Continuous Mechanical Chest Compressions Research Articles

Comparison of different mechanical chest compression devices in the alpine rescue setting: a randomized triple crossover experiment

BackgroundCardiopulmonary resuscitation in mountain environment is challenging. Continuous chest compressions during transport or hoist rescue are almost impossible without mechanical chest compression devices. Current evidence is predominantly based on studies conducted by urbane ambulance service. Therefore, we aimed to investigate the feasibility of continuous mechanical chest compression during alpine terrestrial transport using three different devices.MethodsRandomized triple crossover prospective study in an alpine environment. Nineteen teams of the Austrian Mountain Rescue Service trained according to current ERC guidelines performed three runs each of a standardised alpine rescue-scenario, using three different devices for mechanical chest compression. Quality of CPR, hands-off-time and displacement of devices were measured.ResultsThe primary outcome of performed work (defined as number of chest compressions x compression depth) was 66,062 mm (2832) with Corpuls CPR, 65,877 mm (6163) with Physio-Control LUCAS 3 and 40,177 mm (4396) with Schiller Easy Pulse. The difference both between LUCAS 3 and Easy Pulse (Δ 25,700; 95% confidence interval 21,118 – 30,282) and between Corpuls CPR and Easy Pulse (Δ 25,885; 23,590 – 28,181) was significant. No relevant differences were found regarding secondary outcomes.ConclusionMechanical chest compression devices provide a viable option in the alpine setting. For two out of three devices (Corpuls CPR and LUCAS 3) we found adequate quality of CPR. Those devices also maintained a correct placement of the piston even during challenging terrestrial transport. Adequate hands-off-times and correct placement could be achieved even by less trained personnel.

Abstract 459: The TripleCPR 16 Study: Does Rhythm Truly Needed to Be Checked Every 2 Minutes in Cardiopulmonary Arrest Patients?

Purpose: Current guidelines recommend rhythm checks every 2 minutes during CPR, but evidence for this recommendation is insufficient. Recent reports identified regional cerebral oxygen saturation (rSO 2 ) monitoring as useful in detecting ROSC and that coronary and cerebral perfusion decrease with the 2-minute rhythm check. On the basis of our previous study, we began the TripleCPR 16 study, which omits 2-minute rhythm checks because stopping chest compression to check rhythm may increase cerebral damage and decrease the ROSC. Methods: The multicenter, prospective TripleCPR 16 study began in January 2017. The inclusion criterion is a cardiopulmonary arrest patient aged ≥16 years with a non-shockable rhythm on hospital arrival. Subjects are divided into 3 groups based on their mean cerebral rSO 2 value in the first minute of arrival: ≥50%, <50% to 40%, and <40%. Continuous mechanical chest compression is performed on all subjects for 16 minutes or until their rSO 2 value exceeds the initial value by 10%, 20%, or 35%, respectively. We are comparing the TripleCPR 16 study results with our previous hospital data obtained from 86 patients with non-shockable rhythm who underwent every 2-minute rhythm checks and mechanical chest compression. Result: Currently, 218 patients are registered. Rates of ROSC were 34.9% for these patients and 39.5% for the previous 86 patients (p=0.51). There were no severe adverse events. Subanalysis of the data of Osaka University Hospital alone showed no significant increase of rSO 2 value in the 48 patients with non-sonographic cardiac activity and 26 patients with Stanford type A aortic dissection diagnosed by CT scan, and only two patient in each group achieved ROSC. When excluding the patients with Stanford type A aortic dissection, rates of ROSC was 47.8% for the patients in this study and 39.0% for the previous 86 patients (p=0.26). Conclusion: The TripleCPR 16 study is ongoing without severe adverse events. In the patients with non-sonographic cardiac activity or Stanford type A aortic dissection, rSO 2 values did not increase and it was difficult to achieve ROSC. A simpler CPR protocol could be devised that omits the 2-minute rhythm check in patients with a non-shockable rhythm.

Abstract 209: The Triple CPR 16 study: Does rhythm truly needed to be checked every 2 minutes in Cardiopulmonary Arrest Patients?

