Kevin Armstrong

Effect of stylet angulation and endotracheal tube camber on time to intubation with the GlideScope

PurposeThe GlideScope® videolaryngoscope usually provides excellent glottic visualization, but directing an endotracheal tube (ETT) through the vocal cords is sometimes difficult. The goal of the study was to determine which of two ETT angles (60°vs 90°) and cambers (forwardvs reverse) was better, as determined by time to intubation (TTI).MethodsTw o hundred patients requiring orotracheal intubation for elective surgery were randomly allocated to one of four groups: A) 90° angle, forward camber; B) 90° angle, reverse camber; C) 60° angle, forward camber; D) 60° angle, reverse camber. Time to intubation was assessed by a blinded observer. Operators were blinded until the point of intubation. A visual analogue scale (VAS) assessed the ease of intubation. The number of intubation attempts, number of failures, glottic grades, and use of external laryngeal manipulation were recorded.ResultsThe angle of the ETT had an impact on TTI but camber did not. The 90° angle demonstrated a 13% faster TTI than the 60° angle (47.1 ± 21.2 secvs 54.4 ± 28.2 sec,P = 0.042), and it resulted in easier intubation (VAS 16.4 ± 14.2 mmvs 27.3 ± 23.5 mm,P = 0.0001). The overall incidence of a grade 1 or 2 Cormack-Lehane glottic view was 99%.ConclusionsIn a heterogeneous group of operators and patients intubated with the GlideScope®, a 90° ETT angle provided the best result and should be the initial configuration. The camber of the ETT does not affect the time to intubation.RésuméObjectifLe vidéo-laryngoscope GlideScope® offre en général une excellente visualisation glottique; toutefois, il est parfois difficile d’orienter la sonde endotrachéale (SET) entre les cordes vocales. Le but de cette étude était de déterminer lequel de deux angles de SET (60° vs 90°) et quelle cambrure (avant vs arrière) étaient les meilleurs, déterminés selon le temps requis pour l’intubation (TRI).MéthodesDeux cents patients nécessitant une intubation oro-trachéale pour une chirurgie réglée ont été répartis en quatre groupes de façon aléatoire: a) angulation de 90°, cambrure avant; b) angulation de 90°, cambrure arrière; c) angulation de 60°, cambrure avant; d) angulation de 60°, cambrure arrière. Le temps requis pour l’intubation était estimé par un observateur ignorant le groupe d’allocation. Les opérateurs ont été tenus ignorants du groupe d’allocation jusqu’à l’intubation. Une échelle visuelle analogique (VAS) permettait d’estimer la facilité d’intubation. Le nombre de tentatives d’intubation, d’échecs, les grades glottiques ainsi que l’utilisation de manipulation laryngée externe étaient notés.RésultatsL’angulation de la SET a eu un impact sur le TRI mais pas la cambrure. Avec une angulation de 90°, le TRI était de 13% plus rapide qu’avec une angulation de 60° (47,1 ± 21,2 sec vs 54,4 ± 28,2 sec, P = 0,042), et l’ intubation était plus facile (VAS 16,4 ± 14,2 mm vs 27,3 ± 23,5 mm, P = 0,0001). L’incidence globale d’une visualisation glottique Cormack-Lehane de grade I ou 2 a été de 99 %.ConclusionsDans un groupe hétérogène d’opérateurs et de patients intubés avec le GlideScope®, une angulation de la SET de 90° offre le meilleur résultat et devrait être la configuration initiale. La cambrure de la SET n’affecte pas le temps requis pour l’intubation.

Brachial plexus anesthesia compared to general anesthesia when a block room is available

