The Effect of Dexmedetomidine on Postoperative Opioid Consumption and Pain After Major Spine Surgery.

BACKGROUND: Adult deformity correction spine surgery can be associated with significant perioperative pain because of inflammatory, muscular, neuropathic, and postsurgical pain. α-2 Agonists have intrinsic antinociceptive and antihyperalgesic properties that can potentially reduce both postoperative opioid consumption and pain. We hypothesized that intraoperative dexmedetomidine would reduce postoperative opioid consumption and improve pain scores in deformity correction spine surgery. METHODS: Patients undergoing >3 levels of thoracic and/or lumbar spine surgery were enrolled in this prospective randomized double-blind study to receive either dexmedetomidine (1 µg/kg load followed by a continuous infusion of 0.5 µg/kg/h) or saline. Both groups received a single dose of 0.2 mg/kg (ideal body weight) of methadone at the start of surgery. Intraoperative fentanyl was administered based on the clinical and hemodynamic signs suggestive of increased nociception. Postoperative analgesia was provided with a hydromorphone patient-controlled analgesia pump. Opioid consumption and pain scores were recorded at 24, 48, and 72 hours after surgery. RESULTS: One hundred forty-two participants were enrolled with 131 completing the study. There was no significant difference in demographics (age, sex, weight, and ASA physical status), percentage of participants with preoperative opioid use, and daily median opioid consumption between the groups. The study was terminated early after interim analysis. Intraoperative opioid use was reduced in the dexmedetomidine arm (placebo versus dexmedetomidine, median [25%-75% interquartile range]: 7 [3-15] vs 3.5 [0-11] mg morphine equivalents, P = 0.04) but not at 24 hours: 49 (30-78) vs 61 (34-77) mg morphine equivalents, P = 0.65, or 48 hours: 41 (28-68) vs 40 (23-64) mg morphine equivalents, P = 0.60, or 72 hours: 29 (15-59) vs 30 (14-46) mg morphine equivalents, P = 0.58. The Wilcoxon-Mann-Whitney odds are 1.11 with 97.06% confidence interval (0.71-1.76) for opioid consumption. No difference in pain score, as measured by the 11-point visual analog scale, was seen at 24 hours (placebo versus dexmedetomidine, median [25%-75% interquartile range]: 7 [5-7] vs 6 [4-7], P = 0.12) and 48 hours (5 [3-7] vs 5 [3-6], P = 0.65). There was an increased incidence of bradycardia (placebo: 37% vs dexmedetomidine: 59% P = 0.02) and phenylephrine use in the dexmedetomidine group (placebo: 59% versus dexmedetomidine: 78%, P = 0.03). CONCLUSIONS: Intraoperative dexmedetomidine does not reduce postoperative opioid consumption or improve pain scores after multilevel deformity correction spine surgery.

Accuracy of medial foot compartment pressure testing: a comparison of two techniques.

BACKGROUND: Foot compartment syndrome is diagnosed with intracompartmental pressure measurements. The purpose of this study was to determine the ability of two techniques to accurately place a needle tip within the medial foot compartment and to compare the proximity of the needle tip to the medial foot compartment neurovascular structures between the two techniques. MATERIALS AND METHODS: This was a laboratory study using ten unembalmed cadaveric ankle-foot specimens. Two 18-gauge side-ported needles were placed into the medial foot compartments of each cadaveric specimen utilizing two separate techniques (Mollica and Reach techniques). Ultrasound was used to confirm needle tip placement within the medial foot compartment and needle proximity to the neurovascular structures. RESULTS: Both needle placement techniques accurately placed the needle tip within the medial foot compartment. However, the distance between the needle tip and the neurovascular structures of the medial foot compartment was significantly closer (p = 0.037) using the Mollica technique (mean = 3.9 mm ± 2.2 mm) than the Reach technique (mean = 10.9 mm ± 5.2 mm). Neither needle placement technique perforated the medial foot neurovascular structures. CONCLUSION: While both medial foot compartment pressure techniques accurately placed the needle tip within the medial foot compartment, the needle tip was significantly further from the medial foot neurovascular structures using the Reach technique than the Mollica technique. The Reach technique involves inserting the needle 6 cm below the distal tip of the medial malleolus, and advancing it 1 cm in a medial to lateral direction.