A Curved Block Needle for the Infraclavicular Brachial Plexus Block

Sometimes, there is a limited block needle access at the inferior edge of the clavicle while performing in- plane infraclavicular parasagittal blockade. This might present a challenge in manipulating and visualizing the block needle in easy way along its entire trajectory during the blockade. The curved block needle might have its positive impact on the capacity to control the block needle advancement relative to the target nerve.

70 patients between the ages of 18 and 60 years with American Society of Anesthesiologists (ASA) physical status I- II, scheduled for elective surgery distal to the elbow will be enrolled in a prospective, comparative, randomized clinical study.

Patients will be randomly assigned into two groups: C (n = 35), in whom US-guided single injection ICNB will be performed using a curved line needle; and S (n = 35), in whom US-guided ICNB will be performed using a straight line needle. All patients will be pre-medicated with oral diazepam (7.5 mg) 30 min before the procedure, and IV fentanyl (50 ug) will be administered 5 minutes before placement of the block. Before the procedure, an IV access and standard monitoring of electrocardiogram (ECG), noninvasive blood pressure (NIBP), and peripheral oxygen saturation (SPO2) will be established.

The ultrasound guided Infraclavicular brachial plexus block will be performed in the block room using a linear-array US probe (8-13 MHz). The ultrasound probe will be placed just below the lower edge of the clavicle and medial to the coracoid process (parasagittal orientation), with adjustment of depth, frequency and gain to spot the best view of the transverse axillary artery and its surrounding cords (short-axis view).

After sterile skin preparation with chlorhexidine solution, local infiltration with 2 ml of lidocaine (10 mg/ml) will be made at the cephalad aspect of the ultrasound probe. A 10-cm, short-bevel block (straight or curved) needle will be attached to the nerve stimulator delivering a current of 1.2 mA ( milliampere) at a frequency of 2 Hz (Hertz), will be inserted in-plane just inferior to the clavicle.

After eliciting the posterior cord motor response (finger or wrist extension) with a current intensity of ≤ 0.5 mA, correct needle-tip position will be confirmed by test injections with 1 ml of 5 % dextrose solution. Then, thirty milliliters of local anesthetic mixture (lidocaine 10 mg/ml and bupivacaine 2.5 mg/ml) will be incrementally injected after careful aspiration. The goal is to ensuring a U-shaped distribution of anaesthetic solution with anterior displacement of the axillary artery.

Inclusion criteria

• 18 - 60 year old both sex, able to provide informed consent to participate, enrolled in elective surgery distal to the elbow, single procedure.

Exclusion criteria

• Unable to consent to participate, known to have lidocaine or bupivacaine allergy, more than one procedure will be performed at the same setting, patients with local infections,neuropathies, coagulopathies,and history of chronic analgesic therapy, Obesity (body mass index ≥ 30 kg/m2),