Mallampati Grade Research Articles

Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE): a physiological method of increasing apnoea time in patients with difficult airways.

Emergency and difficult tracheal intubations are hazardous undertakings where successive laryngoscopy–hypoxaemia–re-oxygenation cycles can escalate to airway loss and the ‘can't intubate, can't ventilate’ scenario. Between 2013 and 2014, we extended the apnoea times of 25 patients with difficult airways who were undergoing general anaesthesia for hypopharyngeal or laryngotracheal surgery. This was achieved through continuous delivery of transnasal high-flow humidified oxygen, initially to provide pre-oxygenation, and continuing as post-oxygenation during intravenous induction of anaesthesia and neuromuscular blockade until a definitive airway was secured. Apnoea time commenced at administration of neuromuscular blockade and ended with commencement of jet ventilation, positive-pressure ventilation or recommencement of spontaneous ventilation. During this time, upper airway patency was maintained with jaw-thrust. Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) was used in 15 males and 10 females. Mean (SD [range]) age at treatment was 49 (15 [25–81]) years. The median (IQR [range]) Mallampati grade was 3 (2–3 [2–4]) and direct laryngoscopy grade was 3 (3–3 [2–4]). There were 12 obese patients and nine patients were stridulous. The median (IQR [range]) apnoea time was 14 (9–19 [5–65]) min. No patient experienced arterial desaturation < 90%. Mean (SD [range]) post-apnoea end-tidal (and in four patients, arterial) carbon dioxide level was 7.8 (2.4 [4.9–15.3]) kPa. The rate of increase in end-tidal carbon dioxide was 0.15 kPa.min−1. We conclude that THRIVE combines the benefits of ‘classical’ apnoeic oxygenation with continuous positive airway pressure and gaseous exchange through flow-dependent deadspace flushing. It has the potential to transform the practice of anaesthesia by changing the nature of securing a definitive airway in emergency and difficult intubations from a pressured stop–start process to a smooth and unhurried undertaking.

Assessment of difficult airway predictors for predicting difficult laryngoscopy and intubation

Objectives: The aims and objectives of this study was to study and compare the sensitivity, specificity, positive predictive value, negative predictive value, odds ratio, relative risk, likelihood ratio and accuracy of the following parameters, modified Mallampati grading, interincisor gap, thyromental distance (TMD), ratio of height to thyromental distance (RHTMD), sternomental distance, neck movements, mandibular length and mentohyoid distance for predicting difficult laryngoscopy and/or intubation. Methods: A single blinded prospective observational study involving 100 patients of both gender between 20-70 years of age belonging to ASA physical status I, II and III scheduled to undergo elective surgery under general anaesthesia with endotracheal intubation were recruited for the study. All patients were subjected to the preoperative airway assessment and the above 8 airway parameters were recorded and analysed. The number of intubation attempts were noted. Use of intubation aids were also noted. Conclusion: Upper lip bite test can be used as a simple bedside screening test for prediction of difficult laryngoscopy/intubation but it should be combined with other airway assessment tests. RHTMD is a more accurate test than TMD. Inspite of various airway assessment tests no single test is 100% accurate. So it is advisable to use combination of different tests or the use various scoring systems for predict predicting difficult laryngoscopy/intubation.

Prediction of Difficult Endotracheal Intubation in Thyroid Surgery

Background : Thyroid surgery is usually considered as difficult airway and a risk factor for intubation. Methods : All adult patients who were undergoing thyroid surgery under general anaesthesia were prospectively included in this study over a period of eighteen months to determine the incidence of difficult intubation using the intubation difficulty scale (IDS) and to assess whether features related to goitre were associated with increased risk of difficult intubation. Depending upon the IDS score calculated, two groups were formed as Group 1→IDS ≤ 5, Group 2 → IDS > 5. The association between different variables and difficult intubation was evaluated using the chi-square test for qualitative data and the Student’s t test for quantitative data. Results : The numbers of patients in Group 1 were 156 and those in Group 2 were 31. The incidence of difficult intubation was 16.5%. The highest IDS value attained was 11. Mallampati classification III or IV, thyromental distance < 65 mm. Interincisor gap < 35 mm, neck mobility < 80 o and prognathic or retrognathic mandible were statistically significant risk factors for difficult intubation. Malignant goitre was found to be associated with difficulty in intubation. Conclusions : Except for malignant goitre no other goitre related specific risk factors were associated with increased incidence of difficult intubation. The classical risk factors for difficult intubation such as Mallampati grade III or IV, interincisor gap less than 35 mm, thyromental distance less than 65 mm, neck mobility less than 80 o and mandibular abnormality were reliable predictors.

