HIGH FLOW NASAL OXYGEN: AN ANESTHESIA GAME-CHANGER

Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group
Richard Novak, MD is a Stanford physician board certified in anesthesiology and internal medicine.Dr. Novak is an Adjunct Clinical Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Stanford University, the Medical Director at Waverley Surgery Center in Palo Alto, California, and a member of the Associated Anesthesiologists Medical Group in Palo Alto, California.
emailrjnov@yahoo.com
THE ANESTHESIA CONSULTANT

At the 2023 American Society of Anesthesiologists meeting in San Francisco, I walked by a booth advertising High Flow Nasal Oxygen. The product was called Optiflow. I asked the representative to educate me. She began by opening a package containing an Optiflow nasal cannula, and she strapped it around my head and into my nostrils. Within one minute she started a flow of 40 liters per minute of humidified, warmed 100% oxygen into my nose. I felt a slight sensation of moving air, but because the flow was humidified and warm, I felt no caustic insult of gas blasting through my nose and upper airway. I was—in a word—flabbergasted. The capacity to deliver this much oxygen to a non-intubated patient is a marked advance in anesthesia care.

HFNO was originally used in neonatal and pediatric ICUs to oxygenate acute hypoxemic respiratory failure patients without utilizing an endotracheal tube. Its use expanded to adult ICUs. The ability to deliver 60 to 70 liters per minute of oxygen via the nose enabled physicians to delay or avoid intubating ICU patients with hypoxemia. HFNO is delivered via nasal prongs which are larger than conventional nasal cannula prongs, and at higher flow rates than are generally applied during conventional oxygen therapy. Inspired oxygen/air is heated to 37 °C, and is humidified to 100% relative humidity.

A typical nasal oxygen cannula is limited to supplying 6 liters per minute of oxygen, which is approximately equivalent to delivering 45% oxygen. Using a typical nasal oxygen cannula at a flow higher than 6 liters will cause a patient significant irritation and drying of the nasal mucosa.  By humidifying and heating the oxygen inflow, HFNO can deliver 100% oxygen at a flow rate of up to 60 liters per minute via heated tubing and wide-bore nasal prongs.

 

 

Optiflow Airvo 2 high-flow nasal oxygen device: (1) wire-heated circuit tubing; (2) hot plate-heated humidification chamber system; (3) nasal cannula; (4) oxygen inlet port; (5) sterile water supply.

 

One day after attending the ASA meeting in San Francisco, I heard an in-person lecture in Palo Alto, California by Professor Anil Patel from the Royal National Throat, Nose and Ear Hospital in London. Dr. Patel has been a pioneer in bringing HFNO/THRIVE from the ICU into the operating room. Dr. Patel is the author of a seminal THRIVE (Transnasal Humidified Rapid-Insufflation Ventilatory Exchange ) study, in which he wrote that THRIVE “has the potential to transform the practice of anesthesia by changing the nature of securing a definitive airway in emergency and difficult intubations from a pressured stop–start process to a smooth and unhurried undertaking.

Patel’s landmark 2015 publication “Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE): a physiological method of increasing apnea time in patients with difficult airways” demonstrated that High Flow Nasal Oxygen (HFNO), or THRIVE, “combines the benefits of ‘classical’ apneic oxygenation with continuous positive airway pressure and gaseous exchange through flow-dependent dead space flushing. We extended the apnea times of 25 patients with difficult airways who were undergoing general anesthesia for hypopharyngeal or laryngotracheal surgery. This was achieved through continuous delivery of transnasal high-flow humidified oxygen, initially to provide pre-oxygenation, and continuing as post-oxygenation during intravenous induction of anesthesia and neuromuscular blockade until a definitive airway was secured. Apnea time commenced at administration of neuromuscular blockade and ended with commencement of jet ventilation, positive-pressure ventilation or recommencement of spontaneous ventilation. During this time, upper airway patency was maintained with jaw-thrust. Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) was used in 15 males and 10 females. Mean (SD [range]) age at treatment was 49 (15 [25–81]) years. The median (IQR [range]) Mallampati grade was 3 (2–3 [2–4]), and direct laryngoscopy grade was 3 (3–3 [2–4]). There were 12 obese patients and nine patients were stridulous. The median apnea time was 14 (9–19 [5–65]) minutes. No patient experienced arterial desaturation < 90%.(bold emphasis added by me.)

