Inclusion Criteria:  18< age < 75 years; ASA physical state I and II; .Undergoing percutaneous radiofrequency ablation.  Exclusion Criteria:  Age < 18 years or older than 75 years; America Society of Anesthesiologists (ASA) class >III; Allergic to anesthetic solutions; Tendency for nose bleeding or coagulation disorders; Local infection (eg. mouth, nose, or throat infection); Heart disease like congestive heart failure, severe aortic stenosis or mitral stenosis, cardiac surgery involving thoracotomy (eg, coronary artery bypass graft or valve replacement surgery) in the last 6 months; acute myocardial infarction in the last 6 months; acute arrhythmia (including tachycardia and bradycardia) with hemodynamic instability; Diagnosed chronic obstructive pulmonary disease (COPD) or other current acute or chronic lung diseases requiring supplemental chronic or intermittent oxygen therapy; Increased intracranial pressure; Fever, defined as core body temperature >37.5 C; Severe anemia (30g/L< hemoglobin <6g/L); Emergency surgery; Patients refuse to participate;