Modified Mallampati Classification Research Articles

Predictive anatomical factors of lung aerosol deposition in obese individuals. Would modified mallampati score be relevant? Clinical trial

BackgroundObesity is a highly prevalent condition worldwide that aggravates symptoms of already existing conditions such as asthma and COPD. The limited effectiveness of inhaled medications in these individuals may be related to anatomic characteristics of their upper airways, mainly due to compressive factors. MethodsControlled clinical trial with obese and nonobese individuals. The following variables were evaluated: anthropometric characteristics, Lung and airway deposition of radiolabeled aerosol (pulmonary scintigraphy), upper airways anatomy (CT scans), and modified Mallampati score. Results29 subjects (17 nonobese and 12 obese) participated. Obese volunteers presented 30% lower aerosol lung deposition compared to nonobese. Moreover, obese subjects Mallampati classification of 4 presented an aerosol lung deposition two times lower than nonobese subjects (p = 0.021). The cross-sectional area of the retropalatal region and retroglossal region were lower in obese patients (p < 0.05), but no correlation to aerosol lung deposition was observed. BMI was associated with 32% of the variance of lung deposition (p < 0.001; β −0.28; 95% CI -0.43 to −0.11). ConclusionHigh BMI correlated to reduced percentage lung deposition. Also, modified Mallampati class 4 was even more detrimental to aerosol delivery into the lungs. Obese subjects have narrower upper airways, compared to nonobese, but this is not reflected in higher radiolabeled aerosol impaction into their oropharynx and does not predict the percentage of lung deposition in this group. Clinical trial registrationNCT03031093 (clinicaltrials.org)

Tracheal intubation using the Airtraq video laryngoscope vs. Macintosh laryngoscope in patients with anticipated difficult intubation

BackgroundVarious types of laryngoscopes have been invented to ameliorate the laryngoscopic view of the glottis, in normal and difficult airway, which helps anaesthesiologists to secure the airway during anaesthesia. In this prospective study, we aimed to compare the efficacy of the Airtraq video laryngoscope (AVL) and the Macintosh curved-blade laryngoscope (MBL), by using a common clinical assessment tool in patients with modified Mallampati class III and IV. MethodsA total of 60 patients [group A (AVL) and group M (MBL)] with modified Mallampati class III and IV listed for general anaesthesia were included. Each patient was intubated with either of the laryngoscope based on the group allotted. Time taken for tracheal intubation, grade of visualisation of glottis and need for manoeuvres to optimise the glottic view were compared. ResultsThe degree of the glottic view during successful intubation attempt was easily appreciated in group A (p < 0.0001). Difference in the requirement of manoeuvres for optimising the laryngeal view/assisting in intubation as assessed by manoeuvre score was easily appreciated in group A (p < 0.010). Rise in heart rate and mean arterial pressure 1 and 2 min after intubation was more in group M than in group A (p < 0.0001). No event of any airway trauma, as evidenced by visible trauma to lips or oral mucosa or blood on laryngoscope, was observed with either of the laryngoscope. ConclusionThe novel AVL provides better intubation conditions with greater ease of intubation, better glottic view and lesser haemodynamic alterations during laryngoscopy than MBL.

Prediction of difficult laryngoscopy in school-aged patients with microtia.

