Comparison of the effects of perineural or intravenous dexamethasone on low volume interscalene brachial plexus block: a randomised equivalence trial.

BACKGROUND: Efforts to prolong interscalene block (ISB) analgesia include the use of local anaesthetic adjuvants such as dexamethasone. Previous work showing prolonged block duration suggests that both perineural and intravenous (i.v.) routes can both prolong analgesia. The superiority of either route is controversial given the design of previous studies. As perineural dexamethasone is an off-label use, anaesthesiologists should be fully informed of the clinical differences, if any, on block duration. This study was designed to test whether perineural vs i.v. dexamethasone administration are equivalent. METHODS: We randomised 182 eligible patients scheduled for arthroscopic shoulder surgery to receive low-dose ISB (0.5% ropivacaine 5 ml) with perineural or i.v. dexamethasone 4 mg. Subjects, anaesthesiologists, and research personnel were blinded. All subjects also received a standardised general anaesthetic and multimodal analgesia. The primary outcome was duration of analgesia analysed as an equivalence outcome (2 h equivalency margin) using the two one-sided test (TOST) method. RESULTS: For the primary outcome, duration of analgesia, and perineural and i.v. administration of dexamethasone were not equivalent. The upper and lower bounds of the 90% confidence interval were 1 h (P=0.12) and -2.5 h (P=0.01), respectively. The observed difference in mean block duration was not clinically relevant (0.75 h longer for i.v. dexamethasone). There were no other clinically significant differences between groups. CONCLUSION: In the context of low-volume ISB with ropivacaine, perineural and i.v. dexamethasone were not equivalent in terms of their effects on block duration. However, there were no clinically significant differences in outcomes, and there is no advantage of perineural over intravenous dexamethasone. WWW.CLINICALTRIALS. GOV REGISTRATION: NCT02322242.

Correction to: Neuraxial anesthesia and bladder dysfunction in the perioperative period: a systematic review.

The following row on page 691 of Table 3, as highlighted in bold under Incidence of Retention (%) should read "0" instead of "N/A".

Low-dose spinal bupivacaine for total knee arthroplasty facilitates recovery room discharge: a randomized controlled trial.

PURPOSE: Regional anesthesia is the preferred technique for total knee arthroplasty to provide a bridge for early postoperative analgesia, reduce opioid consumption, and improve mobility and rehabilitation. Multiple patient and process factors must be weighed when choosing the appropriate technique to reduce morbidity and facilitate discharge. We hypothesized that a low-dose of intrathecal bupivicaine combined with regional block would facilitate discharge from the postanesthesia care unit (PACU) and reduce postoperative morbidity. METHODS: Patients undergoing total knee arthroplasty under spinal anesthesia received either 5 mg (low-dose group) or 10 mg (standard-dose group) isobaric bupivacaine in a double-blind randomized controlled trial. The primary outcome measure was time to achieve eligibility for PACU discharge. Secondary outcome measures included time to recovery of S2 dermatome sensation, time to voiding, rate of bladder catheterization, and time required for nursing intervention in the PACU and after discharge to the surgical ward. RESULTS: Forty-five of the 49 recruited patients completed the study. Patients receiving low-dose spinal anesthesia were eligible for PACU discharge earlier than those receiving the standard dose (P = 0.0036). Patients receiving the standard dose had significantly delayed recovery of S2 dermatome sensation (P = 0.0035). There was no difference between groups in the amount of time required for nursing intervention in the PACU, but patients receiving low-dose spinal anesthesia required more time for nursing intervention within the first four hours of their arrival on the ward (P = 0.009). None of the patients required intraoperative analgesic supplementation. CONCLUSIONS: In patients undergoing total knee arthroplasty, low-dose intrathecal bupivacaine (5 mg) combined with regional block is associated with a reduced time to achieve eligibility for discharge from the PACU.

Neuraxial anesthesia and bladder dysfunction in the perioperative period: a systematic review.

