Effect of a new mechanical chest compression device on cardiopulmonary resuscitation in pigs

Mao Yi; Mei Zhihan; Ma Haiying; Xu Shuai; Lu Yujie; Xu Jiefeng; Zhang Mao

doi:10.3969/j.issn.1002-1949.2025.07.002

Abstract：Objective To establish a pig model of cardiac arrest and to evaluate the the effect and safety of a new mechanical chest compression device MCC-E20 on cardiopulmonary resuscitation(CPR)in a pig model.Methods Twenty healthy male domestic pigs weighing 35-40 kg were randomly divided into sham group,old version compression device MCC-E group,and new version compression device MCC-E20 group.The sham group only underwent animal preparation without experiencing cardiac arrest and resuscitation.The MCC-E group and MCC-E20 group underwent cardiac arrest induced by delivering alternating current through right ventricular electrode for 6 minutes,followed by 8 minutes of CPR,to establish the porcine cardiac arrest and resuscitation model.During CPR,both groups followed international guidelines with compression parameters set at a rate of 100 compressions/min and a depth of 5 cm,while ventilation parameters were set to volume-controlled mode,tidal volume of 7 mL/kg,respiratory rate of 10 breaths/min,and oxygen concentration of 100％.Coronary perfusion pressure(CPP),end-tidal carbon dioxide(ETCO2)and carotid blood flow(CBF)were monitored in real-time during CPR.Arterial blood gases were measured at 1,4 and 7 min of CPR.Outcome indicators including successful rate of resuscitation,resuscitation time,defibrillation times,and reoccurrence of ventricular fibrillation were recorded.The stroke volume(SV)and global ejection fraction(GEF)were monitored by using pulse indicator continuous cardiac output(PiCCO)at 1,2 and 4 h post-resuscitation.Blood samples were collected via femoral vein at 1,2,4 and 24 h post-resuscitation for ELISA analysis of cardiac troponin I(cTnI),neuron-specific enolase(NSE),creatinine(Cr),and intestinal fatty acid binding protein(IFABP)levels.Neurological deficit score(NDS)was assessed at 24 h post-resuscitation followed by euthanasiarib,the rib fractures and bleeding from chest and abdominal organs were recorded.Results ①There were no significant differences in baseline body weight,HR,MAP,ETCO2,lactic acid and other physiological indicators among the groups(all P＞0.05).②During CPR,the indicators such as CPP,ETCO2 and CBF in the MCC-E20 group were higher than those in the MCC-E group,but the differences were not statistically significant(all P＞0.05).③During CPR,pH,PCO2,PaO2 and HCO3-values in the MCC-E20 group were higher than those in the MCC-E group,while lactate level was lower than that in the MCC-E group,but the differences between the groups were not statistically significant(all P＞0.05).④ There were 6 successful resuscitation and 1 failure in MCC-E20 group and MCC-E group.The successful rate of resuscitation,resuscitation time,defibrillation times and recurrent ventricular fibrillation times did not differ significantly between the MCC-E20 group and the MCC-E group(all P＞0.05).⑤ At 1,2,4 and 24 h after resuscitation,serum cTnI,NSE,IFABP and Cr levels in the MCC-E group and the MCC-E20 group were significantly higher than those in the Sham group.The values of cTnI,NSE,IFABP and Cr in the MCC-E20 group were lower than those in the MCC-E group,but the differences between the groups were not statistically significant(all P＞0.05).However,at 24 h after resuscitation,there was a significant difference in NDS scores between the two groups(P＜0.05).⑥Gross anatomy showed that the number of rib fractures in the MCC-E20 group was lower than that in the MCC-E group,and there was no thoracoabdominal organ bleeding in both groups,but the differences between the groups were not statistically significant(all P＞0.05).Conclusions This preliminary study suggests that the new MCC-E20 compression device is slightly better than the old version MCC-E device in terms of resuscitation efficacy,and they are comparable in terms of safety.It may be beneficial in reducing post-resuscitation organ damage and warrants further research.