Combined Video Laryngoscopy, Nasal O2, and Nasal Bougie Intubation

Brazil - Your First Nasal Bougie You will Never Forget.

  Credit - SAM Clinical Forum

The combined use of Video Laryngoscopy with other advanced Procedures is well established and can create a powerful strategy with much improved safety.
Dr Marcelo Ramos , Dec. 11 , advanced the art by posting a combined Technique.

1. Patient with predicted difficult airway   BMI 32, TMD 5 cm, upper incisors 3 cm forward of inferior,  MP 4,
2. Nasal Oxygen was used
3. A highly angled video Laryngoscope was able to view the Glottic opening
4. Placement of a nasal bougie was possible under direct vision.
5. Endotracheal tube was threaded over the Bougie.

Discussion:
1. Nasal Oxygen is highly desirable to produce the oxygenation safety boost and there are 3 methods  available.  1.Nasal prongs with a maximum flush. 2. Thrive high volume (up to 70 L per minute) humidified high flow nasal O2 which can give prolonged apnoea oxygenation (Patel , BMJ 2015 vol 70 3, pg. 323-329. ) or Nasal CPAP (TSE PAP) using a nasal CPAP mask as per Dr James Tse.
2. The highly angled VL is essential for these cases.
3. Bougie or FOB may be used to guide the ETT via the nasal or oral route.

Elegant technique by an excellent Brazilian team - Congratulations.

Airway Culture - UK Airway Lead Concept -Alistair McNarry (Edinburgh)

Society For Airway Management 2016

"any process that is measured will improve"

Medical education and practice culture .

 1. The tools available for  airway management continue to improve annually and have now reached a stage of development that permits excellence in care of normal and difficult airways.

2. The Human Factors and Culture have become the critical area for improvement. If one has a plan that includes available tools, a knowledge of the patient variables, skill in selecting and applying the tools should virtually always produce a desirable result.

3. There remains a disturbing variation in the availability of equipment and skill applied in various hospitals and regions.

4. As the understanding of our art improves it is imperative that we develop a more orderly way of applying it.

The UK "Airway Lead" Concept.

The development of a systems approach in the UK is very instructive. The recognition of serious problems in difficult airway management resulted in assembly of a highly motivated team of investigators who produced a National study document - NAP4- which investigated the scope of unfortunate events and propelled changes. This ultimately was distilled into the  

Difficult Airway Society 2015 guidelines for

management of unanticipated difficult intubation

in adults.     

 British Journal of Anaesthesia, 115 (6): 827–48 (2015)

       The Problem: How to propel the change into the entire NHS System?

The "National Airway Lead"- Alistair McNarry

To organize the knowledge rollout a National Airway Lead was appointed with a goal of developing local Hospital Airway Leads whose mission is to :

1. Identify and master the changes that are evolving.

2. Identify the essential tools to make excellence possible.

3. Develop a local airway culture.

4. Measure and adapt local results.

The British example is extremely well conceived and in my view should be embraced to produce  a culture of excellence proven by measurement. Haphazard approaches will not produce the kind of changes that we need.

As my Engineering friends remind me: 

"any process that is measured will improve" 

Nasal Tse PAP -the next big thing in Anesthesiology

The Emergence of Nasal Tse-PAP 

     The tools available for the practice of Anesthesiology have been growing in number recently and it is now clear that the pace has been too fast for the Medical Profession to step up and adopt them. Such is the case with Nasal CPAP which I have renamed for Branding purposes as Nasal Tse-PAP in honour of Dr James Tse , who has been striving to teach the profession the great benefits of this technology. James has won important prizes and has greatly expanded the clinical experience with this technology.

