无创性呼气末二氧化碳监测在急性哮喘儿童中的应用

Noninvasive end-tidal carbon dioxide measurements in children with acute asthma

目的 评价在急性哮喘患儿中监测呼气末二氧化碳分压（PetCO2）的临床意义,探讨PetCO2与动脉血二氧化碳分压（PaCO2）的相关性.方法 采用前瞻性、双盲的方法.我院儿科急诊收治的急性哮喘患儿65例,年龄5～14岁.在开始治疗前和每次喷雾治疗后（最多3次）由专职护士通过鼻套管接欧美达旁流式呼气末CO2监测仪无创性监测PetCO2,同时记录治疗前后的各项临床指标.治疗前抽动脉血检测PaCO2,抽血时间与第1次PetCO2测量时间相差不超过8 min.伴有心脏病、慢性肺病、组织灌注不良和代谢病的患儿被排除.结果 65例患儿治疗前、后PetCO2值分别是（34.8±8.6）mm Hg（1 mm Hg=0.133 kPa）（95%CI 34.0～36.1）和（33.2±8.2）mm Hg（95%CI32.5～34.4）,治疗后较治疗前明显下降,差异有非常显著性（P＜0.01）.但有8例患儿抽血时间与第1次PetCO2测量时间相差超过8 min,故予以排除.纳入研究的57例患儿,PaCO2值为（40.6±8.3）mm Hg,PetCO2为（34.8±7.6）mm Hg,两者高度相关（r=0.92,P＜0.000 1）.结论 在儿科急诊,对急性哮喘发作患儿行床边非侵入性监测PetCO2是可行的,PetCO2监测可反映急性哮喘患儿的通气功能状态,有助于判断PaCO2的变化,在儿童急性哮喘的管理中,可作为一个重要的辅助指标.

Objective To investigate the clinical significance of noninvasive detection of end-tidal carbon dioxide partial pressure （PetCO2） in the management of children with acute asthma, and to evaluate the association between PetCO2 and artery blood gas carbon dioxide partial pressure （ PaCO2 ）. Methods This was a prospective,double blinded study of children aged 5 ～ 14 years old treated for acute asthma in a pediatric emergency department. PetCO2 and PaCO2 measurements were taken before therapy and after each nebulization treatment （ maximum of three）. Various clinical parametesr were recorded. Patients with PaCO2 and PetCO2 measurements within 8 minutes of each other were eligible for inclusion. Patients with cardiac disease,chronic pulmonary disease, poor tissue perfusion, or metabolic abnormalities were excluded. Results Sixty five children were enrolled. The initial PetCO2 value was （34. 8 ±8. 6） mm Hg （95% confidence interval =34. 0 to 36. 1）. The PetCO2 value of post-treatment was （33.2 ±8.2） mm Hg （95% confidence interval =32. 5 to 34. 4） ,which was decreased significantly than that before treatment（P 〈 0. 01 ）. Fifty seven PetCO2-PaCO2 paired values were available from 57 patients. The values of PetCO2 and PaCO2 were （ 34. 8 ±7. 6） mm Hg and （40. 6 ± 8. 3 ） mm Hg, respectively. PetCO2 and PaCO2 values were highly positively correlated （ r = 0. 92,P 〈 0. 000 1 ）. Conclusion Noninvasive bedside measurement of PetCO2 in children with acute asthma in emergency department is feasible. Continuous PetCO2 monitoring can provide a reliable assessment of pulmonary status. PetCO2 can serve as an important adjunct index in the clinical management of pediatric patients with acute asthma.