Airway Scope: early clinical experience in 405 patients

Videolaryngoscopy versus direct laryngoscopy for tracheal intubation in neonates

BACKGROUND

Establishment of a secure airway is a critical part of neonatal resuscitation in the delivery room and the neonatal intensive care unit. Videolaryngoscopy has the potential to facilitate successful endotracheal intubation, and decrease adverse consequences of a delay in airway stabilization. Videolaryngoscopy may enhance visualization of the glottis and intubation success in neonates. This is an update of a review first published in 2015, and updated in 2018.

OBJECTIVES

To determine the effectiveness and safety of videolaryngoscopy compared to direct laryngoscopy in decreasing the time and attempts required for endotracheal intubation and increasing the success rate on first intubation attempt in neonates (0 to 28 days of age).

SEARCH METHODS

In November 2022, we updated the search for trials evaluating videolaryngoscopy for neonatal endotracheal intubation in CENTRAL, MEDLINE, Embase, CINAHL, and BIOSIS. We also searched abstracts of the Pediatric Academic Societies, clinical trials registries (www.

CLINICALTRIALS

gov; www.controlled-trials.com), and reference lists of relevant studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs), quasi-RCTs, cluster-RCTs, or cross-over trials, in neonates (0 to 28 days of age), evaluating videolaryngoscopy with any device used for endotracheal intubation compared with direct laryngoscopy.

DATA COLLECTION AND ANALYSIS

Three review authors performed data collection and analysis, as recommended by Cochrane Neonatal. Two review authors independently assessed studies identified by the search strategy for inclusion. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

The updated search yielded 7786 references, from which we identified five additional RCTs for inclusion, seven ongoing trials, and five studies awaiting classification. Three studies were included in the previous version of the review. For this update, we included eight studies, which provided data on 759 intubation attempts in neonates. We included neonates of either sex, who were undergoing endotracheal intubation in international hospitals. Different videolaryngoscopy devices (including C-MAC, Airtraq, and Glidescope) were used in the studies. For the primary outcomes; videolaryngoscopy may not reduce the time required for successful intubation when compared with direct laryngoscopy (mean difference [MD] 0.74, 95% confidence interval [CI] -0.19 to 1.67; 5 studies; 505 intubations; low-certainty evidence). Videolaryngoscopy may result in fewer intubation attempts (MD -0.08, 95% CI -0.15 to 0.00; 6 studies; 659 intubations; low-certainty evidence). Videolaryngoscopy may increase the success of intubation at the first attempt (risk ratio [RR] 1.24, 95% CI 1.13 to 1.37; risk difference [RD] 0.14, 95% CI 0.08 to 0.20; number needed to treat for an additional beneficial outcome [NNTB] 7, 95% CI 5 to 13; 8 studies; 759 intubation attempts; low-certainty evidence).  For the secondary outcomes; the evidence is very uncertain about the effect of videolaryngoscopy on desaturation or bradycardia episodes, or both, during intubation (RR 0.94, 95% CI 0.38 to 2.30; 3 studies; 343 intubations; very-low certainty evidence). Videolaryngoscopy may result in little to no difference in the lowest oxygen saturations during intubation compared with direct laryngoscopy (MD -0.76, 95% CI -5.74 to 4.23; 2 studies; 359 intubations; low-certainty evidence). Videolaryngoscopy likely results in a slight reduction in the incidence of airway trauma during intubation attempts compared with direct laryngoscopy (RR 0.21, 95% CI 0.05 to 0.79; RD -0.04, 95% CI -0.07 to -0.01; NNTB 25, 95% CI 14 to 100; 5 studies; 467 intubations; moderate-certainty evidence). There were no data available on other adverse effects of videolaryngoscopy. We found a high risk of bias in areas of allocation concealment and performance bias in the included studies.

AUTHORS' CONCLUSIONS

Videolaryngoscopy may increase the success of intubation on the first attempt and may result in fewer intubation attempts, but may not reduce the time required for successful intubation (low-certainty evidence). Videolaryngoscopy likely results in a reduced incidence of airway-related adverse effects (moderate-certainty evidence). These results suggest that videolaryngoscopy may be more effective and potentially reduce harm when compared to direct laryngoscopy for endotracheal intubation in neonates. Well-designed, adequately powered RCTS are necessary to confirm the efficacy and safety of videolaryngoscopy in neonatal intubation.

