Perioperative analgesia refers to pain management strategies implemented before, during, and after surgery to reduce pain, improve recovery, and minimize complications. It is a critical component of multimodal perioperative care, especially in enhanced recovery after surgery (ERAS) protocols.

• Prevent and control postoperative pain
• Reduce stress response to surgery
• Facilitate early mobilization and rehabilitation
• Minimize opioid use and related side effects
• Improve overall surgical outcomes

• Patient education and expectation setting
• Pre-emptive analgesia: analgesics *before incision* (e.g. paracetamol, NSAIDs, gabapentinoids)
• Optimization of comorbidities (e.g. renal function, anticoagulation)

• Regional anesthesia: spinal, epidural, nerve blocks (e.g. scalp block, TAP block)
• Systemic analgesics: opioids, NSAIDs, paracetamol, ketamine, lidocaine infusion
• Adjuvants: clonidine, dexmedetomidine, magnesium sulfate

• Multimodal analgesia: combining different drug classes (e.g. paracetamol + NSAID + low-dose opioid)
• Patient-controlled analgesia (PCA)
• Continuation of regional techniques: epidural infusion, nerve catheter
• Non-pharmacological methods: cold therapy, physical therapy

This is the cornerstone of effective perioperative pain management:

• Opioid-sparing techniques
• Use of regional blocks and non-opioid drugs
• Reduces opioid-related side effects: nausea, sedation, ileus

• Type and extent of surgery (minor vs. major)
• Patient factors: age, renal/hepatic function, opioid tolerance
• Risk of chronic post-surgical pain
• Avoiding drug interactions and adverse effects

In craniotomies, scalp nerve blocks using bupivacaine ± clonidine can:

• Reduce intraoperative hemodynamic fluctuations
• Provide postoperative analgesia
• Reduce opioid requirements