Laryngeal View Research Articles

Chest anteroposterior diameter affects difficulty of laryngoscopy for non-morbidly obese patients

This prospective, observational study was performed to examine the hypothesis that if conventional 7-cm head elevation is applied, laryngoscopy is more difficult for patients with anteroposterior chest diameter (chest AP diameter) outside the average range (≥17.7 or ≤14.7 cm). Chest AP diameter at the sternal notch were measured preoperatively. All patients were placed on a surgical bed with an incompressible 7-cm pillow. During laryngoscopy, the laryngeal view was graded by use of the Cormack-Lehane classification. Difficult visualization of the larynx (DVL) was defined as a grade 3 or 4 view. DVL was observed for 49 patients (18.2 %). Differences between measured chest AP diameter for each patient and the calculated median value were used for statistical analysis. In univariate analysis, the difference between chest AP diameter and the median value was significantly related to DVL. Logistic regression analysis confirmed that the difference between chest AP diameter and the median value was an independent predictor of DVL (odds ratio, 3.900; 95 % confidence interval, 2.371-6.415; p < 0.001). Receiver operating characteristic curve analysis showed that this test with a test threshold of 1.5 cm had reasonable diagnostic accuracy (area under the curve of 0.748). When using a standard pillow size of 7 cm, chest AP diameter above or below the average range (≥17.7 or ≤14.7 cm) was a strong predictor of DVL for apparently normal-sized patients. In such cases, modification of pillow height should be considered.

Comparison of results from novice and trained personnel using the Macintosh laryngoscope, Pentax AWS(R), C-MAC(TM) and Bonfils intubation fibrescope: a manikin study

Indirect laryngoscopes offer improved laryngeal view and higher success rates of intubation, particularly for difficult airways. We hypothesised that: (a) the time required for intubation, overall success rates and ease of intubation with indirect laryngoscopes would be better than with the Macintosh laryngoscope; and (b) novices may achieve higher success rates and intubate faster using indirect laryngoscopes. In a cross-sectional observational study, 13 novices and 13 skilled anaesthetists were recruited. Participants were compared when intubating a manikin simulating normal and difficult airway scenarios using the Macintosh laryngoscope, Pentax Airway Scope® (AWS), C-MAC[TM] and Bonfils intubation fibrescope. There was no significant difference in intubation success rates between the groups. Skilled anaesthetists intubated faster than novices with Pentax AWS in the difficult airway scenario (22 s vs. 33 s, p = 0.047). The mean intubation times for C-MAC and Pentax AWS were shorter than for the Macintosh laryngoscope and Bonfils intubation fibrescope in both difficult (C-MAC: 24 s, Pentax AWS: 28 s, Macintosh: 80 s, Bonfils: 61 s; p < 0.001) and normal (C-MAC: 17 s, Pentax AWS: 19 s, Macintosh: 39 s, Bonfils: 38 s; p = 0.002) airway scenarios. We found that intubation success was more than 85% with all indirect laryngoscopes compared to 69% for the Macintosh laryngoscope. Both C-MAC and Pentax AWS achieved faster intubation times compared to the Macintosh laryngoscope and Bonfils intubation fibroscope for both airway scenarios. Skilled anaesthetists were 33% faster than novices when intubating a difficult airway using Pentax AWS.

A Feasibility Study Using the VivaSight Single Lumen™ to Intubate the Trachea Through the Fastrach Laryngeal Mask Airway

