Shalini Dhir

Comparative evaluation of ultrasound-guided continuous infraclavicular brachial plexus block with stimulating catheter and traditional technique: a prospective-randomized trial

Background: Secondary catheter failure has been reported in up to 40% of patients with continuous peripheral nerve blocks resulting in failure to provide pain relief after the initial block wears off. Introduction of stimulating catheters as well as ultrasound for regional anaesthesia has facilitated correct placement of catheter tip, closer to the plexus. This randomized study was conducted to compare the efficacy of continuous infraclavicular brachial plexus blocks using non‐stimulating catheter, stimulating catheter and ultrasound‐guided catheter placement with nerve stimulation assistance.

Use of ultrasound guidance and contrast enhancement: a study of continuous infraclavicular brachial plexus approach*

Purpose: We describe our experience of combining the use of ultrasound (US) guidance with contrast enhancement and peripheral nerve stimulation for the insertion of infraclavicular brachial plexus catheters.

Case report : Ropivacaine neurotoxicity at clinical doses in interscalene brachial plexus block

PurposeTo describe a case of ropivacaine toxicity following an ultrasound guided interscalene block and discuss the possible mechanisms involved.Clinical featuresA 76-yr-old woman with multiple myeloma was scheduled for open reduction and internal fixation following a pathological fracture of her left upper humerus. She developed central nervous system toxicity with ropivacaine 15 min after a carefully placed ultrasound-guided interscalene catheter. The dose of ropivacaine was within recommended limits and there was no evidence that the catheter was intravascular. Surgery proceeded uneventfully under general anesthesia. The interscalene catheter was left in situ for postoperative evaluation and intravascular injection was ruled out with a colour Doppler study. The total ropivacaine plasma concentration was 3.68 μg·mL-1. Neurological evaluation, contrast computerized tomography and electroencephalogram were normal. The patient was discharged home with no sequelae. Advanced age, malnutrition, epinephrine and possible elevation of α-1-acid glycoprotein levels could have altered the pharmacokinetics of plasma ropivacaine and possibly contributed to delayed neurotoxicity.ConclusionsLocal anesthetic toxicity is an uncommon but well documented complication of regional anesthesia. Careful monitoring and preparedness for managing complications during the conduct of regional anesthesia cannot be overemphasized. Experience from this case suggests that local anesthesia toxicity can happen within safe dose limits and without intravascular placement despite careful attention to needle and catheter placement, fractionated dosing and frequent aspirations.RésuméObjectifDécrire un cas de toxicité à la ropivacaïne suite à un bloc interscalénique écho-guidé et examiner les mécanismes possibles impliqués.Eléments cliniquesUne réduction ouverte et une fixation interne ont été prévues chez une patiente âgée de 76 ans souffrant de myélome multiple, à la suite d’une fracture pathologique de son humérus supérieur gauche. Elle a développé une toxicité impliquant le système nerveux central avec de la ropivacaïne 15 min après le positionnement d’un cathéter interscalénique placé avec soin grâce à un écho-guidage. La dose de ropivacaïne se situait dans les limites recommandées et il n’y avait aucune indication que le cathéter était intravasculaire. La chirurgie a eu lieu sans incident sous anesthésie générale. Le cathéter interscalénique a été laissé in situ à des fins d’évaluation postopératoire, et la possibilité d’une perfusion intravasculaire a été écartée par une étude Doppler couleur. La concentration plasmatique de ropivacaïne totale était de 3,68 μg·mL-1. L’évaluation neurologique, la tomographie de contraste par ordinateur et l’électroencéphalogramme étaient normaux. La patiente est rentrée chez elle sans séquelles. L’âge avancé, la malnutrition, l’épinéphrine et une élévation possible des niveaux de glycoprotéine acide α-1 ont pu modifier la phar-macocinétique de la ropivacaïne et possiblement contribuer à une neurotoxicité retardée.ConclusionLa toxicité d’un anesthésique local est une complication peu commune mais bien documentée de l’anesthésie régionale. Une surveillance soignée et une capacité de réaction pour la prise en charge de complications pendant l’anesthésie régionale ne peuvent être suffisamment recommandées. Ce cas suggère que la toxicité d’une anesthésie locale peut survenir même dans les limites sécuritaires de dosage et sans positionnement intravasculaire, malgré une attention particulière au positionnement de l’aiguille et du cathéter, un dosage fractionné et des aspirations fréquentes.

