**2.2 Regional anesthesia**

RA of the upper extremity is primarily achieved through a brachial plexus block. RA offers many advantages over other anesthetic methods, including intraoperative hemodynamic stability and good postoperative analgesia. There is also evidence that it improves vascular flow via regional sympathectomy, although evidence of improved graft survival is lacking yet [6–8]. There are several ways to perform a brachial plexus block, including supraclavicular or infraclavicular and axillary approaches. Complications of RA include infection, hematoma, local anesthetic toxicity, and nerve injury. There are also complications that are specific to each approach, such as total spinal anesthesia, Horner syndrome, hemi diaphragmatic paralysis, and pneumothorax during supraclavicular blocks. There is not enough published data, but the use of ultrasound-guided nerve blocks certainly appears to have made these blocks easy and decreased the incidence of complications [9]. It should be noted that following a brachial plexus block supplementation with LA by the surgeon may be required and LA dose calculations are to be kept in mind to avoid local anesthetic toxicity.

*Anesthetic Management of Surgical Vascular Access for Hemodialysis DOI: http://dx.doi.org/10.5772/intechopen.109844*

#### *2.2.1 Supraclavicular block*

The supraclavicular block is performed around the brachial plexus and passes with the subclavian artery, which is an exceptionally good anatomical landmark. The subclavian artery crosses over the first rib between the insertions of the anterior and middle scalene muscles, posterior to the midpoint of the clavicle. A high frequency (10–15 MHz) ultrasound beam due to the superficial location of the brachial plexus at this level should be used to improve the quality of visualization of all structures in this area. The subclavian artery is readily apparent as an anechoic round structure, while the parietal pleura and the first rib can be seen as a linear hyperechoic structure immediately lateral and deep to the subclavian artery. Supraclavicular brachial plexus can be visualized slightly superficial and posterolateral to the subclavian artery. Local anesthetic solution is given over the trunks of the brachial plexus above the formation of musculocutaneous and axillary nerves [10]. The supraclavicular block is preferred in many institutes because the brachial plexus is tightly packed at this level allowing for an intensive block. Also, this block provides adequate anesthesia for the entire arm and allows for surgical site flexibility. The major disadvantage is relatively higher risk for pneumothorax due to its proximity to the pleura, but it can be overcome with use of ultrasound technique. Also, phrenic nerve blockade is likely (reported up to 50% incidence) with this approach and close observation should be performed especially in patients with compromised respiratory function. The supraclavicular block should be avoided in patients who are unable to withstand up to 30% reduction in pulmonary function resulting from ipsilateral phrenic nerve block.

### *2.2.2 Infraclavicular block*

The infraclavicular block is performed around the brachial plexus, which is below the level of the clavicle and in proximity to the coracoid process. Local anesthetic solution is deposited over the cords of the brachial plexus, which lie circumferentially around the artery at this level. This block is indicated for distal arm surgery at the elbow, forearm, and hand. Due to the relatively deep location of the brachial plexus at this level, lower frequency of ultrasound beam (5–12 MHz) is helpful for better tissue visualization, especially in obese patients whose plexus is extremely deep [11]. Maneuvers to decrease the depth of the target may be worth trying for success. Some patients may feel uncomfortable with this block since the needle should penetrate through the thicker muscles such as pectoralis major and minor. The patients may require more sedation, which may be respiratory depression or apnea. It should be noted that supplementation of LA provided by the surgeon, additional sedation, or conversion to general endotracheal anesthesia may be required if additional high surgical approach of forearm is needed. In some institutes, this block is considered as an alternate for supraclavicular when there is a relative contraindication to supraclavicular block (e.g., subclavian artery pathology or arteriovenous communication around the trunks, which makes it difficult to pass the needle without puncturing the vessels; severe chronic obstructive pulmonary disease).

#### *2.2.3 Axillary block*

The axillary block performed under ultrasound guidance is highly recommended and successful. Due to the superficial location of the brachial plexus, high-frequency ultrasound beam (10–15 MHz) can provide an excellent visualization of all structures where local anesthetics are injected. The axillary artery is a very good landmark to find the spot to find location of the median, ulnar, radial, and median nerves. An additional block of the musculocutaneous nerve off the axillary artery is required to achieve complete analgesia for distal arm. However, it should be noted that there are significant variations between the anatomical positions of the nerves relative to the axillary artery [12]. More analgesic effect is achieved by multiple injections rather than a single injection for axillary approach. Retzl and colleagues observed that the position of the nerves relative to the axillary artery at this level changes significantly with application of varying pressures [13].

#### **2.3 General anesthesia**

Almost all patients with CKD and ESRD have multiple comorbid risk factors for GA due to the nature of the conditions that led to the renal insufficiency. Previous clinical research has reported that approximately 25% of the patients who undergo renal replacement therapy have ischemic heart disease, 10% have cerebrovascular disease, and 12% have peripheral vascular disease [14]. Therefore, anesthesiologists consider avoiding GA, if possible, but this may not always be feasible for patients with a history of psychological disorders or those who need more complicated procedures, such as an upper arm transposition or AVG, which may not be amenable to RA. Modes of GA delivery include endotracheal tube (GETA) and laryngeal mask (LMA). There are some advantages of GETA over LMA. GETA provides a more secure airway and controls PaCO2 easily. It results in minimal aspiration risk and avoids respiratory acidosis that can contribute to increase the potassium level rapidly. However, usage of LMA does not require muscle relaxants, which can delay emergence from GA at the conclusion of the case.

During anesthesia induction, hemodynamics should be maintained with titrating doses of inductions agents such as propofol and prompt use of narcotics. However, blood pressure tends to decrease significantly after induction due to lower vascular compliance and/or lower cardiac reserve function. In these cases, a bolus or a continuous infusion of vasoactive medications such as ephedrine and phenylephrine intravenously should be initiated at the same time as general anesthesia induction to keep the perfusion pressure adequate. Also, selection for induction drugs such as etomidate or midazolam combined with fentanyl, which do not decrease blood pressure as much as propofol, may be a good idea. As to pain control during the surgery, the use of LA by the surgeon can contribute to reducing the intraoperative use of inhalational anesthetics and narcotics.
