Lehane Grade Research Articles

HEMODYNAMIC RESPONSES TO LARYNGOSCOPY AND INTUBATION USING MACINTOSH, MILLER AND MCCOY BLADES

Background: Direct Laryngoscopy and endotracheal intubation are essential components of administration of general anaesthesia but trigger major stress response, in the form of in­creased catecholamines leading to tachycardia and hypertension. This study is designed to compare the haemodynamic stress response with the Macintosh, McCoy and Miller blades.
 Methods: This prospective comparative study was conducted in 150 ASA grade I and II pa­tients, undergoing laparoscopic cholecystectomy under general anaesthesia from March 2017, were randomly divided into three groups using Macintosh, McCoy and Miller blade for endotracheal intubation respectively.
 Results: The groups were also comparable in respect to gender, mean age, ASA grade, Cor­mack and Lehane grade, Laryngoscopic intubation time, baseline heart rate, heart rate before laryngoscopy, baseline mean arterial pressure and Mean Arterial Pressure before laryngos­copy. The mean heart rates at end of 1, 3 and 5 minute were 93.58±13.11, 88.28±11.57 and 83.64±10.94 bpm with Macintosh blade; 93.08±12.09, 94.54±11.87 and 87.50±10.72 bpm with McCoy blades; 108.20±13.94, 95.18±12.75 and 93.22±12.32 bpm with Miller blades. Rise in heart rate as well as mean arterial pressure following intubation was greatest with Miller blade, followed by Macintosh blade and least with McCoy blade and was statistically significant (P< 0.01).
 Conclusions: Miller blade produced maximum haemodynamic stress response, followed by Macintosh blade and McCoy blade produced the least haemodynamic response, hence the latter is preferable when less haemodynamic response is desired.

Cricoid pressure during intubation: A systematic review and meta-analysis of randomised controlled trials

PurposeThis systematic review and meta-analysis aimed to determine whether cricoid pressure protects against aspiration and whether this technique adversely affects intubating conditions in adult patients. MethodsA systematic review of five databases was performed for randomised controlled trials comparing cricoid pressure to no cricoid or sham cricoid during intubation. The primary outcome was incidence of aspiration and the secondary outcomes included first attempt intubation success, time to intubation, Cormack and Lehane Grade 3 or 4 and difficult intubation. ResultsThe search identified twelve high quality RCTs with 4,862 patients for inclusion. Among four studies reporting the primary outcome, there was no difference (RR=1.18; 95%CI=0.71 to 1.96; I2=0%; p=0.51). Only 3 studies were in patients at high risk of aspiration. There was significantly worse first attempt success (RR= 0.94; 95%CI= 0.89 to 0.99; I2=66%; p=0.02), time to intubation (WMD= 6.77seconds; 95%CI=4.40 to 9.14seconds; I2=97%) and laryngoscopy views (RR=1.69; 95%CI=1.41 to 2.02;I2=1%; p<0.00001) with cricoid pressure. ConclusionsCricoid pressure failed to show any increase in protection from aspiration and may increase difficulty of intubation. Further studies in high-risk patients, such as intensive care patients, are required.

Description and comparison of the performance of the upper lip bite test, the ratio of height to thyromental distance and other methods of preoperative airway assessment in a Nigerian population – a pilot study

