Pre-emptive Scalp Infiltration With Dexamethasone Plus Ropivacaine for Postoperative Pain After Craniotomy

Exclusion Criteria

• •History of craniotomy;
• •Expected delayed extubation or no plan to extubate;
• •Participants who cannot use a patient-controlled analgesia (PCA) device;
• •Participants who cannot understand the instructions of a numeral rating scale (NRS) 35 before surgery;
• •Extreme body mass index (BMI) (\< 15 or \> 35);
• •Allergy to opioids, dexamethasone or ropivacaine;
• •History of excessive alcohol or drug abuse, chronic opioid use (more than 2 weeks), or use of drugs with confirmed or suspected sedative or analgesic effects;
• •History of psychiatric disorders, uncontrolled epilepsy or chronic headache;
• •Pregnant or at breastfeeding;
• •Symptomatic cardiopulmonary, renal, or liver dysfunction or history of diabetes;
• •Preoperative Glasgow Coma Scale\< 15;
• •Suspicion of intracranial hypertension;
• •Peri-incisional infection;
• •Participants who have received radiation therapy and chemotherapy preoperatively or with a high probability to require a postoperative radiation therapy and chemotherapy according to the preoperative imaging.