Easy and difficult nasal intubation--a randomised comparison of Macintosh vs Airtraq® laryngoscopes

Video laryngoscopy vs. direct laryngoscopy for nasotracheal intubation in oro-maxillofacial surgery: a systematic review and meta-analysis of randomized controlled trials

Background

Nasotracheal intubation (NTI) is commonly performed in oromaxillofacial surgeries. We did this meta-analysis to ascertain whether use of video laryngoscopy (VL) provided better NTI characteristics as compared to direct laryngoscopy (DL) in patients undergoing oromaxillofacial surgeries.

Methods

We performed a systematic search to identify randomized controlled trials comparing VL with DL for NTI in adults undergoing elective oromaxillofacial surgery. The primary outcome was time to intubation. Secondary outcomes included the first attempt success, overall success, incidence of nasal bleeding, Cormack and Lehane grade, and maneuvers required.

Results

Of the 456 studies identified following a systematic search, 10 were included. Meta-analysis showed a significantly lower time to tracheal intubation favoring VL (mean difference: –9.04, 95% CI [–12.71, –5.36], P < 0.001; I² = 59%). VL was also associated with a greater first attempt success (relative risk [RR]: 1.10, 95% CI [1.04, 1.16], P = 0.001). Maneuvers to facilitate intubation were less with VL (RR: 0.22, 95% CI [0.10, 0.51], P < 0.001). There was no difference in overall intubation success (RR: 1.04, 95% CI [0.98, 1.10], P = 0.17). The incidence of bleeding did not differ between the DL and VL groups (RR: 0.59, 95% CI [0.32, 1.08], P = 0.09).

Conclusions

Evidence as per this meta-analysis suggests VL leads to a shorter time to NTI, a greater first attempt success rate, and reduced need for maneuvers when compared to DL. The present study supports use of VL as a first line device for NTI in oral-maxillofacial surgeries in experienced hands.

Comparison of C-MAC D-blade videolaryngoscope and McCoy laryngoscope efficacy for nasotracheal intubation in simulated cervical spinal injury: a prospective randomized comparative study

BACKGROUND

Immobilization with cervical spine worsens endotracheal intubation condition. Though various intubation devices have been demonstrated to perform well in oral endotracheal intubation, limited information is available concerning nasotracheal intubation (NTI) in patients with cervical spine immobilization. The present study compared the performance of the C-MAC D-Blade videolaryngoscope with the McCoy laryngoscope for NTI in patients with simulated cervical spine injuries.

METHODS

This was a prospective, randomized, controlled, study done in a tertiary hospital. Ninety-five patients requiring NTI were included in data analysis: McCoy group (group M, n = 47) or C-MAC D-Blade videolaryngoscope group (group C, n = 48). A Philadelphia neck collar was applied before anesthetic induction to immobilize the cervical spine. Single experienced anesthesiologist performed NTI. The primary outcome was duration of intubation divided by three steps: nose to oropharynx; oropharynx into glottic inlet; and glottic inlet to trachea. Secondary outcomes included glottic view as percentage of glottis opening (POGO) score and Cormack-Lehance (CL) grade, modified nasal intubation-difficulty scale (NIDS) rating, hemodynamic changes before and after intubation, and complications.

RESULTS

Total intubation duration was significantly shorter in group C (39.5 ± 11.4 s) compared to group M (48.1 ± 13.9 s). Group C required significantly less time for glottic visualization and endotracheal tube placement in the trachea. More patients in group C had CL grade I and higher POGO scores (P <  0.001, for both measures). No difficulty in NTI (modified NIDS = 0) was more in group C than group M. Hemodynamic changes and incidence of complications were comparable between groups.

CONCLUSION

The C-MAC D-Blade videolaryngoscope is an effective tool for NTI in a simulated difficult airway, which improves glottic visualization and shortens intubation time relative to those with McCoy laryngoscope.

TRIAL REGISTRATION

Clinical Research Information Service of the Korea National Institute of Health, Identification number: KCT 0004535, Registered December 10, 2019, Retrospectively registered, http://cris.nih.go.kr.

