RESUMO
CONTEXT: The supraclavicular brachial plexus block is a very safe, useful and effective method for upper limb surgeries. Among local anesthetics, ropivacaine has special applications in neuraxial and peripheral nerve blocks due to its low cardiotoxicity and less toxicity to central nervous systems compared to bupivacaine and lignocaine. Dexmedetomidine is a newer and potent alpha-2 receptor agonist which has 10 times higher selectivity for alpha-2 receptors as compared to clonidine, So far, very few studies have been undertaken to compare the efficacy of clonidine and dexmedetomidine to provide and prolong postoperative analgesia, especially with the use of ultrasound for nerve localization. AIMS: To compare the efficacy of postoperative analgesia between clonidine and dexmedetomidine as adjuvants with 0.5% ropivacaine by ultrasound-guided supraclavicular brachial plexus block for upper limb surgeries. SETTINGS AND DESIGN: Prospective, randomised, double-blind interventional study. SUBJECTS AND METHODS: Eighty patients of ASA grade I or II undergoing elective upper limb surgery were randomly divided into two groups:- Group RC (n = 40) received 35 ml of 0.5% ropivacine with 1 µg.kg-1 of clonidine. Group RD (n = 40) received 35 ml of 0.5% ropivacaine with 1 µg.kg-1 of dexmedetomidine. STATISTICAL ANALYSIS USED: The statistical software SPSS version 20 has been used for the analysis. By using Pearson's Chi-Square test for Independence of Attributes/Fisher's Exact. Continuous variables were expressed as Mean, Median, and Standard Deviation and compared across the groups using unpaired t-test. RESULTS: In our comparative study, dexmedetomidine 1 µg.kg-1 with 35 ml of 0.5% ropivacaine provided significantly longer duration of postoperative analgesia and earlier sensory block as compared to clonidine 1 µg.kg-1 with same dose of ropivacaine in ultrasound-guided supraclavicular brachial plexus block. CONCLUSIONS: The ropivacaine-dexmedetomidine group in our study provided earlier sensory block and more prolonged postoperative analgesia as compared to ropivacaine-clonidine group. Thus ropivacaine-dexmedetomidine combination may be effectively used in all painful upper limb surgeries specially orthopaedic procedures.
RESUMO
An environmentally benign Au(III)-catalyzed regio- and stereoselective domino synthesis of oxazolo fused pyridoindoles 7a-v and benzofurooxazolo pyridines 8a-n by the reaction of o-alkynylaldehydes 4a-t and 5a-k with (S)-phenylglycinol 6a and (R)-phenylglycinol 6b under mild reaction conditions using water as reaction medium is reported. The reaction proceeded via selective C-N bond formation on the more electrophilic alkynyl carbon through 6-endo-dig cyclization. The reaction tolerates a wide variety of functional groups. The developed chemistry has been successfully extended for the synthesis of a diverse class of γ-carbolines and benzofuro[3,2-c]pyridines using corresponding ester hydrochlorides of serine, threonine, and cystine as a nitrogen source.
RESUMO
An operationally simple silver-catalyzed tandem strategy for the synthesis of benzothienopyridines 7a-t and benzofuropyridines 8a-p by the reaction of o-alkynyl aldehyde 4a-t and 5a-p with tert-butylamine 6 under mild reaction conditions is described. The present methodology provides a facile conversion of easily accessible o-alkynyl aldehydes into medicinally useful heterocycles in good to excellent yields under mild and environmentally friendly reaction conditions with excellent regioselectivity. The developed chemistry has been successfully extended for the selective synthesis of C-4 deuterated benzothienopyridines 7u-v and benzofuropyridines 8q-r. The role of the ethanolic proton in the reaction was validated by deuterium-labeling experiments.
