Pushing harder,pushing faster,minimizing interruptions… But falling short of 2010 cardiopulmonary resuscitation targets during in-hospital pediatric and adolescent resuscitation

Aim

The objective of this study was to evaluate the effect of instituting the 2010 Basic Life Support Guidelines on in-hospital pediatric and adolescent cardiopulmonary resuscitation (CPR) quality. We hypothesized that quality would improve, but that targets for chest compression (CC) depth would be difficult to achieve.

Methods

Prospective in-hospital observational study comparing CPR quality 24 months before and after release of the 2010 Guidelines. CPR recording/feedback-enabled defibrillators collected CPR data (rate (CC/min), depth (mm), CC fraction (CCF, %), leaning (% > 2.5 kg)). Audiovisual feedback for depth was: 2005, ≥38 mm; 2010, ≥50 mm; for rate: 2005, ≥90 and ≤120 CC/min; 2010, ≥100 and ≤120 CC/min. The primary outcome was average event depth compared with Student's t-test.

Results

45 CPR events (25 before; 20 after) occurred, resulting in 1336 thirty-second epochs (909 before; 427 after). Compared to 2005, average event depth (50 ± 13 mm vs. 43 ± 9 mm; p = 0.047), rate (113 ± 11 CC/min vs. 104 ± 8 CC/min; p < 0.01), and CCF (0.94 [0.93, 0.96] vs. 0.9 [0.85, 0.94]; p = 0.013) increased during 2010. CPR epochs during the 2010 period more likely to meet Guidelines for CCF (OR 1.7; CI95: 1.2–2.4; p < 0.01), but less likely for rate (OR 0.23; CI95: 0.12–0.44; p < 0.01), and depth (OR 0.31; CI95: 0.12–0.86; p = 0.024).

Conclusions

Institution of the 2010 Guidelines was associated with increased CC depth, rate, and CC fraction; yet, achieving 2010 targets for rate and depth was difficult.     

First quantitative analysis of cardiopulmonary resuscitation quality during in-hospital cardiac arrests of young children

Aim

The objective of this study is to report, for the first time, quantitative data on CPR quality during the resuscitation of children under 8 years of age. We hypothesized that the CPR performed would often not achieve 2010 Pediatric Basic Life Support (BLS) Guidelines, but would improve with the addition of audiovisual feedback.

Methods

Prospective observational cohort evaluating CPR quality during chest compression (CC) events in children between 1 and 8 years of age. CPR recording defibrillators collected CPR data (rate (CC/min), depth (mm), CC fraction (CCF), leaning (%> 2.5 kg.)). Audiovisual feedback was according to 2010 Guidelines in a subset of patients. The primary outcome, “excellent CPR” was defined as a CC rate ≥100 and ≤120 CC/min, depth ≥50 mm, CCF >0.80, and <20% of CC with leaning.

Results

8 CC events resulted in 285 thirty-second epochs of CPR (15,960 CCs). Percentage of epochs achieving targets was 54% (153/285) for rate, 19% (54/285) for depth, 88% (250/285) for CCF, 79% (226/285) for leaning, and 8% (24/285) for excellent CPR. The median percentage of epochs per event achieving targets increased with audiovisual feedback for rate [88 (IQR: 79, 94) vs. 39 (IQR 18, 62) %; p = 0.043] and excellent CPR [28 (IQR: 7.2, 52) vs. 0 (IQR: 0, 1) %; p = 0.018].

Conclusions

In-hospital pediatric CPR often does not meet 2010 Pediatric BLS Guidelines, but compliance is better when audiovisual feedback is provided to rescuers.     

Hemodynamic directed CPR improves short-term survival from asphyxia-associated cardiac arrest

Aim

Adequate coronary perfusion pressure (CPP) during cardiopulmonary resuscitation (CPR) is essential for establishing return of spontaneous circulation. The objective of this study was to compare short-term survival using a hemodynamic directed resuscitation strategy versus an absolute depth-guided approach in a porcine model of asphyxia-associated cardiac arrest. We hypothesized that a hemodynamic directed approach would improve short-term survival compared to depth-guided care.

