Through the design of RCT study, the preoperative use of drugs (methylprednisolone + dihydroxypropyltheophylline) as intervention measures, the patients undergoing thoracoscopic lobectomy as the main research object, through the comparison of two groups of patients with intraoperative respiratory dynamics index and postoperative complications, to explore a more effective perioperative management method.

Inclusion Criteria:

• 1. After fully understanding the purpose and significance of the trial, the patients voluntarily participated in the trial and signed the informed consent;

  2. The type of operation was general anesthesia and thoracoscopic lobectomy;

  3. Age 18-75 years old, including boundary value, gender is not limited;

  4. BMI 18-26kg / m2;

  5. ASA grade I-II; no mental disorder, normal consciousness, normal communication;

  6. No contraindications of methylprednisolone and dihydroxypropyltheophylline.

Exclusion Criteria:

• 1. There were diseases of immune, endocrine, nervous and mental system before operation, and serious dysfunction of heart, liver and kidney;

  2. Take immunosuppressive drugs and non steroidal anti-inflammatory drugs before operation;

  3. Respiratory tract infection (cough, expectoration, suffocation, etc.) in recent 1 month; pneumonia, bronchitis, etc. on CT;

  4. History of chronic pulmonary disease, including but not limited to asthma, pulmonary abscess, tuberculosis, chronic bronchitis, etc;

  5. FEV1 < 50%;

  6. Oxygen saturation was lower than 90% and airway pressure was higher than 40 cm H20;

  7. Continuous hypotension or hypertension during the operation; intraoperative blood loss > 1000ml;

  8. Allergic to methylprednisolone or dihydroxypropyltheophylline;

  9. There are any other situations that the researchers think are not suitable for inclusion.