Success rates and endotracheal tube insertion times of experienced emergency physicians using five video laryngoscopes: a randomised trial in a simulated trapped car accident victim

A comparison of tracheal intubation using intubrite laryngoscope and conventional MAC laryngoscope: An open, prospective, crossover manikin study

BACKGROUND

New devices are more available in the pre-hospital environment operational theaters and emergency departments. One is an intubrite laryngoscope (INT) with Dual LED lighting that combines ultraviolet and white LED. The study aimed to compare the efficacy of endotracheal intubation using INT and conventional laryngoscope performed by inexperienced paramedics (paramedics students) and paramedics with experience in advanced airways management in full and limited accessibility settings.

METHODS

It was an open, prospective, crossover manikin study. Sixty paramedics and paramedic students were recruited. Participants were divided into 2 equal groups depending on their experience (n = 30). Experienced participants were further randomly divided into 2 groups (n = 15). Inexperienced participants were also randomly divided into 2 groups (n = 15). The criterion of inexperience was 5 or fewer intubation by any laryngoscope. Inexperience participants were asked to perform tracheal intubation in standard pre-hospital settings (without limited access to manikin) (scenario A) and difficult pre-hospital settings (limited access to manikin - narrow space between benches) (scenario B). Experience participants were asked to intubate manikin in difficult pre-hospital settings.

RESULTS

In the normal pre-hospital environment, the success rate after the first attempt was 56,7% for conventional laryngoscope and 66,7% for intubrite. However, the overall effectiveness of tracheal intubation using both laryngoscopes in 3 attempts was 90% for both devices. The successful rate of first attempt intubation in a difficult environment by inexperienced was 73,3% for INT and 50% for conventional laryngoscope. Overall effectiveness was 83,3% and 86,7% respectively. The successful rate of first attempt intubation in the experienced group was 86,7% with INT compared to 60% with a conventional laryngoscope in difficult settings. Overall effectiveness was 96,7% for both devices.

CONCLUSION

Intubrite provided better working conditions and make up for deficiencies in successful tracheal intubation by inexperienced participants in a normal and difficult environment. Tracheal intubation with intubrite was more effective in the experienced group. Tracheal intubation effectiveness with intubrite was also higher in the experienced group.

Comparison of face-to-face tracheal intubation and conventional head-end tracheal intubation using Airtraq™ video-laryngoscope in adults - A randomised study

Background and Aims

Tracheal intubation can be difficult in certain scenarios where the head-end of the patient is not accessible as in entrapped casualties. A face-to-face technique using a video-laryngoscope can prove to be useful in such scenarios. However, the two positions of tracheal intubation namely, face-to-face and head-end, using video-laryngoscope have never been compared in patients.

Material and Methods

Fifty patients of either sex, between 18 and 60 years, ASA class I/II, MPC I/II, scheduled to undergo surgical operations requiring general anesthesia with tracheal intubation were randomly allocated to either Group F (face-to-face intubation) or Group H (head-end intubation). Intubation was performed using Airtraq™ video-laryngoscope in both groups. Time taken for successful intubation, device insertion time, glottic view as per Cormack and Lehane (CL) grade, ease, attempts, the incidence of failed intubation, and hemodynamic parameters were noted.

Results

The time taken for successful intubation in Group F was significantly longer than in Group H (38.09 ± 19.45 s vs. 19.32 ± 9.86 s, respectively; P < 0.001). Three cases of failed intubation were noted in Group F compared to none in Group H (P = 0.235). Glottic view, ease, attempts, and hemodynamic parameters were comparable among the groups (P > 0.05).

Conclusion

The time taken for successful tracheal intubation was longer in face-to-face technique than in head-end technique in patients with the normal airway. However, both techniques were similar in terms of glottic view, ease of intubation and number of intubation attempts, the incidence of failed intubation, and hemodynamic changes. Therefore, face-to-face tracheal intubation is a good alternative to secure the airway when the head-end is not accessible.

A comparison of face-to-face endotracheal intubation and standard intubation using Airtraq video laryngoscope in morbidly obese patients: A randomized controlled trial

BACKGROUND

Routine endotracheal intubation requires a patient in supine position with an operator standing behind the patient's head. In case of a morbidly obese patient positioned in the recommended semi-recumbent position, an alternative method can be considered. Face-to-face intubation can be used both in patients in sitting as well as in prone position and when there is difficult access to the head. Evaluation of effectiveness and safety of face-to-face intubation in morbidly obese adult patients with body mass index over 40 kg m-2.