Mucopolysaccharidosis: Otolaryngologic findings, obstructive sleep apnea and accumulation of glucosaminoglycans in lymphatic tissue of the upper airway

ObjectiveThe aim of this study is to evaluate otolaryngologic problems (upper airway obstruction, obstructive sleep apnea, restriction of mouth opening, middle ear effusion, hearing and breathing problems) and their treatments on mucopolysaccharidoses (MPS) patients and to investigate accumulation of glucosaminoglycans (GAG) in the upper airway biochemically and pathologically. Methods76 MPS patients were evaluated. Forty-two MPS patients underwent polysomnography (PSG) for obstructive sleep apnea (OSA). Pre- and postoperative PSG results of 18 patients were compared. The success and complications of treatments for OSA in MPS were evaluated. Biochemical and histopathological accumulation of GAG in tonsil and adenoid tissue and middle ear effusion were analyzed and compared with the control group. ResultsForty patients out of 42 tested with PSG had OSA (95%). Adenoid grade, Mallampati grade, restricted mouth opening, rate of difficult intubation were significantly different among MPS subtypes. MPS types III and IV had significantly lower Mallampati scores; type VI had significantly worse mouth opening; and type III had significantly better mouth opening and higher rate of easy intubation when compared to other MPS types. There was no significant difference between MPS subtypes according to tonsil grade, adenoid grade, rate of otitis media with effusion and OSA severity. Statistically significant difference was found between GAG accumulation in adenoid tissue and middle ear effusion of MPS and control group (p<0.05). However, GAG accumulation in tonsil was not significantly different between MPS and control group. There was a statistically significant improvement in postop Apnea–Hypopnea Index (AHI) compared to preop AHI (p<0.05). ConclusionsMost MPS patients have airway obstruction and OSA due to adenotonsillar hypertrophy. Most of these children benefit from adenotonsillectomy, after which OSA significantly improves. They experience high recurrence rate after adenoidectomy; though this is not clinically problematic. They also suffer from conductive hearing loss due to OME, which has to be treated with ventilation tube insertion. However, such operations are usually complicated by difficult endotracheal intubation and restricted mouth opening. Sometimes tracheotomy may be necessary. Tracheotomy is also highly complicated in MPS patients. Significant accumulation of GAG in middle ear fluid and adenoid tissue is present; however, GAG appears not to accumulate in tonsillar tissue.

Laryngeal Mask Airways and Use of a Boyle–Davis Gag in ENT Surgery

The objective was to identify whether the experience of the operating surgeon was relevant to the frequency of the laryngeal mask airway (LMA) airway obstruction or change to an endotracheal tube during ear, nose, and throat surgery. Data were prospectively collected for 186 patients undergoing a procedure with the use of a Boyle-Davis gag and LMA over 12 months in a district-general hospital in the United Kingdom. patient demographics (age, mallampati grade), grade of surgeon, grade of anesthetist, LMA size inserted, and any intraoperative adjustments needed were recorded. There was an overall intraoperative airway intervention rate of 21%. The experience of the surgeon affected the rate of intraoperative airway interventions encountered, reflected by the significantly lower rate of airway complications (ie, 10%) seen when associate specialists perform these types of procedures compared to other grades of surgeon (Fisher's exact test 2-tailed P value = .04). A significant complication rate of 50% was seen with core surgical trainees compared to other grades of surgeon (Fisher's exact test 2-tailed P value = .002). The results of this study suggest there may be a learning curve for otolaryngology trainees when using a LMA. However, larger studies and further subanalyses are essential before further conclusions can be made.

Comparison of Mallampatti Test, Thyromental Distance and Distance from Tragus to Nares for Predicting Difficult Intubation in Pediatric Patients

Clinical criteria for prediction of difficult airway in adults may not be applicable in children and available literature on the topic is limited. The objective of this prospective observational study was to assess the usefulness of Mallampati classification, thyromental distance (Tm) and distance from tragus to nares (Tn) in two groups of pediatric patients, those who are less than five and above five years of age, and to correlate these assessments with different grades of Cormack and Lehane (C&L) classification. One hundred and ninety six pediatric patients from one month to eight years of age, ASA grade I and II and planned for elective surgery under general anesthesia with tracheal intubation were recruited. Age, gender, weight (kg), BMI, distance between tragus and nares (cm), Mallampati grades and thyromental distance (cm) were noted preoperatively. Relationship of these variables with C&L grading at the time of laryngoscopy was recorded. C&L grades 2 & 3 was observed in 28 patients in younger age group (n = 120) as compared to two children above 5 years (n = 76) (p p p = 0.025) in younger age group. In conclusion, this study showed that distance between tragus to nares, Mallampati classification (if applicable) and thyromental distance can be useful for assessment of difficult airway in children less than five years of age.

