Abstract P175: Impact of Serum Hemoglobin Level for Successful Cardiac Resuscitation
Aim: It has been recently recognized that anemia is one of risk factors for major adverse cardiac events among the patients with cardiac diseases. However, it is unknown whether serum hemoglobin level could affect the outcome of cardiac resuscitation. We hypothesize that cardiac resuscitation in patients with anemia is less successful than in those without anemia.
Methods: This retrospective observation study was conducted in an academic emergency department (ED) in Tokyo. During the period of 30 months since January 2002, 164 patients with out-of-hospital cardiac arrest were brought to the ED by ambulance. Of those, 139 cardiac arrests were caused by acute illness. Excluding 51 arrests without witness, the remaining 88 patients (67±16 y/o, 66 male) with cardiac arrest including 66 presumed by cardiac etiology were entered into this study. Ventricular fibrillation was observed in 24 patients and asystole was observed in 20 patients as an initial rhythm. Bystander chest compressions were performed in 39 patients, whereas bystander rescue breathes were done in 33 patients. Serum hemoglobin level at the ED arrival was obtained and compared in patients between dead or restored spontaneous circulation followed by admitting to the ward as the outcomes at the ED.
Results: Of the 88 patients, 22 patients were restored and kept their spontaneous circulation and admitted to the wards, whereas the remaining 66 patients died at the ED. Serum hemoglobin level was higher in the died group than in the admitted group (12.4±2.5 mg/dl, 11.5±3.3 mg/dl, respectively, P=0.25). A logistic regression analysis with backward elimination method revealed that asystole as an initial rhythm (Odds ratio=4.05, 95% confidence interval: 1.07 to 15.33), presumed cardiac cause (3.16, 1.02 to 9.76), serum hemoglobin level (1.23, 1.01 to 1.52), and bystander chest compression (0.28, 0.09 to 0.87) were the independent predictors for the death at the ED.
Conclusion: Multivariate model showed that higher serum hemoglobin level was related to worse outcome at the ED. This result suggests that hemodilution is advantageous for cardiac resuscitation. Further studies are clearly needed to elucidate its underlying mechanisms and its effects on long term survival with/without neurological deficit.