     The contribution possible from nasal routes is being recognized by leaders in airway management thinking and might be summarized as falling into 4 general Groups in ascending order of effectiveness:

  1. Nasal Airway- alternate method of dealing with transient upper airway obstruction.

  2. Nasal Prongs- low flow transition for supplementary oxygen.

  3. HFNO - High Flow Nasal Oxygen -typified by the Vapotherm (R) which delivers 40 L/min or Optiflow(R) 1. which can deliver up to 70 L humidified oxygenated air to the pharynx via a nasal apparatus. This extremely effective strategy will save many lives by at once causing great turbulence , high oxygen availability for apnoeic Oxygenation, and a degree of CPAP.

4. Nasal TsePAP - this strategy promoted for many years by Dr James Tse from Rutger's University  has demonstrated the elegant and highly effective use of a Prediatric facemask , slightly modified , to generate nasal pressure as an induction strategy or as a rescue method. The ease of ventilation of a large range of patients (Obesity, Pediatric, Procedural MRI CT, and importantly as a transition to Intubation using a highly angled Video Laryngoscope like the GlideScope.

The advantages of this method include the use in bearded patients and use in patients having failed facemark ventilation. The nasal Tse PAP method pressurizes the nasal channels and tends to push the soft palate , tongue forward while delivering positive pressure and peep effects. This great work has been presented  at ASA, SAM, PGA, and internationally for many years. Patient safety Prize  has been awarded to Dr Tse for his work.

                CT Nasal Tse PAP in use - positive pressure can be added any time that the clinical situation requires it. The comfort of the apparatus is suited to long term application.

Dr Tse demonstrating the transition from Nasal Tse PAP to GlideScope intubation with out removal of the Nasal Tse PAP mask. The oxygenation continues at all stages of the procedure.

Nasal Tse Pap paediatric size 2 mask in place during care for a bearded patient cared for by Dr Tse at Robert Wood Johnson University Hospital. The ability to easily ventilate many patients with difficult face mask ventilation using a Nasal mask is important. The ability to deliver positive pressure easily ,as required , during procedures like MRI is also a good contribution to patient safety.

Nasal Tse PAP Apparatus - Dr James Tse - including attached oral CO2 monitor channel. Transition to positive pressure ventilation is done without changing the equipment and by preventing oral leakage of gas. 

Summary:
Nasal Strategies for ventilation are proven to add to patient safety and this has been recognized widely . Adoption has lagged and it is time that the Anesthesiology world quickly moved to catch up to the technical advances developed by Dr Tse and others.
Key Nasal rescue strategies are possible and are gaining recognition.


COI.
   I , as Glidescope Inventor and Consultant to Rutgers University must disclose a conflict of interest on this topic, having a minor interest in Nasal Tse PAP success.

1. Patel Anaesthesia 2015, 70, 323–329

The Emergence of the vomiting Manikin - SALAD - Suction Assisted Laryngoscopic Airway Decontamination.

                                                     SALAD TRAINING

 The development of simulation centres has improved the level of teaching available in Surgery and also Anesthesia. There are 2 steps involved in this innovation: First to expose students of all experience levels to consistent training scenarios. then Secondly to begin testing retention of material known to be necessary for competent application.

      Specific problems are identified such as difficult airway , airway fires, equipment malfunction and  other "imagined difficulties" and then a teaching approach is constructed to teach management.  The development of vomiting during attempts to intubate is one of the most challenging events one can encounter. The vomiting manikin  recently popularized by great airway innovator from Milwaukee Dr Jim Ducanto  and by Dr Yen Chow of Thunder Bay EMS service is a remarkable addition to simulation centre teaching capability.

     Using these manikins  is surprisingly instructive because one can learn to aggressively attack the appearance of vomitus and control the situation quickly  to avert disaster. The first realization is that quick action is effective, the rapid suctioning followed by placing the suction on the left side of the laryngoscope can permit one to focus on getting the view and then placing an endotracheal tube. The Video Laryngoscope is effective in these situations because the elevation of the tongue allows fluids to collect in the back of the pharynx whereas the direct laryngoscope creates a channel that narrows as it gets closer to the larynx with the result that fluids collect at the critical spot essential for visualization. Many opinions will emerge on this point but I am confident that Video will prevail. This is apparent with the vomikin manikins.

