Paidrig M. 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.

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.

The GlideScope®-specific rigid stylet and standard malleable stylet are equally effective for GlideScope® use

PurposeThe GlideScope® videolaryngoscope usually provides excellent glottic visualization, but directing an endotracheal tube (ETT) through the vocal cords can be challenging. The goal of the study was to compare the dedicated GlideScope®-specific rigid stylet to the standard malleable stylet, assessed by time to intubation (TTI).MethodsEighty patients requiring orotracheal intubation for elective surgery were randomly allocated to either the GlideScope® rigid stylet (GRS) or a standard malleable stylet to facilitate intubation using the GlideScope®. Time to intubation was recorded by blinded assessors; operators were blinded until after laryngoscopy. The operator assessed the ease of intubation using a visual analogue scale (VAS). The number of intubation attempts, number of failures, glottic grades, and use of external laryngeal manipulation were documented.ResultsThe median TTI was 42.7 sec (inter-quartile range (IQR) 38.9-56.7) for the GRS group compared to 39.9 sec (IQR 34.1-48.2) for the control group (P = 0.07). The median VAS score for ease of intubation was 20 (IQR 12.0-33.0) for the GRS group compared to 18 (IQR 9.5-29.5) for the control group (P = 0.21). There was no significant difference in TTI or VAS between stylets. The overall incidence of a Cormack-Lehane grade I or II glottic view was 98%.ConclusionsIn a group of experienced operators using the GlideScope®, the dedicated GRS and the standard malleable ETT stylet are equally effective in facilitating endotracheal intubation.RésuméObjectifLe vidéolaryngoscope GlideScope® fournit en général une excellente visualisation glottique, mais diriger une sonde endotrachéale (SET) entre les cordes vocales peut être un défi. L’objectif de cette étude était de comparer le mandrin rigide spécifique au GlideScope® au mandrin flexible standard, évalués par le temps requis pour l’intubation (TTI).MéthodeQuatre-vingts patients nécessitant une intubation orotrachéale pour une chirurgie élective ont été randomisés à être intubés à l’aide soit du mandrin rigide GlideScope® (GRS), soit du mandrin flexible standard pour faciliter l’intubation avec le GlideScope®. Le temps requis pour l’intubation a été mesuré par des évaluateurs en aveugle; les opérateurs étaient également en aveugle jusqu’à ce que la laryngoscopie soit terminée. L’opérateur a évalué la facilité d’intubation à l’aide d’une échelle visuelle analogique (EVA). Le nombre de tentatives d’intubation, le nombre d’échecs, le grade d’intubation et le recours à une manipulation laryngée externe ont été notés.RésultatsLe TTI médian était de 42,7 sec (intervalle interquartile (IQR) 38,9-56,7) pour le groupe GRS comparé à 39,9 sec (IQR 34,1-48,2) pour le groupe témoin (P = 0,07). Le score EVA médian pour la facilité d’intubation était de 20 (IQR 12,0-33,0) pour le groupe GRS comparé à 18 pour le groupe témoin (P = 0,21). Il n’y a pas eu de différence significative dans le TTI ou l’EVA entre les mandrins. L’incidence globale de la visualisation glottique selon l’échelle de Cormack-Lehane de grade I ou II était de 98 %.ConclusionDans un groupe d’opérateurs expérimentés se servant du GlideScope®, le mandrin GRS spécial et le mandrin flexible standard ont la même efficacité pour faciliter l’intubation endotrachéale.

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.

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.

