Intubation Difficulty Scale Research Articles

Intubation difficulty scale contributors and time delay in clinical practice.

The intubation difficulty scale (IDS) includes 7 contributors that provide a comprehensive assessment of difficult intubation. However, the effect of each contributor is unclear, and the scale has not been revalidated recently and has not been validated in orient. This study determined the duration of successful intubation (DSI) for each of these 7 contributors.The patients were intubated by attending anesthesiologists. The duration and other data were recorded by 2 research assistants. Anaesthesiologists reported the IDS and their perceptions. A linear mixed-effects model with a DSI was constructed using IDS factors.In total, 1095 patients were enrolled. The average DSI was 23.9 ± 21.8 seconds (37.1% IDS = 0). All 7 factors were independently associated with duration, with the exception of vocal cord adduction. The best model was as follows: DSI (in seconds) = 15.2 + 31.1 (number of additional attempts) + 26.2 (number of additional operators) + 11.4 (number of alternative techniques) + 7.9 (increased lift force) + 4.9 (external laryngeal pressure) + 3.5 (Cormack grade 1). The mixed models were similar except for the regression coefficient for the number of alternative techniques that decreased from 11.4 to 6.9 seconds.We confirmed that each IDS contributor affects the DSI and validated a prediction model with 6 IDS contributors. This prediction model may facilitate the development of strategic plans for critical airway management. Furthermore, it could improve simulations and monitor learning progress and help provide valuable feedback.

Comparison of Upper Lip Bite Test with Modified Mallampati Score in Predicting Difficult Intubation

Background and Aims: Identifying a patient with a difficult airway is important in planning anaesthetic management so that endotracheal intubation can be achieved safely. This study aims to compare modified Mallampati score with Upper Lip Bite Test to predict difficult intubation using intubation difficulty scale. Materials and methods: A prospective study was carried on 104 patients, both sexes aged between 18 to 60 years scheduled for elective surgeries under general anaesthesia fulfilling inclusion and exclusion criteria. Patient airway was evaluated by MMT and ULBT preoperatively. Predictors of difficult endotracheal intubation were assigned to MMT class III and IV, ULBT class III. After premedication and induction laryngoscopy was performed. After successful intubation Intubation difficulty score was noted down based on the sum of seven assessing parameters. A score >5 was considered difficult intubation. Results: The incidence of difficult intubation in the study was 10.6% (i.e. 11 out of 104 patients). In this study ULBT had a higher sensitivity (90.9% v/s 18.20%), specificity (95.7% v/s 75.3%) PPV (71.4% v/s 8%) and NPV (98.9% v/s 88.6%) than that of MMT Conclusion: Upper lip bite test is better at predicting difficult intubation with higher accuracy when compared to Modified Mallampati test. Both the tests are good predictors of easy intubation. Keywords: Upper Lip Bite Test (ULBT), Modified Mallampati test (MMT), Intubation Difficulty scale (IDS), airway assessment. Difficult intubation prediction, Difficult airway

Influence of videolaryngoscopy using McGrath Mac on the need for a helper to perform intubation during general anaesthesia: a multicentre randomised video-no-video trial

ObjectiveWe hypothesised that videolaryngoscopy modifies practice of tracheal intubation.DesignRandomised single-blinded study (video and no-video groups).SettingThree institutions: one academic, one non-profit and one profit.ParticipantsPatients >18 years, requiring orotracheal intubation, without predicted...

Diabetes Mellitus Olan Hastalarda C-MAC Video Laringoskop ve Macintosh Laringoskopun Elektif Trakeal Entübasyon İçin Karşılaştırılması: Randomize Kontrollü Çalışma