PURPOSE: Urinary retention requiring catheterization carries the risk of infection. Neuraxial anesthesia causes transient impairment of bladder function ranging from delayed initiation of micturition to frank urinary retention. We undertook a review of the literature to determine the elements of neuraxial anesthesia and analgesia that prolong bladder dysfunction and increase the incidence of urinary retention. METHODS: We performed a systematic search of the PubMed, MEDLINE, and EMBASE databases (from January 1980 to January 2011) to identify studies where neuraxial anesthesia and/or analgesia were employed and at least one of the following outcomes was reported: urinary retention, time to micturition, or post void residual. We included randomized controlled trials and observational studies published in the English language and we excluded case reports. The randomized trials were graded according to the Jadad score. PRINCIPAL FINDINGS: Our search yielded 94 studies, and in 16 of these studies, the authors reported time to micturition after intrathecal anesthesia of varying local anesthetics and doses. Intrathecal injections were performed in 41 of these studies, epidural anesthesia/analgesia was used in 39 studies, and five studies involved both the intrathecal and epidural routes. Meta-analysis was not possible because of the heterogeneity of interventions and reported outcomes. The duration of detrusor dysfunction after intrathecal anesthesia is correlated with local anesthetic dose and potency. The incidence of urinary retention displays a similar trend and is further increased by the presence of neuraxial opioids, particularly long-acting variants. Urinary tract infection secondary to catheterization occurred rarely. CONCLUSIONS: Neuraxial anesthesia/analgesia results in transient detrusor dysfunction. The duration of dysfunction depends on the potency and dose of medication used; however, it does not appear to result in significant morbidity.

A comparison of sartorius versus quadriceps stimulation for femoral nerve block: a prospective randomized double-blind controlled trial.

BACKGROUND: Femoral nerve block is widely used for regional anesthesia and analgesia in many lower limb operations. Peripheral nerve stimulation of the femoral nerve may elicit 1 of 2 responses: contraction of the sartorius muscle through stimulation of its muscular branch or contraction of the quadriceps muscle through stimulation of its respective muscular branches. Historically, a quadriceps response has been preferred. We hypothesized that the success of femoral nerve block using a sartorius muscle evoked motor response is equivalent to that using quadriceps muscle twitch response. This prospective randomized double-blind controlled trial compared sartorius or quadriceps muscle evoked motor response as the end point for stimulation for femoral nerve block. METHODS: Seventy-two patients scheduled for primary unilateral total knee arthroplasty were randomly assigned to undergo femoral nerve block using either the sartorius or the quadriceps evoked muscle response as an end point of stimulation. Motor block of the femoral and sensory block of the femoral, saphenous, and lateral femoral cutaneous nerves were assessed. The primary outcome was the quality of motor and sensory block of the femoral nerve 30 minutes after injection of 20 mL of 0.5% ropivacaine. Secondary outcomes were duration of femoral nerve block, time required to perform the nerve block, total dose of hydromorphone patient-controlled analgesia, and postoperative pain by visual analog score 24 hours after block insertion. In addition, the spread of local anesthetic and the position of the needle in relation to the femoral nerve were assessed by means of ultrasonography. RESULTS: There were no statistically significant differences in the proportion of patients with either complete alone or complete and partial block combined between quadriceps and sartorius groups 30 minutes after block insertion; femoral nerve (P = 0.49; P = 0.13), the saphenous nerve (P = 0.64; P = 0.21), or the lateral femoral cutaneous nerves (P = 0.2; P = 0.35). Patient-controlled analgesia hydromorphone consumption was significantly higher in the group that underwent sartorius muscle stimulation ([mean ± SD] 4.9 ± 3.6 mg [range, 0-13.2 mg] vs 3.1 ± 2.7 mg [range, 0-10.0 mg]; P = 0.024). CONCLUSION: Our study demonstrated that using sartorius or quadriceps evoked muscle twitch as an end point of stimulation was associated with an equivalent degree of femoral nerve block.

Ultrasound-guided blocks for shoulder surgery.

PURPOSE OF REVIEW: There have been several recent insights in our understanding of how best to provide optimal perioperative anesthesia and analgesia for ambulatory shoulder surgery. This review attempts to distill the advances reported in the past 12-18 months and put them in perspective. RECENT FINDINGS: Recent studies have explored the optimal dosing regimens and techniques for single-shot and continuous nerve blocks with regard to block effectiveness and complications. Further rigorously conducted studies into postoperative neurological and respiratory complications are correlated with study findings of brachial plexus anatomy. Evidence is presented supporting supraclavicular brachial plexus block as an equivalent alternative to interscalene block for ambulatory shoulder surgery. SUMMARY: Following recent findings it is likely that the use of supraclavicular block will become more popular for shoulder surgery. However, further large-scale trials will be needed to definitively prove its advantages over the traditional interscalene block. On the contrary, the precision of ultrasound guidance and the ongoing optimization of postoperative continuous anesthetic infusion regimens continue to improve the performance characteristics of interscalene block.

