Use of GlideScope® in adults: an overview

This paper is an overview of the literature concerning the "know how" of the GlideScope® use in adults. We summarized the main evidences of the last 10 years with particular attention to experts' suggestions about clinical practice of the GlideScope®, noticing matters still debated on GlideScope® use. We used PubMed to search publications from January 2003 to June 2013 using the search terms "GlideScope", "video laryngoscope" and "videolaryngoscopy". These publications were searched manually or references to further publication not identified using PubMed. All works that made a point worth including were cited in the discussion. Our research confirms the value of GlideScope® use in airway management and highlights the debate about the use of videolaryngoscopes in routine cases and the operators who may use them in clinical practice.

Does prewarming the i-gel supraglottic airway device fit the larynx better compared to keeping it at room temperature for non-paralysed, sedated patients: a randomised controlled trial

OBJECTIVE

This study aimed to test the hypothesis that the i-gel supraglottic airway device would fit the larynx and provide better sealing pressure if prewarmed to 42°C relative to the device kept at room temperature in non-paralysed, sedated patients.

METHODS

A total of 74 adult patients were assigned to the warm (i-gel prewarmed to 42°C; W group; 37 patients) or the control (i-gel kept at room temperature; C group; 37 patients) groups. Anaesthesia was induced with propofol and fentanyl. The i-gel was prewarmed to 42°C for 30 min before insertion in the W group, but kept at room temperature (approximately 23°C) for the C group. The number of attempts made until successful insertion and sealing pressure were compared between the two groups.

RESULTS

Insertion was successful with one attempt in 35 cases each for the W and C groups. Two attempts were needed in two cases for the W group and one case for the C group. There was one failed attempt in the C group, but none in the W group. None of the differences between the two groups were significant (p=0.51). Sealing pressure was slightly, but not significantly, higher in the W group than in the C group (W group 22.6±6.1 cm H2O; C group 20.7±6.1 cm H2O; p=0.15).

CONCLUSIONS

Prewarming of the i-gel to 42°C did not increase the success rate of insertion, nor did it significantly increase sealing pressure in anaesthetised, non-paralysed patients. Our data suggest that we can keep the i-gel at room temperature for emergency airway management for non-paralysed, sedated patients.

TRIAL REGISTRATION NUMBER

University Medical Information Network, Japan 000012287.

What do we need for airway management of adult casualties on the Primary Casualty Receiving Facility? A review of airway management on Role 3 Afloat

The Primary Casualty Receiving Facility (PCRF) of the Royal Navy (RN) is currently based on Royal Fleet Auxiliary (RFA) ARGUS and provides a functioning hospital with surgical teams and a CT scanner (Role 3) within the maritime environment. The case mix could include complex trauma, critically ill patients returning to theatre several times, as well as non-battle injury procedures. This paper describes how we have used national guidelines, evidence from recent military experience, and the Clinical Guidelines for Operations (CGOs) to review and rationalise the airway equipment that is available and that would be required for the PCRF in its current configuration, whilst maintaining capability in a deployed setting.

Cardiac arrest equipment to support airway

Each hospital should have standardised cardiac arrest trolleys equipped with all the instruments and medication needed to deal with an acute adult cardiac arrest. Nurses must know the contents of these trolleys and how to use them to fulfil their common role as first responder. This first article in a two-part series looks at equipment to aid airway management and breathing; part two will focus on circulation.

Cricothyrotomy performed with the Melker™ set or the QuickTrach™ kit: procedure times, learning curves and operators' preference

BACKGROUND

Cricothyroidotomy is a surgical airway technique in which an airway device is inserted into the trachea through an incision made at the cricothyroid membrane. It is used for the management of the "difficult airways" and may be a lifesaving procedure in "can't intubate, can't oxygenate" situations. However, many healthcare professionals working in emergency settings have little of no experience with this procedure. Achievement of theoretical and practical knowledge of different cricothyrotomy techniques is therefore a fundamental prerequisite for those healthcare professionals.

MATERIALS AND METHODS

In this study, 40 volunteers representative of different categories of healthcare professionals were enrolled for the theoretical and practical 1-day training course on cricothyrotomy. Two commercially available device for cricothyrotomy were used during the course, the Melker™ set, which involves the Seldinger technique, and the QuickTrach™ kit, which does not rely on the use of a guide-wire. Each participant performed a series of 5 attempts on a manikin with each kit. Procedure time was recorded, and satisfaction with the course, preference for each cricothyrotomy kit and self-rating of cricothyrotomy skills were assessed by a self-administered questionnaire.

