Evaluation of the effects of Ultrasound guided Supraclavicular brachial plexus block with 0.5% Bupivacaine versus 0.5% Ropivacaine in equal doses on Pulmonary function test in patients undergoing elective upper limb surgeries - A Randomised Controlled Trial

This is a prospective study where after Pre Anaesthetic Checkup the patients will be shifted to the operation theatre complex on call and pre anaesthetic review will be done to check if pre operative orders were followed. Then the patient will be shifted to Pre operative holding area and connected to monitors like pulse oximeter, ECG, non-invasive blood pressure and the baseline hemodynamic parameters and will be recorded.18G IV cannula will be secured on the opposite hand and intravenous fluid Ringer Lactate will be started at 6ml/kg prior to supraclavicular block. The patient in semi recumbent position will be asked to blow after taking a deep breath through the filter mouth piece of the spirometer (Safey Pocket Spirometer, India. Product code no: 1652213) 3 times at 2 minutes gap which will be linked to the Mobile phone using bluetooth. The FVC, FEV1 and PEFR will be recorded and the average (best of the 3 values) of the values will be recorded as the pre block PFT. Ultrasound-guided brachial plexus block will be performed prior to surgery in the pre-operative holding area by an attending anaesthesiologist with formal regional anaesthesia training

The patient will be positioned in supine and the hand will be rested following which the Supraclavicular block with ultrasound guidance will be proceeded. For the procedure, patient will be positioned supine with a small roll beneath the shoulder and head turned to the contralateral side to surgical side. Ultrasonography machine with linear probe (6-14 MHz) will be used. The arm to be blocked will be kept adducted and the hand will be rested over the abdomen. Under strict aseptic precaution, transducer

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will be positioned in the transverse plane immediately proximal to the clavicle, and tilted caudally to obtain cross sectional view of subclavian artery.

The brachial plexus will appear as hypoechoic shadows surrounded by hyperechoic rims, lateral to subclavian artery placed above the first rib, classically described as honeycomb appearance. The subclavian artery is appreciated as pulsatile anechoic structure above first rib. The rib is a hyperechoic structure and it generates a bony shadow while the lung is a specular reflector and therefore a grainy image will be seen below the hyperechoic edge of pleura. Colour doppler can be used to distinguish between vascular and nerve structure.

Needle insertion will be done in Double point injection technique. The 18 G venflon needle will be inserted 1-2 cm lateral to probe using in-plane technique toward plexus from lateral to medial direction. Hydro dissection with 0.5-1 ml of normal saline will be done to increase the acoustic mismatch and for better visualization of needle tip. As the needle reaches the “corner pocket”, formed between the subclavian artery medially and first rib inferiorly. i.e., at 7 o’clock position with respect to subclavian artery, 10 ml of drug volume will be injected following repeated aspirations, then the needle will be slowly withdrawn and directed towards the superolateral aspect of the subclavian artery and remaining 10 ml drug will be injected.

Group A will be given 20 ml of 0.5% Bupivacaine whereas Group B will be given 20ml of 0.5% Ropivacaine.

Post procedure the patient will be asked blow through the spirometer and the PFT will be repeated as mentioned before at 15 minutes, 30 minutes, 4 hours and 6 hours. The sensory blockade will be assessed every 2 minutes for the first 15minutes and every 5 minutes till next 15minutes. The motor block will be assessed every 5 minutes till 30 minutes. The patient will be shifted to the Operation theatre after 30minutes and will be connected to the standard ASA monitor. The sensory blockade will be assessed by the Pin Prick Test with 3point score

The motor blockade will be assessed by the Modified Bromage Scale

During the course of intraoperative time, the Heart rate, SBP, DBP, Oxygen saturation and respiratory rate will be recorded for every 5 minutes for the first 30 minutes and every 30 minutes thereafter till the procedure gets over.

The Hypothesis is that In ultrasound guided supraclavicular brachial plexus block, 0.5% ropivacaine is better than 0.5% bupivacaine in preserving the pulmonary function in patients undergoing elective upper limb surgeries