男,34歲,燒傷后3小時(shí)入院,呼吸深大,吸氧5L/min,查血?dú)馐緋H7.35、PaO2137.2mmHg、PaCO210.5mmHg、BE–16.8mmol/L、[HCO3-]5.7mmol/L,其診斷為()