|Brachial plexus block is a regional anaesthesia technique employed as a safe and valuable alternative to general anaesthesia for upper limb surgery. In recent practices of day care surgeries, brachial plexus block seems to be a better alternative to general anesthesia with minimal hospital stay and better analgesic effect. Among several techniques of brachial plexus block, supraclavicular approach is considered as easiest, effective and can be performed much more quickly than other approaches. Various local anaesthetic agents and adjuvants are used for this purpose. Among them, bupivacaine has been the most widely used long-acting local anaesthetic agent. Combining local anesthetics with different adjuncts can prolong the duration of analgesia associated with brachial plexus block. Among various adjuncts, dexamethasone and dexmedetomidine have been identified as clinically effective adjuncts. Several metaanalyses have convincingly demonstrated their efficacy in prolonging the analgesic duration of brachial plexus block. However, there has been limited research conducted to compare the effects of dexamethasone and dexmedetomidine added as adjuvants to the local anesthetics for BPB. Studies have demonstrated benefits of one agent over other without any definitive conclusion as which is the best agent for this purpose. Therefore, there is a need of study to compare the onset and duration of bupivacaine when dexmedetomidine or dexamethasone is used as an adjuvant to bupivacaine for ultrasound-guided supraclavicular BPB.|
Principal Investigator ( 1 )
Patient will be transferred to operation theatre. HR, SPO2, SBP, DBP and MAP will be measured on arrival at the Operation Theatre. • Patient will be positioned in the supine position with the arm adducted in the side where brachial plexus block will be administered. The supraclavicular region will be disinfected with aseptic precautions. • An Ultrasound machine (Sonosite Edge ®) will be used. The linear transducer probe (frequency 4 -12 Hz) of USG machine will be placed in the supraclavicular fossa to locate the brachial plexus. A superficial skin wheal will be made by 2ml of 1% lignocaine subcutaneously at the point of needle insertion. USG guided Brachial plexus block will be performed by supraclavicular route via the subclavian perivascular approach in in-plane technique from lateral to medial using 22 gauge spinal needle. Study Drug will be administered via Pressure Monitoring line connected to syringe according to the allocated group with repeated aspiration and incremental dosing. • Intercostobrachial nerve block will be performed to alleviate the tourniquet pain. A 25 G needle will be inserted at the level of axillary fossa. The entire width of the medial aspect of arm, starting at the deltoid prominence and proceeding inferiorly, will be infiltrated with 5ml of 1% Lignocaine with Epinephrine (1:4,00,000) to raise a subcutaneous wheal. • The time of administration of study drug will be noted and will be labelled as “time zero”. • Sensory blockade will be evaluated every 5 mins after injection of study drug for 30 mins or until complete sensory block is achieved, whichever is earlier. • Data collection will be performed by an independent observer who was blinded to the patient’s drug allocation. • The extent of sensory blockade will be tested in the median, radial, ulnar, and musculocutaneous nerve distribution using pinprick: 0 = no perception, 1 = decreased sensation, or 2 = normal sensation. • Successful blockade will be defined as complete sensory blockade (ie, sensory block score = 0) in the distribution of the radial, ulnar, median, and musculocutaneous nerves within 30 mins of performing the BPB. • Motor blockade assessment will be done using the modified Bromage scale for upper extremities on a three-point scale: Grade 0 : Normal motor function with full flexion and extension of elbow, wrist, and fingers Grade 1 : Decreased motor strength with ability to move the fingers only Grade 2 : Complete motor block with inability to move fingers • Motor blockade will be evaluated every 5 mins after injection of study drug for 30 mins or until complete motor block is achieved, whichever is earlier. • Onset time of motor block is defined as minimum of grade 1 of Modified Bromage scale. • In any event of inadequate sensory or motor block after 30 min of injection of study drug, the patient will be given general anesthesia. • Surgery will be commenced after the onset of sensory and motor blocks . • After the end of surgery, patient will be shifted to the Post-Anaesthesia Care Unit. • The patient will be kept under observation for 1 hour to monitor vital signs (conscious level, blood pressure, heart rate, respiratory rate and pattern) then will be discharged to ward. • Study will be continued in ward. • In the ward, sensory and motor blockade will be assessed every 4 hourly from the time of administration of study drug until complete resolution of blockade and it will be recorded. • The time between drug administration and request for first analgesic medication or NRS (numerical rating scale) score more than or equal to 4 will be recorded as duration of analgesia. These patients will be administered Injection fentanyl 0.5mcg/kg iv as rescue analgesia. • NRS score will be assessed every 4 hour after injection of study drug and it will be recorded. • Vital parameters (HR, SBP, DBP, MAP, SpO2) and sedation score (Ramsay Sedation Score) will be recorded from “time zero” and intraoperatively at 15 minutes interval until surgery is completed and then every 4 hourly from the time of administration of study drug until complete resolution of blockade. • Duration of sensory block will be defined as the time interval between the success of the block and the complete resolution of anesthesia (sensory block score = 2) on all nerves area and it will be recorded. • Duration of motor block will be defined as the time interval between the success of the block and the recovery of complete motor function of forearm and hand. • Patients will be questioned for adverse events such as nausea, vomiting, skin rash and observed for any other adverse events such as pneumothorax, Horner’s syndrome, phrenic nerve palsy or respiratory depression intraoperatively and postoperatively.
|Primary Objective: To compare the duration of analgesia between two groups. |
Secondary Objectives: To compare the onset and duration of sensory blockade between two groups.
To compare the onset and duration of motor blockade between two groups.
To assess for adverse events.
|Criteria for sample selection||Inclusion criteria |
1. ASA PS I & II
2. Age: 18-65 years
3. Sex: Both male and female
4. Patients scheduled for Upper limb surgery below the level of midshaft of humerus.
1. Local infection at the site of puncture
2. Patients having any neurologic deficit in the upper limb
3. Pregnant or lactating women.
4. Patients receiving adrenoceptor agonist or antagonist therapy or chronic analgesic therapy.
5. Patients with diabetic neuropathy, peripheral vascular disease, coagulopathy, or known allergies.
6. Patients with polytrauma.
7. Patients weighing <30 kg and > 100 kg.