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Neonates and infants are prone to oxygen desaturation during the induction of general anethesia. Pharyngeal oxygen insufflation has been shown to delay the onset and severity of desaturation during apnea. We took this comparative study with the hypothesis that Oxiport Blade delays the time of onset as well as severity of desaturation as compared to Miller Blade. Eighty neonates and infants undergoing general anesthesia with endotracheal intubation were recruited and randomly assigned into two groups:-Oxiport or Miller. (Laryngoscopy performed with Oxiport or Miller Blade respectively). Results were observed in terms of lowest SPO2 attained during Intubation with each Blade, time for 1% desaturation from baseline, desaturation rate, time for intubation and Heart rate. Data from 80 patients were available for final analysis: Oxiport(n=40)-Group O and Miller(n=40)-Group M. Mean lowest SPO2 attained during laryngoscopy in Group O was 97.77±2.81 and with Group M was 92.42±3.71 with a P-value Apnoeic Laryngeal Oxygen insufflation with Oxiport Blade decreases the incidence and severity of desaturation during intubation in neonates and infants.

Background: Coronavirus disease 2019 (COVID-19) barrier box is being used by health-care workers for protection against aerosol-transmitted infection. Usually, a Macintosh laryngoscope (MC) or a video laryngoscope (VL) is used for endotracheal intubation (ETI). We aimed to determine the most suitable laryngoscope blade in terms of time to ETI, ease of ETI, and the first-pass success rate. Methods: American Society of Anesthesiologists Grade I and II patients undergoing surgery under general anesthesia were randomized into the MC and the King Vision VL groups in a 1:1 ratio. ETI was performed using either the MC (the MC group) or the King Vision VL (the VL group) with a COVID-19 barrier box. The first-pass intubation success rate, intubation time, and ease of ETI were analyzed. Results: The first-pass success rate was higher in the MC group (P = 0.43). The mean duration of ETI was 33 s and 47 s in the MC group and VL group, respectively. The difference was statistically significant between the groups (P = 0.002). The ease of ETI was comparable between the groups (P = 0.57), and the Cormack–Lehane grade was significantly different between the groups (P = 0.0025). Conclusion: ETI duration was shorter in the MC group than in the VL group. Hence, a MC can be used along with a COVID-19 barrier box by experienced operators for the prevention of aerosol spread.

During laryngoscopy, the laryngoscope blade sometimes comes in contact with the teeth, fracturing or dislocating them. However, no studies have compared the effects of newly marketed video laryngoscopes and the Macintosh laryngoscope (Mac) on teeth. In this study, we measured and compared the force exerted on the teeth of an intubating manikin by the Mac, the Airway Scope (Pentax), and the McGrath MAC (Covidien). The mean force exerted was 141.1 ± 15.7 kg by the Mac, 39.2 ± 10.3 kg by the Airway Scope, and 48.7 ± 6.7 kg by the McGrath MAC. No significant difference was observed between the Airway Scope and the McGrath MAC. When the Mac is inserted, the glottis has to be visually located from outside the oral cavity. However, a significant force is not necessary when inserting video laryngoscopes because a camera is mounted on the blade tip. In this laboratory model, the lower force exerted by the video laryngoscopes should contribute to a reduction in their impact on fracture or dislocation of teeth.

Author(s): Myers, BAH, Lucas A.; Gallet, BA, Charles G.; Kolb, DO, Logan J.; Lohse, MS, Christine M.; Russi, DO, Christopher S. | Abstract: Introduction: This study aimed to identify factors associated with successful endotracheal intubation (ETI) by a multisite emergency medical services (EMS) agency.Methods: We collected data from the electronic prehospital record for all ETI attempts made from January through May 2010 by paramedics and other EMS crew members at a single multistate agency. If documentation was incomplete, the study team contacted the paramedic. Paramedics use the current National Association of EMS Physicians definition of an ETI attempt (laryngoscope blade entering the mouth). We analyzed patient and EMS factors affecting ETI.Results: During 12,527 emergent ambulance responses, 200 intubation attempts were made in 150 patients. Intubation was successful in 113 (75%). A crew with paramedics was more than three times as likely to achieve successful intubation as a paramedic/emergency medical technician-Basic crew (odds ratio [OR], 3.30; P=.03). A small tube (£7.0 inches) was associated with a more than 4-fold increased likelihood of successful ETI compared with a large tube (³7.5 inches) (OR, 4.25; P=.01). After adjustment for these features, compared with little or no view of the glottis, a partial or entire view of the glottis was associated with a nearly 13-fold (OR, 12.98; P=.001) and a nearly 40-fold (OR, 39.78; Pl.001) increased likelihood of successful intubation, respectively.Conclusion: Successful ETI was more likely to be accomplished when a paramedic was partnered with another paramedic, when some or all of the glottis was visible and when a smaller endotracheal tube was used. [West J Emerg Med. 2016;17(5)640-647.]

