2.3. Ultrasound-Guided CPVB
hypoalgesia, hypothermia, NRS, reflux
REFLUX
In the CPVB group, ultrasound-guided CPVB was performed with the patient in the lateral position by the same anesthesiologist at the end of the operation. After identifying the paravertebral space of the proposed level of the intercostal skin incision, a 20-gauge catheter (B. Braun Melsungen AG, 34209 Melsungen, Germany) was inserted 2-3 cm into the paravertebral space by using an out-of-plane approach with an 18-gauge Tuohy cannula needle. When there was no blood or cerebrospinal fluid reflux after suction, a bolus of 1-2 ml of saline solution was injected through the PVB catheter to confirm the correct position, and then, 15 ml of 0.33% ropivacaine was given (Before skin closure, the same surgeon placed two multiperforated wound catheters (PAINfusor®, Baxter, Maurepas, France) between the serratus anterior and the intercostal external in the CWI group. The catheter was inserted three to four centimeters from the incision and sutured to the skin (After the surgery, acupuncture hypoalgesia and hypothermia tests were used to confirm whether the dermatomal level of sensory blockade had reached the fourth thoracic vertebra by 4 hours postoperatively, and patients with failed blockade were excluded. For rescue analgesia, dezocine (10 mg) was given intravenously immediately when NRS exceeded 4 in the resting state.