Comparison of intubating conditions and haemodynamic responses during rapid tracheal intubation using either suxamethonium or rocuronium with ephedrine pretreatment

Background: Suxamethonium is considered as the “gold standard” for tracheal intubation. Because of innumerable contraindications for the use of this drug, there is a continuous search for other alternatives. Methods: In a prospective, randomized and double-blind study, we compared the intubating conditions and haemodynamic responses during rapid tracheal intubation using either suxamethonium or rocuronium with ephedrine pretreatment. We recruited 50 patients and allocated them into 2 groups (n= 25 each); Group S: received suxamethonium 1.5 mg/kg and Group R: received rocuronium 0.6 mg/ kg with ephedrine 100 μg/kg pretreatment. All patients were induced with 2 mg/kg propofol and intubation was attempted at 60 seconds. Haemodynamic responses and quality of intubating conditions were assessed. Results: Both groups were comparable in respect to age, sex, weight, Mallampati grade, Cormack Lehane grade and duration of laryngoscopy. Although both groups had clinically acceptable intubating conditions (good and excellent), there were more number of patients with better intubation score in Group S compared to Group R (p = 0.014). Conclusion: Suxamethonium still continues to be the “gold standard” for providing ideal tracheal intubation conditions. However, in conditions where suxamethonium is contraindicated, rocuronium-ephedrine combination can be used as an alternative to intubate the trachea at 60 seconds.

Palatal obturator: Perioperative concerns

Sir, A 46-year-old male, weighing 60 kg with diabetes mellitus type II since 10 years was scheduled for debridement of the nasal cavity under general anaesthesia (GA). Patient had undergone surgical procedure for mucormycosis under GA uneventfully one year ago. Systemic examination was unremarkable. The airway examination showed a Mallampati (MMP) class IV [Figure 1a] with mouth opening of 3 cm, thyromental distance of 10 cm and possible anterior mandibular protrusion. Patients blood biochemistry and other routine investigations were acceptable. Patient was kept nil per oral and premedicated with anxiolytics and antacids on the night before and on the morning of surgery while morning dose of insulin was omitted. On the day of surgery blood sugar and electrolytes were within the normal range. In the operating room, a multi parameter monitor (AS5, Datex Ohmeda, Finland) was attached to the patient and after securing intravenous (IV) access, IV glycopyrrolate 0.2 mg and IV fentanyl 120 μg were given. Difficult airway cart was kept ready. GA was induced with IV propofol 120 mg and IV succinylcholine 100 mg was given after confirmation of ability to ventilate the lungs. Oral endotracheal intubation was performed with 8.0 mm cuffed endotracheal tube with Glidescope® (GVL; Verathon Inc., Bothell, WA). During intubation, the posterior end of palatal obturator was visualized. Following correct placement of endotracheal tube, the palatal obturator was removed [Figure 1b]. Rest of the perioperative period was unremarkable.Figure 1: (a) Airway examination of patient shows a mallampati grade IV. (b) The palatal obturator after removalPalatal obturator is a prosthetic device and is indicated in patients with cleft palate, traumatic injuries and tumours of palate.[12] Palatal obturator consists of an acrylic plate and retention clasps of orthodontic wire, which covers a fistula of the palate. It serves to restore speech, mastication, deglutition and aesthetics.[12] Successful obturation depends on the volume of the defect, tissue retention available around the cavity and development of muscular control.[34] It must be as light as possible as its weight may act as a dislocating force.[3] The palatal obturator can cause anaesthetic complications including airway obstruction, inability to pass endotracheal tube due to dislodgement of prosthesis, limitation of the space for a laryngoscope and a traumatic intubation. According to recent practice guidelines for management of the difficult airway, video-assisted laryngoscopy can now be used as an initial approach to intubation in patients in non-emergent pathway with difficult airway.[5] We administered succinylcholine considering uneventful previous anaesthetic exposure of the patient and MMP class IV being the only predictor for difficult airway and rest of the airway examination also being normal.[5] The difficult airway cart with other alternative intubation devices were however kept ready. The absence of symptoms of regurgitation of food or water, MMP class IV on airway examination and observer limitation of not able to differentiate between similar looking palatal obturator with the oral mucosa in room light; all probably contributed to the cause of missed finding in the present case. However, we did not encounter any complication during the anaesthetic procedure. Pre-anaesthesia evaluation is considered as basic element of anaesthesia care and includes a multi-disciplinary approach including patient's medical record, history taking, physical examination and findings from medical tests and evaluations. At the same time, anaesthesiologist should consult other health-care professionals to obtain information relevant to perioperative care to avoid any catastrophe. Assessment performed during pre-anaesthetic evaluation may be used to formulate plans for intraoperative care, post-operative recovery, perioperative pain management and patient education.[6]