Background The use of adequate size of blade may help minimize failures of endotracheal intubation (ETI) in non–operating room (OR) settings which are usually done by non–anesthesia health care professionals (NAHP). Prospective study was done to assess the appropriate length of the laryngoscope blade for North Indian population. Materials and Methods Upper incisor-to-vallecula (UI-V), lower incisor-to-vallecula (LI-V), and lower end of mandible to hyoid (M-H) distances were measured on routine computed tomography (CT) images of head and neck, done in the neuroradiology department in successive patients older than 11 years of age with normal airway structures. Results A total of 126 patients, which included 53 females and 73 males with an average age of 34.5 years (range 14–67 years), formed the study group. UI-V of males and females were 7.35 ± 0.54 and 6.99 ± 0.51 cm, respectively, and the difference was significant. LI-V of males and females were 7.05 ± 0.51 and 6.66 ± 0.50 cm, respectively, and the difference was significant. M-H in males and females were 3.42 ± 0.63 and 3.59 ± 0.52 cm, respectively, and the difference was not significant. Open mouth CT in 11 patients revealed an average increase of 1.66 and 0.45 cm in UI-V and LI-V ( n = 11), respectively, and 0.59 cm decrease in M-H ( n = 9) which were significant. Conclusion Upper airway dimensions of the population may be the used for selecting appropriate size of blade of laryngoscope for ETI in non-OR settings especially by NAHP.

During laryngoscopy the laryngoscope blade occasionally comes in contact with the teeth. In this case series, we described the measured force exerted on the maxillary incisors on ten patients undergoing general anesthesia requiring tracheal intubation, divided into two groups: direct laryngoscopy with Macintosh and video (McGrath) laryngoscopy. The contact force applied during laryngoscopy was measured using a pressure meter tool. This report shows that despite the prediction of uncomplicated laryngoscopy during tracheal intubation, the contact force exerted on the maxillary incisors was multifarious.

Introduction: Classical teaching in laryngoscopy advocates the use of Miller (Straight) blades to be placed underneath the epiglottis and lift it, whereas for Macintosh (Curved) blades the tip is positioned in the vallecula. Published studies in anesthesia suggest that straight blade positioning in the vallecula may be a satisfactory technique for small children. However, there is no clear evidence of consistent implementation of this methodology in practice and associated intubation success. Objectives: To assess laryngoscope blade tip position during pediatric tracheal intubation in the emergency department (ED) and its association with intubation success and time of laryngoscopy. Methods: Single center retrospective observational cohort study. Children undergoing tracheal intubation in a tertiary pediatric ED under video-recorded conditions were eligible for inclusion. A CMAC video laryngoscope was used as first line device with the video feed recorded for review. Videos were reviewed and the blade tip position during intubation recorded by study personnel. Blade tip position was categorized as ‘Correct’ if the curved blade was in the vallecula or straight blade was lifting the epiglottis; otherwise the position was categorized as ‘Incorrect’. Time of laryngoscopy was defined as time from blade insertion to removal. Univariate analysis between covariates was done by Fisher’s exact testing for intubation success and by nonparametric methods for laryngoscopy time. Results: A total of 17 complete videos were included in the study. Mac blade was used correctly in 8/10 cases (80%); Miller was used correctly in 1/7 cases (14%). Among infants (≤ 12 months), the Miller was used incorrectly in 3/4 cases (75%). Intubation was successful in 9/9 cases (100%) with correct blade position and in 5/8 cases (63%) with incorrect position (p=0.04). There was no significant difference in mean calculated laryngoscopy time for correct versus incorrect blade tip position (37.90 ± 26.80 sec vs. 44.33± 15.22 sec, p=0.12) Conclusion: Correct position of the laryngoscope blade tip is associated with higher intubation success. There was no significant difference in the laryngoscopy time for both correct and incorrect blade position.

Approach to management of anticipated difficult airway depends upon difficulty anticipated and availability of resources (expertise and instruments). Awake fibreoptic intubation is the preferred method to secure an anticipated difficult airway. However, availability of the instrument, expertise to use and patient cooperation should be considered. A conventional right handed laryngoscope blade can’t be negotiated when the airway pathology involves part or whole of the right side, compressing the airway structures towards the left. In such cases, a left-handed laryngoscope blade helps to displace the tongue and the right-sided lesion to provide an unobstructed left sided view of the larynx. Here we describe a case of difficult airway with mass in right side of the neck region with tracheal deviation to left, for which right handed conventional laryngoscope blade could not be inserted due to extension of mass up to the right side of the tongue. On the second attempt, the usual right hand laryngoscope blade was held on right hand and inserted from the left side displacing the tongue to right side and bougie held in left hand was used to guide tracheal intubation.