Children with microtia may experience difficult laryngoscopy because the ear and the mandible develop from the first and second bronchial arches and clefts. In this prospective observational study, we enrolled 166 patients (6-14 years old) with microtia scheduled for auricular reconstruction with autologous costal cartilage framework. Airway of the subjects was assessed preoperatively with the Modified Mallampati classification, Thyromental distance, Interincisor gap, Forward protrusion of the mandible and Horizontal length of the mandible. Anesthesiologist performed the direct laryngoscopy. Difficult laryngoscopy was classified as grade III or IV based on the Cormack-Lehane classification. A total of 166 patients completed the study, including 158 (95%) isolated microtia patients and 8 (5%) hemifacial microsomia patients. The incidence of difficult laryngoscopy was 34/166 (20.5%) in all patients, 3/8 (37.5%) in hemifacial microsomia patients, 31/158 (19.6%) in isolated microtia patients (P=0.35). Multivariate logistic regression shows that Thyromental distance, Interincisor gap, Forward protrusion of the mandible are all independent predictors of difficult laryngoscopy. The sensitivity and specificity of each predictor were: Thyromental distance (82.35%, 89.39%), Interincisor gap (58.82%, 86.36%), and Forward protrusion (17.65%, 97.73%), respectively. The cutoff values of Thyromental distance and Interincisor gap for prediction of difficult laryngoscopy were 4.0 cm and 3.3 cm. The best combination of predictors was Thyromental distance/Interincisor gap/Forward protrusion of the mandible with a sensitivity of 94.12% and specificity of 86.36%. The combination of Thyromental distance, Interincisor gap, and Forward protrusion of the mandible is the optimal assessment to predict difficult laryngoscopy in school-aged patients with microtia.

"PUSH" as a mnemonic for Modified Mallampati classification.

"PUSH" as a mnemonic for Modified Mallampati classification.

Comparative Study of Preoperative Airway Assessment by Conventional Clinical Predictors and Ultrasound-Assisted Predictors.

Aims:The aim of this study is to evaluate the effectiveness of airway sonographic parameters as the predictors of difficult laryngoscopy and to evaluate the validity of combined sonographic and clinical tests.Materials and Methods:This prospective and observational study analyzed a sample of 200 patients who were categorized as having easy (Grades 1 and 2) or difficult (Grades 3 and 4) laryngoscopy based on the laryngoscopic criteria of Cormack-Lahane (CL). Sonographic parameters, including the anterior neck soft-tissue thickness at the level of vocal cord (ANS-VC), ANS tissue thickness at the level of hyoid, and ratio of depth of pre-epiglottic space to distance from epiglottis to midpoint of the distance between vocal cords and clinical parameters, including modified Mallampati class, thyromental distance, and hyomental distance ratio (HMDR), were analyzed. Univariate and multivariate regression analysis was used for the statistical analysis.Results:Twenty patients (10%) were categorized as having difficult laryngoscopy. Statistically significant differences between patients with difficult and easy laryngoscopy were noted for 5 of 6 parameters. The diagnostic validity profiles showed variable sensitivity (26.5%–87.5%) and good specificity (58.9%–94.2%) and negative predictive value (88.8%–97.03%). ANS-VC has the highest sensitivity (87.50%) and area under curve value (0.887), whereas HMDR showed highest specificity (94.2%) and highest accuracy (89.60%) which means it has low false-positive prediction rate. The combination of tests improved the diagnostic validity profile (highest area under the curve, 0.897).Conclusion:Sonographic predictors can help in identifying difficult laryngoscopy. Combined clinical and ultrasonographic parameters showed better validity profiles in comparison to the individual tests.

The Evaluation of Upper Airway: Point of Care Ultrasound vs. Conventional Tests

Objective: The ultrasound-guided interventions have gained widespread popularity in several aspects of anesthesia practice. In this study, we aimed to compare the preoperative evaluation tests and sonographic measurements of the upper airway for the prediction of a potentially difficult airway.&#x0D; Material and Methods: In this prospective observational study, we enrolled 136 adult patients undergoing elective surgery under general anesthesia. The Modified Mallampati classification, thyromental distance, sternomental distance, and Cormack-Lehane scores were recorded. Sonographic measurements included pre-epiglottic space (PES), the distance between the midpoints of vocal cords and epiglottis (EVC). The ratio was interpreted. Main outcome is to determine the sensitivity and specificity of the upper airway ultrasound for the prediction of a potentially difficult airway.&#x0D; Results: There was no statistically significant relationship between body mass index value and thyromental distance, Thyromental/Sternomental Ratio and PES/EVC ratio, Cormack-Lehane, Mallampati classification and thyromental/sternomental distance ratio (p&gt;0.05). The sonographic measurements of airway have no significance to predict the difficult intubation and the comparison between PES, EVC and the PES/EVC ratio and assessment tests (Cormack-Lehane, Mallampati classification, thyromental and sternomental distances) was insignificant. The sternomental distance measurement was predictive for the difficult airway only in patients having body mass index more than 31.6 kg m-2.&#x0D; Conclusion: Ultrasound is a useful tool for identifying the upper airway prior to anesthesia but the validity for the prediction of difficult airway is not clear. By increasing the clinical experiences and further investigations, a greater insight into its use will be gained.

