Abstract 199: Relationship Between the Blood Hemoglobin Concentration and the Initial Rhythm in Out-of-Hospital Cardiac Arrest (Interim Analysis From SOS-KANTO 2012)
BACKGROUND: Tissue metabolism that is reflected by oxygen consumption is regulated by the blood hemoglobin concentration (Hb) and cardiac output. Cardiac output during cardiac arrest has been suggested to be related to the quality of CPR. Although Hb might theoretically play a crucial role in maintaining tissue metabolism during cardiac arrest, this has not yet been well studied. If myocyte metabolism during cardiac arrest were affected by Hb, the sustainability of myocytes’ electrical activities may be correlated with the Hb.
HYPOTHESIS: The probability of asystole being observed as the initial rhythm by emergency personnel at the scene of a cardiac arrest (CA) is higher in cardiac arrest patients with lower Hb than in those with higher Hb.
METHODS: In an interim analysis of the data in the SOS-KANTO 2012 Study, a multicenter prospective observational study, there were 6,019 CA registrations in the KANTO area, Japan. Of these, Hb was checked in 4,611 cases. Of the 4611 cases, there were 705 subjects 15 years old or over of out-of-hospital CA with a presumed cardiac etiology, in whom the CA was confirmed by emergency personnel at the scene and who were identified as having no disabilities of daily living. Of the 705, 130 males who received bystander chest compressions in whom Hb ranged between 5.0 and 20 g/dl (median 13 g/dl) were included in this study.
Results: Of the 130 cases, asystole and VE/VT were confirmed as the initial rhythm at the scene by emergency personnel in 39 (30%) and 61 (47%) cases, respectively. Hb was lower in the asystole group than that in the non-asystole group (12.3+/-2.7 g/dl vs. 13.3+/-2.6 g/dl, P=0.04). A multivariate logistic regression analysis showed that Hb and later arrival of emergency personnel at the scene of emergency collapse were independent predictors of identification of asystole as the initial rhythm at the site of CA (odds ratio [95%CI]: 0.82 [0.75-0.90], P<0.01, 1.18 [1.06-1.30], P<0.01, respectively).
CONCLUSIONS: Lower Hb in the blood was associated with a higher likelihood of asystole at the scene of CA. Our findings suggested that VF/VT and/or PEA easily disappear and change to asystole in victims with lower Hb, although further study is needed.
- © 2013 by American Heart Association, Inc.