The VivaSight Single Lumen™ (SL) is new endotracheal tube with a video camera and a light source in the tip allowing continuous visual observation of the airway. In this study, we checked the feasibility of endotracheal intubation with a VivaSight-SL through the Fastrach Laryngeal Mask Airway(®) (FT-LMA). We studied 50 patients with normal airways, scheduled for elective surgery during general anesthesia requiring endotracheal intubation. The FT-LMA was inserted and once adequate ventilation was achieved, the VivaSight-SL was passed through the FT-LMA into the trachea under visual control. The following criteria were used to score the laryngeal view: grade 1: full view of the arytenoids and glottis; grade 2: epiglottis, arytenoids or glottic opening are partly visible, the structure of cords is difficult to see; grade 3: dark areas indicating an open space; and grade 4: no part of the larynx can be identified. The FT-LMA was placed successfully in 49 patients at the first attempt. One patient was excluded from the study after 2 failed attempts to ventilate with the FT-LMA. All 49 patients were successfully intubated with the VivaSight-SL, (95% confidence interval [CI] 0.89-0.99), 47 patients at the first attempt (95% CI, 0.83-0.98) and 2 patients at the second attempt. (95% CI, 0.004-0.13). The time to achieve an effective airway with the FT-LMA was 15.4 ± 6 (mean ± SD) seconds. The time to achieve a laryngeal view with the VivaSight-SL was 28.8 ± 5 seconds. Correct position of the VivaSight-SL was confirmed with visualization of the carina. Time of successful intubation with VivaSight-SL from picking up the VivaSight-SL to observing a end-tidal CO(2) curve was 45 ± 7 seconds. After introducing the VivaSight-SL through the intubating channel of the FT-LMA, a grade 1 view was obtained in 18 patients, grade 2 in 18 patients, a grade 3 in 4 patients, and grade 4 in 9 patients. The high first-attempt intubation success rate using the VivaSight-SL to intubate the trachea through a FT-LMA makes this technique an attractive and promising concept.

Comparative Effectiveness of the C-MAC Video Laryngoscope Versus Direct Laryngoscopy in the Setting of the Predicted Difficult Airway

Aziz, Michael F.*; Dillman, Dawn*; Fu, Rongwei†; Brambrink, Ansgar M.* Author Information

Videographic Analysis of Glottic View With Increasing Cricoid Pressure Force

Cricoid pressure may negatively affect laryngeal view and compromise airway patency, according to previous studies of direct laryngoscopy, endoscopy, and radiologic imaging. In this study, we assess the effect of cricoid pressure on laryngeal view with a video laryngoscope, the Pentax-AWS. This cross-sectional survey involved 50 American Society of Anesthesiologists status I and II patients who were scheduled to undergo elective surgery. The force measurement sensor for cricoid pressure and the video recording system using a Pentax-AWS video laryngoscope were newly developed by the authors. After force and video were recorded simultaneously, 11 still images were selected per 5-N (Newton; 1 N = 1 kg·m·s(-2)) increments, from 0 N to 50 N for each patient. The effect of cricoid pressure was assessed by relative percentage compared with the number of pixels on an image at 0 N. Compared with zero cricoid pressure, the median percentage of glottic view visible was 89.5% (interquartile range [IQR] 64.2% to 117.1%) at 10 N, 83.2% (IQR 44.2% to 113.7%) at 20 N, 76.4% (IQR 34.1% to 109.1%) at 30 N, 51.0% (IQR 21.8% to 104.2%) at 40 N, and 47.6% (IQR 15.2% to 107.4%) at 50 N. The number of subjects who showed unworsened views was 20 (40%) at 10 N, 17 (34%) at 20 and 30 N, and 13 (26%) at 40 and 50 N. Cricoid pressure application with increasing force resulted in a worse glottic view, as examined with the Pentax-AWS Video laryngoscope. There is much individual difference in the degree of change, even with the same force. Clinicians should be aware that cricoid pressure affects laryngeal view with the Pentax-AWS and likely other video laryngoscopes.