Video Versus Direct Laryngoscopy for Inpatient Emergency Intubation in Adults

BACKGROUND

Emergency intubation carries a higher risk of complications than elective airway management. Video laryngoscopy (VL) could potentially improve patient safety. The goal of this study was to determine whether VL is superior to direct laryngoscopy for the emergency intubation of adults in the inpatient setting.

METHODS

Pertinent studies were retrieved by a systematic literature search in the MEDLINE, Embase, and CENTRAL databases. The selection of studies, data extraction, and assessment of the potential for bias were carried out independently by two of the authors. Effect sizes were reported as odds ratios (OR) or mean differences (MD). The primary endpoint was successful intubation at the first attempt. Further variables were considered as secondary endpoints.

RESULTS

1098 titles and abstracts were retrieved, and the full texts of 43 articles were examined. Eight randomized and controlled trials, with a total of 1796 patients, were analyzed. VL was not found to confer any statistically significant advantage with respect to successful intubation at the first attempt (OR 0.72, 95% confidence interval [0.47; 1.12]) or with respect to the time to successful intubation (MD -8.99 seconds [-24.00; 6.01]). On the other hand, the use of VL was significantly associated with a lower number of intubation attempts (MD -0.17 [-0.31; -0.03]) and with a lower frequency of esophageal intubation (OR 0.27 [0.10; 0.75]).

CONCLUSION

The routine use of VL for airway management in emergency medicine might improve patient safety, as VL is associated with a lower number of intubation attempts and with a lower frequency of esophageal intubation. Further randomized controlled trials are needed before any definitive conclusions can be drawn about the advantages of video laryngoscopy.

A comparison of McGrath MAC, Pentax AWS, and Macintosh direct laryngoscopes for nasotracheal intubation: a randomized controlled trial

Purpose

Videolaryngoscopy in nasotracheal intubation has been reported to be better than direct laryngoscopy. The most suitable type of videolaryngoscope remains unknown. This study aimed to compare two videolaryngoscopes (McGrath MAC and Pentax AWS) with a Macintosh laryngoscope during nasotracheal intubation.

Methods

Overall, 123 patients older than 18 with normal airways who needed nasotracheal intubation were randomly allocated into three groups: Macintosh (n=41), McGrath (n=41), and Pentax (n=41). Intubation time was the primary outcome and subdivided into three steps: nose to oropharynx, oropharynx to laryngeal inlet, and laryngeal inlet to trachea. Time required, ease of each step, glottic view grade, modified nasal intubation–difficulty score, and subjective difficulty were evaluated.

Results

Intubation time among the three groups was not significantly different (Macintosh 34.6±8.1 seconds, McGrath 35.2±7.9 seconds, Pentax 36.2±9.7 seconds; p=0.727). While the glottal view was better with videolaryngoscopes (I/IIa/IIb/III 36.6%/36.6%/19.5%/7.3% vs 82.9%/9.8%/7.3%/0%, vs 63.4%/29.3%/4.9%/2.4%, p=0.000), modified nasal intubation–difficulty score and subjective difficulty and ease of each step were not significantly different. However, the Pentax took longest for the second step (11.8±6.3 vs 10.3±3.5 vs 15.1±7.6 seconds, p=0.001) but was shortest for the third step (2.9±2.6 vs 4.4±5.6 vs 1.7±0.7 seconds, p=0.001).

Conclusion

The McGrath MAC and Pentax AWS showed no benefits in intubation time or difficulty, despite better glottal views, compared to the Macintosh laryngoscope in nasotracheal intubation. Additionally, videolaryngoscopes had variable performance at different steps of nasotracheal intubation.

A randomized controlled comparison of non-channeled king vision, McGrath MAC video laryngoscope and Macintosh direct laryngoscope for nasotracheal intubation in patients with predicted difficult intubations

BACKGROUND

King Vision and McGrath MAC video laryngoscopes (VLs) are increasingly used. The purpose of this study was to evaluate the performance of nasotracheal intubation in patients with predicted difficult intubations using non-channeled King Vision VL, McGrath MAC VL or Macintosh laryngoscope by experienced intubators.

