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.

Comparison of a single-use GlideScope Cobalt videolaryngoscope with a conventional GlideScope for orotracheal intubation.

BACKGROUND: This study was conceived to compare the single-use GlideScope Cobalt videolaryngoscope with the conventional GlideScope videolaryngoscope for orotracheal intubation, as judged by time to intubation (TTI) and ease of intubation. METHODS: One hundred patients with normal-appearing airways requiring orotracheal intubation for elective surgery were randomly allocated to have their tracheas intubated by a heterogeneous group of operators with the Cobalt GlideScope or the conventional GlideScope. TTI was assessed by a blinded observer. Operators were blinded until the start of laryngoscopy. A visual analogue scale (VAS) assessed the ease of intubation. The number of intubation attempts, number of failures, glottic grades, and fogging of the video screen were recorded. RESULTS: There was no difference between the median TTI of the GlideScope Cobalt and the conventional GlideScope (40.1 sec, interquartile range [IQR] 34.1, 51.3 vs 39 sec, IQR 32.6, 48.1, respectively; P = 0.75). The ease of intubation was similar between the two devices (median Cobalt VAS: 16 mm, IQR 10.8, 27.3, vs median conventional VAS: 12.5 mm, IQR 10, 20.5, respectively; P = 0.12). There were no significant differences between the two devices with respect to glottic exposure, intubation attempts, failures, or video screen fogging. CONCLUSIONS: The GlideScope Cobalt has similar performance characteristics compared with the conventional GlideScope videolaryngoscope when used for orotracheal intubation. The two devices can likely be used interchangeably. (ClinicalTrials.gov number, NCT00459797.).

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.

PURPOSE: The 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). METHODS: Eighty 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. RESULTS: The 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%. CONCLUSIONS: In a group of experienced operators using the GlideScope, the dedicated GRS and the standard malleable ETT stylet are equally effective in facilitating endotracheal intubation.

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

PURPOSE: The 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 degrees vs 90 degrees ) and cambers (forward vs reverse) was better, as determined by time to intubation (TTI). METHODS: Two hundred patients requiring orotracheal intubation for elective surgery were randomly allocated to one of four groups: A) 90 degrees angle, forward camber; B) 90 degrees angle, reverse camber; C) 60 degrees angle, forward camber; D) 60 degrees 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. RESULTS: The angle of the ETT had an impact on TTI but camber did not. The 90 degrees angle demonstrated a 13% faster TTI than the 60 degrees angle (47.1 +/- 21.2 sec vs 54.4 +/- 28.2 sec, P=0.042), and it resulted in easier intubation (VAS 16.4 +/- 14.2 mm vs 27.3 +/- 23.5 mm, P=0.0001). The overall incidence of a grade 1 or 2 Cormack-Lehane glottic view was 99%. CONCLUSIONS: In a heterogeneous group of operators and patients intubated with the GlideScope, a 90 degrees ETT angle provided the best result and should be the initial configuration. The camber of the ETT does not affect the time to intubation.