Analgesic effects of ultrasound-guided preoperative posterior Quadratus Lumborum block in laparoscopic hepatectomy: A prospective double-blinded randomized controlled trial.

STUDY OBJECTIVE: To determine if single-injection bilateral posterior quadratus lumborum block (QLB) with ropivacaine would improve postoperative analgesia in the first 24 h after laparoscopic hepatectomy, compared with 0.9% saline. DESIGN: Prospective, double blinded, randomized controlled trial. SETTING: A single tertiary care center from November 2021 and January 2023. PATIENTS: A total of 94 patients scheduled to undergo laparoscopic hepatectomy due to hepatocellular carcinoma. INTERVENTIONS: Ninety-four patients were randomized into a QLB group (receiving 20 mL of 0.375% ropivacaine on each side, 150 mg in total) or a control group (receiving 20 mL of 0.9% saline on each side). MEASUREMENTS: The primary outcome was the cumulative opioid consumption during the initial 24-h post-surgery. Secondary outcomes included pain scores and intraoperative and recovery parameters. MAIN RESULTS: The mean cumulative opioid consumption during the initial 24-h post-surgery was 30.8 ± 22.4 mg in the QLB group (n = 46) and 34.0 ± 19.4 mg in the control group (n = 46, mean differences: -3.3 mg, 95% confidence interval, -11.9 to 5.4, p = 0.457). The mean resting pain score at 1 h post-surgery was significantly lower in the QLB group than in the control group (5 [4-6.25] vs. 7 [4.75-8], p = 0.035). No significant intergroup differences were observed in the resting or coughing pain scores at other time points or in other secondary outcomes. CONCLUSIONS: Preoperative bilateral posterior QLB did not reduce cumulative opioid consumption during the first 24 h after laparoscopic hepatectomy.

Effect of high-dose intravenous iron injection on hepatic function in a rat model of cirrhosis.

OBJECTIVE: To investigate the hepatic effects of high-dose intravenous (IV) iron, including those on liver function and the degree of fibrosis, in a rat model of cirrhosis. METHODS: We evenly allocated 25 Sprague-Dawley rats into five groups: normal rats (control group), cirrhotic rats receiving IV normal saline (liver cirrhosis [LC] group), and cirrhotic rats receiving 20, 40, or 80 mg/kg IV ferric carboxymaltose (LC-iron20, LC-iron40, and LC-iron80 group, respectively). Biochemical parameters were compared at 0, 7, 14, 21, and 28 days. The degrees of hepatic fibrosis and iron deposition were evaluated. Inflammatory and oxidative stress markers were also compared. RESULTS: There were no significant differences in the 28-day serum alanine aminotransferase levels among the LC-iron20, LC-iron40, and LC-iron80 groups (69 ± 7, 1003 ± 127, 1064 ± 309, 919 ± 346, and 820 ± 195 IU/L in the control, LC, LC-iron20, LC-iron40, and LC-iron80 groups, respectively). Hepatic iron accumulation increased in a dose-dependent manner, but the degree of hepatic fibrosis was comparable among the groups. The inflammatory and oxidative stress marker levels did not differ significantly according to the IV iron dose. CONCLUSIONS: Administration of IV iron at various high doses appears safe in our rat model of cirrhosis.

Analgesic efficacy of erector spinae plane block in patients undergoing major gynecologic surgery: A randomized controlled study.

STUDY OBJECTIVE: To investigate the analgesic efficacy of erector spinae plane block (ESPB) in major gynecologic surgery, expressed as cumulative opioid consumption 24 h after surgery. DESIGN: A single-center, patient-assessor blinded, randomized controlled study. SETTING: Samsung medical center (tertiary university hospital), between February 2022 to January 2023. PATIENTS: Eighty-eight females undergoing major surgery with long midline incision for gynecologic malignancy. INTERVENTIONS: Patients were randomly assigned to receive standard systemic analgesia (Control group) or ESPB (ESPB group). ESPB was performed bilaterally at the level of the 9th thoracic vertebra with a mixture of 20 mL of 0.5% ropivacaine and 100 µg of epinephrine. MEASUREMENTS: The primary outcome was cumulative opioid consumption at 24 h postoperatively. Secondary outcomes included opioid consumption and pain severity during the 72 h after surgery. The variables regarding postoperative recovery and patient-centered outcomes were compared. MAIN RESULTS: The mean cumulative opioid consumption 24 h after surgery was 35.8 mg in the ESPB group, which was not significantly different from 41.4 mg in the control group (mean difference, 5.5 mg; 95% CI -1.7 to 12.8 mg; P = 0.128). However, patient satisfaction regarding analgesia was significantly higher in the ESPB group compared with the control group at 24 h postoperative (median difference, -1; 95% CI -3 to 0; P = 0.038). There were no significant differences in the variables associated with postoperative recovery. CONCLUSION: ESPB did not reduce opioid consumption during the 24 h postoperative but attenuated pain intensity during the early period after surgery.

