title: The uniform chest compression depth of 50 mm or greater recommended by current guidelines is not appropriate for all adults.
abstract: OBJECTIVE
  This study was conducted to evaluate the appropriateness of the chest compression (CC) depth recommended in the current guidelines and simulated external CCs, and to characterize the optimal CC depth for an adult by body mass index (BMI).
  
  
  METHODS
  Adult patients who underwent chest computed tomography as a screening test for latent pulmonary diseases in the health care center were enrolled in this study. We calculated the internal anteroposterior (AP) diameter (IAPD) and external AP diameter (EAPD) of the chest across BMIs (<18.50, 18.50-24.99, 25.00-29.99, and ≥30.00 kg/m(2)) for simulated CC depth. We also calculated the residual chest depths less than 20 mm for simulated CC depth.
  
  
  RESULTS
  There was a statistically significant difference in the chest EAPD and IAPD measured at the lower half of the sternum for each BMI groups (EAPD: R(2) = 0.638, P < .001; IAPD: R(2) = 0.297, P < .001). For one-half external AP CC, 100% of the patients, regardless of BMI, had a calculated residual internal chest depth less than 20 mm. For one-fourth external AP CC, no patients had a calculated residual internal chest depth less than 20 mm. For one-third external AP CC, only 6.48% of the patients had a calculated residual internal chest depth less than 20 mm.
  
  
  CONCLUSIONS
  It is not appropriate that the current CC depth (≥50 mm), expressed only as absolute measurement without a fraction of the depth of the chest, is applied uniformly in all adults. In addition, in terms of safety and efficacy, simulated CC targeting approximately between one-third and one-fourth EAPD CC depth might be appropriate.
authors.affiliation: Department of Emergency Medicine, Gyeongsang National University Hospital, Jinju, Gyeongsangnam-Do, Republic of Korea. Electronic address: ssoon0702@naver.com.
authors.forename: Soo Hoon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Emergency Medicine, Gyeongsang National University Hospital, Jinju, Gyeongsangnam-Do, Republic of Korea.
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Emergency Medicine, Gyeongsang National University Hospital, Jinju, Gyeongsangnam-Do, Republic of Korea.
authors.forename: Tae-Sin
authors.initials: TS
authors.lastname: Kang
authors.affiliation: Department of Emergency Medicine, Gyeongsang National University Hospital, Jinju, Gyeongsangnam-Do, Republic of Korea.
authors.forename: Changwoo
authors.initials: C
authors.lastname: Kang
authors.affiliation: Department of Emergency Medicine, Gyeongsang National University Hospital, Jinju, Gyeongsangnam-Do, Republic of Korea.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Jeong
authors.affiliation: Department of Emergency Medicine, Gyeongsang National University Hospital, Jinju, Gyeongsangnam-Do, Republic of Korea.
authors.forename: Seong Chun
authors.initials: SC
authors.lastname: Kim
authors.affiliation: Department of Emergency Medicine, Gyeongsang National University Hospital, Jinju, Gyeongsangnam-Do, Republic of Korea.
authors.forename: Dong Seob
authors.initials: DS
authors.lastname: Kim
mesh_terms: D000328:Adult; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D006336:Heart Massage / Q000592:standards*; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic / Q000592:standards*; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D013909:Thorax / Q000033:anatomy & histology*; D014057:Tomography, X-Ray Computed