Validation Of BNP And APACHE â…¡ Score In Prognosis Assessment Of Critically-ill Patients

Objective:All ICU Admissions were tested on plasma BNP(B-Type Natriureic Peptide) level and evaluated by APACHEⅡ(Acute Physiology and Chronic Health EvaluationⅡ) scoring system in order to investigate the validity of both BNP and APACHEⅡin prognosis assessment of critically-ill patients.Method:Data were collected prospectively on 62 ICU admissions from March 2008 to July 2008.The APACHEⅡscore was calculated and plasma BNP level was measured within the first 24 hours after admission.Validity of both BNP and APACHEⅡscore was evaluated by analyzing the correlation among a few prognosis prediction parameters,i.e.the survival time,length of hospitalization,no.of cases which require mechanical ventilation,and the percentage of ventilation duration over the whole period of hospitalization.Result:There were 62 admissions with APACHEⅡscored 13-39(Mean 24.35±7.26) and mean plasma BNP level of 11.65.15±1120.76 pg/ml.44 survivals had the APACHEⅡscored 22.30±6.80 and plasma BNP level of 861.57±1006.77 pg/ml.18 deaths had the APACHEⅡscored 29.39±5.84 and plasma BNP level of 1907.23±1059.15 pg/ml.Mean APACHEⅡscore and plasma BNP level of the survival group are higher than those of the non-survival group showing statistic significance(P＜0.01). 62 patients were divided into three groups according to their APACHEⅡscores (GroupⅠ:≤15;GroupⅡ:16-30;GroupⅢ:≥30).Q tests were performed withα=0.05. Differences of plasma BNP level among the three groups are of statistic significance (P＜0.05),indicating that the plasma BNP level would increase with the increased APACHEⅡscore.By Chi-square test,use of mechanical ventilation among the three groups increased with the increased APACHEⅡscore,rates of application are 14.3%, 57.5%and 93.3%respectively.Rates of application of mechanical ventilation among the three groups are different showing statistic significance(α2=13.253,P=0.001). Total rates of mechanical ventilation application are 61.3%.Mortality rates among the three groups are of statistic differences,which are 0%,15.0%and 66.7%respectively, and these increased with increased APACHEⅡscore(α2=14.759,P=0.001).Total mortality rates are 23.8%.62 patients were divided into four groups according to their plasma BNP level(GroupⅠ:≤95;GroupⅡ:95-459;GroupⅢ:459-1006;GroupⅣ:≥1006).Q tests were performed withα=0.05.Differences of APACHEⅡscores among the four groups are of statistic significance(P＜0.05),indicating that the APACHE score would increase with the increased plasma BNP level.By Chi-square test,use of mechanical ventilation among the four groups increased with the increased plasma BNP level,rates of application are 12.5%,50.0%,63.2%and 81.0% respectively.Rates of application of mechanical ventilation among the four groups are different showing statistic significance(α2=11.990,P=0.007).Total rates of mechanical ventilation application are 59.7%.Mortality rates among the four groups are of statistic differences,which are 0%,15.0%and 66.7%respectively,and these increased with increased plasma BNP level(α2=13.392,P=0.004).Total mortality rates are 29.0%.44 survivals were divided into four groups according to their plasma BNP level(GroupⅠ:≤95;GroupⅡ:95-459;GroupⅢ:459-1006;GroupⅣ:≥1006). Q tests were performed withα=0.05.Duration of mechanical ventilation and length of hospitalization among the four groups are of statistically significant differences (P=0.047),indicating that both the duration of mechanical ventilation and length of hospitalization increased with increased plasma BNP level.Conclusion:Plasma level of BNP and APACHEⅡscoring system are of high validity in prognosis assessment of critically ill patients,including survival rates,rates of mechanical ventilation application,duration of ventilation and length of hospitalization.