Jaw-thrust induces sympathetic responses during induction of general anesthesia

BackgroundJaw-thrust is a noxious stimulus that might induce sympathetic responses. The purpose of this study, was to evaluate the effects of jaw-thrust on sympathetic responses.MethodsWe investigated seventy three patients. Patients who received general anesthesia were randomly divided into a control group (maintenance of combined airway maneuver with head tilt, open mouth by mouthpiece, and chin-lift, n = 30) and jaw-thrust group (maintenance of head tilt, open mouth and jaw-thrust, n = 30). In the jaw-thrust group, four minutes of endoscopy-guided force to the mandible to get the best laryngeal view were applied. For the control group, the combined airway maneuver was maintained during the same period. Arterial blood pressure (AP) and heart rate (HR) were recorded at predetermined time points (1 min before anesthesia induction, 2 min after fiberoptic bronchoscopy placement, and thereafter 1 min-interval during each airway maneuver) during jaw-thrust and chin-lift maneuver. The force amplitude applied for best laryngeal view during jaw-thrust was also measured.ResultsPeak systolic and diastolic AP increased 39.0 ± 17.6 and 39.9 ± 22.8 mmHg from the baseline (P < 0.001) in the jaw-thrust group. HR was also 32.5 ± 19.4 beats/min from the baseline (P < 0.001) in the jaw-thrust group. These remained high at all time points, compared with the control group (P < 0.01). The force magnitude applied for jaw-thrust was not correlated to the AP and HR changes (P > 0.05).ConclusionsPerforming the jaw-thrust maneuver induces significant sympathetic responses, irrespective of the force magnitude.

To assess the efficacy of i-gel for ventilation, blind tracheal intubation and nasogastric tube insertion.

Background:The i-gel is a novel supraglottic airway device with a soft and non-inflatable cuff. In our study we attempted to evaluate the performance of i-gel as a ventilatory device, as a conduit to blind tracheal intubation using conventional polyvinyl chloride tracheal tube and gastric tube insertion through it.Materials and Methods:A total of 180 patients of American Society of Anesthesiologist (ASA) physical status I/II undergoing elective surgery under general anesthesia were included in this study. After induction of anesthesia, i-gel was inserted and the following parameters were recorded: Time taken for successful i-gel insertion, airway leak pressures, ease of gastric tube insertion and laryngeal view using fiberscope. Following this blind tracheal intubation was attempted. First attempt and overall success rate in blind tracheal intubation and gastric tube insertion were evaluated and tracheal intubation time was measured. Also presence of any side effects or complication following removal was recorded.Results:We achieved a 100% success rate in insertion of i-gel and in 171 out of 180 patients; i-gel was inserted in the 1st attempt itself. We also were able to achieve an overall success rate for blind endotracheal intubation via i-gel in 78.33% cases, and successful gastric tube placement was possible in 92.22%. In our study we also achieved a leak pressure of 25.52 (±2.33) cm of H2O.Conclusion:I-gel may be effectively used for ventilation, nasogastric tube insertion and as a conduit to blind endotracheal intubation with minimal complication and acceptable airway sealing pressures.

A comparison of Truview EVO2 laryngoscope with Macintosh laryngoscope in routine airway management: A randomized crossover clinical trial

Background:The Truview EVO2 blade facilitates the view of vocal cords by indirect laryngoscopy and does not require the proper alignment of the oral, pharyngeal and tracheal axes as with the Macintosh blade.Methods:In a crossover fashion, we prospectively compared the view obtained at laryngoscopy with Truview EVO2 and the Macintosh blade in 110 adult patients of either sex between the age of 18 and 60 years, who were scheduled to undergo general anesthesia with endotracheal intubation. The patients were intubated with the second laryngoscope. The preoperative airway variables, laryngoscopic view, difficulty of intubation scale (IDS) score, duration of intubation, and degree of difficulty percentage of glottic opening (POGO score) of use with each laryngoscope were compared.Results:The IDS score was low and comparable between the two laryngoscopes. The laryngeal view was easy; Modified Cormack Lehane (MCL) grade 2a or less in 98.14% of the cases with the Truview laryngoscope compared to 78.7% of the cases with the Macintosh laryngoscope. Nineteen patients of MCL grade 3, one patient of grade 2b, and seven patients of grade 2a view with the Macintosh laryngoscope had MCL grade 1 view with the Truview laryngoscope. The duration of intubation was comparable between Truview and Macintosh laryngoscopes (12.1±3.8 s vs. 10.9±2.1 s).Conclusion:Truview laryngoscope performed comparably to Macintosh laryngoscope in patients with normal airway; however, the Truview laryngoscope may be a better option in difficult airway situations when the Macintosh blade fails to show the glottic opening.

The use of the Clarus Video System for double-lumen endobronchial tube intubation in a patient with a difficult airway

The use of the Clarus Video System for double-lumen endobronchial tube intubation in a patient with a difficult airway

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.

