Effect of dexmedetomidine on characteristics of ultrasound-guided supraclavicular brachial plexus block with levobupivacaine-A prospective double-blind randomized controlled trial.

BACKGROUND AND AIMS: Levobupivacaine, a less cardiotoxic s-isomer of bupivacaine, is proved to be similar to bupivacaine, hence, proposed as a safer alternative for nerve blocks. We aimed to evaluate the effect of perineural and intravenous dexmedetomidine on characteristics of ultrasound-guided supraclavicular brachial plexus block (BPB) performed with levobupivacaine. The aim of this study is to evaluate the effect of perineural and intravenous dexmedetomidine on characteristics of ultrasound-guided supraclavicular BPB performed with levobupivacaine. MATERIAL AND METHODS: A prospective, randomized double-blind control trial done on 120 patients undergoing elective upper limb surgical procedures under supraclavicular BPB. The enrolled patients were allocated to one of the three groups: Group L - 0.5% levobupivacaine +0.9% normal saline (NS) IV infusion; Group LDI - 0.5% levobupivacaine + dexmedetomidine (1 mcg/kg) in NS IV infusion; and Group LDP - 0.5% levobupivacaine +1 mcg/kg of dexmedetomidine perineural + NS IV infusion. The onset and duration of sensory and motor blockade were recorded in minutes. One-way ANOVA was used to observe any differences between the groups, and post hoc comparisons were conducted after Bonferroni correction for multiple comparisons. RESULTS: The onset of sensory and motor blockade in Group LDP was significantly shorter than Group L and Group LDI. The duration of sensory blockade in Group LDP was significantly longer than Group LDI and Group L. The duration of motor blockade in Group LDP was prolonged compared to Group LDI and Group L. CONCLUSIONS: When dexmedetomidine is added as adjunct to levobupivacaine in supraclavicular BPB, onset of sensory and motor blockade is faster in perineural group, whereas duration of sensory and motor blockade and duration of analgesia are more prolonged when used perineurally than intravenously.

Ratio of height-to-thyromental distance and ratio of height-to-sternomental distance as predictors of laryngoscopic grade in children.

BACKGROUND AND AIMS: Failure to secure the airway is an important cause of morbidity and mortality in children. Children are often uncooperative for routine examination and pose problems for obtaining external measurements. We aimed to evaluate ratio of height-to-thyromental distance (RHTMD) and ratio of height-to-sternomental distance (RHSMD) as predictors of laryngoscopic grade in children aged 1-12 years. MATERIAL AND METHODS: This study was an observational study conducted in children aged between 1 and 12 years scheduled for elective surgery under general anesthesia. Children unable to stand, having limited mouth opening/neck mobility, cleft palate or with midline neck masses were excluded. Weight, height, and thyromental and sternomental distances were measured preoperatively. Following induction of anesthesia and full-muscle relaxation, laryngoscopy was performed and Cormack-Lehane view with Cook's modification was noted. Receiver operating characteristic (ROC) curve analysis using RHTMD and RHSMD was performed for predicting poor laryngoscopic view. RESULTS: A total of 138 children with mean age of 6.6 ± 3.4, RHTMD of 17.7 ± 2.1, and RHSMD of 10.0 ± 1.0 were included. No Grade 3 or 4 laryngoscopic views were obtained. ROC curve analysis was done for predicting 2b view (restricted), incidence of which was 10.1%. RHTMD was a better predictor of 2b laryngoscopic view with an area under curve (AUC) of 0.792 compared to RHSMD (AUC = 0.463). CONCLUSIONS: In children aged 1-12 years, RHTMD is a better predictor of restricted view compared to RHSMD.