Objective Direct laryngoscopy can be performed using curved or straight blades, and providers usually choose the blade they are most comfortable with. However, curved blades are anecdotally thought of as easier to use than straight blades. We seek to compare intubation success rates of paramedics using curved versus straight blades. Methods Design: retrospective chart review. Setting: hospital-based suburban ALS service with 20,000 annual calls. Subjects: prehospital patients with any direct laryngoscopy intubation attempt over almost 9 years. First attempt and overall success rates were calculated for attempts with curved and straight blades. Differences between the groups were calculated. Results 2299 patients were intubated by direct laryngoscopy. 1865 had attempts with a curved blade, 367 had attempts with a straight blade, and 67 had attempts with both. Baseline characteristics were similar between groups. First attempt success was 86% with a curved blade and 73% with a straight blade: a difference of 13% (95% CI: 9–17). Overall success was 96% with a curved blade and 81% with a straight blade: a difference of 15% (95% CI: 12–18). There was an average of 1.11 intubation attempts per patient with a curved blade and 1.13 attempts per patient with a straight blade (2% difference, 95% CI: −3–7). Conclusions Our study found a significant difference in intubation success rates between laryngoscope blade types. Curved blades had higher first attempt and overall success rates when compared to straight blades. Paramedics should consider selecting a curved blade as their tool of choice to potentially improve intubation success.

Aim Neonatal intubation is a technically challenging procedure, and pressure-related injuries to surrounding structures have been reported. The primary objective of this study was to determine the pressure exerted on the upper jaw during tracheal intubation using a neonatal mannequin. Method Multidisciplinary care providers working at a neonatal intensive care unit were requested to intubate a neonatal mannequin using the standard laryngoscope and 3.0-mm (internal diameter) endotracheal tube. Compression force exerted was measured by using pressure-sensitive film taped on the upper jaw before every intubation attempt. Pressure, area under pressure and time taken to intubate were compared between the different types of health-care professionals. Results Thirty care providers intubated the mannequin three times each. Pressure impressions were observed on the developer film after every intubation attempt (n = 90). The mean pressure exerted during intubation across all health-care providers was 568 kPa (SD 78). The mean area placed under pressure was 142 mm2 (SD 45), and the mean time taken for intubation was 14.7 s (SD 4.3). There was no difference in pressure exerted on the upper jaw between frequent and less frequent intubators. It was found that pressure greater than 400 kPa was inadvertently applied on the upper jaw during neonatal intubation, far exceeding the 250 kPa shown to cause tissue injury in animal models. Conclusion The upper jaw is exposed to a significant compression force during intubation. Although such exposure is brief, it has the potential to cause tissue injury. Contact of the laryngoscope blade with the upper jaw occurred in all intubation attempts with the currently used design of laryngoscope.

Summary A bench-top study was performed to assess the effects of different laryngoscope handles on the light intensity delivered from disposable metal or plastic laryngoscope blades. The light intensity from both the handle light sources themselves and the combined handle and laryngoscope blade sets was measured using a custom-designed testing system and light meter. Five samples of each disposable blade type were tested and compared with a standard re-usable stainless steel blade using three different handle/light sources (Vital Signs LED, Heine 2.5 V Xenon and 3.5 V Xenon). The light intensity delivered by the disposable blades ranged from 790 to 3846 lux for the different handle types. Overall, the 3.5 V Heine handle delivered the highest light output (p

Visualization of the larynx by direct or indirect means is referred to as laryngoscopy and is the principal aim during airway management for passage of a tracheal tube. This paper presents a brief background regarding the development and practice of laryngoscopy and examines the equipment and techniques for both direct and indirect methods. Patient evaluation during the airway examination is discussed, as are predictors for difficult intubation. Laryngoscope blade design, newer intubating techniques, and a variety of indirect laryngoscopic technologies are reviewed, as is the learning curve for these techniques and devices.

We measured the angular change from the line of vision to the larynx around the upper incisors under defined laryngoscopic forces and investigated its association with the laryngoscopic view. Laryngoscopy was performed under general anesthesia with muscle paralysis in male patients with a difficult laryngoscopy (DLG, n = 11) and in male patients matched for age and body mass index with an easy laryngoscopy (ELG, n = 11). A Macintosh blade #3 was used for the procedure. The line of vision was marked on lateral photographs during laryngoscopy by simultaneously delineating two straight lines: a line from the upper incisors to the lowest surface of the laryngoscope blade and a line from the upper incisors to the thyroid notch. The angle difference, defined as the angle between those two lines, was measured at laryngoscopic forces of 10-50 N. The angle difference was significantly greater in the DLG than in the ELG at 50 N [median, 18.0° (range, 16.5-21.0°) vs 12.0° (12.0-13.5°), respectively; P

Intubation is a technically challenging but important skill for neonatal trainees to master. Trainees’ opportunities to perform neonatal intubation have decreased over time, due to less use of invasive ventilation, limited duty hours and changes in practice for infants born through meconium-stained fluid. Contemporary studies report suboptimal neonatal intubation success rates, ranging from 20% to 70% for paediatric residents and neonatology fellows.1 Videolaryngoscopy is a novel tool for performing, teaching and supervising intubation. Videolaryngoscopes include a camera on the laryngoscope blade which provides a wider, magnified view of the patient’s airway on a video screen. Most videolaryngoscopes, and the ones we are referring to here, can be used for either direct laryngoscopy by the intubator or indirect laryngoscopy (where the intubator uses images from the screen to perform the intubation). Both techniques allow for a supervisor to view the screen and coach the intubator during the procedure. In addition, several devices can also record videos of intubation attempts, which facilitate postintubation review and teaching. Robinson et al 2 and O’Shea et al 3 explore the use of videolaryngoscopy to define success rates and determine reasons for failure in neonatal intubations. In a randomised trial, O’Shea et al studied elective, premedicated intubations performed by …