The Efficacy of Scalp Nerve Block in Postoperative Pain Management after Microvascular Decompression: A Randomized Clinical Trial.

The scalp nerve block, created by injecting local anesthetics around the scalp nerves, is reported to effectively reduce pain after surgery. In this study, we evaluated the efficacy of scalp nerve block in patients with hemifacial spasm (HFS) undergoing microvascular decompression (MVD). Seventy-four patients who underwent MVD for HFS were enrolled. The block group received scalp nerve block with 0.5% ropivacaine before surgery. The primary outcome was cumulative dose of rescue analgesics 24 h postoperatively. The secondary outcomes were included pain scores, postoperative antiemetic consumption, and Quality of Recovery-15 scale. The cumulative dose of rescue analgesics at 24 h postoperatively was not significantly different between the two groups (4.80 ± 3.64 mg vs. 5.92 ± 3.95 mg, p = 0.633). However, the pain score was significantly reduced in the block group at 6, 12, and 24 h postoperatively. Postoperative antiemetic consumption was lower in the block group than the control group at 12 h. There were no significant differences between the two groups for other secondary outcomes. In MVD for HFS, a preoperative scalp nerve block might reduce postoperative pain in the early postoperative period, but a larger study using a multimodal approach is needed to confirm the efficacy of a scalp block.

Comparison of postoperative analgesic effects of erector spinae plane block and quadratus lumborum block in laparoscopic liver resection: study protocol for a randomized controlled trial.

BACKGROUND: Compared with open surgery, laparoscopic liver resection is a minimally invasive surgical technique. However, a number of patients experience moderate-to-severe postoperative pain after laparoscopic liver resection. This study aims to compare the postoperative analgesic effects of erector spinae plane block (ESPB) and quadratus lumborum block (QLB) in patients undergoing laparoscopic liver resection. METHODS: One hundred and fourteen patients undergoing laparoscopic liver resection will be randomly allocated to three groups (control, ESPB, or QLB) in a 1:1:1 ratio. In the control group, participants will receive systemic analgesia consisting of regular NSAIDs and fentanyl-based patient-controlled analgesia (PCA) according to the institutional postoperative analgesia protocol. In the two experimental groups (ESPB or QLB group), the participants will receive preoperative bilateral ESPB or bilateral QLB in addition to systemic analgesia according to the institutional protocol. ESPB will be performed at the 8th thoracic vertebra level with ultrasound guidance before surgery. QLB will be performed in the supine position on the posterior plane of the quadratus lumborum with ultrasound guidance before surgery. The primary outcome is cumulative opioid consumption 24 h after surgery. Secondary outcomes are cumulative opioid consumption, pain severity, opioid-related adverse events, and block-related adverse events at predetermined time points (24, 48, and 72 h after surgery). Differences in plasma ropivacaine concentrations in the ESPB and QLB groups would be investigated, and the quality of postoperative recovery among the groups will be compared. DISCUSSION: This study will reveal the usefulness of ESPB and QLB in terms of postoperative analgesic efficacy and safety in patients undergoing laparoscopic liver resection. Additionally, the study results will provide information on the analgesic superiority of ESPB versus QLB in the same population. TRIAL REGISTRATION: Prospectively registered with the Clinical Research Information Service on August 3, 2022; KCT0007599.

Effect of chewing gum on anxiety in women undergoing elective cesarean section: a randomized controlled study.

