Yiallouros P K, Milner A D
Division of Paediatrics, United Medical School of Guy's Hospital, University of London, England.
Pediatr Pulmonol. 1994 Jun;17(6):370-7. doi: 10.1002/ppul.1950170606.
In children with acute obstructive lung disease gas exchange is affected by ventilation-perfusion mismatch and the degree of bronchoconstriction. Standard lung function measurements do not reflect the impairment in gas exchange. Alternatively, the effective pulmonary blood flow (EPBF), that is, the proportion of the cardiac output that is supplying well-ventilated lung units, can give accurate and noninvasive estimates of ventilation-perfusion mismatch. We measured EPBF with the argon freon-22 rebreathing technique in children with acute severe asthma to assess their response to nebulized salbutamol and to determine whether induced changes in the EPBF could be predicted from baseline measurements. Twenty-four children admitted with an acute asthma attack had spirometry and triplicate EPBF measurements before and after nebulized salbutamol. Eighteen patients had repeated tests 50 days later when fully recovered; 4 patients were taking methylxanthines on at least one occasion. The mean forced expiratory volume in 1 sec (FEV1) rose from 55% of predicted to 66% after salbutamol and to 83% with recovery. The mean coefficients of variation for EPBF measurements on the three test occasions were 11.3%, 8.2%, and 9%. Except in children on methylxanthines, the EPBF values were reduced during the acute asthma attack (median, 2.53 L/min/m2; range, 1.99-3.60 L/min/m2) compared with paired values obtained after recovery (median, 2.89 L/min/m2; range, 2.28-4.04 L/min/m2) (P = 0.009). Salbutamol caused a highly significant increase in EPBF from 2.88 L/min/m2 (range, 1.86-3.80) before treatment to 3.34 L/min/m2 (range, 2.26-4.65) immediately afterwards (P = 0.0003).(ABSTRACT TRUNCATED AT 250 WORDS)
在患有急性阻塞性肺疾病的儿童中，气体交换受到通气-灌注不匹配和支气管收缩程度的影响。标准肺功能测量不能反映气体交换受损情况。相反，有效肺血流量（EPBF），即供应通气良好肺单位的心输出量比例，能够准确且无创地评估通气-灌注不匹配。我们采用氩-氟利昂-22再呼吸技术测量急性重症哮喘儿童的EPBF，以评估他们对雾化沙丁胺醇的反应，并确定能否根据基线测量预测EPBF的诱导变化。24名因急性哮喘发作入院的儿童在雾化沙丁胺醇前后进行了肺活量测定和三次EPBF测量。18名患者在50天后完全康复时进行了重复测试；4名患者至少有一次服用了甲基黄嘌呤。吸入沙丁胺醇后，平均1秒用力呼气量（FEV1）从预测值的55%升至66%，康复后升至83%。三次测试时EPBF测量的平均变异系数分别为11.3%、8.2%和9%。除服用甲基黄嘌呤的儿童外，与康复后配对值相比，急性哮喘发作期间EPBF值降低（中位数为2.53 L/min/m²；范围为1.99 - 3.60 L/min/m²）（中位数为2.89 L/min/m²；范围为2.28 - 4.04 L/min/m²）（P = 0.009）。沙丁胺醇使EPBF从治疗前的2.88 L/min/m²（范围为1.86 - 3.80）显著增加至治疗后立即的3.34 L/min/m²（范围为2.26 - 4.65）（P = 0.0003）。（摘要截断于250字）