Comparison of Upper Lip Bite Test with Modified Mallampati Classification for Prediction of Difficult Endotracheal Intubation

Abstract with the full text.

Airway assessment factors as a predictive marker of difficult direct laryngoscopy: A prospective study

Background and objectives: Preoperative evaluation of anatomical landmarks help identify potentially difficult laryngoscopies; however, predictive reliability is unclear. Thus, this study was undertaken to identify and compare the most reliable variables, in prediction of difficult direct laryngoscopy. Methodology: Pre-operative assessment of ten parameters using clinical and goniometric measurement were taken and consecutively predictors of difficult intubation were identified. On the day of surgery, after premedication and induction, laryngoscopy was performed. The glottic views were graded according to the Cormack and Lehane classification. Patients of Cormack Lehane class II B and above were considered as difficult to intubate.Results: 15.4% of the cases were identified as difficult intubation. Cormack and Lehane classification had the highest diagnostic accuracy followed by Thyromental distance, sternomental distance and Modified Mallampati classification in that order. Mandibular-hyoid distance had highest sensitivity. when all ten parameters were taken into consideration, 95.7% of cases were classified correctly. Also, it classified correctly 97.7% of easy and 84.2% difficult intubation. Conclusion: Apart from Cormack-Lehane grading, upon comparison of all the parameters, a combination of Thyromental distance, Atlanto-occipital joint extension and Modified Mallampati classification were able to correctly classify 95.3% of difficult intubation.

Pre-operative voice evaluation as a hypothetical predictor of difficult laryngoscopy.

We examined the potential for voice sounds to predict a difficult airway as compared with prediction by the modified Mallampati test. A total of 453 patients scheduled for elective surgery under general anaesthesia with tracheal intubation were studied. Five phonemes were recorded and their formants analysed. Difficult laryngoscopy was defined as the Cormack-Lehane grade 3 or 4. Univariate and multivariate logistic regression were used to examine the association between some variables (mouth opening, sternomental distance, modified Mallampati and formants) and difficult laryngoscopy. Difficult laryngoscopy was reported in 29/453 (6.4%) patients. Among five regression models evaluated, the model achieving better performance to predict difficult laryngoscopy, after a variable selection criteria (stepwise, multivariate) and included a modified Mallampati classification (OR 2.920; 95%CI 1.992-4.279; p<0.001), first formant of /i/(iF1) (OR 1.003; 95%CI 1.002-1.04; p<0.001), and second formant of /i/(iF2) (OR 0.998; 95%CI 0.997-0.998; p<0.001). The receiver operating curve for a regression model that included both formants and Mallampati showed an area under curve of 0.918, higher than formants alone (area under curve 0.761) and modified Mallampati alone (area under curve 0.874). Voice presented a significant association with difficult laryngoscopy during general anaesthesia showing a 76.1% probability of correctly classifying a randomly selected patient.

Between the devil and the deep red sea: Airway trauma during introducer-guided difficult intubation