Background: The ability to reliably predict difficult intubation can prevent airway related adverse outcomes. The upper lip bite test (ULBT) and ratio of height to thyromental distance (RHTMD) are airway predictive tests that have been evaluated in Caucasian populations with promising results. This study determined the test performance of the ULBT and RHTMD and compared with commonly employed predictive tests (modified Mallampati [MMT], thyromental distance [TMD] and inter-incisor gap [IIG]) in adult Nigerians. Methods: This was a cross-sectional study. Two hundred and sixteen consecutive, consenting ASA I-III patients presenting for surgery and planned for general anaesthesia with endotracheal intubation over a six month period in our teaching hospital, had all five airway assessment tests (ULBT, RHTMD, MMT, TMD and IIG) assessed preoperatively. The Cormack and Lehane grading was used to determine easy or difficult visualisation of the larynx (EVL or DVL). Sensitivity, specificity, predictive values and likelihood ratios of the tests were determined. Results: The sensitivities, specificities, positive and negative predictive values and positive and negative likelihood ratios respectively for the tests were: ULBT (11.8%, 99.0%, 50.0%, 92.9%, 11.71 and 0.89), RHTMD (35.3%, 92.5%, 28.6%, 94.4%, 4.68 and 0.70), TMD (29.4%, 97.5%, 50.0%, 94.2%, 11.71 and 0.72), MMT (52.9%, 86.4%, 25.0%, 95.6%, 3.90 and 0.54), and IIG (11.8%, 97.0%, 25.0%, 92.8%, 3.90 and 0.91). Conclusion: The modified Mallampati test had the highest sensitivity in this study, however all the tests evaluated showed only low to moderate sensitivity. The ULBT and RHTMD had low sensitivities in this population. However, based on the high positive likelihood ratios of the ULBT and the TMD, whenever positive, these tests do show a high probability of DVL and these two tests would probably perform similarly in this population. Anthropometric differences may account for differences in performance of preoperative airway assessment tests in various populations.

Urgent intubation without neuromuscular blocking agents and the risk of tracheostomy.

Neuromuscular blocking agents play a significant role in improving the success rate for urgent intubation, although there is limited evidence about the effect on subsequent outcomes, such as the incidence of tracheostomy. In this retrospective cohort study, we aimed to examine the association between avoidance of neuromuscular blocking agents for urgent tracheal intubation and incidence of tracheostomy among patients in the intensive care unit (ICU). The setting of this study was an eight-bed ICU at a tertiary-care hospital in Okayama, Japan. We included patients who underwent urgent tracheal intubation at the emergency department or the ICU and were admitted to the ICU between April 2013 and November 2017. We extracted data on methods and medications of intubation, predictors for difficult intubation, Cormack–Lehane grade, patient demographics, primary diagnoses, reintubation. We estimated odds ratios and their 95% confidence intervals for elective tracheostomy during the ICU stay using logistic regression models. Of 411 patients, 46 patients underwent intubation without neuromuscular blocking agents and 61 patients underwent tracheostomy. After adjusting for potential confounders, patients who avoided neuromuscular blocking agents had more than double the odds of tracheostomy (odds ratio 2.59, 95% confidence interval 1.06–6.34, p value = 0.04). When stratifying the subjects by risk status for tracheostomy, the association was more pronounced in high-risk group, while we observed less significant association in the low-risk group. Avoidance of neuromuscular blocking agents for urgent intubation increases the risk of tracheostomy among emergency patients, especially those who have a higher risk for tracheostomy.Electronic supplementary materialThe online version of this article (10.1007/s11739-019-02214-0) contains supplementary material, which is available to authorized users.

Tracheal intubation with the McGrath MAC X-blade videolaryngoscope in morbidly obese and nonobese patients

Background/aimIncreased body mass index (BMI) and neck circumference are the two independent predictors of difficult intubation. McGrath MAC X-Blade is a videolaryngoscope specifically designed for difficult intubations.Materials and methodsEighty patients with the American Society of Anesthesiologists (ASA) physical status I–III undergoing elective surgery requiring endotracheal intubation were enrolled in the study. Patients were divided into two groups, nonobese (BMI < 30) and morbidly obese (BMI > 35). All patients were intubated with the McGrath MAC X-Blade in both groups. View optimization and tube insertion maneuvers such as reinsertion of the device, slight removal of the device, cricoid pressure, handling force, 90° anticlockwise rotation of the tube, use of stylet, and head flexion maneuvers were recorded. Cormack–Lehane grades, insertion times, intubation, and total intubation times were recorded. The hemodynamic changes and postoperative minor complications were also recorded.ResultsBody mass index, neck circumference, Mallampati scores, and ASA physical status were statistically higher in the morbidly obese group (P < 0.001 and P < 0.05). Sternomental distances were shorter in the morbidly obese (P < 0.05). Cormack–Lehane grades were comparable among the groups. The morbidly obese patients required more reinsertion attempts and cricoid pressure maneuvers during intubation than the nonobese patients (P = 0.019 versus P = 0.012, respectively). Slight removal of the device, handling force, use of the stylet, 90° anticlockwise rotation of the tube, and head flexion maneuvers were also helpful in both groups. Although device insertion times were similar between the groups, intubation and total intubation times were longer in the morbidly obese group (P = 0.009 and P = 0.034, respectively). The groups were comparable in hemodynamic changes and postoperative minor complications.ConclusionThe McGrath MAC X-Blade videolaryngoscope could safely be used both in nonobese (BMI < 30) and morbidly obese (BMI > 35) patients with the aid of some key maneuvers and with a statistically significant but clinically negligible prolongation of the intubation time.