PurposeRegional anesthesia is often felt to be beneficial to patient care but detrimental to operating room (OR) efficiency. In this report we compare how a block room (BR) affects OR time (ORT) utilization for brachial plexus anesthesia (BPA) in a busy upper limb practice. We also compare how anesthetic technique, BPA or general anesthesia (GA), impacts on the time to recovery and discharge in patients having outpatient upper limb surgery.MethodsWith the Ethics Committee’s approval, a prospective study using hospital databases was undertaken. All patients presenting for surgery on the upper limb between November 1999 and April 2000 were eligible for analysis. A comparison was made of the various time intervals that comprise a patient’s hospital stay for either GA or BPA. Demographic data (ASA, age, outpatient status), and location of BPA were analyzed.ResultsUse of the BR for BPA significantly reduced the pre-procedure anesthesia ORT when compared to BPA done in the OR (11.4vs 32.9 min,P < 0.05; GA pre-procedure time was 17.8 min). In the ambulatory patient, BPA alone reduced post procedure anesthesia ORT, postanesthetic care unit, surgical day care unit, and total hospital times when compared to those receiving GA. On average those receiving a BPA spent 1.5 hr less in hospital (P < 0.01). Additionally, fewer admissions (2.4vs 5.4%) occurred in the BPA group.ConclusionThe use of a BR reduces the anesthesia ORT associated with BPA. Secondly, BPA improves the recovery time phase of outpatients undergoing surgery on the upper limb.RésuméObjectifL’anesthésie régionale semble souvent bénéficier au patient, mais nuire à l’efficacité de la salle d’opération (SO). Nous montrons comment la présence d’une salle de bloc (SB) influence le temps d’utilisation de la SO (TSO) pour l’anesthésie du plexus brachial (APB) dans un centre où les opérations des membres supérieures sont nombreuses. Aussi, comment la technique anesthésique, l’APB ou l’anesthésie générale (AG), agit sur le temps de récupération et de séjour à l’hôpital en chirurgie ambulatoire des membres supérieurs.dMéthodeUne étude prospective a été réalisée, avec l’accord du Comité d’éthique, à partir des bases de données de l’hôpital. Tous les cas opérés aux membres supérieurs entre novembre 1999 et avril 2000 ont été soumis à notre analyse. Nous avons comparé les divers intervalles de temps compris dans le séjour d’un patient qui a reçu une AG ou une APB. Les caractéristiques des patients (état physique ASA, l’âge, le statut ambulatoire) et l’endroit où a été fait l’APB ont été analysés.RésultatsL’APB réalisée en SB a réduit le TSO anesthésique préopératoire de façon significative, comparé à l’APB réalisée en SO (11,4 vs 32,9 min, P < 0,05; le temps préopératoire d’une AG a été de 17,8 min). Chez le patient ambulatoire, l’APB a réduit à elle seule le TSO anesthésique postopératoire, le temps en salle de réveil et à l’unité de chirurgie d’un jour, et le temps de séjour total en comparaison avec le patient d’AG. En moyenne, avec l’APB on passe 1,5 h de moins à l’hôpital (P < 0,01). En outre, il y a moins d’hospitalisation (2,4 vs 5,4 %) avec l’APB.ConclusionL’utilisation d’une SB réduit le TSO anesthésique associé à l’APB. De plus, l’APB réduit le temps de récupération des patients de chirurgie ambulatoire des membres supérieurs.

A comparison of glidescope videolaryngoscopy to direct laryngoscopy for nasotracheal intubation.

BACKGROUND: In this study, we compared the effectiveness of direct laryngoscopy (DL) and the GlideScope® videolaryngoscope (GVL) for nasotracheal intubation, as judged by the time to intubation (TTI—the primary outcome) and the ease of intubation. METHODS: Seventy patients requiring nasotracheal intubation for elective surgery were randomly allocated to intubation with the GVL or DL. TTI was assessed by a blinded observer. Operators were blinded until the start of laryngoscopy. A Visual Analog Scale assessed the ease of intubation. The number of intubation attempts, number of failures, glottic grades, amount of bleeding, usage of Magill forceps, and the severity of postoperative sore throat were recorded. RESULTS: The median TTI was 23.2 s faster with the GVL (43.5 s, interquartile range [IQR]: 39.8–67.3) than with DL (66.7 s, IQR: 53.8–89.9), P = 0.0023. Nasotracheal intubation was easier with the GVL than with DL (Visual Analog Scale 10 mm, IQR: 5.5–18, vs 20 mm, IQR: 10–32, P = 0.0041). The incidence of postoperative moderate or severe sore throat was significantly reduced in the GVL group (9% vs 34%, P = 0.018). Glottic exposure was significantly better with the GVL. Magill forceps were not used in the GVL group, but were used 49% of the time in the DL group, P < 0.0001. The incidence and severity of bleeding were similar between groups. CONCLUSIONS: Compared with DL, the GVL has superior performance characteristics when used for nasotracheal intubation and demonstrates an important reduction of postoperative sore throat. The GVL has a clear role in routine nasotracheal intubation.

A prospective, randomized, double-blind comparison of ultrasound-guided axillary brachial plexus blocks using 2 versus 4 injections.