RESULTS

Mean procedure time significantly decreased from the first to the last attempt (48.7±21.9 and 27.8±13.7 seconds, respectively; p<0.0001). The Melker™ set was the most preferred, being rated as "excellent" by 62% of participants. This preference was even more pronounced among anaesthesiologists, that are more familiar with the Seldinger technique. Participants' satisfaction was high: the course was rated as "excellent" by 66.7% of attendees, the theoretical and practical knowledge achieved was rated as "very useful" by 94% of all attendees and by 100% of the anaesthesiologists.

CONCLUSIONS

A systematic approach to teach healthcare professionals in the application of various devices for the management of the socalled "difficult airways" may maximize intubation success and minimize complication. The present study provides evidence for the efficacy of training courses in Emergency Departments aimed at improving theoretical and practical cricothyrotomy skills in emergency situations.

Inconsistent size nomenclature in extraglottic airway devices

BACKGROUND

Extraglottic airway devices (EADs) are frequently used airway devices, yet often they seal poorly, resulting in a functionally unacceptable leak. Optimal size selection of the EAD is therefore critical to the safe and effective use of an EAD. This review is designed to delineate the sizing recommendations of EADs and indicate the differences in order to make the optimal choice for device effectiveness and patient safety.

METHODS

We searched manufacturing' guidelines regarding size recommendations of EADs. Alternative size selection suggestions were obtained through an extensive literature search.

RESULTS

Most manufacturers offer different types and a wide range of (up to 8 different) sizes of EADs. Size ranges offered by manufacturers are most often based on weight, although some manufacturers offer alternative EADs based on a variety of patient variables (age, gender, height). Even 'one-size-fits-all' adult EADs have been introduced into clinical practice. Special formulae and methods are suggested to aid the clinician to find the optimal EAD size, especially for children.

CONCLUSION

Selecting the appropriate size of an EAD is critical to optimal use, although applying the correct size of an EAD has been subject of controversy, as recommendations on sizing differ substantially and are far from a coherent and universal sizing system. Successful use of an EAD depends in part on appropriate size selection, in addition to clinical judgment, as well as patient anatomy and physiology. Standardization in the use of EAD sizes and a consensus about a consistent size systematic of EADs would benefit to promote a safer clinical practice in airway management.

[Role of the i-gel in emergency airway management]

The i-gel is a relatively new supraglottic airway, which has been shown to be useful during general anesthesia, and it may have a potential role during cardiopulmonary resuscitation. In a manikin study, we have found that, compared with laryngeal mask airways, the i-gel was significantly easier and faster to insert, due mainly to no-necessity of cuff inflation. One possible difficulty in using the i-gel during cardiopulmonary resuscitation is that the device cannot be fixed with the Thomas Tube Holder (Laerdal Medical Japan KK, Tokyo, Japan). A specially tailored device for cardiopulmonary resuscitation, recently has become available. The pack includes the i-gel O2 (which has a side port for oxygen delivery), a suction catheter, a sachet containing lubrication jelly, and a fixation strap. We describe the role of the i-gel during emergency airway management.

Difficult mask ventilation in obese patients: analysis of predictive factors

BACKGROUND

This study aimed to determine the accuracy of commonly used preoperative difficult airway indices as predictors of difficult mask ventilation (DMV) in obese patients (BMI >30 kg/m2).

METHODS

In 309 consecutive obese patients undergoing general surgery, the modified Mallampati test, patient's Height/Thyromental distance ratio, Inter-Incisor Distance, Protruding Mandible (PM), history of Obstructive Sleep Apnea and Neck Circumference (NC) were recorded preoperatively. DMV was defined as Grade 3 mask ventilation (MV) by the Han's scale (MV inadequate, unstable or requiring two practitioners). Data are shown as means±SD or number and proportions. Independent DMV predictors were identified by multivariate analysis. The discriminating capacity of the model (ROC curve area) and adjusted weights for the risk factors (odds ratios) were also determined.

RESULTS

BMI averaged 42.5±8.3 kg/m2. DMV was reported in 27 out of 309 patients (8.8%; 95%CI 5.6-11.9%). The multivariate analysis retained NC (OR 1.17; P<0.0001), limited PM (1.99; P=0.046) and Mallampati test (OR 2.12; P=0.009) as risk predictors for DMV. Male gender was also included in the final model (OR 1.87; P=0.06) as biologically important variable albeit the borderline statistical significance. The model yielded a good discriminating capacity (ROC curve 0.85). The four parameters were used to create an unweighted prediction score (ROC curve 0.84) with >2 associated factors as the best discriminating point for DMV.

CONCLUSION

Obese patients show increased incidence of DMV with respect to the undifferentiated surgical population. Limited PM, Mallampati test and NC are important DMV predictors.