Figure 2 from this study shows the stability of O2 saturation during the prolonged apnea:

Figure 3 from this study shows the stability of end-tidal CO2 levels during the prolonged apnea, with an average rate of carbon dioxide rise of only 1.1 mm Hg per minute.

HFNO can generate a low level of positive pressure in the upper airway, directly proportional to the high gas flow delivered, probably improving oxygenation by PEEP (positive end-expiratory pressure). This PEEP effect improves alveolar recruitment, and might also improve gas exchange.

Widespread adoption of HFNO as routine therapy in the operating room is still lacking. The main textbook in our specialty, Miller’s Anesthesia, 9th Edition, describes the use of THRIVE for difficult intubations, but their coverage is limited to one paragraph in a chapter on Adult Airway Management, in a section describing Apneic Oxygenation, out of the 3112 pages in the publication.

Many clinicians are simply not aware the technology exists or that it is available.  I believe many smaller hospitals and outpatient facilities such as ambulatory surgery centers do not own the required equipment. The cost of using HFNO exceeds the cost of standard nasal cannulae, but  the cost is not prohibitive. One Optiflow oxygenation+humidification unit made by F & P Healthcare sells for about $1500. The disposable nasal tubing apparatus for one patient sells for about $35.

Important uses of HFNO in perioperative medicine will include : a) keeping a difficult airway patient oxygenated while the anesthesia provider is performing intubation or airway procedures; and b) keeping morbidly obese patients or patients with hypoxemic cardiopulmonary disease oxygenated for brief procedures without needing to place an endotracheal tube or a laryngeal mask airway (LMA).

Let’s look at two demonstrative examples:

High Flow Nasal Oxygen utilized during difficult intubation

 

  • A 53-year-old patient with a difficult airway presents for general anesthesia for bariatric surgery. The patient weighs 350 pounds, stands 5 feet 8 inches tall, and has a Body Mass Index of 53, classifying him as super morbidly obese. His airway exam shows a thick neck (circumference 42 cm, or 16.5 inches), a small mouth, a Mallampati 4 classification, and limited neck extension. You apply HFNO with 100% oxygen at 60 liters per minute, and continue this for 10 minutes prior to inducing anesthesia with propofol and rocuronium. Once the patient is unconscious, you attempt intubation with a Glidescope, and have difficulty visualizing the vocal cords. A colleague assists you by advancing an endotracheal tube threaded over a fiberoptic laryngoscope, while you hold the Glidescope in place. After 14 minutes of apnea time, your colleague is able to advance the fiberoptic scope into the trachea and slide the endotracheal tube past the vocal cords. During all this time the patient was apneic but remained well oxygenated with a saturation nadir of 97% because of the HFNO.
  • A 40-year-old patient presents for an upper GI endoscopy under intravenous sedation. The patient weighs 275 pounds and stands 5 feet 5 inches tall, for a BMI = 45. His airway exam is Mallampati 2. His abdomen is protuberant, and you’re concerned this morbidly obese patient will become hypoxemic under propofol sedation. You connect the patient to HFNO with 100% oxygen at 60 liters per minute for 5 minutes, and then position the patient in the lateral position, left side down. His oxygen saturation is 100%, and you begin a propofol infusion. The patient’s breathing becomes shallower as he loses consciousness, but his oxygen saturation remains 100% as the GI doctor inserts the endoscope into her mouth and completes the procedure. Once the gastroenterologist is finished, you turn off the propofol, the patient awakens, and you bring him to the Post Anesthesia Care Unit where he is stable until discharge.