Methods

After 7 min of asphyxia, followed by induction of ventricular fibrillation, 19 female 3-month old swine (31 ± 0.4 kg) were randomized to receive one of three resuscitation strategies: (1) hemodynamic directed care (CPP-20): chest compressions (CCs) with depth titrated to a target systolic blood pressure of 100 mmHg and titration of vasopressors to maintain CPP > 20 mmHg; (2) depth 33 mm (D33): target CC depth of 33 mm with standard American Heart Association (AHA) epinephrine dosing; or (3) depth 51 mm (D51): target CC depth of 51 mm with standard AHA epinephrine dosing. All animals received manual CPR guided by audiovisual feedback for 10 min before first shock.

Results

45-Min survival was higher in the CPP-20 group (6/6) compared to D33 (1/7) or D51 (1/6) groups; p = 0.002. Coronary perfusion pressures were higher in the CPP-20 group compared to D33 (p = 0.011) and D51 (p = 0.04), and in survivors compared to non-survivors (p < 0.01). Total number of vasopressor doses administered and defibrillation attempts were not different.

Conclusions

Hemodynamic directed care targeting CPPs > 20 mmHg improves short-term survival in an intensive care unit porcine model of asphyxia-associated cardiac arrest.     

The relationship between chest compression fraction and outcome from ventricular fibrillation arrests in prolonged resuscitations

Background

Guidelines direct rescuers to minimize CPR interruptions during resuscitation. There is little evidence that evaluates the relationship of increasing CPR fraction among patients with relatively high fractions or prolonged resuscitation.

Methods

We conducted an observational study of persons who suffered out-of-hospital ventricular fibrillation arrest and required >5 min of emergency medical services (EMS) CPR for persistent pulselessness. We determined the association between hands-on CPR fraction and outcomes of spontaneous circulation, survival to hospital discharge, and neurologically favorable survival. Analyses were stratified by median hands-on CPR and were conducted for those who required 5, 10, and 20 min of EMS CPR for persistent pulselessness.

Results

Of 414 potentially eligible patients, 323 (78%) required >5 min of EMS CPR, 234 (56%) required >10 min of EMS CPR, and 153 (37%) required EMS CPR for >20 min. The median CPR fraction was 81%. We did not observe a significant association for the outcomes of hospital survival and neurologically favorable survival for the 5-min and 10-min groups. When restricted to patients who required >20 min of EMS CPR, the half who received a higher hands-on CPR fraction were more likely to achieve spontaneous circulation (40% versus 18%, p = 0.004), survival to hospital discharge (20% versus 8%, p = 0.03), and neurologically favorable survival (20% versus 7%, p = 0.02).

Conclusion

Over one-third required 20 min of persistent EMS CPR. The EMS was able to achieve a high hands-on CPR fraction in the context of advanced therapies. Those who required the most prolonged EMS CPR appeared to benefit from greater hands-on CPR fraction.     

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.     

Beyond the pre-shock pause: the effect of prehospital defibrillation mode on CPR interruptions and return of spontaneous circulation

Aims

The pattern of interruptions to chest compressions in pre-hospital cardiac arrests in Wellington, New Zealand, was examined prospectively to determine whether the mode of defibrillation chosen by paramedics influenced interruptions, shock success and the return of spontaneous circulation (ROSC).

Methods

A prospective observational cohort study of 44 adult cardiac arrests in which 203 shocks were administered by Wellington Free Ambulance (WFA) paramedics was undertaken to compare Code-stat^® electronic records from Medtronic^® Lifepak 12 and Lifepak 15 defibrillators used in semi-automated (AED) or manual mode. Interruptions during the 30 s prior to shock delivery as well as pre-shock and post-shock pauses were calculated. Shock success and ROSC were the outcome measures.

Results

Pre-shock pauses were shorter in manual mode (median 3 s, IQR 2–5) versus AED mode (median 4 s, IQR 3–6; p = 0.003). Interruptions of CPR in the 30 s prior to shock delivery were also shorter in manual mode (median 7 s, IQR 4–11) versus AED mode (median 14 s, IQR 12–16; p = <0.001). Shock success rates and post-shock pauses were not statistically different between modes. ROSC was significantly higher in manual mode (18.49%) versus AED mode (8.33%, p = 0.042).

Conclusion

When paramedics used the defibrillator in manual mode as compared to AED mode, interruptions to CPR during the 30 s prior to shock delivery were significantly reduced and pre-shock pauses were also shorter. This was associated with increased ROSC. Manual defibrillation should be the preferred option for appropriately trained paramedics. Training in this locality has been changed accordingly.     