A Study to Predict Difficult Intubation Using Simple Non-invasive test: A Prospective Observational Study

Background: Airway Management is prime importance to the anaesthesiologist of all the anaesthetic deaths 30 % to 40 % are attributed to the inability to manage a difficult airway. The various simple bedside predictors of difficult airway like Mallampati test, Upper lip bite test, Thyromental, Hyomental, Thyrosternal & Sternomental distances, mandibular length, Neck circumferences etc. are easy to perform with No extra cost or inconvenience to patients. Aim: To assess the predictability of Upper lip bite test, Hyomental distance, Thyromental distance, Thyrosternal distance & Mandibular length. Objective: 1) To find out the best predictor of difficult intubation amongst the Upper Lip Bite Test, Hyomental Distance, Thyromental Distance, Thyrosternal Distance & Mandibular Length on the basis of the test. Methods: This is a prospective observational study of 110 patients are randomly selected & age caring between 20 to 59 yrs both male and female are presented in anaesthesia of routine per anaesthetic check-up. After from mouth opening & mallampati test which are routinely done airway assessment included ULBT, HMD, TMD, TSD & ML will be done. Results: After analysing study state that the age (P = 0.031) were significant , & sex (P = 0.213) ASA (P = 0.091) were not significant with difficult intubation on the basis of Cormack lehane grading. All these factors were applicant on next set of 110 patients to found sensitivity & specificity to be ULBT ( SE = 50.00%, SP =100.00%), HMD (SE = 10.00%, SP = 97.00%), TSD (SE = 0.00%, SP = 97.00%), ML (SE = 20.00%, SP = 97.00%) & TMD (SE = 70.00%, SP = 85.00%) respectively. Conclusions: Thyromental distance is the most important sensitive factors predicting difficult intubation on the basis of cormack lehane grading in indian patients.

Effect of Head Elevation to Different Heights in Laryngeal Exposure with Direct Laryngoscopy.

The purpose of this study was to determine the optimal pillow height for the best laryngoscopic view in adult patients scheduled for elective surgery under general anaesthesia. 150 adult patients undergoing surgery under general anaesthesia with endotracheal intubation with no features suggestive of difficult airway were enrolled for the study. After induction of anaesthesia the assessment of direct laryngoscopic views was done at head positions without a pillow and with non-compressible pillows of heights 5cm and 10cm. The laryngoscopic view with the 5cm pillow was significantly superior to other head position (p<0.01). The incidence of difficult laryngoscopy (Cormack and Lehane grade III) was 32.7% without a pillow which improved to (Cormack and Lehane grade III) 4% with 10cm pillow and there were no cases of difficult laryngoscopy with 5cm pillow. The use of 5cm pillow in the 'sniffing' position obtains the best laryngoscopic view during direct laryngoscopy.

Changes in the upper airway following induction of anaesthesia: a prospective observational study protocol to determine the use of ultrasound in the assessment of a difficult airway in China

IntroductionDifficult airway management is closely related to the safety and quality of medical care. However, the low incidence of correct prediction of difficult airway in clinical screening tests presents physicians...

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.