Objective: C-MAC video laryngoscope and Macintosh direct laryngoscope were compared in terms of intubation conditions, during elective tracheal intubation in patients with diabetes mellitus (DM) who have a high risk for difficult airway. Material and Methods: One hundred and ten American Society of Anesthesiologist physical class II-III patients with DM undergoing elective surgery were randomized to be intubated using C-MAC video laryngoscope or Macintosh laryngoscope. Glottic view Cormack Lehane (CL) score, intubation time, intubation difficulty scale (IDS) score, and first attempt intubation success were compared. Results: Similar intubation times were detected [Macintosh laryngoscope: 39.6±30.1 seconds; C-MAC: 46.7±35.4 seconds (p=0.098). C-MAC provided significantly better CL scores]. Grade 1 CL laryngeal view was observed in 37 (68%) C-MAC vs. 26 (47.3%) Macintosh laryngoscope intubations (p=0.04). An IDS score of >5 was determined in 11 (20.4%) patients with C-MAC and in 10 (18.2%) with Macintosh laryngoscope (p=0.04), indicating an overall 20.1% moderate-to-severe intubation difficulty (p=0.536). The mean IDS score was 3.2±2.9 and 2.4±3.3 with C-MAC and Macintosh laryngoscopes, (p=0.04). First-attempt intubation success was 83.3% vs. 87.0% with C-MAC vs. Macintosh laryngoscope (p=0.786). Conclusion: In patients with DM, CMAC provided improved glottis visualization, similar intubation time and first-attempt intubation success as a first-attempt intubation device compared with the Macintosh laryngoscope. However IDS scores were higher with the C-MAC. The incidence of actual intubation difficulty was found 20.1% in this diabetic study population.

Predictive Values of LEMON and LEON Scores in Elective Oral and Maxillofacial Surgery- Correlation with Intubation Difficulty Scale

Introduction: Airway management can be a major concern, due to the possibility of encountering difficult ventilation and intubation. The Modified Intubation Difficulty Scale (MIDS) is a quantitative scale that can objectively compare nasotracheal intubation. LEMON method which consists of following assessments; Look-Evaluate-Mallampati-Obstruction-Neck mobility and modified LEMON scores (LEON) are popular scoring systems described for airway management due to their easy usability. We aimed to evaluate usability of the LEMON and LEON scores in patients who underwent oral and maxillofacial surgery by studying correlation between each score and the MIDS. Materials and Methods: The records of 72 patients were reviewed retrospectively. At the pre-anesthetic evaluation; airway assessments were recorded according to LEMON, LEON scores; MIDS were recorded after intubation. Patients were allocated into two groups: Non-difficult (NonD; MIDS ≤5) and Difficult (D; MIDS >5). Correlations between scores were analyzed using Spearman’s rank correlation. Receiver operating characteristic (ROC) curve plots were used to determine possible cut-off values; specificity, sensitivity, negative-predictive values for LEON and LEMON scores. In all analyses, p<0.05 were considered statistically significant. Results: LEMON and LEON scores were correlated with the MIDS. Analysis of ROC curve plots revealed 2 cut-off values (≥4 and ≥5) for LEMON; 1 cut-off value (≥4) for LEON score. Among the scores, LEMON (≥4), LEON had the highest sensitivity and negative-predictive values (both 100%); LEON showed higher specificity than the LEMON (≥4) (96.7% vs 91.8%). LEMON (≥5) had the highest specificity (98.4%) but the lowest sensitivity (90.4%), negative-predictive value (90.9%) among the group. Conclusion: LEON scores ≥4 can be effectively used with 100% sensitivity, 96.7% specificity and, 100% negative-predictive-value for predicting difficult airway and intubation in elective maxillofacial surgeries. Keywords: Oral and maxillofacial surgery, airway assessment, LEON Score, LEMON Score, Modified Intubation Difficulty Scale

A COMPARATIVE STUDY TO ASSESS EASE OF INTUBATION WITH C-MAC VS DIRECT LARYNGOSCOPE, WHEN USED FOR INTUBATION WITH CLEAR PLASTIC DRAPES OVER MAYO STAND FOR IN COVID NEGATIVE PATIENTS DURING A PANDEMIC IN RESOURCE LIMITED SETTING

The aim of the study was to assess the time to endotracheal intubation, First-pass success when intubating with C-MAC and Direct laryngoscope with clear plastic drapes over a mayo stand. Standard anaesthesia machine and monitors Drugs for pre-medication & general anaesthesia Anatomical face masks, video laryngoscope with blades 3 & 4 Macintosh blade 3 & 4, endotracheal cuffed tubes, Bougie, Clear plastic sheets, Mayo stand. Mayo stands containment setup is suspended over the patient’s head, neck and chest. The necessary Anaesthesia equipment required for intubation will be kept inside the containment setup. General anaesthesia induced with fentanyl, Propofol & Succinylcholine. C- Mac laryngoscope with appropriate size blade will be kept with Group A patients, while Direct laryngoscope with appropriate size blade will be kept with Group B patients. The mean duration of intubation in secs was longer in Group B compared to group A ( 27.47 sec vs 21.4 sec). Based on the intubation difficulty scale score, Group B had more second attempts needed (26.67%) than Group A 6.67%) and also the second operator required in (16.67% vs 3.33%) Group B compared to Group A (p<0.05). Based on CL grades among Group B vs Group A a statistically significant association was observed in relation to grade 1 (63.33%vs93.34%), Grade2a ( 23.34% vs 3.33%) and grade 2b ( 13.33%vs3.33%). We conclude that intubation with a C-MAC laryngoscope has a better glottis view, takes a lesser duration, and lesser number of attempts required for successful intubation when compared to that of the Macintosh laryngoscopy with a plastic drape on a mayo trolley.