Comparison of success rates between two video laryngoscope systems used in a prehospital clinical trial

OBJECTIVES

The primary aims of this study were to compare paramedic success rates and complications of two different video laryngoscopes in a prehospital clinical study.

METHODS

This study was a multi-agency, prospective, non-randomized, cross over clinical trial involving paramedics from four different EMS agencies. Following completion of training sessions, six Storz CMAC™ video laryngoscopes and six King Vision™ (KV) video laryngoscopes were divided between agencies and placed into service for 6 months. Paramedics were instructed to use the video laryngoscope for all patients estimated to be ≥ 18 years old who required advanced airway management per standard operating procedure. After 6 months, the devices were crossed over for the final 6 months of the study period. Data collection was completed using a telephone data collection system with a member of the research team (available 24/7). First attempt success, overall success, and success by attempt, were compared between treatment groups using exact logistic regression adjusted for call type and user experience.

RESULTS

Over a 12-month period, 107 patients (66 CMAC, 41 KV) were treated with a study device. The CMAC had a significantly higher likelihood of first attempt success (OR = 1.85; 95% CI 0.74, 4.62; p = 0.188), overall success (OR = 7.37; 95% CI 1.73, 11.1; p = 0.002), and success by attempt (OR = 3.38; 95% CI 1.67, 6.8; p = 0.007) compared to KV. Providers reverted to direct laryngoscopy in 80% (27/34) of the video laryngoscope failure cases, with the remaining patients having their airways successfully managed with a supraglottic airway in 3 cases and bag-valve mask in 4 cases. The provider-reported complications were similar and none were statistically different between treatment groups. Complication rates were not statistically different between devices.

CONCLUSION

The CMAC had a higher likelihood of successful intubation compared to the King Vision. Complication rates were not statistically different between groups. Video laryngoscope placement success rates were not higher than our historical direct laryngoscopy success rates.

The Cric-Key™ and Cric-Knife™: a combined tube-introducer and scalpel-hook open cricothyrotomy system

The author describes a cricothyrotomy system that consists of two devices that, packaged together, are labeled the Control-Cric™ system. The Cric-Key™ was invented to verify tracheal location during surgical airway procedures?without the need for visualization, aspiration of air, or reliance on clinicians? fine motor skills. The Cric-Knife™ combines a scalpel with an overlying sliding hook to facilitate a smooth transition from membrane incision to hook insertion and tracheal control. In a recent test versus a traditional open technique, this system had a higher success rate and was faster to implement.

A comparative study of the efficacy of Pediatric Airtraq® with conventional laryngoscope in children

BACKGROUND

Management of pediatric airway may pose a challenge to anesthesiologists. Many modifications in maneuvers and equipments have been made overtime to overcome the problem. Pediatric optical laryngoscope (Airtraq®) is one of the newer equipments for managing simple and difficult pediatric airway. Here we have evaluated the comparative efficacy of pediatric Airtraq® optical laryngoscope with conventional laryngoscope in children scheduled for routine surgeries.

METHODS

After written informed consent from the parents/guardian of the children, they were allocated into two groups of 17 patients each using the pediatric Airtraq® in one and a conventional laryngoscope in the other. Airtraq® intubation patients were those in which pediatric Airtraq® was used to intubate whereas the patients who were intubated with conventional laryngoscope were labelled as conventional intubation group. The primary outcome measure was time needed for successful intubation whereas secondary outcome measures were number of attempts to intubate, POGO (percentage of glottic opening) scoring and complications like airway trauma and esophageal intubation.

RESULTS

It took significantly shorter time to intubate in Airtraq® intubation group of patients as compared to Conventional intubation group of patients (P<0.05). Similarly the POGO scoring was significantly better in Airtraq intubation compared to Conventional intubation (P <0.001). Number of attempts to intubate and complications like airway trauma and esophageal intubation using Airtraq® was less frequent compared to conventional laryngoscopy but the difference was statistically insignificant.

CONCLUSION

Pediatric Airtraq® provides better intubating conditions in children compared to conventional laryngoscope with less frequent complications.

Successful management of trachea stenosis with massive substernal goiter via thacheobronchial stent

A case of 65 year-old Chinese male patient with severe tracheal stenosis due to a massive substernal goiter, is presented. MRI and CT scan revealed that the massive substernal goiter was 9.3 × 6.1 × 4.7 cm in size, displacing the trachea and adjacent large vessels to the patient's right contributing to severe intrathoracic trachea compression up to 6 cm in length and the narrowest caliber of the trachea only 3.0 mm in diameter. To the best of our knowledge, optimal airway management for the massive substernal goiter resection was considered to be temporary tracheobronchial stent placement pre-operation.