American Heart Association cardiopulmonary resuscitation quality targets are associated with improved arterial blood pressure during pediatric cardiac arrest

Aim

To evaluate the association between cardiopulmonary resuscitation (CPR) quality and hemodynamic measurements during in-hospital pediatric cardiac arrest. We hypothesized that AHA recommended CPR rate and depth targets would be associated with systolic blood pressures ≥ 80 mmHg and diastolic blood pressures ≥ 30 mmHg.

Methods

In children and adolescents <18 years of age who suffered a cardiac arrest with an invasive arterial catheter in place, a CPR monitoring defibrillator collected CPR data which was synchronized to arterial blood pressure (BP) tracings. Chest compression (CC) depths were corrected for mattress deflection. Generalized least squares regression estimated the association between BP and CPR quality, treated as continuous variables. Mixed-effects logistic regression estimated the association between systolic BP ≥ 80 mmHg/diastolic BP ≥ 30 mmHg and the AHA targets of depth ≥ 38 mm and/or rate ≥ 100/min.

Results

Nine arrests resulted in 4156 CCs. The median mattress corrected depth was 32 mm (IQR 28–38); median rate was 111 CC/min (IQR 103–120). AHA depth was achieved in 1090/4156 (26.2%) CCs; rate in 3441 (83.7%). Systolic BP ≥ 80 mmHg was attained in 2516/4156 (60.5%) compressions; diastolic ≥ 30 mmHg in 2561/4156 (61.6%). A rate ≥ 100/min was associated with systolic BP ≥ 80 mmHg (OR 1.32; CI⁹⁵ 1.04, 1.66; p = 0.02) and diastolic BP ≥ 30 mmHg (OR 2.15; CI⁹⁵ 1.65, 2.80; p < 0.001). Exceeding both (rate ≥ 100/min and depth ≥ 38 mm) was associated with systolic BP ≥ 80 mmHg (OR 2.02; CI⁹⁵ 1.45, 2.82; p < 0.001) and diastolic BP ≥ 30 mmHg (OR 1.48; CI⁹⁵ 1.01, 2.15; p = 0.042).

Conclusions

AHA quality targets (rate ≥ 100/min and depth ≥ 38 mm) were associated with systolic BPs ≥ 80 mmHg and diastolic BPs ≥ 30 mmHg during CPR in children.     

Influence of nationwide policy on citizens’ awareness and willingness to perform bystander cardiopulmonary resuscitation

Aims

Public awareness to cardiopulmonary resuscitation (CPR) and cardiac arrest is influenced by systemic factors including related policies and legislations in the community. Here, we describe and compare the results of the two nationwide CPR surveys in 2007 and 2011 examining public awareness and attitudes to bystander CPR in South Korea along with changes in nationwide CPR policies and systemic factors.

Methods

This population-based study used specially designed questionnaires via telephone surveys. We conducted bi-temporal surveys by stratified cluster sampling to assess the impact of age, gender, and geographic regions in 2007 (n = 1029) and in 2011 (n = 1000). Logistic regression analysis was performed to identify factors associated with willingness to perform bystander CPR.

Results

Public awareness of automated external defibrillators increased from 3.0% in 2007 to 32.6% in 2011. The proportion of the population that underwent CPR training within the previous 2 years increased significantly from 26.9% to 49.0%. The factors most related with intention of bystander CPR were male gender, younger age, CPR awareness, recent CPR training, and qualified CPR learning. In 2011, 75.8% of respondents were more willing to perform bystander CPR for stranger vs. 68.3% in 2007 (p = 0.002). Additional dispatcher hands-only CPR increased this proportion (85.8%, p < 0.001). However, bystander CPR experience rates remained unchanged (3.6–3.9%).

Conclusion

Changes in nationwide CPR policies and systemic factors affected citizens’ awareness and willingness to perform bystander CPR. Additionally, applied dispatcher hands-only CPR and publicity increased public willingness to perform bystander CPR.     

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.     

2010 American Heart Association recommended compression depths during pediatric in-hospital resuscitations are associated with survival

Aim

Gaps exist in pediatric resuscitation knowledge due to limited data collected during cardiac arrest in real children. The objective of this study was to evaluate the relationship between the 2010 American Heart Association (AHA) recommended chest compression (CC) depth (≥51 mm) and survival following pediatric resuscitation attempts.

