ABSTRACT
BACKGROUND: The genicular arteries (GAs) can be utilized for genicular nerve block. We aimed to evaluate the ability to localize GAs under ultrasound in patients with chronic knee pain. METHODS: Twenty-four knees from 14 osteoarthritic patients were enrolled. The target GAs included the superomedial GA (SMGA), superolateral GA (SLGA), and inferomedial GA (IMGA). GAs were observed at the relevant adductor tubercle and epicondyle-shaft transition under ultrasound. Distribution of the SMGA at the adductor tubercle was evaluated using defined zones in transverse and longitudinal ultrasound images. SLGA and IMGA were also categorized using defined zones in longitudinal images. Distance from bony cortex to the relevant GA was then estimated. RESULTS: Among 24 knees, 91.7% of SMGAs were located at the upper part of the adductor tubercle. The distances between the SMGA and bony cortex on transverse view (dSMGAt) and on longitudinal view (dSMGAl) were directly correlated (rs = 0.6539, P = 0.0005). CONCLUSIONS: Under ultrasound guidance, the SMGA was found to be mainly localized to the upper part of the adductor tubercle. Likewise, the SLGA and IMGA were mainly localized at the distal and proximal parts of the epicondyle-shaft transition, respectively. Our results support the feasibility of ultrasound guidance for GA localization in patients with knee osteoarthritis.
Subject(s)
Humans , Arteries , Knee , Nerve Block , Osteoarthritis, Knee , UltrasonographyABSTRACT
BACKGROUND: Preemptive analgesia is known to decrease the sensitization of the central nervous system and reduce subsequent amplification of nociceptive stimuli. We investigated whether preemptive thoracic epidural analgesia (TEA) demonstrated intraoperative and postoperative short and long term clinical advantages. METHODS: Thirty patients scheduled for open thoracotomy were randomly allocated to one of two groups to receive continuous TEA (0.15% bupivacaine and 8 microg/ml hydromorphone) either before surgical incision (preemptive group) or at the end of the operation (nonpreemptive group). Incidence of hypotension during surgery was recorded. Numerical rating scales (NRS) and the incidence of side effects such as nausea, pruritus, sedation, hypotension, and respiratory depression were recorded at 2, 6, 24, and 48 hours postoperatively. Pulmonary function test (PFT) was performed before, 24 and 48 hours after the operation. Persistence of pain control was investigated at 6 months postoperatively. RESULTS: The NRS score, side effects, and PFT changes were comparable between the two groups. TEA and intravenous rescue morphine consumed at 2, 6, 24, and 48 hours postoperatively were not different between the two groups. During surgery, the incidence of hypotension was significantly higher in the preemptive group (P = 0.027). At 6-month follow up, two patients in the nonpreemptive group complained of persistent pain at wound and none in the preemptive group. CONCLUSIONS: Preemptive TEA with hydromorphone and bupivacaine during surgery may cause unnecessary intraoperative hypotension without a prominent advantage in reducing acute or chronic pain or enhancing pulmonary function after thoracotomy. The advantageous concept of preemptive TEA may be dubious and may not provide perioperative clinical benefits.