Comparative evaluation of analgesic effect of ultrasound guided superficial cervial plexus block in mastoid surgeries.

Mastoid surgeries are one of the commonest ear surgeries performed globally. Tradi8onally these surgeries are performed under general anaesthesia and have several issues like risk of post opera8ve pain and PONV. For pain management intraopera8vely and postopera8vely opioids are the mainstay, however opioids have their own problems like postopera8ve respiratory depression, hypoxia and nausea vomi8ng. With development of mul8modal analgesia, various blocks have been advocated for beDer post opera8ve pain management like SCPB. However, there are limited studies enumera8ng the effect of superficial cervical plexus block (SCPB) in mastoid surgeries. The limita8on of SCPB is dura8on of analgesia so various aDempts have been made to increase the dura8on by adding adjuvant medica8on. Dexamethasone is a popular adjuvant for peripheral nerve blocks but these studies are mostly related to brachial plexus blocks. There is one study of use of dexamethasone in SCPB in thyroid surgeries where it has shown beDer pain control in the post opera8ve period. But we could not find any study of SCPB in which dexamethasone has been used in mastoid surgery.

The primary objec8ve of the study is to observe the dura8on of analgesia which will be assessed by the 8me of the first dose of rescue analgesia if VAS score is greater than four. The secondary objec8ves will be to see the total analgesic consump8on, hemodynamic parameters intraopera8vely and postopera8vely and the incidence of post opera8ve nausea and vomi8ng (PONV). Following approval from the ins8tu8onal ethics commiDee and registering the trial at CTRI, a wriDen informed consent will be obtained from the pa8ents. The study will be done for a period of 18 months. Pa8ents will undergo preanaesthe8c checkup a night before surgery. General anaesthesia with endotracheal tube inser8on (midazolam/fentanyl/propofol/vecuronium) will be done. Pa8ents will be divided in two groups.

Group B- 8ml(0.25%) bupivacaine Group D-8ml(0.25%)bupivacaine +2ml normal saline +2ml dexamethasone

The pa8ent will be in supine posi8on with the ipsilateral shoulder on the side of block propped up and the head turned to contralateral side. The site of interest will be painted and draped with the superficial cervical plexus block being placed in all asep8c precau8ons with a high frequency linear ultrasound probe (5-13 MHz). At the end during skin suturing all pa8ents will receive i.v ondansetron and paracetamol 1gm i.v. The residual neuromuscular blockade will be reversed a_er the pa8ent is fully responsive and awake.The pa8ent will be then shi_ed to post opera8ve care unit (PACU) for observa8on and monitoring. All the pa8ents will receive i.v paracetamol 1g/8 hourly in the postopera8ve period. Rescue analgesic will be provided with diclofenac 75mg in 100ml normal saline slow I.V over 30 minutes if the VAS score is greater than 4. All pa8ents will be monitored for the first dose of rescue analgesia, total dose of rescue analgesia consump8on, nausea vomi8ng and adverse events in the post operative period.