METHODS

The study was approved by the Local Ethics Committee and written informed consent from patients was obtained. We conducted a parallel randomized controlled trial with patients scheduled for elective sleeve gastrectomy. The trial was registered in ClinicalTrials with a number NCT04959149. Randomization and allocation to trial groups were carried out using the envelope method. The primary outcomes were the time of intubation and the first pass success of endotracheal intubation.

RESULTS

76 patients (routine intubation n = 36, face-to-face intubation n = 40) were included in the study with no dropouts. The intubation success rates were 82.5% versus 100%, mean intubation time was 17.1 ± 18 seconds versus 29 ± 11 seconds and the need for additional maneuvers (backward, upward, rightward pressure or flexing the neck) was 15% versus 19.5%, in face-to-face and routine intubation, respectively. No injuries to teeth or mucosa have been reported. There were no incidents of desaturation below 92% or other complications associated with intubation.

CONCLUSION

Face-to-face intubation is shorter than the routine intubation in obese patients. This method may be an alternative to standard intubation in case of airway management in morbidly obese patients in semi-erect position; however, it requires both training and practice.

Using supraglottic airways by paramedics for airway management in analogue microgravity increases speed and success of ventilation

In the next few years, the number of long-term space missions will significantly increase. Providing safe concepts for emergencies including airway management will be a highly challenging task. The aim of the present trial is to compare different airway management devices in simulated microgravity using a free-floating underwater scenario. Five different devices for airway management [laryngeal mask (LM), laryngeal tube (LT), I-GEL, direct laryngoscopy (DL), and video laryngoscopy (VL)] were compared by n = 20 paramedics holding a diving certificate in a randomized cross-over setting both under free-floating conditions in a submerged setting (pool, microgravity) and on ground (normogravity). The primary endpoint was the successful placement of the airway device. The secondary endpoints were the number of attempts and the time to ventilation. A total of 20 paramedics (3 female, 17 male) participated in this study. Success rate was highest for LM and LT and was 100% both during simulated microgravity and normogravity followed by the I-GEL (90% during microgravity and 95% during normogravity). However, the success rate was less for both DL (60% vs. 95%) and VL (20% vs. 60%). Fastest ventilation was performed with the LT both in normogravity (13.7 ± 5.3 s; n = 20) and microgravity (19.5 ± 6.1 s; n = 20). For the comparison of normogravity and microgravity, time to ventilation was shorter for all devices on the ground (normogravity) as compared underwater (microgravity). In the present study, airway management with supraglottic airways and laryngoscopy was shown to be feasible. Concerning the success rate and time to ventilation, the optimum were supraglottic airways (LT, LM, I-GEL) as their placement was faster and associated with a higher success rate. For future space missions, the use of supraglottic airways for airway management seems to be more promising as compared to tracheal intubation by DL or VL.

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.

Comparing Four Video Laryngoscopes and One Optical Laryngoscope with a Standard Macintosh Blade in a Simulated Trapped Car Accident Victim

Background

Tracheal intubation still represents the “gold standard” in securing the airway of unconscious patients in the prehospital setting. Especially in cases of restricted access to the patient, video laryngoscopy became more and more relevant.

Objectives

The aim of the study was to evaluate the performance and intubation success of four different video laryngoscopes, one optical laryngoscope, and a Macintosh blade while intubating from two different positions in a mannequin trial with difficult access to the patient.

Methods

A mannequin with a cervical collar was placed on the driver's seat. Intubation was performed with six different laryngoscopes either through the driver's window or from the backseat. Success, C/L score, time to best view (TTBV), time to intubation (TTI), and number of attempts were measured. All participants were asked to rate their favored device.

Results

Forty-two physicians participated. 100% of all intubations performed from the backseat were successful. Intubation success through the driver's window was less successful. Only with the Airtraq® optical laryngoscope, 100% success was achieved. Best visualization (window C/L 2a; backseat C/L 2a) and shortest TTBV (window 4.7 s; backseat 4.1 s) were obtained when using the D-Blade video laryngoscope, but this was not associated with a higher success through the driver's window. Fastest TTI was achieved through the window (14.2 s) when using the C-MAC video laryngoscope and from the backseat (7.3 s) when using a Macintosh blade.