A checklist for intrahospital transport of critically ill patients improves compliance with transportation safety guidelines

ObjectivesCritically ill patients are often transferred from the intensive care unit (ICU) to other locations around the hospital during which adverse events, some life threatening, are common. An intercollegiate guideline covering the transport of critically ill patients exists in Australasia; however, compliance with this guideline has previously been shown to be poor, and its role in improving safety in transportation of patients in the ICU is unknown. We performed a pre–post interventional study in a tertiary metropolitan ICU, assessing the impact of the introduction of a transport checklist on guideline compliance. MethodsWe performed a prospective, pre–post interventional study, including a total of 76 transfers of critically ill patients between August 2016 and April 2017. ResultsAfter introduction of the checklist, aggregate median (interquartile range) guideline compliance improved from 86.7% (80.0–92.9) to 90% (86.7–100) (p = 0.01). Significant improvements were found in notification of the transport destination (83.7% vs 100%, p = 0.010) and transporting doctors' knowledge of the Cormack–Lehane grade of laryngoscopy (60.5% vs. 84.2%, p = 0.021). There was, however, a reduction in the proportion of full oxygen cylinders taken on transports (100% vs. 76.3%, p = 0.002). ConclusionsWe conclude that a checklist is useful in improving safety in the transport of a critically ill patient population.

Retrospective audit of airway management practices in children with craniocervical pathology.

Craniocervical immobilization using halo body orthoses may be required in the management of children with craniocervical junction pathology. To date, the effect of such immobilization on perioperative anesthetic management has not been addressed in large series. The aim of this study was to review the airway management of children requiring halo body orthoses undergoing general anesthesia. The study was a retrospective case note review from a single institution. The neurosurgical database was interrogated to identify all patients less than 16years of age that required a halo body orthosis from 1996 to 2015. We used the electronic patient record to identify all procedures performed under general anesthesia for these patients, either for halo application, or with the halo in situ. Details of techniques used for airway management were recorded, and paired data between individuals pre- and post-halo application were compared. Demographic data, diagnosis, and perioperative complications were also recorded. We identified 90 children that underwent placement of a halo body orthosis. A total of 269 anesthetic records from these patients were analyzed and classified as pre-halo application, or halo in situ. Facemask ventilation was achieved in all patients, though some required simple airway adjuncts and may have been more difficult in the presence of the halo. Supraglottic airways were used successfully in many patients. There was a significant increase in the number of patients classed as Cormack and Lehane grades 3 or 4 on direct laryngoscopy with the halo in situ compared with before the halo was applied. The incidence of intubation using fiberoptic or videolaryngoscopy was higher with the halo in situ. Multiple intubation attempts were required in 3.4% (1/29) of patients undergoing anesthesia for halo placement compared with 15.1% (11/73) undergoing anesthesia with a halo in situ. Airway management in children with cervical spine pathology should be anticipated to be more difficult than the general pediatric population. This is likely to be due to co-existing pathology associated with cervical spine disease in children, limitation of neck movement to prevent further neurological injury, and the halo itself limiting access to the head. We recommend advanced preparation, and ensuring the immediate availability of an anesthetist with skills in managing the pediatric difficult airway to avoid complications in this patient population.

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.

The knowledge of Cormack-Lehane intubation grade and intensive care unit outcome.

For patients on invasive mechanical ventilation (MV), it is unclear if knowledge of intubation grade influences intensive care unit (ICU) outcome. We aimed to determine if there was an independent relationship between knowledge of intubation grade during ICU admission and in-hospital mortality. We performed a retrospective cohort study of all patients receiving invasive MV at the Alfred ICU between December 2011 and February 2015. Demographics, details of admission, the severity of illness, chronic health status, airway detail (unknown or known Cormack-Lehane (CL) grade), MV duration and in-hospital mortality data were collected. Univariable and multivariable analyses were conducted to assess the relationship. The primary outcome was in-hospital mortality, and the secondary outcome was the duration of MV. Amongst 3556 patients studied, 611 (17.2%) had an unknown CL grade. Unadjusted mortality was higher in patients with unknown CL grade compared to known CL grade patients (21.6% vs. 9.9%). After adjusting for age, sex, severity of illness, type of ICU admission, cardiac arrest, limitations to treatment and diagnosis, having an unknown CL grade during invasive MV was independently associated with an increase in mortality (adjusted OR 1.5, 95% CI 1.14-1.98, p < 0.01). Amongst ICU patients receiving MV, not knowing CL grade appears to be independently associated with increased mortality. This information should be communicated and documented in all patients receiving MV in ICU.