Comparison of McGrath Videolaryngoscope and Macintosh Laryngoscope in Children with Torticollis: Randomized Controlled Trial.

We investigated the efficacy of the McGrath videolaryngoscope compared with the Macintosh laryngoscope in children with torticollis. Thirty children aged 1–10 years who underwent surgical release of torticollis were randomly assigned into the McGrath and Macintosh groups. Orotracheal intubation was performed by a skilled anesthesiologist. The primary outcome was the intubation time. The Cormack–Lehane grade, lifting force, intubation difficulty scale (IDS), difficulty level, and intubation failure rate were also assessed. The intubation time was significantly longer in the McGrath group than in the Macintosh group (31.4 ± 6.7 s vs. 26.1 ± 5.4 s, p = 0.025). Additionally, the Cormack–Lehane grades were comparable between the groups (p = 0.101). The lifting force and IDS were significantly lower in the McGrath group than in the Macintosh group (p < 0.001 and p = 0.022, respectively). No significant differences were observed with respect to endotracheal intubation difficulty and intubation success rate. Intubation-related complications were also not observed. In conclusion, compared with the Macintosh laryngoscope, the McGrath videolaryngoscope extended the intubation time and did not improve glottic visualization in children with torticollis, despite having a lesser lifting force, lower intubation difficulty scale, and similar success rate.

Comparative Evaluation of Difficult Intubation Predictors in Children Under Two Years of Ages.

BackgroundTracheal intubation is the most reliable way of securing an airway. Pediatric airway management is one of the significant challenges, especially for non-pediatric anesthesiologists. Early airway evaluation for detecting difficult intubation and preventing catastrophic events is necessary before anesthesia, especially in children. ObjectivesTherefore, this study was done to compare some valuable adult predictors in children under two years of age.MethodsThis prospective descriptive-analytical study was performed on 405 children under two years of age that were referred for elective surgery under general anesthesia with endotracheal intubation in Imam Hossein Hospital, Isfahan. Under sedation in a supine position, we measured items, including age, weight, height, stern omental distance (SMD), mouth opening (MO), neck circumference (NC), acromio-axillo-suprasternal notch index (AASI), and intubation difficulty scale score (IDS). An expert anesthesiologist did laryngoscopy and intubation, and difficult cases were recorded.ResultsOur study showed that the frequency of difficult intubation with IDS > 4 was %16, and with IDS > 5 was %3. The variables, including age, weight, height, and SMD, significantly predicted difficult intubation. The cut-off points for age < 6 months, weight < 5/9 kg, height < 61 cm, and SMD < 5/3 cm were obtained, respectively. Other variables, such as MO, AASI, NC, and sex, were unreliable predictors for difficult intubation.ConclusionsWe found that IDS > 4, age< 6-month, weight < 5/9 kg, and SMD < 5/3 cm are predictors for difficult intubation. It is helpful for the anesthesiologist to measure these predictions before anesthesia is started to find who has difficult intubation.

Randomized, Active-Controlled, Parallel-Group Clinical Study Assessing the Efficacy and Safety of FKScope® for Nasotracheal Intubation in Patients Scheduled for Oral and Maxillofacial Surgery Under General Anesthesia.