METHODS

Ninety nine ASA I or II adult patients, scheduled for oral maxillofacial surgeries with El-Ganzouri risk index 1-7 were enrolled. Patients were randomly allocated to intubate with one of three laryngoscopes (non-channeled King Vision, McGrath MAC and Macintosh). The intubators were experienced with more than 100 successful nasotracheal intubations using each device. The primary outcome was intubation time. The secondary outcomes included first success rate, time required for viewing the glottis, Cormack-Lehane grade of glottis view, the number of assist maneuvers, hemodynamic responses, the subjective evaluating of sensations of performances and associated complications.

RESULTS

The intubation time of King Vision and McGrath group was comparable (37.6 ± 7.3 s vs. 35.4 ± 8.8 s) and both were shorter than Macintosh group (46.8 ± 10.4 s, p < 0.001). Both King Vision and McGrath groups had a 100% first attempt success rate, significantly higher than Macintosh group (85%, p < 0.05). The laryngoscopy time was comparable between King Vision and McGrath group (16.7 ± 5.5 s vs. 15.6 ± 6.3 s) and was shorter than Macintosh group (22.8 ± 7.2 s, p < 0.05) also. Compared with Macintosh laryngoscope, Glottis view was obviously improved when exposed with either non-channeled King Vision or McGrath MAC VL (p < 0.001), and assist maneuvers required were reduced (p < 0.001). The maximum fluctuations of MAP were significantly attenuated in VL groups (47.7 ± 12.5 mmHg and 45.1 ± 10.3 mmHg vs. 54.9 ± 10.2 mmHg, p < 0.05 and p < 0.01). Most device insertions were graded as excellent in McGrath group, followed by Macintosh and King Vision group (p = 0.0014). The tube advancements were easier in VLs compared with the Macintosh laryngoscope (p < 0.001). Sore throat was found more frequent in Macintosh group compared with King Vision group (p < 0.05).

CONCLUSIONS

Non-channeled King Vision and McGrath MAC VLs were comparable and both devices facilitated nasotracheal intubation in managing predicted difficult intubations compared with Macintosh laryngoscope.

TRIAL REGISTRATION

ClinicalTrials registration number NCT03126344 . Registered on April 24, 2017.

Which nostril should be used for nasotracheal intubation with Airtraq NT®: the right or left? A randomized clinical trial

Background/aim

Nasotracheal Airtraq is specifically designed to improve the glottis view and ease the nasotracheal intubation process in normal and difficult cases.

Materials and methods

After Ethics committee approval, we decided to enroll 40 patients with an ASA physical status of I or II, between 18 and 70 years of age undergoing elective maxillofascial, oral, and double chin surgery to determine which nostril is more suitable for nasotracheal intubation with nasotracheal Airtraq. Patients were randomized into the right and left nostril groups.

Results

Demographic and airway characteristics were similar among the groups. Nasotracheal intubation through the right nostril was shorter than that of the left nostril during nasotracheal intubation with the Airtraq NT (P < 0.001). 90° counterclockwise rotation of the tip of the tube was needed for directing the tube into the vocal cords in both right and left nostril groups (72% vs 88%). External laryngeal pressure and head flexion maneuvers can ease the intubation from the left nostril (P < 0.001 vs P = 0.03). Cuff inflation maneuver also can be helpful in some cases. We did not need any operator change or Magill forceps for any of the patients.

Conclusion

Nasotracheal intubation via the right nostril can be safely and quickly performed with the Airtraq NT without the need of Magill forceps. We recommend the use of the 90° counterclockwise rotation, external laryngeal pressure, and head flexion maneuvers to direct the tube into the vocal cords first. On the other hand, cuff inflation maneuver must also be kept in mind.

