ABSTRACT
Objective To study the changes in and correlations between the partial pressure of end-tidal carbon dioxide (PETCO2) and the coronary perfusion pressure during cardio-pulmonary resuscitation (CPR) based on the cardiac arrest dog models of ventricular fibrillation by electric shock. Methods 36 healthy dogs were evenly randomized into 3 groups including 4 minutes close-chest CPR(CCCPR) group, 4 minutes open-chest CPR(OCCPR) group, and 8 minutes OCCPR group. There were 12 dogs in each group, half male and half female. In the process of CPR, all parameters about PETCO2 and CPP were recorded. Results In the 4 minutes CCCPR group, the correlation coefficient between the CPP and the PETCO2 was 0.992 (P<0.05), which was in positive linear correlation. In the 4 minutes OCCPR group, the correlation coefficient between the CPP and the PETCO2 was 0.937 (P < 0.05), which also showed positive linear correlation. In the 8 minutes OCCPR group, the correlation coefficient between the CPP and the PETCO2 was 0.952 (P<0.05), and was also in positive linear correlation. The percentage of ROSC was 66.7(8/12) in the 4 minutes CCOPR group, 100%(12/12) in the 4 minutes OCCPR group and 58.3%(7/12) in the 8 minutes OCCPR group. There were statistical differences in CPP, PETCO2 between models with ROSC and without ROSC at 1, 2, 5, 10, 15 and 20 mins of CPR (all P<0.05). Conclusions This research shows that there is a close positive linear relationship between the coronary perfusion pressure and the PETCO2, and PETCO2 could be used to evaluate the prognosis of the CPR.