Impact of personal protective equipment on the effectiveness of chest compression - A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

To assess the impact of personal protective equipment (PPE) on different aspects of chest compression (CC) during cardiopulmonary resuscitation, we conducted this study.

METHODS

This systematic review was performed according to the PRISMA. We searched PubMed, EMBASE and Web of Science from inception to June-6, 2020, limiting to the studies that reported the comparison of the effectiveness of CC in terms of CC rate, CC depth, the proportion of adequate CC rate, the proportion of adequate CC depth or proportion of adequate recoil; in study arms with or without PPE. Risk of bias was assessed by the ROB-2 and ROBINS-I tool. Quantitative data synthesis was done using the generic inverse variance method and the fixed-effects model.

RESULTS

Five simulation-based studies were finally included. A Significant decrease in CC rate (SMD: -0.28, 95%CI: -0.47 to -0.10) and CC depth (SMD: -0.26, 95%CI: -0.44 to -0.07) were observed in the PPE arm as compared to the no-PPE arm. The difference in CC rate was more prominently seen in adult CPR than in paediatric CPR. Without PPE, the proportion of adequate CC rate delivered was 0.74, which reduced significantly to 0.60 after use of PPE (p - 0.035). Similarly, the proportion of adequate CC depth was significantly lesser (p - 0.001) in PPE arm (0.55), as compared to that of the no-PPE arm (0.78).

CONCLUSION

The use of PPE compromises the quality of CC during CPR significantly, and newer ways to deliver chest compression has to be investigated. This study was prospectively registered in PROSPERO (CRD42020192031).

Cardiac Arrest in the Cardiac Catheterization Laboratory: Combining Mechanical Chest Compressions and Percutaneous LV Assistance

OBJECTIVES

The aim of this study was to evaluate the optimal treatment approach for cardiac arrest (CA) occurring in the cardiac catheterization laboratory.

BACKGROUND

CA can occur in the cath lab during high-risk percutaneous coronary intervention. While attempting to correct the precipitating cause of CA, several options are available to maintain vital organ perfusion. These include manual chest compressions, mechanical chest compressions, or a percutaneous left ventricular assist device.

METHODS

Eighty swine (58 ± 10 kg) were studied. The left main or proximal left anterior descending artery was occluded. Ventricular fibrillation (VFCA) was induced and circulatory support was provided with 1 of 4 techniques: either manual chest compressions (frequently interrupted), mechanical chest compressions with a piston device (LUCAS-2), an Impella 2.5 L percutaneously placed LVAD, or the combination of mechanical chest compressions and the percutaneous left ventricular assist device. The study protocol included 12 min of left main coronary occlusion, reperfusion, with defibrillation attempted after 15 min of VFCA. Primary outcome was favorable neurological function (CPC 1 or 2) at 24 h, while secondary outcomes included return of spontaneous circulation and hemodynamics.

RESULTS

Manual chest compressions provided fewer neurologically intact surviving animals than the combination of a mechanical chest compressor and a percutaneous LVAD device (0% vs. 56%; p < 0.01), while no difference was found between the 2 mechanical approaches (28% vs. 35%: p = 0.75). Comparing integrated coronary perfusion pressure showed sequential improvement in hemodynamic support with mechanical devices (401 ± 230 vs. 1,337 ± 905 mm Hg/s; p = 0.06).

CONCLUSIONS

Combining 2 mechanical devices provided superior 24-h survival with favorable neurological recovery compared with manual compressions during moderate duration VFCA associated with an acute coronary occlusion in the animal catheterization laboratory.

Comparison of in-hospital use of mechanical chest compression devices for out-of-hospital cardiac arrest patients: AUTOPULSE vs LUCAS

This study aimed to investigate the prognostic difference between AUTOPULSE and LUCAS for out-of-hospital cardiac arrest (OHCA) adult patients.A retrospective observational study was performed nationwide. Adult OHCA patients after receiving in-hospital mechanical chest compression from 2012 to 2016 were included. The primary outcomes were sustained return of spontaneous circulation (ROSC) of more than 20 minutes and survival to discharge.Among 142,906 OHCA patients, 820 patients were finally included. In multivariate analysis, female (OR, 0.57; 95% CI, 0.33-0.99), witnessed arrest (OR, 2.10; 95% CI, 1.20-3.69), and arrest cause of non-cardiac origin (OR, 0.25; 95% CI, 0.10-0.62) were significantly associated with the increase in ROSC. LUCAS showed a lower survival than AUTOPULSE (OR, 0.23; 95% CI, 0.06-0.84), although it showed no significant association with ROSC. Percutaneous coronary intervention (OR, 6.30; 95% CI, 1.53-25.95) and target temperature management (TTM; OR, 7.30; 95% CI, 2.27-23.49) were the independent factors for survival. We categorized mechanical CPR recipients by witness to compare prognostic effectiveness of AUTOPULSE and LUCAS. In the witnessed subgroup, female (OR, 0.46; 95% CI, 0.24-0.89) was a prognostic factor for ROSC and shockable rhythm (OR, 5.04; 95% CI, 1.00-25.30), percutaneous coronary intervention (OR, 12.42; 95% CI, 2.04-75.53), and TTM (OR, 9.03; 95% CI, 1.86-43.78) for survival. In the unwitnessed subgroup, no prognostic factors were found for ROSC, and TTM (OR, 99.00; 95% CI, 8.9-1100.62) was found to be an independent factor for survival. LUCAS showed no significant increase in ROSC or survival in comparison with AUTOPULSE in both subgroups.The in-hospital use of LUCAS may have a deleterious effect for survival compared with AUTOPULSE.

The TrueCPR device in the process of teaching cardiopulmonary resuscitation: A randomized simulation trial

BACKGROUND

International resuscitation guidelines emphasize the importance of high quality chest compressions, including correct chest compression depth and rate and complete chest recoil. The aim of the study was to assess the role of the TrueCPR device in the process of teaching cardiopulmonary resuscitation in nursing students.

METHODS

A prospective randomized experimental study was performed among 94 first year students of nursing. On the next day, the participants were divided into 2 groups-the control group practiced chest compressions without the use of any device for half an hour, and the experimental group practiced with the use of TrueCPR. Further measurement of chest compressions was performed after a month.

RESULTS

The chest compression rate achieved the value of 113 versus 126 (P < .001), adequate chest compression rate (%) was 86 versus 68 (P < .001), full chest release (%) 92 versus 69 (P = .001), and correct hand placement (%) 99 versus 99 (P, not significant) in TrueCPR and standard BLS groups, respectively. As for the assessment of the confidence of chest compression quality, 1 month after the training, the evaluation in the experimental group was statistically significantly higher (91 vs 71; P < .001) than in the control group.

