A comparative evaluation of the sniffing, the simple head extension and the head hyperextension positions for laryngoscopic view and intubation difficulty in adults undergoing direct laryngoscopy.

OBJECTIVE: This work aimed to compare between the laryngoscopy positions; sniffing, simple head extension and head hyperextension positions to assess whether the laryngeal view, intubation time and intubation difficulty could improve with one of these positions than the others. DESIGN: Prospective randomized three arms clinical trial. SETTING: Operation room, the phoniatrics unit [removed for blind peer review]. PARTICIPANTS: The study included 75 cases with 25 cases in each group. Group "A" with head in the sniffing position, Group "B" with the head in simple extension position, Group "C" with head in hyperextension position. RESULTS: The three groups were compared regarding intubation time and laryngoscopic view time. Intubation time showed statistically significant difference between the three groups. Mean of sniffing group (No. = 25) was 13.19 s (± 3.35). Mean of simple extension group (No. = 25) was 11.29 s (± 3.14). Mean of Hyperextension group (No. = 25) was 14.39 s (± 4.14). Laryngoscopic view time showed statistically highly significant difference between the three groups. Mean of sniffing group (No. = 25) was 17.19 s (± 7.27). Mean of simple group (No. = 25) was 12.18 s (± 4.46). Mean of hyperextension group (No. = 25) was 17.08 s (± 6.51). CONCLUSION: Comparing the sniffing, the simple extension and the hyperextension positions, the simple extension position showed the best time regarding intubation time and laryngoscopic view time.

Successful laryngoscope view using oversized C-Mac® D-blade in children presenting with difficult airway.

Management of the difficult paediatric airway is challenging due to anatomical differences, congenital anomalies, paucity of paediatric airway management algorithms, and the limited availability of paediatric-sized airway devices. In this case report, we describe two cases highlighting the potential use of seemingly oversized videolaryngoscopes in the management of the difficult paediatric airway. Recognising the cause of difficult airway in the paediatric population is potentially useful in the selection of a larger videolaryngoscope blade to aid laryngoscopy and intubation.

Risk factors affecting the difficulty of fiberoptic nasotracheal intubation.

BACKGROUND: The success rate of intubation under direct laryngoscopy is greatly influenced by laryngoscopic grade using the Cormack-Lehane classification. However, it is not known whether grade under direct laryngoscopy can also affects the success rate of nasotracheal intubation using a fiberoptic bronchoscpe, so this study investigated the same. In addition, we investigated other factors that influence the success rate of fiberoptic nasotracheal intubation (FNI). METHODS: FNI was performed by 18 anesthesiology residents under general anesthesia in patients over 15 years of age who underwent elective oral and maxillofacial operations. In all patients, the Mallampati grade was measured. Laryngeal view grade under direct laryngoscopy, and the degree of secretion and bleeding in the oral cavity was measured and divided into 3 grades. The time required for successful FNI was measured. If the intubation time was > 5 minutes, it was evaluated as a failure and the airway was managed by another method. The failure rate was evaluated using appropriate statistical method. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were also measured. RESULTS: A total of 650 patients were included in the study, and the failure rate of FNI was 4.5%. The patient's sex, age, height, weight, Mallampati, and laryngoscopic view grade did not affect the success rate of FNI (P > 0.05). BMI, the number of FNI performed by residents (P = 0.03), secretion (P < 0.001), and bleeding (P < 0.001) grades influenced the success rate. The AUCs of bleeding and secretion were 0.864 and 0.798, respectively, but the AUC of BMI, the number of FNI performed by residents, Mallampati, and laryngoscopic view grade were 0.527, 0.616, 0.614, and 0.544, respectively. CONCLUSION: Unlike in intubation under direct laryngoscopy, in the case of FNI, oral secretion and nasal bleeding had a significant effect on FNI difficulty than Mallampati grade or Laryngeal view grade.

The Effect of Obesity on Transnasal Flexible Laryngoscopy.