Upper GI Endoscopy with Optiflow High Flow Nasal Oxygen

 

Currently the American Society of Anesthesiologists (ASA) Difficult Airway Algorithm states, “Recommend supplemental oxygen administration before initiating and throughout difficult airway management, including the extubation process.” There is no specific mention of High Flow Nasal Oxygen (HFNO) or Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE), but the most effective way to administer supplemental oxygen during difficult airway management, without interfering with efforts to manage the airway, is High Flow Nasal Oxygen (HFNO) or Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE).

I believe a statement that High Flow Nasal Oxygen (HFNO) or Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) is a standard of care in perioperative airway management is, in all likelihood, coming in the very near future. The benefit/risk ration of utilizing High Flow Nasal Oxygen (HFNO) or Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) is very high.

I’d suggest you contact a manufacturer of High Flow Nasal Oxygen (HFNO) equipment such as the Optiflow unit,  and look into obtaining this useful adjunct for your facilities.

Disclaimer: I have no financial ties to the manufacturers of Optiflow, nor do I have any financial incentive for recommending their product. I simply want safer care for patients everywhere.

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The most popular posts for laypeople on The Anesthesia Consultant include: How Long Will It Take To Wake Up From General Anesthesia? Why Did Take Me So Long To Wake From General Anesthesia? Will I Have a Breathing Tube During Anesthesia? What Are the Common Anesthesia Medications? How Safe is Anesthesia in the 21st Century? Will I Be Nauseated After General Anesthesia? What Are the Anesthesia Risks For Children?

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READ ABOUT RICK NOVAK’S FICTION WRITING AT RICK NOVAK.COM

INCREASED DOLLAR COSTS ASSOCIATED WITH DIFFICULT INTUBATION

Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group
Richard Novak, MD is a Stanford physician board certified in anesthesiology and internal medicine.Dr. Novak is an Adjunct Clinical Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Stanford University, the Medical Director at Waverley Surgery Center in Palo Alto, California, and a member of the Associated Anesthesiologists Medical Group in Palo Alto, California.
emailrjnov@yahoo.com
THE ANESTHESIA CONSULTANT

The safe management of a difficult airway is the most important single skill for an anesthesiologist. Every critically ill patient is managed by the priority of A – B – C, or Airway – Breathing – Circulation. Just as the initial most important factors in real estate are location, location, location, the three initial important factors in a critically ill patient are airway, airway, airway. I’ve written previously on the American Society of Anesthesiologists 2022 modifications to their Difficult Airway Algorithm, on the importance of expert airway management, and on advice for avoiding lost airway lawsuits, but I haven’t discussed the economic consequences of each difficult airway patient.

A 2021 publication, “Factors and Economic Outcomes Associated with Documented Difficult Intubation in the United States,”  by Moucharite et al, studied the economic cost of a difficult intubation in hospitalized patients. Using data from the Premier Healthcare Database, the study looked at adult patients with inpatient surgical admissions during 2016, 2017, and 2018. Patients in the difficult intubation group had average inpatient costs $14,468 higher than patients without difficult intubations. Patients in the difficult intubation group had average ICU (intensive care unit) costs $4,029 higher than patients without difficult intubations. For difficult intubation patients the mean hospital length of stay was 3.8 days longer and ICU length of stay was 2.0 days longer. All data were significant to a p value of < 0.0001.

In California where I practice, these numbers would be significantly higher. The mean cost of a single hospital day in California is $4181, and the mean cost of an ICU day is significantly higher.

The Moucharite study was a large retrospective review of 2,233,751 cases from hospitals in all parts of the United States. With 609 cases in the difficult intubation group and 2,233,142 cases in the non-difficult intubation group, the incidence of difficult intubation was only 0.027%. Difficult intubation patients were more likely be male, black, less than 65 years old, and have urgent or emergent admissions, obesity, cancer, congestive heart failure, COPD, renal disease, and had been treated in a teaching hospital or a hospital of 500 beds or more.

