INTRODUCTION

Postoperative pain relief is an essential component of modern anaesthesia practice that greatly reduces the stress response of surgery and the perioperative morbidity in surgical patients. With the greater availability of portable ultrasound (USG) in recent years, a surge in the use of regional blocks for management of postoperative pain is evident. The use of USG guidance allows real-time visualisation of anatomical structures and shows the spread of anaesthetic solution injected. This is an attractive option in paediatric patients as most regional anaesthetic techniques are performed while under general anaesthesia. Evidence-based literature shows that USG guided regional blocks provide better postoperative pain control, reduce opioid requirements, decrease hospital stay and improve outcomes in paediatric patients¹. Therefore, USG guided regional blocks are becoming the standard of care for postoperative pain relief in paediatric patients².

 Peripheral nerve blocks are usually favoured over central neuraxial blocks as they cause minimal haemodynamic alterations and complications, as well as short hospital stay.  The transversus abdominis plane (TAP) block is one of the most popular peripheral nerve blocks and provides adequate postoperative analgesia for a range of abdominal procedures by blocking the lower intercostal (T6-11) nerves, ilioinguinal, and iliohypogastric nerves^3,4. Local anaesthetic agents (LA) are deposited in the neurovascular plane between the internal oblique and transversus abdominis muscle. The transversus abdominis plane block has been given with LAs like bupivacaine and ropivacaine but they have a limited duration of action^. Adjuvant drugs are often added to LAs in peripheral blocks to achieve a quick, dense and prolonged block⁵. Alpha 2 agonists, like clonidine and dexmedetomidine are commonly added to LAs in TAP block⁶. Their clinical use is however limited by the occurrence of hypotension and bradycardia which can be detrimental in small children in the postoperative period. Dexamethasone, a very potent and highly selective glucocorticoid has also been used an adjuvant to LAs in various nerve blocks resulting in a prolonged duration of analgesia and motor block. Dexamethasone helps by attenuating the release of inflammatory mediators, reducing ectopic neuronal discharge and inhibiting potassium channel-mediated discharge of nociceptive C-fibres. Addition of steroids to LAs effectively and significantly prolongs the duration of analgesia as well as producing earlier onset of action⁷.

                                     RATIONALE FOR STUDY

Transversus abdominis plane block has emerged as a safe, reliable and efficient technique to provide postoperative analgesia for a range of abdominal procedures. Although many studies have described the successful usage of TAP block and the use of adjuncts for the same in adults, no data is available regarding the use of adjuncts such as dexamethasone or clonidine in TAP block in paediatric patients. Thus, the present study is aimed to compare the efficacy (in terms of duration of postoperative analgesia) of clonidine with dexamethasone as an adjunct in ultrasound guided TAP block in children undergoing laparotomy.