BACKGROUND: Preoperative anxiety is a common problem in pregnant women undergoing elective cesarean section. We aimed to determine the anxiolytic effects of chewing gum in pregnant women undergoing elective cesarean section under regional anesthesia. METHODS: This was a single-center, prospective, randomized controlled trial. Sixty-six women were randomly assigned to either the control group (n=33) or gum group (n=33) in a 1:1 ratio. In the gum group, the participants chewed xylitol gum for at least 10 min/h, regardless of fasting. Gum chewing was started at 5 pm a day before surgery and continued till the participant entered the operation room. In the control group, participants were requested to follow fasting guidelines without further instruction. The primary outcome was preoperative anxiety measured using the Amsterdam Preoperative Anxiety and Information Scale (APAIS) immediately before surgery. RESULTS: The APAIS score immediately before surgery showed no significant difference between the control and the gum group (19.2±5.8 vs. 19.1±4.1, P>0.99). There were no statistically significant differences in the eight items related to anxiety: unfitness, concentration difficulty, hunger, thirst, dry mouth, fatigue, headache, and nausea. However, the pain score during the procedure of combined spinal epidural anesthesia was significantly lower in the chewing gum group [4 (IQR, 3-5.5)] than in the control group [5 (IQR, 3-7), P=0.045]. CONCLUSIONS: Preoperative gum chewing did not reduce anxiety levels measured immediately before entering the operating room in the participants undergoing elective cesarean section. TRIAL REGISTRATION: Clinical Trial Registry of Korea: https://cris.nih.go.kr/cris/index.jsp and identifier: KCT0006602; date of registration: September 27, 2021; principal investigator's name: RyungA Kang.

Comparison of two doses of intrathecal morphine in laparoscopic donor hepatectomy: A randomized double-blinded non-inferiority trial.

BACKGROUND: Intrathecal morphine (ITM) injection is an effective postoperative analgesic strategy in open or laparoscopic donor hepatectomy; however, the optimal dose has not been determined. In this trial, we compared the post-operative analgesic effects of two doses (300 vs. 400 µg) of ITM injections. METHODS: In this prospective randomized non-inferiority trial, 56 donors were divided into either the 300 µg or 400 µg ITM group (n = 28, each). The primary outcome was the resting pain score at 24 h postoperatively. Pain scores, cumulative opioid consumption, and side effects (postoperative nausea and vomiting [PONV]) were compared up to 48 h postoperatively. RESULTS: Fifty-five donors participated in the entire study. The mean resting pain scores at 24 h after surgery were 1.7 ± 1.6 and 1.7 ± 1.1 in the ITM 300 and ITM 400 groups, respectively (mean difference, 0 [95% CI, -.8 to .7], p = .978). The upper limit of the 95% CI was lower than the prespecified non-inferiority margin (δ = 1), indicating that non-inferiority had been established. The incidence of PONV was lower in the ITM 300 group than in the ITM 400 group at 18 (p = .035) and 24 h postoperatively (p = .015). There were no significant differences in the resting and coughing pain scores and cumulative opioid consumption at any time point. CONCLUSION: For laparoscopic donor hepatectomy, preoperative ITM 300 µg exhibited non-inferior postoperative analgesic effects compared to ITM 400 µg, with a lower incidence of PONV.

Recent updates on interscalene brachial plexus block for shoulder surgery.

Interscalene brachial plexus block (ISBPB) provides optimal analgesia for shoulder surgery. However, several limitations still exist, including the short duration of analgesia, rebound pain, a high incidence of unilateral diaphragmatic paresis, and potential risk of nerve damage, prompting the search for alternative techniques. Many alternatives to ISBPB have been studied to alleviate these concerns, and clinicians should choose an appropriate option based on the patient's condition. In this mini-review, we aimed to present recent updates on ISBPB while discussing our clinical experiences in shoulder surgery.

Comparison of Analgesic Efficacy of Erector Spinae Plane Block and Posterior Quadratus Lumborum Block in Laparoscopic Liver Resection: A Randomized Controlled Trial.