CONCLUSIONS

Cardiopulmonary resuscitation training with the use of the TrueCPR device is associated with better resuscitation skills 1 month after the training. The participants using TrueCPR during the training achieved a better chest compression rate and depth with in international recommendations and better full chest release percentage and self-assessed confidence of chest compression quality comparing with standard cardiopulmonary resuscitation training.

Mechanical versus manual chest compressions in the treatment of in-hospital cardiac arrest patients in a non-shockable rhythm: a randomised controlled feasibility trial (COMPRESS-RCT)

BACKGROUND

Mechanical chest compression devices consistently deliver high-quality chest compressions. Small very low-quality studies suggest mechanical devices may be effective as an alternative to manual chest compressions in the treatment of adult in-hospital cardiac arrest patients. The aim of this feasibility trial is to assess the feasibility of conducting an effectiveness trial in this patient population.

METHODS

COMPRESS-RCT is a multi-centre parallel group feasibility randomised controlled trial, designed to assess the feasibility of undertaking an effectiveness to compare the effect of mechanical chest compressions with manual chest compressions on 30-day survival following in-hospital cardiac arrest. Over approximately two years, 330 adult patients who sustain an in-hospital cardiac arrest and are in a non-shockable rhythm will be randomised in a 3:1 ratio to receive ongoing treatment with a mechanical chest compression device (LUCAS 2/3, Jolife AB/Stryker, Lund, Sweden) or continued manual chest compressions. It is intended that recruitment will occur on a 24/7 basis by the clinical cardiac arrest team. The primary study outcome is the proportion of eligible participants randomised in the study during site operational recruitment hours. Participants will be enrolled using a model of deferred consent, with consent for follow-up sought from patients or their consultee in those that survive the cardiac arrest event. The trial will have an embedded qualitative study, in which we will conduct semi-structured interviews with hospital staff to explore facilitators and barriers to study recruitment.

DISCUSSION

The findings of COMPRESS-RCT will provide important information about the deliverability of an effectiveness trial to evaluate the effect on 30-day mortality of routine use of mechanical chest compression devices in adult in-hospital cardiac arrest patients.

TRIAL REGISTRATION

ISRCTN38139840 , date of registration 9th January 2017.

Mechanical versus manual chest compressions for cardiac arrest

BACKGROUND

Mechanical chest compression devices have been proposed to improve the effectiveness of cardiopulmonary resuscitation (CPR).

OBJECTIVES

To assess the effectiveness of resuscitation strategies using mechanical chest compressions versus resuscitation strategies using standard manual chest compressions with respect to neurologically intact survival in patients who suffer cardiac arrest.

SEARCH METHODS

On 19 August 2017 we searched the Cochrane Central Register of Controlled Studies (CENTRAL), MEDLINE, Embase, Science Citation Index-Expanded (SCI-EXPANDED) and Conference Proceedings Citation Index-Science databases. Biotechnology and Bioengineering Abstracts and Science Citation abstracts had been searched up to November 2009 for prior versions of this review. We also searched two clinical trials registries for any ongoing trials not captured by our search of databases containing published works: Clinicaltrials.gov (August 2017) and the World Health Organization International Clinical Trials Registry Platform portal (January 2018). We applied no language restrictions. We contacted experts in the field of mechanical chest compression devices and manufacturers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster-RCTs and quasi-randomised studies comparing mechanical chest compressions versus manual chest compressions during CPR for patients with cardiac arrest.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included five new studies in this update. In total, we included 11 trials in the review, including data from 12,944 adult participants, who suffered either out-of-hospital cardiac arrest (OHCA) or in-hospital cardiac arrest (IHCA). We excluded studies explicitly including patients with cardiac arrest caused by trauma, drowning, hypothermia and toxic substances. These conditions are routinely excluded from cardiac arrest intervention studies because they have a different underlying pathophysiology, require a variety of interventions specific to the underlying condition and are known to have a prognosis different from that of cardiac arrest with no obvious cause. The exclusions were meant to reduce heterogeneity in the population while maintaining generalisability to most patients with sudden cardiac death.The overall quality of evidence for the outcomes of included studies was moderate to low due to considerable risk of bias. Three studies (N = 7587) reported on the designated primary outcome of survival to hospital discharge with good neurologic function (defined as a Cerebral Performance Category (CPC) score of one or two), which had moderate quality evidence. One study showed no difference with mechanical chest compressions (risk ratio (RR) 1.07, 95% confidence interval (CI) 0.82 to 1.39), one study demonstrated equivalence (RR 0.79, 95% CI 0.60 to 1.04), and one study demonstrated reduced survival (RR 0.41, CI 0.21 to 0.79). Two other secondary outcomes, survival to hospital admission (N = 7224) and survival to hospital discharge (N = 8067), also had moderate quality level of evidence. No studies reported a difference in survival to hospital admission. For survival to hospital discharge, two studies showed benefit, four studies showed no difference, and one study showed harm associated with mechanical compressions. No studies demonstrated a difference in adverse events or injury patterns between comparison groups but the quality of data was low. Marked clinical and statistical heterogeneity between studies precluded any pooled estimates of effect.

AUTHORS' CONCLUSIONS

The evidence does not suggest that CPR protocols involving mechanical chest compression devices are superior to conventional therapy involving manual chest compressions only. We conclude on the balance of evidence that mechanical chest compression devices used by trained individuals are a reasonable alternative to manual chest compressions in settings where consistent, high-quality manual chest compressions are not possible or dangerous for the provider (eg, limited rescuers available, prolonged CPR, during hypothermic cardiac arrest, in a moving ambulance, in the angiography suite, during preparation for extracorporeal CPR [ECPR], etc.). Systems choosing to incorporate mechanical chest compression devices should be closely monitored because some data identified in this review suggested harm. Special attention should be paid to minimising time without compressions and delays to defibrillation during device deployment.

Efficacy and safety of mechanical versus manual compression in cardiac arrest - A Bayesian network meta-analysis

AIM

To compare relative efficacy and safety of mechanical compression devices (AutoPulse and LUCAS) with manual compression in patients with cardiac arrest undergoing cardiopulmonary resuscitation (CPR).

METHODS

For this Bayesian network meta-analysis, seven randomized controlled trials (RCTs) were selected using PubMed/Medline, EMBASE, and CENTRAL (Inception- 31 October 2017). For all the outcomes, median estimate of odds ratio (OR) from the posterior distribution with corresponding 95% credible interval (Cr I) was calculated. Markov chain Monte Carlo (MCMC) modeling was used to estimate the relative ranking probability of each intervention based on surface under the cumulative ranking curve (SUCRA).