Most of the reports showed that videolaryngoscopy has better outcomes than direct laryngoscopy for nasotracheal intubation. The FKScope® comprises a semirigid and malleable stylet with a terminal camera and has been used to facilitate orotracheal intubation. However, its efficacy and safety for nasotracheal intubation remain unknown. This study compared FKScope® with Macintosh direct laryngoscopy for nasotracheal intubation. Sixty-four patients scheduled for oral and maxillofacial surgery requiring nasotracheal intubation were enrolled and randomly assigned to FKScope® (n = 32) or Macintosh group (n = 32). The primary outcome was time to successful intubation during the first attempt. Secondary outcomes included modified nasal intubation difficulty scale (MNIDS) scores; percentage of glottic opening (POGO); immediate postintubation side effects such as mucosal bleeding, dental injury, and lip lacerations; and postoperative side effects including nasal pain, sore throat, hoarseness, dysphagia, and dyspnea. The rates of successful first-attempt intubation were 87.5% and 90.6% in the FKScope® and Macintosh group, respectively (P = 0.69). Mean (± standard deviation) total intubation time was 68.7 ± 34.8 s in the FKScope® group compared with 61.5 ± 21.9 s in the Macintosh group (P = 0.35), despite a higher POGO for the FKScope® group (77 ± 27 vs. 41 ± 31, P ＜ 0.01). The MNIDS scores of the FKScope® group were significantly lower (0.8 ± 1.0 vs. 2.8 ± 1.4, P ＜ 0.01). The groups did not differ significantly regarding most postoperative side effects, although the FKScope® group had fewer lip lacerations (P = 0.04). The use of FKScope® improves the view of the glottic opening and is safe for nasotracheal intubation with normal airways. However, secretions and blood can obstruct the camera, and therefore, to select the patient carefully is necessary.

English

BACKGROUND Endotracheal intubation for the purpose of providing anaesthesia was first described by William Mc Ewan. Jackson1 stressed the importance of anterior flexion of the lower cervical spine, in addition to obvious extension of the atlanto-occipital joint. Sniffing position has been commonly advocated as a standard head positioning for direct laryngoscopy which is achieved by flexion of the neck on chest and extension of the head at the atlanto-occipital joint. Present study was designed to evaluate the glottis view and ease of intubation achieved with direct laryngoscopy in the sniffing position with that of 25 degree backup position in a study group of 100 patients divided in 2 groups of 50 each. METHODS This study is a controlled comparative study. Controlled trial in 50 consecutive patients in each group [Group I and Group II] was conducted on patients who underwent elective surgery under general anaesthesia. Inclusion Criteria - General anaesthesia with endotracheal intubation, Aged 18 to 60 years, American society of Anaesthesiologists (ASA) grades I and II. Exclusion Criteria - Patients with body mass index more than 30 kg/m2. 1. Bucked teeth. 2. Restricted neck movement. 3. Inter-incisor gap less than 35 mm. 4. Thyro-mental distance less than 6 mm. 5. Patients with risk of regurgitation and aspiration. 6. Pharyngeal pathology. 7. Limitation of anterior and posterior movement of mandible 8. Pregnant patients Groups wereGroup I – Sniffing position Group II– 25 degree back up position RESULTS The glottis visualization was assessed by Cormack Lehane grading which revealed that glottis view was better in 25 degree backup position than sniffing position. CONCLUSIONS In our prospective randomized study in a series of 50 patients undergoing general anaesthesia in SIMS &amp; RC, intubation difficulty scale (IDS) score was better in 25 degree backup position than sniffing position. It implies glottis view is better in 25 degree backup position than sniffing position. KEYWORDS Sniffing Position, 25 Degree Backup Position, Laryngoscopy

Is there an optimal place to hold the endotracheal tube during direct laryngoscopy for patients undergoing surgery under general anesthesia? Protocol for a randomized controlled trial

BackgroundEndotracheal intubation by direct laryngoscopy is a widely performed lifesaving technique. Although there are guidelines for optimal size and depth of insertion of an endotracheal tube (ETT) for successful intubation, there is no consensus on the point at which it should be held along its length. This will arguably affect the time, ease, and success of the technique due to a difference in visualization and torque applied to the ETT after glottic visualization. We aim to compare the effect of 2 different sites of holding the ETT on time to intubation (TTI), intubation difficulty scale (IDS), and complications.MethodsASA 1–2 patients (>18 years) posted for surgery under general anesthesia, undergoing supervised intubation by anesthesia trainees (experience < 18 months), will be included. Patients with an anticipated difficult airway or unanticipated difficulty—CL grade 3 or 4 requiring the use of airway adjuncts—will be excluded. Patients will be randomized by a computer-generated number list, and allocation concealed with opaque sealed envelopes. The two sites for holding the ETT will be group 1 at 19 cm and group 2 at 24 cm. ETT marked at the selected site will be handed by the technician once the optimum position of the table, patient, and laryngoscopic view is confirmed by the intubator. The entire procedure will be video recorded. Two blinded assessors will independently review the videos to document the time to intubation and intubation difficulty score. A postoperative sore throat will be recorded.Sample sizeTo detect a 20% difference in time to intubation between groups with a significance level of 5% and power of 85%, we will need a total of 298 patients. Accounting for data loss, we plan to recruit 180 patients in each group.DiscussionThis will be the first study to assess whether the site of holding the tube has any impact on the ease and time taken for intubation. The findings of this study will provide scientific evidence for suggesting an appropriate place for holding the ETT during direct laryngoscopy procedures.Trial registrationClinical Trials Registry India CTRI/2019/09/021201

A randomized clinical trial comparing the King Vision (channeled blade) and the CMAC (D blade) videolaryngoscopes in patients with cervical spine immobilization.