Problem statement: Inadequate airway management is a major contributor to morbidity and mortality in the prehospital and out-of-operating room hospital settings. Difficulties that occur during airway management are usually related to the intubator not being able to achieve an adequate view of the glottic opening to allow insertion of an endotracheal tube. Approach: Obtaining an adequate glottic view is technically challenging for the experiened practioner but it is exponentially more difficult for the novice intubator. Needless to say, it is a challenge to teach the actual process of intubation using traditional direct laryngoscopy. Results: Subsequently, numerous intubation devices like the video laryngoscope have been developed that incorporate an optical fiber image transmitter integrated with a modified laryngoscope blade to facilitate visualization of the glottic opening. Conclusion: With the addition of these devices, which have a short, more beneficial learning curve, the video laryngoscope has emerged as a leading method of obtaining an improved view of the glottis opening during intubation.

Background Several studies have been published in the literature about intubation methods, but little is available on intubation equipment used in this setting. This is the first prehospital comparison of disposable plastic vs disposable stainless steel laryngoscope blades used by paramedics. Study Objective The objective of this study was to compare prehospital intubation success rates on first attempt and overall number of attempts to obtain intubations using disposable plastic laryngoscopes blades vs disposable stainless steel laryngoscope blades. Methods A retrospective prehospital cohort study was conducted during two 3-year periods. Two-way contingency table and χ2 test were conducted to determine if there was a difference between the 2 types of blades. A proportional odds model with calculated 95% confidence interval (CI) and odd ratios were then calculated. Results A total of 2472 paramedic intubations were recorded over the 6-year period. The stainless steel single-use blades had a first attempt success rate of 88.9% vs 78.5% with plastic blades (P = .01; odds ratio, 1.94; 95% CI, 1.17-3.41). The stainless steel single-use laryngoscope blade had a lower number of attempts to successful intubation than the plastic blade (88.8% vs 74.3%, respectively) (P Conclusions In the prehospital setting, stainless steel disposable blades were superior to plastic disposable blades in first attempt and overall number of attempts to intubation. Until further research is done, we recommend use of stainless steel blades for intubations in the prehospital setting by paramedics.

Summary Aim: To evaluate the new pediatric Glidescope® (Cobalt GVL® Stat) by assessing the time taken to tracheal intubation under normal and difficult intubation conditions. We hypothesized that the Glidescope® would perform as well as conventional laryngoscopy. Background: A new pediatric Glidescope® became available in October 2008. It combines a disposable, sterile laryngoscope blade and a reusable video baton. It is narrower and longer than the previous version and is available in a greater range of sizes more appropriate to pediatric use. Methods: We performed a randomized study of 32 pediatric anesthetists and intensivists to compare the Cobalt GVL® Stat with the Miller laryngoscope under simulated normal and difficult airway conditions in a pediatric manikin. Results: We found no difference in time taken to tracheal intubation using the Glidescope® or Miller laryngoscope under normal (29.3 vs 26.2 s, P = 0.36) or difficult (45.8 and 44.4 s, P = 0.84) conditions. Subjective evaluation of devices for field of view (excellent: 59% vs 53%) and ease of use (excellent: 69% vs 63%) was similar for the Miller laryngoscope and Glidescope®, respectively. However, only 34% of participants said that they would definitely use the Glidescope® in an emergency compared with 66% who would be willing to use the Miller laryngoscope. Conclusions: The new Glidescope® performs as well as the Miller laryngoscope under simulated normal and difficult airway conditions.

Summary We aimed to determine if using the EndoFlex® tracheal tube on the first intubation attempt provided improved placement times and intubation success compared with a standard-type tracheal tube in 50 patients undergoing gynaecological surgery in a prospective, randomised, cross-over trial. We found that using the EndoFlex resulted in shorter intubation times (mean (SD) 14.8 (9.7) vs 30.1 (30.5) s), easier intubation (VAS, median (range) 10 (0–70) vs 20 (0–100)), and an increased rate of successful insertion at the first attempt; all p