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.

A prospective crossover study evaluating the efficacy of king vision video laryngoscope in patients requiring general anesthesia with endotracheal intubation

Background:Direct laryngoscopy used for tracheal intubation requires aligning the pharyngeal, laryngeal and oral axes to achieve a line of sight. Video laryngoscopy provides a better view of the glottis without the need for aligning the three axes.Aims:To evaluate the effectiveness of King vision laryngoscope over Macintosh laryngoscope in visualizing the glottis and intubating the trachea, when used on a same patient as in a cross over manner.Settings and Design:Department of Anaesthesia, Mediciti Institute of Medical Sciences, prospective crossover study conducted over a period of six months.Subjects and Methods:Sixty adult patients belonging to ASA physical status class I-II, requiring tracheal intubation were randomly assigned to intubation by King vision or Macintosh laryngoscope. Improvement, if any, in the Cormack-Lehane grading using the King vision scope, following initial grading with the Macintosh blade in the same patient was analyzed.Statistical Analysis:Mean and Standard deviation were calculated for different parameters under the study. Where appropriate, results were analyzed using the Mc Nemar χ2 test. A ‘p’ value less than 0.05 was considered statistically significant.Results:In the King Vision group, Cormack and Lehane grade improved in the majority (9/12) of patients in whom the initial Cormack and Lehane grade was >1 using the Macintosh blade.Conclusions:The use of the King vision blade significantly improved the laryngoscopic view over the Macintosh blade but the time for intubation was prolonged.

Addition of optics to laryngoscope design improves success of intubation: A prospective, observational study

Background: Many novel intubating videoscopes such as the GlideScope, McGrath®, Truview EVO2® videolaryngoscope (VLS), Airtraq® and C-MAC® VLS have been introduced in the recent past in an attempt to reduce airway-related morbidity and mortality. In this study, we aimed to compare the ease and success of intubation using Airtraq, Truview VLS and McCoy blade laryngoscope in non-difficult airway situations. Patients and Methods: Ninety patients with clinically normal airways belonging to American Society of Anesthesiologists Physical Status I–II were randomly assigned to be intubated using Airtraq (Group AL; n = 30), Truview VLS (Group TL; n = 30) or McCoy (Group ML; n = 30). The primary outcome measures were Intubation Difficulty Scale score and time for successful intubation. Assessment of modified Cormack–Lehane (MCL) grade at laryngoscopy, Percentage of Glottic Opening (POGO) score, haemodynamic variations, any optimisation manoeuvre required during endotracheal intubation, ease of intubation score and complications were the secondary outcomes. Results: The time for successful intubation was statistically significantly less with Airtraq as compared with both ML and Truview VLS (P 0.05). Conclusion: We conclude that both the Airtraq and Truview VLS are devices whose optical design improves intubating conditions in patients with non-difficult airways.

McGrath MAC video laryngoscope versus direct laryngoscopy for the placement of double-lumen tubes: A randomised control trial

