roles every 1 min to maintain the quality of chest compressions during chest compression-only CPR. (UMIN-CTR C0000000321)     

Should dispatchers instruct lay bystanders to undress patients before performing CPR? A randomized simulation study

Objective

Dispatch-assisted CPR instructions frequently direct bystanders to remove a cardiac arrest patient's clothing prior to starting chest compressions. Removing clothing may delay compressions and it is uncertain whether CPR quality is influenced by the presence of clothing. We measured how instructions to remove clothing impacted the time to compressions and CPR performance by lay responders in a simulated arrest.

Subjects and methods

We conducted a randomized dispatch-assisted CPR simulation trial. Fifty two lay participants were instructed to remove the manikin's clothing (3 layers: a t-shirt, button-down shirt, and fleece vest) prior to starting chest compressions as part of dispatcher instructions, while 47 individuals received no instruction about clothing removal. Instructions were otherwise identical.

Results

The two groups were comparable with regard to demographic characteristics and prior CPR training. Time to first compression was 109 s among the group randomized to instruction to remove clothing and 79 s among those randomized to forgo instruction regarding clothing removal, (p < 0.001). Among those randomized to remove clothing instructions, mean compression depth was 41 mm, compression rate was 97 per minute, and the percentage with complete compression release was 95%. Among those randomized to forgo clothing removal instruction, mean compression depth was 40 mm, compression rate was 99 per minute, and the percentage with complete compression release was 91% (p > 0.05 for each CPR metric comparison).

Conclusion

These findings suggest that eliminating instruction to remove a victim's clothing in dispatcher-assisted CPR will save time without compromising performance, which may improve survival from cardiac arrest.     

The analysis of efficacy for AutoPulse™ system in flying helicopter

Aim of the study

The helicopter emergency medical service (HEMS) was introduced in Japan in 2001, and some cardiopulmonary arrest (CPA) patients are transported using this service. However, it is difficult to maintain continuous and effective manual cardiopulmonary resuscitation (CPR) in flying helicopters. To overcome this problem, the AutoPulse™ system, automated mechanical CPR devices, was induced. We conducted a retrospective study to clarify the efficacy of AutoPulse™ on CPA patients in flying helicopters.

Methods

In total, 92 CPA patients were enrolled in this study. Of these, 43 CPA patients received manual CPR (between April 2004 and June 2008), and 49 patients received AutoPulse™ CPR (between July 2008 and March 2011). We compared the manual CPR group with the AutoPulse™ group using logistic regression analysis and examined the efficacy of AutoPulse™ in flying helicopters.

Results

Rates for return of spontaneous circulation (ROSC) and survival to hospital discharge were increased in the AutoPulse™ group compared to the manual CPR group (ROSC, 30.6% [15 patients] vs. 7.0% [3 patients]; survival to hospital discharge, 6.1% [3 patients] vs. 2.3% [1 patient]). In multivariate analysis, the factors associated with ROSC were the use of AutoPulse™ (odds ratio [OR], 7.22; P = 0.005) and patients aged ≤65 years (OR, 0.31; P = 0.042).

Conclusion

The present study demonstrates that the use of AutoPulse™ in flying helicopters was significantly effective for the ROSC in CPA patients. The use of automated chest compression devices such as AutoPulse™ might be recommended at least for CPA patients transported by helicopters.     

A novel method to decrease mattress compression during CPR using a mattress compression cover and a vacuum pump

Background

Mattress compression causes feedback devices to over-estimate the chest compression depth measurement during CPR. We propose a novel method to decrease the mattress compression using a vinyl cover. This mattress compression cover encloses the foam mattress and is compressed by a vacuum pump immediately prior to performing CPR.

Methods

Nine CPR providers performed chest compressions on manikins placed on a conventional foam mattress on a bed frame (surface CONV), a backboard and foam mattress on a bed frame (surface BB), and a foam mattress, compressed with a vacuum pump, on a bed frame (surface VAC). Dual accelerometers were used to simultaneously measure the mattress compression and chest compression depths.

Results

The mattress compression depth levels decreased from 14.9 mm (SD 1.4 mm) on surface CONV to 7.0 mm (SD 0.6 mm) on surface VAC (p < 0.001) whereas 14.0 mm (SD 1.3 mm) on surface BB. The total compression depth was 65.4 mm (SD 3.8 mm) on surface CONV, and 58.3 mm (SD 3.0 mm) on surface VAC (p < 0.001).