A 46-year-old woman was scheduled for total thyroidectomy and had modified Mallampati class III airway. After anaesthesia was induced, laryngoscopy revealed Cormack–Lehane grade 3a view of the vocal cords with external laryngeal manipulation. A Portex single-use tracheal tube introducer was first introduced up to 27 cm mark, after eliciting the tracheal click and hold-up signs. A Portex tracheal tube size 7 mm ID was railroaded over the introducer with some difficulty because of resistance, necessitating anticlockwise rotatory movements to slide the tube in, and the cuff was inflated. After intubation, there was a gush of blood through the tracheal tube. Correct placement was confirmed with capnography, and peak airway pressure was 32 cmH2O. Repeated suctioning was performed through the tracheal tube, and the bleeding subsided gradually. On withdrawal, the tip of the introducer was found to have blood stain. A check bronchoscopy revealed soft tissue trauma at the carina. The patient was ventilated again, and airway pressure dropped to 19 cmH2O. Her intra- and post-operative courses were uneventful. She was discharged 3 days after the operation without any further sequelae. While single-use introducers are useful in cases of difficult intubation, their use has been associated with airway trauma. We review the current use of single-use introducers and provide recommendations to minimise the associated trauma.

Neck circumference to thyromental distance ratio: Is a reliable predictor of difficult intubation in obese patients?

Neck circumference to thyromental distance ratio: Is a reliable predictor of difficult intubation in obese patients? - IJCA- Print ISSN No: - 2394-4781 Online ISSN No:- 2394-4994 Article DOI No:- 10.18231/2394-4994.2019.0029, Indian Journal of Clinical Anaesthesia-Indian J Clin Anaesth

Comparision of airway assessment by Mallampati classification and cormack and lehane grading in Indian population

Introduction: This prospective cross-sectional observational study was undertaken to compare preanaesthetic predictive value of Modified Mallampati classification in relation to Cormac Lehane grades in Indian population. Materials and Methods: One hundred patients of either sex, who have underwent general anaesthesia were includes in the study. Inclusion criteria were aged between 18 to 60 years, ASA grades I and II, weighing between 45- 80 kg. The parameters observed were, Mallampati class (MMT) during pre anaesthetic assessment and their percentages, Cormack and Lehane grades (CL) at intubation and their percentages and correlation of Cormack and Lehane grading and Mallampati classification. Results: Out of 100 patients, men women ratio was 1: 2.1(32: 68), mean age of the patients were 43.15± 12.96yrs, mean BMI of the patients were 23.34 ± 1.34 kg/m?2;. The corrected chi square test showed a value of 76.8 with a P value of Conclusion: To increase predictive value of preassessment of difficult airway, Mallampati test should be supplemented by other airway assessment tools. Keywords: Mallampati test, Predictive value, Difficult intubation.

Predictability of airway evaluation indices in diabetic and nondiabetic patients requiring general anesthesia with endotracheal intubation

Introduction: Difficult airway management (intubation and/or ventilation) results in significant morbidity and mortality. In the present study, we evaluated various clinical parameters of airway assessment and their ability to predict difficult laryngoscopy and intubation in patients with diabetes mellitus (DM) compared to nondiabetic individuals. Methods: In this prospective comparative study, we enrolled an equal number of 110 patients in DM group and non-DM group. Patients were examined for body mass index (BMI), Modified Mallampati class (MMC), mouth opening, neck extension (NE), mobility of mandible by upper lip bite test, thyromental distance (TMD), collar size, palm print sign, and prayer sign. Primary outcome measure was Cormack and Lehane's grading on direct laryngoscopy. The comparison of quantitative and qualitative variables between the groups was done using unpaired Student's “t”-test and Chi-square test, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of each test were done. Results: In DM patients, sensitivity was highest for MMC followed by prayer sign, whereas specificity was highest for palm print, followed by TMD, BMI, prayer sign, and other predictors. In non-DM individuals, sensitivity was highest for MMC whereas specificity was highest for prayer sign, followed by TMD, palm print and NE, and other predictors. Conclusions: In DM patients, sensitivity and specificity was highest for MMC and palm print, respectively. In non-DM individuals, sensitivity was highest for MMC whereas specificity was highest for prayer sign. A combination of tests may predict difficult laryngoscopy.