Use of the King Vision™ video laryngoscope to facilitate fibreoptic intubation in critical tracheal stenosis proves superior to the GlideScope®

To the Editor, The following describes novel airway management in a 60-yr-old female patient with inspiratory stridor, orthopnea, and dyspnea from critical tracheal stenosis. On examination, a 6 9 9 cm neck swelling extended between the cricoid cartilage and the suprasternal notch. The patient’s neck movements were normal, her mouth opening was 4 cm, and the Mallampati score was 3. Nasopharyngoscopy showed a normal glottic opening and mobile vocal cords. Computed tomography showed a large thyroid mass invading the trachea, extending beyond the suprasternal notch, and causing the trachea to deviate to the left. The intratracheal portion of the mass beginning below the cricoid cartilage extended to the first four annular cartilages, obstructing approximately 80% of the lumen so that the widest diameter in this region was 5 mm. Ultrasonography revealed a 4 9 6 cm right thyroid lobe infiltrating the trachea. The thyroid extended beyond the suprasternal notch, which precluded tracheostomy or suprasternal needle tracheotomy. In preparation for surgery, multidisciplinary discussions with the family were conducted, emphasizing the possibility of acute airway compromise following induction of anesthesia. Awake fibreoptic intubation was offered as the best option, but unfortunately the patient refused. A stepwise plan was formulated with the initial plan constituting induction of general anesthesia with fibreoptic bronchoscopy (FOB) facilitated using the GlideScope (Verathon Inc., Bothell, WA, USA). Backup plans were devised involving the King Vision video laryngoscope (King Systems, Indianapolis, IN, USA), an Eschmann tracheal tube introducer (Smiths-Medical International Ltd, Hythe, Kent, UK) (bougie), a tube exchanger, and an intubating laryngeal mask airway device (intubating LMA or ILMA), as needed. A cardiothoracic surgeon, rigid bronchoscopy, and cardiopulmonary bypass were on standby as rescue modalities. No sedative premedication was given. After applying routine monitors and with the patient in a semi-sitting position, anesthesia was induced using a target-controlled infusion of remifentanil in conjunction with 8% sevoflurane in oxygen delivered by mask ventilation. Laryngoscopy was performed using a GlideScope where a Mallampati grade 2 view was observed. A 4.5-mm flexometallic endotracheal tube (ETT) loaded on a 3.6-mm FOB was introduced to the right of the blade. Despite satisfactory visualization, it was difficult to direct the tube through the subglottic area into the trachea. The FOB was maneuvered toward the remaining patent area in the left posterior side of the subglottic area, but this abutted against the infiltrating subglottic mass, causing bleeding. The FOB and ETT were then withdrawn and bag-mask ventilation resumed. We then swapped the GlideScope for a King Vision video laryngoscope. Intubation was then successful using M. R. El-Tahan, MD (&) A. M. Khidr, MD M. AbdulShafi, MD M. S. Othman, MSc Anaesthesia and Surgical ICU, King Fahd Hospital of the University of Dammam, Al Khubar, Saudi Arabia e-mail: mohamedrefaateltahan@yahoo.com

Tracheal extubation with a laryngeal mask airway and exchange catheter in a patient with a difficult airway