1. The vomiting Manikin pump and reservoir in place prior to teaching.

2. The Clinical setup with the emergence of Pseudo Vomit.

3. The fluid challenge is seen with a suction in place on the left side of the mouth while the VL and tube are utilized. The continuous suction maintains a dry field.

Measurement of the 60 degree angle of the Glidescope Blade.

                                                   GlideScope Blade Angle
The measurement of the blade angle that is the key to success of the GlideScope Blade in management of Difficult Airway patients is carried out by comparison of what one sees when looking directly into the mouth when the GlideScope is inserted. Early experimentation clearly demonstrated that to get the 99.9% working view of the airway ( GSCL Grade 1 or 2 View ) it was necessary  to have a 60 degree angle . Lesser angles were shown clinically to be unable to get a working view in a few % of patients. The mission of the inventor was to provide a GSCL view that would permit intubation in 99.9 % of patients with the theory that if you could see it you could place the tube successfully.

Experience has shown that those users who used the GlideScope regularly could virtually always deliver the tube (especially with the highly controllable Verathon (Pacey) rigid steel stylet. Those who did not practice with the device sometimes failed to advance the ETT and blamed the tool for their performance. Because we have a large number of users who can always advance the tube when they get a good view we believe the tool is not the problem.

                                                    GSCL      Grades 1-4
Notes with respect to the Cormack - Lehane views are not relevant to video laryngoscopy and therefore I use the GSCL scale which is simply the GlideScope Cormack Lehane view scale. Because each device has its own performance characteristics this becomes relevant when transmitting patient information to future caregivers.

                                       Calculation of the 60 degree angle:
The black arrow is the line of sight when the GlideScope is inserted into the mouth.
The 60 Degree angle is thus measured.

Telemedicine -Assisted Intubation In Rural Emergency Departments: A National Emergency Airway Registry Study

Comment: This Database Study is very important as a harbinger of the future that we are about to see . The tools for excellence in airway management are now available and the future depends on the development of an airway culture that elevates the professions use of these tools. 

 Telemedicine -Assisted Intubation In Rural Emergency Departments: A National Emergency Airway Registry Study

Lucas Van Oeveren, MD,1,2  Julie Donner, MS,2

 Andrea Fantegrossi, MPH,3  Nicholas M. Mohr, MD, MS,4,5

 and Calvin A. Brown III, MD3,6

1 Section of Emergency Medicine, Avera McKennan Hospital,

Sioux Falls, South Dakota.

2 Avera eCARE, Avera Health System, Sioux Falls, South Dakota.

3 Department of Emergency Medicine, Brigham and Women’s

Hospital, Boston, Massachusetts.

4 Department of Emergency Medicine, Division of Critical Care,

and 5 Department of Anesthesia, University of Iowa Carver

College of Medicine, Iowa City, Iowa.

6 Harvard Medical School, Boston, Massachusetts.

Abstract
Background: Intubation in rural emergency departments (EDs)
is a high-risk procedure, often with little or no specialty support.
Rural EDs are utilizing real-time telemedicine links,
connecting providers to an ED physician who may provide
clinical guidance. Introduction: We endeavored to describe
telemedicine-assisted intubation in rural EDs that are served by
an ED telemedicine network. 

Materials and Methods: 

Prospective data were collected on all patients who had an intubation attempt while on the video telemedicine link from May
1, 2014 to April 30, 2015. We report demographic information,
indication, methods, number of attempts, operator characteristics,
telemedicine involvement/intervention, adverse
events, and clinical outcome by using descriptive statistics.
Results: Included were 206 intubations. The most common
indication for intubation was respiratory failure. First-pass
success rate (postactivation) was 71%, and 96% were eventually
intubated. Most attempts (66%) used rapid-sequence
intubation. Fifty-four percent of first attempts used video laryngoscopy
(VL). Telemedicine providers intervened in 24%,
43%, and 55% of first–third attempts, respectively. First-pass
success with VL and direct laryngoscopy was equivalent (70%
vs. 71%, p = 0.802). Adverse events were reported in 49 cases
(24%), which were most frequently hypoxemia. 