Moucharite wrote, “Difficult intubation has been associated with a variety of complications including oxygen desaturation, hypertension, dental damage, admission to the intensive care unit, and complications at extubation, as well as arrhythmias, bronchospasm, airway trauma, CICV (can’t intubate, can’t ventilate), and sequela of hypoxia (cardiac arrest, brain damage, and death). This was consistent with a 2011 study of difficult airways from the British Journal of Anesthesia which stated, “Obesity markedly increases risk of airway complications. Pulmonary aspiration remains the leading cause of airway-related anesthetic deaths. . . . Unrecognized esophageal intubation is not of only historical interest and is entirely avoidable. . . . prediction scores are rather poor, so many failures are unanticipated . . . the first-pass success rate of intubation in the operating room ranges from only 63% to 85% . . . and up to 93% of difficult intubations are unanticipated.”

The Moucharite study has limitations. It’s a retrospective study of economic Big Data, and there is no direct evidence for a cause-and-effect relationship between a difficult intubation and a more costly hospitalization. The study does not include data from electronic medical records, so we have no knowledge on all the comorbidities and complications of the difficult intubation patients. The study included only hospitalized patients, even though seventy percent of surgical procedures in the United States take place in ambulatory surgery centers and offices outside of hospitals. The reported incidence of difficult intubation  is estimated to be 1.5–8.5% of the general population, but in  the Moucharite study only 0.027% of patients were found to have difficult intubation. This discrepancy implies some patients in the Moucharite study were difficult intubations but may have been assigned to the non-difficult intubation cohort.

Note that all three authors of the Moucharite study are employees of Medtronic, a medical device company which manufactures the McGrath videolaryngoscope.

McGRATH VIDEOLARYNGOSCOPE

I expect Medtronic could cite the Moucharite study as evidence that a videolaryngoscope (such as a McGrath) is a crucial piece of equipment for avoiding expensive difficult intubation outcomes. Moucharite wrote that there is, “a need for clinicians who perform tracheal intubations to carefully consider options . . . several studies demonstrated the benefits of videolaryngoscopy [emphasis added] including a shorter time required for tracheal intubation, a higher rate of successful intubations.”

For the first look when intubating a patient, most anesthesia providers still use a traditional direct laryngoscope:

MAC 3 DIRECT LARYNGOSCOPE

 

If the direct laryngoscope does not enable a successful intubation, a reasonable second step is to switch to a videolaryngoscope such as the GlideScope, manufactured by Verathon:

GLIDESCOPE

or the C-MAC, manufactured by Karl Storz:

C-MAC

 

or the McGrath, manufactured by Medtronic:

McGRATH VIDEOLARYNGOSCOPE

 

In my experience the larger 6.4-inch screen on a GlideScope or the 5.9-inch screen on a C-MAC makes them superior videolaryngoscopes to the McGrath with its diminutive 2.5-inch screen.

Why use a direct laryngoscope in the initial intubation attempt rather than use a videolaryngoscope? A direct laryngoscope costs less than a videolaryngoscope. Most direct laryngoscopes blades are washed and reused. Videolaryngoscopes require a new disposable sleeve or blade for every case. In facilities with budget concerns, replacing all traditional laryngoscopes with videolaryngoscopes would be expensive. A McGrath costs about $2500 on eBay, and each new nonreusable blade cover costs about $10. A new GlideScope was $12,745 in 2017. A reconditioned GlideScope costs between $1000 and $10,000 on eBay, and each new nonreusable blade costs $38.

A 2022 study comparing direct laryngoscopy to videolaryngoscopy concluded that “videolaryngoscopy likely provides a safer risk profile compared to direct laryngoscopy for all adults undergoing tracheal intubation.” A recent review  stated that, “Though videolaryngoscopes have been recommended for use at first attempt of intubation by most international airway guidelines, the universal use of videolaryngoscopes is still facing hurdles because of limited training opportunities, availability and high cost.”