To the Editor, Exchanging an endotracheal tube (ETT) for a supraglottic airway (SGA) has been described for smooth tracheal extubation and to help the patient avoid coughing at the time of emergence from anesthesia. This technique is also one of the three advanced extubation methods recommended by the Difficult Airway Society in their recent extubation guidelines. Nevertheless, there is a possibility of losing the airway during the exchange procedure. We describe a novel technique to establish a bridging SGA by utilizing an airway exchange catheter in a patient with a difficult airway. Patient consent for publication was obtained. A 38-yrold woman weighing 60 kg was scheduled for a total thyroidectomy. Her airway assessment revealed limited neck extension, receding chin, and a Mallampati grade 3 view. Direct laryngoscopy showed a grade 3 view with external laryngeal pressure, and the patient’s trachea was intubated with a 7.5-mm internal diameter ETT over an Eschmann tracheal tube introducer (gum elastic bougie). At the end of the surgery, the surgeon requested a smooth extubation with minimal cough. We planned on a bridging laryngeal mask airway (LMA) extubation technique. End-tidal sevoflurane was increased from 1 to 1.5 MAC, and 2% lidocaine 3 mL was sprayed endotracheally. The patient was maintained with positive pressure ventilation. An airway exchange catheter (19F, Cook Inc., Bloomington, IN, USA) was then inserted inside the ETT up to the 30-cm mark at the incisors and the ETT was removed. The exchange catheter was inserted into the airway tube lumen of a size-3 LMA-ProSeal (Canada Teleflex Medical, Markham, ON, Canada), and the LMA was placed into the pharynx without the metal introducer. An elbow connector with a bronchoscopy port was connected to the LMA-ProSeal with the proximal end of the exchange catheter protruding through the port (Figure). The proximal tip of the exchange catheter was occluded with tape to avoid backward air leak. The exchange catheter was removed after ensuring adequate positioning of the LMA-ProSeal by normal capnography waveform and confirming no cuff leak. The patient was then allowed to emerge from anesthesia, at which time, she could obey commands, spontaneous breathing was observed, and the LMA-ProSeal was removed without the patient coughing. If either positive pressure or spontaneous ventilation via the LMA-ProSeal had been inadequate, the ETT could have been reintroduced over the exchange catheter, followed by a conventional extubation technique. Two techniques of exchanging an ETT for a SGA at emergence have been described previously: 1) ETT removal followed by blind SGA insertion, or 2) the Bailey maneuver with insertion of a SGA behind an ETT followed by ETT removal. We consider our exchange technique to offer two potential advantages. First, because the SGA was inserted into the pharynx, over an exchange catheter, the LMA was probably positioned more precisely than with a blind insertion. Second, with the exchange catheter remaining in situ after ETT removal, reinsertion of an ETT could be readily accomplished should ventilation through the SGA fail. To perform this exchange technique, any SGA and exchange catheter or intubation introducer can be used. During this exchange process, it is essential to maintain adequate levels of anesthesia to avoid stimulation of the airway. R. Raveendran, MD S. G. Sastry, MBBS D. T. Wong, MD (&) Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada e-mail: David.Wong@uhn.ca

COMPARISON OF THE EFFICACY AND SAFETY OF EACH OF LEVITAN AND SHIKANI OPTICAL STYLETS EITHER USED ALONE OR WITH DIRECT LARYNGOSCOPY FOR TRACHEAL INTUBATION

Background: New intubating optical stylets that facilitate visualization have been developed to overcome obstacles faced with management of the difficult airway. Objective: The aim of the study was a comparison of the efficacy and safety of each of Levitan and Shikani optical stylets either used alone or with direct laryngoscopy for tracheal intubation. Methods: This study was carried out on two hundred ASA physical status I & II of both sex adult patients who were scheduled for elective surgery under general anesthesia with tracheal intubation. Patients were randomly classified according the used aid for endotracheal intubation into four equal groups (each one consisted of fifty patients). In group I (L/A), Levitan optical stylet was used alone for tracheal intubation with manual chin lift and in group II (L/L), Levitan optical stylet was used with a Macintosh laryngoscope aid to retract the base of the tongue. In group III (S/A), Shikani optical stylet was used alone and in group IV (S/L), Shikani optical stylet was used with the aid of Macintosh laryngoscope. Intubation success rate, intubation time and intubation related complications were recorded in each group. Results: Statistically, the patients of the four groups were similar in demographic data (age, sex, weight, height, mallampati grade, thyromental distance and interincisor gap). The overall intubation success rates of the four groups were statistically similar. The intubation time and the degree of difficulty in group I (L/A) were significantly lesser than in group III (S/A) and in group II (L/L) were significantly lesser than in group IV (S/L). Also the intubation time and the degree of difficulty in group II (L/L) were significantly lesser than in group I (L/A) and in group IV (S/L) were significantly lesser than in group III (S/A) (Table – 2).The incidence of the various intubation related complications are statistically similar in the four groups. In conclusion: Levitan optical stylet with or without the aid of direct laryngoscopy is more effective than Shikani optical stylet with or without the aid of direct laryngoscopy for tracheal intubation with similar incidence of intubation related complications. Key words: Levitan, Shikani, optical, stylet, intubation.