OBJECTIVE: Transnasal flexible laryngoscopy (TFL) is a practical and cost-effective procedure, allowing excellent evaluation of the upper airway with minimal risk of complications. The effect of obesity on endoscopic examination still remains unclear. The aim of this study was to determine if obesity has an effect on TFL. METHODS: Demographic data including age and gender, and physical and endoscopic examinations including body mass index (BMI), neck circumference, and grade of the laryngeal view according to Tasli classification (TC), Mallampati classification (MC), Friedman classification, and Moore tongue base classification (MTC) scores of 200 patients were evaluated. The patients were divided into two categories as obese and nonobese, and the scores of patients were compared. RESULTS: Evaluation was made of 99 (50.5%) obese and 97 (49.5%) nonobese patients ranging in age from 18 to 65 years (mean age: 37.89 ± 13.55 years). Of the 196 patients in this study, 101 (51.5%) were male, and 95 (48.5%) were female. The mean BMI of the obese and nonobese patients was 33.18 ± 5.18 (min: 25, max: 45) and 22.48 ± 1.5 (min: 19, max: 24), respectively. According to cutoff points, 27 patients (27.3%) were classified as overweight, 30 (30.3%) as obese, and 42 (42.4%) as morbidly obese. According to TC, there was no statistically significant difference between the obese and nonobese groups (mean difference 0.12, P: 0.39). In Pearson correlation analysis, the scores for a correlation between TC, and MC and MTC were 0.206 (very weak) and 0.653 (strong), respectively, which were statistically significant (P < 0.05). There was no correlation between TC and BMI values (r = -0.051; P: 0.48). CONCLUSION: The results of this study demonstrated that obesity influences the scores of MC, Friedman classification, and MTC, but does not affect the laryngeal view on TFL.

Comparison of Air-QⓇ insertion techniques in pediatric patients with fiber-optic bronchoscopic assessment: a prospective randomized control trial.

BACKGROUND: Air-QⓇ laryngeal mask airway (LMA) is a second-generation supraglottic airway device (SAD) providing adequate airway control despite the unfavorable airway anatomy in children. Several studies have assessed it as a conduit for tracheal intubation and compared its efficacy with that of other SADs, but there are no studies comparing the laryngeal view with midline and rotational insertion techniques of Air-Q. Therefore, this study compared the fiber-optic bronchoscopic (FOB) assessment of the Air-Q position using these two insertion techniques. METHODS: This randomized controlled trial included 80 patients of the American Society of Anesthesiologists physical status I/II of either sex (age group 5-12 years, weight 10-30 kg), who were scheduled for elective surgery in the supine position under general anesthesia. The patients were randomly subjected to rotational and midline technique groups (n = 40, each), and appropriate sized Air-Q, based on the weight of the patient, was inserted using the technique allocated to each patient. Time taken and number of attempts for successful insertion of the devices and any complications after removal of device were studied. RESULTS: FOB grade 1 (ideal position) was seen in 29/40 (72.5%) and 19/40 (47.5%) children subjected to the rotational and classic midline techniques, respectively (P = 0.045). The time taken to successfully insert the Air-Q was significantly lesser in the rotational technique group (7.2 ± 1.5 s) than in the classic midline technique group (10.2 ± 2.1 s) (P < 0.001), whereas complications were similar in both groups. CONCLUSIONS: The rotational technique was associated with better FOB view, and was faster than the classic midline technique of Air-Q insertion in pediatric patients.

Effect of the Macintosh curved blade size on direct laryngoscopic view in edentulous patients.

OBJECTIVE: In the present study, we compared the laryngoscopic view depending on the size of the Macintosh curved blade in edentulous patients. METHODS: Thirty-five edentulous adult patients scheduled for elective surgery were included in the study. After induction of anesthesia, two direct laryngoscopies were performed alternately using a standard-sized Macintosh curved blade (No. 4 for men and No. 3 for women) and smaller-sized Macintosh curved blade (No. 3 for men and No. 2 for women). During direct laryngoscopy with each blade, two digital photographs of the lateral view were taken when the blade tip was placed in the valleculae; the laryngoscope was lifted to achieve the best laryngeal view. Then, the best laryngeal views were assessed using the percentage of glottic opening (POGO) score. On the photographs of the lateral view of direct laryngoscopy, the angles between the line extending along the laryngoscopic handle and the horizontal line were measured. RESULTS: The POGO score was improved with the smaller-sized blade compared with the standard-sized blade (87.3% [11.8%] vs. 71.3% [20.0%], P<0.001, respectively). The angles between the laryngoscopic handle and the horizontal line were greater with the smaller-sized blade compared to the standard-sized blade when the blade tip was placed on the valleculae and when the laryngoscope was lifted to achieve the best laryngeal view (both P<0.001). CONCLUSIONS: Compared to a standard-sized Macintosh blade, a smaller-sized Macintosh curved blade improved the laryngeal exposure in edentulous patients.

Effect of Cricoid Pressure on Laryngeal View During Macintosh, McGrath MAC X-Blade and GlideScope Video Laryngoscopies.