Conclusions

Video laryngoscopy revealed better results in visualization but was not associated with a higher success. Success depended on the approach and familiarity with the device. We believe that video laryngoscopy is suitable for securing airways in trapped accident victims. The decision for an optimal device is complicated and should be based upon experience and regular training with the device.

Videolaryngoscopy for Physician-Based, Prehospital Emergency Intubation: A Prospective, Randomized, Multicenter Comparison of Different Blade Types Using A.P. Advance, C-MAC System, and KingVision

BACKGROUND

Videolaryngoscopy is a valuable technique for endotracheal intubation. When used in the perioperative period, different videolaryngoscopes vary both in terms of technical use and intubation success rates. However, in the prehospital environment, the relative performance of different videolaryngoscopic systems is less well studied.

METHODS

We conducted this prospective, randomized, multicenter study at 4 German prehospital emergency medicine centers. One hundred sixty-eight adult patients requiring prehospital emergency intubation were treated by an emergency physician and randomized to 1 of 3 portable videolaryngoscopes (A.P. Advance, C-MAC PM, and channeled blade KingVision) with different blade types. The primary outcome variable was overall intubation success and secondary outcomes included first-attempt intubation success, glottis visualization, and difficulty with handling the devices. P values for pairwise comparisons are corrected by the Bonferroni method for 3 tests (P[BF]). All presented P values are adjusted for center.

RESULTS

Glottis visualization was comparable with all 3 devices. Overall intubation success for A.P. Advance, C-MAC, and KingVision was 96%, 97%, and 61%, respectively (overall: P < .001, A.P. Advance versus C-MAC: odds ratio [OR], 0.97, 95% confidence interval [CI], 0.13-7.42, P[BF] > 0.99; A.P. Advance versus KingVision: OR, 0.043, 95% CI, 0.0088-0.21, P[BF] < 0.001; C-MAC versus KingVision: OR, 0.043, 95% CI, 0.0088-0.21, P[BF] < 0.001). Intubation success on the first attempt with A.P. Advance, C-MAC, and KingVision was 86%, 85%, and 48%, respectively (overall: P < .001, A.P. Advance versus C-MAC: OR, 0.89, 95% CI, 0.31-2.53, P[BF] > 0.99; A.P. Advance versus KingVision: OR, 0.24, 95% CI, 0.055-0.38, P[BF] = 0.0054; C-MAC versus KingVision: OR, 0.21, 95% CI, 0.043-.34, P[BF] < 0.003). Direct laryngoscopy for successful intubation with the videolaryngoscopic device was necessary with the A.P. Advance in 5 patients, and with the C-MAC in 4 patients. In the KingVision group, 21 patients were intubated with an alternative device.

CONCLUSIONS

During prehospital emergency endotracheal intubation performed by emergency physicians, success rates of 3 commercially available videolaryngoscopes A.P. Advance, C-MAC PM, and KingVision varied markedly. We also found that although any of the videolaryngoscopes provided an adequate view, actual intubation was more difficult with the channeled blade KingVision.

A comparison of airway management devices in simulated entrapment-trauma: a prospective manikin study

INTRODUCTION

In the patient entrapped after a motor vehicle collision (MVC), advanced airway management may need to be performed before extrication. The aim of this study was to compare four airway management devices utilized by paramedics in a simulated entrapped patient.

METHODS

Twenty-six paramedics performed advanced airway management on a manikin seated in the driver's seat (right side) of a car. Access was through the opened door only. The airway devices were the Macintosh laryngoscope and the Airtraq optical laryngoscope to facilitate the endotracheal intubation (ETI), the laryngeal mask airway (LMA) Supreme and the laryngeal tube (LT). Time to first successful ventilation and number of attempts required for successful placement were measured. Following each placement, participants rated the degree of difficulty. For ETI, participants ranked the achieved glottic view using Cormack-Lehane grades (CLG). Finally, participants were asked which airway management device they preferred.