Anesthesia residents' preference for learning interscalene brachial plexus block (ISBPB): traditional Winnie's technique vs. ultrasound-guided technique.

There is a recent shift from traditional nerve stimulation (NS) to ultrasound-guided (UG) techniques in regional anesthesia (RA). This shift prompted educators to readdress the best way to teach these two modalities. Development of a more structured curriculum requires an understanding of student preferences and perceptions. To help in structuring the teaching curriculum of RA, we examined residents' preferences to the methods of instruction (NS Vs. UG techniques). Novice residents (n=12) were enrolled in this parallel crossover trial. Two groups of 6 residents received a didactic lecture on NS or UG techniques. The groups then crossed over to view the other lecture. After they observed a demo of ISBPB on two patients using NS and US. The residents completed a questionnaire regarding their impression of each technique and the learning experience. UG technique was perceived to be safer and to have more educational value than NS. However, residents felt both techniques should be mandatory in the teaching curriculum.

Acquisition of technical skills in ultrasound-guided regional anesthesia using a high-fidelity simulator.

Despite the increasing popularity of ultrasound-guided regional anesthesia (UGRA), structured training programs during residency are often lacking. The lack of a regional block area, lack of expertise, and lack of structured training programs have limited hands-on experience in residency programs. However, these constraints may be circumvented through the use of simulation. This observational study looked at the use of a high-fidelity simulator for training novice undergraduate students UGRA techniques. Despite some improvement in the second trial with the simulator, the ability to maintain visualization of their needle (p<0.05), align needle with probe (p<0.05), and angle their needle approach (p<0.05), as well as reduce needle passes (p<0.05) did not improve. The results show students had difficulty learning skills requiring more coordination and fine motor control.

Posterior interscalene block: an ultrasound-guided case series and overview of history, anatomy and techniques.

BACKGROUND: The posterior interscalene block has been described as an alternative to the lateral interscalene block. However, this technique has not gained popularity because of the close proximity of the approach to vascular and central neural structures. OBJECTIVE: To describe the posterior interscalene block technique using ultrasound imaging, and to review the history of its evolution. METHODS: The use of ultrasound imaging to facilitate the insertion of interscalene catheters using the posterior approach in 11 patients undergoing total shoulder arthroplasty is described. RESULTS: All 11 patients had satisfactory analgesia in the first 24 h of the postoperative period. None of the patients complained of neck pain, as had been found in earlier techniques using the posterior approach. CONCLUSIONS: This modification of the posterior approach is a safe and effective method for the insertion of interscalene brachial plexus catheters. These catheters are also comfortable for patients and, in the present study, none of the catheters inadvertently fell out.

The minimal effective volume (MEAV 95) for interscalene brachial plexus block for surgical anesthesia under sedation: A prospective observational dose finding study.

Background: Interscalene brachial plexus (ISB) block is routinely used to provide anesthesia and analgesia for shoulder surgery. Traditional local anesthetic volumes for ISB result in near universal ipsilateral phrenic nerve paresis potentially including oxygenation and ventilation. Aims: The purpose of this study was to determine the lowest minimal effective anesthetic volume in 95% of patients (MEAV 95) of ropivacaine 0.75% for ISB that provides surgical anesthesia for arthroscopic shoulder surgery. Methods: Prospective observational cohort study in patients undergoing arthroscopic shoulder surgery under ISB (C6 level) with sedation. The dose finding protocol used the Narayana rule for up/down sequential allocation to estimate the MEAV 95 of ropivacaine 0.75%. Successful ISB was defined as complete absence of pinprick sensation in the C5 and C6 dermatomes 30 min postblock. Secondary outcomes assessed included ability to complete surgery with propofol sedation, change in slow vital capacity, room air oxygen saturation postblock, block duration, ISB complications, and numeric rating scale for pain immediately after surgery. Results: The study was stopped early due to futility. Among 225 participants approached, 54 consented to participate. The MEAV 95 for ultrasound-guided ISB of ropivacaine 0.75% for shoulder surgery was unable to be accurately estimated. Local anesthetic volumes between 5 and 20 ml did not influence any of the predefined secondary outcomes. Conclusions: The MEAV 95 (at 30 min) of ropivacaine 0.75% for ultrasound-guided ISB exceeds the local anesthetic volumes that consistently produces hemidiaphragmatic impairment. ISB cannot be guaranteed to provide surgical anesthesia at 30 min without the potential for concomitant phrenic nerve block.