Discussion:

The impact of telemedicine during emergency intubation is not
defined. We showed a 71% first-pass rate post-telemedicine
linkage (70% of cases had a previous attempt). Our ultimate
success rate was 96%, similar to that in large-center studies.
Telemedicine support may contribute to success.

Conclusions:

Telemedicine-supported endotracheal intubation performed in
rural hospitals is feasible, with good success rates. Future research
is required to better define the impact of telemedicine
providers on emergency airway management.
Keywords: telemedicine, emergency medicine, teletrauma,
telehealth, e-health
Introduction

Pacey's Paste Method of Application Local Anesthesia to the Pharynx, and Glottis.

                               Pacey's Paste for Easy Topicalization of the Upper Airway.

There are numerous invasive and non-invasive methods of application of Local Anesthesia to the OroPharynx and Glottis and all of these have their devotee's. The classic methods use a nebulizer with a bulb attached and spray Novocaine or local mixed with Epinephrine through a stiff metal wand as you go into the airway.

There are Xylocaine Pressurized spray devices available as well but often the spray via a flexible and breakable plastic wand as well. These are often used for spraying cords during induction where a Direct Laryngoscope is being used.

The failure of these methods is most pronounced when you need them most in the challenging difficult airway scenario. Failure leads to spotty application which is most heavily applied in the oropharynx and tongue but is less efficiently applied in the hypo pharynx area. The result of this distribution is that when  tools get close to the Glottis the patient may respond with reflex protective neck muscle activation and a battle can then ensue between the determined airway manager and the equally determined distressed patient.

Strategies designed to avoid maldistribution of Local anesthetic.

The MAD ( Mucosal Atomizer Device) Device is an attempt to avoid maldistribution by use of a flexible wand that can pass down in the awake patient into the hypo-pharynx closer to the area of need. This device has many devotees and has become more popular recently.

Direct placement of local by a trans-cricothyroid membrane route has also been done to at once identify this membrane and the trachea while it also applies local anesthetic to the cord region and perhaps also the Glottic entrance such that it may suppress laryngo-spasm or discomfort of tube passage.

Percutaneous injections directed at the Supra-Laryngeal nerve supply of the larynx via bi-lateral infiltration of the neck have also been used at times,  but have several problems. Hitting the target can be challenging in the more obese patient, where the need is great, because the greater cornua of  the hyoid may be poorly defined. The neck also has tissue planes that channel the injected material in uncertain paths leading to spotty topicalization. The injection of larger amounts of xylocaine and adrenaline can also cause swelling of the peri-glottic tissues which could lead to poorer visualization.

Pacey's Paste Method of disseminated topicalization of the Pharynx and Larynx.

The above methods are in themselves sub optimal and therefore generate consternation and debate about how one may consistently topicalize the area. The method that I learned from an American Anesthesiologist  was ideal for my practice of upper GI endoscopy where passage of a 10-12 mm gastroscope was necessary. Following IV Versed and Small doses of IV fentanyl this method was applied.

The dose was prepared by connection of 2 10 CC syringes to a standard 3 way iv tubing stop cock. Then 7 cc of Viscous 2% Lidocaine and 3 cc air were drawn into one syringe and 7cc of 2% lidocaine with 3 cc air was passed into the second syringe. With the valve turned to allow passage back and forth to these syringes a mixing of the air with these 2 forms of lidocaine was carried out to produce an airway slime that had 14cc of 2% lidocaine content. this was instilled into the mouth in 2 aliquots while other preparations were carried out. After a few minutes this frothy slime could be seen in all recesses of the pharynx and even down to the stomach. The bubbles accumulated in the glottic entrance as well. Thus the even distribution was obvious on each occasion. The gastroscope is a large intrusion device and passage was encouraged by the very slippery slimy bubbles and lidocaine. 