A Comparison of Combined Suprascapular and Axillary Nerve Blocks to Interscalene Nerve Block for Analgesia in Arthroscopic Shoulder Surgery: An Equivalence Study.

Background and Objectives The primary objective of this study was to compare the analgesic efficacy of combined suprascapular and axillary nerve block (SSAX) with interscalene block (ISB) after arthroscopic shoulder surgery. Our hypothesis was that ultrasound-guided SSAX would provide postoperative analgesia equivalent to ISB. Methods Sixty adult patients undergoing arthroscopic shoulder surgery received either SSAX or ISB prior to general anesthesia, in a randomized fashion. Pain scores, satisfaction, and adverse effects were recorded in the recovery room, 6 hours, 24 hours, and 7 days after surgery. Results Combined suprascapular and axillary nerve block provided nonequivalent analgesia when compared with ISB at different time points postoperatively, except on postoperative day 7. Interscalene block had better mean static pain score in the recovery room (ISB 1.80 [95% confidence interval [CI], 1.10–2.50] vs SSAX 5.45 [95% CI, 4.40–6.49; P < 0.001]). At 24 hours, SSAX had better mean static pain score (ISB 6.35 [95% CI, 5.16–7.54] vs SSAX 3.92 [95% CI, 2.52–5.31]; P = 0.01) with similar satisfaction between the groups. Conclusions Combined suprascapular and axillary nerve block provides nonequivalent analgesia compared with ISB after arthroscopic shoulder surgery. While SSAX provides better quality pain relief at rest and fewer adverse effects at 24 hours, ISB provides better analgesia in the immediate postoperative period. For arthroscopic shoulder surgery, SSAX can be a clinically acceptable analgesic option with different analgesic profile compared with ISB.

Efficacy of ultrasound-guided transversus abdominis plane blocks for post-cesarean delivery analgesia: a double-blind, dose-comparison, placebo-controlled randomized trial

BACKGROUND The analgesic benefit of TAP (transversus abdominis plane) blocks for cesarean delivery pain remains controversial. We compared the analgesic efficacy of two doses of local anesthetic for TAP blocks after cesarean delivery. METHODS Sixty women having cesarean delivery under spinal anesthesia were randomized to receive ultrasound-guided TAP blocks using either high-dose ropivacaine (3mg/kg), low-dose ropivacaine (1.5mg/kg) or placebo. Patients received intrathecal 0.75% bupivacaine 10-12mg, fentanyl 10μg and morphine 150μg and standard multimodal analgesia. The primary outcome was the difference in pain with movement using a numeric rating scale at 24h. Other outcomes included time to first request for analgesia, pain scores at 6, 12, 36, 48h and at 6 and 12weeks, opioid consumption, adverse effects, quality of recovery, and satisfaction. RESULTS There were no differences between groups in the primary outcome. Mean ± SD pain scores (0-10) with movement at 24h were: high-dose ropivacaine 3.6±1.5, low-dose ropivacaine 4.6±2.1 and placebo 4.1±1.7. With respect to secondary outcomes, the mean ± SD pain scores at 6h were lower in the high-dose group 2.0±1.8 compared to the low-dose 3.4±2.7 and placebo groups 4.2±2.0 (P=0.009). Pain scores at 12h were also lower in the high-dose group 2.2±2.0 compared to the low-dose group 4.1±2.7 and placebo group 4.0±1.3 (P=0.011). There was no difference in other outcomes between groups. CONCLUSIONS Neither high- or low-dose TAP blocks as part of a multimodal analgesia regimen including intrathecal morphine improved pain scores with movement at 24h after cesarean delivery when compared to placebo TAP blocks. High-dose TAP blocks may improve pain scores up to 12h after cesarean delivery.

Ultrasound-guided peripheral regional blockade in patients with Charcot-Marie-Tooth disease: a review of three cases.

