Analgesic effects and distribution of cutaneous sensory blockade of quadratus lumborum block type 2 and posterior transversus abdominis plane block: an observational comparative study.

BACKGROUND: The posterior transversus abdominis plane block (TAPB) and quadratus lumborum block (QLB) were developed for postoperative pain control after lower abdominal surgery. However, there is little data regarding their effects. Their analgesic effects and the distribution of the cutaneous sensory blockade were observed in patients undergoing laparoscopic gynecologic surgery. METHODS: After an induction of general anesthesia, patients alternately received bilateral ultrasound-guided QLB type 2 (QLB2) or posterior TAPB using 20 ml of 0.375% levobupivacaine on each side. The measurements included visual analogue pain scores (VAS), cutaneous sensory blockade in each dermatome, demands for postoperative analgesics, and complications for up to 48 h after the block. Our primary endpoint was VAS at 24 h after the block. RESULTS: Forty patients completed the study. The VAS at rest was significantly lower after QLB2 than that after TAPB at 48 h, but not at 24 h. Neither group differed in VAS when coughing at any point in time. Postoperative demands for fentanyl and other analgesics also did not differ for either block. The majority of injections produced a cutaneous sensory blockade in the T11 and T12 dermatomes in both groups. The median number of dermatomes blocked was limited to three dermatomes after either block. No severe complication related to either block was observed. CONCLUSIONS: The analgesic effects of QLB2 and posterior TAPB did not differ in patients undergoing laparoscopic gynecologic surgery. The cutaneous sensory blockade produced was limited to three dermatomal levels in the majority of patients. However, these findings need to be confirmed through a larger comparative study.

A prospective, randomized comparison between single- and multiple-injection techniques for ultrasound-guided subgluteal sciatic nerve block.

BACKGROUND: It is believed that local anesthetic injected to obtain circumferential spread around nerves produces a more rapid onset and successful blockade after some ultrasound-guided peripheral nerve blocks. However, evidence demonstrating this point is limited only to the popliteal sciatic nerve block, which is relatively easy to perform by via a high-frequency linear transducer. In the present study, we tested the hypothesis that multiple injections of local anesthetic to make circumferential spread would improve the rate of sensory and motor blocks compared with a single-injection technique for ultrasound-guided subgluteal sciatic nerve block, which is considered a relatively difficult block conducted with a low-frequency, curved-array transducer. METHODS: Ninety patients undergoing knee surgery were divided randomly into 2 groups to receive the ultrasound-guided subgluteal approach to sciatic nerve block with 20 mL of 1.5% mepivacaine with epinephrine. For group M (the multiple-injection technique), the local anesthetic was injected to create circumferential spread around the sciatic nerve without limitation on the number of needle passes. For group S (the single-injection technique), the number of needle passes was limited to 1, and the local anesthetic was injected to create spread along the dorsal surface of the sciatic nerve, during which no adjustment of the needle tip was made. Sensory and motor blockade were assessed in double-blind fashion for 30 minutes after completion of the block. The primary outcome was sensory blockade of all sciatic components tested, including tibial, superficial peroneal, and sural nerves at 30 minutes after injection. RESULTS: Data from 86 patients (43 in each group) were analyzed. Block execution took more time for group M than group S. The proportion of patients with complete sensory blockade of all sciatic components at 30 minutes after injection was significantly larger for group M than group S (41.9% vs 16.3%, P = 0.018). Complete motor blockade of foot and toes extension also was observed more frequently in group M than in group S (67.4% vs 34.9%, P = 0.005 and 51.2% vs 25.6%, P = 0.027, respectively). CONCLUSIONS: When ultrasound-guided subgluteal sciatic nerve block is conducted, multiple injections of local anesthetic to make a circumferential spread around the sciatic nerve improve the rate of sensory and motor blocks compared with a single injection.

[A case report: perioperative management of adenotonsillectomy in a morbidly obese patient with severe obstructive sleep apnea syndrome].

A male patient in his thirties was scheduled to undergo adenotonsillectomy due to dyspnea from bilateral tonsillar hypertrophy. He was morbidly obese (body mass index 56 kg x m(-2)) with severe obstructive sleep apnea syndrome (OSAS), and thus was evaluated with extreme risk for difficult ventilation and intubation. We planned awake intubation via video-assisted laryngoscopy and fiberoptic bronchoscopy under dexmedetomidine sedation, and the intubation was successfully performed. After adenotonsillectomy, upper airway obstruction due to hemorrhage and oropharyngeal swelling can be life-threatening requiring emergent airway management. Thus for postoperative airway management, due to the possibility of "cannot intubate, cannot ventilate" (CICV) and presumed difficult tracheotomy, we scheduled to perform tracheotomy during adenotonsillectomy, right after anesthetic induction and awake intubation. On postoperative day 1, he started walking with no need of sedative drugs. On day 4, after confirmation of minimal oropharyngeal swelling, tracheal cannulae was removed, and no further complications were observed in his postoperative course. We conclude that careful preoperative evaluation of the airway, retention of spontaneous breathing via awake intubation, and preventive tracheotomy for postoperative airway management are important points in perioperative management of a morbidly obese patient with severe obstructive sleep apnea syndrome.