Comparison of McGrath, Pentax, and Macintosh laryngoscope in normal and cervical immobilized manikin by novices: a randomized crossover trial

BACKGROUND

The aim of this study was to compare tracheal intubation performance regarding the time to intubation, glottic view, difficulty, and dental click, by novices using McGrath videolaryngoscope (VL), Pentax Airway Scope (AWS) and Macintosh laryngoscope in normal and cervical immobilized manikin models.

METHODS

Thirty-five anesthesia nurses without previous intubation experience were recruited. Participants performed endotracheal intubation in a manikin model at two simulated neck positions (normal and fixed neck via cervical immobilization), using three different devices three times each. Performance parameters included intubation time, success rate of intubation, Cormack Lehane laryngoscope grading, dental click, and subjective difficulty score.

RESULTS

Intubation time and success rate during first attempt were not significantly different between the 3 groups in normal airway manikin. In the cervical immobilized manikin, the intubation time was shorter (p = 0.012), and the success rate with the first attempt was significantly higher (p < 0.001) when using McGrath VL and Pentax AWS compared with Macintosh laryngoscope. Both VLs showed less difficulty score (p < 0.001) and more Cormack Lehane grade I (p < 0.001) in both scenarios. The incidence of dental clicks was higher with Macintosh laryngoscope compared with McGrath VL in cervical immobilized airway (p < 0.001).

CONCLUSIONS

McGrath VL and Pentax AWS did not show clinically significant decrease in intubation time, however, they achieved higher first attempt success rate, easier intubation and better glottis view compared with Macintosh laryngoscope by novices in a cervical immobilized manikin model. McGrath VL may reduce the risk of dental injury compared with Macintosh laryngoscope in cervical immobilized scenario.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03161730), May 22, 2017 https://clinicaltrials.gov/ct2/hom.

Comparison of Pentax Airway Scope and Macintosh laryngoscope for orotracheal intubation in children: A randomised non-inferiority trial

BACKGROUND

Pentax Airway Scope (AWS) is a recently developed videolaryngoscope for use in both normal and difficult airways, yet its use in paediatric patients has not been established. The purpose of this study was to evaluate the efficacy of the Pentax AWS regarding intubation time, laryngeal view and ease of intubation in paediatric patients with normal airway, compared to Macintosh laryngoscope.

METHOD

A total of 136 paediatric patients aged 1-10 with American Society of Anaesthesiologists physical status I or II undergoing general anaesthesia were randomly allocated into two groups: Macintosh laryngoscope (n = 68) and Pentax Airway Scope (n = 68). Primary outcome was intubation time. Cormack-Lehane laryngeal view grade, application of optimal laryngeal external manipulation, intubation difficulty scale, intubation failure rate and adverse events were also measured.

RESULT

No significant difference was observed between the two groups regarding intubation time (P = 0.713). As for the laryngeal view grade, the Pentax group resulted in lower graded cases compared to the Macintosh group (P = 0.000). No optimal laryngeal external manipulation application was required in the Pentax group. Intubation difficulty scale resulted in lower values for Pentax group (P = 0.001). Failure rate was not different between the two groups (P = 0.619). There were significantly more teeth injury cases in the Pentax group than Macintosh group (P = 0.042).

CONCLUSION

Pentax Airway Scope provided similar intubation time and success rate, while improving laryngeal view, compared to Macintosh laryngoscopy in children with normal airway. When using Pentax AWS in children, however, the risk of teeth injury may increase.

Comparison of the paediatric blade of the Pentax-AWS and Ovassapian airway in fibreoptic tracheal intubation in patients with limited mouth opening and cervical spine immobilization by a semi-rigid neck collar: a randomized controlled trial

Background

We compared the performances of the paediatric blade of a Pentax Airway Scope and an Ovassapian airway in fibreoptic tracheal intubation in patients whose necks were stabilized by semi-rigid neck collars.