Background and Aims:Cervical spine immobilization renders direct laryngoscopy difficult. The CMAC D blade and the channeled blade of the King Vision videolaryngoscopes, have both been used for difficult airway management. Our hypothesis is that the channeled blade of the King Vision would be superior to the CMAC D blade in terms of ease of intubation. We tested this hypothesis in a randomized comparison of the two videolaryngoscopes in patients with simulated cervical spine immobilization.Material and Methods:Hundred patients with no anticipated airway difficulty were randomly allocated to two groups after obtaining informed written consent. Following induction, manual inline stabilization (MILS) was applied to simulate a cervical spine injury and immobilzation. Patients were intubated with either of the two videolaryngoscopes. Time for visualization of the glottis, procedural time, intubation difficulty scale (IDS), and hemodynamic response were recorded.Results:The time to visualize the glottis was shorter in the CMAC D group as compared to the King Vision group (P < 0.001). The incidence of external laryngeal manipulation was less in the King Vision group (P < 0.001). The ease of intubation was superior in the King Vision group, based on the IDS (P < 0.001). The haemodynamic response was similar between the groups.Conclusion:King Vision channeled videolaryngoscope was difficult to introduce into the mouth of the patient during laryngoscopy. Once introduced into the mouth, the time for intubation was less and less external laryngeal manipulation maneuvers were performed to achieve successful intubation. The ease of endotracheal intubation was superior for the King Vision videolaryngoscope. The King Vision videolaryngoscope with proper tranining, could be a safe and portable alternative in patients with cervical spine immobilization.

Comparison of airway assessment tests for prediction of difficult intubation in obese patients: importance of thyromental height and upper lip bite test.

Prediction of difficult intubation (DI) has remained challenging for anesthesiologists and validity of airway assessment tests has not been fully investigated. This study aims to compare predictive values of these tests for prediction of DI in obese patients. One hundred ninety-six patients with Body Mass Index (BMI) ≥30 kg/m2 were included in this prospective study. Variables including intubation Difficulty Scale (IDS), thyromental height (TMH), hyomental distance (HMD) in extent and neutral neck position, HMD ratio (HMDR), sternomental distance (SMD), thyromental distance (TMD), ratio of height to TMD (RHTMD), width of mouth opening (MO), mandibular length (ML), Cormack-lehane (C-L) grade, upper lip bite test (ULBT), history of snoring, and obstructive sleep apnea were collected. Multiple logistic regression and receiver operating characteristic (ROC) curve analysis were used to determine independent predictors of DI (defined as IDS≥5) and their cut off points. DI and difficult laryngoscopy (defined as C-L grade ≥3) were observed in 23% and 24.5% of the study population, respectively. Multiple logistic regression identified TMH (Odds ratio (OR):0.28, 95% confidence interval (CI):0.14-0.58, P=0.001), BMI (OR:1.18, 95% CI: 1.11-1.26, P<0.001), HMDR (OR:0.45, 95% CI:0.36-0.56, P<0.001) and ULBT (OR: 3.91, 95% CI: 2.14-7.14, P<0.001) as independent predictors of DI. Sensitivity of TMH<4.8 cm, BMI>34.9 kg/m2, HMDR<1.4 and ULBT class ≥2 were determined as 75.1%, 73.3%,62.3% and 93.3% respectively. TMH and ULBT had the highest sensitivity for prediction of DI in obese patients in this study and it is recommended to be considered as part of airway assessment in this patient population.

