Stephan R Williams

Centre hospitalier de l'Université de Montréal (CHUM), Montréal, Quebec, Canada

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Publications (9)33.1 Total impact

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    ABSTRACT: Tracheal intubation of an unstable cervical spine (c-spine) patient with the flexible fiberoptic bronchoscope (FOB) is thought to minimize c-spine movement but may be technically difficult in certain patients. Intubation using a luminous stylet, such as the Trachlight(R) (TL), also produces minimal motion of the c-spine and may be an interesting alternative technique for patients with an unstable c-spine. In this study, we compared the cervical motion caused by the TL and the FOB during intubation. Twenty patients with a normal c-spine undergoing general anesthesia, including neuromuscular blockade, for a neuroradiologic intervention were included in a prospective, randomized, controlled, nonblinded, crossover trial. Each patient was tracheally intubated sequentially with the TL and the FOB in a randomized order. Manual in-line stabilization was applied by an assistant during intubation. The motions produced by intubation from the occiput (C0) to C5 were recorded in the sagittal plane using continuous cinefluoroscopy. For movement analysis, the recordings were divided into four stages: "baseline" before intubation began; "introduction" of the intubation device; "intubation" (passage of the tube through the vocal cords); and "removal" of the device. For each intubating device, the average maximal segmental motion observed in every patient at any stage or cervical segment was calculated and compared using Student's t-test. The time required to intubate with each device was also compared. There was no significant difference in the mean maximum segmental motion produced during intubation with the TL versus the FOB (12 degrees +/- 6 degrees vs 11 degrees +/- 5 degrees ; P = 0.5). Segmental movements occurred predominantly at the C0-1 and C1-2 levels, and maximal movements were observed during the introduction stage in 18/20 patients for both devices. Intubation took less time with the TL (34 +/- 17 vs 60 +/- 15 s, P < 0.001). In patients under general anesthesia with neuromuscular blockade and manual in-line stabilization, we found no difference in the segmental c-spine motion produced during endotracheal intubation using the FOB and the TL.
    Anesthesia and analgesia 05/2009; 108(5):1638-43. · 3.08 Impact Factor
  • Christian Loubert, Stephan R Williams
    Anesthesiology 01/2009; 109(6):1144. · 5.16 Impact Factor
  • Anesthesiology 05/2008; 108(4):759-60. · 5.16 Impact Factor
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    ABSTRACT: The optimal tracheal intubation technique for patients with potential cervical (C) spine injury remains controversial. Using continuous cinefluoroscopy, we conducted a prospective study comparing C-spine movement during intubation using direct laryngoscopy (DL) or GlideScope videolaryngoscopy (GVL), with uninterrupted manual in-line stabilization of the head by an assistant. Twenty patients without C-spine pathology were studied. After induction of general anesthesia with neuromuscular blockade, both DL and GVL were performed on every patient in random order. Cinefluoroscopic images of C-spine movement during GVL and DL were acquired and divided into four stages: a baseline image before airway manipulation, glottic visualization, insertion of the endotracheal tube into the glottis, and tracheal intubation. Peak segmental motion from the occiput to C5 was measured offline for each patient and each stage, averages were calculated, and movements induced by each instrument were compared using a two-way ANOVA. Also studied were the proportion of patients with occiput-C1 rotation exceeding 10, 15, or 20 degrees, and the quality of glottic visualization. No significant difference was found between DL and GVL regarding average segmental spine movement at any level (P values between 0.22 and 0.70). During both techniques, motion was mainly an extension concentrated in the rostral C-spine and occurred predominantly during glottic visualization. The proportion of patients with occiput-C1 extension of more than 10, 15, or 20 degrees was not significantly different. Glottic visualization was significantly better with GVL compared with DL. During intubation under general anesthesia with neuromuscular blockade and manual in-line stabilization, the use of GVL produced better glottic visualization, but did not significantly decrease movement of the nonpathologic C-spine when compared with DL.
