Perioperative Effects of Lateral Quadratus Lumborum Block in Percutaneous Transhepatic Cholangiography: Prospective Observational Study

The frequency of non-operating room anesthesia (ADA) applications is increasing and has gained an important place in anesthesia practice. Percutaneous transhepatic cholangiography (PTC) procedures applied in interventional radiology are also examples of ADA. It is frequently applied for both diagnostic and therapeutic purposes in cases where obstruction is observed in the bile ducts for any reason. Providing a balanced and comfortable anesthesia during PTC procedures reduces postoperative complications and increases patient and clinician satisfaction. General anesthesia, sedoanesthesia and regional anesthesia can be applied in PTCs. Due to the perioperative complications and undesirable side effects of general anesthesia, it is not the first choice in PTCs. Sedoanesthesia and regional anesthesia are widely applied in PTCs. Postoperative pain is the most important parameter affecting patient satisfaction in this surgery. Inadequate treatment of postoperative pain can reduce the quality of life and cause chronic pain syndromes. In order to effectively combat pain; regional methods are frequently used in addition to intravenous analgesics. For PTC patients, Erector Spinae Plane Block, Quadratus Lumborum Block (QLB) and Subcostal TAP block can be applied covering the T6-L1 dermatome. Since the pain in PTC patients is of visceral and somatic origin, the one with the highest analgesic efficacy is QLB. 4 different techniques of QLB have been defined in the literature and these techniques are; lateral, posterior, anterior transmuscular and intramuscular. Local anesthetic spread is relatively low in the intramuscular technique, while the risk of complications is high in the transmuscular technique. However, lateral and posterior techniques are not superior to each other, and the experience of the clinician is effective in the selection of the technique. The mechanism of action of QLB depends on ipsilateral paravertebral and epidural local anesthetic spread. There are studies in the literature that QLB is used in trunk and abdominal surgeries; provides effective analgesia and reduces the amount of opioid consumed. Due to all these effects, interest in QLB is increasing and its use is becoming widespread. Lateral QLB application: In the left lateral decubitus position, the curvelinear (5-1 MHz) USG probe is placed in the iliac crest and subcostal area at the level of T8-10. Then, the probe is directed posteriorly and cranially to provide detailed visualization of the anterolateral surface of the vertebral body with the transverse process. The probe is slightly tilted to identify the psoas major, quadratus lumborum and erector spinae muscles. The typical image of these 3 muscles forms a three-leaf 'clover' pattern. With the lateral approach, at the point where the transverse abdominis muscle ends, hydrodissection is performed with 2 cc physiological serum to the lateral side of the quadratus lumborum to confirm the location. Then, a total of 20 cc blocking fluid consisting of 14 cc of 0.5% bupivacaine and 6 cc of 2% lidocaine is injected into this area. The blocking fluid is applied in divided doses of 5 cc with intermittent negative aspiration. In our clinic, multimodal anesthesia/analgesia method is preferred in patients undergoing PTC procedure. Peripheral nerve blocks (for all patients who are suitable and accept) are routinely used together with intravenous analgesic agents. The applied block aims to reduce the amount of opioid consumed perioperatively, faster postoperative recovery, lower postoperative VAS scores, lower postoperative analgesia consumption and earlier mobilization. QLB is routinely applied in suitable patients undergoing PTC. Patients who are subjected to sedoanesthesia and those who are subjected to QLB together with sedoanesthesia will be included in the study. The anesthesiologist who provides the anesthesia management of the patients and the anesthesiologist who monitors the patient's pain will be different individuals.