充血性心力衰竭与重症肺炎患儿血清脑钠素浓度变化的研究

Levels of serum brain natriuretic peptide in children with congestive heart failure or with severe pneumonia

目的B型利钠肽即脑钠素（B—type or brain natriuretic peptide，BNP）在成人充血性心力衰竭（congestive heart failure，CHF）时血浆浓度显著升高，对成人CHF有重要诊断价值，对成人急性呼吸困难有重要的鉴别诊断价值。在小儿有关BNP的研究不多，该实验旨在研究小儿CHF及肺炎时血清BNP浓度变化，探讨BNP对小儿急性呼吸困难的鉴别诊断价值；进一步探讨小儿重症肺炎是否会合并心衰，为肺炎合并心衰的诊断寻找客观指标。方法将65例有呼吸困难症状的患儿分为3组：CHF组（即心源性呼吸困难组）24例；肺炎组（即肺源性呼吸困难组）23例；临床诊断肺炎心衰组18例。对10例肺炎合并心衰患儿在病情平稳2—3d后再次收集血清。正常对照组15例。用ELISA法测血清BNP浓度。结果CHF组血清BNP浓度显著高于临床诊断肺炎心衰组、肺炎组及正常组（P〈0．01）；临床诊断肺炎心衰组显著高于肺炎组（P〈0．01）及正常组（P〈0．01），肺炎组与正常组比较差异无显著性。BNP对心源性呼吸困难鉴别诊断的受试者作业特征曲线（receive operator characteristic，ROC curve）下面积是0．978（P〈0．01）；BNP以49pg／mL为诊断界值，对呼吸困难由CHF引起的诊断敏感度是87．5％，特异度是95．8％；临床诊断肺炎心衰的18例患儿中，BNP浓度〉49pg／mL的11例，其BNP浓度为172．08±56．47pg／mL，显著高于肺炎组（P〈0．01），与CHF组相比无差异；这11例中有10例治疗后复查血清BNP，其浓度为26．12±15．71pg／mL，低于治疗前（P〈0．01）。另7例血清BNP浓度为20．46±11．78pg／mL，与肺炎组及正常组相比差异无显著性（均P〉0．05）。结论BNP浓度检测对小儿呼吸困难是否由CHF引起有鉴别诊断价值；小儿重症肺炎时可以合并心力衰竭；BNP检测可鉴小儿重症肺炎是否合并心力衰竭。

Objective Some research has shown that B-type brain natriuretic peptide （BNF） is helpful in differentiating cardiac from pulmonary etiologies of dyspnea in adults. This study was designed to investigate whether BNP concentration could be similarly applied in children presenting with dyspnea. Methods Blood samples were collected from 65 children presenting with dyspnea, due to congestive heart failure （ CHF, n = 24）, pneumonia （ n = 23 ） or pneumonia together with CHF （n = 18）. The samples from 15 healthy children were used as the controls. There were no significant differences in age among the four groups. Serum BNP levels were measured using ELISA. Results Serum BNP levels in the CHF group （ 141.55 ± 75. 99 pg/mL） were significantly higher than those in the Pneumonia group （26. 00 ± 14.57 pg/mL; P 〈0.01 ）, and the Pneumonia together with CHF group （ 113.73 ±87.05 pg/mL; P 〈0.05）, as well as the Control group （19.31 ± 10.30 pg/mL; P 〈0. 01 ）. The patients with pneumonia together with CHF had significantly higher serum BNP levels than those of the Pneumonia and the Control groups （ P 〈 0. 01 ）. There were no significant differences in BNP levels between the Pneumonia and the Control groups. The area under the receive operator characteristic （ROC） curve, which demonstrated the diagnostic utility of BNP in differentiating CHF from pneumonia, was 0. 978 （ P 〈0. 01）. At a cut-off of 49 pg/mL, BNP had a sensitivity of 87.5% and a specificity of 95.8% for differentiating CHF from pneumonia. In the 18 patients who were diagnosed with pneumonia together with CHF, 11 had BNP levels above 49 pg/mL. The mean levels of BNP of the 11 patients were significantly higher than those of the patients with pneumonia （ 172.08 ± 56.47 pg/mL vs 25.00 ± 14.57 pg/mL ; P 〈 0.01 ） but were significantly decreased after treatment （ 26.12 ± 15.71 pg/mL; P〈0.01）. Conclusions BNP level is of value in differentiating cardiac from pulmonary causes of dyspnea in children. BNP level is also helpful in assessing whether or not severe pneumonia couples with heart failure in children.