RESULTS

In analysis of 12, 908 patients with cardiac arrest [AutoPulse (2, 608 patients); LUCAS (3, 308 patients) and manual compression (6, 992 patients)], manual compression improved survival at 30 days or hospital discharge (OR, 1.40, 95% Cr I, 1.09-1.94), and neurological recovery (OR, 1.51, 95% Cr I, 1.06-2.39) compared to AutoPulse. There were no differences between LUCAS and AutoPulse with regards to survival to hospital admission, neurological recovery or return of spontaneous circulation (ROSC). Manual compression reduced the risk of pneumothorax (OR, 0.56, 95% Cr I, 0.33-0.97); while, both manual compression (OR, 0.15, 95% Cr I, 0.01-0.73) and LUCAS (OR, 0.07, 95% Cr I, 0.00-0.43) reduced the risk of hematoma formation compared to AutoPulse. Probability analysis ranked manual compression as the most effective treatment for improving survival at 30 days or hospital discharge (SUCRA, 84%).

CONCLUSIONS

Manual compression is more effective than AutoPulse and comparable to LUCAS in improving survival at 30 days or hospital discharge and neurological recovery. Manual compression had lesser risk of pneumothorax or hematoma formation compared to AutoPulse.

Training approaches for the deployment of a mechanical chest compression device: a randomised controlled manikin study

OBJECTIVES

To evaluate the effect of training strategy on team deployment of a mechanical chest compression device.

DESIGN

Randomised controlled manikin trial.

SETTING

Large teaching hospital in the UK.

PARTICIPANTS

Twenty teams, each comprising three clinicians. Participating individuals were health professionals with intermediate or advanced resuscitation training.

INTERVENTIONS

Teams were randomised in a 1:1 ratio to receive either standard mechanical chest compression device training or pit-crew device training. Training interventions lasted up to 1 h. Performance was measured immediately after training in a standardised simulated cardiac arrest scenario in which teams were required to deploy a mechanical chest compression device.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome was chest compression flow fraction in the minute preceding the first mechanical chest compression. Secondary outcomes included cardiopulmonary resuscitation quality and mechanical device deployment metrics, and non-technical skill performance. Outcomes were assessed using video recordings of the test scenario.

RESULTS

In relation to the primary outcome of chest compression flow fraction in the minute preceding the first mechanical chest compression, we found that pit-crew training was not superior to standard training (0.76 (95% CI 0.73 to 0.79) vs 0.77 (95% CI 0.73 to 0.82), mean difference -0.01 (95% CI -0.06 to 0.03), P=0.572). There was also no difference between groups in performance in relation to any secondary outcome.

CONCLUSIONS

Pit-crew training, compared with standard training, did not improve team deployment of a mechanical chest device in a simulated cardiac arrest scenario.

TRIAL REGISTRATION NUMBER

ISRCTN43049287; Pre-results.

Use of automated chest compression devices after out-of-hospital cardiac arrest in Sweden

OBJECTIVE

To evaluate the implementation of automated chest compression cardiopulmonary resuscitation (ACC-CPR) after out-of-hospital cardiac arrest (OHCA) in Sweden during the years 2011 through 2015. The association between ACC-CPR and 30-day survival was studied as a secondary objective.

METHODS

The Swedish cardiopulmonary resuscitation registry is a prospectively recorded nationwide registry of modified Utstein parameters including all patients with attempted resuscitation after OHCA. Propensity score matching (PSM) was used to adjust for known confounders in the secondary analysis.

RESULTS

Of the 24,316 patients included in the study population, 32.4% received ACC-CPR, with substantial regional variation ranging from 0.8% to 78.8%. Male gender and an initial shockable rhythm were associated with ACC-CPR, whereas crew witnessed status was associated with manual CPR. Potential markers of prolonged resuscitation attempts (drug administration and endotracheal intubation) were more prevalent in the ACC-CPR group. The unadjusted 30-day survival rate was 6.3% for ACC-CPR patients. The adjusted odds ratio for 30-day survival regarding use of an ACC device was 0.72 (95% CI 0.62-0.84, p<0.001, n=13922).

CONCLUSION

The use of ACC devices varied significantly between Swedish regions and overall survival to 30days was low among patients receiving ACC-CPR. Although measured and unmeasured confounding might explain our finding of lower survival rates for patients exposed to ACC-CPR, specific guidelines recommending when and how ACC-CPR should be used are warranted as there might be circumstances where these devices do more harm than good.

Mechanical compression devices for cardiac arrest: report of three cases

Mechanical compression devices enable transportation of patients with cardiac arrest to the catheterization laboratory. Coronary angiography and coronary interventions can be performed while the patients are being resuscitated with these devices. In this report, we describe three cases in whom resuscitation with mechanical compression devices and rapid transportation to the catheterization laboratory resulted in favorable cardiac and neurological outcome.

LUCAS(™)2 in Danish Search and Rescue Helicopters

OBJECTIVE

Prehospital resuscitation is often challenging. Giving uninterrupted and effective compressions is relatively impossible during transportation. In 2012, The Royal Danish Air Force received a donation of 8 mechanical chest compression devices (LUCAS(™)2; Physio-Control/Jolife AB, Lund, Sweden) to be used onboard the Danish search and rescue (SAR) helicopters. The scope of this investigation was to establish whether or not mechanical chest compression devices should be considered a necessity onboard the Danish SAR helicopters.

METHODS

Data were compiled from SAR medical journals. From the data collected, observations were made as to when LUCAS(™)2 was used and what diagnosis the SAR physician made.

RESULTS

One thousand ninety missions were registered in the 24-month research period, and LUCAS(™)2 was used in 25 missions. Cardiac emergencies amounted for 25% of the missions.

CONCLUSION

The Danish SAR helicopters retrieved 33 drowned/hypothermic patients during the research period, and the LUCAS(™)2 was used in 11 of the patients requiring resuscitation. The LUCAS(™)2 was frequently used during other emergencies like sudden cardiac arrest. Cardiac emergencies were the predominant type of mission. LUCAS(™)2 is now considered mandatory on Danish SAR helicopters.

[Transluminal coronary angioplasty during resuscitation--an option not to be ignored]

We describe a prolonged and successful in-hospital resuscitation, during which the cause of cardiac arrest was treated by transluminal coronary angioplasty. A closed cardiac massage device was used in the resuscitation of the patient, and the treatment required close collaboration between the cardiologist and the resuscitation team. In spite of the difficult initial situation and several disturbances of vital functions the patient was discharged in good condition.