Supraglottic airway devices versus tracheal intubation for airway management during general anaesthesia in obese patients

BACKGROUND

The number of obese patients requiring general anaesthesia is likely to increase in coming years, and obese patients pose considerable challenges to the anaesthetic team. Tracheal intubation may be more difficult and risk of aspiration of gastric contents into the lungs is increased in obese patients. Supraglottic airway devices (SADs) offer an alternative airway to traditional tracheal intubation with potential benefits, including ease of fit and less airway disturbance. Although SADs are now widely used, clinical concerns remain that their use for airway management in obese patients may increase the risk of serious complications.

OBJECTIVES

We wished to examine whether supraglottic airway devices can be used as a safe and effective alternative to tracheal intubation in securing the airway during general anaesthesia in obese patients (with a body mass index (BMI) > 30 kg/m(2)).

SEARCH METHODS

We searched for eligible trials in the following databases: Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 8, 2012), MEDLINE via Ovid (from 1985 to 9 September 2012) and EMBASE via Ovid (from 1985 to 9 September 2012). The Cochrane highly sensitive filter for randomized controlled trials was applied in MEDLINE and EMBASE. We also searched trial registers such as www.clinicaltrials.gov and the Current Controlled Clinical Trials Website (http://www.controlled-trials.com/) for ongoing trials. The start date of these searches was limited to 1985, shortly before the first SAD was introduced, in 1988. We undertook forward and backward citation tracing for key review articles and eligible articles identified through the electronic resources.

SELECTION CRITERIA

We considered all randomized controlled trials of participants aged 16 years and older with a BMI > 30 kg/m(2) undergoing general anaesthesia. We compared the use of any model of SAD with the use of tracheal tubes (TTs) of any design.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. Two review authors independently assessed trial quality and extracted data, including information on adverse events. We contacted study authors for additional information. If sufficient data were available, results were presented as pooled risk ratios (RRs) with 95% confidence intervals (CIs) based on random-effects models (inverse variance method). We employed the Chi(2) test and calculated the I(2) statistic to investigate study heterogeneity.

MAIN RESULTS

We identified two eligible studies, both comparing the use of one model of SAD, the ProSeal laryngeal mask airway (PLMA) with a TT, with a total study population of 232. One study population underwent laparoscopic surgery. The included studies were generally of high quality, but there was an unavoidable high risk of bias in the main airway variables, such as change of device or laryngospasm, as the intubator could not be blinded. Many outcomes included data from one study only.A total of 5/118 (4.2%) participants randomly assigned to PLMA across both studies were changed to TT insertion because of failed or unsatisfactory placement of the device. Postoperative episodes of hypoxaemia (oxygen saturation < 92% whilst breathing air) were less common in the PLMA groups (RR 0.27, 95% CI 0.10 to 0.72). We found a significant postoperative difference in mean oxygen saturation, with saturation 2.54% higher in the PLMA group (95% CI 1.09% to 4.00%). This analysis showed high levels of heterogeneity between results (I(2) = 71%). The leak fraction was significantly higher in the PLMA group, with the largest difference seen during abdominal insufflation－a 6.4% increase in the PLMA group (95% CI 3.07% to 9.73%).No cases of pulmonary aspiration of gastric contents, mortality or serious respiratory complications were reported in either study. We are therefore unable to present effect estimates for these outcomes.In all, 2/118 participants with a PLMA suffered laryngospam or bronchospasm compared with 4/114 participants with a TT. The pooled estimate shows a non-significant reduction in laryngospasm in the PLMA group (RR 0.48, 95% CI 0.09 to 2.59).Postoperative coughing was less common in the PLMA group (RR 0.10, 95% CI 0.03 to 0.31), and there was no significant difference in the risk of sore throat or dysphonia (RR 0.25, 95% CI 0.03 to 2.13). On average, PLMA placement took 5.9 seconds longer than TT placement (95% CI 3 seconds to 8.8 seconds). There was no significant difference in the proportion of successful first placements of a device, with 33/35 (94.2%) first-time successes in the PLMA group and 32/35 (91.4%) in the TT group.

AUTHORS' CONCLUSIONS

We have inadequate information to draw conclusions about safety, and we can only comment on one design of SAD (the PLMA) in obese patients. We conclude that during routine and laparoscopic surgery, PLMAs may take a few seconds longer to insert, but this is unlikely to be a matter of clinical importance. A failure rate of 3% to 5% can be anticipated in obese patients. However, once fitted, PLMAs provide at least as good oxygenation, with the caveat that the leak fraction may increase, although in the included studies, this did not affect ventilation. We found significant improvement in oxygenation during and after surgery, indicating better pulmonary performance of the PLMA, and reduced postoperative coughing, suggesting better recovery for patients.