Because I used this regularly in a busy endoscopy practice the efficiency of the method was confirmed. Because this was done in a formal endoscopy clinic the nursing staff were able to set up and mix the solution of air bubbles, Lidocaine Viscous, and  Lidocaine Liquid prior to each case and on occasion  do the topicalization procedure itself.

Success of Intubation Rescue Techniques After Failed Direct Laryngoscopy in Adults: A Retrospective Comparative Analysis From the Multicenter Perioperative Outcomes Group

Aziz MF, Brambrink AM, Healy DW, et al

Anesthesiology. 2016 Aug 1. [Epub ahead of print]

Study Summary

A team of investigators retrospectively analyzed 346,861 anesthesia cases that involved attempted tracheal intubation from 2004 to 2013 at seven academic centers. Of these, 1427 patients (0.41%) had a failed direct laryngoscopy, leading to 1619 subsequent intubation attempts.

The majority of these rescue attempts (69%) were managed with video laryngoscopy, followed in frequency by flexible fiberoptic (11%), lighted stylet (8%), supraglottic airway as part of an exchange technique (5%), or optical stylet (0.6%). More than 1000 anesthesia providers (353 attending anesthesiologists, 449 residents, and 207 certified registered nurse anesthetists) managed these rescues after being unable to intubate the trachea with a traditional laryngoscope.

The study's main take-home message was that video laryngoscopy had the highest intubation success rate (92%), with the GlideScope® (Verathon; Bothell, Washington) the most commonly used video laryngoscope device (89% of the time). The intubation success rate for rescue was 78% for both the supraglottic airway conduit and flexible bronchoscopic intubation, followed by 77% for lighted stylet and 67% for optical stylet.

Viewpoint

Inability to intubate the trachea after induction of general anesthesia is an outcome anesthesiologists aim to avoid. Although there are patient characteristics that can be used to help predict who will have a difficult airway, there is no 100% sensitive or specific prediction tool. As a result, clinicians will encounter unexpectedly difficult airways to intubate, as this study's 0.41% incidence rate suggests. Any study that sheds light on the use and success rates of rescue techniques after failed direct laryngoscopy in adult surgical patients will therefore be priority reading for clinicians.

For the past half-century, the most common method for intubation was to insert a laryngoscope (which consists of a handle and either a curved or straight stainless steel blade with a light source) into the oropharynx, so that the vocal cords are directly visualized. In contrast, the video laryngoscope has a digital camera on the blade. This means that the clinician does not directly view the larynx, but rather sees it indirectly on a screen.

In this study, 89% of rescues used the GlideScope video laryngoscope, which has a different (ie, 60°) angulation of its blade without the usual need for anterior displacement of the lower jaw. This helps improve the view of the larynx, which is projected onto an external liquid crystal display screen mounted on a separate stand.

The authors found that the use of video laryngoscopy for rescue of failed direct laryngoscopy increased from 30% in 2004 to more than 80% in 2012. This is not an unexpected result. As video laryngoscopy technology has become more widely available in surgery suites across the country, anesthesia providers have been able to gain experience and comfort with the available devices.

This study's main finding builds on the growing literature supporting the usefulness of video laryngoscopy in clinical anesthesia care. In fact, the study showed that more than 90% of the time when intubation was not possible with the traditional direct laryngoscope, the newer video laryngoscope proved to be helpful.

The very large sample size of this study (>300,000 cases) is a nice example of the kind of pooled data research made possible by the Multicenter Perioperative Outcomes Group, a consortium of institutions formed in 2008 with a shared data set facilitating the investigation of perioperative outcomes.

It is quite likely that video laryngoscopy devices, with their improved optics, will increasingly replace traditional direct laryngoscopy in routine airway management.