PURPOSE: Ultrasound-guided fascial plane blocks, including the erector spinae plane (ESP) and quadratus lumborum (QL) blocks, provide effective postoperative abdominal analgesia. However, there is limited evidence on the analgesic efficacy of ESP and QL blocks after liver surgery. Therefore, we aimed to compare the cumulative opioid consumption between the ESP and QL blocks in patients with hepatocellular carcinoma undergoing laparoscopic liver resection. PATIENTS AND METHODS: Eighty-eight patients scheduled to undergo laparoscopic liver resection were randomized to receive bilateral single injection of ESP block at T8 (ESP group) or bilateral single injection of posterior QL block (QL group; 20 mL of 0.375% ropivacaine for each side, ie, total 150 mg of ropivacaine), in addition to intravenous (IV) fentanyl patient-controlled analgesia and multimodal analgesia. The primary outcome was cumulative opioid consumption over the first 24 h, expressed as IV morphine equivalents. Secondary outcomes included serial plasma ropivacaine concentrations, pain scores, time to first flatus, and Quality of Recovery-15 scores. RESULTS: Eighty-five patients were analyzed (ESP group, n = 42; QL group, n = 43). Cumulative 24-h opioid consumption was similar between the ESP and QL groups (41.4 ± 22.6 mg vs 44.2 ± 20.0 mg, mean difference (QL-ESP), 2.8 mg, 95% confidence interval, -6.4 to 12 mg, p > 0.99). There were no significant differences in resting pain scores at 24, 48 and 72 h postoperatively or recovery outcomes. The peak plasma ropivacaine concentration 30 min after injection was significantly higher in the ESP group (1.5 ± 0.3 µg/mL) than in the QL group (1.3 ± 0.5 µg/mL, p = 0.035); however, both were lower than the arterial threshold value of systemic toxicity (4.3 µg/mL). CONCLUSION: ESP and QL blocks provided similar postoperative analgesia in patients undergoing laparoscopic liver resection.

Bilateral continuous erector spinae plane block using a programmed intermittent bolus regimen versus intrathecal morphine for postoperative analgesia in living donor laparoscopic hepatectomy: A randomized controlled trial.

STUDY OBJECTIVE: To determine if continuous bilateral erector spinae plane (ESP) blocks would improve the postoperative analgesia in the first 48 h after laparoscopic donor hepatectomy, compared to intrathecal morphine (ITM). DESIGN: Prospective, randomized controlled trial. SETTING: A single tertiary care center from October 2019 and September 2020. PATIENTS: A total of 60 donors scheduled to undergo elective laparoscopic right hepatectomy. INTERVENTIONS: Sixty donors were randomized to receive either bilateral continuous T8 ESP blocks with a programmed intermittent bolus regimen of 10 mL 0.2% ropivacaine every 3 h for 48 h (n = 30) or 400 µg ITM (n = 30), in addition to IV fentanyl PCA and multimodal analgesia. MEASUREMENTS: The primary outcome was cumulative opioid consumption over the first 48 h, expressed as IV morphine equivalents. Secondary outcomes included pain scores, Quality of Recovery-15 scores, ambulation within 24 h, time to first flatus, and opioid-related adverse drug events over 72 h. MAIN RESULTS: Fifty-nine donors were analyzed. Cumulative 48-h opioid consumption was similar between the ITM and ESP groups (29.8 ± 18.2 vs. 35.1 ± 21.9 mg, mean difference (ESP-ITM) (95% CI), 5.3 (-11.5 to 22) mg; p > 0.99). Resting pain scores at 48 and 72 h postoperatively were significantly lower in the ESP group (0 [0-2] vs. 3 [1.5-3], and 0 [0-2] vs. 3 [1-3] respectively, both p<0.001) (Goldaracena and Barbas, 2019; Ko et al., 2009; Choi et al., 2007 [1-3]) respectively, both p < 0.001). The ESP group had significantly lower incidences of postoperative nausea, vomiting, and pruritus at all timepoints. There were no differences in recovery outcomes. CONCLUSIONS: Continuous ESP blocks did not reduce cumulative 48-h opioid consumption compared to 400 µg ITM after laparoscopic donor hepatectomy, but it was associated with a significantly reduced risk of postoperative nausea, vomiting and pruritus. CLINICAL TRIAL NUMBER AND REGISTRY URL: Clinical Trial Registry of Korea; https://cris.nih.go.kr/cris/index.jsp and identifier: KCT0004313; date of registration: October 15, 2019; principal investigator's name: Justin Sangwook Ko.