Accurate feedback of chest compression depth on a manikin on a soft surface with correction for total body displacement

OBJECTIVE

TrueCPR is a new real-time compression depth feedback device that measures changes in magnetic field strength between a back pad and a chest pad. We determined its accuracy with a manikin on a test bench and on various surfaces.

METHODS

First, calibration and accuracy of the manikin and TrueCPR was verified on a drill press. Then, manual chest compressions were given, on a firm surface and on a foam or air mattress, with feedback of the TrueCPR or Q-CPR accelerometer, to achieve a depth of 50mm. Compression depth measurements by the devices and the manikin were compared.

RESULTS

On a hard surface TrueCPR showed a systematic underestimation of 2-3mm in the drill press. Manual tests on a hard surface showed a slightly larger underestimation of 4.5mm. When guided by TrueCPR on a foam or air mattress, the TrueCPR measured a mean(±SD) chest compression depth of 52.0(±1.9)mm and 49.4(±2.6)mm respectively, while the manikin measured 54.4(±1.8)mm and 52.1(±1.4)mm, respectively (p<0.001). When guided by the Q-CPR accelerometer on a foam or air mattress, the accelerometer measured depth of 54.3(±3.6)mm and 56.0(±3.8)mm respectively, compared to the manikin 42.4(±2.3)mm and 34.9(±3.6)mm, respectively (p<0.001).

CONCLUSION

TrueCPR measures depth precisely, independent of the stiffness of the surface upon which the CPR is being performed with a constant inaccuracy of <4.5mm. A sternum-only accelerometer substantially overestimates depth when performing CPR on a soft surface. Correction for body displacement on a soft surface is essential for accurate delivery of chest compressions within the recommended depth range.

Mechanical versus manual chest compressions for cardiac arrest

BACKGROUND

This is the first update of the Cochrane review on mechanical chest compression devices published in 2011 (Brooks 2011). Mechanical chest compression devices have been proposed to improve the effectiveness of cardiopulmonary resuscitation (CPR).

OBJECTIVES

To assess the effectiveness of mechanical chest compressions versus standard manual chest compressions with respect to neurologically intact survival in patients who suffer cardiac arrest.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Studies (CENTRAL; 2013, Issue 12), MEDLINE Ovid (1946 to 2013 January Week 1), EMBASE (1980 to 2013 January Week 2), Science Citation abstracts (1960 to 18 November 2009), Science Citation Index-Expanded (SCI-EXPANDED) (1970 to 11 January 2013) on Thomson Reuters Web of Science, biotechnology and bioengineering abstracts (1982 to 18 November 2009), conference proceedings Citation Index-Science (CPCI-S) (1990 to 11 January 2013) and clinicaltrials.gov (2 August 2013). We applied no language restrictions. Experts in the field of mechanical chest compression devices and manufacturers were contacted.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster RCTs and quasi-randomised studies comparing mechanical chest compressions versus manual chest compressions during CPR for patients with atraumatic cardiac arrest.

DATA COLLECTION AND ANALYSIS

Two review authors abstracted data independently; disagreement between review authors was resolved by consensus and by a third review author if consensus could not be reached. The methodologies of selected studies were evaluated by a single author for risk of bias. The primary outcome was survival to hospital discharge with good neurological outcome. We planned to use RevMan 5 (Version 5.2. The Nordic Cochrane Centre) and the DerSimonian & Laird method (random-effects model) to provide a pooled estimate for risk ratio (RR) with 95% confidence intervals (95% CIs), if data allowed.

MAIN RESULTS

Two new studies were included in this update. Six trials in total, including data from 1166 participants, were included in the review. The overall quality of included studies was poor, and significant clinical heterogeneity was observed. Only one study (N = 767) reported survival to hospital discharge with good neurological function (defined as a Cerebral Performance Category score of one or two), demonstrating reduced survival with mechanical chest compressions when compared with manual chest compressions (RR 0.41, 95% CI 0.21 to 0.79). Data from four studies demonstrated increased return of spontaneous circulation, and data from two studies demonstrated increased survival to hospital admission with mechanical chest compressions as compared with manual chest compressions, but none of the individual estimates reached statistical significance. Marked clinical heterogeneity between studies precluded any pooled estimates of effect.

AUTHORS' CONCLUSIONS

Evidence from RCTs in humans is insufficient to conclude that mechanical chest compressions during cardiopulmonary resuscitation for cardiac arrest are associated with benefit or harm. Widespread use of mechanical devices for chest compressions during cardiac events is not supported by this review. More RCTs that measure and account for the CPR process in both arms are needed to clarify the potential benefit to be derived from this intervention.

Active chest compression-decompression for cardiopulmonary resuscitation

BACKGROUND

Active compression-decompression cardiopulmonary resuscitation (ACDR CPR) uses a hand-held suction device, applied mid-sternum, to compress the chest then actively decompress the chest after each compression. Randomised controlled trials testing this device have shown discordant results.

OBJECTIVES

To determine the effect of active chest compression-decompression CPR compared to standard chest compression CPR on mortality and neurological function in adults with cardiac arrest treated either in-hospital or out-of-hospital.

SEARCH METHODS

We updated the searches of CENTRAL in The Cochrane Library (Issue 12 of 12, 2012), MEDLINE (OVID, 1946 to January week 1 2013), and EMBASE (OVID, 1980 to week 1 2013) on 14 January 2013. We checked the reference list of retrieved articles, contacted experts in the field, and searched ClinicalTrials.gov.

SELECTION CRITERIA

All randomised or quasi-randomised studies comparing active compression-decompression with standard manual chest compression in adults with a cardiac arrest who received cardiopulmonary resuscitation by a trained medical or paramedical team.

DATA COLLECTION AND ANALYSIS

We independently extracted data on an intention-to-treat basis. When needed, we contacted the authors of the primary studies. If appropriate, we cumulated studies and pooled relative risk (RR) estimates. We predefined subgroup analyses according to setting (out-of-hospital or in-hospital) and attending team composition (with physician or paramedic only).

