例1:女,20天。系第一胎足月顺产,出生时体重3750克,Apgar评分9～10分,生后人工喂养。二天前发现口唇、四肢末梢青紫,渐加重,哭闹时尤甚,不咳、无热。就诊当日伴轻度气急,吃奶少。拟诊断新生儿肺炎,先天性心脏病待排除。用先锋霉素V、丁胺卡那、西地兰及吸氧等治疗未见效。体检除周身青紫外,无其它阳性体征。X线胸片正常,与肺炎诊断不符。详问病史, Example 1: Female, 20 days. Department of full-term first-term birth of fetus, birth weight 3750 grams, Apgar score 9 to 10 points, after giving birth artificial feeding. Two days ago found lips, limbs peripheral purple, gradually heavier, especially when crying, not cough, no heat. On the day of treatment with mild urgency, less milk. To be diagnosed neonatal pneumonia, congenital heart disease to be excluded. With cephalosporins V, amikacin, cedilanid and oxygen treatment is not effective. Physical examination in addition to whole body UV, no other positive signs. X-ray normal, and pneumonia diagnosis does not match. Detailed medical history,