Background and objective: Difficult airways present a clinical challenge for anaesthetists. The Truphatek Truview EVO2© (Truphatek International Ltd, Netanya, Israel) is a new laryngoscope blade used for endotracheal intubation that could be used where there is difficulty in visualizing the laryngeal inlet. Methods: Twenty anaesthetists (12 trainees and eight consultants) compared the Truphatek Truview EVO2© with a conventional Macintosh size 3 blade. The Trucorp Airsim Bronchi© (Trucorp Ltd, Belfast, Northern Ireland, UK) manikin was intubated under normal conditions and under simulated difficult conditions such as tongue inflation and neck rigidity. In each scenario, the Cormack-Lehane grade, time needed for successful intubation, perceived difficulty of tracheal intubation and personal preference of blade were compared. The results were analysed with t-test (time of intubation), Wilcoxon signed-rank sum (Cormack-Lehane grade, ease of manoeuvre, preferred blade) and analysis of variance with Bonferroni correction (augmentation of difficulties in different scenarios). Results: The Truview EVO2 blade allowed the best laryngeal view as judged by the Cormack-Lehane grade (P < 0.05) in two separate situations: under simulated tongue inflation and under simulated neck rigidity. However, this blade did not reduce the intubation time or the ease of tracheal tube placement with respect to conventional Macintosh blade. Conclusion: Compared with the classical Macintosh blade, the Truview EVO2 blade allowed a better view of the larynx, but did not facilitate endotracheal intubation in any of the difficult scenarios created with the adjustable manikin and in most scenarios in fact prolonged the intubation time.

Background Single-use plastic blades (SUPB) and single-use metal blades (SUMB) for direct laryngoscopy and tracheal intubation have not yet been compared with reusable metal blades (RUMB) in difficult airway scenarios. Objective The purpose of our manikin study was to compare the effectiveness of these different laryngoscope blades in a difficult airway scenario, as well as in a difficult airway scenario with simulated severe inhalation injury. Methods Thirty anesthetists performed tracheal intubation (TI) with each of the three laryngoscope blades in the two scenario manikins. Results In the inhalation injury scenario, SUPB were associated with prolonged intubation times when compared with the metal blades. In the inhalation injury scenario, both metal laryngoscope blades provided a quicker, easier, and safer TI. In the difficult airway scenario, intubation times were significantly prolonged in the SUPB group in comparison to the RUMB group, but there were no significant differences between the SUPB and the SUMB. In this scenario, the RUMB demonstrated the shortest intubation times and seems to be the most effective device. Conclusions Generally, results are in line with previous studies showing significant disadvantages of SUPB in both manikin scenarios. Therefore, metal blades might be beneficial, especially in the airway management of patients with inhalation injury.

Background Plastic single-use laryngoscope blades are inexpensive and carry a lower risk of infection compared with metal reusable blades, but their efficiency during rapid sequence induction remains a matter of debate. The authors therefore compared plastic and metal blades during rapid sequence induction in a prospective randomized trial. Methods Two hundred eighty-four adult patients undergoing general anesthesia requiring rapid sequence induction were randomly assigned on a weekly basis to either plastic single-use or reusable metal blades (cluster randomization). After induction, a 60-s period was allowed to complete intubation. In the case of failed intubation, a second attempt was performed using metal blade. The primary endpoint of the study was the rate of failed intubations, and the secondary endpoint was the incidence of complications (oxygen desaturation, lung aspiration, and oropharynx trauma). Results Both groups were similar in their main characteristics, including risk factors for difficult intubation. On the first attempt, the rate of failed intubation was significantly increased in plastic blade group (17 vs. 3%; P < 0.01). In metal blade group, 50% of failed intubations were still difficult after the second attempt. In plastic blade group, all initial failed intubations were successfully intubated using metal blade, with an improvement in Cormack and Lehane grade. There was a significant increase in the complication rate in plastic group (15 vs. 6%; P < 0.05). Conclusions In rapid sequence induction of anesthesia, the plastic laryngoscope blade is less efficient than a metal blade and thus should not be recommended for use in this clinical setting.

To compare the Macintosh (M), McCoy (MC), Miller (MIL), Belscope (BP) and Lee-Fiberview (LF) laryngoscopes with respect to the grade of laryngeal visualization and the difficulty of intubation.We included 500 patients scheduled to undergo elective surgery and who required tracheal intubation. Patients were randomly assigned to five groups of 100 patients each. Anesthesia was induced intravenously using 1-3 mg.kg(-1) of propofol, fentanyl 1.5 microg.kg(-1) and atracurium 0.5 mg.kg(-1) or suxamethonium 1 mg.kg(-1). The laryngeal view was classified according to Cormack and Lehane. The degree of difficulty with intubation was rated as: Grade 1, intubation easy; Grade 2, intubation requiring an increased anterior lifting force and assistance to pull the right corner of the mouth upwards to increase space; Grade 3, intubation requiring multiple attempts and a curved stylet; Grade 4, failure to intubate with the assigned laryngoscope. Data were examined using analysis of variance, chi(2) or Fisher test, Student's t test and odds ratio. P0.05 was considered statistically significant.Laryngoscopic views obtained with the BP and MIL laryngoscopes were similar, and better than with the other types of laryngoscopes (P0.001). The levering tip of the MC blade (P = 0.02) and the fibreoptic device of the LF (P0.001) significantly improved the laryngoscopic view. Regarding the degree of difficulty with intubation, the best results were obtained with the MC and M blades (P0.001).Laryngoscopy was better with straight blades but curved blades provided better intubating conditions.