Correlation of anticipated difficult airway with concurrent intubation: A prospective observational study

Background: Neither all anticipated difficult airways prove to be difficult intubations nor can all difficult intubations be accurately predicted. We conducted this prospective observational study to evaluate the incidence of anticipated difficult airway and concurrent difficult intubation and look for any correlation between them. Patients and Methods: In this study, 352 patients aged >18 years posted for elective surgery requiring general anaesthesia with the placement of endotracheal tube were recruited after obtaining the Ethical Committee approval and written informed consent. The airway was examined at the time of preanaesthetic check up and assigned the modified Mallampati class and Wilson's score. The modified Mallampati Class III/IV and Wilson's score of >4 were considered a difficult airway. Concurrent intubation was graded according to the Cormack–Lehane classification on laryngoscopy. Other parameters such as the duration of laryngoscopy, time taken for intubation and number of attempts were also noted. The incidence of anticipated and unanticipated difficult airway was calculated separately for each score along with its sensitivity, specificity, positive predictive value and negative predictive value. The significance of this association was analysed using the Chi-square test. Results: The incidence of the anticipated difficult airway by the modified Mallampati classification was 6.8%, whereas that by Wilson's score was 2.5%. The incidence of actual difficult intubation was 13%. Actual difficult airways out of those anticipated by the modified Mallampati classification were only 8, whereas those anticipated by Wilson's score were 27. Correlation between them was calculated using the Chi-square test with P < 0.05 considered as statistically significant. Conclusions: Modified Mallampati classification could fairly predict the true-negative results and Wilson's score even though not routinely used is a better indicator for true-positive values. Thus, Wilson's score should be included in routine preanaesthetic evaluation.

Radiographic Predictors of Difficult Laryngoscopy in Acromegaly Patients.

Patients with acromegaly have a high risk of difficult laryngoscopy. However, clinical predictors, such as upper lip bite test or modified Mallampati class, show limited predictive performance for difficult laryngoscopy in such patients. In this retrospective study, we evaluated radiographic indices obtained from skull lateral x-ray and ostiomeatal unit computed tomography images to predict difficult laryngoscopy in acromegaly patients. Data on demographics, preoperative serum levels of pituitary hormones, and radiographic indices were collected from 90 acromegaly patients that underwent transsphenoidal removal for pituitary tumor from January 2010 to December 2016. Difficult laryngoscopy was defined as Cormack-Lehane grade ≥III. Difficult laryngoscopy occurred in 21 (23%) patients. In univariate analysis, age and radiographic indices indicating tongue size, such as tongue area (TA) on ostiomeatal unit computed tomography, linear distance from the alveolar line of the mandible to the hyoid bone, and linear distance from the interior border of the mandible to the hyoid bone on skull lateral x-ray, were associated with difficult laryngoscopy. In multivariate analysis, age (odds ratio [95% confidence interval], 1.084 [1.037-1.190]; P=0.002) and TA (1.002 [1.000-1.003], P=0.014) were independent risk factors for difficult laryngoscopy. The area under the curve of the combined model of age and TA was 0.80. Old age and radiographic predictors indicating large tongue size (large TA, long alveolar line of the mandible to the hyoid bone and mandible to the hyoid bone) were associated with an increased rate of difficult laryngoscopy in acromegaly patients. Preoperative radiographic measurements of tongue size can be helpful for safe airway management in such patients.

Correlation of Various Anthropometric and Craniofacial Variables with Severity of Obstructive sleep Apnea in Indian Population