ACCURACY OF THE UPPER LIP BITE TEST;

Objective: To compare the accuracy of Upper lip bite test with modified Mallampati classification for predicting the difficultlaryngoscopic intubation. Study Design: Cross sectional Study. Place and duration of study: The study was carried out at Department ofAnaesthesiology, Intensive Care and Pain management, Combined Military hospital, Rawalpindi from September 2008 to August 2009.Patients and Methods: Four hundred patients undergoing elective surgery meeting the inclusion/exclusion criteria were enrolled afterwritten informed consent. The airways of the patients were evaluated by using the modified Mallampati classification (MMP) and theUpper lip bite test (ULBT). MMP class 3 or 4 and ULBT class 3 were considered as indicators of difficult intubation. The laryngeal view wasgraded by Cormack and Lehane classification (Gold standard). Grade 1 or 2 was considered to represent easy intubation and grade 3 or 4to represent difficult intubation. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy werecalculated for both the tests separately by using the 2×2 table. Results: ULBT had a higher accuracy of 94%, specificity of 99.2% andpositive predictive value 70% compared to MMP accuracy of 82.7%, specificity of 84.4% and positive predictive value of 22.7%.Conclusions: The diagnostic accuracy of the Upper lip bite test was more than the modified Mallampati classification. We suggest that itbe compared with the other prevailing tests as well which are often used to assess difficult intubations.

A randomised comparison of InnoScope and Macintosh laryngoscope in simulated difficult tracheal intubation in manikins

We conducted a crossover randomised study to evaluate the performance of a novel optical stylet, the InnoScope, for tracheal intubation in simulated normal and difficult airways. Twenty-five anaesthetists attempted tracheal intubation on a SimMan 3G simulator using the InnoScope first followed by the Macintosh laryngoscope or vice versa. Three airway scenarios were tested: (1) normal airway; (2) difficult airway with swollen pharynx; and (3) limited neck movement. In each scenario, the laryngeal view, duration of and success rate for tracheal intubation were recorded. Compared with the Macintosh laryngoscope, the use of InnoScope increased the percentage of glottic opening seen by 17% in normal airway, 23% in the difficult airway and 32% with limited neck movement, p < 0.01. Despite this better laryngeal view, successful tracheal intubation achieved with the InnoScope (88.0%) was lower than that for the Macintosh laryngoscope (98.7%), p = 0.008. Using the InnoScope, tracheal intubation during the first attempt was only successful in 48% of cases with difficult airway. In this scenario, the median (interquartile range [range]) duration of tracheal intubation was significantly longer with [corrected] InnoScope compared with the Macintosh laryngoscope, (70 (19-120 [15-120)] s vs 30 [21-58 (15-120)] s, [corrected] p = 0.01. We conclude that an improved laryngeal view with the use of the InnoScope did not translate into better conditions for tracheal intubation.

The ProSeal Laryngeal Mask Airway is more effective than the LMA-Classic in pediatric anesthesia: a meta-analysis

Study ObjectiveTo determine, in pediatric patients, whether the ProSeal Laryngeal Mask Airway (PLMA) has advantages over the LMA-Classic (cLMA) in leak pressure, placement difficulty, incidence of adverse events, postoperative blood staining, laryngospasm, bronchospasm, and hoarseness. DesignMeta-analysis. SettingMetropolitan university medical center. MeasurementsMEDLINE (1966–2011), EMBASE (1980–2011), and the CENTRAL (1977–2011) databases was searched for randomized controlled trials (RCTs). The relative risk (RR), mean difference (MD), and corresponding 95% confidence intervals (CIs) were calculated using RevMan 5 statistical software for dichotomous and continuous outcomes, respectively. Main ResultsOf the 13 RCTs that met study inclusion criteria, 8 trials comprising 557 patients were analyzed. Leak pressure was higher in the PLMA (RR = 5.02, 95% CI = 3.64, 6.4). The difference in rate of successful placement on the first attempt did not differ between the two devices (RR = 1.00, 95% CI = 0.94, 1.06). The incidence of gastric insufflation was lower with the PLMA (RR = 0.20, 95% CI = 0.07, 0.61). The incidence of postoperative blood staining on the mask did not differ (RR = 1.08, 95% CI = 0.52, 2.21), nor was there any difference between the two devices in incidence of laryngospasm or bronchospasm (RR = 0.75, 95% CI = 0.18, 3.21), or hoarseness (RR = 3.00, 95% CI = 0.13, 70.83). There was no difference in laryngeal view between the PLMA and cLMA (RR = 1.06, 95% CI = 0.90, 1.26). The maximum tidal volume per kg was greater with the PLMA (MD = 4.16, 95% CI = 3.56, 4.76). ConclusionsThe PLMA (in sizes 1,1.5, 2, and 2.5) offers some advantages over the cLMA in pediatric anesthesia.