Background: The shape of a laryngoscope blade affects the exposition of the larynx. This study evaluates and compares some rigid and levering blade designs based on previous investigative X-ray laryngoscopic studies. Methods: Five rigid laryngoscope blades (Miller #3, Standard Macintosh #3, Classical Macintosh #4 and English-Macintosh #3 and #4) and two levering laryngoscope blades (McCoy in neutral and maximally elevated positions and Flexiblade in three basic positions: straight, neutral, and maximally curved) were evaluated. This study assesses two parameters derived from the depth of insertion: the eye line deviation from the ideal straight view line to the vocal cords, and the space occupied by the blade behind the mandible, which affects the contact of the blade tip with the base of the tongue. Results: The best results on larynx exposition were produced by the English-Macintosh #4 at all insertion depths between 5 and 14 cm. It surpassed the Classical Macintosh #4 and both the English and Standard Macintosh #3. Although the Miller and the Flexiblade in a straight position afford a nearly ideal view line, both blades reduce the space reserved for the tongue behind the mandible. The McCoy with its tip maximally elevated provides limited view, while activation of the Flexiblade provides various ranges of larynx exposition. Conclusion: The difference in shape and design of Macintosh blades affects their performance. The distal portion of a large-sized curved blade is more effective than the full length of a shorter blade. The #4 English Macintosh is a better choice for routine clinical use. The Flexiblade performs as a multiblade device and can therefore be used for both routine and difficult intubations.

Summary We measured the illumination generated by all 30 Macintosh size 3 laryngoscopes in our department with a lux-meter and a standardised laryngoscope holding tube. We found a large range in illumination generated (65–3130 lx). We then measured the effect on the illumination for each laryngoscope by covering the blade with a cover (LaryGard). In every case, the illumination was reduced by the LaryGard, the mean (SD) reduction was 67 (19)%. When we compared the illumination generated by a disposable laryngoscope blade with the same power source, we found that the illumination was reduced less than with the standard Macintosh covered by a LaryGard.

Airway management of children with congenital craniofacial anomalies is a challenge for paediatric anaesthesiologists. We do not have any video-assisted airway device in our department for difficult paediatric intubations. We decided to attach a regular fiberoptic (outer diameter; 3.7 mm, Karl Storz, Germany) scope to a conventional Macintosh Laryngoscope (size 1). We describe two cases of Pierre Robin and Patau's (Trisomy 13) syndrome successfully intubated with a fiberoptic-assisted laryngoscope (FOL). A fiberoptic scope and any size of a laryngoscope blade can be easily assembled in the operating room. The FOL may be a useful device in the setting of difficult paediatric intubation.

Activation of the articulating laryngoscope and external laryngeal manipulation (ELM) improve laryngeal exposure during direct laryngoscopy. We used a head-mounted direct laryngoscopy imaging system and a previously validated scoring system for assessing laryngeal view (the percentage of glottic opening or POGO score) on 33 adult patients undergoing laryngoscopy. On each patient, we videotaped the initial laryngeal exposure (blade not activated), the view with activation of the blade, and the view with operator-directed external laryngeal manipulation. The video recordings were reviewed and the laryngeal view assessed with POGO scores. POGO scores improved with blade activation in 9/33 (27%) of patients vs 28/33 (85%) of patients with ELM. In nearly half of patients studied (16/33, 48%) POGO scores decreased with blade activation. We conclude that ELM is superior to articulating laryngoscope blade activation in improving POGO scores during laryngoscopy on adult patients in standard sniffing position. Using recordings from a direct laryngoscopy video system, we compared laryngeal views in 33 patients with a special articulating laryngoscope blade to views achieved by external laryngeal manipulation (pressing on the patient’s neck). Laryngeal exposure, which is important for placement of tracheal tubes, was better with external laryngeal manipulation.

The prototypes of two novel warning devices for protection against dental trauma during direct laryngoscopy are described. Either can be attached to a standard laryngoscope blade (e.g., Macintosh). The basic design is that of as witch that is closed by pressure on the maxillary incisors by the laryngoscope blade.

Background context Irreducible anteriorly displaced odontoid fractures are usually treated with posterior atlantoaxial fusion. Purpose To present an alternative for fracture reduction and anterior stabilization for displaced odontoid fractures. Study design A technique for reduction of odontoid fractures is reported. Patient sample Case study of a single patient with an odontoid fracture. Outcome measures Only fracture reduction and fracture healing were evaluated. Methods After a failed trial of closed reduction with skeletal traction, a patient with an anteriorly displaced odontoid fracture was taken to the operating room for attempted closed reduction and odontoid screw placement. Results Fracture reduction was achieved with routine maneuvers supplemented by posterior translation through direct oropharyngeal pressure with a padded laryngoscope blade. Conclusions Direct transoral reduction of odontoid fractures is safe and feasible and can be used to assist in reduction of anteriorly displaced fractures.

