Objective To evaluate the effect of dexmedetomidine on postoperative outcomes in ped?iatric patients undergoing open reduction and internal fixation following upper limb fracture performed under sevoflurane anesthesia combined with brachial plexus block. Methods Sixty American Society of Anesthe?siologists physical status Ⅰ pediatric patients of both sexes, aged 6-12 yr, with body mass index <24 kg∕m2, scheduled for elective open reduction and internal fixation following upper limb fracture, were ran?domly divided into ropivacaine group(group R)and dexmedetomidine mixed with ropivacaine group (group DR), with 30 cases in each group. Interscalene brachial plexus block was performed under ultra?sound guidance after sevoflurane anesthesia, 0.25% ropivacaine plus 1 μg∕kg dexmedetomidine(0.3 ml∕kg)was given in group DR, and 0.25% ropivacaine 0.3 ml∕kg was given in group R. The emergence time was recorded, and the development of agitation was observed immediately after emergence from anes?thesia. Sensory block duration, motor block duration, consumption of sedatives and analgesics during post?anesthesia care unit(PACU), consumption of rescue analgesics within 24 h after operation, length of stay in PACU and adverse reactions in the perioperative period were observed and recorded. Results Compared with group R, the incidence of agitation immediately after emergence from anesthesia was significantly de?creased, sensory block duration was prolonged, the consumption of sedatives and analgesics during PACU and rescue analgesics within 24 h after operation was reduced, and the emergence time and length of stay in PACU were prolonged in group DR(P<0.05). There was no significant difference in the incidence of bradycardia between the two groups(P>0.05). No adverse reactions were found in the perioperative period in the two groups. Conclusion Dexmedetomidine can promote postoperative outcomes in pediatric patients undergoing open reduction and internal fixation following upper limb fracture performed under sevoflurane anesthesia combined with brachial plexus block.

The sympathetic block of upper limb leading to increased blood flow has important clinical implication in microvascular surgery. However, little is known regarding the relationship between concentration of local anesthetic and blood flow of upper limb. The aim of this dose–response study was to determine the ED50 and ED95 of ropivacaine in blood flow after supraclavicular block (SB).

IntroductionPostoperative delirium (POD) is a common serious postoperative complication especially in older people and is associated with increased mortality, morbidity and healthcare costs. There is no clear consensus which anaesthesia is associated with less incidence of POD for older patients. We aim to assess whether regional anaesthesia results in lower incidence of POD comparing with general anaesthesia (GA) among older patients undergoing hip fracture surgery.Methods and analysisRAGA-delirium is a pragmatic, multicentre, prospective, parallel grouped, randomised controlled clinical trial comparing RA or GA for hip fracture surgery. A total of 1000 patients who are 65 years or over and who are having planned hip fracture surgery in nine clinical trial centres of China will be randomised in a 1:1 ratio to receive either anaesthesia for the surgery. The primary endpoint will be the incidence of POD at day 7. The secondary endpoints will be the subtype, severity and duration of delirium, postoperative acute pain score, incidence of other postoperative non-delirium complications, quality of life and cost-effective outcomes. Randomisation will be performed at the patient level using computer-generated assignment. Outcome assessors will be blinded from intervention assignment. Assessments will be conducted before surgery, intraoperatively, postoperatively, during the hospital stay, at 30-day, 6-month and 1-year postoperative intervals.Potential impact of studyThis study will provide clinical evidence with a more robust methodology to help anaesthetists in selecting appropriate anaesthesia for older patients with high risk for POD. At the era of increasing emphasis on delirium prevention, this trial has the potential to inform the future national guideline to reduce POD.Ethics and disseminationEthical approved by the local institutional review board. Trial results will be presented at national and international academic conferences, and published in peer-reviewed journals.Trial registration numberClinicalTrials.gov (NCT02213380); pre-results.