Purpose: Current guidelines recommend rhythm checks every 2 minutes during cardiopulmonary resuscitation (CPR), but evidence for this recommendation is insufficient. Recent reports identified regional cerebral oxygen saturation (rSO 2 ) monitoring as useful in detecting return of spontaneous resuscitation (ROSC) and that coronary and cerebral perfusion decreases with the 2-minute rhythm check. On the basis of our previous study, we began the TripleCPR 16 study, which omits 2-minute rhythm checks because stopping chest compression to check rhythm may increase cerebral damage and decrease the ROSC. Methods: The multicenter, prospective TripleCPR 16 study began in January 2017. The inclusion criterion is a cardiopulmonary arrest patient aged ≥16 years with a non-shockable rhythm on hospital arrival. Subjects are divided into 3 groups based on their mean cerebral rSO 2 value in the first minute of arrival: ≥50%, <50% to 40%, and <40%. Continuous mechanical chest compression is performed on all subjects for 16 minutes or until their rSO 2 value exceeds the initial value by 10%, 20%, or 35%, respectively. We are comparing the TripleCPR 16 study results with our previous hospital data obtained from 90 patients who underwent every 2-minute rhythm checks and mechanical chest compression. Result: Currently, 162 patients are registered. Rates of ROSC were 32.1% for these patients and 38.9% for the previous 90 patients (p=0.33). There were no severe adverse events. Subanalysis of the data of Osaka University Hospital alone showed no significant increase of rSO 2 value in the 24 patients with non-sonographic cardiac activity and 21 patients with Stanford type A aortic dissection diagnosed by CT scan, and only one patient in each group achieved ROSC. When excluding the patients with Stanford type A aortic dissection, rates of ROSC were 49.4% for the patients in this study and 39.3% for the previous 90 patients (p=0.21). Conclusion: The TripleCPR 16 study is ongoing without severe adverse events. In the patients with non-sonographic cardiac activity or Stanford type A aortic dissection, rSO 2 values did not increase and it was difficult to achieve ROSC. The 2-minute rhythm check is not essential for chest compression in patients with a non-shockable rhythm.

Comparison of the GlideScope® with the Macintosh Laryngoscope in Endotracheal Intubation during Uninterrupted Mechanical Chest Compression: A Randomised Crossover Manikin Study

Background The GlideScope® (GS) has been shown to improve the first-attempt success rate of endotracheal intubation during continuous mechanical chest compressions compared with the conventional Macintosh laryngoscope (ML) in inexperienced hands. Yet, its value for operators with experience of emergency airway management has remained uncertain. We set out to compare their performance in the hands of experienced operators in a manikin receiving continuous mechanical chest compressions delivered by LUCAS®. Method This was a randomised crossover study. Thirty-five emergency physicians and intensivists performed intubation using GS and ML in 3 different scenarios: (1) normal airway without chest compressions; (2) normal airway with uninterrupted mechanical chest compressions; and (3) normal airway with cervical spine (C-spine) immobilisation and uninterrupted mechanical chest compressions. The sequence of scenarios and devices used were randomised. The primary outcome was the first-attempt success rate of intubation. Other data including demographics, the time required for successful intubation, complications during intubation, the visual analog scale of perceived difficulty of intubation and the preference on devices in each scenario were also collected and analyzed. Results In scenario 1, the first-attempt success rate with both laryngoscopes was 100%. In scenario 2, there was a higher first-attempt success rate with ML but it was not statistically significant (GS 97.14% vs ML 100%, p=1.00). In scenario 3, one participant failed to intubate in the first attempt with each of the laryngoscopes (GS 97.14% vs ML 97.14%, p=0.754). More dental compression was noted with GS but the difference was not statistically significant (GS 42.86% vs ML 22.86%, p=0.126). Overall, the median time for intubation with GS was significantly longer in all 3 scenarios (Scenario 1: GS 18.5s; interquartile range [IQR] 13.8 -22.2s vs ML 11.2s, IQR 9.5-14.2s, p<0.001; Scenario 2: GS 18.7s, IQR 13.1-25.2s vs ML 13.4s, 10.3-15.8s, p<0.001; Scenario 3: GS 20.8s, IQR 16.5-29.2s vs ML 14.0s, IQR 10.5-18.0s, p<0.001). More participants preferred GS in scenario 3, while ML remained the device of choice in the other two scenarios. Conclusion: GS is not superior to ML in terms of the first-attempt success rate of intubation and it takes significantly longer to intubate for experienced operator. Yet more participants prefer its use when the C-spine motion is limited. Further studies are warranted to explore its role in trauma resuscitation. (Hong Kong j.emerg.med. 2016;23:159-167)