Intraoperative dexmedetomidine attenuates norepinephrine levels in patients undergoing transsphenoidal surgery: a randomized, placebo-controlled trial.

BACKGROUND: Dexmedetomidine has sympatholytic effects. We investigated whether dexmedetomidine could attenuate stress responses in patients undergoing endoscopic transnasal transseptal transsphenoidal surgery. METHODS: Forty-six patients were randomized to receive a continuous infusion of 0.9% saline (n = 23) or dexmedetomidine (n = 23). Immediately after general anesthesia induction, the dexmedetomidine group received a loading dose of 1 mcg/kg dexmedetomidine over 10 min, followed by a maintenance dose of 0.2-0.7 mcg/kg/h and the control group received 0.9% saline at the same volume until 30 min before the end of surgery. Serum levels of epinephrine, norepinephrine, and glucose were assessed before surgery (T1) and the end of drug infusion (T2). The primary outcome was the change in norepinephrine levels between the two time points. RESULTS: Changes (T2-T1 values) in perioperative serum norepinephrine levels were significantly greater in the dexmedetomidine group than in the control group (median difference, 56.9 pg/dL; 95% confidence interval, 20.7 to 83.8 pg/dL; P = 0.002). However, epinephrine level changes did not show significant intergroup differences (P = 0.208). Significantly fewer patients in the dexmedetomidine group than in the control group required rescue analgesics at the recovery area (4.3% vs. 30.4%, P = 0.047). CONCLUSIONS: Intraoperative dexmedetomidine administration reduced norepinephrine release and rescue analgesic requirement. Dexmedetomidine might be used as an anesthetic adjuvant in patients undergoing transnasal transseptal transsphenoidal surgery. TRIAL REGISTRATION: Clinical Trial Registry of Korea, identifier: KCT0003366; registration date: 21/11/2018; presenting author: Ji Seon Jeong.

Neutral Position Facilitates Nasotracheal Intubation with a GlideScope Video Laryngoscope: A Randomized Controlled Trial.

The optimal head position for GlideScope facilitated nasotracheal intubation has not yet been determined. We compared the neutral and sniffing positions to establish the degree of intubation difficulty. A total of 88 ASA I-II patients requiring nasotracheal intubation for elective dental surgery with normal airways were divided into two groups according to head position, neutral position (group N), and sniffing position (group S). The primary outcome was the degree of intubation difficulty according to the Intubation Difficulty Scale (IDS): Easy (IDS = 0), mildly difficult (IDS = 1 to 4), and moderately to severely difficult (IDS ≥ 5). Eighty-seven patients completed the study and their data were analyzed. The degree of intubation difficulty was significantly different between the two groups (p = 0.004). The frequency of difficult intubation (IDS > 0) was 12 (27.9%) in group N and 28 (63.6%) in group S (difference in proportion, 35.7%; 95% confidence interval [CI], 14.8 to 52.6%; p = 0.001). The neutral position facilitates nasotracheal intubation with GlideScope by aligning the nasotracheal tube and the glottis inlet more accurately than the sniffing position.

Effect of Intraoperative Sedation with Dexmedetomidine Versus Propofol on Acute Postoperative Pain Following Major Foot Surgery under Popliteal Sciatic Nerve Block: A Randomized Controlled Trial.

