Adding adjuvant drugs to intrathecal local anaesthetics improves quality and duration of sensory blockade and prolongs postoperative analgesia. Intrathecal opioids are synergistic with local anaesthetics, thereby intensifying the sensory block without increasing sympathetic block. (1) 

In 2016, wahi et al conducted with 30 patients in each group using bupivacaine with clonidine and studied the duration of sensory and motor block and concluded that addition of clonidine to bupivacaine intrathecally is a reliable method to prolong spinal anaesthesia but close monitoring for hypotension was to be noted.(4)

In 2012, safari et al did a study on 90 opium abuser patients were selected and randomly assigned into 3 groups. The patients received  bupivacaine-midazolam and  bupivacaine-fentanyl group; both were longer than the plain bupivacaine group. Therefore midazolam is more effective than fentanyl in such cases.(5)

Minagar et al conducted a study with one hundred patients between fifty patients were randomly allocated to receive dexmedetomidine and Bupivacaine and vital sign parameters were studied and concluded that intrathecal dexmedetomidine increases the duration of analgesia and reduces postoperative pain without changes in the hemodynamic parameters and adverse side effects. It can be considered as an appropriate adjuvant to intrathecal local anaesthetics for lower limb surgeries.(6)

Fernandez et al did a study with forty patients undergoing knee or hip replacement were studied. They received fentanyl with Bupivacaine and Bupivacaine and the results showed that 25 micrograms of spinal fentanyl do not modify spinal anaesthesia in the elderly, but induces pruritus and O2 desaturation. The decrease in postoperative pain intensity and the preservation of cognitive function would justify the use of spinal fentanyl in the elderly.(7)

A prospective, randomized, double-blind, and comparative study was conducted on 150 parturients in 2018 by bindra et al and were randomized into three groups with fifty patients in each group. They received bupivacaine with nalbuphine and bupivacaine with fentanyl and concluded intrathecal nalbuphine prolongs postoperative analgesia maximally and may be used as an alternative to intrathecal fentanyl in cesarean section(8)

There are very few large studies that have compared intrathecal nalbuphine with intrathecal fentanyl added to hyperbaric bupivacaine infra umbilical surgeries. Therefore, we designed a randomized double-blind study to compare the effects of intrathecal nalbuphine and fentanyl as adjuvants to bupivacaine patients undergoing infra umbilical surgeries. The aim of this study was to compare fentanyl with nalbuphine as intrathecal adjuvant to 0.5% hyperbaric bupivacaine in terms of sensory and motor blockade characteristics and duration of postoperative analgesia and hemodynamic changes.