Contexte: Le bloc du plexus brachial par approche interscalénique (BIS) est régulièrement utilisé pour l'anesthésie et l'analgésie lors de chirurgies de l'épaule. Les volumes d'anesthésique local traditionnellement utilisés pour le BIS entraînent couramment une parésie ipsilatérale du nerf phrénique compromettant l'oxygénation et la ventilation.Objectifs: Le but de cette étude était de déterminer le plus petit volume minimal effectif chez 95% des patients (VME 95) de la ropivacaïne 0,75 % lorsqu'utilisé pour un BIS lors d'une chirurgie arthroscopique de l'épaule.Méthodes: Étude de cohorte prospective observationnelle auprès de patients subissant une chirurgie arthroscopique de l'épaule sous BIS (niveau C6) avec sédation. Le protocole d'identification du VME 95 de la ropivacaïne 0,75% a été effectué selon la règle de Narayana pour augmenter ou diminuer l'allocation séquentielle des doses. Un BIS réussi était défini comme l'absence totale de sensation de picotement dans les dermatomes aux niveaux C5 et C6 30 minutes après le bloc. Les critères d'évaluation secondaires comprenaient la capacité de compléter la chirurgie avec une sédation à base de propofol, les changements dans la capacité vitale lente, la saturation de l'oxygène de l'air ambiant après le bloc, la durée du bloc, les complications rencontrées avec le BIS et l'intensité de la douleur immédiatement après la chirurgie mesurée à l'aide d'une échelle numérique.Résultats: L'étude a été arrêtée avant terme en raison de son insuccès. Parmi les 225 patients approchés, 54 ont accepté d'y participer. Le VME 95 de la ropivacaïne 0,75 % pour un BIS écho-guidé lors d'une chirurgie de l'épaule n'a pu être estimé avec précision. Les volumes d'anesthésique local entre 5 et 20 ml n'ont influencé aucun des critères d'évaluation secondaires prédéfinis.Conclusions: Le VME 95 de la ropivacaïne 0,75 % (à 30 minutes) pour un BIS écho-guidé excède les volumes d'anesthésique local qui entraînent systématiquement une déficience au niveau du l'hémidiaphragme. Le BIS ne peut fournir une anesthésie de 30 minutes pour une chirurgie arthroscopique de l'épaule sans risque concomitant de bloquer le nerf phrénique.

Posterior lumbar plexus block: anatomy, approaches, and techniques.

Lumbar plexus is an effective but underused regional technique that was described nearly 3 decades ago. The original description has been modified several times based on advances in technology, localization, and imaging techniques. This review provides an overview of the history, anatomy, and techniques described to perform this block.

A comparison of the effects of droperidol and the combination of droperidol and ondansetron on postoperative nausea and vomiting for patients undergoing laparoscopic cholecystectomy.

STUDY OBJECTIVES: To compare the prophylactic antiemetic efficacy of the combination of ondansetron and droperidol with that of droperidol alone in patients undergoing elective laparoscopic cholecystectomy. DESIGN: Randomized, double-blind controlled trial. University affiliated teaching hospital after induction of standardized general anesthesia. PATIENTS: 64 ASA physical status I or II patients aged 18 to 80 years, undergoing elective laparoscopic cholecystectomy. INTERVENTION: Following induction of general anesthesia, patients received either droperidol 1.25 mg intravenously (IV; n = 30; Group D) or the combination of droperidol 1.25 mg IV and ondansetron 4 mg IV (n = 34; Group D+O). MEASUREMENTS: Number and severity of nausea episodes, number of emetic episodes, total analgesic consumption, and rescue antiemetic administration were assessed at 1, 3, and 24 hours after admission to the recovery room. Data were analyzed using Fisher's Exact test and unpaired Student's t-test; a p-value <0.05 was considered significant. RESULTS: The proportions of patients who experienced nausea (70% and 53% for D and D+O groups, respectively) and vomiting (30% and 19% for D and D+O groups, respectively) were similar in the two groups. The frequency of moderate and severe nausea (requiring administration of antiemetic) was less in group D + O (7%) compared with group D (19%; p < 0.05). CONCLUSIONS: Patients who received the combination of droperidol and ondansetron experienced less severe nausea compared with patients who received droperidol alone.