OBJECTIVE: Cricoid pressure is useful in fasted patients requiring emergency intubation. We compared the effect of cricoid pressure on laryngeal view during Macintosh, McGrath MAC X-Blade and GlideScope video laryngoscopy. METHODS: After obtaining approval from the Human Research Ethics Committee and written informed consent from patients, we enrolled 120 patients (American Society of Anesthesiologists I-II, age 18-65 years) undergoing elective surgery that required endotracheal intubation in this prospective randomised study. Patients were divided into three groups (Macintosh, McGrath MAC X-Blade and GlideScope). RESULTS: Demographic and airway variables were similar in the groups. Cormack-Lehane grades were improved or unchanged on using cricoid pressure in Macintosh and McGrath MAC X-Blade groups. However, laryngeal views worsened in 12 patients (30%), remained unchanged in 26 patients (65%) and improved in 2 patients (5%) in the GlideScope group (p<0.001). Insertion and intubation times for Macintosh and McGrath MAC X-Blade video laryngoscopes were similar. Insertion times for GlideScope and Macintosh video laryngoscopes were similar, but were longer than those for the McGrath MAC X-Blade video laryngoscope (p=0.02). Tracheal intubation took longer with the GlideScope video laryngoscope than with the other devices (p<0.001 and p=0.003). Mean arterial pressures after insertion increased significantly in Macintosh and GlideScope groups (p=0.004 and p=0.001, respectively) compared with post-induction values. Heart rates increased after insertion in all three groups compared with post-induction values (p<0.001). Need for optimisation manoeuvres and postoperative minor complications were comparable in all three groups. CONCLUSION: Although all three devices are useful for normal or difficult intubation, cricoid pressure improved Cormack-Lehane grades of Macintosh and McGrath MAC X-Blade video laryngoscopes but statistically significantly worsened that of the GlideScope video laryngoscope.

Age and gender are important considerations in choosing the sniffing position for laryngoscopic view.

AIMS: The sniffing position is considered to be the standard position for direct laryngoscopic viewing. This crossover study evaluated age and gender as variables in comparing the benefits of the sniffing position over simple head extension for laryngeal view during direct laryngoscopy. METHODS: Laryngoscopy with a curved blade was performed on 200 anesthetized adults (100 males, 100 females) presenting for routine elective surgery. Glottic visualization was assessed by using the percentage of glottic opening (POGO) score in both simple extension and sniffing positions without the aid of the assistant or external laryngeal manipulation. Each gender group was divided into a younger group (< 50 years) and an older group (≥ 50 years). POGO scores were compared between both positions within each group. RESULTS: Mean (SD) POGO scores increased significantly only in younger male patients from 43% (39%) in the head extension position to 76% (30%) in the sniffing position. CONCLUSION: The sniffing position seems to be advantageous for getting a better laryngeal view during laryngoscopy for tracheal intubation in adult male patients less than 50 years old.

External laryngeal manipulation done by the laryngoscopist makes the best laryngeal view for intubation.

PURPOSE: External laryngeal manipulation (ELM) is used to get better laryngeal view during direct laryngoscopy. This study was designed to test the hypothesis that ELM done by the intubating anesthetist (laryngoscopist) offers the best laryngeal view for tracheal intubation. MATERIALS AND METHOD: A total of 160 patients underwent different surgical procedures were included in this study. Percentage of glottic opening (POGO) score and Cormack and Lehane scale were used as outcome measures for comparison between different laryngoscopic views. Four views were described; basic laryngoscopic view and then views after ELM done by the assistant, by the laryngoscopist and finally by the assistant after the guidance from the laryngoscopist respectively. The last three views compared with the basic laryngoscopic view. RESULTS: ELM done by the laryngoscopist or by the assistant after guidance from the laryngoscopist showed significant improvement of Cormack grades and POGO scores compared with basic laryngoscopic view. Number of patients with Cormack grade1 increased from 39 after direct laryngoscopy to 97 and 96 patients (P < 0.001 by Fisher's exact test), after ELM done by the laryngoscopist and that done by the assistant after guidance from the anesthetist respectively. Furthermore, the number of patients with POGO scores of 100% increased from 39 after direct laryngoscopy to 78 and 61 (P < 0.01) patients after ELM done by the laryngoscopist and that done by the assistant after guidance from the anesthetist respectively. CONCLUSION: It appeared from this study that ELM done by the anesthetist makes the best laryngeal view for tracheal intubation.