RESULTS

The LMA Supreme had the shortest mean time to first successful ventilation (16.7 s, CI [0.95] 14.9-18.6). Insertion of the LMA Supreme and ETI with the Macintosh laryngoscope had 100% first-attempt success. The LMA Supreme was rated least difficult to insert (mean score 1.7/10 (CI [0.95] 1.2-2.1)). Compared to the Macintosh, the Airtraq laryngoscope facilitated superior laryngoscopy (CLG I view 46.2% and 80.8%, respectively). Most participants (10/26; 38%) chose the Macintosh laryngoscope as their preferred technique, followed closely by the LMA Supreme (9/26; 35%).

CONCLUSION

The LMA Supreme took the least amount of time and was the easiest to be inserted. Extraglottic airway devices may be beneficial alternative airway management devices to be considered by paramedics in the entrapped patient. Endotracheal intubation using the Macintosh laryngoscope was performed competently by participating paramedics. The Airtraq enabled superior laryngoscopy but resulted in poorer first-pass success rate.

Arterial blood gas changes during cardiac arrest and cardiopulmonary resuscitation combined with passive oxygenation/ventilation: a METI HPS study

Objective

High-fidelity simulators can simulate physiological responses to medical interventions. The dynamics of the partial arterial pressure of oxygen (P_aO₂), partial arterial pressure of carbon dioxide (P_aCO₂), and oxygen pulse saturation (SpO₂) during simulated cardiopulmonary resuscitation (CPR) were observed and compared with the results from the literature.

Methods

Three periods of cardiac arrest were simulated using the METI Human Patient Simulator™ (Medical Education Technologies, Inc., Sarasota, FL, USA): cardiac arrest, chest compression-only CPR, and chest compression-only CPR with continuous flow insufflation of oxygen (CFIO).

Results

In the first period, the observed values remained constant. In the second period, P_aCO₂ started to rise and peaked at 63.5 mmHg. In the CFIO period, P_aCO₂ slightly fell. P_aO₂ and S_pO₂ declined only in the second period, reaching their lowest values of 44 mmHg and 70%, respectively. In the CFIO period, P_aO₂ began to rise and peaked at 614 mmHg. S_pO₂ exceeded 94% after 2 minutes of CFIO.

Conclusions

The METI Human Patient Simulator™ accurately simulated the dynamics of changes in P_aCO₂. Use of this METI oxygenation model has some limitations because the simulated levels of P_aO₂ and S_pO₂ during cardiac arrest correlate poorly with the results from published studies.

The role of videolaryngoscope in endotracheal intubation training programs

Background

Macintosh laryngoscopes are widely used for endotracheal intubation training of medical students and paramedics whereas there are studies in the literature that supports videolaryngoscopes are superior in endotracheal intubation training. Our aim is to compare the endotracheal intubation time and success rates of videolaryngoscopes and Macintosh laryngoscopes during endotracheal intubation training and to determine the endotracheal intubation performance of the students when they have to use an endotracheal intubation device other than they have used during their education.

Methods

Endotracheal intubation was performed on a human manikin owing a standard respiratory tract by Macintosh laryngoscopes and C-MAC^® videolaryngoscope (Karl Storz, Tuttligen, Germany). Eighty paramedic students were randomly allocated to four groups. At the first week of the study 10 endotracheal intubation trials were performed where, Group-MM and Group-MV used Macintosh laryngoscopes; Group-VV and Group-VM used videolaryngoscopes. Four weeks later all groups performed another 10 endotracheal intubation trial where Macintosh laryngoscopes was used in Group-MM and Group-VM and videolaryngoscopes used in Group-VV and Group-MV.

Results

Success rates increased in the last 10 endotracheal intubation attempt in groups MM, VV and MV (p = 0.011; p = 0.021, p = 0.290 respectively) whereas a decrease was observed in group-VM (p = 0.008).

Conclusions

The success rate of endotracheal intubation decreases in paramedic students who used VL during endotracheal intubation education and had to use Macintosh laryngoscopes later. Therefore we believe that solely videolaryngoscopes is not enough in endotracheal intubation training programs.

Laryngoscopes for difficult airway scenarios: a comparison of the available devices

INTRODUCTION

According to the American Society of Anesthesiologists, the incidence of difficult intubation in the operating room is 1.2-3.8%; however, in emergency conditions, this rate is higher and reaches even 5.3%. Successful emergency airway management is an essential component of the modern practice of medicine.