Abstract 19325: Hemodynamic Effects of Guideline-compliant Asynchronous vs. Synchronous Ventilations During Cardiopulmonary Resuscitation in a Porcine Model

Background: Current guidelines for cardiopulmonary resuscitation (CPR) emphasize reducing pauses in chest compressions, and suggest ventilating with 1 second inspiration time and with enough volume to produce normal chest rise 10 times per minute. No specific advice is provided on how ventilations should be timed with ongoing chest compressions. We have compared hemodynamic effects of ventilating synchronously vs. asynchronously during chest compressions in a porcine model. Methods: Twenty anaesthetized domestic pigs (approx. 30 kg) were randomized into two groups; synchronous vs. asynchronous ventilation. Ventricular fibrillation is induced electrically and left for 2 minutes before initiation of basic 30:2 CPR for 4 minutes. CPR with continuous mechanical chest compressions was continued for another 8 minutes with either synchronous or asynchronous ventilation before defibrillation was attempted. Aortic, right atrial and intracerebral pressures, carotid and cerebral blood flow and cardiac output (thermodilution) were measured. Airway monitoring included capnography and spirometry. Results: Hemodynamics, blood gas analysis and airway pressures were similar for both groups during baseline and 30:2 CPR periods. The asynchronous group had higher median peak inspiratory airway pressure (94 vs. 57 cm H 2 O, p<0.001) and lower EtCO 2 (1.8 vs. 3.5 kPa, p=0.023) compared to synchronous group during the last 30 seconds of CPR (after 12 minutes). Asynchronous group also had higher pH (7.55 vs. 7.35, p<0.001), lower pCO 2 (2.4 vs. 4.7, p<0.001) and higher pO 2 (62.1 vs. 29.4, p<0.001) compared to synchronous group. There were no significant differences in any of the measured hemodynamic variables between the two groups with similar coronary and cerebral perfusion pressures. ROSC was achieved in 5/10 vs. 3/10 animals in the synchronous and asynchronous groups, respectively. Conclusion: Synchronous and asynchronous ventilation during mechanical chest compressions provide similar hemodynamics, but guideline-compliant asynchronous ventilation yields significantly higher airway pressures and hyperventilation. Implications for lung injury need to be assessed.

Percutaneous noncoronary interventions during continuous mechanical chest compression with the LUCAS-2 device

To compare the effect of different fragmentation softening grids in femtosecond laser-assisted cataract surgery on effective phacoemulsification time (EPT).

Continuous Mechanical Chest Compression Using the LUCAS-2 Device as a Bridge to Emergency Aortic Valve Surgery

A 44-year-old woman diagnosed with infective endocarditis was transferred to a tertiary-level hospital for further evaluation and treatment. During transport, she was fully conscious, hemodynamically stable, and spontaneously breathing with supplied nasal oxygen. On arrival at the tertiary hospital, she suffered asystolic cardiac arrest while being transferred from a stretcher to a bed. Immediate cardiopulmonary resuscitation (CPR) was initiated with manual chest compressions. Advanced cardiac life support was continued for 10 minutes using the algorithm of nonshockable rhythms.

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.