Should a videolaryngoscope replace a direct laryngoscope for all initial intubation attempts? I don’t think so. The majority of intubations are straightforward and are successful with a Miller 2 or a Mac 3 direct laryngoscope. Should a videolaryngoscope be available as a back-up piece of equipment for every intubation? Absolutely. The ASA Difficult Airway Algorithm includes the possible use of a videoscope, and states,
“Consider the relative merits and feasibility of basic management choices:  (consider) video-assisted laryngoscopy as an initial approach to intubation.” An anesthesia provider who initiates general anesthesia and intubation without an immediately available videolaryngoscope is in danger of not being able to follow the algorithm. The hospital I work in is stocked with either the GlideScope and the C-MAC both readily available for difficult intubations. The availability of a videolaryngoscope for either a first attempt or for backup attempts to intubate a difficult airway patient is vital.

Difficult airway cases can lead to malpractice claims. A 2009 study published in Anesthesiology showed that 2.3% of 2,211 anesthesia-related deaths in the United States from 1999-2005 were attributable to difficult intubation and failed intubation.  A 2019 study from the Anesthesia Closed Claims Project database showed that the 102 difficult intubation closed malpractice claims from 2000 to 2012 included sicker patients (n = 78 of 102), emergency procedures (n = 37 of 102), and non-perioperative locations (n = 23 of 102).  Preoperative predictors of difficult tracheal intubation were present in only 76% of the patients. Inappropriate airway management occurred in 71 patients. A “can’t intubate, can’t oxygenate” emergency occurred in 80 of the 102 claims, with a delayed surgical airway occurring in 39% of those cases. The authors wrote, “outcomes remained poor in recent malpractice claims related to difficult tracheal intubation. Inadequate airway planning and judgment errors were contributors to patient harm.”

In conclusion: Difficult intubations are a major anesthesia problem, because of: 1) the difficulty in identifying difficult intubation patients prospectively, 2) the medical comorbidities that occur with difficult airway patients, 3) the medical complications that can occur if difficult airways are mismanaged, 4) the dollar cost of increased healthcare utilization as reported in the Moucharite study, and 5) the potential medical-legal liability risk with each difficult intubation.

SuperMorbidly Obese Patient with a Difficult Airway

 

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The most popular posts for laypeople on The Anesthesia Consultant include: How Long Will It Take To Wake Up From General Anesthesia? Why Did Take Me So Long To Wake From General Anesthesia? Will I Have a Breathing Tube During Anesthesia? What Are the Common Anesthesia Medications? How Safe is Anesthesia in the 21st Century? Will I Be Nauseated After General Anesthesia? What Are the Anesthesia Risks For Children?

The most popular posts for anesthesia professionals on The Anesthesia Consultant  include: 10 Trends for the Future of Anesthesia Should You Cancel Anesthesia for a Potassium Level of 3.6? 12 Important Things to Know as You Near the End of Your Anesthesia Training Should You Cancel Surgery For a Blood Pressure = 170/99? Advice For Passing the Anesthesia Oral Board Exams What Personal Characteristics are Necessary to Become a Successful Anesthesiologist?

 

READ ABOUT RICK NOVAK’S FICTION WRITING AT RICK NOVAK.COM

THE NEW 2022 ASA DIFFICULT AIRWAY ALGORITHM

Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group
Richard Novak, MD is a Stanford physician board certified in anesthesiology and internal medicine.Dr. Novak is an Adjunct Clinical Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Stanford University, the Medical Director at Waverley Surgery Center in Palo Alto, California, and a member of the Associated Anesthesiologists Medical Group in Palo Alto, California.
emailrjnov@yahoo.com
THE ANESTHESIA CONSULTANT

The American Society of Anesthesiologists (ASA) just published a 2022 update on their ASA Difficult Airway Algorithm Guidelines. The 2022 document is a revision of the 2013 publication “Practice guidelines for management of the difficult airway: A report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway.” The 2022 ASA Difficult Airway Algorithm Guidelines are 51 pages in total.

