Parecoxib as an Adjuvant to Scalp Nerve Blocks for Relief of Post-craniotomy Pain

Pain is common for the first 2 days after major craniotomy. Inadequate analgesia induced sympathetically mediated hypertension may lead to an increased risk for post-operative complications, such as arterial hypertension, intracranial hemorrhage, prolonged hospital stay, and mortality.Pain after craniotomy derives from the scalp and pericranial muscles.Scalp block with local anesthesia seems to provide effective and safe anesthetic management.Scalp block can be performed by directly blocking the six different nerves that provide the sensory innervation of the scalp in neurological surgery.Even if adrenaline as an additive agent, scalp block using 0.5% or 0.75% bupivacaine with adrenaline could only improve postoperative analgesic for up to six hours after craniotomy.However, pain is common for the first 2 days after major elective intracranial surgery, and the relatively short analgesic time of scalp nerve blocks does not seem to meet the requirements of craniotomy. Therefore, how to improve the quality and duration of scalp nerve blocks with local anesthetics is of great significance.Parecoxib is a NSAIDs that specifically inhibits the enzyme COX-2.Liu et al firstly applied parecoxib as an adjuvant to local anesthetics on peripheral nerve blocks and reported 20 mg parecoxib added to ropivacaine injected locally on the brachial plexus nerve prolonged the motor and sensory block times of the nerve blockade and ameliorated postoperative pain intensity for patients receiving forearm orthopaedic surgery. However, there has not been reported about local application of parecoxib on scalp nerve blocks. The investigators postulate that parecoxib may be also ideal for scalp nerve blocks for relief of post-craniotomy pain, and further research is needed. The APONIA trial aims to establish whether scalp blocks with a mixture of ropivacaine plus parecoxib is able to relieve patients' postoperative pain compared with local anesthetics alone, thereby potentially changing medical