BESTA Airway Algorithm -a modified EGRI- El Ganzouri Risk Index -New Evidence of relevance to Morbid Obesity

The Besta Airway Algorithm
an improved  El Ganzouri Risk Index

The Besta Modification of the El Ganzouri Risk Index has been incorporated in the "Systematic" approach to airway management reported by Dr. Caldiroli and Cortellazzi in Milan Italy as the development of a systematic approach to airway management. ( Minerva Anesth. 2011 oct ,77 (10) , 1011-1017.)

The approach involved getting 13 Anesthesiologists to agree to try to do optimal airway management by using the GlideScope VL for all airway management in a very structured way. The method in short included the following important steps never done before:

Develop a  modified Airway approach with mutually agreed steps.

• Application of a method of airway assessment that incorporated many of the known airway measures, each of which is known to be moderately effective in assessment, into the El Ganzouri Risk Index. This index was developed prior to the GlideScope era but with significant modification was adopted to the BESTA airway Algorithm-  the best available index for the " BESTA Culture and System".

• The scoring system was used as follows:                                                                                                               EGRI Score. plus a number of custom features that modify the BESTA index to make it appropriate to the GlideScope Age.

          BESTA modifications Add the score for each individual indicator to total all and prescribe actions based on the score.

            1-3  Low Risk of Difficult Airway for endotracheal intubation - proceed with GlideScope .

            4-6  significant risk of difficult airway management - proceed with consultation followed by

                   GlideScope intubation. The "Programmed Consultation" is fundamental because it gives
                   the patient the highest chance  of having airway management without injury or failed
                   attempts.

             7   (or higher)   consultation is obtained and alternate awake airway management will
                   be selected either with GlideScope or Flexible Video Endoscopy. Further examination of
                   the airway may be considered with Flexible pre-op endoscopy , CT or MR to be
                   absolutely clear what problems may be encountered.

• The Consultation Process- This is very much like the aviation model where weather or other flight conditions are reviewed Prior to takeoff. Team work is then established as a norm and individual skill or lack of skill is offset by design.

• The Airway management event itself is executed using Equipment that is known to be operational and appropriate.

• The Immediate recording of the airway encounter to provide a database for quality assurance and improvement of the process.

While Dr Caldiroli's initial work was monumental with 6,278 patients managed The BESTA  Neurological Hospital.  Patients with Obesity were excluded from the original study. The results were that 2 were excluded because of local malignancy , 6,270 with BESTA modified EGRI 1-6 were intubated with the Glidescope .  Flexible endoscopy was used on 6 patients with BESTA modified EGRI > 7. This left a gap in the understanding of how Morbidly Obese patients should be managed. This Gap was recently addressed by the  Group from Milan  in a study of 214 patients with Morbid obesity managed by the same method as  Caldiroli Et. Al.  using the BESTA modified EGRI assessment tool.

Surgeons Guide to Airway Management Dr. John Allen Pacey MD , FRCS(c) No.3

If The Tools Exist , How Do We Then Achieve Excellence?

If the tools are now available for Airway Management Excellence then why do we struggle and how should we proceed in a way that will  provide high quality care that is reproducible and measurable .  The goal of this work is to provide a guide for system change and method of measuring the performance of the new process.

The science of change management must be brought to bear on this. Medical change process started perhaps with Fredrick Winslow Taylor who introduced the concept that waste and inefficiency was caused by haphazard unscientific management.  The book 1911 book “The Principles of Scientific Management” was a first attempt to define a science for change. This proved to be an authoritarian approach suited to a society where workers had fewer means of education. Later, Peter Drucker in a prodigious effort well summarized in   2008  , “ The Essential Drucker The Best Of Sixty Years of Peter Drucker’s Essential Writings on Management ” introduced the notion of management of “Knowledge Workers” who have substantial core information that will inform change toward more highly functioning organizations. The notion that organizations trend toward chaos is perhaps pessimistic but is widely believed today.