Epidural blood patch treatment for headache caused by a ruptured Tarlov cyst

To the Editor, Tarlov cysts are cerebrospinal fluid (CSF)-containing nerve root cysts that arise between the perineurium and the endoneurium near the dorsal root ganglion. They are found most often in the sacral roots and, rarely, cause symptoms related to nerve root compression. The literature is limited when it comes to the management of these ruptured cysts. We recently treated a previously healthy 24-yr-old woman (who consented to this report) who was admitted to the hospital with a severe headache. She had become symptomatic six hours after slipping on ice and falling on her coccyx. Her symptoms included bilateral frontoparietal headache that was more severe in the sitting position and reduced in intensity when recumbent. There was nausea but no vomiting. There were no signs or symptoms of infection. Her physical and plain radiographic examinations and a non-contrast cerebral computed tomography (CT) scan were unremarkable. Magnetic resonance imaging (MRI) of the brain showed smooth dural enhancement, mild distention of the dural venous sinuses, and a slight decrease in the suprasellar cistern – all of which supported a diagnosis of intracranial hypotension. Subsequent MRI scans of the entire spine showed Tarlov cysts in the sacrum (Figure). Although no definitive CSF leak was identified, considering the patient’s symptoms and cerebral radiological findings of intracranial hypotension, a ruptured cyst was presumptively diagnosed. The patient was initially treated conservatively with acetaminophen, ibuprofen, and hydromorphone. However, 48 hr later, her symptoms remained. Following a multidisciplinary discussion – with input from neurology, radiology, and anesthesia – the collaborative conclusion was that the patients’ headache was due to a ruptured Tarlov cyst, and some relief might result from an epidural blood patch (EBP). The radiological opinion was that the S1-S3 nerve roots were the most likely site of the CSF leak. Following the patient’s consent, pre-procedural ultrasonography was performed to identify the L5-S1 interspace. The EBP was then undertaken with the patient in sitting position. A 17G epidural needle was inserted, using loss of resistance with air to identify the epidural space (3.5 cm from the skin). The bevel of the epidural needle was directed caudally to target the sacral area. At that point, 25 mL of the patient’s blood was injected, with sterile precautions, into the epidural space. She was then kept supine for an hour. Her headache diminished significantly after the EBP, and she was discharged from the hospital the same day. Follow-up on days five, 20, and 42 revealed no additional headache. Patients with Tarlov cysts are commonly asymptomatic. Trauma, however, can damage the cyst, resulting in CSF leak and a typical positional headache due to intracranial hypotension, similar to the headache caused by post-dural puncture. The diagnosis is aided by MRI of the brain and spine. Data regarding the management of ruptured Tarlov cysts are insufficient. The postural headache that followed rupture of the cyst and the resolution of symptoms following EBP suggests that intracranial hypotension secondary to the CSF leak is a likely explanation. The injected blood may help seal the leak and increase epidural pressure, which, in turn, elevates subarachnoid CSF pressure by compressing the dura. It appears that EBP is F. Qasem, MBBCh, MD (&) C. McCallum, ACNP, GDipNPAC P. Armstrong, MD, FRCPC Department of Anesthesia & Perioperative Medicine, University of Western Ontario, London, ON, Canada e-mail: fatemahq82@gmail.com

Anesthetic considerations in a parturient with Freeman–Sheldon syndrome

Freeman-Sheldon syndrome is a rare genetic disorder characterized by malformations of the face, oral cavity and musculoskeletal system. This case report describes the anesthetic management of a parturient with Freeman-Sheldon syndrome, kyphoscoliosis and a cardiac pacemaker for a cesarean delivery and tubal ligation. With a predicted difficult airway, our team decided to provide a combined spinal-epidural anesthetic. Problems encountered included difficult intravenous access, failure to identify the subarachnoid space and patient discomfort during surgery.

Ultrsound guided axillary brachial plexus block: single vs triple injection

Ultrasound-guided axillary brachial plexus block: single versus triple injection. Introduction: Axillary brachial plexus block is a common anesthetic technique for distal upper extremity surgery. A recent meta-analysis has shown that multiple injections are more effective than single injection. (1) Ultrasound guidance has become popular for performance of brachial plexus blocks and is associated with excellent anesthesia (2). In this prospective, randomized, double blind clinical trial we compared the effects of a single injection versus triple injection on the onset time and quality of sensory and motor block using ultrasound in patients having axillary block for surgery. Methods: Following Research Ethics Board approval and written informed consent,88 adult patients undergoing upper limb surgery were randomized to one of two groups: group A received 30mls of local anesthetic posterior to the artery, at the 6 o’clock position and group B received 10mls of local anesthetic, at the 11 o’clock, 4 o’clock and 6 o’clock positions corresponding to the locations of the median, ulna and radial nerves respectively.All blocks were done using 0.5% ropivacaine with epinephrine 1:400,000. In all patients, the musculocutaneous nerve was blocked separately with 10mls of local anesthetic . Total procedure time and time to complete motor and sensory block was noted by a blind observer. Patients with incomplete blocks at 30 minutes were supplemented and this was noted. Results: Demographics were similar between groups. (Table 1). The time to perform the block was 3 minutes faster in group A (p = 0.015, t-test). There was no difference in the time to ready for surgery (40.0 min in group A vs. 44.2 min in group B). Both techniques were associated with high success rates (88.1% in group A vs. 89.1% in group B). Data were analysed with SAS 9.1 software. Conclusion: In summary, when using ultrasound guidance for axillary brachial plexus block, single injection posterior to the artery (at the 6 o’clock position) is performed faster than triple injection with no difference in subsequent sensory and motor block quality.