English

BACKGROUND - Laryngeal Mask Airway (LMA) CTrach is a supraglottic device which is functionally identical to Intubating Laryngeal Mask airway (ILMA) which enables ventilation and allows real time visualization of endotracheal intubation. This study aimed at assessing the ease and efficacy of using LMA CTrach for orotracheal intubation in anaesthetized but unparalysed patients. MATERIAL AND METHODS : 40 patients of ASA Grade I/ II scheduled for elective surgeries requiring orotracheal intubation were studied. Anaesthesia was induced with fentanyl 1 µg.kg -1 and sevoflurane. Neuromuscular blockers were not used. After CTrach insertion, various corrective manoeuvres were used to obtain the best laryngeal view. Two ml of 2% lignocaine was instilled over the vocal cords via a small sized catheter and tracheal intubation was performed after 2 minutes. The haemodynamic parameters were recorded. Any complications occurring following the CTrach insertion or tracheal intubation and those in the post operative period were also recorded. RESULTS : The insertion of CTrach was easy and well tolerated in all the patients. Thirty percent of patients required corrective manoeuvres. Tracheal intubation was successful in all 40 patients in first or second attempt. The problems encountered were hypotension following tracheal intubation in 20% patients and bucking over the tube at the time of CTrach removal in 17.5% patients. Hypotension persisted only for 2-3 minutes. In the post operative period, mild sore throat and pain on swallowing were complained by four patients each, which resolved within 24 hours. CONCLUSION - The use of LMA CTrach to ventilate lungs and facilitate tracheal intubation in anaesthetized unparalysed patients appears to be a useful and safe technique as it does not

Nasotracheal intubation by combined use of a Bullard™ laryngoscope and a cuff inflation technique in a patient with a severely restricted mouth opening

To the Editor, The Bullard laryngoscope (Circon ACMI, Stamford, CT, USA) is an anatomically shaped rigid fibreoptic laryngoscope that has been used for more than two decades. One of its unique characteristics is a very thin blade that requires only a 6-mm mouth opening for insertion. We report a case in which nasotracheal intubation was performed by combined use of a Bullard laryngoscope and a cuff inflation technique in a patient with a severely restricted mouth opening. The patient provided written informed consent for publication of this case. A 66-yr-old male patient, 157 cm tall and weighing 45.5 kg, was scheduled for keratoplasty. The size of his mouth opening was only about 9.5 mm because of previous radiation therapy for maxillary sinus cancer; thus, nasotracheal intubation was planned for airway management. The Bullard laryngoscope was selected for this procedure instead of a fibrescope because with the fibrescope, the tracheal tube is advanced in a blind manner and this may cause airway trauma; arytenoid cartilage dislocation or vocal cord trauma. General anesthesia was induced with fentanyl 150 lg and propofol 30 mg. Bag and mask ventilation was performed successfully, and then rocuronium 40 mg and remifentanil 0.3 lg kg min were administered. Even after neuromuscular blockade, no additional mouth opening was obtained. A 7.5-mm internal diameter tracheal tube was inserted nasally, and the Bullard laryngoscope was inserted orally to lift the epiglottis directly. A laryngeal view was easily obtained through the eyepiece of the Bullard laryngoscope, and then the tracheal tube was advanced carefully into the field of view. Before the laryngeal inlet was reached, the tracheal tube cuff was inflated to lift the tube tip and direct it towards the vocal cords. The cuff was then deflated to pass through the vocal cords. The tracheal tube was successfully inserted into the trachea, and general anesthesia was maintained throughout the operation without any complications. Also, no complications were encountered during postanesthesia rounds. In the past several years, anatomically shaped indirect laryngoscopes with a tracheal tube guide channel, such as the Pentax Airway Scope (HOYA, Tokyo, Japan) and the Airtraq (Prodol Meditec SA, Vizcaya, Spain), have become very popular and have been reported to be useful in airway management. Although several studies have shown that the Airway Scope and Airtraq are more useful than the Bullard laryngoscope for orotracheal intubation and even for nasotracheal intubation, these laryngoscopes have a bulky blade configuration because the tube channel is thicker than the tube diameter (Figure). Even the version of the Airtraq designed for nasotracheal intubation, which is devoid of a tube guide channel, requires an 18-mm mouth opening for insertion; therefore, in our case, the thinner blade of the Bullard laryngoscope was adequate to obtain a laryngeal view. The alternative approaches we could have considered in our case include a fibreoptic bronchoscopic intubation or a lightwandguided technique through the nostril. However, both techniques involve tracheal tube advancement in a blind manner, which may cause trauma, particularly to the arytenoid cartilage or vocal cords. A Bullard laryngoscope-assisted nasotracheal intubation can be a useful approach in patients with a severely restricted mouth opening because it provides a good laryngeal view and continuous observation of tube insertion throughout the procedure. A. Tampo, MD, PhD (&) A. Suzuki, MD, PhD M. Matsumoto, MD H. Iwasaki, MD, PhD Asahikawa Medical University, Asahikawa, Hokkaido, Japan e-mail: atampo1031@gmail.com