INTRODUCTION:In this prospective, randomized, double-blind study, we compared the effectiveness and time efficiency of perioperative axillary blocks performed via 2 different techniques, 1 involving 2 and the other 4 separate skin punctures. METHODS:One hundred twenty patients undergoing upper limb surgery were randomized to receive either (1) an axillary brachial plexus block involving 2 injections, with 30 mL local anesthetic injected posterior to the axillary artery (with redirection, as needed, to achieve circumferential spread), plus 10 mL local anesthetic to the musculocutaneous nerve, guided by ultrasound (group 1, n = 56); or (2) 4 separate 10-mL injections to the median, ulnar, radial, and musculocutaneous nerves, using a combined ultrasound and neurostimulation technique (group 2, n = 58). All patients received 40 mL of 0.5% ropivacaine with 1:400,000 epinephrine. The primary outcome was the success rate of the block, defined as anesthesia adequate for surgery. Secondary outcomes were the time to administer the block, time to the onset of motor-sensory block, time to surgical readiness, and incidence of adverse events. RESULTS:The 2-injection technique was slightly faster to administer (8 vs 11 minutes, P = 0.003). The mean nerve block score was slightly higher for the 4-injection group at the 10-, 15-, 20-, and 30-minute time points, but the cumulative percentages of blocks having taken effect were not significantly different over these time points, at 0.0%, 5.4%, 12.5%, and 37.5% among those who had received a 2-injection block versus 6.9%, 10.4%, 19.0%, and 48.3%, respectively, with the 4-injection block (P = 0.20). There was no difference in the percentage of patients with complete block by 30 minutes (32.1% vs 37.5%, P = 0.55) or in final block success rates (89.3% vs 87.9%, P = 0.99). CONCLUSIONS:An ultrasound-guided 2-injection axillary block may be as effective as, and more time efficient than, a 4-injection technique.

Epinephrine reduces the sedative side effects of epidural sufentanil for labour analgesia

PurposeThe use of opioids in labour analgesia has primarily been as an adjuvant to local anesthetics. For early labour, satisfactory analgesia with epidural sufentanil alone is possible. This study evaluates the impact of epinephrine on sedative side effects and analgesia related to the latter technique.MethodsAfter Institutional Review Board approval and informed consent this prospective, randomized, double-blind study evaluated 43 nulliparous subjects requesting epidural analgesia. The study site, a tertiary care obstetric unit, accommodates 3500–4500 deliveries annually. Group selection was randomized and blinded by selection of a sealed envelope containing a number which corresponded to a premixed labelled syringe of saline or epinephrine (100 μg·mL−1). An epidural catheter was placed in a standardized fashion. All subjects received 40 μg of sufentanil and 0.5 mL from the premixed syringe, diluted to 10 mL with NaCl. A blinded observer collected data on maternal sedation, lightheadedness, hemodynamics, oxygenation, and fetal heart rate over a one-hour period following sufentanil injection.ResultsThe addition of epinephrine significantly (P < 0.05) reduced the incidence of sedation and lightheadedness after epidural sufentanil at all data collection points, except two. Analgesic duration was also significantly prolonged by this addition (120 ± 56 vs 84 ± 32 min). Maternal satisfaction was high regardless of solution. Conclusion: Forty micrograms of epidural sufentanil produces satisfactory analgesia in early labour. The addition of epinephrine improves the side effect profile of this technique while prolonging the duration of analgesia. Epidural sufentanil requires attention to maternal monitoring of oxygenation as maternal desaturation occurred in both groups.RésuméObjectifL’usage des opioïdes pour l’analgésie obstétricale a d’abord été un auxiliaire des anesthésiques locaux. Une analgésie satisfaisante peut être obtenue avec du sufentanil épidural employé seul au début du travail obstétrical. La présente étude évalue l’impact de l’épinéphrine sur les effets secondaires sédatifs et l’analgésie reliés à cette dernière technique.MéthodeAprès avoir obtenu l’accord du Comité de révision de l’hôpital et le consentement éclairé des participantes, l’étude prospective, randomisée et à double insu a évalué 43 femmes nullipares nécessitant une analgésie épidurale. L’étude s’est déroulée dans une unité obstétricale tertiaire où ont lieu de 3 500 à 4 500 naissances chaque année. La sélection des groupes a été faite au hasard et l’objectivité était assurée par une enveloppe scellée contenant un nombre correspondant à une seringue identifiée d’une solution salée ou d’épinéphrine déjà préparée (100 μg·mL− 1). Un cathéter épidural a été inséré de façon standardisée. Tous les sujets ont reçu 40 μg de sufentanil et 0,5 mL du mélange de la seringue, dilué à 10 mL avec du NaCl. Pendant une heure après l’injection de sufentanil, un observateur impartial a recueilli les données sur la sédation de la mère, les étourdissements, l’hémodynamique et la fréquence cardiaque fœtale.RésultatsL’ajout d’épinéphrine a significativement réduit (P < 0,05) l’incidence de sédation et les étourdissements après l’administration épidurale de sufentanil et tous les paramètres notés, sauf deux. La durée de l’analgésie a aussi été prolongée de façon significative par cet ajout (120 ± 56 vs 84 ± 32 min). La satisfaction des mères a été importante sans égard à la solution utilisée.ConclusionQuarante microgrammes de sufentanil épidural produisent une analgésie satisfaisante au début de l’accouchement. L’ajout d’épinéphrine améliore le profil des effets secondaires et prolonge la durée de l’analgésie. L’administration épidurale de sufentanil exige un monitorage attentif de l’oxygénation maternelle, la désaturation étant survenue dans les deux groupes.