Evaluation of thyromental height as a predictor of difficult laryngoscopy and difficult intubation: a cross-sectional observational study

Background and objectivesSeveral anthropometric measurements have been suggested to identify a potentially difficult airway. We studied thyromental height (TMH) as a predictor of difficult laryngoscopy and difficult intubation. We also compared TMH, ratio of height to thyromental distance (RHTMD), and thyromental distance (TMD) as predictors of difficult airway. MethodsThis cross-sectional observational study was conducted in 300 adult surgical patients requiring tracheal intubation. Preoperatively airway characteristics were assessed. Standard anesthesia was administered. Degree of difficulty with mask ventilation, laryngoscopic view, duration of laryngoscopy, and difficulty in tracheal intubation (intubation difficulty scale score) were noted. Multivariate logistics regression analysis was performed to identify independent predictors for difficult laryngoscopy. ResultsLaryngoscopy was difficult in 46 of 300 (15.3%) patients; all 46 patients had Cormack-Lehane grade 3 view. Duration of laryngoscopy was 27........11...s in patients with difficult laryngoscopy and 12.7........3.9...s in easy laryngoscopy; p...=...0.001. Multivariate analysis identified that TMH, presence of short neck, and history of snoring were independently associated with difficult laryngoscopy. Incidence of difficult intubation was 17.0%. A shorter TMH was associated with higher IDS scores; r...=...-0.16, p...=...0.001. TMH and duration of laryngoscopy were found to be negatively correlated; a shorter TMH was associated with a longer duration of laryngoscopy; r...=...-0.13, p...=...0.03. The cut-off threshold value for TMH in our study is 4.4 cm with a sensitivity of 66% and a specificity of 54%. ConclusionThyromental height predicts difficult laryngoscopy and difficult intubation.TMD and RHTMD did not prove to be useful as predictors of difficult airway.

Noninvasive ventilation vs. high-flow nasal cannula oxygen for preoxygenation before intubation in patients with obesity: a post hoc analysis of a randomized controlled trial

BackgroundCritically ill patients with obesity may have an increased risk of difficult intubation and subsequent severe hypoxemia. We hypothesized that pre-oxygenation with noninvasive ventilation before intubation as compared with high-flow nasal cannula oxygen may decrease the risk of severe hypoxemia in patients with obesity.MethodsPost hoc subgroup analysis of critically ill patients with obesity (body mass index ≥ 30 kg·m−2) from a multicenter randomized controlled trial comparing preoxygenation with noninvasive ventilation and high-flow nasal oxygen before intubation of patients with acute hypoxemic respiratory failure (PaO2/FiO2 < 300 mm Hg). The primary outcome was the occurrence of severe hypoxemia (pulse oximetry < 80%) during the intubation procedure.ResultsAmong the 313 patients included in the original trial, 91 (29%) had obesity with a mean body mass index of 35 ± 5 kg·m−2. Patients with obesity were more likely to experience an episode of severe hypoxemia during intubation procedure than patients without obesity: 34% (31/91) vs. 22% (49/222); difference, 12%; 95% CI 1 to 23%; P = 0.03. Among patients with obesity, 40 received preoxygenation with noninvasive ventilation and 51 with high-flow nasal oxygen. Severe hypoxemia occurred in 15 patients (37%) with noninvasive ventilation and 16 patients (31%) with high-flow nasal oxygen (difference, 6%; 95% CI − 13 to 25%; P = 0.54). The lowest pulse oximetry values during intubation procedure were 87% [interquartile range, 77–93] with noninvasive ventilation and 86% [78–92] with high-flow nasal oxygen (P = 0.98). After multivariable analysis, factors independently associated with severe hypoxemia in patients with obesity were intubation difficulty scale > 5 points and respiratory primary failure as reason for admission.ConclusionsPatients with obesity and acute hypoxemic respiratory failure had an increased risk of severe hypoxemia during intubation procedure as compared to patients without obesity. However, preoxygenation with noninvasive ventilation may not reduce this risk compared with high-flow nasal oxygen.Trial registration Clinical trial number: NCT02668458 (http://www.clinicaltrials.gov)

Dosage effect of cisatracurium on intubation and intraoperative neuromonitoring during thyroidectomy: a randomized controlled trial.