Clinical Predictors of Pediatric Obstructive Sleep Apnea/Hypopnea Syndrome

Objectives: Identify standard clinical parameters that may predict the presence and the severity of pediatric obstructive sleep apnea/hypopnea syndrome (OSAHS). Methods: Eighty-eight pediatric patients with habitual snoring who underwent a physical examination and full-night polysomnography were included in this study. Severity of nasal obstruction (NO) and mouth breathing, modified Mallampati grade (aka updated Friedman’s tongue position), tonsil size, and the body mass index (BMI) z-score in the study population were recorded. Results: When physical parameters were correlated singly with the apnea/hypopnea index (AHI), we found that gender, severity of snoring, NO, and mouth breathing status were reliable predictors of pediatric OSAHS. When all important factors were considered in a multiple stepwise regression analysis, a significant correlation with pediatric OSAHS emerged by factoring the snoring VAS, NO, and BMI z-score (Pediatric AHI = 0.108 + 0.103 Snoring VAS + 0.894 NO + 0.207 BMI z-score). Conclusions: This study has identified those findings that predict OSAHS. There is a positive correlation between snoring VAS, NO, and BMI z-score with levels of severity of OSAHS. The study can also help identify pediatric patients with habitual snoring who should be further evaluated for the presence of OSAHS.

Hypoglossal nerve conduction studies in patients with obstructive sleep apnea

EnAbstract Aim of the work To identify the correlation between obstructive sleep apnea (OSA) and motor nerve conduction study of hypoglossal nerve in terms of amplitude and terminal latency. Patients and methods The present study included 16 adult OSA patients who presented to the Otolaryngology outpatient clinic of the Suez Canal University Hospital. Exclusion criteria included previous significant facial trauma, head or neck cancer, previous surgery (including tonsillectomy or adenoidectomy), previous radiation therapy to head or neck, known diagnosis of peripheral neuropathy, any implanted device (nerve stimulator, implanted pump, pacemaker, and defibrillator), and known pregnancy. All patients were subjected to an assessment protocol that included thorough assessment of history (age, sex, snoring, nasal obstruction, and excessive daytime sleepiness), clinical examinations [BMI, apnea/hypopnea index (AHI), Friedman tongue position (FTP), and Mallampati grading], and electrophysiological studies of hypoglossal nerve. Results 87.5% of the patients had moderate to severe AHI (15 to &gt;30). The degree of excessive daytime sleepiness was slight in 18.8% of the patients, mild in 50% of the patients, and moderate in 31.3% of the patients. FTP grades ranged from grade II (FTP II) (37.5%) to grade III (FTP III) (62.5%). Mallampati grading of tonsils also ranged from grade 2 (T2) (43.8%) to grade 3 (T3) (56.2%). Seventy-five percent of the patients had delayed distal latency of hypoglossal nerve. The mean distal latency of the patients was 3.24±123 ms, with the range of 2.5–7.7 ms. All the patients had low motor amplitude of the hypoglossal nerve. There were significant positive correlations between excessive daytime sleepiness and BMI, snoring, FTP, Mallampati grading, and decreased hypoglossal nerve distal latency. Conclusion Most patients with OSA had significantly impaired hypoglossal nerve conduction in the form of delayed distal latency and low motor amplitude.

Comparison of HC video-laryngoscope versus Macintosh laryngoscope for tracheal intubation

Objective To compare HC video-laryngoscope with Macintosh laryngoscope for tracheal intubation.Methods Sixty ASA Ⅰ or Ⅱ patients of both sexes,aged 18-64 yr,with body mass index 19-27 kg/m2,Mallampati grade Ⅰ-Ⅱ,undergoing elective surgery,were randomly divided into 2 groups (n =30 each):HC video-laryngoscope group (group H) and Macintosh laryngoscope (group M).After induction of anesthesia,the patients underwent orotracheal intubation assisted by HC video-laryngoscope in group H,and by Macintosh laryngoscope in group M.The glottic exposure time,intubation time,Cormack-Lehane grade,the number of pressing the cricoid and intubation-related complications were recorded.Results The rate of satisfactory glottic exposure was significantly higher and the number of pressing the cricoid was smaller in group H than in group M (P ＜ 0.05).There was no significant difference in the glottic exposure time,intubation time and incidence of intubation-related complications between the two groups (P ＞ 0.05).Conclusion The efficacy of tracheal intubation guided by HC video-laryngoscope is better than that guided by Macintosh laryngoscope. Key words: Laryngoscopes; Intubation, intratracheal

Comparison between different tests and their combination for prediction of difficult intubation: An analytical study.