Videolaryngoscopy versus direct laryngoscopy for nasotracheal intubation: A systematic review and meta-analysis of randomised controlled trials

STUDY OBJECTIVE

Nasotracheal intubation (NTI) is a common practice in the oral and maxillofacial surgeries. A systematic review and meta-analysis was performed to determine whether videolaryngoscopy (VL) compared with direct laryngoscopy (DL) can lead to better outcomes for NTI in adult surgical patients.

MEASUREMENTS

Only randomised controlled trials comparing VL and DL for NTI were included. The primary outcome was overall success rate and the second outcomes were first-attempt success rate, intubation time, rate of Cormack and Lehane classification 1, rate of Magill Forceps used, rate of postoperative sore throat, and ease of intubation.

MAIN RESULTS

Fourteen studies with 20 comparisons (n = 1052) were included in quantitative synthesis. The overall success rate was similar between two groups (RR, 1.03; p = 0.14; moderate-quality evidence). VL was associated with a higher first-attempt success rate (RR 1.09; p = 0.04; low-quality evidence), a shorten intubation time (MD-6.72 s; p = 0.0001; low-quality evidence), a higher rate of Cormack and Lehane classification 1 (RR, 2.11; p < 0.01; high-quality evidence), a less use of the Magill forceps (RR, 0.11; p < 0.01; high-quality evidence) and a lower incidence of postoperative sore throat (RR, 0.50; p = 0.03; high-quality evidence). Subgroup analysis based on whether with a difficult airway showed higher overall success (p < 0.01) and first-attempt success rates with VL (p = 0.04) in patients with difficult airways; however, these benefits was not shown in patients with a normal airway (p > 0.05); Subgroup analysis based on operators' experience showed that success rate did not differ between groups (p > 0.05), but intubation time was shortened by more than 50s by non-experienced operators (p < 0.05). Subgroup analysis based on different devices used showed that only non-integrated VL led to a shorter intubation time (p < 0.05).

CONCLUSIONS

The use of VL does not increase the overall success rate of NTI in adult patients with general anesthesia, but it improves the first-attempt success rate and laryngeal visualization, and shortens the intubation time. VL is particularly beneficial for patients with difficult airways.

The GlideScope with modified Magill forceps facilitates nasogastric tube insertion in anesthetized patients: A randomized clinical study

Objective

Insertion of a nasogastric tube (NGT) in patients who have been intubated with an endotracheal tube while under general anesthesia can cause difficulties and lead to complications, including hemorrhage. A visualization-aided modality was recently used to facilitate NGT insertion. Some studies have focused on the role of modified Magill forceps, which have angles similar to those of the GlideScope blade (Verathon, Bothell, WA, USA).

Methods

Seventy patients were divided into a control group (Group C) and an experimental group (GlideScope and modified Magill forceps, Group M).

Results

The total NGT insertion time was significantly shorter in Group M than C (71.3 ± 22.6 vs. 96.7 ± 57.5 s; mean difference, –25.3 s; 95% confidence interval [CI], 20.8–71.5). There were also significantly fewer mean insertion attempts in Group M than C (1.0 ± 0.0 vs. 2.11 ± 0.93). The success rate for the first attempt in Group C was 37.1%, while that in Group M was 100% (relative risk, 2.7; 95% CI, 1.7–4.1).

Conclusion

The use of the GlideScope with modified Magill forceps for insertion of an NGT in patients who are already intubated and under general anesthesia will shorten the insertion time and improve the success rate.

A randomized controlled trial comparing C Mac D Blade and Macintosh laryngoscope for nasotracheal intubation in patients undergoing surgeries for head and neck cancer

Purpose

Several devices are available to take care of difficult airway, but C-MAC D-Blade has scant evidence of its use in nasotracheal intubation in a difficult airway scenario.

Aims and Objectives

We compared the C-MAC D-Blade videolaryngoscope^™, and the standard Macintosh laryngoscope for nasal intubation in patients with difficult airways selected by El-Ganzouri risk index using parameters of time and attempts required for intubation, glottic view in terms of Cormack-Lehane grade, ease of intubation, success rate, use of accessory maneuvers, incidence of complications, and hemodynamic changes.

