Is the inter-nipple line the correct hand position for effective chest compression in adult cardiopulmonary resuscitation?
BACKGROUND
Despite the new release of CPR guidelines, there was insufficient evidence for or against a specific hand position for manual chest compression in adults. Computed tomography (CT) images of the chest can demonstrate objectively the spatial relationship between the surface landmarks on the chest and the inner viscera underneath them. This study is designed to examine the spatial relationship between the inter-nipple line (INL) and the heart in order to determine the proper hand position for more effective CPR.


METHODS
We enrolled 189 adult patients who underwent low dose chest CT from 16 October to 10 November 2006. Patients' demographic data were collected. The sternal length, the distance from the xiphoid to the INL, and the distance from the xiphoid to the maximal heart diameter were measured by using 3D reconstructed CT images.


RESULTS
In about 80% of the 189 patients' CT images, the intrathoracic structure just underneath the INL was the ascending aorta (18.0%), the root of aorta (48.7%), or the left ventricular outflow tract (12.7%), rather than the left ventricle itself (20.6%). The INL was 6.2+/-1.8cm and 5.6+/-1.9cm cephalad to the xiphoid for the male and the female, respectively. The coronal CT image plane of the maximal heart diameter was 2.8+/-1.6cm and 2.3+/-1.6cm cephalad to the xiphoid for the male and the female, respectively.


CONCLUSIONS
For more efficient and effective chest compression during CPR, compressing the sternum more caudally than the INL could be considered if it is not associated with the risk of increasing internal visceral injuries.
Shin
Jungho
J
Department of Emergency Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
Rhee
Joong Eui
JE
Kim
Kyuseok
K
D016887:Cardiopulmonary Resuscitation / Q000379:methods* / Q000592:standards; D005260:Female; D006225:Hand; D006323:Heart Arrest / Q000628:therapy*; D006336:Heart Massage / Q000379:methods* / Q000592:standards; D006801:Humans; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D012189:Retrospective Studies; D035441:Thoracic Wall / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome