GlideScope Use in Routine Clinical Practice

                                                                    Anesthesiology, V 114 • No 1 34-41 

Reported Results:

GlideScope use was studied in the  Oregon Health and Science University, Portland  and also the University of Michigan , Ann Arbor where during the study period 71,570 endotracheal intubations were reviewed and there were 2,004 GlideScope applications .
Overall GlideScope success:                                    97% (1,944 / 2,004)
Primary GlideScope use success:                            98% (1,712 / 1,755)
Predictors of difficult DL  GlideScope success      96% (1,377 / 1,428)
GlideScope rescue after failed  DL                          94% (244 / 239)
GlideScope rescue after failed Fiberoptic scope     80% (8 / 100)

Complications:
    Minor - soft tissue injury                                                    1%      (21 / 2,004)
    Major 0.3 % - Pharyngeal, tracheal ,laryngeal injury    0.3%   (6 / 2,004)

Limitations:
    The GlideScope failure was associated with neck radiation, neck mass, or a surgical scar by the Aziz group study.

Comment:
This study is significant because the GlideScope was used in institutions where the use is taught on a regular basis and use as a rescue device is well established.  The ASA difficult airway algorithm is used and regularly taught as well. The use for failed FOB use is interesting because the FOB is widely regarded as the "Gold Standard" technology for difficult airway management.
The effectiveness shown in this excellent study supports the anecdotal information in the field where many users consider GlideScope 60 degree angle scopes to be the most effective rescue available for difficult airway management.

The use of video laryngoscopy as a first line with GlideScope has been practiced in many ED units and some ORs  and this practice is growing.

Caldiroli devised what he considered to be an optimal practice where the GlideScope was used according to a pre-application assessment using the El Ganzouri index. The reported results on 6,276 patients demonstrated  difficult GlideScope video laryngoscopy in only 0.14% or 14 patents. The predictive value was very high when EGRI was 0-6 . The other advantage of this strategy is that  regular use leads to very high skill levels among the anesthesiology team. The least optimal pattern of behaviour is when rescue tools are only used with unexpected difficult conditions where skills may be found to be wanting.

Reference:

1. Caldiroli  A new difficult airway algorithm based on the El Ganzouri Index GlideScope video laryngoscope. a new look for intubation. Minerva Anesthesiologica vol. 77 2011
2. El Ganzouri   Preoperative Airway Assessment: predictive value of a multivariate risk index. Anesth Analg 1996; 82;1197-2004.

            

Position Analysis for GlideScope Intubation

Recent SAM discussion -GlideScope Patient Positioning- how to Analyse.

What are the principles one needs to apply when assessing patient positioning with the highly angled video laryngoscope-GlideScope?

The GlideScope was designed to accept the patient anatomy and provide an airway view by positioning the camera in the pharynx viewing the glottis by lifting the tongue along its length without excessive lifting of the glottis itself. The inspection of Adnet's lateral view of MRI Airway images is instructive. The interception of the MA (mouth angle) and the PA (pharyngeal angle) produces an angle which I have termed the Alpha Angle which is 60 degrees. The GlideScope exploits this underlying information to produce 99.9% usable airway views without excessive lifting of the glottic complex.

Obesity

The obese patient has several features that may make GlideScope laryngoscopy difficult. The first of these is excessive fat deposits in the region of the pharynx. Usually this fat does not prevent viewing as one stays in the midline and can do some extra lifting of the tongue.

There is often a prominent Buffalo Hump fat deposit in the inter scapular region which has the effect of elevating the thorax in a way that allows the neck to extend with consequent head position more posterior. This posterior position of the neck may increase the angle created by the LA (laryngeal angle) and the PA (pharyngeal angle) and make passage of the endotracheal  tube more challenging. Placement of a doughnut to pillow under the head to produce a neutral neck angle is probably helpful in most patients to restore normality.

The other consideration that may be useful is to place the patient in a moderate reverse Trendelenberg position, on some form of ramping or table flexion that reduces the work of breathing while intubation is being anticipated. This must be combined with consideration of venous return and cardiovascular status.

Excessive sniffing position may change the angles of the airway adversely so if one does this one must be ready to adjust the neck to a neutral position if tube advancement is an issue

Normal Patient

The normal anatomy accommodates the GlideScope in the neutral neck position which keeps the MA, LA, and PA angles in usual relationship and as far as we know now is the recommended position. Studies on this topic may shed more light in the future.