Intravenous (IV) dexmedetomidine is reported to prolong analgesia following peripheral nerve blocks. Popliteal sciatic nerve block provides effective postoperative analgesia, but some patients still experience severe pain during the early postoperative period. We aimed to evaluate the postoperative analgesic effects of IV dexmedetomidine versus propofol in patients undergoing foot surgeries under popliteal sciatic nerve block. Forty patients were enrolled and randomly assigned to receive either IV propofol (n = 20) or IV dexmedetomidine (n = 20) for intraoperative sedation. All the patients received continuous popliteal sciatic nerve block. The corresponding drug infusion rate was adjusted to achieve a modified observer's assessment of alertness/sedation score of 3 or 4. The primary outcome was postoperative cumulative opioid consumption during the first 24 h after surgery. Thirty-nine patients were analyzed. The median (interquartile ranges) postoperative cumulative opioid consumption during the first 24 h after surgery was significantly lower in the dexmedetomidine group (15 (7.5-16.9) mg) than in the propofol group (17.5 (15-25) mg) (p = 0.019). The time to first rescue analgesic request was significantly greater in the dexmedetomidine group than in the propofol group (11.8 ± 2.2 h vs. 10.0 ± 2.7 h, p = 0.030) without the prolonged motor blockade (p = 0.321). Intraoperative sedation with dexmedetomidine reduced postoperative opioid consumption and prolonged analgesic duration after a popliteal sciatic nerve block.

Postoperative hyperglycemia may negatively impact cytomegalovirus infection in seropositive liver transplant recipients: a retrospective cohort study.

The aim of the study was to evaluate the association between postoperative hyperglycemia and CMV infection. We analyzed 741 CMV seropositive recipients, of livers from seropositive living donors, who underwent preemptive CMV treatment without CMV prophylaxis. The primary outcome was early CMV infection within 1 month after surgery. Hyperglycemia was defined when mean postoperative blood glucose concentration was >180 mg/dl based on previous research and guidelines. Survival analysis was performed using the Fine and Gray model by accounting for the competing risk of CMV infection-unrelated death. Of the 741 recipients (hyperglycemic group, n = 287; nonhyperglycemic group, n = 454), 372 (50.2%) recipients developed cytomegalovirus (CMV) infection within 1 month after surgery. CMV infection risk was significantly higher in hyperglycemic group than in nonhyperglycemic group in univariable analysis [hazard ratio (HR) 1.34, 95% confidence interval (CI), 1.08-1.66; P = 0.007] and in multivariable analysis (HR 1.25, 95% CI 1.0-1.54; P = 0.038). CMV infection risk was also significantly associated with recipient age, graft ischemia time, model for end-stage liver disease score, and preoperative neutrophil-to-lymphocyte ratio (P < 0.05). In conclusion, preventing postoperative hyperglycemia appears to be an important factor decreasing the risk of CMV infection in seropositive liver transplant recipients undergoing preemptive CMV treatment.

Bilateral single-injection erector spinae plane block versus intrathecal morphine for postoperative analgesia in living donor laparoscopic hepatectomy: a randomized non-inferiority trial.

BACKGROUND: Intrathecal morphine (ITM) provides effective postoperative analgesia in living donor hepatectomy but has significant adverse effects. Studies support the efficacy of erector spinae plane (ESP) blocks in laparoscopic abdominal surgery; we therefore hypothesized that they would provide non-inferior postoperative analgesia compared with ITM and reduce postoperative nausea/vomiting and pruritus. We conducted a randomized, controlled, non-inferiority trial to compare the analgesic efficacy of ITM and bilateral single-injection ESP blocks in laparoscopic donor hepatectomy. METHODS: Fifty-four donors were randomized to receive bilateral ESP blocks with 20 mL 0.5% ropivacaine (n=27) or 400 µg ITM (n=27). Primary outcome was resting pain score 24 hours postoperatively measured on an 11-point numeric rating scale. The prespecified non-inferiority limit was 1. Incidences of postoperative nausea/vomiting and pruritus were assessed. RESULTS: The mean treatment difference (ESP-ITM) in the primary outcome was 1.2 (95% CI 0.7 to 1.8). The 95% CI upper limit exceeded the non-inferiority limit. Opioid consumption and all other pain measurements were similar between groups up to 72 hours postoperatively. The ESP group had significantly lower incidences of postoperative vomiting (p=0.002) and pruritus (p<0.001). CONCLUSIONS: Bilateral single-injection ESP blocks resulted in higher resting pain scores 24 hours postoperatively compared with ITM and thus did not meet the study definition of non-inferiority. However, the pain intensity with ESP blocks was mild (mean pain scores <3/10) and associated with reduced incidence of postoperative vomiting and pruritus. It warrants further investigation as an analgesic option after laparoscopic living donor hepatectomy. TRIAL REGISTRATION NUMBER: KCT0003191.