Context:There is an impelling need for accurate tests to predict difficult intubation, as failure to achieve endotracheal intubation causes significant morbidity and mortality in anesthetic practice.Aim:To calculate the validity of the different tests along with their combination and agreement when compared with endotracheal intubation in predicting difficult intubation.Settings and Design:Operation theaters, analytical study.Materials and Methods:Three hundred patients aged between 16 and 60 years of American society of anesthesiologist (ASA) physical status I and II, scheduled for elective surgical procedures requiring endotracheal intubation were studied during January-July 2012. Mallampati grade (MP), sternomental distance (SMD), thyromental distance (TMD), and Delilkan and Calder test were recorded for every patient. Endotracheal intubation was performed by an experienced anesthesiologist blinded to the measurements and recorded grading of intubation. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), likelihood ratio (LR), odds ratio (OR), and kappa coefficient of tests individually and in combination were calculated.Statistical Analysis Used:IBM SPSS software (version 16.0) and Epi-info software (version 3.2).Results:Difficult and failed intubation was 13.3% and 0.6%, respectively. Difficult intubation increased with age. TMD and Calder test showed highest sensitivity individually and Dellilkan's test showed least sensitivity. Among the combination of tests, MP with SMD and MP with Calder test had the highest sensitivity.Conclusion:Among individual test TMD and Calder are better predictive tests in terms of sensitivity. Combination of tests increases the chance of prediction of difficult intubation.

Awake intubation with video-assisted laryngoscope or intubating stylet

For anesthesiologists, it is inevitable to confront with various difficult conditions during mask ventilation and intubation. Therefore, anesthesiologists perform a variety of airway examinations and history taking to anticipate and to overcome demanding situations. Yet, the parameters obtained from such measurements are not satisfactory. In patients having the conditions that indicate difficult intubation, awake intubation is performed especially when the plausibility of mask ventilation is uncertain. Awake fiberoptic intubation has been adopted for management of anticipated difficult tracheal intubation. However, fiberoptic bronchoscope requires higher cost and longer time to learn the technique. Recently, laryngoscope or stylet with video system is used in various situations, including difficult intubation. Also, in awake intubation, some cases with video-assisted laryngoscope have been reported. Successful awake video-assisted laryngoscopic intubation has been performed in patients with limited neck extention and Mallampati grade 4 [1]. Also, Park et al. [2] reported a case of a patient with restricted mouth opening, nearly fixed neck movement and regressed mandible due to scar contracture where intubation was performed with the use of fiberoptic bronchoscopy under GlideScope® video laryngoscope guidance. Recently, Rosenstock reported that in 93 patients with an anticipated difficult intubation, there is no difference in patients' discomfort, ease of the technique and intubation success rate on the first attempt between the awake video-assisted laryngoscopic intubation and awake fiberoptic intubation [3]. Case reports with awake intubation using video-assisted intubating stylet are still rare. There is a case report that reported successful awake intubation with video-assisted intubating stylet in a patient with fixed neck due to halo vest and limited mouth opening (3 cm), in addition to modified Mallampati score grade 4 [4]. Smaller diameter of video-assisted intubating stylet can be applied to patients with more limited mouth opening or loose tooth than video-assisted laryngoscope. Video-assisted intubating stylet provided faster and easier intubations than the video-assisted laryngoscope in patients with limited neck motion [5]. In oral, laryngeal, glottic, supraglottic cancer, cancer bleeding during intubation procedure often interfere with the laryngoscopic view. In such situation, owing to smaller volume than video laryngoscope, the video-assisted intubating stylet is helpful to avoid injuring the mass and to overcome potentially traumatic airway manipulation. Patient preparation for awake intubation with video-assisted laryngoscope or intubating stylet is same as the preparation of awake fiberoptic intubation: antisialogue, oxygen supplement, topical application and transtracheal injection of local anesthetics. For adequate sedation and analgesia, combination of short acting opioids (eg. remifentanil) and sedatives (eg. propofol, or midazolam) infusion can be administered intravenously. Video-assisted laryngoscope or video-assisted stylet has an external monitor, and the supervisor can see the anatomy together and educate intubation skills on a case-by-case basis. With sufficient training of stylet usage, the quick and easy to use new instrument, such as video-assisted stylet, is expected to be selected as an alternative awake intubating device instead of the flexible fiberscope that requires longer time to learn. However, the currently used video-assisted laryngoscope and intubating stylet do not have the suction function. Therefore, preparations to prevent oral secretion are more important, and the assistant should help the oral suction of secretion or bleeding. In this respect, it is required to develop video-assisted laryngoscope or intubating stylet with the suction function in the near future.