MAIN RESULTS

In this update, 27 new related publications were found, but they did not all fulfil inclusion criteria or concerned participants already reported in previous publications. In the end, we included 10 trials in this review: Eight were in out-of-hospital settings; one was set in-hospital only; and one had both in-hospital and out-of-hospital components. Allocation concealment was adequate in four studies. The two in-hospital studies were different in quality and size (773 and 53 participants). Both found no differences between ACDR CPR and STR in any outcome.Out-of-hospital trials cumulated 4162 participants. There were no differences between ACDR CPR and STR for mortality either immediately (RR 0.98, 95% confidence interval (CI) 0.94 to 1.03) or at hospital discharge (RR 0.99, 95% CI 0.98 to 1.01). The pooled RR of neurological impairment of any severity was 1.71 (95% CI 0.90 to 3.25), with a non-significant trend to more frequent severe neurological damage in survivors of ACDR CPR (RR 3.11, 95% CI 0.98 to 9.83). However, assessment of neurological outcome was limited, and few participants had neurological damage.There was no difference between ACDR CPR and STR with regard to complications such as rib or sternal fractures, pneumothorax, or haemothorax (RR 1.09, 95% CI 0.86 to 1.38). Skin trauma and ecchymosis were more frequent with ACDR CPR.

AUTHORS' CONCLUSIONS

Active chest compression-decompression in people with cardiac arrest is not associated with any clear benefit.

[Acute pulmonary embolism and cardiac arrest treated with thrombolysis and an automatic chest compression device]

Survival after pulseless electrical activity cardiac arrest is poor. In this case report we describe a patient who had acute massive pulmonary embolism and was treated with thrombolysis and an automatic mechanical chest compression device, Lund University Cardiac Arrest System (LUCAS 2). Chest compressions were effectively provided for two hours during a prolonged resuscitation and transferral for pulmonary embolectomy. The patient was extubated one day after the operation and discharged with normal cerebral function nine days after the cardiac arrest.

Use of backboard and deflation improve quality of chest compression when cardiopulmonary resuscitation is performed on a typical air inflated mattress configuration

No study has examined the effectiveness of backboards and air deflation for achieving adequate chest compression (CC) depth on air mattresses with the typical configurations seen in intensive care units. To determine this efficacy, we measured mattress compression depth (MCD, mm) on these surfaces using dual accelerometers. Eight cardiopulmonary resuscitation providers performed CCs on manikins lying on 4 different surfaces using a visual feedback system. The surfaces were as follows: A, a bed frame; B, a deflated air mattress placed on top of a foam mattress laid on a bed frame; C, a typical air mattress configuration with an inflated air mattress placed on a foam mattress laid on a bed frame; and D, C with a backboard. Deflation of the air mattress decreased MCD significantly (B; 14.74 ± 1.36 vs C; 30.16 ± 3.96, P < 0.001). The use of a backboard also decreased MCD (C; 30.16 ± 3.96 vs D; 25.46 ± 2.89, P = 0.002). However, deflation of the air mattress decreased MCD more than use of a backboard (B; 14.74 ± 1.36 vs D; 25.46 ± 2.89, P = 0.002). The use of a both a backboard and a deflated air mattress in this configuration reduces MCD and thus helps achieve accurate CC depth during cardiopulmonary resuscitation.

[Automatic mechanical chest compression during helicopter transportation]

We describe a case story with a drowned, hypothermic trauma patient treated with an automatic mechanical chest compression device during helicopter transportation to a trauma center. After falling from a 25 meter high bridge into 2 °C water, she was rescued lifeless 17 minutes later. Advanced life support was initiated. During transport by a rescue helicopter, chest compressions were effectively provided by Lund University Cardiopulmonary Assist System (LUCAS). Upon arrival to a trauma centre approx. 60 minutes later, the patient was treated with extracorporal circulation and rewarmed. She was eventually discharged to her home with minor loss of cerebral function.

[Prolonged mechanical cardiopulmonary resuscitation]

Efficient cardiopulmonary resuscitation (CPR) contributes to improved outcome after cardiac arrest. New mechanical devices improve cardiac output. We present a case-report with a male patient who was admitted after 55 minutes of out-of-hospital CPR which was followed by 45 minutes of in-hospital CPR with a mechanical device (LUCAS). Cardiac arrest was due to severe electrolyte disorders with plasma potassium: 2.0 mmol/L and ionized calcium: 0.87 mmol/L. There were no signs of coronary artery disease. The patient was later discharged without neurological deficits. Adequate mechanical massage during CPR may improve survival. However, randomised clinical trials are warranted.

The optimal phasic relationship between synchronized shock and mechanical chest compressions

OBJECTIVE

Pauses for shock delivery in chest compressions are detrimental to the success of resuscitation and may be eliminated with the use of mechanical chest compressors. However, the optimal phasic relationship between mechanical chest compression and defibrillation is still unknown. We therefore undertook a study to assess the effects of timing of defibrillation in the mechanical chest compression cycle on the defibrillation threshold (DFT) using a porcine model of cardiac arrest.

METHODS

Ventricular fibrillation was electrically induced and untreated for 10s in 8 domestic pigs weighing between 26 and 30 kg. Mechanical chest compression was then continuously performed for 25s, followed by a biphasic electrical shock which was delivered to the animal at 6 randomized coupling phases, including a control phase, with a pre-determined energy setting. The control phase was chosen at a constant 2s following discontinued chest compression. A novel grouped up-and-down DFT testing protocol was used to compare the success rate at different coupling phases. After a recovery interval of 4 min, the testing sequence was repeated, resulting in a total of 60 test shocks delivered to each animal.

RESULTS

No difference between the delivered shock energy, voltage and current were observed among the 6 study phases. The defibrillation success rate, however, was significantly higher when shocks were delivered in the upstroke phase of mechanical chest compression.

CONCLUSION

Defibrillation efficacy is maximal when electrical shock is delivered in the upstroke phase of mechanical chest compression.

Use of an automated device for external chest compressions by first-aid workers unfamiliar with the device: a step toward public access?

OBJECTIVE

The objective was to establish the feasibility of using an automated external chest compression (ECC) device among first-aid workers unfamiliar with the device.

METHODS

Eighty first-aid workers unfamiliar with the Autopulse ECC device were randomized into three groups. Group 1 was given two explanatory illustrations on device use. Group 2 was given four explanatory illustrations. Group 3 was shown a 5-minute video on the placement and use of the device and allowed to handle the device for 5 minutes. The time taken to place and start the device on a mannequin was recorded.

RESULTS

There was no significant difference among the three groups with regard to age, sex ratio, experience, and time elapsed since their last training session. No mistakes in device placement were made by any of the groups. All 80 participants started ECC in less than 160 seconds. There was no significant difference between Groups 1 and 2 in time taken to place or start the device (medians and 25-75 percentiles = 72 [54-112] vs. 86 [46-130] seconds and 154 [103-183] vs. 156 [120-197] seconds, respectively). However, Group 3 first-aid workers obtained significantly better results (19 [16-26] seconds to place and 48 [40-65] seconds to start; p<0.0001).