Intraoperative neuromonitoring (IONM) reduces the risk of recurrent laryngeal nerve (RLN) injury during thyroid surgery. However, the use of neuromuscular blocking agents (NMBAs), which are essential to improve intubation conditions, may hinder the electromyographic response during IONM. The aim of this prospective, double-blind, randomized controlled trial was to explore the optimal dosage of cisatracurium to produce adequate muscle relaxation for tracheal intubation without significantly affecting evoked potentials of IONM during thyroidectomy. Patients undergoing thyroidectomy with IONM in our institution, with an American Society of Anesthesiologists grade of I-II, aged 18-75 years, and with a body mass index below 32 kg/m2 were enrolled and randomly assigned (by random numbers) to receive 1× (group C1) or 2× (group C2) the effective dose (ED95) of cisatracurium for tracheal intubation. The patients, surgeons, and anesthesiologists in charge were blinded to group assignment. Anesthesia was induced with sufentanil, propofol, and cisatracurium (0.05 mg/kgin group C1, 0.1 mg/kg in group C2). Ease of intubation was evaluated with the intubation condition score (Cooper score) and the intubation difficulty scale (IDS). Amplitudes of evoked potentials during intermittent IONM were compared between groups. The primary outcomes were the Cooper score, the IDS score, and the evoked potentials of IONM. Fifty-three patients were randomized from October 2019 to November 2020, and 52 were analyzed (with 26 patients in each group). The Cooper score was significantly lower in group C1 [median, 8.0 (interquartile range, 7.0-8.3)] than in group C2 [9.0 (9.0-9.0), P<0.001]. The rate of difficult laryngoscopy without external laryngeal pressure was significantly higher in group C1 than in group C2 (61.5% vs. 11.5%, P<0.001). More patients in group C1 required assistance to complete tracheal intubation (16 vs. 4, P=0.001). The IDS score was significantly higher in group C1 [3.0 (0.0-4.0) vs. 1.0 (0.0-1.0), P=0.045]. There were no significant differences between groups in amplitudes of evoked potentials. No serious adverse events were observed. A dose of 2× ED95 of cisatracurium provided better intubation conditions and easier tracheal intubation than 1× ED95, without disturbing IONM. Chinese Clinical Trial Registry (No. ChiCTR1900022884).

A comparative evaluation of Airtraq and Hansraj Video laryngoscopes in patients undergoing tracheal intubation with cervical spine immobilization - A randomized prospective study.

Background and Aims:Airway management is a key concern in trauma patients with cervical spine fracture. Application of manual inline axial stabilization (MIAS) has become the standard of care in these patients. Indirect laryngoscopy only requires alignment of the pharyngeal and laryngeal axis. Hence the primary objective of the study was to compare two indirect laryngoscopes, Airtraq (with adaptor) and Hansraj Video laryngoscopes based on its Intubation Difficulty Score.Material and Methods:Sixty anesthetized patients were divided into two groups using computer-based randomization, and tracheal intubation was performed using either Airtraq or Hansraj Videolaryngoscope with cervical spine immobilization.Results:Both Airtraq and Hansraj groups were comparable in terms of percentage of glottic opening (POGO) scoring (92 ± 9.88% vs. 89.3 ± 10.4%.) and duration of intubation attempt (14.9 ± 4.36 sec vs. 16.97 ± 3.64 sec). Intubation difficulty scale (IDS) score was significantly shorter with Airtraq (1 ± 0.58 vs. 1.8 ± 0.805; P < 0.0001). The mean duration of time taken for laryngoscopy in Airtraq (12.9 ± 2.07 s vs. 19.06 ± 3.83 s; P < 0.0001)) was significantly shorter and also the duration of time taken to secure airway in Airtraq VL was significantly shorter (29.47 ± 4.75 s vs. 36.03 ± 5.80 sec; P < 0.0001). The heart rate and MABP changes were modest in both groups, but was significantly more in Hansraj VL as compared to Airtraq VL, post-intubation.Conclusion:Both Airtraq and Hansraj videolaryngoscope can be used as first-hand device in the scenario of cervical spine stabilization. Airtraq videolaryngoscope is better than Hansraj videolaryngoscope due to shorter IDS and lessor hemodynamic changes.

Evaluation of super-obesity and super-super-obesity as risk factors for difficult intubation in patients undergoing bariatric surgery.