Ethnic craniofacial morphology differences significantly affect upper airway caliber and thus apnea–hypopnea index (AHI). As there is very limited data available from India regarding factors influencing severity of obstructive sleep apnea (OSA), we tried to explore whether anthropometric and craniofacial variable predict severity of OSA. To find out correlation of simple clinical examination of craniofacial morphology and anthropometric measurements with severity of OSA in Indian population. We studied consecutive OSA patients between June 2015 and September 2016. Detailed history, physical examination (including anthropometry, clinical craniofacial assessment) and Level I polysomnography was done. Anthropometric and craniofacial parameters were correlated with AHI, nadir oxygen and percent of total time with oxygen saturation level lower than 90% during sleep (T < 90%). Out of 193 patients, 148 (76.6%) were males and 45 (23.3%) were females with ratio of 3.28:1. Mean age, mean body mass index (BMI) and mean AHI of cohort were 50.24 ± 1.65 years, 30.20 ± 0.84 kg/m2, and 53.83 ± 4.8 events per hour, respectively. With respect to AHI, nadir oxygen and T < 90%, statistically significant correlation was found for modified Mallampati class (p value = 0.001, = 0.009, = 0.002, respectively), waist circumference (p value = 0.002, < 0.001, = 0.001, respectively), neck circumference (p value < 0.001, < 0.001, < 0.001, respectively), BMI WHO cut off (p value < 0.001, < 0.001, < 0.001, respectively), and BMI Asian Indian cut off (p value = 0.001, < 0.001, < 0.001, respectively). Anthropometric and craniofacial variables are easy to perform clinical examinations. Higher modified Mallampati class, WC, NC, BMI, large tonsils and micrognathia are associated with more severe OSA.

Comparação entre o videolaringoscópio King Vision e o laringoscópio Macintosh: um ensaio clínico prospectivo randomizado e controlado

Background and objectivesWe compared the efficiency of the King Vision video laryngoscope and the Macintosh laryngoscope, when used by experienced anesthesiologists on adult patients with varying intubating conditions, in a prospective randomized controlled clinical trial. MethodsA total of 388 patients with an American Society of Anesthesiologists physical status of I or II, scheduled for general anesthesia with endotracheal intubation. Each patient was intubated with both laryngoscopes successively, in a randomized order. Intubation success rate, time to best glottic view, time to intubation, time to ventilation, Cormack–Lehane laryngoscopy grades, and complications related to the laryngoscopy and intubation were analyzed. Results and conclusionsFirst pass intubation success rates were similar for the King Vision and the Macintosh (96.6% vs. 94.3%, respectively, p>0.05). King Vision resulted in a longer average time to glottic view (95% CI 0.5–1.4s, p<0.001), and time to intubation (95% CI 3–4.6s, p<0.001). The difference in time to intubation was similar when unsuccessful intubation attempts were excluded (95% CI 2.8–4.4s, p<0.001). Based on the modified Mallampati class at the preoperative visit, the King Vision improved the glottic view in significantly more patients (220 patients, 56.7%) compared with the Macintosh (180 patients, 46.4%) (p<0.001). None of the patients had peripheral oxygen desaturation below 94%. Experienced anesthesiologists may obtain similar rates of first pass intubation success and airway trauma with both laryngoscopes. King Vision requires longer times to visualize the glottis and to intubate the trachea, but does not cause additional desaturation.

Comparison of King Vision video laryngoscope and Macintosh laryngoscope: a prospective randomized controlled clinical trial

Background and objectivesWe compared the efficiency of the King Vision video laryngoscope and the Macintosh laryngoscope, when used by experienced anesthesiologists on adult patients with varying intubating conditions, in a prospective randomized controlled clinical trial. MethodsA total of 388 patients with an American Society of Anesthesiologists physical status of I or II, scheduled for general anesthesia with endotracheal intubation. Each patient was intubated with both laryngoscopes successively, in a randomized order. Intubation success rate, time to best glottic view, time to intubation, time to ventilation, Cormack–Lehane laryngoscopy grades, and complications related to the laryngoscopy and intubation were analyzed. Results and conclusionsFirst pass intubation success rates were similar for the King Vision and the Macintosh (96.6% vs. 94.3%, respectively, p>0.05). King Vision resulted in a longer average time to glottic view (95% CI 0.5–1.4s, p<0.001), and time to intubation (95% CI 3–4.6s, p<0.001). The difference in time to intubation was similar when unsuccessful intubation attempts were excluded (95% CI 2.8–4.4s, p<0.001). Based on the modified Mallampati class at the preoperative visit, the King Vision improved the glottic view in significantly more patients (220 patients, 56.7%) compared with the Macintosh (180 patients, 46.4%) (p<0.001). None of the patients had peripheral oxygen desaturation below 94%. Experienced anesthesiologists may obtain similar rates of first pass intubation success and airway trauma with both laryngoscopes. King Vision requires longer times to visualize the glottis and to intubate the trachea, but does not cause additional desaturation.