OBJECTIVE: To compare intubation times and ease of use for a range of infant laryngoscope blades in the hands of accident and emergency (A&E) personnel. METHODS: Seven different blades were compared in terms of intubation times and ease of use scores in the hands of 30 A&E senior house officers (SHOs) and nurses using a standard infant manikin. RESULTS: There was a significant difference in intubation times between the seven blades (p < 0.001). Intubation with two blade designs (Seward and Soper) took almost twice as long as for the other blades (p < 0.05). Subjective ease of use scoring also identified the Seward and Soper blades as being the most difficult to use (p < 0.05). There were no significant differences between SHO and nurse intubation times or ease of use scoring. Successful intubation was achieved within 30 seconds in 90% of attempts. All but two of the subjects used an incorrect levering technique for intubation despite all having previously received training in infant intubation. CONCLUSIONS: No current standard exists regarding the utilisation of infant laryngoscope blades in the A&E department. The first line blade available should be a C shaped blade (Miller, Oxford, Robert-shaw, or Wisconsin). Other blade designs should be kept for use only by more experienced personnel or in difficult intubation situations. Intubation training must focus on correct technique and regular assessment is essential.

Endotracheal intubation of rats is a common technique that is best carried out with a laryngoscope blade. The blade allows direct visualization of the trachea during intubation, reducing the risk of accidental intubation of the esophagus. Laryngoscope blades for use in rats are not commercially available, however. Three-dimensional (3D) printers have recently become available and can be used to produce small plastic items simply and reliably based on an established design. The authors created a design for a laryngoscope blade to be printed with a 3D printer and polylactide filament material. Using the printed laryngoscope blade, the authors successfully intubated 35 rats. The presented design may be used by any experimenter with access to a 3D printer to fabricate the same laryngoscope blade for their intubation procedures.

Direct laryngoscopy (DL) has seen no substantive advances since its introduction by Janeway [1] or modifications by Miller [2] and Macintosh [3]. The difficulty in seeing around the corner beyond the tip of the laryngoscope blade has been a persistent challenge in a limited, but often unpredicted group of patients. The new possibilities offered by fiberoptics and embedded miniature video cameras may enable us to overcome many of the limitations of the direct line-of-sight.

The forces applied to the soft tissues of the upper airway may have a deleterious effect. This study was designed to evaluate the performance of the GlideScope compared with the Macintosh laryngoscope.Twenty anaesthetists and 20 trainees attempted tracheal intubation of a Laerdal SimMan manikin. Forces and pressure distribution applied by both laryngoscope blades onto the soft upper airway tissues were measured using film pressure transducers. The minimal force needed to achieve a successful intubation, in the same simulated scenario, was measured; additionally, we considered the visualization score achieved by using the Cormack-Lehane grades.All participants applied, on average, lower force with the GlideScope than with the Macintosh in each simulated scenario. Forces [mean (sd)] applied in the normal airway scenario [anaesthetists: Macintosh 39 (22) N and GlideScope 27 (15) N; trainees: Macintosh 45 (24) N and GlideScope 21 (15) N] were lower than forces applied in the difficult airway scenario [anaesthetists: Macintosh 95 (22) N and GlideScope 66 (20) N; trainees: Macintosh 100 (38) N and GlideScope 48 (16) N]. All the intubations using the GlideScope were successful, regardless of the scenario and previous intubation experience. The average pressure on the blades was 0.13 MPa for the Macintosh and 0.07 MPa for the GlideScope, showing a higher uniformity for the latter.The GlideScope allowed the participants to obtain a successful intubation applying a lower force. A flatter and more uniform pressure distribution, a higher successful rate, and a better glottic view were observed with the GlideScope.

The Truview Evo2™ laryngoscope blade is designed to improve glottic view. This study was designed to evaluate the effect of cricoid pressure (CP) on laryngeal view and the ease of orotracheal intubation with the Truview Evo2 laryngoscope.In this randomized controlled trial, 50 patients (American Society of Anesthesiologists physical status I-II, aged 18 to 60 yr) scheduled for elective surgery were enrolled. After induction of anesthesia and muscle paralysis, laryngoscopy was performed using the Truview Evo2™ laryngoscope with the patient's head in the neutral position. In Group 1, the percentage of glottic opening (POGO) score was evaluated first without CP, then with CP, and CP was applied for intubation. In Group 2, the POGO score was evaluated first with CP, then without CP, and no CP was applied for intubation. Time to intubation and number of attempts required for intubation were also recorded.In 50 patients, the mean (standard deviation) POGO view obtained with the application of CP was 93% (10%) compared with 81% (19%) in patients without CP (P0.01). Times to intubation were similar in the two groups: 14.2 (6.6) sec vs 14.0 (9.3) sec in Groups 1 and 2, respectively (P = 0.924). Sixteen percent of patients in Group 1 required a second attempt at tracheal intubation, while only 4% of patients in Group 2 required a second attempt (P = 0.162).When using the Truview Evo2™ laryngoscope with the patient's head in the neutral position, application of CP improves the glottic view. This approach is not associated with increased difficulty in intubation.

