Appropriateness of recommended chest compression depths for cardiopulmonary resuscitation based on chest computed tomography parameters among Thai population: A multicenter retrospective study

Aim : We evaluated the appropriateness of various chest compression (CC) depths among Thai population by comparing the calculated heart compression fraction (HCF) using mathematical methods based on chest computed tomography (CT) measurements. Methods : This multicenter retrospective cross-sectional study was conducted from September 2014 to December 2020. Chest parameters included external anteroposterior diameter (EAPD), internal anteroposterior diameter (IAPD), heart anteroposterior diameter (HAPD), and non -cardiac soft tissue measured at the level of maximum left ventricular diameter (LVmax). We compared the HCFs as calculated from CT parameters using different CC depths at 5 cm, 6 cm, 1/4 of EAPD, and 1/3 of EAPD, with further subgroup analysis stratified by sex and BMI. Results : A total of 2927 eligible adult patients with contrast -enhanced chest CT were included. The study group had mean age of 60.1 +/- 14.7 years, mean BMI of 22 +/- 4.4 kg/m 2 , and were 57% males. The mean HCFs were 41.5%, 53.5%, 42.4%, and 62.6%, for CC depths of 50 mm, 60 mm, 1/4 of EAPD, and 1/3 of EAPD respectively. HCF was significantly lower in male patients for all CC depths. Advanced age and higher BMI showed significant correlation with lower HCF for CC depths of 50 mm and 60 mm. Conclusion : The CC depth measure of 50-60 mm demonstrated efficacy in maintaining HCF and coronary perfusion in the general population except for geriatric and obese individuals. Adjusting CC depth to 1/4-1/3 of the EAPD yielded better outcomes. Future research should prioritize determining individualized CC depths based on EAPD proportion.