The factors leading to difficulty advancing the endotracheal tube when using the GlideScope were identified in 2001 when initial studies were done. These are:

1. deep insertion of the GlideScope

2. excessive lifting of the glottis- one must lift the tongue with addition of a slight 2 finger lifting of the blade tip _just enough to give a grade 2 view.

3. Slight withdrawal of the blade will allow the glottic complex to resume its normal position which is adjacent to the posterior pharyngeal wall. This position favors intubation.

Management of the Super Obese- Unofficial SAM BMI Record- 163.

 Awake Intubation .

       In 2007 This 945 lb. case was reported by Cleveland Clinic Anesthesiologists Dr. John Doyle and Dr. Andrew Zura , Rakmachandran M ,Lin J, Cyinski J B, Parker B, Marks T, Feldman M, Lorenz RR  who appear to have the record for a published and peer reviewed case of Super Obese Airway management.

       This massive 22 year old individual required a tracheostomy for hypercarbia with failed  CPAP therapy was reported in the Journal of Clinical Anesthesia : 2007;19:367-369. 

       The management was carried out by an awake approach with , first an attempt at awake flexible Fiberoptic endotracheal tube placement , which failed to achieve the safe advancement of the endotracheal tube. This failure was caused by poor patient compliance and epistaxis. Then a size 5 Proseal Laryngeal Mask Airway was placed successfully and provided a passage way for a Flexible scope passage with an Aintree exchange catheter loaded on to it. The flexible scope was then removed and the 7.5 mm I.D. endotracheal tube  was then passed over the Aintree catheter by a "railroading" technique. 

       The GlideScope was not attempted in this individual so its possible utility is not determined. GlideScope use in Massive obesity has been reported by Dr. John Doyle elsewhere .

GlideScope Obesity Record BMI - 125 . Report from SAM FORUM Feb 13, 2015

GlideScope Intubation of Patient with BMI 125 - Denver Colorado

The SAM forum has recently had an unofficial challenge series describing High BMI individuals treated by SAM members. The Patients included :

1. The Key Case posted by Felipe Urdaneta was a Thyroidectomy case booked for a Thyroidectomy , possible neck dissection. This patient was ultimately  intubated using an awake flexible scope technique . The patient was extubated with Remifentanil drip sedation. The patient became confused enough to break the special service Bariatric bed but survived the event.

2. Richard Shockley recollected a case with a BMI 99.

3. The Record Case so far was reported by Sara Cheng MD , Denver Colorado.

Sara was in her first Post Residency year, when she was called to MICU for a stat intubation at 4AM. The super obese patient  had deteriorated under BiPap to a PACO 2  of  100 . 

This hypercapnia was causing CO2 Narcosis.

The BMI calculated to be 125.

The patient was intubated sitting up with Sara Cheng in front of the patient using a GlideScope 

No additional Medication was used.

This technique has been called the Tomahawk Procedure .

GlideScope "Tomahawk"  Technique

1. Patient in a sitting position,  laying on the side , or supine.
2. Pacey Topicalization Technique ---2% Lidocaine Gel / 2% Lidocaine liquid mixture. 3 way stopcock and 2- 10 cc syringes used to mix 15 cc total volume with some air to create foam.
3. Deliver Foam to the oropharynx where it will spread throughout the pharynx.
4. Invert the GlideScope screen so that right and left sides are correct.
5. Hold the GlideScope like a Tomahawk in the Right hand
6. Use a Verathon rigid stylet and an appropriate size tube- consider a Parker tube if available.
7. Introduce the GlideScope but, as always do not insert it too far or lift too vigorously.
8. Introduce the ETT and extract the stylet as the tube tip passes the cords .

#2 EMS Airway : GlideScope from 61% DL to 96% GVL after manikin training- Dr Rothfield

#1 EMS Airway Management- The largest opportunity to improve airway care.