Superior Trunk Block Provides Noninferior Analgesia Compared with Interscalene Brachial Plexus Block in Arthroscopic Shoulder Surgery.

BACKGROUND: Interscalene brachial plexus block of the C5-C6 roots provides highly effective postoperative analgesia after shoulder surgery but usually results in hemidiaphragmatic paresis. Injection around the superior trunk of the brachial plexus is an alternative technique that may reduce this risk. The authors hypothesized that the superior trunk block would provide noninferior postoperative analgesia compared with the interscalene block and reduce hemidiaphragmatic paresis. METHODS: Eighty patients undergoing arthroscopic shoulder surgery were randomized to receive a preoperative injection of 15 ml of 0.5% ropivacaine and 5 µg · ml epinephrine around either (1) the C5-C6 nerve roots (interscalene block group) or (2) the superior trunk (superior trunk block group). The primary outcome was pain intensity 24 h after surgery measured on an 11-point numerical rating score; the prespecified noninferiority limit was 1. Diaphragmatic function was assessed using both ultrasonographic measurement of excursion and incentive spirometry by a blinded investigator before and 30 min after block completion. RESULTS: Seventy-eight patients completed the study. The pain score 24 h postoperatively (means ± SDs) was 1.4 ± 1.0 versus 1.2 ± 1.0 in the superior trunk block (n = 38) and interscalene block (n = 40) groups, respectively. The mean difference in pain scores was 0.1 (95% CI, -0.3 to 0.6), and the upper limit of the 95% CI was lower than the prespecified noninferiority limit. Analgesic requirements and all other pain measurements were similar between groups. Hemidiaphragmatic paresis was observed in 97.5% of the interscalene block group versus 76.3% of the superior trunk block group (P = 0.006); paresis was complete in 72.5% versus 5.3% of the patients, respectively. The decrease in spirometry values from baseline was significantly greater in the interscalene block group. CONCLUSIONS: The superior trunk block provided noninferior analgesia compared with interscalene brachial plexus block for up to 24 h after arthroscopic shoulder surgery and resulted in significantly less hemidiaphragmatic paresis.

Incidence of tolerance in children undergoing repeated administration of propofol for proton radiation therapy: a retrospective study.

BACKGROUND: Propofol is an excellent hypnotic drug for use in repeated radiation procedures in young children. To date, tolerance to propofol generally does not develop in pediatric patients undergoing radiation therapy. However, several studies have suggested that there may be potential for development of tolerance to propofol. The aim of this study was to evaluate the development of a tolerance to propofol used for repeated deep sedation in children undergoing proton radiation therapy (PRT). METHODS: All children undergoing PRT at our institution between December 2015 and January 2018 were eligible for inclusion in this study. Sedation was induced by a bolus dose of propofol (2.0 mg.kg- 1) followed by a continuous infusion of 250 µg.kg- 1.min- 1 via an infusion pump to achieve deep sedation. Sedation was maintained with the propofol infusion of 200 µg.kg- 1.min- 1, which was adjusted in 25 µg.kg- 1.min- 1 increments up or down as necessary to ensure deep sedation. The primary outcome was mean doses of propofol over time. RESULTS: Fifty-eight children were analyzed. The mean (SD) age was 4.5 (2.1) years. The mean (SD) number of treatment sessions was 19 (7). Fifteen patients (26%) developed tolerance to propofol. However, there were no significant differences between the children who developed tolerance and the children who did not develop tolerance in mean propofol dose and awakening time over time (p = 0.887 and P = 0.652, respectively). Age, the number of PRT, and attending anesthesiologists was not significantly associated with the incidence of tolerance to propofol. CONCLUSION: Repeated prolonged deep sedation for PRT elicited multiple times over several weeks in young children using propofol did not develop tolerance in 74% of patients. Although the incidence of 26% tolerance to propofol may still be present, the increase in propofol dose was minimal. Therefore, the use of repeated propofol for children was safe.