CONCLUSIONS

An automated ECC device can be rapidly placed and used by first-aid workers unfamiliar with the device. In the light of these results, use of the device by the general public can be envisaged.

[Mechanical cardiac massage]

Continuous delivery of high-quality chest compressions is the most important and difficult part of resuscitation. Two automatic mechanical chest compression devices - LUCAS and Autopulse - have been implemented in Denmark in order to optimize the circulation in patients with cardiac arrest. In spite of some practical benefits, improved haemodynamics in animal models, and a possible increase in short-term survival, none of the devices improved the long-term survival or neurological outcome in patients with cardiac arrest. Future randomized trials are crucial.

The impact of compliant surfaces on in-hospital chest compressions: effects of common mattresses and a backboard

PURPOSE

To evaluate, in a hospital setting, the influence of different, common mattresses, with and without a backboard, on chest movement during CPR.

DESIGN AND SETTING

Sixty CPR sessions (140s each, 30:2, C:R ratio 1:1) were performed using a manikin on standard hospital mattresses, with or without a backboard in combination with variable weights. Sternum-to-spine compression distance was controlled (range 30-60mm) allowing evaluation of the underlying compliant surface on total hand travel.

RESULTS

Movement of the caregiver's hands was significantly larger (up to 111mm at 50mm compression depth, p<0.0001) when sternum-to-spine compressions were performed without a backboard than with one. The extent of this variable extra travel effect depended on the type of mattress as well as the force of compression. Foam mattresses and air chamber systems act as springs and follow hand movement, while 'slow foam' mattresses incorporate time delays, making depth and force sensing harder. A backboard decreases the extra hand movement due to mattress effects by more than 50%, strongly reducing caregiver work.

CONCLUSIONS

Total vertical hand movement is significantly, and clinically relevantly much, larger than sternum-to-spine compression depth when CPR is performed on a mattress. Additional movement depends on the type of mattress and can be strongly reduced, but not eliminated, when a backboard is applied. The additional motion and increased work load adds extra complexity to in-hospital CPR. We propose that this should be taken into account during training by in-hospital caregivers.

Cardiac arrest with continuous mechanical chest compression during percutaneous coronary intervention

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.

Compression force–depth relationship during out-of-hospital cardiopulmonary resuscitation

BACKGROUND

Recent clinical studies reporting the high frequency of inadequate chest compression depth (<38 mm) during CPR, have prompted the question if adult human chest characteristics render it difficult to attain the recommended compression depth in certain patients.

MATERIAL AND METHODS

Using a specially designed monitor/defibrillator equipped with a sternal pad fitted with an accelerometer and a pressure sensor, compression force and depth was measured during CPR in 91 adult out-of-hospital cardiac arrest patients.

RESULTS

There was a strong non-linear relationship between the force of compression and depth achieved. Mean applied force for all patients was 30.3+/-8.2 kg and mean absolute compression depth 42+/-8 mm. For 87 of 91 patients 38 mm compression depth was obtained with less than 50 kg. Stiffer chests were compressed more forcefully than softer chests (p<0.001), but softer chests were compressed more deeply than stiffer chests (p=0.001). The force needed to reach 38 mm compression depth (F38) and mean compression force were higher for males than for females: 29.8+/-14.5 kg versus 22.5+/-10.2 kg (p<0.02), and 32.0+/-8.3 kg versus 27.0+/-7.0 kg (p<0.01), respectively. There was no significant variation in F38 or compression depth with age, but a significant 1.5 kg mean decrease in applied force for each 10 years increase in age (p<0.05). Chest stiffness decreased significantly (p<0.0001) with an increasing number of compressions performed. Average residual force during decompression was 1.7+/-1.0 kg, corresponding to an average residual depth of 3+/-2 mm.

CONCLUSION

In most out-of-hospital cardiac arrest victims adequate chest compression depth can be achieved by a force<50 kg, indicating that an average sized and fit rescuer should be able to perform effective CPR in most adult patients.

CPREzy™ improves performance of external chest compressions in simulated cardiac arrest

AIM OF THE STUDY

External chest compression (ECC) is an essential part of cardiopulmonary resuscitation and usually performed without any adjuncts. Although different supportive devices have been developed, none have yet been implemented as a standard procedure to guide rescuers in resuscitation. This study investigates the effects of the CPREzy-pad on ECC performed by first year medical students during simulated cardiac arrest.

MATERIALS AND METHODS

Two hundred and two subjects were randomised and asked to perform 5 min of single-rescuer-CPR. Group 1 (n = 111) was taught classic ECC, followed by ECC with the CPREzy and was tested in ECC with the CPREzy. Group 2 (n = 91) was taught and tested in classic ECC only. One week later each group was divided: Group 1A was tested in ECC with the CPREzy again; Group 1B was tested in classic ECC. Group 2A was taught and tested in ECC with CPREzy; Group 2B was tested in classic ECC again. Primary endpoints were compression rate (90-110/min) and compression depth (40-50mm).

RESULTS

Comparing groups 1 and 2, ECC was significantly superior with CPREzy (correct rate: 93.7% versus 19.8%, p < or = 0.01; depth: 71.2% versus 34.1%, p < or = 0.01). The group tested with CPREzy initially 1 week later (2A; n = 36) improved significantly in correct compression rate (19.8% versus 88.9%, p < or = 0.01) and compression depth (34.1% versus 75.0%, p < or = 0.02). The control-group (2B; n = 55) without CPREzy demonstrated poor performance in both evaluations (correct rate: 19.8% versus 25.5%, depth: 34.1% versus 43.6%).

CONCLUSION

CPREzy as a simple portable and re-usable device is able to improve performance of ECC in simulated cardiac arrest.

Cardiac arrest and resuscitation with an automatic mechanical chest compression device (LUCAS) due to anaphylaxis of a woman receiving caesarean section because of pre-eclampsia

We report a case of anaphylaxis with pulseless electrical activity (PEA)(verified by ECG and a radial intra-arterial line) in a 30-year-old woman who received 3G Promiten (dextran-1) and a prophylactic intra-venous infusion of Macrodex (dextran) for postoperative thromboembolism during caesarean section for pre-eclampsia in the 24th week of gestation. Manual chest compressions, followed by mechanical chest compressions (LUCAS, Jolife, Lund, Sweden), were performed for 50min before restoration of spontaneous circulation (ROSC). She awoke the next day with no sequelae. She had some suction cup marks on the sternum but otherwise no complications of the chest compressions. At follow up by phone 1 month later, she and her baby were doing well.