Methods

One hundred American Society of Anesthesiologists (ASA) I-III patients aged 20-70 years with EGRI score 1-≤7 scheduled for head and neck surgery requiring nasal intubation. ASA IV patients, patients with mouth opening <2.5 cm, patients difficult to mask ventilate, and patients with hyperkalemia and history of malignant hyperthermia were excluded from the study. Primary outcome was time taken to intubation, and secondary outcomes were a number of attempts, glottic view in terms of C/L grade, use of accessory maneuvers, success rate, incidence of trauma, ease of intubation, and hemodynamic changes before and after intubation.

Results

Time required for intubation was less (39.56 ± 15.65 s) in Group C than in Group M (50.34 ± 15.65 s). Cormack-Lehane Grade I and II view were more in C-MAC D-Blade group (P < 0.05). Success rate and ease of intubation were found to be more in C-MAC D-Blade group than in Macintosh group (P < 0.05). A number of attempts and incidence of complications such as trauma, bleeding, and failed intubation were greater in Macintosh group than in C-MAC D-Blade group. Hemodynamic changes were observed to be comparable in both the groups.

Conclusion

C-MAC D-Blade videolaryngoscope^™ is a better tool in anesthetic management of difficult airway for nasal intubation compared to conventional Macintosh laryngoscope.

Videolaryngoscopy versus direct laryngoscopy for adult patients requiring tracheal intubation

BACKGROUND

Successful tracheal intubation during general anaesthesia traditionally requires a line of sight to the larynx attained by positioning the head and neck and using a laryngoscope to retract the tongue and soft tissues of the floor of the mouth. Difficulties with intubation commonly arise, and alternative laryngoscopes that use digital and/or fibreoptic technology have been designed to improve visibility when airway difficulty is predicted or encountered. Among these devices, a rigid videolaryngoscope (VLS) uses a blade to retract the soft tissues and transmits a lighted video image to a screen.

OBJECTIVES

Our primary objective was to assess whether use of videolaryngoscopy for tracheal intubation in adults requiring general anaesthesia reduces risks of complications and failure compared with direct laryngoscopy. Our secondary aim was to assess the benefits and risks of these devices in selected population groups, such as adults with obesity and those with a known or predicted difficult airway.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase on 10 February 2015. Our search terms were relevant to the review question and were not limited by outcomes. We carried out clinical trials register searches and forward and backward citation tracking. We reran the search on 12 January 2016; we added potential new studies of interest from the 2016 search to a list of 'Studies awaiting classification', and we will incorporate these studies into the formal review during the review update.

SELECTION CRITERIA

We considered all randomized controlled trials and quasi-randomized studies with adult patients undergoing laryngoscopy performed with a VLS or a Macintosh laryngoscope in a clinical, emergency or out-of-hospital setting. We included parallel and cross-over study designs.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data, consulting a third review author to resolve disagreements. We used standard Cochrane methodological procedures, including assessment of risk of bias.