    Anesthesia and analgesia 04/2008; 106(3):935-41, table of contents. · 3.08 Impact Factor
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    ABSTRACT: Up to 70% of patients report moderate to severe pain after shoulder surgery, which can compromise early rehabilitation and functional recuperation. Postoperative shoulder pain control is improved with both interscalene block and intra-articular local anesthetic injection. The present study hypothesized that perioperative interscalene analgesia would offer pain control superior to perioperative intra-articular local anesthetics over the first 24 hours after surgery. Sixty patients undergoing shoulder surgery were randomly assigned to 1 of 2 groups: group IS had interscalene block with catheter installation, while group IA received intra-articular local anesthetic, also with catheter installation. All patients received 3 local anesthetic injections: 0.25 mL/kg of 2% lidocaine with epinephrine 2.5 microg/mL immediately before and after surgery, and 0.25 mL/kg of 0.5% bupivacaine with epinephrine 2.5 microg/mL 1 hour after the end of surgery, after which the catheters were removed, and no further local anesthetics were administered. Postoperative pain at rest was evaluated in the postanesthesia care unit (PACU), 3 hours, 6 hours and 24 hours after surgery. The area under the 24 hour pain over time curve was calculated. Hydromorphone consumption in the PACU and over 24 hours was recorded. Pain scores (IS: 0.4 +/- 2 vs. IA: 4 +/- 3, P < .0001) and opioid consumption (IS: 0.7 mg +/- 1.4 vs. IA: 1.5 mg +/- 1.2, P = .02) were significantly higher in the PACU for group IA. However, neither the mean pain scores over the first day after surgery (IS: 5 +/- 2 vs. IA: 5 +/- 3; P = .4) nor 24-hour opioid consumption (IS: 4.4 mg +/- 2.8 vs. IA: 4.2 mg +/- 2.6; P = .4) were significantly higher in group IA. PACU measurements of immediate postoperative pain and narcotic consumption favor perioperative interscalene analgesia over intra-articular analgesia. This benefit does not translate into lower overall pain for the first 24 hours after surgery.
    Regional Anesthesia and Pain Medicine 01/2008; 33(2):134-8. · 3.46 Impact Factor
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    ABSTRACT: Ultrasound guidance (USG) for infraclavicular blocks provides real time visualization of the advancing needle and local anesthetic distribution. Whether visualization of local anesthetic spread can supplant neurostimulation as the end point for local anesthetic injection during USG block has never been formally evaluated. Therefore, for this prospective randomized study, we recruited 72 patients scheduled for hand or forearm surgery and compared the speed of execution and quality of USG infraclavicular block with either USG alone (Group U) or USG combined with neurostimulation (Group S). In Group U, local anesthetic was deposited in a U-shaped distribution posterior and to each side of the axillary artery using as few injections as possible (1, 2, and 3 injections in 29, 6, and 3 patients, respectively). In Group S, a single injection was made after obtaining a distal motor response with a stimulating current between 0.3 and 0.6 mA. The anesthetic solution consisted of 0.5 mL/kg of lidocaine 1.5%, bupivacaine 0.125%, and epinephrine 1:200 000 (final concentrations). Procedure times were significantly shorter in Group U compared with Group S (3.1 +/- 1.6 min and 5.2 +/- 4.7 min, respectively; P = 0.006). In Group S, anesthetic spread was mainly anterior to the axillary artery in 37% of patients and mainly posterior in 63% of patients. Thirty minutes after the injection, 86% of patients in Group U had complete sensory block in the musculocutaneous, median, radial, and ulnar nerve territories compared with 57% in Group S (P = 0.007). Patients blocked in Group U with a single injection had the same rate of complete block (86%) as those blocked with more than one injection (86%). Block supplementation rates were 8% in Group U versus 26% in Group S (P = 0.049). Block failure occurred in one patient in Group S because of an inability to obtain a distal stimulation after 20 min. We conclude that USG infraclavicular block is more rapidly performed and yields a higher success rate when visualization of local anesthetic spread is used as the end point for injection. Posterolateral spread of local anesthetic around the axillary artery predicts successful block, circumventing the need for direct nerve visualization.
    Anesthesia and analgesia 06/2007; 104(5):1275-80, tables of contents. · 3.08 Impact Factor
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    ABSTRACT: This prospective study compared the initial block quality and surgical anesthesia rates of ultrasound-guided infraclavicular blocks with local-anesthetic injected through a catheter versus through a needle. We hypothesized that positioning of the catheter immediately posterior to the axillary artery would produce through-the-catheter (TTC) anesthesia with rates of complete block not inferior to through-the-needle (TTN) injection. Eighty patients undergoing hand or forearm surgery extensive enough to require regional anesthesia were randomized into 2 groups of 40. In group TTN, local anesthetic was deposited posterior, lateral, and medial to the axillary artery using as few injections as necessary. In group TTC, a 20-gauge, multiorifice catheter was positioned between the posterior wall of the axillary artery and the posterior cord of the brachial plexus. All blocks were performed by use of ultrasound visualization with a 6-MHz to 10-MHz 38-mm linear probe. Local-anesthetic solution consisted of 0.5 mL/kg lidocaine 2% with epinephrine. Sensory and motor blocks, as well as supplementation rates, were evaluated for the musculocutaneous, median, radial, and ulnar nerves. Complete sensory block of all nerve territories was achieved in 92% of patients in group TTN and 90% in group TTC (P = .51). In group TTN, 90% of patients had satisfactory anesthesia for surgery (no discomfort and no need for anesthetic supplementation of any type) compared with 92% in group TTC (P = .51). Ultrasound-guided TTC infraclavicular block produced perioperative anesthesia that was not inferior to a TTN technique.
