A randomised trial comparing block characteristics of a mixture versus sequential injections of lignocaine and ropivacaine for supraclavicular brachial plexus nerve block in patients undergoing upper limb surgery.

Background and Aim: There is no consensus on the appropriate use of mixtures of local anaesthetic drugs in various combinations for nerve blocks. We intended to compare short-acting lignocaine and long-acting ropivacaine as a mixture versus undiluted sequential injections on block characteristics of ultrasound-guided (USG) supraclavicular brachial plexus block for upper limb surgeries. Methods: A double-blinded randomised study was conducted on 64 adult patients scheduled for upper limb surgery who received 15 mL each of 2% lignocaine with adrenaline and 0.75% ropivacaine as a 1:1 mixture in the mixed group (Group M) or sequential injections in the sequential group (Group S) by using a USG technique. The primary outcome was the percentage of participants with complete four nerve sensory blocks at 10 minutes post block injection. Secondary outcomes were sensory and motor block characteristics till 30 minutes, total duration of analgesia, sensory and motor block, and complications. Results: Demographic characteristics and time taken for the procedure were similar. The percentage of participants with a complete four-nerve sensory block at 10 minutes was higher in Group S (69%) versus Group M (41%) (P = 0.04). Complete sensory and motor block rates were similar at 30 minutes. The block procedure time, total duration of analgesia, and sensory and motor block were similar in both groups. There were no major complications. Conclusion: Sequential lignocaine-ropivacaine, compared to the mixed injection technique, has a higher initial rate of sensory and motor block onset with a similar total block duration.

Role of carotid corrected flow time and peak velocity variation in predicting fluid responsiveness: a systematic review and meta-analysis.

BACKGROUND: Dynamic parameters used for predicting fluid responsiveness require special equipment and are minimally invasive. Therefore, recent interest in the use of carotid artery ultrasound parameters, such as carotid corrected flow time (FTc) and peak velocity variation (ΔVpeak) has grown. Therefore, we performed this systematic review and meta-analysis to assess the ability of carotid FTc and/or ΔVpeak to accurately predict fluid responsiveness. METHODS: We searched the PubMed and Embase databases for articles evaluating the diagnostic accuracy of carotid FTc or ΔVpeak for predicting fluid responsiveness. Two independent authors performed the search and selected studies published until May 2022. The studies were assessed for the inclusion and exclusion criteria using Rayyan (Rayyan Systems Inc., 2022). RESULTS: Ten studies (n=438) that fulfilled the inclusion criteria were selected. Studies were divided into those assessing carotid FTc and those assessing carotid ΔVpeak. Five studies (six datasets) assessed FTc. The pooled sensitivity and specificity of carotid FTc were 0.76 and 0.88, respectively. The summary receiver operating characteristic (SROC) curve for carotid FTc had an area under the curve (AUC) of 0.9092, with a Q value of 0.8412. Seven studies calculated carotid ΔVpeak. The pooled sensitivity and specificity for ΔVpeak were 0.83 and 0.81, respectively. The SROC curve had an AUC of 0.8941 and a Q value of 0.8250. CONCLUSIONS: Our meta-analysis showed that both carotid FTc and ΔVpeak are useful for predicting fluid responsiveness in anesthesia and critical care settings with good specificity and sensitivity.