MAIN RESULTS

We included 64 studies identified during the 2015 search that enrolled 7044 adult participants and compared a VLS of one or more designs with a Macintosh laryngoscope. We identified 38 studies awaiting classification and seven ongoing studies. Of the 64 included studies, 61 included elective surgical patients, and three were conducted in an emergency setting. Among 48 studies that included participants without a predicted difficult airway, 15 used techniques to simulate a difficult airway. Seven recruited participants with a known or predicted difficult airway, and the remaining studies did not specify or included both predicted and not predicted difficult airways. Only two studies specifically recruited obese participants. It was not possible to blind the intubator to the device, and we noted a high level of inevitable heterogeneity, given the large number of studies.Statistically significantly fewer failed intubations were reported when a VLS was used (Mantel-Haenszel (M-H) odds ratio (OR), random-effects 0.35, 95% confidence Interval (CI) 0.19 to 0.65; 38 studies; 4127 participants), and fewer failed intubations occurred when a VLS was used in participants with an anticipated difficult airway (M-H OR, random-effects 0.28, 95% CI 0.15 to 0.55; six studies; 830 participants). We graded the quality of this evidence as moderate on the basis of the GRADE system. Failed intubations were fewer when a VLS was used in participants with a simulated difficult airway (M-H OR, random-effects 0.18, 95% CI 0.04 to 0.77; nine studies; 810 participants), but groups with no predicted difficult airway provided no significant results (M-H OR, random-effects 0.61, 95% CI 0.22 to 1.67; 19 studies; 1743 participants).Eight studies reported on hypoxia, and only three of these described any events; results showed no differences between devices for this outcome (M-H OR, random-effects 0.39, 95% CI 0.10 to 1.44; 1319 participants). Similarly, few studies reported on mortality, noting no differences between devices (M-H OR, fixed-effect 1.09, 95% CI 0.65 to 1.82; two studies; 663 participants), and only one study reporting on the occurrence of respiratory complications (78 participants); we graded these three outcomes as very low quality owing to lack of data. We found no statistically significant differences between devices in the proportion of successful first attempts (M-H OR, random-effects 1.27, 95% CI 0.77 to 2.09; 36 studies; 4731 participants) nor in those needing more than one attempt. We graded the quality of this evidence as moderate. Studies reported no statistically significant differences in the incidence of sore throat in the postanaesthesia care unit (PACU) (M-H OR, random-effects 1.00 (95% CI 0.73 to 1.38); 10 studies; 1548 participants) nor at 24 hours postoperatively (M-H OR random-effects 0.54, 95% CI 0.27 to 1.07; eight studies; 844 participants); we graded the quality of this evidence as moderate. Data combined to include studies of cross-over design revealed statistically significantly fewer laryngeal or airway traumas (M-H OR, random-effects 0.68, 95% CI 0.48 to 0.96; 29 studies; 3110 participants) and fewer incidences of postoperative hoarseness (M-H OR, fixed-effect 0.57, 95% CI 0.36 to 0.88; six studies; 527 participants) when a VLS was used. A greater number of laryngoscopies performed with a VLS achieved a view of most of the glottis (M-H OR, random-effects 6.77, 95% CI 4.17 to 10.98; 22 studies; 2240 participants), fewer laryngoscopies performed with a VLS achieved no view of the glottis (M-H OR, random-effects 0.18, 95% CI 0.13 to 0.27; 22 studies; 2240 participants) and the VLS was easier to use (M-H OR, random-effects 7.13, 95% CI 3.12 to 16.31; seven studies; 568 participants).Although a large number of studies reported time required for tracheal intubation (55 studies; 6249 participants), we did not present an effects estimate for this outcome owing to the extremely high level of statistical heterogeneity (I2 = 96%).

AUTHORS' CONCLUSIONS

Videolaryngoscopes may reduce the number of failed intubations, particularly among patients presenting with a difficult airway. They improve the glottic view and may reduce laryngeal/airway trauma. Currently, no evidence indicates that use of a VLS reduces the number of intubation attempts or the incidence of hypoxia or respiratory complications, and no evidence indicates that use of a VLS affects time required for intubation.

Continuous right thoracic paravertebral block following bolus initiation reduced postoperative pain after right-lobe hepatectomy: a randomized, double-blind, placebo-controlled trial

Background and Objectives

We hypothesized that continuous right thoracic paravertebral block, following bolus initiation, decreases opioid consumption after right-lobe hepatectomy in patients receiving patient-controlled intravenous analgesia with sufentanil.

Methods

Patients undergoing right-lobe hepatectomy with a right thoracic paravertebral catheter placed at T7 30 minutes before surgery were randomly assigned to receive through this catheter either a 10-mL bolus of 0.2% ropivacaine before emergence, followed by a continuous infusion of 6 mL/h for 24 hours (PVB group), or saline at the same scheme of administration (control group). All patients were started on patient-controlled intravenous analgesia with sufentanil in the postanesthesia care unit. The primary outcome measure was total sufentanil consumption during the first 24 postoperative hours. P = 0.05 was considered as significant. For the multiple comparisons of data at 5 different time points, the P value for the 0.05 level of significance was adjusted to 0.01.

