Evolution and new perspective of chest compression mechanical devices

Manual and Mechanical Induced Peri-Resuscitation Injuries-Post-Mortem and Clinical Findings

(1) Background: Injuries related to resuscitation are not usually systematically recorded and documented. By evaluating this data, conclusions could be drawn about the quality of the resuscitation, with the aim of improving patient care and safety. (2) Methods: We are planning to conduct a multicentric, retrospective 3-phased study consisting of (1) a worldwide literature review (scoping review), (2) an analysis of anatomical pathological findings from local institutions in North Rhine-Westphalia, Germany to assess the transferability of the review data to the German healthcare system, and (3) depending on the results, possibly establishing potential prospective indicators for resuscitation-related injuries as part of quality assurance measures. (3) Conclusions: From the comparison of literature and local data, the picture of resuscitation-related injuries will be focused on and quality indicators will be derived.

Safety of mechanical and manual chest compressions in cardiac arrest patients: A systematic review and meta-analysis

AIM

Summarise the evidence regarding the safety of mechanical and manual chest compressions for cardiac arrest patients.

METHODS

Two investigators separately screened the articles of EMBASE, PubMed, and Cochrane Central databases. Cohort studies and randomized clinical trials (RCTs) that evaluated the safety of mechanical (LUCAS or AutoPulse) and manual chest compressions in cardiac arrest patients were included. A meta-analysis was performed using a random effects model to calculate the pooled odds ratios (ORs) and their 95% confidence intervals (CIs). The primary outcome was the rate of overall compression-induced injuries. The secondary outcomes included the incidence of life-threatening injuries, skeletal fractures, visceral injuries, and other soft tissue injuries.

RESULTS

The meta-analysis included 11 trials involving 2,818 patients. A significantly higher rate of overall compression-induced injuries was found for mechanical compressions than manual compressions (OR, 1.29; 95% CI, 1.19-1.41), while there was no significant difference between the two groups in respect of the rate of life-threatening injuries. Furthermore, both modalities shared similar incidences of sternal fractures, vertebral fractures, lung, spleen, and kidney injuries. However, compared to mechanical compressions, manual compressions were shown to present a reduced risk of posterior rib fractures, and heart and liver lesions.

CONCLUSIONS

The findings suggested that manual compressions could decrease the risk of compression-induced injuries compared to mechanical compressions in cardiac arrest patients. Interestingly, mechanical compressions have not increased the risk of life-threatening injuries, whereas additional high-quality RCTs are needed to further verify the safety of mechanical chest devices.

TRIAL REGISTRY

INPLASY; Registration number: INPLASY2020110111; URL: https://inplasy.com/.

Blood flow maintenance by cardiac massage during cardiopulmonary resuscitation: Classical theories, newer hypotheses, and clinical utility of mechanical devices

The mechanisms by which closed chest cardiac massage produces and maintains blood flow during cardiopulmonary resuscitation are still debated. To date, two main theories exist: the "cardiac pump", which assumes that blood flow is driven by direct cardiac compression and the "chest pump", which hypothesizes that blood flow is caused by changes in intrathoracic pressure. Newer hypotheses including the "atrial pump", the "lung pump", and the "respiratory pump" were also proposed. We reviewed studies supporting these different theories as well as the clinical evidences on the utility of mechanical devices proposed to optimize cardiopulmonary resuscitation, in view of their pathophysiological assumptions with regard to the underlying theory. On the basis of current evidence, a single theory is probably not sufficient to explain how cardiac massage produces blood flow. This suggests that different simultaneous mechanism might be involved. The relative importance of these mechanisms depends on several factors, including delay from collapse to starting of resuscitation, compression force and rate, body habitus, airway pressure, and presenting electrocardiogram. The complexity of the physiologic events occurring during cardiopulmonary resuscitation, together with the need of adequate training for a correct and prompt utilization of mechanical devices, might also partially explain the disappointing results of these devices in most clinical studies.

Traumatic injuries after mechanical cardiopulmonary resuscitation (LUCAS2): a forensic autopsy study

AIM

The aim of our study was to compare traumatic injuries observed after cardiopulmonary resuscitation (CPR) by means of standard (manual) or assisted (mechanical) chest compression by Lund University Cardiopulmonary Assist System, 2nd generation (LUCAS2) device.