Advanced airway management is necessary in prehospital trauma patients

1. D. J. Lockey1,2,*, 
2. B. Healey1, 
3. K. Crewdson1, 
4. G. Chalk1, 
5. A. E. Weaver1 and 
6. G. E. Davies1

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1. ↵*Corresponding author. E-mail: david.lockey@nbt.nhs.uk

1. ¹Institute of Pre-hospital Care, London's Air Ambulance, London E1 1BB, UK
2. ²School of Clinical Sciences, University of Bristol, Bristol BS8 1TH, UK

• Background Treatment of airway compromise in trauma patients is a priority. Basic airway management is provided by all emergency personnel, but the requirement for on-scene advanced airway management is controversial. We attempted to establish the demand for on-scene advanced airway interventions. Trauma patients managed with standard UK paramedic airway interventions were assessed to determine whether airway compromise had been effectively treated or whether more advanced airway management was required.

Methods A prospective observational study was conducted to identify trauma patients requiring prehospital advanced airway management attended by a doctor–paramedic team. The team assessed and documented airway compromise on arrival, interventions performed before and after their arrival, and their impact on airway compromise.

Results Four hundred and seventy-two patients required advanced airway intervention and received 925 airway interventions by ground-based paramedics. Two hundred and sixty-nine patients (57%) still had airway compromise on arrival of the enhanced care team; no oxygen had been administered to 52 patients (11%). There were 45 attempted intubations by ground paramedics with a 64% success rate and 11% unrecognized oesophageal intubation rate. Doctor–paramedic teams delivering prehospital anaesthesia achieved definitive airway management for all patients.

Conclusions A significant proportion of severely injured trauma patients required advanced airway interventions to effectively treat airway compromise. Standard ambulance service interventions were only effective for a proportion of patients, but might not have always been applied appropriately. Complications of advanced airway management occurred in both provider groups, but failed intubation and unrecognized oesophageal intubation were a particular problem in the paramedic intubation group.

                                   Telemedicine Strategies Advancing

The world is leading toward more and more connectedness and the potential to extend the footprint of very knowledgeable people is great as tele systems gather strength. The use of commercially available I Phones and FaceTime for Medical consultation was first reported for Airway Management by Dr John Sakles and Dr Jarrod Mosier from the University of Arizona . (Telebation : Next-Generation telemedicine in remote airway management using current wireless technologies. Telemed J E health 2013,Feb 19,(2): 95-8.)

This new study from Japan extends this theme

A pilot study of tele-anaesthesia by virtual private network between an island hospital and a mainland hospital in Japan

1. Tetsuya Miyashita, Yusuke Mizuno,Yo Sugawara, Yusuka Nagamine, Yukihide Koyama
2. Tomoyuki Miyazaki, Kazuhiro Uchimoto, Yasuhiro Iketani, Kentaro Tojo, Takahisa Goto.

1. Department of Anesthesiology, Yokohama City University Hospital, Japan

1. Dr Tetsuya Miyashita, Department of Anesthesiology, Yokohama City University Hospital, 3-9 Fukuura, Kanazawa-ku, Yokohama City, Kanagawa 236-0004, Japan. Email: yushukyo@gmail.com

We studied the use of tele-anaesthesia between Sado General Hospital (SGH) located on Sado Island and Yokohama City University Hospital (YCUH) located in mainland Japan. The two sites were connected via a virtual private network (VPN). We investigated the relationship between the bandwidth of the VPN and both the frame rate and the delay time of the tele-anaesthesia monitoring system. The tool used for communication between the two hospitals was free videoconferencing software (FaceTime), which can be used over Wi-Fi connections. We also investigated the accuracy of the commands given during teleanaesthesia: any commands from the anaesthetist at the YCUH that were not carried out for any reason, were recorded in the anaesthetic records at the SGH. The original frame rate and data rate at the SGH were 5 fps and approximately 18 Mbit/s, respectively. The frame rate at the transmission speeds of 1, 5 and 20 Mbit/s was 0.6, 1.6 and 5.0 fps, respectively. The corresponding delay time was 12.2, 4.9 and 0.7 s. Twenty-five adult patients were enrolled in the study and tele-anaesthesia was performed. The total duration of anaesthesia was 37 hours. All 888 anaesthetic commands were completed. There were 7 FaceTime disconnections, which lasted for 10 min altogether. Because no commands needed to be given during the FaceTime disconnection, the telephone was not used. The anaesthesia assistance system might form part of the solution to medical resource shortages.

• Accepted September 26, 2014.