A case of hypothermic cardiac arrest treated with an external chest compression device (LUCAS) during transport to re-warming

The recommended treatment for severe hypothermia with circulatory collapse is re-warming using cardiopulmonary by-pass. This may require transporting a patient to hospital with on-going cardiopulmonary resuscitation (CPR). Manual CPR during patient transport may result in sub-optimal chest compressions and can be a hazard for the ambulance crew. We report a case of a patient with a core temperature of 22.2 degrees C and crew-witnessed cardiac arrest due to hypothermia. After unsuccessful initial resuscitation he was transported to hospital for re-warming with cardiopulmonary by-pass. CPR was continued during transport using a mechanical active compression-decompression device (the LUCAS-device). During cardiopulmonary by-pass ROSC was achieved after 90 min of cardiac arrest. The patient recovered with a cerebral performance category of 3. Using a mechanical device for chest compressions during transport of a hypothermic patient with on-going CPR is feasible, effective and safe.

Treatment of out-of-hospital cardiac arrest with LUCAS, a new device for automatic mechanical compression and active decompression resuscitation

Lund University Cardiopulmonary Assist System (LUCAS) is a new gas-driven CPR device providing automatic chest compression and active decompression. This is a report of the first 100 consecutive cases treated with LUCAS due to out-of-hospital cardiac arrest (58% asystole, 42% ventricular fibrillation (VF)). Safety aspects were also investigated and it was found that LUCAS can be used safely regarding noise levels and oxygen concentrations within the ambulance. A crash test (10G) showed no displacement of the device from the manikin. Of the 71 patients with witnessed cardiac arrest, 39% received bystander CPR. In those 28 patients where LUCAS-CPR was initiated more than 15 min after the ambulance alarm and in the 29 unwitnessed cases, none survived for 30 days. Of the 43 witnessed cases treated with LUCAS within 15 min, 24 had VF and 15 (63%) of these cases achieved a stable return of spontaneous circulation (ROSC) and 6 (25%) of them survived with a good neurological recovery after 30 days; 5 (26%) of the 19 patients with asystole achieved ROSC and 1 (5%) survived for over 30 days. One patient where ROSC could not be achieved was transported with on-going LUCAS-CPR to the catheter laboratory and after PCI for an occluded LAD a stable ROSC occurred, but the patient never regained consciousness and died 15 days later. To conclude, establishment of an adequate cerebral circulation as quickly as possible after cardiac arrest is mandatory for a good outcome. In this report patients with a witnessed cardiac arrest receiving LUCAS-CPR within 15 min from the ambulance call had a 30-day survival of 25% in VF and 5% in asystole, but if the interval was more than 15 min, there were no 30-day survivors.

[Development of a mobile digital hydraulic extracorporeal heart compression machine]

This article introduces the working principle, the structural design of a mobile digital hydraulic extracorporeal heart compression machine and its trial result on the human model. The result shows that the machine which has the advantages of easy operation, fast effectiveness, safety, line display and agile adjustment, is an ideal medical device for patients with cardiac arrest and is of great social benefit and great market expectations.

Increased cortical cerebral blood flow with LUCAS; a new device for mechanical chest compressions compared to standard external compressions during experimental cardiopulmonary resuscitation

OBJECTIVE

LUCAS is a new device for mechanical compression and decompression of the chest during cardiopulmonary resuscitation (CPR). The aim of this study was to compare the efficacy of this new device with standard manual external chest compressions using cerebral cortical blood flow, cerebral oxygen extraction, and end-tidal CO2 for indirect measurement of cardiac output. Drug therapy, with adrenaline (epinephrine) was eliminated in order to evaluate the effects of chest compressions alone.

METHODS

Ventricular fibrillation (VF) was induced in 14 anaesthetized pigs. After 8 min non-intervention interval, the animals were randomized into two groups. One group received external chest compressions using a new mechanical device, LUCAS. The other group received standard manual external chest compressions. The compression rate was 100 min(-1) and mechanical ventilation was resumed with 100% oxygen during CPR in both groups. No adrenaline was given. After 15 min of CPR, external defibrillatory shocks were applied to achieve restoration of spontaneous circulation (ROSC). Cortical cerebral blood flow was measured continuously using Laser-Doppler flowmetry. End-tidal CO2 was measured using mainstream capnography.

RESULTS

During CPR, the cortical cerebral blood flow was significantly higher in the group treated with LUCAS (p = 0.041). There was no difference in oxygen extraction between the groups. End-tidal CO2, an indirect measurement of the achieved cardiac output during CPR, was significantly higher in the group treated with the LUCAS device (p = 0.009). Restoration of spontaneous circulation was achieved in two animals, one from each group.

CONCLUSIONS

Chest compressions with the LUCAS device during experimental cardiopulmonary resuscitation resulted in higher cerebral blood flow and cardiac output than standard manual external chest compressions. These results strongly support prospective randomised studies in patients to evaluate this new device.

Improved hemodynamic performance with a novel chest compression device during treatment of in-hospital cardiac arrest

INTRODUCTION

The purpose of this pilot clinical study was to determine if a novel chest compression device would improve hemodynamics when compared to manual chest compression during cardiopulmonary resuscitation (CPR) in humans. The device is an automated self-adjusting electromechanical chest compressor based on AutoPulse technology (Revivant Corporation) that uses a load distributing compression band (A-CPR) to compress the anterior chest.

METHODS

A total of 31 sequential subjects with in-hospital sudden cardiac arrest were screened with institutional review board approval. All subjects had received prior treatment for cardiac disease and most had co-morbidities. Subjects were included following 10 min of failed standard advanced life support (ALS) protocol. Fluid-filled catheters were advanced into the thoracic aorta and the right atrium and placement was confirmed by pressure waveforms and chest radiograph. The coronary perfusion pressure (CPP) was measured as the difference between the aortic and right atrial pressure during the chest compression's decompressed state. Following 10 min of failed ALS and catheter placement, subjects received alternating manual and A-CPR chest compressions for 90 s each. Chest compressions were administered without ventilation pauses at 100 compressions/min for manual CPR and 60 compressions/min for A-CPR. All subjects were intubated and ventilated by bag-valve at 12 breaths/min between compressions. Epinephrine (adrenaline) (1mg i.v. bolus) was given at the request of the attending physician at 3-5 min intervals. Usable pressure signals were present in 16 patients (68 +/- 6 years, 5 female), and data are reported from those patients only. A-CPR chest compressions increased peak aortic pressure when compared to manual chest compression (153 +/- 28 mmHg versus 115 +/- 42 mmHg, P < 0.0001, mean +/- S.D.). Similarly, A-CPR increased peak right atrial pressure when compared to manual chest compression (129 +/- 32 mmHg versus 83 +/- 40 mmHg, P < 0.0001). Furthermore, A-CPR increased CPP over manual chest compression (20 +/- 12 mmHg versus 15 +/- 11 mmHg, P < 0.015). Manual chest compressions were of consistent high quality (51 +/- 20 kg) and in all cases met or exceeded American Heart Association guidelines for depth of compression.