Methods

Single-center prospectively collected and retrospectively analyzed observational study of children (>1 year) who received CCs between October 2006 and September 2013 in the intensive care unit (ICU) or emergency department (ED) at a tertiary care children's hospital. Multivariate logistic regression models controlling for calendar year and known potential confounders were used to estimate the association between 2010 AHA depth compliance and survival outcomes. The primary outcome was 24-h survival. The primary predictor variable was event AHA depth compliance, prospectively defined as an event with ≥60% of 30-s epochs achieving an average CC depth ≥51 mm during the first 5 min of the resuscitation.

Results

There were 89 CC events, 87 with quantitative CPR data collected (23 AHA depth compliant). AHA depth compliant events were associated with improved 24-h survival on both univariate analysis (70% vs. 16%, p < 0.001) and after controlling for potential confounders (calendar year of arrest, gender, first documented rhythm; aOR 10.3; CI⁹⁵: 2.75–38.8; p < 0.001).

Conclusions

2010 AHA compliant chest compression depths (≥51 mm) are associated with higher 24-h survival compared to shallower chest compression depths, even after accounting for potentially confounding patient and event factors.     

A Simple Audio-visual Prompt Device Can Improve CPR Performance

Background

An adjunct to assist cardiopulmonary resuscitation (CPR) might improve the quality of CPR performance.

Study Objectives

This study was conducted to evaluate whether a simple audio-visual prompt device improves CPR performance by emergency medical technicians (EMTs).

Methods

From June 2008 to October 2008, 55 EMTs (39 men, mean age 34.9 ± 4.8 years) participated in this study. A simple audio-visual prompt device was developed. The device generates continuous metronomic sounds for chest compression at a rate of 100 beats/min with a distinct 30^th sound followed by two respiration sounds, each for 1 second. All EMTs were asked to perform a 2-min CPR series on a manikin without the device, and one 2-min CPR series with the device.

Results

The average rate of chest compressions was more accurate when the device was used than when the device was not used (101.4 ± 12.7 vs. 109.0 ± 17.4/min, respectively, p = 0.012; 95% confidence interval [CI] 97.2–103.8 vs. 104.5–113.5/min, respectively), and hands-off time during CPR was shorter when the device was used than when the device was not used (5.4 ± 0.9 vs. 9.2 ± 3.9 s, respectively, p < 0.001; 95% CI 5.2–5.7 vs. 8.3–10.3 s, respectively). The mean tidal volume during CPR with the device was lower than without the device, resulting in the prevention of hyperventilation (477.6 ± 60.0 vs. 636.6 ± 153.4 mL, respectively, p < 0.001; 95% CI 463.5–496.2 vs. 607.3–688.9 mL, respectively).

Conclusion

A simple audio-visual prompt device can improve CPR performance by emergency medical technicians.     

Animation-assisted CPRII program as a reminder tool in achieving effective one-person-CPR performance

Objective

The objective of this study is to compare the skill retention of two groups of lay persons, six months after their last CPR training. The intervention group was provided with animation-assisted CPRII (AA-CPRII) instruction on their cellular phones, and the control group had nothing but what they learned from their previous training.

Methods

This study was a single blind randomized controlled trial. The participants’ last CPR trainings were held at least six months ago. We revised our CPR animation for on-site CPR instruction content emphasizing importance of chest compression. Participants were randomized into two groups, the AA-CPRII group (n = 42) and the control group (n = 38). Both groups performed three cycles of CPR and their performances were video recorded. These video clips were assessed by three evaluators using a checklist. The psychomotor skills were evaluated using the Resusci^®Anne SkillReporter™.

Results

Using the 30-point scoring checklist, the AA-CPRII group had a significantly better score compared to the control group (p < 0.001). Psychomotor skills evaluated with the AA-CPRII group demonstrated better performance in hand positioning (p = 0.025), compression depth (p = 0.035) and compression rate (p < 0.001) than the control group.

Conclusion

The AA-CPRII group resulted in better checklist scores, including chest compression rate, depth and hand positioning. Animation-assisted CPR could be used as a reminder tool in achieving effective one-person-CPR performance. By installing the CPR instruction on cellular phones and having taught them CPR with it during the training enabled participants to perform better CPR.     

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.     

Early coronary revascularization improves 24 h survival and neurological function after ischemic cardiac arrest. A randomized animal study

Background

Survival after out-of-hospital cardiac arrest (OHCA) remains poor. Acute coronary obstruction is a major cause of OHCA. We hypothesize that early coronary reperfusion will improve 24 h-survival and neurological outcomes.