Conclusion

Using a mattress compression cover and a vacuum pump appears to increase the rigidity of the mattress and allow for efficient chest compressions. This novel method could decrease the mattress compression depth and increase the efficiency of chest compression during CPR in hospitals.     

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.     

A randomised control trial of prompt and feedback devices and their impact on quality of chest compressions—A simulation study

Aim

This study aims to compare the effect of three CPR prompt and feedback devices on quality of chest compressions amongst healthcare providers.

Methods

A single blinded, randomised controlled trial compared a pressure sensor/metronome device (CPREzy™), an accelerometer device (Phillips Q-CPR) and simple metronome on the quality of chest compressions on a manikin by trained rescuers. The primary outcome was compression depth. Secondary outcomes were compression rate, proportion of chest compressions with inadequate depth, incomplete release and user satisfaction.

Results

The pressure sensor device improved compression depth (37.24–43.64 mm, p = 0.02), the accelerometer device decreased chest compression depth (37.38–33.19 mm, p = 0.04) whilst the metronome had no effect (39.88 mm vs 40.64 mm, p = 0.802). Compression rate fell with all devices (pressure sensor device 114.68–98.84 min⁻¹, p = 0.001, accelerometer 112.04–102.92 min⁻¹, p = 0.072 and metronome 108.24 min⁻¹ vs 99.36 min⁻¹, p = 0.009). The pressure sensor feedback device reduced the proportion of compressions with inadequate depth (0.52 vs 0.24, p = 0.013) whilst the accelerometer device and metronome did not have a statistically significant effect. Incomplete release of compressions was common, but unaffected by the CPR feedback devices. Users preferred the accelerometer and metronome devices over the pressure sensor device. A post hoc study showed that de-activating the voice prompt on the accelerometer device prevented the deterioration in compression quality seen in the main study.

Conclusion

CPR feedback devices vary in their ability to improve performance. In this study the pressure sensor device improved compression depth, whilst the accelerometer device reduced it and metronome had no effect.     

Comparison of computed tomography and autopsy in detection of injuries after unsuccessful cardiopulmonary resuscitation

Aim

Computed tomography (CT) has been suggested as an aid or even a replacement for autopsy. The aim of this trial was to study the conformity of the two methods in finding injuries in non-surviving patients after unsuccessful cardiopulmonary resuscitation.

Methods

In this prospective study, 31 patients were submitted to a CT prior to autopsy after unsuccessful resuscitation attempts. Pathological findings were noted by both the radiologist and the pathologists in a specified protocol. The pathologists and radiologist were blinded from each other's results.

Results

CT and autopsy revealed rib fractures in 22 and 24 patients respectively (kappa = 0.83). In 8 patients, CT revealed more rib fractures than autopsy; and in 12 patients, autopsy revealed more rib fractures than CT. In 7 patients, neither method showed any rib fractures. The mean difference between the two methods in detecting rib fractures was 0.16 (S.D.: ±3.174, limits of agreement: −6.19 to 6.51). The kappa value for sternal fractures was 0.49. A total of 260 pathological findings were noted by CT and 244 by autopsy. The average patient showed a median of 9 injuries (every fracture counted as one injury), independent of the method used in detecting the injuries.

Conclusions

There was a strong concordance between the two methods in finding rib fractures but not sternal fractures and these results support the concept of CT as a valuable complement to autopsy in detecting rib fractures after unsuccessful cardiopulmonary resuscitation but not as a replacement. Other injuries did not show the same concordance.     

Continuous mechanical chest compression during in-hospital cardiopulmonary resuscitation of patients with pulseless electrical activity

Survival after in-hospital pulseless electrical activity (PEA) cardiac arrest is poor and has not changed during the last 10 years. Effective chest compressions may improve survival after PEA. We investigated whether a mechanical device (LUCAS™-CPR) can ensure chest compressions during cardiac arrest according to guidelines and without interruption during transport, diagnostic procedures and in the catheter laboratory.

Methods

We studied mechanical chest compression in 28 patients with PEA (pulmonary embolism (PE) n = 14; cardiogenic shock/acute myocardial infarction; n = 9; severe hyperkalemia; n = 2; sustained ventricular arrhythmias/electrical storm; n = 3) in a university hospital setting.