Methods

Ninety patients were enrolled in this prospective, open-label, randomized controlled trial. Patients were randomly allocated to one of two groups (Group OVA-FOB and Group AWS-FOB). The time to tracheal intubation, success rate of tracheal intubation, number of optimization manoeuvres (jaw thrust), and difficulty of manipulation of the fibreoptic bronchoscope were compared between the groups.

Results

The time to tracheal intubation was significantly shorter (32 vs 50 s; median difference 19 s; 95% confidence interval 14-25 s; P<0.001) and manipulation of the fibreoptic bronchoscope was significantly easier for Group AWS-FOB. Optimization manoeuvres were rarely required to facilitate fibreoptic tracheal intubation in Group AWS-FOB [jaw thrust, 0 (0%); jaw thrust with anterior neck collar removal, 1 (2%)] compared with that required in Group OVA-FOB [jaw thrust, 39 (87%); jaw thrust with anterior neck collar removal, 2 (4%)]. There was no significant difference in the success rate of tracheal intubation on the first attempt between groups [Group AWS-FOB, 45 (100%); Group OVA-FOB, 44 (98%)].

Conclusions

Combined use of the paediatric blade of a Pentax Airway Scope and a fibreoptic bronchoscope enabled rapid tracheal intubation, minimizing the use of external manoeuvres of the airway, in patients with limited mouth opening and cervical spine immobilization by semi-rigid neck collars, compared with use of the Ovassapian airway and the fibreoptic bronchoscope.

Clinical trial registration

NCT02827110.

Videolaryngoscopy versus direct laryngoscopy for tracheal intubation in neonates

BACKGROUND

Establishment of a secure airway is a critical part of neonatal resuscitation in the delivery room and the neonatal unit. Videolaryngoscopy has the potential to facilitate successful endotracheal intubation and decrease adverse consequences of delay in airway stabilization. Videolaryngoscopy may enhance visualization of the glottis and intubation success in neonates.

OBJECTIVES

To determine the efficacy and safety of videolaryngoscopy compared to direct laryngoscopy in decreasing the time and attempts required for endotracheal intubation and increasing the success rate at first intubation in neonates.

SEARCH METHODS

We used the search strategy of Cochrane Neonatal. In May 2017, we searched for randomized controlled trials (RCT) evaluating videolaryngoscopy for neonatal endotracheal intubation in Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, abstracts of the Pediatric Academic Societies, websites for registered trials at www.clinicaltrials.gov and www.controlled-trials.com, and reference lists of relevant studies.

SELECTION CRITERIA

RCTs or quasi-RCTs in neonates evaluating videolaryngoscopy for endotracheal intubation compared with direct laryngoscopy.

DATA COLLECTION AND ANALYSIS

Review authors performed data collection and analysis as recommended by Cochrane Neonatal. Two review authors independently assessed studies identified by the search strategy for inclusion.We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

The search yielded 7057 references of which we identified three RCTs for inclusion, four ongoing trials and one study awaiting classification. All three included RCTs compared videolaryngoscopy with direct laryngoscopy during intubation attempts by trainees.Time to intubation was similar between videolaryngoscopy and direct laryngoscopy (mean difference (MD) -0.62, 95% confidence interval (CI) -6.50 to 5.26; 2 studies; 311 intubations) (very low quality evidence). Videolaryngoscopy did not decrease the number of intubation attempts (MD -0.05, 95% CI -0.18 to 0.07; 2 studies; 427 intubations) (very low quality evidence). Moderate quality evidence suggested that videolaryngoscopy increased the success of intubation at first attempt (typical risk ratio (RR) 1.44, 95% CI 1.20 to 1.73; typical risk difference (RD) 0.19, 95% CI 0.10 to 0.28; number needed to treat for an additional beneficial outcome (NNTB) 5, 95% CI 4 to 10; 3 studies; 467 intubation attempts).Desaturation episodes during intubation attempts were similar between videolaryngoscopy and direct laryngoscopy (MD -0.76, 95% CI -5.74 to 4.23; 2 studies; 359 intubations) (low quality evidence). There was no difference in the incidence of airway trauma due to intubation attempts (RR 0.10, 95% CI 0.01 to 1.80; RD -0.04, 95% CI -0.09 to -0.00; 1 study; 213 intubations) (low quality evidence).There were no data available on other adverse effects of videolaryngoscopy.