AREAS COVERED

The aim of the study is to review the literature regarding different devices used to perform endotracheal intubation (Macintosh, Miller, and McCoy laryngoscopes; ETView, GlideScope, TruView, Airtraq, McGrath MAC, Pentax AWS, Trachlight, Shikani, and Bullard) and discuss their clinical and experimental role in difficult airway management.

EXPERT COMMENTARY

Owing to the development of medical technology, there are an increasing number of videolaryngoscopes and other devices facilitating endotracheal intubation in difficult airway scenarios, including cardiopulmonary resuscitation, cervical spine injury, or face-to-face intubation. Each of these devices may bring benefits in the form of increasing the intubation effectiveness, as well as shortening the procedure, provided that the person performing intubation is familiar with the use of the device.

[The role of videolaryngoscope in endotracheal intubation training programs]

BACKGROUND

Macintosh laryngoscopes are widely used for endotracheal intubation training of medical students and paramedics whereas there are studies in the literature that supports videolaryngoscopes are superior in endotracheal intubation training. Our aim is to compare the endotracheal intubation time and success rates of videolaryngoscopes and Macintosh laryngoscopes during endotracheal intubation training and to determine the endotracheal intubation performance of the students when they have to use an endotracheal intubation device other than they have used during their education.

METHODS

Endotracheal intubation was performed on a human manikin owing a standard respiratory tract by Macintosh laryngoscopes and C-MAC^® videolaryngoscope (Karl Storz, Tuttligen, Germany). Eighty paramedic students were randomly allocated to four groups. At the first week of the study 10 endotracheal intubation trials were performed where, Group-MM and Group-MV used Macintosh laryngoscopes; Group-VV and Group-VM used videolaryngoscopes. Four weeks later all groups performed another 10 endotracheal intubation trial where Macintosh laryngoscopes was used in Group-MM and Group-VM and videolaryngoscopes used in Group-VV and Group-MV.

RESULTS

Success rates increased in the last 10 endotracheal intubation attempt in groups MM, VV and MV (p=0.011; p=0.021, p=0.290 respectively) whereas a decrease was observed in group-VM (p=0.008).

CONCLUSIONS

The success rate of endotracheal intubation decreases in paramedic students who used VL during endotracheal intubation education and had to use Macintosh laryngoscopes later. Therefore we believe that solely videolaryngoscopes is not enough in endotracheal intubation training programs.

Comparison of the Pentax AirwayScope and McGrath MAC videolaryngoscope for endotracheal intubation in patients with a normal airway

Various videolaryngoscopes (VLs) have been developed to provide a better laryngeal view and facilitate difficult intubations. The goal of this study was to compare 2 VLs, the Pentax AWS and the McGrath VL, with respect to intubation time and ease of intubation.One hundred forty patients aged 19 to 65 years (American Society of Anesthesiologists classification I or II), who required tracheal intubation for elective surgery, were randomly assigned to 1 of the 2 groups: the Pentax AWS (n = 70) or the McGrath VL (n = 70). The primary outcome was time to intubation (TTI) measured by a blind observer. The intubation difficulty scale (IDS), percentage of glottic opening (POGO) scale, glottic grade, use of optimal external laryngeal manipulation (OELM), and ease of intubation were also recorded.The Pentax AWS provided a better laryngeal view than the McGrath VL with respect to the Cormack-Lehane (CL) glottic grade (1/2a/2b) (63/7/0 vs 43/24/3, P < .001) and the POGO scale (median [interquartile range, IQR]) (100 [100-100] vs 100 [80-100], P < .001). The IDS was significantly lower in the Pentax AWS group compared with the McGrath VL group (median [IQR]) (0 [0-0] vs 0 [0-1], P < .001). However, the TTI was similar in both the Pentax AWS and McGrath VL groups (median [IQR]) (30 [27-34] vs 32 [27-35] seconds, P = .440). OELM and ease of intubation were also similar between the 2 groups.The Pentax AWS offered a superior laryngeal view compared with the McGrath VL. There was no significant difference in either the intubation time or ease of intubation using these 2 devices in patients with normal airways.

Comparison of airway management techniques for different access in a simulated motor vehicle entrapment scenario

BACKGROUND

Emergency airway management can be particularly challenging in patients entrapped in crashed cars because of limited access. The aim of this study was to analyse the feasibility of four different airway devices in various standardized settings utilized by paramedics and emergency physicians.