Results

Sixty-six patients were assessed for eligibility, and a PVB catheter was successfully placed for 48 patients. Data were analyzed on 22 patients in group PVB and 22 patients in the control group. The cumulative sufentanil consumption in the PVB group (54.3 ± 12.1 μg) at 24 postoperative hours was more than 20% less than that of the control group (68.1 ± 9.9 μg) (P < 0.001). There was also a significant difference in pain scores (numerical rating scale) between groups, where the PVB group had lower scores than did the control group at rest and with coughing for the first 24 hours (P < 0.001).

Conclusions

Continuous right thoracic paravertebral block, following bolus initiation, has an opioid-sparing effect on sufentanil patient-controlled intravenous analgesia for right-lobe hepatectomy patients and reduces numerical rating scale pain scores at rest and with coughing in the first 24 postoperative hours.

[A randomised crossover trial comparing the Airtraq(®) NT, McGrath(®) MAC and Macintosh laryngoscopes for nasotracheal intubation of simulated easy and difficult airways in a manikin]

OBJECTIVE

Several devices can aid nasotracheal intubation when managing difficult airways. The McGrath MAC and Airtraq NT were compared with a Macintosh laryngoscope when studying the performance of anaesthetists with different levels of experience, in a manikin model of easy or difficult airway scenarios.

METHODS

Sixty-three anaesthetists were recruited into a randomised trial in which each performed nasotracheal intubation with all laryngoscopes, in both scenarios. The main endpoint was intubation time. Additional endpoints included laryngoscopic view, intubation success, number of optimisation manoeuvres, audible dental clicks and the force applied to the upper airway.

RESULTS

Intubation time was significantly shorter using the McGrath MAC in both scenarios and using the Airtraq in the difficult scenario, when compared with the Macintosh laryngoscope. Both devices gave more Cormack and Lehane grade 1 or 2 views than the Macintosh in the difficult scenario (p<0.001). The McGrath MAC had the best first-attempt success rate (98.4% vs. 96.8% and 95.8%, p<0.001 for the Airtraq NT and Macintosh laryngoscopes respectively). The number of optimisation manoeuvres, audible dental clicks and subjective assessment of the degree of force applied were significantly lower for indirect laryngoscopes versus the Macintosh laryngoscope (p<0.001).

CONCLUSION

In a manikin, the Airtraq and the McGrath laryngoscopes appeared superior to the Macintosh laryngoscope when dealing with simulated airway scenarios. Both devices were associated with better views, intubation times and rates of success, especially in a simulated "difficult airway". Overall satisfaction was highest with the McGrath laryngoscope. Similar clinical studies are needed.

A randomised crossover trial comparing the Airtraq(®) NT, McGrath(®) MAC and Macintosh laryngoscopes for nasotracheal intubation of simulated easy and difficult airways in a manikin

OBJECTIVE

Several devices can aid nasotracheal intubation when managing difficult airways. The McGrath MAC and Airtraq NT were compared with a Macintosh laryngoscope when studying the performance of anaesthetists with different levels of experience, in a manikin model of easy or difficult airway scenarios.

METHODS

Sixty-three anaesthetists were recruited into a randomised trial in which each performed nasotracheal intubation with all laryngoscopes, in both scenarios. The main endpoint was intubation time. Additional endpoints included laryngoscopic view, intubation success, number of optimisation manoeuvres, audible dental clicks and the force applied to the upper airway.

RESULTS

Intubation time was significantly shorter using the McGrath MAC in both scenarios and using the Airtraq in the difficult scenario, when compared with the Macintosh laryngoscope. Both devices gave more Cormack and Lehane grade 1 or 2 views than the Macintosh in the difficult scenario (p<0.001). The McGrath MAC had the best first-attempt success rate (98.4% vs. 96.8% and 95.8%, p<0.001 for the Airtraq NT and Macintosh laryngoscopes respectively). The number of optimisation manoeuvres, audible dental clicks and subjective assessment of the degree of force applied were significantly lower for indirect laryngoscopes versus the Macintosh laryngoscope (p<0.001).