Effective Dose of Intravenous Dexmedetomidine to Prolong the Analgesic Duration of Interscalene Brachial Plexus Block: A Single-Center, Prospective, Double-Blind, Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: Intravenous (IV) dexmedetomidine (DEX) is reported to prolong the analgesic duration after single-shot interscalene brachial plexus block (ISBPB). However, the effective analgesic dose of IV DEX remains undetermined. Therefore, we aimed to elucidate the clinically relevant dose of IV DEX to prolong the analgesic duration of ISBPB. METHODS: Seventy-two patients scheduled for arthroscopic shoulder surgery received ISBPB with 15 mL of 0.5% ropivacaine with 1:200,000 epinephrine and were randomly assigned to 1 of 4 groups (n = 18, each): (1) IV normal saline (control), (2) IV DEX 0.5 µg/kg (DEX 0.5), (3) IV DEX 1.0 µg/kg (DEX 1.0), and (4) IV DEX 2.0 µg/kg (DEX 2.0). The primary outcome was time to the first pain at surgical site. RESULTS: The median (interquartile range) duration of analgesia was significantly prolonged for the DEX 2.0 (874 minutes [727-1153 minutes]) compared with 656 minutes (590-751 minutes), 703 minutes (644-761 minutes), and 696 minutes (615-814 minutes) for the control, DEX 0.5 and DEX 1.0 groups, respectively (P = 0.001, P = 0.008, and P = 0.003, respectively). Postoperative cumulative IV morphine equivalent consumption at 24 hours was significantly lower in the DEX 2.0 compared with the control, DEX 0.5 and DEX 1.0 groups (P < 0.001, P < 0.001, and P = 0.007, respectively). There were no significant differences in the incidence of intraoperative hypotension and the number of patients who required ephedrine after the pairwise group analysis. Also, there were no significant differences on the durations of motor blockade and sedation and the incidence of bradycardia. CONCLUSIONS: Intravenous DEX at a dose of 2.0 µg/kg significantly increased the duration of ISBPB analgesia without prolonging motor blockade and reduced the cumulative opioid consumption at the first 24 hours in patients undergoing arthroscopic shoulder surgery. CLINICAL TRIAL REGISTRATION: This study was registered at the Clinical Trial Registry of Korea, identifier KCT0002119.

The effect of passive leg elevation and/or trendelenburg position on the cross-sectional area of the internal jugular vein in infants and young children undergoing surgery for congenital heart disease.

BACKGROUND: In this study we evaluated the effect of passive leg elevation (LE) and Trendelenburg (T) position on the cross-sectional area (CSA) of the internal jugular vein (IJV) in infants and young children undergoing surgery for congenital heart disease. A secondary aim was to compare the CSA of the IJV between subjects with right-to-left (RL) shunt and left-to-right (LR) shunt. METHODS: Ninety infants and small children from 10 days to 31 months old weighing from 1.5 to 9.7 kg were assigned to group RL (n = 48) or LR (n = 42). In both groups, the CSA, transverse, and vertical diameters of the IJV on both sides of the neck were measured using a 2-dimensional ultrasound transducer in the following positions: supine position, 15° of T position, supine position with 50° of LE, and 15° of Trendelenburg position with 50° of LE (TLE). A more than 25% increase in mean CSA of the IJV was considered clinically significant. RESULTS: In group LR, T, LE, and TLE significantly increased CSA of both right (at least 12.3%, 10.3%, and 18.3%, respectively, "at least" refers to the lower 95% confidence limits) and left (at least 15.8%, 15.0%, and 18.9%, respectively) IJVs, whereas only TLE increased the CSA of both IJVs significantly in group RL (at least 8.2% and 7.7% in the right and left, respectively). The increase in the CSA of the right IJV related to T and TLE was larger in group LR than in group RL (at least 12.3% vs 1.2% for T and at least 18.3% vs 8.2% for TLE, respectively). A clinically significant increase in CSA was achieved in both right and left IJVs with TLE in group LR (mean 28.6% and 26.3%, respectively). The CSA of the right IJV was larger than that of the left IJV in most (at least 69.2%) patients. CONCLUSIONS: Passive LE was as effective as T position to increase the CSA of the IJV, but there was no clinically significant increase in the CSA with any single maneuver. Only T position with passive LE achieved a clinically significant increase in the CSA of both IJVs in infants and young children with LR shunt, but not in the same age group with RL shunt.