The most important changes are identified by examining the 2013 and the 2022 algorithms side by side. Let’s look at the 2013 flow chart algorithm and compare it to the 2022 flow chart algorithm below:

THE 2013 ASA DIFFICULT AIRWAY ALGORITHM

THE 2022 ASA DIFFICULT AIRWAY ALGORITHM

Note these major changes from 2013 to 2022:

  1. The top third of the 2022 algorithm lists factors which direct the anesthesiologist to perform awake intubation. The reason for this change is undoubtably the wisdom of utilizing awake intubation when a significant risk of a difficulty airway exists. There are minimal airway risks when a patient is awake, and the benefit of placing the endotracheal tube in a difficult airway patient while the patient is awake is immense. When we give mock oral board examinations to anesthesia residents at Stanford, and we describe to the examinee that the patient has a difficult airway, the answer of “I’d do an awake intubation” is hard to criticize and almost never leads to a catastrophe. In contrast, inducing general anesthesia prior to intubation in these patients can lead to a “Can’t intubate-can’t oxygenate” emergency, which can lead to a cardiac arrest and possible anoxic brain damage.
  2. The text highlighted in red in the 2022 document is both new and vital. The first of these is “OPTIMIZE OXYGENATION THROUGHOUT,” under the pathway INTUBATION ATTEMPT WITH PATIENT AWAKE, with the footnote 2Low- or high-flow nasal cannula, head elevated position throughout procedure. Noninvasive ventilation during preoxygenation. The message is to keep oxygen flowing via nasal cannula throughout airway management attempts to minimize hypoxia, and to keep the head elevated to maximize the functional residual capacity (FRC), which is the reservoir of oxygen in the patient’s lungs.
  3. LIMIT ATTEMPTS, Consider calling for help” is new and printed within a red box in the INTUBATION ATTEMPT AFTER GENERAL ANESTHESIA –> FAILED pathway. This is an effort to prevent repetitive unsuccessful intubation attempts from soaking up precious time, during which the brain is poorly oxygenated.
  4. LIMIT ATTEMPTS AND CONSIDER AWAKENING THE PATIENT” is new and printed in red in the NON-EMERGENCY PATHWAY under the “Ventilation adequate/intubation unsuccessful” pathway. This is again an effort prevent repetitive unsuccessful intubation attempts from soaking up precious time, during which the brain is poorly oxygenated.
  5. LIMIT ATTEMPTS AND BE AWARE OF THE PASSAGE OF TIME, CALL FOR HELP/FOR INVASIVE ACCESS” is new and printed in red in the EMERGENCY PATHWAY under the MASK VENTILATION NOT ADEQUATE, SUPRAGLOTTIC AIRWAY NOT ADEQUATE pathway. This is again an effort to prevent repetitive unsuccessful intubation attempts from soaking up precious time, during which the brain is poorly oxygenated.

These changes, printed or boxed in red, emphasize that the pace of difficult airway decisions is important. The duration of elapsed time is vital. When an anesthesia provider cannot intubate the patient and then cannot ventilate the patient, the oxygen level in the blood can plummet. There is a significant danger of anoxic brain damage within minutes. I’ve previously reviewed this topic in a 2019 Anesthesia Grand Rounds Lecture at Stanford, summarized in my article “Five Minutes to Avoid Anoxic Brain Damage.” The U.S. Library of Medicine website states that “Brain cells are very sensitive to a lack of oxygen. Some brain cells start dying less than 5 minutes after their oxygen supply disappears. As a result, brain hypoxia can rapidly cause severe brain damage or death,” and “Time is very important when an unconscious person is not breathing. Permanent brain damage begins after only 4 minutes without oxygen, and death can occur as soon as 4 to 6 minutes later.”

The sentence “Be aware of the passage of time, the number of attempts, and oxygen saturation” appears more than once in the 2022 Difficult Airway Algorithm Guidelines article, and is a key point for all anesthesia providers who encounter a difficulty airway emergency.