Results

During or immediately after CPR, 21 patients underwent coronary angiography and or pulmonary angiography. Successful return of a spontaneous circulation (ROSC) was achieved in 27 out of the 28 patients. Ten patients died within the first hour and three patients died within 24 h after CPR. A total of 14 patients survived and were discharged from hospital (13 without significant neurological deficit). Interestingly, six patients with PE did not have thrombolytic therapy due to contraindications. CT-angiography findings in these patients showed fragmentation of the thrombus suggesting thrombus breakdown as an additional effect of mechanical chest compressions. No patients exhibited any life-threatening device-related complications.

Conclusion

Continuous chest compression with an automatic mechanical device is feasible, safe, and might improve outcomes after in-hospital-resuscitation of PEA. Patients with PE may benefit from effective continuous chest compression, probably due to thrombus fragmentation and increased pulmonary artery blood flow.     

Comparison of shock-first strategy and cardiopulmonary resuscitation-first strategy in a porcine model of prolonged cardiac arrest

Objective

The choice of a shock-first or a cardiopulmonary resuscitation (CPR)-first strategy in the treatment of prolonged cardiac arrest (CA) is still controversial. The purpose of this study was to compare the effects of these strategies on oxygen metabolism and resuscitation outcomes in a porcine model of 8 min CA.

Methods

Ventricular fibrillation (VF) was electrically induced. After 8 min of untreated VF, 24 male inbred Wu-Zhi-Shan miniature pigs were randomized to receive either defibrillation first (ID group) or chest compression first (IC group). In the ID group, a shock was delivered immediately. If the defibrillation attempt failed to attain restoration of spontaneous circulation (ROSC), manual chest compressions were rapidly initiated at a rate of 100 compressions min⁻¹, and the compression-to-ventilation ratio was 30:2. If VF persisted after five cycles of CPR, a second defibrillation attempt was made. In the IC group, chest compressions were delivered first, followed by a shock.

Results

Hemodynamic variables, the VF waveform and blood gas analysis outcomes were recorded. Oxygen metabolism parameters and the amplitude spectrum area (AMSA) of the VF waveform were computed. There were no significant differences in the rate of ROSC and 24 h survival between two groups. The ID group had lower lactic acid levels, higher cardiac output, better oxygen consumption and better oxygen extraction ratio at 4 and 6 h after ROSC than the IC group.

Conclusions

In a porcine model of prolonged CA, the choice of a shock-first or CPR-first strategy did not affect the rate of ROSC and 24 h survival, but the shock-first strategy might result in better hemodynamic status and better oxygen metabolism than the CPR-first strategy at the first 6 h after ROSC.     

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.     

Forensic analysis of crib mattress properties on pediatric CPR quality—Can we balance pressure reduction with CPR effectiveness?

Introduction

Single mode, pressure reduction (PR) crib mattresses are increasingly employed in hospitals to prevent skin injury and infection. However, single mode PR mattresses risk large mattress deflection during CPR chest compressions, potentially leading to inadequate chest compressions.

Hypothesis

New, dual mode PR crib mattress technology provides less mattress deflection during chest compressions (CCs) with similar PR characteristics for prevention of skin injury.

Methods

Epochs of 50 high-quality CCs (target sternum–spine compression depth ≥38 mm) guided by real-time force/deflection sensor (FDS) feedback were delivered to CPR manikin with realistic CC characteristics on two PR crib mattresses for four conditions: (1) single mode + backboard; (2) dual mode + backboard; (3) single mode − no backboard; and (4) dual mode − no backboard. Mattress displacement was measured using surface reference accelerometers. Mattress displacement ≥5 mm was prospectively defined as minimal clinically important difference. PR qualities of both mattresses were assessed by tissue interface pressure mapping.

Results

During simulated high quality CC, single mode had significantly more mattress displacement compared to dual mode (mean difference 16.5 ± 1.4 mm, p < 0.0001) with backboard. This difference was greater when no backboard was used (mean difference 31.7 ± 1.5 mm, p < 0.0001). Both single mode and dual mode met PR industry guidelines (mean surface pressure <50 mmHg).

Conclusions

Chest compressions delivered on dual mode pressure reduction crib mattresses resulted in substantially smaller mattress deflection compared to single mode pressure reduction mattresses. Skin pressure reduction qualities of dual mode pressure reduction crib mattress were maintained. We recommend that backboards continue to be used in order to mitigate mattress deflection during CPR on soft mattresses.     

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.