Anesthetic implications of infants with mandibular hypoplasia treated with mandibular distraction osteogenesis

To document the incidence of difficult intubation following mandibular distraction osteogenesis (MDO) in children with severe mandibular hypoplasia. Syndromes associated with significant mandibular hypoplasia, especially Pierre Robin sequence, provide a challenge in airway management both in and out of the operating room. Mandibular advancement using mandibular distraction osteogenesis devices has been used in infants in an attempt to reduce the incidence of acute life-threatening airway obstruction. Whether MDO also reduces the incidence of difficult intubation has not been adequately described. A retrospective chart review of 51 infants with upper airway obstruction secondary to mandibular hypoplasia who required MDO between January 2002 and 2012. The primary outcome was the incidence of difficult or failed intubation. Secondary outcomes were the relationship between syndrome type and the incidence of difficult intubation. Fifty-one PRS infants were identified. Twenty-eight patients had isolated PRS, six had syndromic PRS, seven had Treacher Collins syndrome, and 10 had another coexisting syndrome. Prior to mandibular distraction osteogenesis (MDO), the incidence of difficult intubation was 71%, with the highest incidence in patients with Treacher Collins syndrome (100%), sPRS syndrome (100%), and PRS (65%). Following MDO, the incidence of difficult intubation was 8.3%. The difference was statistically significant for all patients (Kruskal-Wallis rank test P = 0.0001) those with isolated PRS (P = 0.0001), syndromic PRS (P = 0.0023), and other syndromes (P = 0.0002), but not for Treacher Collins syndrome (P = 0.21). Three patients had pre existing tracheostomies. In a select group of infants with severe upper airway obstruction who have failed nonsurgical airway interventions, mandibular distraction osteogenesis reduces the incidence of difficult mask ventilation and difficult intubation. We were not able to compare the improvement in airway management to a comparable group of PRS infants who did not undergo surgical intervention. The improvement in laryngeal view was most marked for infants with isolated PRS but no significant benefit was demonstrated in infants with TCS.