The palatal septal cartilage implantation for snoring and obstructive sleep apnea

ObjectivePatients with snoring and obstructive sleep apnea frequently have nasal and palatal obstruction. The objective of this study was to investigate the safety and feasibility of a palatal septal cartilage implant (SCI) for snoring and obstructive sleep apnea. MethodsThis was a preliminary study of 10 consecutive patients who were enrolled retrospectively from electronic charts. The patients had undergone a single-stage operation including septoturbinoplasty and palatal SCI at a tertiary referral hospital. After nasal surgery, the harvested cartilage was prepared and trimmed into strips for palatal implantation. Key procedures of palatal SCI include vertical tunneling of the midline and paramedian soft palate, insertion of the septal cartilage strips, and fixation suture of the implants. The primary outcome measures were adverse events, including implant extrusion, infection, bleeding, velopharyngeal insufficiency and globus symptoms, assessed by the Glasgow–Edinburgh Throat Scale (GETS) questionnaire (10-item, 8-grade [0–7] Likert scale). Secondary outcomes were subjective snoring loudness (visual analogue scale, VAS), excessive daytime sleepiness (Epworth sleepiness scale, ESS) and objective apnea-hypopnea index. All patients were followed up for at least 1 year. ResultsNone of the aforementioned adverse events were noted during the one-year follow-up. Among the ten items of the GETS, the median score of nine items was 0, and the median score of the total GETS was 2.0, which was classified as “asymptomatic”. The snoring loudness improved significantly from 8.0 points (IQR 8.0–9.0) preoperation to 4.0 points (IQR 2.5–6.0) at 3 months postoperation and 4.5 points (IQR 3.3–6.0) at 1 year postoperation (P=0.002 and P=0.002, respectively). The ESS score improved significantly from 11.5 points (IQR 8.3–18.5) preoperation to 8.0 points (IQR 6.3–10.8) at 3 months postoperation and 8.5 points (IQR 6.3–10.8) at 1 year postoperation (P=0.004 and P=0.004, respectively). The apnea-hypopnea index significantly decreased from 54.7 (IQR 23.4–62.8) to 20.5 (IQR 14.7–45.6) (P=0.047) in patients with a lower tongue position (modified Mallampati class≤II; n=7). ConclusionPalatal SCI is a safe and feasible procedure. The advantages include providing implants of tailor-made length, biocompatible autologous cartilage and no need for extra-payment for the implant material. By using the SCI procedure, both nasal obstruction and sleep-disordered breathing can be managed in a single-stage operation. The long-term effectiveness of SCI deserves further research.

Cervical collar makes difficult airway: a simulation study using the LEMON criteria.

ObjectiveEndotracheal intubation is extremely difficult to perform in patients wearing a cervical collar for a head and neck injury. Therefore, we analyzed actual measurements using the look externally, evaluate 3-3-2, Mallampati score, obstruction, and neck mobility (LEMON) criteria before and after cervical collar application to investigate the causes of a difficult airway.MethodsThis simulation study was performed in 76 healthy volunteers. We measured the mouth opening, modified Mallampati classification, and neck extension before and after cervical collar application.ResultsThe mean inter-incisor distance significantly decreased from 4.3 to 2.6 cm (P<0.001). Fifty-seven participants classified as I and II were newly classified as III and IV according to the modified Mallampati classification after cervical collar application (16% to 91%). The angles of neck extension significantly decreased from 44° to 22° after cervical collar application (P<0.001). Before cervical collar application, our simulations predicted that 14 of 76 participants (18%) would have a difficult airway, whereas after cervical collar application, 76 of 76 (100%) were predicted to have a difficult airway.ConclusionAll values for the LEMON criteria (mouth opening, modified Mallampati classification, and neck extension) worsened significantly after cervical collar application. Additionally, a difficult airway was predicted in all participants after cervical collar application.