Methods

Total occlusion of the mid LAD was induced by balloon inflation in 27 pigs. After 5 min, VF was induced and left untreated for 8 min. If return of spontaneous circulation (ROSC) was achieved within 15 min (21/27 animals) of cardiopulmonary resuscitation (CPR), animals were randomized to a total of either 45 min (group A) or 4 h (group B) of LAD occlusion. Animals without ROSC after 15 min of CPR were classified as refractory VF (group C). In those pigs, CPR was continued up to 45 min of total LAD occlusion at which point reperfusion was achieved. CPR was continued until ROSC or another 10 min of CPR had been performed. Primary endpoints for groups A and B were 24-h survival and cerebral performance category (CPC). Primary endpoint for group C was ROSC before or after reperfusion.

Results

Early compared to late reperfusion improved survival (10/11 versus 4/10, p = 0.02), mean CPC (1.4 ± 0.7 versus 2.5 ± 0.6, p = 0.017), LVEF (43 ± 13 versus 32 ± 9%, p = 0.01), troponin I (37 ± 28 versus 99 ± 12, p = 0.005) and CK-MB (11 ± 4 versus 20.1 ± 5, p = 0.031) at 24-h after ROSC. ROSC was achieved in 4/6 animals only after reperfusion in group C.

Conclusions

Early reperfusion after ischemic cardiac arrest improved 24 h survival rate and neurological function. In animals with refractory VF, reperfusion was necessary to achieve ROSC.     

Miniaturized mechanical chest compressor improves calculated cerebral perfusion pressure without compromising intracranial pressure during cardiopulmonary resuscitation in a porcine model of cardiac arrest

Objective

One of the major goals of cardiopulmonary resuscitation (CPR) is to provide adequate oxygen delivery to the brain for minimizing cerebral injury resulted from cardiac arrest. The optimal chest compression during CPR should effectively improve brain perfusion without compromising intracranial pressure (ICP). Our previous study has demonstrated that the miniaturized mechanical chest compressor improved hemodynamic efficacy and the success of CPR. In the present study, we investigated the effects of the miniaturized chest compressor (MCC) on calculated cerebral perfusion pressure (CerPP) and ICP.

Methods

Ventricular fibrillation was electrically induced and untreated for 7 min in 13 male domestic pigs weighing 39 ± 3 kg. The animals were randomized to receive mechanical chest compression with the MCC (n = 7), or the Thumper device (n = 6). CPR was performed for 5 min before defibrillation attempt by a single 150 J shock. At 2.5 min of CPR, the epinephrine at a dose of 20 μg/kg was administered. Additional epinephrine was administered at an interval of 3 min thereafter. If resuscitation was not successful, CPR was resumed for an additional 2 min prior to the next defibrillation until successful resuscitation or for a total of 15 min. Post-resuscitated animals were observed for 2 h.

Results

Significantly greater intrathoracic positive and negative pressures during compression and decompression phases of CPR were observed with the MCC when compared with the Thumper device. The MCC produced significantly greater coronary perfusion pressure and end-tidal carbon dioxide. There were no statistically significant differences in systolic and mean ICP between the two groups; however, both of the measurements were slightly greater in the MCC treated animals. Interestingly, the diastolic ICP was significantly lower in the MCC group, which was closely related to the significantly lower negative intrathoracic pressure in the animals that received the MCC. Most important, systolic, diastolic and mean calculated CerPP were all significantly greater in the animals receiving the MCC.

Conclusions

In the present study, mechanical chest compression with the MCC significantly improved calculated CerPP but did not compromise ICP during CPR. It may provide a safe and effective chest compression during CPR.Protocol number: P1205.     

Performing bystander CPR for sudden cardiac arrest: Behavioral intentions among the general adult population in Arizona

Study objectives

The odds of surviving an out-of-hospital cardiac arrest are significantly improved by the provision of bystander cardiopulmonary resuscitation (CPR), but many cardiac arrest victims do not receive it. The existing literature remains equivocal as to why people are unwilling to perform traditional CPR. This study's objectives were to determine the behavioral intentions of the general population in Arizona regarding performing bystander CPR and to assess the reasons for being unwilling to perform CPR.

Methods

This was a general population survey using a mailed, self-administered questionnaire. The questionnaire was mailed to random samples of Arizona residents in a rural and urban county.