Editor, Brachial plexus block (BPB) can lead to vasodilatation and increased blood flow in the ipsilateral arm,1 which could be beneficial for vascular re-construction2 and severe forearm ischaemia.3 However, it is not known which specific nerves among the musculocutaneous, radial, ulnar and median nerves innervate the radial and ulnar arteries. We therefore conducted a randomised controlled trial to identify which nerve block would lead to an increase in blood flow through the radial and ulnar arteries. This double-blind randomised controlled study was approved by the Institutional Review Board of the Second Affiliated Hospital and Yuying Children Hospital of Wenzhou Medical University, 109 Xueyuang xi Road, Wenzhou, China [Ref 2009(002), 2 February 2009, Chairman Professor Qinquan Lian] and was registered at Clinicaltrials.gov with the identifier NCT02139982 on 28 May 2014. Between March and December 2012, patients undergoing upper limb surgery were screened for inclusion in the trial. Informed consent was obtained from each patient included in the study. Eligible patients were randomly assigned to one of four groups according to selective nerve blockade (SNB) of the brachial plexus [Group MC (musculocutaneous), Group UL (ulnar), Group RA (radial) and Group ME (median)] using computer-generated (Microsoft Excel 2010) random numbers placed in sealed envelopes. Patients received a selective nerve block (MC, UL, RA or ME) in the axillary region using ultrasound combined with neurostimulation, and 5 ml of ropivacaine 0.5% (Naropin, Astra-Zeneca, Sweden) were injected. Thirty minutes after SNB, when all study data had been captured, all patients receive scheduled axillary BPB for surgery; the other three nerves of the axillary brachial plexus were blocked with the same method of SNB. A separate study investigator, blinded to the protocol and patient allocation, completed the haemodynamic measurements at all-time points: before insertion of blockade (baseline, T0), 30 min after SNB (T2) and 30 min after the entire brachial plexus had been blocked (T3). Time-averaged maximum velocity (TAMAX) and cross-sectional area (CSA) of the ulnar and radial artery were measured 1 cm proximal to the ulnar or radial styloid process using Pulsed-wave Doppler ultrasound and B-mode imaging (DC-6, Mindray Medical International Limited, China). Blood flow (BF) was calculated from the formula BF = TAMAX × CSA × 60. The relative change in regional blood flow was calculated from the formula ΔBF = (BFT1−BFT0)/(BFT2−BFT0). Our pilot study that showed the mean ± SD radial and ulnar artery blood flow increased three-fold (from 33.3 ± 19.5 to 102.1 ± 54.5 ml min−1) when measured 30 min after SNB or BPB. We estimated that six patients in each group would give the study a power of 80% (P < 0.05). Data are presented as mean ± SD or median (Inter-Quartile Range). Results were compared using Kruskal-Wallis H nonparametric test for relative change in regional blood flow among different groups and repeated measures analysis for the measurements at different time points. Statistical significance was defined as P < 0.05. Seventy six patients were screened, 35 patients were eligible and three patients did not give informed consent. Consequently, 32 patients were included in the study. Relative changes in regional blood flow are shown in Fig. 1. The greatest relative change of blood flow through the radial artery occurred in Group ME (P < 0.05). The changes in Group RA were less (P < 0.05) and there were no significant changes in Groups MC or UL. Relative change of blood flow through the ulnar artery in Group UL was greater than in the other three groups (P < 0.05); there were no significant changes in groups MC, ME or RA. In summary, median nerve block resulted in a greater increase in blood flow through the radial artery than did radial nerve block, and only ulnar nerve block increased blood flow through the ulnar artery (Fig. 1).Fig. 1: Box and whisker plots showing relative changes of blood flow in the four groups of selective nerve block. Values represent median, IQR and range. * P < 0.05 compared with other three groups. # P < 0.05 compared with groups MC and UL. MC, musculocutaneous nerve block; UL, ulnar nerve block; RA, radial nerve block; ME, median nerve block.Our study data showed that only the median nerve block resulted in a significant increase of the CSA of the radial artery and only the ulnar nerve block resulted in increased CSA of the ulnar artery, indicating that the radial artery may be innervated by only the median nerve, whereas the ulnar artery is innervated only by the ulnar nerve. Previous anatomical studies in the forearm demonstrated that the radial artery receives branches from the median nerve,4 superficial branch of the radial nerve or lateral antebrachial cutaneous5 nerve and that the ulnar artery receives a branch of the ulnar nerve.4 However, a study by Lange et al.6 measured the temperature of skin after SNB and reached the same conclusion as ours. The exact pathway of sympathetic innervation to the radial artery remains unclear and further research is required. Blocking the median or ulnar nerve specifically may be beneficial for micro-vascular surgery to produce vasodilatation and increased blood flow. The limitations of our study are that maximum haemodynamic effects of SNB may not be achieved 30 min after SNB or BPB, and we do not know whether SNB causes a slight effect on the sympathetic fibres of neighbouring nerves. In conclusion, selective ulnar and median nerve block resulted in arterial vasodilatation, an increase in blood flow velocity and blood flow through the ulnar artery and radial artery, respectively. Selective radial nerve block resulted in only a slight increase in blood flow through the radial artery. Selective musculocutaneous nerve block did not change the haemodynamics of either artery. Acknowledgements relating to this article Assistance with the study: we would like to thank Professor Weiyang Gao, Head of Hand Surgery, for designing this study. Financial support and sponsorship: this work was funded by the Health and Family Planning Commission of Zhejiang Province, China, Grant No. 2009A145 and The Recruitment Program of Global Experts, China. Conflict of interest: none.