AUTHORS' CONCLUSIONS

Moderate to very low quality evidence suggests that videolaryngoscopy increases the success of intubation in the first attempt but does not decrease the time to intubation or the number of attempts for intubation. However, these studies were conducted with trainees performing the intubations and these results highlight the potential usefulness of the videolaryngoscopy as a teaching tool. Well-designed, adequately powered RCTs are necessary to confirm efficacy and address safety and cost-effectiveness of videolaryngoscopy for endotracheal intubation in neonates by trainees and those proficient in direct laryngoscopy.

Videolaryngoscopy versus direct laryngoscopy for tracheal intubation in neonates

BACKGROUND

Establishment of secure airway is a critical part of neonatal resuscitation both in the delivery room and in the neonatal unit. Videolaryngoscopy is a new technique that has the potential to facilitate successful endotracheal intubation and decrease adverse consequences of delay in airway stabilization. Videolaryngoscopy may enhance visualization of the glottis and intubation success in neonates.

OBJECTIVES

To determine the efficacy and safety of videolaryngoscopy compared to direct laryngoscopy in decreasing the time and attempts required and increasing the success rate for endotracheal intubation in neonates.

SEARCH METHODS

We used the search strategy of the Cochrane Neonatal Review Group. We searched for randomized controlled trials evaluating videolaryngoscopy for neonatal endotracheal intubation in May 2013 in the electronic databases; the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; CINAHL; abstracts of the Pediatric Academic Societies; websites for registered trials at www.clinicaltrials.gov and www.controlled-trials.com; and in the reference lists of relevant studies.

SELECTION CRITERIA

Randomized or quasi-randomized trials in neonates evaluating videolaryngoscopy for endotracheal intubation compared with direct laryngoscopy.

DATA COLLECTION AND ANALYSIS

Review authors performed data collection and analysis as recommended by the Cochrane Neonatal Review Group. Two review authors (KL and MP) independently assessed studies identified by the search strategy for inclusion.

MAIN RESULTS

Our search strategy performed in May 2013 yielded 7057 references. Two review authors (MP and KL) independently assessed all references for inclusion. We did not find any completed studies for inclusion but identified three ongoing trials and one study awaiting classification.

AUTHORS' CONCLUSIONS

There was insufficient evidence to recommend or refute the use of videolaryngoscopy for endotracheal intubation in neonates. Well-designed, adequately powered randomized controlled studies are necessary to address efficacy and safety of videolaryngoscopy for endotracheal intubation in neonates.

Influence of clinical experience of the Macintosh laryngoscope on performance with the Pentax-AWS Airway Scope(®), a rigid video-laryngoscope, by paramedics in Japan

PURPOSE

We sought to establish the clinical utility of the Pentax-AWS Airway Scope(®) (AWS) when used by paramedics to intubate the trachea, and to evaluate whether their performance was influenced by previous clinical experience with the Macintosh laryngoscope (ML).

METHODS

Twenty paramedics attempted tracheal intubation using the AWS in five patients each in the operating room. We recorded the success rate, the number of intubation attempts, and the time for intubation and adverse events, and compared these based on the paramedics' previous clinical experience with the ML. Ten paramedics had no prior clinical experience of the ML (group A) and 10 had used it on more than 30 occasions (group B).

RESULTS

The intubation success rate was 99 % (99/100). Notably, 96 % (47/49) of intubations were achieved on the first attempt by the inexperienced paramedics in group A, compared with 64 % (32/50) by the experienced paramedics in group B (p = 0.0001). The time to intubation (mean ± SD) was significantly shorter in group A than in group B (37 ± 24 vs. 48 ± 21 s, p = 0.002). There were marked variations in the times taken to intubate, but no apparent improvement as the intubators gained experience between their first and fifth cases. No complications were encountered in either group.