A scoping review of the evidence for teaching ultrasound-guided regional anesthesia.

A scoping review was performed to assess published evidence regarding how best to teach ultrasound-guided regional anesthesia (UGRA). The literature search yielded 205 articles, of which 35 met the inclusion criteria. Current literature on the topic can be divided into 3 main themes: the development of motor skills, learning and teaching sonoanatomy, and understanding of the requirements for establishing a UGRA education program and evaluation. We discuss the current status and future direction of research on UGRA training.

The creation of an objective assessment tool for ultrasound-guided regional anesthesia using the Delphi method.

BACKGROUND AND OBJECTIVES: The assessment of technical skills in ultrasound-guided regional anesthesia is currently subjective and relies largely on observations of the trainer. The objective of this study was to develop a checklist to assess training progress and to detect training gaps in ultrasound-guided regional anesthesia using the Delphi method. METHODS: A 30-item checklist was developed and then e-mailed to 18 reviewers for feedback. The checklist was modified on the basis of their feedback. This process of iteration was repeated until no further feedback was received, and a consensus was reached on the final composition of the checklist. A global rating scale (GRS) was introduced as a result of the feedback. RESULTS: Three rounds of feedback were required to reach consensus on the composition of the checklist and the GRS. The final checklist contains 22 items, and the GRS contains 9 categories. CONCLUSIONS: Using the Delphi method, a checklist and GRS were developed. These tools can serve as an objective means of assessing progress in ultrasound technical skills acquisition.

Ultrasound provides a reliable test of local anesthetic spread.

BACKGROUND AND OBJECTIVES: We predicted that practitioners could identify injectate spread in a model of ultrasound-guided peripheral nerve block. METHODS: Both novices and experts in ultrasound-guided peripheral nerve block were asked to recognize the spread of local anesthetic in a gelatin ultrasound phantom. In a blinded and randomized fashion, these participants were observed to either successfully or unsuccessfully state whether an injection had been made. RESULTS: Twelve novices and 8 experts each completed the trials. Accuracy, Sensitivity and specificity were calculated for all trials. Users attained a very high accuracy and sensitivity (> 85%) as well as specificity (> 90%) with ultrasound in this model. CONCLUSIONS: This study shows that ultrasound is a reliable method of detecting injectate spread in a gelatin phantom model.

Spinal epidural hematoma following epidural catheter removal in a paraplegic patient.

Spinal epidural hematoma is a rare and devastating complication of epidural catheter removal in an anticoagulated patient. The diagnosis could be quite challenging, especially in patients with preexisting neurological deficits. A 35-year-old patient with remote spinal cord injury and T4 level paraplegia developed a spinal epidural hematoma on the 7th postoperative day. The hematoma developed after epidural catheter removal with concurrent administration of unfractionated heparin.

Factors affecting recovery and discharge following ambulatory surgery.

PURPOSE: Recovery and discharge following ambulatory surgery are important components of the ambulatory surgery experience. This review provides contemporary perspectives on the issues of discharge criteria, fast-tracking, patient escort requirements, and driving after ambulatory anesthesia. SOURCE: A search was performed in the Cochrane Central Register for Controlled Trials, MEDLINE(R), EMBASE(R), CINAHL, and PsycINFO, to review factors delaying discharge following ambulatory surgery. The following subject headings were used: "ambulatory surgery, discharge, recovery, car driving, escort, transport, fast tracking, patient discharge, recovery, transportation of patients, hospital discharge, recovery room, patient transport, hospital discharge, recovery room, anesthetic recovery, patient transport, ambulatory surgical procedures, patient discharge, recovery of function, automobile driving, patient escort service, recovery room". Using the same search engines, the following keywords were used: "fast tracking, recovery, and discharge". PRINCIPAL FINDINGS: The current literature supports that discharge scoring systems may be useful to guide discharge following ambulatory surgery. While fast-tracking has become common in some centres, further studies are required to justify more routine implementation of this practice in the management of patients undergoing ambulatory surgery. Patients at low risk for urinary retention can be discharged home without voiding. Patients should not drive until at least 24 hr postoperatively. CONCLUSIONS: Ensuring rapid postoperative recovery and safe discharge following ambulatory surgery are important components of the ambulatory surgical program. A clearly defined process should be established for each ambulatory surgical unit to ensure the safe and timely discharge of patients after anesthesia, in accordance with current best evidence.