In my roles as an anesthesia quality assurance reviewer or a medical-legal expert consultant, I’ve seen this issue arise multiple times. Even though anesthesia providers believe they are following the Difficult Algorithm accurately, they are doing things too slowly, and they waste too much time. Once it’s clear that a “Cannot intubate-cannot oxygenate” scenario is occurring, the time clock is running, and the anesthesia provider must not only do the correct thing but he or she must do the correct thing without undue delay. The necessary procedure may be as invasive as a cricothyroidotomy/front of the neck access via the scalpel-bougie-endotracheal tube approach.  

The five points listed above are the major changes in the algorithm. In addition, the new 2022 article includes a Pediatric Difficult Airway Algorithm and an approach to Extubation of the Trachea in a Difficult Airway Patient. Other important quotes from the 2022 article include (bold emphasis added):

  1. “The consultants and members of participating organizations strongly agree with recommendations to perform awake intubation, when appropriate, if the patient is suspected to be a difficult intubation and difficult ventilation (face mask/supraglottic airway) is anticipated.”
  2. “Meta-analyses of randomized controlled trials comparing video-assisted laryngoscopy with direct laryngoscopy in patients with predicted difficult airways reported improved laryngeal views, a higher frequency of successful intubations, a higher frequency of first attempt intubations, and fewer intubation maneuvers with video-assisted laryngoscopy.”
  3. The footnote (7) for alternative difficult intubation approaches states: 7Alternative difficult intubation approaches include but are not limited to video-assisted laryngoscopy, alternative laryngoscope blades, combined techniques, intubating supraglottic airway (with or without flexible bronchoscopic guidance), flexible bronchoscopy, introducer, and lighted stylet or lightwand. 
  4. “A randomized controlled trial comparing a videolaryngoscope combined with a flexible bronchoscope reported a greater first attempt success rate with the combination technique than with a videolaryngoscope alone.”
  5. When appropriate, refer to an algorithm and/or cognitive aid.” 

AUTHOR’S NOTE: I’d suggest that the Stanford Emergency Manual of cognitive aid algorithms for anesthesia and ACLS emergencies be onsite at all anesthetizing locations. 

I’d also recommend that the 2022 ASA Difficult Airway guideline algorithm be onsite at all anesthetizing locations.

Every anesthesia professional will encounter patients with difficult airways—this is one of the most important and most feared situations in our specialty. Commit the 2022 ASA Difficult Airway Algorithm to memory. Use awake intubation when you’re concerned about the potential of a “Cannot intubate-cannot oxygenate” scenario. And if you’re in the middle of a difficult airway emergency, call for help and be aware of the passage of time, the number of attempts, and the oxygen saturation. Don’t let an excessive number of minutes elapse without regaining oxygenation of your patient.

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The most popular posts for laypeople on The Anesthesia Consultant include:
How Long Will It Take To Wake Up From General Anesthesia?
Why Did Take Me So Long To Wake From General Anesthesia?
Will I Have a Breathing Tube During Anesthesia?
What Are the Common Anesthesia Medications?
How Safe is Anesthesia in the 21st Century?
Will I Be Nauseated After General Anesthesia?
What Are the Anesthesia Risks For Children?

The most popular posts for anesthesia professionals on The Anesthesia Consultant  include:
10 Trends for the Future of Anesthesia
Should You Cancel Anesthesia for a Potassium Level of 3.6?
12 Important Things to Know as You Near the End of Your Anesthesia Training
Should You Cancel Surgery For a Blood Pressure = 170/99?
Advice For Passing the Anesthesia Oral Board Exams
What Personal Characteristics are Necessary to Become a Successful Anesthesiologist?

READ ABOUT RICK NOVAK’S FICTION WRITING AT RICK NOVAK.COM.

FRONT OF NECK ACCESS

Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group
Richard Novak, MD is a Stanford physician board certified in anesthesiology and internal medicine.Dr. Novak is an Adjunct Clinical Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Stanford University, the Medical Director at Waverley Surgery Center in Palo Alto, California, and a member of the Associated Anesthesiologists Medical Group in Palo Alto, California.
emailrjnov@yahoo.com
THE ANESTHESIA CONSULTANT

Can you perform an emergency surgical cricothyroidotomy? In the dreaded Can’t Intubate, Can’t Oxygenate (CICO) scenario, if your patient has no airway, you must immediately establish a front of neck access (FONA) to save your patient’s life.