Background and Aims:Role of video laryngoscopes (VLs) in the management of difficult airway with single-lumen tubes (SLTs) is established. VLs provide improved glottis view but are associated with longer time to intubate (TTI). We aimed to compare the TTI for double-lumen tube (DLT) insertion using the McGrath® MAC VL versus direct Macintosh laryngoscope (DL).Methods:Eleven senior anaesthesiologists experienced in SLT insertion, but not DLT insertion with VL participated. Seventy-four adults belonging to American Society of Anesthesiologists physical status I–II posted for elective surgery needing lung isolation were randomised to both intubator and laryngoscope (VL/DL). Primary endpoint was TTI; secondary endpoints included glottic view assessed by the Cormack and Lehane (CL) grade, need for external laryngeal manipulation, ease of intubation [scored using Numeric Rating Scale (1 – easiest, 10 – most difficult)] and associated complications. TTI was compared using Student's t-test.Results:No difference was found in TTI with DL and VL [(56.6 ± 14) s vs (64.4 ± 24) s, P = 0.104] as well as ease of use of laryngoscope [median score of 2 (1–3) in both]. Use of VL resulted in more patients with CL I glottic view – 86.0% versus 58.0% (P = 0.007). Fewer patients required external laryngeal manipulations (19% vs 47%, P = 0.013), and complications were fewer in the VL group (5% vs 24%, P = 0.023).Conclusion:TTI for DLT insertion was similar with VL and DL. However, VL was associated with better glottis visualisation, reduced need of external laryngeal manipulation and fewer complications.

Reliability of the thyromental height test for prediction of difficult visualisation of the larynx: A prospective external validation.

Background and Aims:Thyromental height (TMH) has been reported to be useful for prediction of difficult visualisation of the larynx (DVL), defined as Cormack--Lehane (C&L) grade III or IV. The aim of this study was to compare the diagnostic accuracy of the TMH test for DVL with that of other clinically used tests in Japanese patients.Methods:Six hundred and nine surgical patients undergoing endotracheal intubation under general anaesthesia were enrolled in this prospective observational study. TMH, thyromental distance (TMD), and Samsoon and Young's modified Mallampati (MMT) tests were performed in all patients. The C&L grades for the laryngoscopic view with and without external backward, upward, rightward pressure (BURP) were determined by designated airway assessors. The cutoff value for the TMH test was calculated using receiver-operating characteristic (ROC) curve analysis. The sensitivity, specificity, positive predictive value, accuracy, positive likelihood ratio, and area under the ROC curve (AUROC) for each predictive test were calculated and compared.Results:ROC curve analysis indicated that 54 mm is the optimal cutoff value for the TMH test. However, both this value and the conventional cutoff value of 50 mm, which has been reported as having good diagnostic accuracy in the literature, had poor diagnostic accuracy. The AUROC for the TMH test was 0.631 without BURP and 0.592 with BURP; these values were not superior to those for the TMD test or MMT.Conclusion:The TMH test is not a good predictor of DVL in Japanese patients.

GlideScope versus D-blade for tracheal intubation in cervical spine patients: A randomised controlled trial.

Background and Aims:Airway management in patients with cervical spine pathology is challenging. The aim of the study was to evaluate GlideScope (GVL) and D blade of C-MAC (CMAC-D) using manual inline axial stabilisation (MIAS) for tracheal intubation in patients with cervical spine injury/pathology.Methods:This is a randomised, single-blind, hospital-based study. After obtaining informed consent, 54 patients with cervical spine pathology/injury were grouped into GVL group or CMAC-D group, (n = 27 each) based on computer-generated random number table. Preoperative airway difficulty score (ADS) was calculated. The primary outcome of the study was intubation difficulty score (IDS) and the secondary outcomes included total time taken to secure airway, failure to intubate, haemodynamic parameters and adverse events. Data was represented in the form of number (%) or mean and standard deviation and median and interquartile range as appropriate. Chi square test was used for analysing IDS.Results:The mean ± SD of IDS of the CMAC-D and GVL groups were 0.04 ± 0.2 (0.04–0.11) and 0.19 ± 0.40 (0.03–0.34), respectively, (P value = 0.096). The number (%) of patients with IDS > 0 was 1 (3.7) in CMAC-D and 5 (18.5) in GVL group, (P value = 0.192). Demographic data, ADS, Cormack–Lehane grading, success rate, time of tracheal intubation, type of surgeries, haemodynamic parameters and post-operative complications were similar in both the groups.Conclusion:Both GVL and CMAC-D with MIAS are equally efficacious in tracheal intubation in cervical spine injury/pathology patients without other difficult airway management criteria.