Modern leaders set a frame work of goals and base rules which allow for distributed leadership of ways and means to get to change on a local basis. This is demonstrated with the new organization of the US Army where the strategy and clear objectives are defined at the center , the Pentagon,  and the assignment of an Expeditionary commander begins a process where the elements required for success (such as IT Support, Transport, Air ) are defined and assigned by the unit who is responsible for execution. This devolution of decision making to those who are answerable for the outcome thus  places the HQ in the position of being the responsible observer monitoring  progress .

The focus for us professionals should be on the individual unit or work space like the OR, ICU or ED and begin to seek ways of achieving perfection that is built on the skills and initiative of the local professionals but is wedded to the IT and management framework and goals for the organization overall. This local initiative produces high energy activity that entrains all of the brilliance available. The trick then for the local change agents must be to have appropriate goals so that the change does not collapse into petty politics and divisions. The energy of a fully engaged community with measurements for results is thus converted into forward action.

The process becomes a big part of the reason for a great or less than great outcome. As stated previously there are many capabilities needed for any professional team so the learning must go on in many directions at the same time. The development of British style “team leads” can be a useful way to start the process .

Professionals in the organization must be taught to become agents for change rather than curmudgeons or foot draggers. The new Systems for quality demand a new set of attitudes geared to embrace real change.

Surgeons Guide to Airway Management Dr John Allen Pacey MD , FRCSc No.2

The Tools For Excellence In Airway Management Are Now Available.

         The last 20 years have provided many new tools for airway management with the result that there are many options now available for management of most anatomical and physiological states. This is not meant to be any kind of complete history of development of useful devices and will not consider, for example, the “Iron Lung” developed for the polio era or many other useful devices.

         The “Big Seven” Airway Tool Strategies include :

1. Direct surgical access. 

2. Facial Masks – Standard Face Mask and Nasal Mask.

3. DL-Direct Laryngoscopy.

4. FOL-Fiberoptic Laryngoscopy.

5. VL-Video Laryngoscopy.

6. Supra-Glottic Airways –LMA , I-GEL , King LT etc.

7. HFN- Hign Flow Nasal (THRIVE) or High Pressure Nasal (NASAL _TSE PAP)

·      The ancient tracheotomy and surgical approach to the airway goes back to Egyptian Medicine circa 3600 BC where tablets have been found with images of tracheal access surgery. The relief of airway obstruction in ancient times was not documented in a way that would allow determination of how many thousand years BC this practice was invented.

·      The cuffed endotracheal tube was invented by Trendelenburg  in approximately 1895 and popularized the development of endotracheal anesthesia that replaced the Ether drop and Chloroform muzzle of earlier days.

·      The vintage 30 degree angulated Direct view Macintosh laryngoscope  1943  with its partner the Direct view Miller Laryngoscope have been the mainstay resources throughout the development of Intubation strategies for Anesthesiology and Emergency Medicine. While these devices were not the first Direct viewing devices they were substantial leaps forward with implementation of a reliable light carried onboard.

·      The development of a fiberoptic endoscope in 1957 with light bundle fiber clusters to carry light to the body interior and then carry an image back to the Medical observer. This led to the first indirect viewing class of endoscopes that proved to be a great advance in capability. These devices were popularized by Andranic Ovassapian who later with friends in the airway community innovated the “Society for Airway Management” designed to develop and foster a culture aimed at solving the difficult airway conundrum.

·      The flexible light fibers and small DC bulbs also permitted development of lighted flexible stylet products , some with viewing capability like the Shikani laryngoscope and others without viewing such as  the Trachlight class of lighted stylets.