Purpose: To describe the clinical presentation of three patients with Charcot-Marie-Tooth disease, who underwent uneventful upper limb surgery following successful peripheral nerve blockade, and to review the anesthetic implications in patients with Charcot-Marie-Tooth disease.Clinical features: In three patients with Charcot-Marie-Tooth disease presenting for surgery of the upper limb, the motor response, following nerve stimulation, was suboptimal. However, ultrasound guidance was effective in visualizing the needle-nerve interaction, and local anesthetic was injected around the nerves. Good block ensued and surgery proceeded in all patients without complications. No exacerbation of the neurological condition was observed in any patient.Conclusions: Charcot-Marie-Tooth disease is a demyelinating, hereditary, motor and sensory neuropathy characterized by abnormalities of nerve conduction. Regional anesthesia of the upper limb is feasible in these patients, and these cases show that ultrasound guidance makes peripheral nerve block possible in patients for whom traditional methods of nerve localization fail.RésuméObjectif: Décrire la présentation clinique de trois patients souffrant de la maladie de Charcot-Marie-Tooth subissant une chirurgie d’un membre supérieur sans complications à la suite la mise en place réussie d’un bloc des nerfs périphériques, et réitérer les implications anesthésiques chez les patients souffrant de la maladie de Charcot-Marie-Tooth.Éléments cliniques: Dans le cas de trois patients souffrant de la maladie de Charcot-Marie-Tooth se présentant pour une chirurgie d’un membre supérieur, la réaction motrice était sous-optimale après stimulation nerveuse. Cependant, l’échoguidage a permis de visualiser l’interaction entre l’aiguille et le nerf, et un anesthésique local a été injecté autour des nerfs. Ainsi, un bloc efficace a été réalisé et la chirurgie s’est déroulée sans complications chez les trois patients. Aucune exacerbation de l’état neurologique n’a été observée chez ces patients.Conclusions: La maladie de Charcot-Marie-Tooth est une neuropathie sensori-motrice héréditaire due à une démyélinisation et caractérisée par des anomalies au niveau de la conduction nerveuse. L’anesthésie régionale des membres supérieurs est réalisable chez les patients souffrant de cette maladie, et les cas présentés ici montrent que l’échoguidage permet une anesthésie des nerfs périphériques chez les patients chez lesquels les méthodes conventionnelles de localisation des nerfs échouent.

Case report: pregnancy in hemodialysis-dependent end-stage renal disease: anesthetic considerations.

PurposeTo describe the obstetrical and anesthetic management of a parturient with end-stage renal disease.Clinical featuresA 38-yr-old woman had severe renal impairment due to Wegener’s granulomatosis. She was on hemodialysis for 12 years following two failed kidney transplants. She had two unsuccessful pregnancies, two and 12 years previously. The antenatal care of the present pregnancy incorporated a multidisciplinary approach involving obstetrics, nephrology and anesthesiology. Labour was induced at 36 weeks gestation. Bupivacaine 0.0625% with fentanyl 2 μg·mL-1 was injected through an epidural catheter inserted for labour analgesia. Lidocaine 2% with epinephrine 2.5 μg·mL-1 was given later for Cesarean delivery. There was no associated maternal or neonatal morbidity. The management focused on minimizing hemodynamic disturbances while providing maximum pain relief.ConclusionsFor a successful outcome in the parturient with end-stage renal disease, a multidisciplinary approach is essential.ObjectifDécrire la prise en charge obstétricale et anesthésique d’une parturiente souffrant d’insuffisance rénale terminale.Éléments cliniquesUne femme de 38 ans souffrait d’une insuffisance rénale sévère secondaire à une granulomatose de Wegener. Elle avait été hémodyalisée pendant 12 ans, suite à l’échec de deux transplantations rénales, et avait eu deux grossesses infructueuses, deux et 12 ans auparavant. La prise en charge anténatale de la grossesse actuelle a donc nécessité une approche pluridisciplinaire, incluant les services d’obstétrique, de néphrologie et d’anesthésiologie. Le travail obstétrical a été induit à 36 semaines de grossesse. De la bupivacaïne 0,0625 % et du fentanyl 2 μg·mL-1 ont été injectés via un cathéter péridural inséré pour l’analgésie du travail obstétrical. De la lidocaïne 2 % et de l’épinéphrine 2,5 μg·mL-1 ont été administrés plus tard lors de l’accouchement par césarienne. Il n’y a pas eu de morbidité maternelle ou néonatale associée. La prise en charge a eu comme objectifs de minimiser l’instabilité hémodynamique tout en fournissant un soulagement maximal de la douleur.ConclusionUne approche pluridisciplinaire est essentielle dans la prise en charge d’une parturiente souffrant d’insuffisance rénale terminale.