CONCLUSION

We found that paramedics could achieve a high tracheal intubation success rate using the AWS independent of previous airway management experience. Better intubation performance with the AWS was observed in paramedics without clinical experience with the ML.

Awake tracheal intubation using Pentax airway scope in 30 patients: A Case series

BACKGROUND AND AIMS

Pentax airway scope (AWS) has been successfully used for managing difficult intubations. In this case series, we aimed to evaluate the success rate and time taken to complete intubation, when AWS was used for awake tracheal intubation.

METHODS

We prospectively evaluated the use of AWS for awake tracheal intubation in 30 patients. Indication for awake intubation, intubation time, total time to complete tracheal intubation, laryngoscopic view (Cormack and Lehane grade), total dose of local anaesthetic used, anaesthetists rating and patient's tolerance of the procedure were recorded.

RESULTS

The procedure was successful in 25 out of the 30 patients (83%). The mean (standard deviation) intubation time and total time to complete the tracheal intubation was 5.4 (2.4) and 13.9 (3.7) min, respectively in successful cases. The laryngeal view was grade 1 in 24 and grade 2 in one of 25 successful intubations. In three out of the five patients where the AWS failed, awake tracheal intubation was successfully completed with the assistance of flexible fibre optic scope (FOS).

CONCLUSION

Awake tracheal intubation using AWS was successful in 83% of patients. Success rate can be further improved using a combination of AWS and FOS. Anaesthesiologists who do not routinely use FOS may find AWS easier to use for awake tracheal intubation using an oral route.

Pentax Airway Scope® vs Macintosh laryngoscope for tracheal intubation in adult patients: a systematic review and meta-analysis

The Pentax Airway Scope(®) is a single-use optical videolaryngoscope designed to assist with difficult tracheal intubation. We systematically reviewed the efficacy of the Pentax Airway Scope with that of a conventional laryngoscope for tracheal intubation in adults with 'normal' and 'difficult' airways. We included 17 randomised controlled trials with a total of 1801 participants. We used the DerSimonian and Laird random-effects model to calculate pooled relative risk or weighted mean differences. The relative risk (95% CI) of a Cormack-Lehane grade-1 laryngeal view was 2.40 (1.76-2.49) with the Pentax Airway Scope compared with the Macintosh laryngoscope, p < 0.00001. We found no other differences between the two laryngoscopes. Despite a superior laryngeal view, the Pentax Airway Scope provides little clinical benefit over the conventional laryngoscope.

Incidence and predictors of difficult nasotracheal intubation with airway scope

Purpose

The airway scope (AWS) improves views of the larynx during orotracheal intubation. However, the role of the AWS in routine nasotracheal intubation has not been studied adequately.

Methods

One hundred and three patients undergoing dental and maxillofacial surgery that required general anesthesia and nasotracheal intubation were enrolled. The study was approved by our Institution Review Board, and written informed consent was obtained from all patients. We evaluated the success rate of AWS intubation and the incidence of difficult nasotracheal intubation using a modified intubation difficulty scale (IDS) to examine preoperative characteristics and intubation profiles. Categories were difficult intubation (IDS ≥5), mildly difficult (IDS = 1–4), and intubation without difficulty (IDS = 0). We also assessed the incidence of the use of Magill forceps or cuff inflation (the cuff of endotracheal tube is inflated with 10–15 ml air) to guide the endotracheal tube into the glottis.

Results

AWS nasotracheal intubation was 100 % successful. The cuff inflation technique was used in 37 patients. Neither Magill forceps nor other devices were needed for any patient during AWS use. The incidence of difficult nasotracheal intubation was 10 % (n = 10). Of the patients, 61 % (n = 63) had mildly difficult intubation and 29 % (n = 30) had no difficulty. Patients with difficult intubation were more likely to be male and to have a larger tongue and a higher Cormack grade than in the other two groups. Complications, involving minor soft tissue injury, were observed in only 1 patient (1 %).

Conclusion

The AWS achieves a high success rate for nasotracheal intubation with cuff inflation in patients undergoing dental and maxillofacial surgery.