To compare the new design laryngoscope blade, Laryngopharyngeal Examination blade, with the English Macintosh blade for examination of the laryngopharynx and placement of a nasogastric tube in the presence of a tracheal tube, time taken to insert the nasogastric tube and for tracheal intubation in an adult intubation manikin.A prospective randomized and crossover trial with 81 anaesthetists of different expertise taking part in the study. Ease of laryngoscopy and tracheal intubation, examination of hypopharynx and time taken to insert the nasogastric tube were measured using the new design laryngoscope blade compared with the Macintosh blade in a manikin.Using the new design blade, examination of the hypopharynx was found easier by 75% of participants and insertion of nasogastric tube after tracheal intubation was found easier by 77% of participants. Time taken to insert the nasogastric tube was shorter with the new design blade. Ease of laryngoscopy and tracheal intubation using the new design laryngoscope blade was found to be comparable or superior to the Macintosh blade by 68% of the participants.We conclude that, in a manikin, the new design blade can make nasogastric tube insertion easier when compared with the Macintosh blade and it can be used to facilitate laryngoscopy and tracheal intubation. Further studies are needed to evaluate its use in patients.

We report a case of palatopharyngeal wall perforation during intubation with a GlideScope® laryngoscope. The likely mechanism was advancing and rotating the endotracheal tube against a taut palatopharyngeal fold. This was missed during the initial laryngoscopy, because there is a potential blind-spot in the oropharynx when attention is focused on the GlideScope® monitor. Fortunately, there were no sequelae other than minor bleeding and a mild sore throat and no surgical intervention was necessary. The use of unnecessary force during the endotracheal tube insertion, the use of too large a laryngoscope blade and the use of a rigid stylet could possibly also have been contributory factors to this complication.

Background Manual in-line stabilization (MILS) is recommended during direct laryngoscopy and intubation in patients with known or suspected cervical spine instability. Because MILS impairs glottic visualization, the authors hypothesized that anesthesiologists would apply greater pressure during intubations with MILS than without. Methods Nine anesthetized and pharmacologically paralyzed patients underwent two sequential laryngoscopies and intubations, one with MILS and one without, in random order. A transducer array along a Macintosh 3 laryngoscope blade continuously measured applied pressures, and glottic view was characterized. Results With MILS, glottic visualization was worse in six patients, and intubation failure occurred in two of these six patients. Maximum laryngoscope pressure at best glottic view was greater with MILS than without (717 +/- 339 mmHg vs. 363 +/- 121 mmHg, respectively; n = 8; P = 0.023). Other measures of pressure application also indicated comparable increases with MILS. Conclusion Pressures applied to airway tissues by the laryngoscope blade are secondarily transmitted to the cervical spine and result in cranio-cervical motion. In the presence of cervical instability, impaired glottic visualization and secondary increases in pressure application with MILS have the potential to increase pathologic cranio-cervical motion.

Background: Penile constriction devices are used for the enhancement of sexual performance. These devices have the potential to become incarcerated, leading to necrosis and amputation if not removed promptly. Objective: This article presents a step-by-step approach for the safe removal of a hardened steel penile constriction device using somewhat unorthodox tools found in a hospital. Case Report: We present a case of an incarcerated hardened steel penile constriction ring that was not able to be removed with conventional techniques. We describe a novel technique using an electric grinder and laryngoscope blade. Conclusion: The technique described in this article is a valuable and relatively safe technique for the Emergency Physician to facilitate the timely removal of a hardened steel constriction device.

Two cases are presented wherein the GlideScope videolaryngoscope (GVL) facilitated laryngeal exposure and successful endotracheal intubation, but resulted in pharyngeal injury.GlideScope videolaryngoscopy was performed in two female patients, whose airways were anticipated to present difficulties for direct laryngoscopy. In the first case, following induction of anesthesia, moderate difficulty was encountered in directing the endotracheal tube (ETT) into the patient's larynx. In the second case, minimal difficulty with the GVL was experienced, and no problems were identified with airway instrumentation until the drapes covering the patient's face were removed. In both instances, the ETT had passed through the right palatopharyngeal arch, requiring suturing in the first patient, and electrocautery in the second patient.There have been no previously published reports of injuries related to GlideScope laryngoscopy, but perforation of the palatopharyngeal arch occurring in two patients demonstrates a rare but potentially important complication of the GVL. Strategies to minimize this complication are considered.

In scenarios where difficult airway is anticipated as a result of a mass or any pathology in the right side of the upper airway, the plan of approach depends on the extent of difficulty assessed by various airway assessment tests/methods. If significant difficulty is suspected some of the available options include either an awake/sedated fibreoptic or blind nasal intubations. When the airway pathology involves part of the right side or exclusively the whole of the right side compressing the airway towards the left, there is no room to position a normal right or straight blade. A left-hand laryngoscope can be used in these types of cases where anatomy and contour of the blade manoeuvres the tongue and the right-sided lesion, thereby providing an unobstructed left-sided view of the larynx. The left-hand laryngoscope blade has been useful in converting the Cormack and Lehane grade III/IV laryngoscopies to grade II in our cases where the pathology was located exclusively on the right side of the airway. These cases suggest that there may be a role of left-hand laryngoscope in the management of difficult airway, particularly, in cases where there are right-sided mass lesions obstructing the airway.