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.

Waveform analysis for lumbar epidural needle placement in labour

References 1. Rosenfeld DM, Ivancic MG, Hattrup SJ, et al. Perineural versus intravenous dexamethasone as adjuncts to local anaesthetic brachial plexus block for shoulder surgery. Anaesthesia 2016; 71: 380–8. 2. Desmet M, Braems H, Reynvoet M, et al. IV and perineural dexamethasone are equivalent in increasing the analgesic duration of a single shot interscalene block with ropivacaine for shoulder surgery: a prospective, randomized, placebo-controlled study. British Journal of Anaesthesia 2013; 111: 445–52. 3. Kawanishi R, Yamamoto K, Tobetto Y, et al. Perineural but not systemic low-dose dexamethasone prolongs the duration of interscalene block with ropivacaine: a prospective randomized trial. Local and Regional Anesthesia 2014; 7: 5–9. 4. Desmet M, Vanneste B, Reynvoet M, et al. A randomized controlled trial of intravenous dexamethasone combined with interscalene brachial plexus blockade for shoulder surgery. Anaesthesia 2015; 70: 1180–5. 5. Woo JH, Kim YJ, Kim DY, et al. Dosedependency of dexamethasone on the analgesic effect of interscalene block for arthroscopic shoulder surgery using ropivacaine 0.5%: a randomised controlled trial. European Journal of Surgery 2015; 32: 650–5. 6. Yadeau JT, Gordon MA, Goyitzolo EA, et al. Buprenorphine, clonidine, dexamethasone, and ropivacaine for interscalene nerve blockade: a prospective randomized, blinded, ropivacaine doseresponse study. Pain Medicine 2016; 17: 940–60.

A Primer on Local Anesthetics for Plastic Surgery

This article provides some insight into the basic science and concepts relevant to the use of local anesthetics by clinicians in the management of their patients, including a brief history of the development of local anesthetics and their physical properties, effectiveness, uses, limitations, and safety considerations. A generalized overview of the mechanism of action is also provided. The molecular detail of local anesthetics and voltage-gated ion channels can form the basis of understanding of (1) future developments in this area, and (2) toxicity. Most of the peer-reviewed literature related to this topic stems from work in adult humans and animals.

Preprocedural ultrasound assessment does not improve trainee performance of spinal anesthesia for obstetrical patients: a randomized controlled trial

STUDY OBJECTIVE This randomized controlled trial was designed to evaluate the efficacy of additional information from preprocedure ultrasound examination to aid anesthesiology trainees performing spinal anesthesia for obstetric patients. DESIGN Trainee residents were randomly allocated to landmark technique and anatomy demonstration via ultrasound examination or landmark technique only for spinal anesthetic placement. SETTING Obstetric delivery suite. PATIENTS Eighty healthy obstetric patients undergoing elective cesarean delivery. INTERVENTION Ultrasound examination prior to spinal anesthetic placement. MEASUREMENTS The primary outcome was the number of attempts for the spinal anesthetic. Secondary outcomes included placement duration; block height; and the incidence of need for staff intervention, paresthesia, and bloody tap. Subjective ease of placement was rated on a 100-mm visual analog scale. MAIN RESULTS Baseline demographic data were similar between the patient groups. The median number of attempts with preprocedure ultrasound and landmark was 3 (interquartile range, 2-7). This was not significantly different from the number of attempts with landmark technique only of 3 (1-60) (P=.69). The median duration of spinal placement with ultrasound and landmark was 92 (51-140) seconds vs 75 (53-126) seconds with landmark only (P=.57). There was no statistical difference between the groups in spinal placement duration, need for staff intervention, paresthesia, bloody tap, lumbar interspace, or block height. There was no difference in subjective ease of spinal placement by the resident. CONCLUSIONS In this study of junior anesthesia trainees performing obstetrical spinal anesthesia with preprocedure ultrasound and landmark technique or landmark technique only, no significant difference was observed in the number of attempts, duration of spinal placement, subjective ease of spinal placement, or any other measured secondary outcome.