Comparing the Efficacy and Safety of Ultrasound Guided Supraclavicular Block Combined With Either Intercostobrachialor Pec 11for Creation of Surgical Brachio-basilic Fistula in Chronic Renal Failure Patients on Hemodialysis

• Type of Study: Randomized Prospective trail
• Study Setting: Ain Shams University Hospitals, Cairo, Egypt
• Study Period: 6 months.

Sampling Method: Patients will be subdivided randomly into two groups :

Group (SI) : 25 ml of bupivacaine 0.5 % for us guided supraclavicular block plus 10 ml of lidocaine 2% for us guided intercostobrachial nerve block.

Group(SP) : 25 ml of bupivacaine 0.5 % for us guided supraclavicular block plus10 ml of lidocaine 2% for us guided PECll block.

Study Procedures:

Following local university ethical committee approval, informed consent will be obtained. Details of the anesthetic technique and the study protocol will be fully explained at the preoperative visit, and written consent will be obtained from each patient before inclusion in the study. The patients has to have normal prothrombin (PT) and partial thromboplastin (PTT) times before the procedure.

In the pre-induction room the patients will be taught how to assess their own pain score using the numerical rating scale (NRS) (0-10; 0 = no pain, 10 = worst imaginable pain) .

On arrival at the operating room, standard monitoring will be established with five lead electrocardiogram, non-invasive blood pressure measurement and pulse oximeter. After insertion of a 20-gauge intravenous cannula in the non operated arm, an intravenous crystalloid solution will be administered. Supplemental oxygen will be supplied through nasal cannula. The oxygen flow will be set at 3 L/ min.

Patients will receive 1-2 md midazolam intravenous as premedication before the block. All blocks will be performed by one of the authors, The patients will be randomly allocated to one of the two groups, either supraclavicular-intercostobrachial group(SI Group) ,or the supraclavicular-Pec 11 group(SP Group) .

The patient in SI Group is placed in a semi-sitting position by elevating the head of bed 45 degrees with the patients head turned to the opposite site to be blocked. The skin of the neck and the upper chest and axilla and medial upper arm will be prepared in an aseptic fashion. Ultrasound examination of the supraclavicular area will be performed using a 38-mm high frequency (9-12 MHz) linear array transducer with the in-plane approach, will receive 25 ml of 0.5% bupivacaine in the supraclavicular area ,then the operated arm will be abducted and externally rotated, and the elbow flexed to 90°. Ultrasound examination of the medial upper arm will be performed using a 38-mm high frequency (9-12 MHz) linear array transducer and the intercosto-brachial nerve is identified and blocked using 10 ml of lidocaine 2% . The patient in SP Group will also have supraclavicular block that will be performed in the same way as the previous group and then patient is placed in the supine position with the arm abducted 90 degrees position to receive Peg 11 lock by injecting 10ml of lidocaine 2% between pectoralis minor and serratus anterior at 3rd rib level using a 38-mm high frequency (9-12 MHz) linear array transducer with the in-plane approach. The sensory and motor blocks will be evaluated every 5 min for 30 min or until blocks will be complete. An adequate surgical anesthesia will be defined as a motor score of ≥1 , with an absence of pinprick sensations in the area of all the four terminal nerves.

The zero time for onset of sensory and motor blocks will be the completion of the LA injection. Sensory block assessment (0, no block 1, loss of sensation of pinprick 2, loss of sensation of touch) will be performed in the innervations of the four nerve areas, radial (radial dorsum of the hand), median (thenar eminence), ulnar (hypothenar eminence),and intercostobrachial (medial upper arm) corresponding to the nerve distributions in the forearm and hand using the pinprick test, and will be compared with the same stimulation on the contra-lateral arm. The degree of motor block will be evaluated by thumb abduction (radial nerve), thumb adduction (ulnar nerve), and thumb opposition (median nerve), using a 3-point scale (0 =normal motor function, 1 = decreased motor strength, 2 = complete motor block). The onset times of the sensory block (the time between the end of the LA injection and the total abolition of the pinprick response) and motor block (time between the end of the LA injection and complete motor block) will be recorded for each nerve. Patients who will not achieve satisfactory levels of anesthesia and will need intraoperative local infiltration will be recorded .Patient in whom the block failed and local infiltration is not enough will receive general anesthesia (propofol 2mg/kg plus fentanyl 1ug/kg and atracurium 0.5mg/kg ) with laryngeal mask airway inserted for mechanical ventilation .

Postoperative pain will be assessed by one of the authors using a visual analog scale (0, no pain; 10, worst pain imaginable). Analgesic for the first complain of pain will be standardized and consisted of 500 mg of oral or intravenous paracetamol given for a pain score of 4 of visual analog scale.The time to first analgesic requirement will be also recorded by the same author.

Heart rate, peripheral oxygen saturation, respiratory rate, and blood pressure will be measured before the supraclavicular block and 5, 10, 20, 30, 45, and 60 min after the block and thereafter every 60 min for 2 h postoperatively. University of Michigan Sedation Scale (UMSS) (1, awake and alert; 2, sedated, responding to verbal stimulus; 3, sedated, responding to strong physical stimulus; 4, not arousable) will be measured first as baseline before the block then at the same time points for measuring vital signs post-block .