The difficult airway with recommendations for management--part 1--difficult tracheal intubation encountered in an unconscious/induced patient

Background

Previously active in the mid-1990s, the Canadian Airway Focus Group (CAFG) studied the unanticipated difficult airway and made recommendations on management in a 1998 publication. The CAFG has since reconvened to examine more recent scientific literature on airway management. The Focus Group’s mandate for this article was to arrive at updated practice recommendations for management of the unconscious/induced patient in whom difficult or failed tracheal intubation is encountered.

Methods

Nineteen clinicians with backgrounds in anesthesia, emergency medicine, and intensive care joined this iteration of the CAFG. Each member was assigned topics and conducted reviews of Medline, EMBASE, and Cochrane databases. Results were presented and discussed during multiple teleconferences and two face-to-face meetings. When appropriate, evidence- or consensus-based recommendations were made together with assigned levels of evidence modelled after previously published criteria.

Conclusions

The clinician must be aware of the potential for harm to the patient that can occur with multiple attempts at tracheal intubation. This likelihood can be minimized by moving early from an unsuccessful primary intubation technique to an alternative “Plan B” technique if oxygenation by face mask or ventilation using a supraglottic device is non-problematic. Irrespective of the technique(s) used, failure to achieve successful tracheal intubation in a maximum of three attempts defines failed tracheal intubation and signals the need to engage an exit strategy. Failure to oxygenate by face mask or supraglottic device ventilation occurring in conjunction with failed tracheal intubation defines a failed oxygenation, “cannot intubate, cannot oxygenate” situation. Cricothyrotomy must then be undertaken without delay, although if not already tried, an expedited and concurrent attempt can be made to place a supraglottic device.

A systematic review of the role of videolaryngoscopy in successful orotracheal intubation

BACKGROUND

The purpose of our study was to organize the literature regarding the efficacy of modern videolaryngoscopes in oral endotracheal intubation, then perform a quality assessment according to recommended external criteria and make recommendations for use.

METHODS

Inclusion criteria included devices with recent studies of human subjects. A total of 980 articles were returned in the initial search and 65 additional items were identified using cited references. After exclusion of articles failing to meet study criteria, 77 articles remained. Data were extracted according to the rate of successful intubation and improvement of glottic view compared with direct laryngoscopy. Studies were classified according to whether they primarily examined subjects with normal airways, possessing risk factors for difficult direct laryngoscopy, or following difficult or failed direct laryngoscopy.

RESULTS

The evidence of efficacy for videolaryngoscopy in the difficult airway is limited. What evidence exists is both randomized prospective and observational in nature, requiring a scheme that evaluates both forms and allows recommendations to be made.

CONCLUSIONS

In patients at higher risk of difficult laryngoscopy we recommend the use of the Airtraq, CTrach, GlideScope, Pentax AWS and V-MAC to achieve successful intubation. In difficult direct laryngoscopy (C&L >/= 3) we cautiously recommend the use of the Airtraq, Bonfils, Bullard, CTrach, GlideScope, and Pentax AWS, by an operator with reasonable prior experience, to achieve successful intubation when used in accordance with the ASA practice guidelines for management of the difficult airway. There is additional evidence to support the use of the Airtraq, Bonfils, CTrach, GlideScope, McGrath, and Pentax AWS following failed intubation via direct laryngoscopy to achieve successful intubation. Future investigation would benefit from precise qualification of the subjects under study, and an improvement in overall methodology to include randomization and blinding.

Observations on the assessment and optimal use of videolaryngoscopes

Due to the large number of videolaryngoscopes now available, it might be difficult for novice users to assess the various devices or use them optimally. We have collated the experiences of several airway management experts to assist in the assessment and optimal use of seven commonly used videolaryngoscopes. While all videolaryngoscopes have unique features, they can be broadly divided into those inserted via a midline approach over the tongue and those inserted laterally along the floor of the mouth. Videolaryngoscopes that are placed on the floor of the mouth displace the tongue antero-laterally and flatten the submandibular tissues. They generally require a conventional shaped bougie for tracheal intubation. Videolaryngoscopes that use the midline approach may have an in-built airway conduit for the tracheal tube or may require a 'J-shaped' stylet in the tracheal tube to negotiate the upper airway. This may cause difficulty when the tracheal tube is inserted through the glottis and the tip abuts the anterior wall of the subglottic space. Knowledge of the mechanism used by videolaryngoscopes to achieve laryngoscopy is essential for safe and successful tracheal intubation when using these devices.