METHODS

Twenty-five paramedics and 25 emergency physicians were asked to perform advanced airway management in a manikin entrapped in a car's left front seat, with access to the patient through the opened driver's door or access from the back seat. Available airway devices included Macintosh and Airtraq laryngoscopes, as well as laryngeal mask airway (LMA) Supreme and the Laryngeal Tube. The primary endpoints were successful placement, along with attempts needed to do so, and time for successful placement. The secondary endpoints included Cormack-Lehane grades and rating of the difficulty of the technique with the different devices.

RESULTS

The overall intubation and placement success rates were equal for the Macintosh and Airtraq laryngoscopes as well as the LMA Supreme and Laryngeal Tube, with access from the back seat being superior in terms of placement time and ease of use. Supraglottic airway devices required half of the placement time and were easier to use compared with endotracheal tubes (with placement times almost >30 s). Paramedics and emergency physicians achieved equal overall successful placement rates for all devices.

CONCLUSION

Both scenarios of securing the airway seem suitable in this manikin study, with access from the back seat being superior. Although all airway devices were applicable by both groups, paramedics and emergency physicians, supraglottic device placement was faster and always possible at the first attempt. Therefore, the LMA Supreme and the Laryngeal Tube are attractive alternatives for airway management in this context if endotracheal tube placement fails. Furthermore, supraglottic device placement, while the patient is still in the vehicle, followed by a definitive airway once the patient is extricated would be a worthwhile alternative course of action.

McGrath Series 5 videolaryngoscope vs Airtraq DL videolaryngoscope for double-lumen tube intubation: A randomized trial

BACKGROUND

Many studies have shown Airtraq videolaryngoscope provided faster tracheal intubation and a higher success rate than other videolaryngoscopes. Recently, different types of videolaryngoscopes have been reported for use in double-lumen tube (DLT) intubation. However, the advantages and disadvantages between them remain undetermined for DLT intubation. In this study, we compared the Airtraq DL videolaryngoscope with the McGrath Series 5 videolaryngoscope for DLT intubation by experienced anesthesiologists.

METHODS

Ninety patients with expected normal airways were randomly allocated to either the Airtraq or McGrath group. The primary outcome was DLT intubation time. The secondary outcomes were glottic view, success rate, subjective ease of intubation (100-mm visual analog scale, 0 = easy; 100 = difficult), incidence of DLT malposition, and postoperative intubation-related complication.

RESULTS

The airway characteristics were comparable between the 2 groups. Cormack and Lehane grades significantly improved with the use of the McGrath and Airtraq videolaryngoscopes, compared with the Macintosh laryngoscope. The intubation success rate on the first attempt was 93% in the Airtraq group and 95% in the McGrath group (P > 0.05). The intubation time in the McGrath group is longer than that in the Airtraq group (39.9 [9.1]s vs 28.6 [13.6]s, P < 0.05). But intubation difficulty score, the incidence of DLT malposition and intubation-related complication were comparable between groups (P > 0.05).

CONCLUSIONS

When using videolaryngoscopes for DLT intubation, the Airtraq DL is superior to the McGrath Series 5 in intubation time, but it does not decrease intubation difficulty.

Airway management for anaesthesia in the ambulatory setting

PURPOSE OF REVIEW

The number of anaesthetic procedures in the ambulatory setting is steadily increasing. During the last years, more and more patients with complex medical conditions undergo ambulatory interventions. This review will focus on airway management practices, but especially on techniques used in the ambulatory setting. It will highlight recent literature published in the focus of ambulatory anaesthesia and will discuss relevant findings of the last year.

METHODS

Literature search and analysis performed independently by two reviewers.

RECENT FINDINGS

Practical points to improve success of anaesthesia and to avoid complications in the ambulatory setting are provided. In addition to concepts for the (un)expected difficult airway, new supraglottic devices, and modern concepts for teleconsultation, are discussed.

SUMMARY

There are several points which should be considered for ambulatory anaesthesia. Selected patient groups (e.g., obstructive sleep apnoea, obesity) may have a higher anaesthesia-related risk. To handle the more and more complex conditions in a growing number of ambulatory patients, straightforward concepts, especially for the (un)expected difficult airway, are required.