·      The development of the Laryngeal Mask Airway concept was innovated by Archie Brain to move the mask seal component from the face where seals could be problematic to the area immediately behind the glottic complex. This strategy was effective and provided a “Plan B “ backup for the cannot intubate cannot ventilate ( CICV) situation that was causing a continuous string of failed airways resulting in patient death and cerebral cell death. Then a prolific period of innovation provided a plethora of SGA (Supra Glottic Airways) that followed the original designs.

·      The invention of the GlideScope Highly Angled CMOS Video Laryngoscope (60 Degree)by Pacey in 2000 provided a new asset for airway managers and proved to be a useful new portable device for hospital and out of hospital use. Storz developed their fiberoptic rigid laryngoscope direct view device by adding a video camera in the handle. Later a variety of 60-90 degree rigid video laryngoscopes were introduced by Pentax, McGrath and others.  Some carried display screens on the handle while Saturn introduced the rugged compact 1.5 lb. water proof  USAF inspired Ranger for Military and Civil EMS application. Verathon subsequently has developed and marketed in excess of 30 variants of the original GlideScope. The video laryngoscope has subsequently earned a place in the DAS 2015 and ASA 2013 difficult airway guidelines where its use may be implemented as a first attempt device or at many stages in the decision making tree.

·       Surgical kits designed to gain access to the trachea used the Seldinger strategy with guide wires and even ultrasound guidance to aid the user. A series of dilating devices like the “ Blue Rhino” became common for ICU tracheostomy to elegantly wean ventilated patients.

The field use of these surgical kits proved to be less satisfactory because usually the application of these kits was carried out too late at a time when the patient was in an extreme pre- arrest state. The US Army had a disappointing legacy with these devices because of the training gap that exists for a device or system that requires a significant judgement level for optimal application.

·       Nasal strategies are now the most quickly developing  approaches to attack the problem of inadequate ventilation prior to intubation. The initial work was done using normal flow nasal prongs to augment the standard 4 minute BVM preoxygenation . Then higher flows were used to provide a flush during intubation and mixed results were obtained but these efforts were encouraging in some patients. The goal is to increase the period of sustained oxygenation and slow the deterioration on the classic curve of Benumof which shows the minutes to desaturation for Obese, Normal 10 Kg. Child , Moderately ill Adult, Normal 70 Kg. Adult .

The evolution in Nasal Oxygen delivery has progressed to the delivery of up to 70 L/min. of HFNO (High Flow Nasal Oxygen) via the proprietary  THRIVE device from Australia which can deliver humidified high flow Nasal O2 and result in a defacto Nasal CPAP where the flow is so high that continuous positive pressure exists. This high flow is in effect providing CPAP and apneic oxygenation with the attendant expenditure of copious amounts of oxygen. ( 40-70L/min.) This use of oxygen could be a problem for prehospital transfer or forward military sites  where  oxygen supplies are less plentiful.

Dr James Tse has taken another tack with nasal TSE PAP which involves using a Pediatric size 2 oro-nasal mask  which is applied to the nose of an adult and used to create Nasal CPAP which acts by opening the Nares, Displacing the soft palate forward against the tongue, avoidance of posterior displacement of the Jaw and tongue, and finally administration of a positive pressure throughout the respiratory cycle. This has been shown to be superior to the classic  Facial mask which applies pressure to the jaw and mouth area forcing the jaw back and the posterior aspect of the tongue against the posterior wall of the pharynx.

         The mask can be in position throughout the intubation process as well with the effect that the only time that TsePAP is not providing positive pressure is during actual laryngoscopic opening of the oropharynx. During this reduction in pressure the nasal oxygen continues to flow providing an oxygen rich environment down to the Glottis and to alveoli that have just recently been opened by the TsePAP effect. The net result is that it is uncommon to have oxygen saturation below 100 % even when various manouvers have been executed.  The consumption of oxygen with TsePAP is more in the range of 5-10 L/min.

Figure. 1 Time in minutes to precipitous desaturation of oxygen in the blood for (Left to Right) obesity , 10 Kg. Child , & 70 Kg. moderately ill Adult, and Normal Adult  .