OBJECTIVE:To evaluate the efficacy of ultrasound guidance for ilioinguinal or iliohypogastric nerve block in pediatric outpatients undergoing inguinal surgery.METHODS:The present study was approved by the ethics committee of our hospital. One hundred children with ASA status I, aged 4 - 8 years old, scheduled for unilateral inguinal surgery were randomly divided into ultrasound group (Group U) and traditional group (Group T) (n = 50 each). Upon entering operation room, they were monitored by electrocardiography (ECG), heart rate (HR) and oxygen saturation (SpO(2)). After an induction of general anesthesia, intravenous access was established and laryngeal mask inserted with spontaneous breathing. Intraoperative anesthesia was maintained with 2% sevoflurane in 50% nitrous oxide with 50% oxygen. Children in Group U received an ilioinguinal or iliohypogastric block under ultrasonic guidance with a mixture of 0.8% lidocaine and 0.25% levobupivacaine at 0.2 ml/kg while those in Group T performed according to the traditional method of anatomical localization with the same local anesthetic at 0.3 ml/kg. During surgery, the vital signs of HR, respiratory rate (RR), SpO(2), partial pressure of end-tidal carbon dioxide (P(ET)CO(2)) and exhaled sevoflurane concentration were recorded. Additional intraoperative analgesic requirements were recorded. Face legs activity cry consolability (FLACC) score was used to assess the pain score postoperatively at recovery time, 2 and 4 h postoperation respectively. If the pain score was above 3, the child received acetaminophen rectally. The number of postoperative rectal acetaminophen was recorded. The degrees of parental satisfaction were investigated at 2 and 4 h postoperation. Intra-or postoperative adverse events were also recorded.RESULTS:HR at skin incision and sac traction in Group U was significantly lower than those in Group T (P < 0.05). Six children (12%) needed to increase inhaled sevoflurane concentration during operation in Group U versus 17 (34%) in Group T (P < 0.05). The pain score at recovery time, 2 and 4 h postoperation in Group U was significantly lower than those in T group (P < 0.05). Only 4 children (8%) needed postoperative rectal acetaminophen in Group U versus 13 (26%) in Group T (P < 0.05). The degree of parental satisfaction at 2 h postoperation was significantly higher in Group U than that in Group T (P < 0.05). One case in Group T had needle puncturing into blood vessels. No other adverse event was observed in two groups.CONCLUSION:The method of ultrasonic guidance for ilioinguinal or iliohypogastric nerve block is both feasible and effective. It can not only enhance the effect of nerve block, reduce the occurrences of complications, lower the quantity of local anesthetic and alleviate the medicinal toxicity.

Background Ultrasound has been widely applied in clinical anesthesia and increasingly used in pediatric regional anesthesia.Objective Ultrasound can locate the target nerve by using the real-time imaging method,and enable the anesthetists to visualize the various anatomical structures directly arid observe the needle depth and the spread of local anesthetics during pediatric nerve block,so it enhances the safety and effectiveness in pediatric nerve block and reduces complications.Content Current research focuses on the procedure of ultrasound guided pediatric nerve block and the characteristics of ultrasonography,also understands the basic principles of ultrasound and the advantages of its application in pediatric regional anesthesia.Trend Ultrasound will become an indispensable tool for regional anesthesia,initiating a new direction in pediatric anesthesia.