Macintosh laryngoscope vs. Pentax-AWS video laryngoscope: comparison of efficacy and cardiovascular responses to tracheal intubation in major burn patients

BACKGROUND

Patients with major burns accompanied with airway edema need more attention for airway management. Although the Pentax-AWS has an advantage in managing endotracheal intubation more easily, its usefulness cannot be assured if it does not maintain hemodynamic stability in burn patients. The aim of this study was to compare cardiovascular responses and general efficacy of the Pentax-AWS and Macintosh laryngoscopes in burn patients.

METHODS

American Society of Anesthesiologists physical status 2 or 3 adult patients with major burn injury were randomly assigned to group P (AWS, n = 50) or group M (Macintosh, n = 50). Fifty-nine patients assigned to the Macintosh group and no patient to AWS group were excluded because of failure to first intubation. Hemodynamic data at baseline, just before and after intubation as well as 3, 5 and 10 minutes after intubation and grade of sore throat were recorded in two groups. Intubation time, success rate of intubation, number of intubation attempts and the percentage of glottic opening (POGO) scores were also observed and analyzed in all patients.

RESULTS

A statistically significant increase in heart rate just after laryngoscopy was seen in group M. The success rate of the first attempt in group P (100%) was greater than with the group M (46%). POGO scores were higher in group P (97 ± 4%) than in group M (48 ± 29%)

CONCLUSIONS

The use of Pentax-AWS offers a reduced degree of heart rate elevation compared with the Macintosh laryngoscope and better intubation environments in major burn patients.

Tracheal intubation using Airway Scope in two patients with difficult airway during cardiopulmonary resuscitation

The Airway Scope AWS-S100 (AWS, Pentax, Tokyo), a rigid video laryngoscope with integrated tube guidance that has recently become commercially available, helped the authors to establish airways in two patients with in-hospital cardiopulmonary arrest, after failed attempts to intubate the patients using the Macintosh laryngoscope (that only commanded the Cormack-Lehane grade 4 glottic views), the laryngeal mask airway, and even surgical cricothyroidotomy for the second case. This showed the utility of the AWS in the management of difficult airway cases even in emergency settings.

Validation of the Pentax-AWS Airwayscope utility as an intubation device during cardiopulmonary resuscitation on the ground

PURPOSE

The 2005 American Heart Association guidelines for cardiopulmonary resuscitation emphasize that all rescuers should minimize interruption of chest compressions even for endotracheal intubation. We previously reported that the utility of the Pentax-AWS Airwayscope (AWS) was superior to that of the Macintosh laryngoscope (McL) for securing airways during chest compression in "on the bed" simulated circumstances. However, because most cardiopulmonary arrest happens "on the ground" in the real world, we compared the utility of the McL and the AWS during chest compression on the ground and on the bed.

METHODS

Fourteen doctors training in the anesthesia department performed tracheal intubation on a manikin with the McL and the AWS in simulations "on the bed" and "on the ground".

RESULTS

In the McL trial, 6 participants failed on the bed, and 10 of them also failed on the ground during chest compression. In the AWS trial, all participants successfully secured the airway regardless of chest compression both on the bed and on the ground. With the AWS, intubation time was not lengthened because of chest compression either on the bed or on the ground. The AWS scored better than the McL on the visual analog scale in laryngoscopy and tube passage of the glottis both on the bed and on the ground.

CONCLUSION

We conclude that the AWS is an effective device for endotracheal intubation during chest compression not only on the bed but also on the ground.

Tracheal intubation of a difficult airway using Airway Scope, Airtraq, and Macintosh laryngoscope: a comparative manikin study of inexperienced personnel

BACKGROUND

The Airway Scope (AWS) (Pentax-AWS, Hoya Corp., Tokyo, Japan) and the Airtraq (ATQ) (Prodol, Vizcaya, Spain) have similarities in the novel structures of their blades. In this study, we evaluated the ease of use of the AWS and ATQ compared with the Macintosh laryngoscope (ML) by inexperienced personnel in a simulated manikin difficult airway.