Comparison of Laryngoscopic View and Hemodynamic Changes with Flexitip McCoy and Macintosh Laryngoscope Blade in Predicted Easy and Difficult Airway

Objective: To compare the laryngoscopic view and the hemodynamic changes by using flexitip McCoy laryngoscope with Macintosh laryngoscope. Method: Study design-Prospective randomized controlled study. A total of 220 patients were included in the study. Patients were allocated on the basis of their airway anatomy in to two groups, one is predicted easy group and the other one was predicted difficult airway group. Among each group, half of the patient intubation was performed with Macintosh blade and the other half was intubated with the help of McCoy blade. The airway prediction was done on the basis of Mallampati grade, thyromental distance, inter incisor gap, jaw protrusion and weight of the patient. Larygoscopic view and hemodynamic changes were recorded. Results: The change in pulse rate was significantly (p = 0.01) higher among the patients of Group B (85.02 ± 10.13) as compared to Group A (79.20 ± 13.11) after induction in predicted easy patients. Similar observation was found for pulse rate after laryngoscopy among both predicted easy and difficult patients. The diastolic blood pressure was significantly (p = 0.0001) higher in Group B (86.34 ± 9.78) than Group A (77.12 ± 11.66) after induction among predicted easy patients. However, diastolic blood pressure was significantly (p = 0.0004) higher in Group A (82.00 ± 10.98) compared with Group B (75.00 ± 9.06) after induction among predicted difficult patients. The average time taken during laryngoscopy was in-significantly (p > 0.05) higher in Group B (13.90 ± 5.95) compared with Group A (12.42 ± 3.58) among predicted easy patients. However, the time taken was significantly (p = 0.0001) higher in Group A (20.83 ± 2.47) than Group B (12.66 ± 3.0) in predicted difficult patients. A majority of the patients of both the groups were in Grade I (Group A = 61.8%, Group B = 81.8%) followed by Grade II (Group A = 38.2%, Group B = 18.2%) among predicted easy patients. Conclusion: It was concluded that the McCoy blade may be an answer to Macintosh blade in difficult airway cases, but not the substitute of Macintosh blade in every case. The McCoy blade improved laryngeal view in patients with limited neck extension.

Use of Laryngeal Mask Airway in the Management of a Difficult Airway: A Case Report

Background: Difficulty in management of the airway occurs most frequently in patients who have Mallampati grade III and IV, and other unfavourable airway findings like short neck, restriction in range of motion of the temporoman-dibular joints and inadequate neck flexion and extension. Because of unavailability of fibreoptic bronchoscopes or inexperience in their use, laryngeal mask airway (LMA) has become a common and acceptable airway management option. This is a case report of a postmenopausal woman who had her airway managed with LMA following initial failed intubation necessitating a rescheduling of the operation. Result: The patient had a successful surgery and postoperative recovery was uneventful. Conclusion: The LMA is a useful option in the management of an anticipated or unexpected difficult airway, especially in resource-poor settings where fibreoptic bronchoscopes may not be readily available.

Anaesthesia and orphan disease

Anaesthesia and orphan disease

Tracheal intubation with a camera embedded in the tube tip (Vivasight™)

We studied tracheal intubation in manikins and patients with a camera embedded in the tip of the tracheal tube (Vivasight(™) ). Four people in two teams and two individuals attempted intubation of a manikin through an i-gel(™) 10 times each. The tracheas of 12 patients with a Mallampati grade of 1 were intubated with a Vivasight tracheal tube through a Berman airway, passed over a Frova(™) introducer. All 60 manikin intubations were successful, taking a mean (SD) time of 1.4 (0.5)s. The fastest intubation was performed in 0.5s. All 12 participants' tracheas were successfully intubated in a median (IQR [range]) time of 90 (70-120 [50-210]) s. Seven participants complained of a sore throat, comparable with earlier findings for standard laryngoscopy and intubation: five mild; one moderate; and one severe. Tracheal intubation with the Vivasight through the i-gel or Berman airway is an alternative to existing techniques, against which it should be compared in randomised controlled trials in human participants. It has potential as a fast airway rescue technique.