A randomized comparison of cardiocerebral and cardiopulmonary resuscitation using a swine model of prolonged ventricular fibrillation

Background Cardiocerebral resuscitation (CCR) is reportedly superior to cardiopulmonary resuscitation (CPR) for primary cardiac arrest in the prehospital setting. This study was done using a swine model of prolonged ventricular fibrillation (VF) to quantify the effect of the emergency medical services component of CCR with intraosseous access (CCR-IO) compared with standard CPR with intravenous access (CPR-IV) as it is typically performed during out-of-hospital cardiac arrest (OHCA) resuscitation in a prospective randomized fashion. Methods Fifty-three animals were instrumented under anesthesia and VF was electrically induced. After 10 min of untreated VF, baseline characteristics were recorded, and animals were block randomized to one of two resuscitation schemes. The controls had mechanical chest compressions at 100/min with ventilations at a ratio of 30:2. Consistent with clinical practice, two 30-s pauses in chest compressions occurred to simulate attempts to accomplish endotracheal intubation at minutes 1 and 3 of CPR and successful IV access was simulated to occur three additional minutes after endotracheal intubation. The CCR group had continuous uninterrupted mechanical chest compressions at 100/min. No active ventilations were provided. A tibial IO needle was placed in real time for vascular access. Both groups received epinephrine (0.1 mg/kg) as soon as access became available followed by 2.5 min of chest compressions before the first 120J rescue shock attempt. After successful rescue shock, standardized post-resuscitative care was provided to a 20-min endpoint. Failed rescue shock was followed by continued chest compressions with positive pressure ventilation in both groups, repeat doses of epinephrine (0.01 mg/kg) every 3 min, and rescue shock every minute as long as a shockable rhythm persisted. Group comparisons were assessed using descriptive statistics. Proportions with 95% confidence intervals were calculated for VF termination, ROSC, and survival. Results Baseline characteristics and chemistries between the two groups at VF induction and after 10 min of non-treatment were mathematically the same. The proportions of VF termination (0.50 vs. 0.82), ROSC (0.30 vs. 0.59), and 20-min survival (0.19 vs. 0.40) all strongly favored the CCR-IO group. Conclusion In this swine model of witnessed VF arrest with no bystander-initiated resuscitation, CCR-IO resulted in substantial improvement in all three outcomes relative to typical emergency medical services provided CPR-IV.

Experimental and clinical use of ongoing mechanical cardiopulmonary resuscitation during angiography and percutaneous coronary intervention

Coronary heart disease is the most frequent cause of cardiac arrest. Return of spontaneous circulation is often not achieved during resuscitation due to the inability to restore coronary blood flow. To review the literature with the aim of documenting if coronary angiography and subsequent percutaneous coronary intervention is feasible during continuous mechanical chest compressions. One experimental pig study, some case reports (of different size), and one recent abstract have documented the use of continuous mechanical chest compressions with the Lund University Cardiac Arrest System during angiographic procedures and subsequent percutaneous coronary intervention during cardiac arrest. If the arrest occurs in-hospital, especially during the angiographic procedure, the potential for successful outcome seems to be better. Coronary angiography and percutaneous coronary intervention is feasible during continuous mechanical chest compressions. This could be an alternative approach in cardiac arrest patients with suspected myocardial infarction who do not achieve return of spontaneous circulation with traditional resuscitation techniques.

Prearrest administration of low-molecular-weight heparin in porcine cardiac arrest: Hemodynamic effects and resuscitability*

Both animal and human studies demonstrate activation of coagulation during cardiac arrest. Prearrest anticoagulation is used routinely in many experimental studies. We studied the hemodynamic effects of prearrest anticoagulation with a low-molecular-weight heparin suitable for clinical use during cardiopulmonary resuscitation in pigs. Randomized and blinded experimental animal study. University hospital-affiliated research laboratory. Sixteen female domestic pigs. Three minutes before electrically induced ventricular fibrillation, enoxaparin 1 mg/kg or physiologic saline was blinded and administered intravenously. After 10 mins of untreated ventricular fibrillation, advanced cardiac life support was initiated with continuous mechanical chest compressions and interposed manual ventilation with 100% oxygen. Epinephrine was administered after 2 mins of advanced cardiac life support followed by attempted defibrillation 1 min thereafter. Advanced cardiac life support was continued for 10 mins following international guidelines. Electrocardiogram was recorded continuously and ventricular fibrillation waveform was analyzed (median slope). Animals with return of spontaneous circulation were observed for ten more minutes. Blood specimens were drawn for analysis of coagulation activation (thrombin-antithrombin complex) and drug effect (anti-factor Xa activity). Six of eight (75%) pigs in each group achieved return of spontaneous circulation. Thrombin-antithrombin complex levels were significantly lower in pigs that received enoxaparin. There was no significant difference either in measured hemodynamics between the groups during advanced cardiac life support and after return of spontaneous circulation or in median slope values during ventricular fibrillation. Epinephrine caused a significant decrease in femoral and increase in cerebral cortical blood flow with no difference between the groups. Prearrest anticoagulation with enoxaparin did not influence either hemodynamics during advanced cardiac life support and after return of spontaneous circulation or the frequency of return of spontaneous circulation in porcine cardiac arrest.