METHODS

Twenty-four fifth-year medical students with no previous experience in tracheal intubation participated in this study. We used an advanced patient simulator (SimMan(R), Laerdal Medical, Stavanger, Norway) to simulate difficult airway scenarios including cervical spine rigidity, limited mouth opening, and pharyngeal obstruction. The sequences in selecting devices and scenarios were randomized. Success rates for tracheal intubation, and the time required for visualization of the glottis, tracheal intubation, and inflation of the lungs, and the number of optimization maneuvers and dental click sounds were analyzed. The 3 different intubation devices were tested in 4 different scenarios by 24 students.

RESULTS

Both the AWS and ATQ had very high success rates of tracheal intubation compared with the ML (AWS 100%*; ATQ 98%*; and ML 89%; *P < 0.05 AWS, ATQ versus ML). The time to intubation with the AWS was significantly shorter than with the ATQ and ML (AWS 11 +/- 6 seconds; ATQ 16 +/- 12 seconds; and ML 16 +/- 11 seconds; *P < 0.05 AWS versus ATQ, ML). The number of optimization maneuvers with the AWS was significantly lower than with the ATQ and ML. There were significantly more audible dental click sounds with the ML than with the AWS and ATQ.

CONCLUSION

Both the AWS and ATQ may be suitable devices for difficult intubation by inexperienced personnel in this manikin simulated scenario. Further studies in a clinical setting are necessary to confirm these findings.

Airway scope vs Macintosh laryngoscope during chest compressions on a fresh cadaver model

PURPOSES

This study compared the Airway scope (AWS) to the Macintosh laryngoscope (ML) during chest compressions on a fresh cadaver.

METHODS

This was a prospective crossover study. The participants who had experiences with AWS were excluded. The participants intubated with randomly assigned AWS or ML on a fresh cadaver during chest compressions. Primary outcome were as follows: time to intubation, ease of intubation (rated by using the visual analog scale [VAS]), and intubation success rate.

RESULTS

Twenty-five were enrolled. Median time of intubation was similar between the AWS and ML (AWS, 18.5 seconds vs ML, 18.3 seconds; P = .112). The median VAS of AWS and ML were 3.0 and 2.0, respectively (P = .023). There was no failure of intubation. However, participants replied that the AWS was more difficult to use than the ML.

CONCLUSION

Considering the lack of experience with the AWS, AWS could be an alternative intubation device during chest compressions after practices with AWS.

Comparison of Parker-tipped and Murphy-tipped tracheal tubes in Airway Scope-assisted intubation in a manikin

PURPOSE

We tested our hypothesis that a Parker-tipped tracheal tube could improve the reliability of tracheal tube passage as compared to a Murphy-tipped tracheal tube during Airway Scope-assisted intubation in a manikin.

METHODS

Twenty-seven resident doctors performed Airway Scope-assisted intubations using both tracheal tubes, and the number of times the tracheal tube tip touched the glottis or other laryngeal structures was counted on the Airway Scope monitor.

RESULTS

The incidence of the tracheal tube tip touching the glottis during Airway Scope-assisted intubation using the Parker-tipped tracheal tube (7.4%; 2 of 27 attempts) was significantly less than that obtained using the Murphy-tipped tracheal tube (33.3%; 9 of 27 attempts; P = 0.039).

CONCLUSION

When the advancement of a conventional tracheal tube during Airway Scope-assisted intubation is likely to result in collision with the glottis or other laryngeal structures, the selection of a Parker-tipped tracheal tube is a better option.

Video and optic laryngoscopy assisted tracheal intubation--the new era

With advances in technology, videoscopy and optic intubation have been gaining popularity particularly in patients with difficult airways or as rescue devices in failed intubation attempts. Their routine use is, however an uncommon occurrence. This review paper will summarise some of those newly developed devices currently available to assist tracheal intubation, their advantages, disadvantages when compared with the conventional laryngoscope and finally, evidence to support their use in both elective and emergency airway management.