Results

Usable questionnaires were received from 49.5% (n = 370) and 49.6% (n = 385) of the samples from the urban and rural county, respectively. More than 50% of respondents reported being willing to perform CPR on a stranger and over 80% reported being willing to perform CPR on a family member. There were no significant differences between the proportions of respondents in each county willing to perform CPR. The reasons for not being willing to perform CPR were relatively evenly divided among the five reasons listed.

Conclusions

Although our findings likely overestimate the proportion of individuals who would perform bystander CPR, the relative importance of the reasons for not performing CPR is informative. Based on the reasons reported, there is potential to change the CPR-related attitudes, beliefs, and skill levels of the general public to enhance the number of people willing and able to perform bystander CPR.     

Hemodynamic directed CPR improves cerebral perfusion pressure and brain tissue oxygenation

Aim

Advances in cardiopulmonary resuscitation (CPR) have focused on the generation and maintenance of adequate myocardial blood flow to optimize the return of spontaneous circulation and survival. Much of the morbidity associated with cardiac arrest survivors can be attributed to global brain hypoxic ischemic injury. The objective of this study was to compare cerebral physiological variables using a hemodynamic directed resuscitation strategy versus an absolute depth-guided approach in a porcine model of ventricular fibrillation (VF) cardiac arrest.

Methods

Intracranial pressure and brain tissue oxygen tension probes were placed in the frontal cortex prior to induction of VF in 21 female 3-month-old swine. After 7 min of VF, animals were randomized to receive one of three resuscitation strategies: (1) hemodynamic directed care (CPP-20): chest compressions (CCs) with depth titrated to a target systolic blood pressure of 100 mmHg and titration of vasopressors to maintain coronary perfusion pressure (CPP) >20 mmHg; (2) depth 33 mm (D33): target CC depth of 33 mm with standard American Heart Association (AHA) epinephrine dosing; or (3) depth 51 mm (D51): target CC depth of 51 mm with standard AHA epinephrine dosing.

Results

Cerebral perfusion pressures (CerePP) were significantly higher in the CPP-20 group compared to both D33 (p < 0.01) and D51 (p = 0.046), and higher in survivors compared to non-survivors irrespective of treatment group (p < 0.01). Brain tissue oxygen tension was also higher in the CPP-20 group compared to both D33 (p < 0.01) and D51 (p = 0.013), and higher in survivors compared to non-survivors irrespective of treatment group (p < 0.01). Subjects with a CPP >20 mmHg were 2.7 times more likely to have a CerePP >30 mmHg (p < 0.001).

Conclusions

Hemodynamic directed resuscitation strategy targeting coronary perfusion pressure >20 mmHg following VF arrest was associated with higher cerebral perfusion pressures and brain tissue oxygen tensions during CPR.     

Quality of chest compressions performed by inexperienced rescuers in simulated cardiac arrest associated with pregnancy

Objective

We aimed to compare the quality of chest compressions performed by inexperienced rescuers in different positions, notably supine and at a 30° inclined lateral position, to ascertain whether high-quality chest compression is feasible on a pregnant subject in cardiac arrest.

Subjects and methods

We performed a prospective, randomised crossover design study. Each participant performed 2-min chest compressions in two different positions on a mannequin: a supine position and a 30° left inclined lateral position. After 2 min of chest compression in one position, the participant took a rest for 10 min to minimise rescuer fatigue and then performed chest compression in the second position. Data on chest compression rate, mean chest compression depth, correct compression depth rate, correct recoil rate, and correct hand position rate were collected. To measure the angle between the rescuer's arm and the victim's chest surface, chest compressions were recorded with a video recorder. After each practice session, participants were asked to report the subjective difficulty of performing chest compressions using a visual analogue scale.

Results

All 32 participants successfully completed the study. The mean compression rate and depth were 121.0 per minute and 53.3 mm in the supine position and 118.8 per minute and 52.0 mm in the inclined lateral position, respectively (p = 0.978 and p = 0.260, respectively). Also, there were no differences in the correct compression depth rate, the correct hand position rate, or the correct recoil rate (p = 0.426, p = 0.467, and p = 0.260, respectively). However, the lowest and highest angles and the subjective difficulty of chest compression differed significantly (p < 0.001, p < 0.001, and p = 0.007, respectively).

Conclusions

Inexperienced rescuers appear to be capable of performing high-quality chest compressions in a 30° inclined lateral position on pregnant women in a simulated cardiac arrest state.