Perioperative sleep apnea: a real problem or did we invent a new disease?

Depending on the subpopulation, obstructive sleep apnea (OSA) can affect more than 75% of surgical patients. An increasing body of evidence supports the association between OSA  and perioperative complications, but some data indicate important perioperative outcomes do not differ between patients with and without OSA. In this review we will provide an overview of the pathophysiology of sleep apnea and the risk factors for perioperative complications related to sleep apnea. We also discuss a clinical algorithm for the identification and management of OSA patients facing surgery.

The AirView Study: Comparison of Intubation Conditions and Ease between the Airtraq-AirView and the King Vision

We conducted a study assessing the quality and speed of intubation between the Airtraq with its new iPhone AirView app and the King Vision in a manikin. The primary endpoint was reduction of time needed for intubation. Secondary endpoints included times necessary for intubation. 30 anaesthetists randomly performed 3 intubations with each device on a difficult airway manikin. Participants had a professional experience of 12 years: 60.0% possessed the Airtraq in their hospital, 46.7% the King Vision, and 20.0% both. Median time difference [IQR] to identify glottis (1.1 [-1.3; 3.9] P = 0.019), for tube insertion (2.1 [-2.6; 9.4] P = 0.002) and lung ventilation (2.8 [-2.4; 11.5] P = 0.001), was shorter with the Airtraq-AirView. Median time for glottis visualization was significantly shorter with the Airtraq-AirView (5.3 [4.0; 8.4] versus 6.4 [4.6; 9.1]). Cormack Lehane before intubation was better with the King Vision (P = 0.03); no difference was noted during intubation, for subjective device insertion or quality of epiglottis visualisation. Assessment of tracheal tube insertion was better with the Airtraq-AirView. The Airtraq-AirView allows faster identification of the landmarks and intubation in a difficult airway manikin, while clinical relevance remains to be studied. Anaesthetists assessed the intubation better with the Airtraq-AirView.

Truview EVO2 and standard Macintosh laryngoscope for tracheal intubation during cardiopulmonary resuscitation: a comparative randomized crossover study

The aim of this study was to compare the performance of the Truview EVO2 laryngoscope in manikin-simulated cardiopulmonary resuscitation (CPR) and no-CPR scenarios with standard intubation technique. Participants performed 4 scenarios in random order: endotracheal intubation (ETI) using Macintosh laryngoscope (MCL), Truview EVO2 laryngoscope in no-CPR patient scenario, and intubation during uninterrupted chest compressions using both laryngoscopes. The participants were directed to make 3 attempts in each scenario. Primary outcomes were time to tracheal intubation (TTI) and intubation success, whereas secondary outcomes were cumulative success ratio and the number of esophageal intubation (EI). TTI and success ratios were reported per attempt. Thirty paramedics completed the study. Median TTI with Truview EVO2 with CPR was 36 (interquartile range [IQR] 29.00-52.00), 22.5 (IQR 18.33-35.00), and 18 (IQR 11.00-23.00) seconds; MCL with CPR was 23 (IQR 18.92-36.90), 16.8 (IQR 14.00-22.31), and 14.5 (IQR 11.12-16.36) seconds; Truview EVO2 without CPR was 28.6 (IQR 24.02-38.34), 21.7 (IQR 17.00-25.00), and 13 (IQR 11.90-17.79) seconds; MCL without CPR was 17 (IQR 13.23-22.29), 13 (IQR 12.09-15.26), and 12.4 (IQR 10.08-19.84) seconds for first, second, and third attempts, respectively. The P values for differences in TTI between Truview EVO2 and MCL were P < 0.0001, P = 0.0540, and P = 0.7550 in CPR scenario and P = 0.0080, P = 0.1570, and P = 0.7652 in no-CPR scenario for first, second, and third attempts, respectively. The success ratios for each of the scenarios were as follows: in CPR scenario it was 0.73 versus 0.53 (P = 0.0558), 0.83 versus 0.76 (P = 0.2633), and 1 versus 0.8 (P = 0.0058); in no-CPR scenario it was 0.63 versus 0.73 (P = 0.2068), 0.86 versus 0.86, and 0.97 versus 1 (P = 0.1637) for Truview EVO2 vs MCL in first, second, and third attempts, respectively. The cumulative success ratio related to the time of ETI was better for MCL compared with Truview EVO2 laryngoscope in both scenarios (P = 0.0029 and P = 0.0004 in no-CPR and CPR scenarios). The number of EI with MCL was 30% versus 13.3% (P = 0.0113), and for Truview EVO2 it was 20.45% versus 15.56% in CPR and no-CPR scenarios, respectively. The application of Truview EVO2 during uninterrupted chest compressions increased TTI but increased the success ratio of ETI and decreased number of EIs.