Super-obesity is a serious disorder which requires bariatric surgery. The association of super-obesity and difficult intubation was not adequately established. To determine if super-obesity and super-super-obesity are associated with difficult intubation or not. University Hospital. A cohort of obese patients scheduled for bariatric surgery was prospectively recruited. Super-obesity and super-super-obesity were defined as body mass index ≥50 kg/m2 and 60 kg/m2, respectively. Intubation difficulty was assessed by 2 methods: (1) intubation difficulty scale; (2) number of intubation attempts. Risk factors for difficult intubation were recorded. Univariate and multivariate analysis for risk factors for difficult intubation and difficult mask ventilation were performed. A total of 658 patients were enrolled in the study including 205 (31%) super-obese and 52 (8%) super-super-obese patients. Ninety-nine (15%) patients required more than 1 intubation attempt, while 215 (33%) patients had intubation difficulty scale ≥5. Ninety-four (14.4%) patients had mask ventilation of moderate difficulty, while only 2 (.3%) patients needed 2-person ventilation. The independent risk factors for difficult intubation using the two stated definitions were STOP-Bang and Mallampati score values. The independent risk factors for mask ventilation of moderate difficulty were STOP-Bang score, Mallampati score, and limited neck extension. Within obese patients, neither super-obesity nor super-super-obesity was associated with difficult intubation or difficult mask ventilation. High STOP-Bang and Mallampati score are the independent factors for difficult intubation.

A randomized control led study comparing CMAC video laryngoscope and Macintosh laryngoscope for insertion of double lumen tube in patients undergoing elective thoracotomy.

Background and Aims:Double lumen tube (DLT) insertion for isolation of lung during thoracic surgery is challenging and is associated with considerable airway trauma. The advent of video laryngoscopy has revolutionized the management of difficult airway. Use of video laryngoscopy may reduce the time to intubate for DLTs even in patients with normal airway.Material and Methods:A total of 87 ASA 1–3 adults, scheduled to undergo elective thoracotomy, requiring a DLT were randomly allocated to videolaryngoscope (CMAC) arm or Macintosh laryngoscope arm. It was on open label study, and only the patient was blinded. The primary objective of this study was to compare the mean time taken for DLT intubation with CMAC (Mac 3) and Macintosh laryngoscope blade and the secondary objectives included the hemodynamic response to intubation, the level of difficulty using the intubation difficulty scale (IDS), and complications associated with intubation. Data was analysed using the statistical software SPSS (version 18.0).Results:The time taken for intubation was not significantly different (42.8 ± 14.8 s for CMAC and 42.5 ± 11.5 s for Macintosh laryngoscope P -0.908). The CMAC video laryngoscope was associated with an improved laryngoscopy grade (Grade I in 81.8% with CMAC and in 46.5% with Macintosh), less pressure applied on the tongue, and less external laryngeal pressure required. Hemodynamic responses to intubation were similar in both groups.Conclusion:Macintosh blade is as good as CMAC (mac 3) blade to facilitate DLT intubation in adult patients with no anticipated airway difficulty, however CMAC was superior as it offers better laryngoscopic view, needed less force, and fewer external laryngeal manipulations.

Betel-Nut Chewing Increases Difficulty in Tracheal Intubation.

Betel-nut chewing (BC) causes oral submucous fibrosis (OSF), and this leads to difficult tracheal intubation (DI). Unanticipated DI was reported in chewers with apparently normal preoperative airway evaluations (PAEs). This analysis aims to investigate whether BC is an independent risk on DI besides the common DI risk prediction factors. After the approval of Institutional Review Board and the written informed consent were obtained, 2,682 patients were enrolled in a cohort. PAEs, intubation difficulty scale (IDS), intubation time, and perceived DI were recorded prospectively. All 805 male patients received classical intubation, 307 with BC and 498 without BC were analyzed. Data were analyzed by Student's t-test and chi-square test. Stepwise logistic regression was performed to identify BC effects on IDS adjusting for related factors with WEKA (Waikato Environment for Knowledge Analysis; Machine Learning Group at the University of Waikato, Hamilton, New Zealand). Fewer BC patients were Cormack-Lehane (CL) grade I (38.9% vs. 47.6%) or IDS degree 〞Easy〞 (24.8% vs. 33.5%). Compared with IDS degree 〞Easy〞, patients in the BC group had a significantly higher odds ratio (OR) for 〞Slight + Moderate-Major〞 degree than in the non-BC group (adjusted OR, 1.75; 95% CI, 1.15-2.68). Compared with CL grade I, patients with BC was an independent risk for II (adjusted OR, 1.53; 95% CI, 1.02-2.32) and IV (adjusted OR, 3.25; 95% CI 1.01-10.49). Otherwise, patient's age ≥ 46 and the presence of teeth were also significant risk factors for IDS degree 〞Slight + Moderate-Major〞. BC increased not only the tracheal intubation difficulty in patients with apparent OSF but also in patients with PAEs. BC is an independent risk factor besides the commonly used DI prediction factors. We suggest physicians operating on BC patients to be better prepared for DI.