Cardiac arrest with continuous mechanical chest compression during percutaneous coronary intervention: A report on the use of the LUCAS device

Mechanical chest compression may be necessary to make coronary intervention possible during resuscitation. We report our experience using the Lund University Cardiac Arrest System (LUCAS, Jolife, Lund, Sweden) which is a gas-driven sternal compression device that incorporates a suction cup for active decompression. During the last 13 months LUCAS has been used in our catheterisation laboratory to maintain adequate organ perfusion pressure in 13 patients with cardiac arrest or severe hypotension and bradycardia (male/female ratio 1.6, mean age 59+/-19). The mean compression time was 105+/-60min (range 45-240), and the mean systolic and diastolic blood pressure obtained was 81+/-23 and 34+/-21mmHg, respectively. Angiography and eventually percutanous coronary intervention was possible in all cases during ongoing automatic chest compression. Three patients survived the procedure, but no patients were discharged alive. In two cases we found inadequate flow in the anterior descending artery, and in one case the invasive measurements revealed inadequate coronary perfusion pressure. There were no excessive intra-thoracic or intra-abdominal injuries. We conclude that the LUCAS device is suitable during cardiac catheterisation and intervention, and the device ensures an adequate systemic blood pressure in most patients without life-threatening injuries.

Haemodynamic effects of adrenaline (epinephrine) depend on chest compression quality during cardiopulmonary resuscitation in pigs

Adrenaline (epinephrine) is used during cardiopulmonary resuscitation (CPR) based on animal experiments without supportive clinical data. Clinically CPR was reported recently to have much poorer quality than expected from international guidelines and what is generally done in laboratory experiments. We have studied the haemodynamic effects of adrenaline during CPR with good laboratory quality and with quality simulating clinical findings and the feasibility of monitoring these effects through VF waveform analysis. After 4 min of cardiac arrest, followed by 4 min of basic life support, 14 pigs were randomised to ClinicalCPR (intermittent manual chest compressions, compression-to-ventilation ratio 15:2, compression depth 30-38 mm) or LabCPR (continuous mechanical chest compressions, 12 ventilations/min, compression depth 45 mm). Adrenaline 0.02 mg/kg was administered 30 s thereafter. Plasma adrenaline concentration peaked earlier with LabCPR than with ClinicalCPR, median (range), 90 (30, 150) versus 150 (90, 270) s (p = 0.007), respectively. Coronary perfusion pressure (CPP) and cortical cerebral blood flow (CCBF) increased and femoral blood flow (FBF) decreased after adrenaline during LabCPR (mean differences (95% CI) CPP 17 (6, 29) mmHg (p = 0.01), FBF -5.0 (-8.8, -1.2) ml min(-1) (p = 0.02) and median difference CCBF 12% of baseline (p = 0.04)). There were no significant effects during ClinicalCPR (mean differences (95% CI) CPP 4.7 (-3.2, 13) mmHg (p = 0.2), FBF -0.2 (-4.6, 4.2) ml min(-1)(p = 0.9) and CCBF 3.6 (-1.8, 9.0)% of baseline (p = 0.15)). Slope VF waveform analysis reflected changes in CPP. Adrenaline improved haemodynamics during laboratory quality CPR in pigs, but not with quality simulating clinically reported CPR performance.