CONCLUSION

Previous research has shown that increased CPP is correlated to increased coronary blood flow and increased rates of restored native circulation from sudden cardiac arrest. The A-CPR system using AutoPulse technology demonstrated increased coronary perfusion pressure over manual chest compression during CPR in this terminally ill patient population.

[A portable sternal compressor for cardiac massage on a patient carried by a litter--Part 3: Applicability of the device tested by a recording manikin]

Effects of a portable sternal compressor developed by us was examined by 43 medical students (28 males and 15 females) and 9 anesthesia residents using a recording manikin. Compression over a depth of 3.5 to 5.0 cm was classified as adequate. First, the examinee held the device affixed in front of the chest with a belt hanged over the shoulder and pulled the other handle back and forth at a rate of 100 per minute. The male students could perform adequate compression in 92% of the total number of compression in the first one minute, while female students could in 65%. Though the anesthesia residents accomplished 99% of success rate in the first one minute, the rate fell to nearly 80% in the next minute and about 50% thereafter due to fatigue. When one handle was sustained on the floor with its fold-in stand and held between the knees of the examinee sitting on a chair, adequate compression was performed with the success rate of over 80% for 5 minutes. We conclude this device will be useful for cardiac massage on a patient either transported on a litter or lying on a soft bed.

Improvement in timing and effectiveness of external cardiac compressions with a new non-invasive device: the CPR-Ezy

Prompt and effective cardiopulmonary resuscitation (CPR) is the first link in the chain of survival following cardiac arrest. We assessed a new device, the CPR-Ezy (Medteq Innovations Pty Ltd., Brisbane, Australia), to aid timing and effectiveness of external cardiac compressions (ECC), by 32 subjects who had prior community-based training in CPR. ECC was performed on a manikin for 4 min by all subjects without and with the device. There was a statistically significant improvement in timing of ECC. Effectiveness of compressions was also improved over the whole time period, especially so in the last minute. We conclude that the CPR-Ezy can improve timing and effectiveness of ECC, and reduce the effects of resuscitator fatigue, in community-trained subjects.

Alternative cardiopulmonary resuscitation devices

Cardiac arrest survival rates remain low despite increased access to advanced cardiac life support. Survival from cardiac arrest is, at least in part, related to the perfusion pressures and blood flow achieved during cardiopulmonary resuscitation (CPR). A number of alternative CPR devices have been developed that aim to improve the perfusion pressures and/or blood flow achieved during CPR. Active compression-decompression CPR devices are by far the most studied alternative CPR devices, but the results have been inconsistent and conflicting. A number of other devices, including the inspiratory impedance threshold valve, minimally invasive direct cardiac massage, phased chest and abdominal compression-decompression CPR, and vest CPR, are all capable of improving perfusion pressures and/or blood flow compared with standard external chest compressions. However, no convincing human outcome data has been produced yet for any of these devices. Although an interesting area of research, none of the alternative CPR devices convincingly improve long-term patient outcomes.

Insertion of the minimally invasive direct cardiac massage device (MIDCM): training on human cadavers

OBJECTIVE

Recently, a new device for minimally invasive direct cardiac massage (MIDCM) has been developed. In animal models of cardiopulmonary resuscitation MIDCM has been shown to provide better organ perfusion than external chest compressions (ECC) massage. Since this device has been developed to improve cardiopulmonary resuscitation in humans, its use must be simple. Thus, we measured the time required for the insertion of the MIDCM device on human cadavers.

DESIGN

After a 1 h theoretical course, physicians and surgeons were asked to use the MIDCM device on human cadavers. We measured the time from the cutaneous incision to the first direct cardiac compression.

MAIN RESULTS

The mean time required for the insertion of the MIDCM device was 16+/-11 s (range 8-58 s). The insertion time required for each group of physicians were as follows, 15+/-8 s for anaesthesiologists (range 8-28 s), 11+/-2 s for cardiac surgeons (range 9-15 s), 42+/-14 s for cardiologists (range 27-58 s), and 12+/-4 s for intensive care physicians (range 8-18). All participants compared the insertion of the MIDCM device favorably with the insertion of a chest drain.

CONCLUSION

The MIDCM device can be placed in a few seconds in human cadavers by physicians familiar with chest drain insertion. Theoretical course and training with the device may be useful especially for those who are not familiar with chest drain insertion.

Prehospital use of minimally invasive direct cardiac massage (MID-CM): a pilot study

BACKGROUND

Internal cardiac compressions are more efficient than closed chest compressions (CCC) in cardiac arrest (CA).

AIM OF THE STUDY

To evaluate the prehospital feasibility of performing a new method of minimally invasive direct cardiac massage (MID-CM TheraCardia Inc.).

METHODS

Prospective non-randomized open study, after ethical committee approval. Inclusion of 18-85 years old patients in witnessed CA if BLS>5 min and unsuccessful ACLS>20 min after CA. The MID-CM is an atraumatic manual cardiac pumping system deployed in the thoracic cavity through a small incision. Evaluation of: ease of insertion and performing MID-CM, complications, end-tidal CO(2) (PETCO(2)), non invasive arterial blood pressure (NIBP) and return of spontaneous circulation (ROSC). Values are mean+/-SD (min-max).

RESULTS

Twenty-five patients included. Mean age 59+/-16 years (26-85); BLS started at 8+/-5 min (0-20), compressions started at 47+/-10 min (29-74) after CA. Dissection and insertion was fast and easy (<1 min). Deployment of the MID-CM was difficult in two patients because of pericardium adhesions and cardiomegaly. In six patients compressions were more difficult because of a 'stone heart' phenomenon. Compressions were possible during ambulance transport of four patients. There was a good palpable carotid pulse in all patients receiving internal compressions. There was a trend in increase of PETCO(2) compared to CCC. NIBP could be measured during MID-CM compressions in 9 patients (systolic>85 mmHg), never during CCC. Seven patients had a ROSC, but only four patients were admitted alive. There was no long term survival. One patient had a serious complication (heart rupture).

DISCUSSION

Prehospital use of MID-CM is possible, but it is not comparable to any other resuscitation technique. Training of medical teams is mandatory to obtain good skills and to avoid complications. Further studies are necessary to evaluate efficiency and survival compared to closed chest compressions.