Dexmedetomidine as an adjuvant to 0.5% ropivacaine in ultrasound-guided axillary brachial plexus block

Abstract

What is known and objective: The aim of this study was to elucidate the effect of dexmedetomidine added to ropivacaine on the onset and duration of sensory and motor block and duration of analgesia of ultrasound-guided axillary brachial plexus block.Methods: Thirty-seven ASA physical status I-II patients with elective forearm and hand surgery under ultrasound-guided axillary brachial plexus block were randomly divided into 2 groups. Patients in ropivacaine-dexmedetomidine group (group RD, n = 19) received 15 mL of 0.5% ropivacaine with 100 μg (1 mL) dexmedetomidine, and patients in ropivacaine group (group R, n = 18) received 15 mL of 0.5% ropivacaine with 1 mL of normal saline. Onset time and duration of sensory and motor block and duration of analgesia were assessed.Results and discussion: Duration of sensory block (U-value = 35, P < .001), duration of motor block (P = .001) and duration of analgesia (P < .001) were extended in group RD compared to group R. Onset time of sensory block in group RD was significantly faster than in group R (U-value = 65.5, P = .001). Onset time of motor block showed no significant difference between the 2 groups (U-value = 116.5, P = .096). Adverse reactions were reported only in group RD (bradycardia in 2 and hypotension in 3 patients). What is new and conclusion:Our study indicated that dexmedetomidine 100 μg as adjuvant on ultrasound-guided axillary plexus block significantly prolonged the duration of sensory block and analgesia, as well as accelerated the time to onset of sensory block. These results should be weighed against the increased risks of motor block prolongation, transient bradycardia and hypotension and allow for attentive optimism, only if prolonged clinical trials provide a definitive answer. K E Y W O R D S axillary brachial plexus block, dexmedetomidine, ropivacaine | WHAT IS KNOWN AND OBJECTIVEThe axillary brachial plexus block is widely used for orthopaedic surgery of the upper extremity as an alternative to general anaesthesia.It is relatively simple to perform and with the advent of ultrasound technology, and there is a marked improvement in success rate of anaesthesia. 1Regional anaesthesia with long-acting local anaesthetics (LAs), such as ropivacaine, is beneficial for effective postoperative pain control, but the duration of sensory block is still not sufficient to avoid | 349 KORAKI et Al.the postoperative use of opioids. Perineural catheters and continuous infusion are an effective alternative to prolong the analgesic effects, 2 but they can present challenges related to patient management, catheter displacement and the potential for increased infection risk. 3 On the other hand, the use of adjuvants, such as adrenaline, clonidine, opioid and steroids, with local anaesthetics for early onset and for prolonging the duration of blocks has been practiced for many years and remains the subject of much interest. 4Dexmedetomidine, a highly selective alpha-2 adrenergic receptor agonist that has an alpha-2 to alpha-1 selectivity ratio 7 times greater than tha...

The effect and safety of dexmedetomidine added to ropivacaine in brachial plexus block

“…The time to onset of sensory block was reported in 12 studies [ 12 – 23 ] and 671 patients were included. Dexmedetomidine combined with ropivacaine reduced the onset time to sensory block significantly (MD, −3.86 minutes, 95% CI −5.45 to −2.27 minutes, I 2 = 85%; P < .00001) (Fig.…”

“…3 ). And adding dexmedetomidine to ropivacaine obviously decreased the time to sensory block onset both in groups with dosage greater [ 12 , 14 , 16 – 21 , 23 ] (MD, −2.97 minutes, 95% CI −4.94 to −1.01 minutes, I 2 = 86%; P = .003) and less [ 13 , 15 , 22 ] (MD, −6.96 minutes, 95% CI −11.85 to −2.06 minutes, I 2 = 86%; P = .005) than 50 μg (Table 2 ).…”

“…Only one trial provided data in seconds, and we converted it into minutes for data consolidation. [ 12 ] In a 3-arm randomized controlled study, we chose one of the experimental groups for data analysis. [ 13 ]…”

“…The 95% confidence intervals (CIs) of all results were calculated or extracted. Due to the different unit of outcomes from Koraki et al, [ 12 ] we finally chose MD as the effect indicator. The adverse events as a second endpoint belong to dichotomous, so the relative risk (RR) was applied.…”

A randomised prospective comparative study of evaluation of dexmedetomidine an adjuvant to ropivacaine for ultrasound guided supraclavicular block

“…(0= no pain, 1=mild annoying pain, 4= nagging uncomfortable troublesome pain, 8= intense dreadful pain, 10=worst possible pain). 13 Rescue analgesia was given, once VAS was more than 4 and was provided in the form of inj tramadol 2 mg/kg intravenously.…”