海平面室内空气:PaCO₂=40,FiO₂=0.21 → PAO₂ ≈ 99.7 PAO₂ = 0.21×(760−47) − 40/0.8 = 149.73 − 50 = 99.73 mmHg。即教科书所述的海平面室内空气预期 ~100 mmHg。{"result":"Alveolar Gas Equation: PAO₂ = 0.21 × (760 − 47) − 40 / 0.8 = 99.7 mmHg.","metadata":{"input":{"paco2":40,"fio2":0.21,"patm":760,"rq":0.8},"result":{"pao2Alveolar":99.7,"fio2":0.21,"patm":760,"rq":0.8,"pH2O":47,"category":"Normal PAO₂ (sea level, room air)","method":"PAO₂ = FiO₂ × (P_atm − 47) − PaCO₂ / RQ","model":"StatPearls NBK545153; LITFL; Cornell PICU; West. Not medical advice."}}}
高海拔(丹佛):PaCO₂=35,FiO₂=0.21,P_atm=630 → PAO₂ ≈ 78.7 PAO₂ = 0.21×(630−47) − 35/0.8 = 122.43 − 43.75 = 78.68 mmHg。高海拔低压使 PAO₂ 降低——此处 PaO₂ 下降可由海拔解释,而非肺部疾病;过度通气(低 PaCO₂)部分代偿。{"result":"Alveolar Gas Equation: PAO₂ = 0.21 × (630 − 47) − 35 / 0.8 = 78.7 mmHg.","metadata":{"input":{"paco2":35,"fio2":0.21,"patm":630,"rq":0.8},"result":{"pao2Alveolar":78.7,"fio2":0.21,"patm":630,"rq":0.8,"pH2O":47,"category":"Reduced PAO₂ due to altitude","method":"PAO₂ = FiO₂ × (P_atm − 47) − PaCO₂ / RQ","model":"StatPearls NBK545153; LITFL; Cornell PICU; West. Not medical advice."}}}