Use of the Airtraq® device for airway management in the prehospital setting--a retrospective study

Background

Difficulties with prehospital intubations have encouraged the development of indirect laryngoscopy techniques, facilitating laryngeal visualization. Airtraq® is a relatively new single-use indirect laryngoscope. The Airtraq® has been evaluated in several prehospital mannequin intubation trials. However, prehospital clinical experience with the device is limited.

Methods

A retrospective medical chart review was performed for patients who underwent prehospital endotracheal intubation in the Stockholm County between January 2008 and December 2012. Both anaesthesiologists and nurse anaesthetists performed prehospital intubations during the study period. All Airtraq® intubations during this period were included in the analysis. The objective was to estimate the success rate of Airtraq® used in a prehospital setting.

Results

During the 5-year period (January 2008- December 2012), 2453 tracheal intubations were performed. Airtraq® was used in 28 cases (1%). The overall Airtraq® intubation success rate was 68%. Among patients with anticipated or unexpected difficult airway (23/28) the Airtraq® success rate was 61% (14/23). Among patients who underwent drug facilitated or rapid-sequence intubation protocols 4/5 (80%) were successfully intubated with Airtraq®.

Conclusion

In conclusion, this retrospective study showed a higher Airtraq® success rate than previous prospective prehospital trials. However, compared to other prehospital direct and indirect intubation methods the Airtraq success rate is low. Further clinical trials are necessary to evaluate the role of Airtraq® in the prehospital airway management.

Ventilatory management and extubation criteria of the neurological/neurosurgical patient

Approximately 200 000 patients per year will require mechanical ventilation secondary to neurological injury or disease. The associated mortality, morbidity, and costs are significant. The neurological patient presents a unique set of challenges to airway management, mechanical ventilation, and defining extubation readiness. Neurological injury and disease can directly or indirectly involve the process involved with respiration or airway control. This article will review the basics of airway management and mechanical ventilation in the neurological patient. The current state of the literature evaluating extubation criteria in the neurological patient will also be reviewed.

What is the accuracy of the high-fidelity METI Human Patient Simulator physiological models during oxygen administration and apnea maneuvers?

BACKGROUND

A widely used physiological simulator is generally accepted to give valid predictions of oxygenation status during disturbances in breathing associated with anesthesia. We compared predicted measures with physiological measurements available in the literature, or derived from other models.

METHODS

Five studies were selected from the literature which explored arterial oxygenation, with or without preoxygenation, in clinical situations or through mathematical modeling as well as the evolution of the fraction of expired oxygen (Feo2) during preoxygenation maneuvers. Scenarios from these studies were simulated on the METI-Human Patient Simulator™ simulator, and the data were compared with the results in the literature.

RESULTS

Crash-induction anesthesia without preoxygenation induces an O2 pulse saturation (Spo2) decrease that is not observed on the METI simulator. In humans, after 8 minutes of apnea, Spo2 decreased below 90% while the worst value was 95% during the simulation. The apnea time to reach 85% was less with obese patients than with healthy simulated patients and was shortened in the absence of preoxygenation. However, the data in the literature include METI simulator confidence interval 95% values only for healthy humans receiving preoxygenation. The decrease in Pao2 during 35-second apnea started at end-expiration was slower on the METI simulator than the values reported in the literature. Feo2 evolution during preoxygenation maneuvers on the METI simulator with various inspired oxygen fractions (100%, 92%, 84%, and 68%) was very close to those reported in humans when perfect mask seal is provided. In practice, this seal is impossible to obtain on the METI simulator.

CONCLUSIONS

Spo2 decreased much later during apnea on the METI simulator than in a clinical situation, whether preoxygenation was performed or not. The debriefing after simulation of critical situations or the use of the METI simulator to test a new equipment must consider these results.