Programmed intermittent peripheral nerve local anesthetic bolus compared with continuous infusions for postoperative analgesia: A systematic review and meta-analysis

STUDY OBJECTIVE AND BACKGROUND The role of the programmed intermittent bolus (PIB) technique for infusion of local anesthetics in continuous peripheral nerve blockade (CPNB) remains to be elucidated. Randomized controlled trials (RCTs) on PIB versus continuous infusion for CPNB have demonstrated conflicting results and no systematic review or meta-analysis currently exists. We aimed to delineate via systematic review with meta-analysis if there is any analgesic benefit to performing PIB versus continuous infusion for CPNB. DESIGN We conducted a systematic review and random-effects meta-analysis of RCTs. DATA SOURCES We searched Medline, Embase, and the Cochrane Library without language restriction from inception to 2-May-2017. ELIGIBILITY CRITERIA Included RCTs had to compare PIB to continuous infusion in adult surgical patients receiving any upper or lower limb CPNB for postoperative analgesia. VAS pain scores were the primary outcome. The Cochrane Risk of Bias Tool with GRADE methodology was utilized to assess evidence quality. RESULTS Nine RCTs (448 patients) met the inclusion criteria. Two studies performed upper limb blocks and the rest lower limb blocks. Five RCTs activated the CPNB with long-acting local anesthetic and only five used multi-modal analgesia. PIB modestly reduced VAS pain scores at 6h (-14.2mm; 95%CI -23.5mm to -5.0mm; I2=82.5%; p=0.003) and 12h (-9.9mm; 95%CI -14.4mm to -5.4mm; I2=12.4%; p<0.001), but not at later time points. There were no other meaningful differences in the rest of the outcomes, apart from more residual motor block with PIB (OR 4.27; 95% CI 1.08-16.9; p=0.04; NNTH=8). GRADE scoring ranged from low to very low. CONCLUSIONS The existing evidence demonstrates that PIB does not meaningfully reduce VAS pain scores in CPNB. This systematic review provides important information about the limitations of existing studies. Future studies should reflect contemporary practice and focus on more painful operations.

A randomised comparison between ultrasound and nerve stimulation for infraclavicular catheter placement

We conducted this study to determine if placement of infraclavicular catheters guided by ultrasound is quicker than placement guided by nerve stimulation. Infraclavicular brachial plexus catheters were inserted in 210 randomly allocated patients who were scheduled for elective hand or elbow surgery. Needle and catheter placement was guided by ultrasound (n = 105) or by nerve stimulation (n = 105). The primary outcome was time to sensory block success. Success rate was similar between the two techniques (83.2% vs 81.4%, p = 0.738). However, placement of ultrasound‐guided catheters took less time (7.2 [2.5] vs 9.6 [3.6] min, p < 0 .001). Pain and satisfaction scores, and incidence of nerve deficit, were also similar with both techniques.

Comparative evaluation of the visibility and block characteristics of a stimulating needle and catheter vs an echogenic needle and catheter for sciatic nerve block with a low-frequency ultrasound probe

BACKGROUND Clear visibility of the needle and catheter tip is desirable to perform safe and successful ultrasound-guided peripheral nerve blocks. This can be challenging with deeper blocks in obese patients. This study compared the visibility of echogenic and non-echogenic block needles and catheters in proximal sciatic blocks when performed with a low-frequency curved probe. METHODS Seventy-eight patients undergoing total knee joint arthroplasty were randomized to receive an ultrasound-guided continuous sciatic nerve block using either a non-echogenic needle and stimulating catheter or an echogenic needle and echogenic non-stimulating catheter. Block needles in both groups were placed using both neurostimulation and ultrasound guidance, after which the catheter was positioned using either neurostimulation alone (Stimulating group) or imaging alone (Echogenic group). Three anaesthetists blinded to group allocation graded video clips recorded during the blocks for nerve, needle and catheter visibility. Performance characteristics and block parameters were also compared. RESULTS No significant differences between the two groups were observed with regard to needle or catheter visibility (P=0.516). The Stimulating group required more needle redirections (P=0.009), had a longer procedure time [Echogenic median 274 s vs Stimulating 344 s (P=0.016)], and resulted in greater patient discomfort (P=0.012). There were no significant differences between the two groups in terms of block onset or completion time. CONCLUSIONS Use of echogenic needles and catheters reduced procedure time and patient discomfort compared with a stimulating catheter system. There were no differences in the visibility scores of the two systems. CLINICAL TRIAL REGISTRATION CTR Protocol ID: R-11-495, Clinical Trials.Gov ID: NCT 01492660.