急性Ⅱ型呼吸衰竭是危重病人死亡的重要原因之一。急性呼吸衰竭是由于呼吸中枢和(或)呼吸器官的原发或继发病变引起的急性通气和(或)换气功能障碍,导致缺氧和二氧化碳潴留以及一系列代谢功能紊乱的临床综合征。临床表现患儿可有呼吸困难、紫绀、烦躁、心率加快等征症。动脉血气分析示动脉氧分压(PaO_2)<50 mm Hg和动脉血二氧化碳分压(PaCO_2)>50 mm Hg。凡具备以上二条者诊断为急性Ⅱ型呼吸衰竭并被选入本组试验中。据 Acute type Ⅱ respiratory failure is one of the important causes of death of critically ill patients. Acute respiratory failure is a clinical syndrome of acute ventilation and / or ventilatory dysfunction due to the primary or secondary lesion of the respiratory and / or respiratory organs leading to hypoxia and carbon dioxide retention as well as a series of metabolic disorders. Children with clinical manifestations may have dyspnea, cyanosis, irritability, heart rate and other symptoms. Arterial blood gas analysis showed PaO_2 <50 mm Hg and PaCO_2> 50 mm Hg. Where more than two have been diagnosed as acute type Ⅱ respiratory failure and was elected to the group test. according to