Observational trials and airway devices: more to it than just sample size

Observational trials and airway devices: more to it than just sample size

Comparative Performance of Direct and Video Laryngoscopes in Patients with Predicted Difficult Airway

Comparative Performance of Direct and Video Laryngoscopes in Patients with Predicted Difficult Airway

The use of AIR-Q as conduit for fiberoptic endotracheal intubation in adult paralyzed patients

BackgroundThe AIR-Q Laryngeal Mask (Cookgas LLC; distributed by Mercury Medical) is a supraglottic device present in the market since 2004. It has different sizes for pediatric and adult use. This device proved to be of utmost importance in the management of difficult airway [1]. The study evaluates the different adult sizes of the Air Q when used for intubation regarding the ease of insertion, the laryngeal view grade, their efficacy as conduit for standard cuffed endotracheal tubes using fiberoptic bronchoscope. The study also records the time of intubation, the ease and time of removal of the AIRQ over a removal stylet without dislodgement of the tube from trachea. Any complications related to the use of AIRQ were also recorded such as laryngeal oedema, blood streaked mucous, trauma to the airway, laryngeal spasm or aspiration.MethodsSixty adult patients aged 20–50 years, ASA I, II undergoing elective surgeries requiring general anesthesia, were enrolled in the study. The patients were divided into 2 equal groups according to their body weight. The body weight of the first group ranged from 50 to 70 kg and used the Air Q 3.5 for intubation with an endotracheal tube (ETT) 7 mm ID, while the body weight of the second group ranges from 70 to 100 kg and used the Air Q 4.5 for intubation with a tube 7.5 mm ID. The number of attempts of insertion, the seal pressure, the laryngeal view grade, the time and the number of attempts of intubation, time of removal of the AIRQ over the tube without dislodgement, and any complications related to the use of AIRQ were recorded such as laryngeal oedema, blood streaked mucous, trauma to the airway, laryngeal spasm or aspiration.ResultsThe insertion and removal of the AIRQ were easy and successful in all patients of both groups. The endotracheal intubation by fiberoptic bronchoscope through the Air Q was successful and easy in both groups. Grade 5 laryngeal view was seen with AIRQ 4.5 in some patients with higher body weight.ConclusionThe insertion of AIRQ in adult patients is easy and provides an effective conduit for the standard cuffed endotracheal tubes using fiberoptic bronchoscope. The removal of the AIRQ over the removal stylet is easy without dislodgement of the tube. Because of higher incidence of down folding of the epiglottis in some obese patients, they are better intubated under direct vision with the use of fiberoptic bronchoscope.

A randomized trial comparing the Ambu®Aura‐i™ with the air‐Q™ intubating laryngeal airway as conduits for tracheal intubation in children

To assess the clinical performance of the Ambu Aura-i (Aura-i) in children. To compare the Aura-i with the air-Q intubating laryngeal airway (air-Q) for the purposes of fiberoptic-guided tracheal intubation. The Aura-i is a new supraglottic airway designed for tracheal intubation. One hundred twenty children, ages 1 month to 6 years, were randomized to receive either the Aura-i or air-Q, and divided into three equal subgroups (Group 1, 2, 3) based on weight. The time for successful tracheal intubation was primarily assessed. The ease, time, and number of attempts for successful device insertion, leak pressures, fiberoptic grade of laryngeal view, number of attempts time for removal of the device after tracheal intubation, and complications were secondarily assessed. Device placement, tracheal intubation, and removal after tracheal intubation were successful in all patients. There were no differences in the time to successful tracheal intubation through the Aura-i (32.9 ± 13.3 s), and the air-Q (33.9 ± 13 s; P = 0.68), or fiberoptic grade of view between devices. There was not a statistically significant correlation between the time to intubation and the fiberoptic grade of laryngeal view in any of the groups. There were no statistically significant differences in the overall leak pressures, air-Q (18.3 ± 6.1 cm H(2) O) vs Aura-i (16 ± 5.1 cm H(2) O; P = 0.05). In Group 1 (5-10 kg), leak pressures were higher with the air-Q (23.4 ± 7.2 cm H(2) O) than the Aura-i (16.1 ± 5.2 cm H(2) O; P = 0.001). There were no statistically significant differences in the time for removal between the two devices (P = 0.11). However, with the size 1.5 Aura-i, the pilot balloon of the tracheal tube was removed in order to facilitate the removal of the device after tracheal intubation. Both devices served as effective conduits for fiberoptic-guided tracheal intubation. The limitation of the narrower proximal airway tube of the size 1.5 Aura-i should be considered if cuffed tracheal tubes are to be utilized.