Comparison of Heart Proportions Compressed by Chest Compressions Between Geriatric and Nongeriatric Patients Using Mathematical Methods and Chest Computed Tomography: A Retrospective Study

Abstract

Background Current guidelines recommended that chest compression depths during car-diopulmonary resuscitation (CPR) should be at least one-fifth of the external chest ante-riorposterior (AP) diameter. The chest AP diameter increases because of dorsal kyphosis, senile emphysema, and poor lung compliance associated with aging. This study aimed to compare the proportion of the heart compressed by chest compression (based on the ejection fraction [EF]) in geriatric and nongeriatric patients. Methods We performed a retrospective analysis of the chest computed tomography findings obtained between January 2010 and August 2016 and measured the chest anatomical parameters such as the perpendicular external and internal chest AP diameters with the heart AP diameter. Based on values of these parameters, EFs with 50- and 60-mm depths were obtained. In addition, we investigated and compared the proportion of 50- and 60-mm depths and heart AP to external chest AP diameter between the 2 groups. Results We randomly selected and analyzed 100 of 1,921 geriatric and 100 of 22,090 nongeriatric populations from a database. The means±standard deviations of EFs with 50- and 60-mm depths for geriatric and nongeriatric people were 37.1%±12.1% vs. 43.2%±13.8% and 47.5%±12.8% vs. 54.6%±14.8%, respectively (all p<0.001). The proportion of 50- and 60-mm depths and heart AP to external chest AP diameter were significantly different between the 2 groups (all p<0.05). Conclusion Chest compression depths based on current guidelines are not sufficient for geriatric patients during CPR; hence, deeper chest compressions would be considered.

Using computed tomography to evaluate proper chest compression depth for cardiopulmonary resuscitation in Thai population: A retrospective cross-sectional study

“…Our results indicated that lower HCF was found among higher BMI groups which were consistent with the previous findings [15,19,21]. This might be explained by obese patients having a wider thoracic compartment and larger non-cardiac soft tissue, whereas CC depth was fixed at 50 mm to 60 mm.…”

“…Based on the cardiac pump model, direct CC mainly generated approximately 33% of the ejection fraction in normal adults, i.e., EF of 67% in 70 kilograms of healthy people [6,7]. The results of mean HCF from 38.3% to 50% were estimated by 50 mm and 60 mm CC depth and were consistent with other findings in Asia, which ranged from 37.1% to 54.6% [15,19,21]. Therefore, 50 mm to 60 mm CC depths might generate sufficient cardiac output during CPR.…”

“…The characteristics of our subjects were elderly and normal to overweight BMI groups, which were not different from the subjects reported in the previous studies in Asia [15,19,21]. Although 47.4% of our subjects had lung diseases, which were not reported in the earlier studies, external and internal chest, as well as heart diameter, was not clinically different (216.2 mm VS 220 mm and 105.2 mm VS 107.9 mm) [14].…”

“…Moreover, higher BMI patients significantly presented higher chest compartment diameters despite their lower HCF [15,19,20]. In addition, some evidence suggested that 50 mm to 60 mm chest compression depth generated inadequate HCF among geriatric patients [21]. In contrast, previous research recommended performing deeper CC in special populations, which consequently reported complications such as sternal/rib fractures, flail chest, pneumohemothorax, and liver laceration [22][23][24][25][26].…”

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

“…The use of computed tomography (CT) to calculate the heart compression fraction (HCF), which represents the blood flow generated during CPR, has been suggested for comparison of the appropriate CC depth 7 , 8 , 9 . Previous recommendations of a 50- and 60-mm CC depth were generalized and not categorized by factors such as sex, BMI, or specific diseases of the thoracic cage.…”