METHODS

A retrospective study was conducted including cases from 2011 to 2013, analysing consecutive autopsy reports in two groups of patients who underwent medicolegal autopsy after unsuccessful CPR. We focused on traumatic injuries from dermal to internal trauma, collecting data according to a standardised protocol.

RESULTS

The study group was comprised of 26 cases, while 32 cases were included in the control group. Cardiopulmonary resuscitation performed by LUCAS2 was longer than manual CPR performed in control cases (study group: mean duration 51.5 min; controls 29.4 min; p = 0.004). Anterior chest lesions (from bruises to abrasions) were described in 18/26 patients in the LUCAS2 group and in 6/32 of the control group. A mean of 6.6 rib fractures per case was observed in the LUCAS2 group, but this was only 3.1 in the control group (p = 0.007). Rib fractures were less frequently observed in younger patients. The frequency of sternal factures was similar in both groups. A few trauma injuries to internal organs (mainly cardiac, pulmonary and hepatic bruises), and some petechiae (study 46%; control 41 %; p = 0.79) were recorded in both groups.

CONCLUSION

LUCAS™2-CPR is associated with more rib fractures than standard CPR. Typical round concentric skin lesions were observed in cases of mechanical reanimation. No life-threatening injuries were reported. Petechiae were common findings.

Manual and automated cardiopulmonary resuscitation (CPR): a comparison of associated injury patterns

The purpose of this study was to identify and compare patterns of trauma associated with AutoPulse(®) CPR and manual CPR. Finalized autopsy records from 175 decedents brought to the Harris County Institute of Forensic Sciences were reviewed, 87 received manual-only CPR, and 88 received AutoPulse(®) CPR (in combination with manual CPR as per standard protocol). The characteristic pattern observed in manual-only CPR use included a high frequency of anterior rib fractures, sternal fractures, and midline chest abrasions along the sternum. The characteristic pattern observed in AutoPulse(®) CPR use included a high frequency of posterior rib fractures, skin abrasions located along the anterolateral chest and shoulder, vertebral fractures, and a few cases of visceral injuries including liver lacerations, splenic lacerations, and hemoperitoneum. Knowledge of the AutoPulse(®) CPR injury pattern can help forensic pathologists differentiate therapeutic from inflicted injuries and therefore avoid an erroneous assessment of cause and manner of death.

Single rescuer exertion using a mechanical resuscitation device: a randomized controlled simulation study

OBJECTIVES

The goal of this experimental study was to investigate rescuer exertion when using "Animax," a manually operated hand-powered mechanical resuscitation device (MRD) for cardiopulmonary resuscitation (CPR), compared to standard basic life support (BLS).

METHODS

This was a prospective, open, randomized, crossover simulation study. After being trained, 80 medical students with substantial knowledge in BLS performed one-rescuer CPR using either the MRD or the standard BLS for 12-minute intervals in random order. The main outcome parameter was the heart rate pressure product (RPP) as an index of cardiac work. Secondary outcome parameters were physical exhaustion quantified by the Borg scale (measurement of perceived exertion), Nine Hole Peg Test (NHPT; measurement of fine motor skills), and capillary lactate concentration during testing.

RESULTS

While no significant difference could be found for the RPP, a significantly increased mean heart rate during the final minute of standard BLS compared to the MRD was found (139 ± 22 beats/min vs. 135 ± 26 beats/min, p = 0.027). By contrast, subjective exertion using the MRD was rated significantly higher on the Borg scale (15.1 ± 2.4 vs. 14.6 ± 2.6, p = 0.027). Mean serum lactate concentration was significantly higher when the MRD was used compared to standard BLS (3.4 ± 1.5 mmol/L vs. 2.1 ± 1.3 mmol/L, p ≤ 0.001).

CONCLUSIONS

Use of the MRD leads to a RPP of the rescuers comparable to standard BLS. These findings suggest that there is no clinically relevant reduction of exertion if this MRD is used by a single rescuer. If this kind of MRD is used for CPR, frequent changeovers with a second rescuer should be considered as the guidelines suggest for standard CPR.