    Regional Anesthesia and Pain Medicine 01/2007; 32(4):296-302. · 3.46 Impact Factor
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    ABSTRACT: In this prospective study we compared ultrasound-guided (USG) infraclavicular and supraclavicular blocks for performance time and quality of block. We hypothesized that the infraclavicular approach would result in shorter performance times with a quality of block similar to that of the supraclavicular approach. Eighty patients were randomized into two equal groups: Group I (infraclavicular) and Group S (supraclavicular). All blocks were performed using ultrasound visualization with a 7.5-MHz linear probe and neurostimulation. The anesthetic mixture consisted of 0.5 mL/kg of bupivacaine 0.5% and lidocaine hydrocarbonate 2% (1:3 vol.) with epinephrine 1:200,000. Sensory block, motor block, and supplementation rates were evaluated for the musculocutaneous, median, radial, and ulnar nerves. Surgical anesthesia without supplementation was achieved in 80% of patients in group I compared with 87% in Group S (P = 0.39). Supplementation rates were significantly different only for the radial territory: 18% in Group I versus 0% in group S (P = 0.006). Block performance times were not different between groups (4.0 min in Group I versus 4.65 min in Group S; P = 0.43). Technique-related pain scores were not different between groups (I: 2.0; S: 2.0; P = 1.00). We conclude that USG infraclavicular block is at least as rapidly executed as USG supraclavicular block and produces a similar degree of surgical anesthesia without supplementation.
    Anesthesia & Analgesia 10/2005; 101(3):886-90, table of contents. · 3.30 Impact Factor
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    ABSTRACT: In this prospective study, we assessed the quality, safety, and execution time of supraclavicular block of the brachial plexus using ultrasonic guidance and neurostimulation compared with a supraclavicular technique that used anatomical landmarks and neurostimulation. It was hypothesized that ultrasonic guidance would increase the proportion of successful blocks, decrease block execution time, and reduce the incidence of complications such as pneumothorax and neuropathy. Eighty patients were randomized into two groups of 40, Group US (supraclavicular block guided in real time by a two-dimensional ultrasonic image, with neurostimulator confirmation of correct needle position) and Group NS (supraclavicular block using the subclavian perivascular approach, also with neurostimulator confirmation). Blocks were performed using bupivacaine 0.5% and lidocaine 2% (1:1 vol) with epinephrine 1:200000 as the anesthetic mixture. The onset of motor and sensory block for the musculocutaneous, median, radial, and ulnar nerves was evaluated over a 30 min period. At 30 min 95% of patients in Group US and 85% of patients in Group NS had a partial or complete sensory block of all nerve territories (P = 0.13) and 55% of patients in Group US and 65% of patients in Group NS had a complete block of all nerve territories (P = 0.25). Surgical anesthesia without supplementation was achieved in 85% of patients in Group US and 78% of patients in Group NS (P = 0.28). No patient in Group US and 8% of patients in Group NS required general anesthesia (P = 0.12). The quality of ulnar block was significantly inferior to the quality of block in other nerve territories in Group NS, but not in Group US; the quality of ulnar block was not significantly different between Groups NS and US. The block was performed in an average of 9.8 min in Group NS and 5.0 min in Group US (P = 0.0001). No major complication occurred in either group. We conclude that ultrasound-guided neurostimulator-confirmed supraclavicular block is more rapidly performed and provides a more complete block than supraclavicular block using anatomic landmarks and neurostimulator confirmation. IMPLICATIONS: Ultrasound-guided neurostimulator-confirmed supraclavicular block is more rapidly performed and provides a block of better quality than supraclavicular block using anatomic landmarks and neurostimulator confirmation.
    Anesthesia & Analgesia 11/2003; 97(5):1518-23. · 3.30 Impact Factor