CONCLUSION

In a manikin, the Airtraq and the McGrath laryngoscopes appeared superior to the Macintosh laryngoscope when dealing with simulated airway scenarios. Both devices were associated with better views, intubation times and rates of success, especially in a simulated "difficult airway". Overall satisfaction was highest with the McGrath laryngoscope. Similar clinical studies are needed.

Awake endotracheal intubation in patients with severely restricted mouth opening- alternative devices to fiberscope: series of cases and literature review

Awake Fiberoptic Intubation (AFI) is a standard method of airway management in the case of anticipated difficult intubation. It is usually performed with the use of flexible fiberscopes. In this report we have described two methods in which alternative devices to the fiberscope were utilized for awake intubation in patients with severely restricted mouth opening scheduled for craniomaxillofacial surgery: TruView PCD and Levitan FPS. Information about the use of these devices in such conditions has not been previously published in the literature. Some of the possible advantages of these alternative methods for AFI result from the fact that they are easy to use, especially for anesthesiologists who are relatively inexperienced with fiberscope intubation procedures. Additionally, these alternatives are cheaper than fiberscopes and can be used for many AFI procedures.

Tracheal intubation in patients with odentogenous abscesses and reduced mouth opening

BACKGROUND

Odentogenous abscesses with involvement of the facial or cervical spaces can be life-threatening and often have to be drained under general anaesthesia. Trismus and swelling can make intubation with a Macintosh laryngoscope difficult or even impossible. However, indirect laryngoscopy has been successful when conventional direct laryngoscopy has failed. Therefore, we evaluated the efficacy of the Glidescope laryngoscope in patients with odentogenous abscesses and the improvement in mouth opening after neuromuscular block.

METHODS

After approval of the ethics committee, 100 patients with odentogenous abscesses were randomized to undergo tracheal intubation with the Glidescope or Macintosh laryngoscope. Success rate, visualization of the glottis, intubation duration, and need for supporting manoeuvres were evaluated.

RESULTS

Intubation with the Glidescope was always successful, while conventional intubation failed in 17 out of 50 patients (P<0.0001). In all patients in whom conventional tracheal intubation failed, a subsequent attempt with the Glidescope was successful. The view at the glottis (according to Cormack and Lehane; P<0.0001), intubation duration [34 s (CI 27-41) vs 67 s (CI 52-82), mean (95% confidence interval); P=0.0001], and need for supporting manoeuvres (P<0.0001) were significantly different. The inter-incisor distance improved overall with induction of anaesthesia from 2.0 cm (CI 1.8-2.2) to 2.6 cm (CI 2.3-2.9; P<0.0001) and was correlated with the duration of symptoms.

CONCLUSIONS

In patients with odentogenous abscesses, the use of a Glidescope laryngoscope was associated with significantly faster tracheal intubation, with a better view, fewer supporting manoeuvres, and a higher success rate than with a conventional laryngoscope. Improvement of the inter-incisor distance after induction of anaesthesia correlated with the duration of symptoms.

Nasotracheal intubation with three indirect laryngoscopes assisted by standard or modified Magill forceps

We assessed the effect of modifying standard Magill forceps on the laryngeal introduction of an Eschmann stylet during nasotracheal intubations with three indirect laryngoscopes (Airtraq™, C-MAC(®) or GlideScope(®)) in patients with predicted difficult intubation. We allocated 50 participants to each laryngoscope. The stylet was advanced by one forceps followed by the other (standard or modified), with each sequence allocated to 25/50 for each laryngoscope. There were no differences in rates of failed tracheal intubation with the allocated laryngoscopes: 6/50, 5/50 and 5/50, respectively. An Eschmann stylet was advanced into the trachea less often with the standard forceps (65% vs 93%, p < 0.0001). Mean (SD) time for stylet advancement was longer with the standard forceps, 38 (30) vs 19 (19) s, p < 0.0001. In conclusion, the modified Magill forceps facilitated nasotracheal intubation, independent of the type of indirect laryngoscope.