SCALPEL, BOUGIE, TUBE APPROACH TO CRICOTHYROIDOTOMY

SCALPEL, BOUGIE, TUBE APPROACH TO CRICOTHYROIDOTOMY

This week I attended an outstanding Stanford Anesthesia Grand Rounds delivered by Drs. Jeremy Collins, Susan Galgay, and Tom Bradley. The lecture reviewed the literature regarding CICO events, and concluded that performing a surgical airway through the cricoid membrane is an essential skill for anesthesiologists.

Most anesthesia professionals have never cut into a patient’s neck, but we must own this skill if the necessity arises. I’ve done thousands of cases over 34 years. I have never performed a surgical cricothyroidotomy, but I may need to do one tomorrow. It’s essential expertise for myself and for every anesthesiologist.

As I’ve reviewed in previous columns, a lack of oxygen to the brain for five minutes can cause anoxic brain damage—a disaster all anesthesiology professionals must avoid. The specter that someday we will induce and paralyze a morbidly obese patient, and then be unable to intubate or oxygenate that patient, is in the back of the mind of every anesthesia professional. If and when this happens, we must be able to act without hesitation to oxygenate the patient via FONA.

CICO events are rare, but they do occur with a published incidence of 1 in 50,000 anesthetics, per the fourth national audit project in the United Kingdom (NAP4).  Approaches to FONA include either cannula techniques or surgical techniques, with significant differences.

Cannula Techniques:

These involve inserting a large bore IV catheter through the cricothyroid membrane. Because the lumen of a 14-gauge IV catheter is small, ventilation requires a high- pressure jet oxygen delivery system. In Duggan’s publication from 2016, the failure rate with cannula techniques was 42% in CICO emergencies. In addition, barotrauma occurred in 32% of CICO emergency procedures. Fifty-one percent of CICO emergency events managed with a FONA cannula had a complication. Several reports described trans-tracheal jet ventilation-related subcutaneous emphysema hampering subsequent attempts at surgical airway or tracheal intubation. Failure can also occur because of kinking, malposition, or displacement of the needle/cannula. The Stanford Anesthesia Grand Rounds concluded that these failure rates and complications with cannula FONA techniques were prohibitively high.

Surgical Techniques:

The cricothyroid membrane is divided by a surgical incision made with a wide scalpel (#10 scalpel). With the scalpel, bougie, tube (SBT) technique, a bougie is inserted into the trachea through the incision. A lubricated 6.0 mm cuffed endotracheal tube is advanced over the bougie into the trachea, and the bougie is removed.

There are contrasting difficult airway algorithms algorithms for different English-speaking countries around the globe. See this link for the algorithms from the United States, Australia, Canada, and United Kingdom. Each has unique recommendations for CICO emergencies.

The American Society of Anesthesiologists Difficult Airway Algorithm outlines an approach to airway management, but at the bottom right of the chart, the plan for the CICO situation is “Emergency Invasive Airway Access.” A footnote reads “invasive airway access includes surgical or percutaneous airway, jet ventilation, and retrograde intubation.” The algorithm gives no definitive choice of which technique to use. This is a shortcoming of the American algorithm. There are invasive airway options, and in an emergency there can be no wavering or doubts regarding what to do. Per the data above, percutaneous airway and jet ventilation carry high failure and complication rates. Per discussion at the Stanford Anesthesia Grand Rounds, retrograde intubation is too slow, too difficult, and should be eliminated from the recipe for emergency lifesaving treatment.

The Australian algorithm uses the Vortex approach to managing an unexpected difficult airway.

the vortex approach

THE VORTEX APPROACH

Three options (face mask, endotracheal intubation, and laryngeal mask airway) are all attempted, in any order, to establish a patent airway. If all three methods fail to establish a patent airway, this (not the occurrence of oxygen desaturation) is the trigger to establish an emergency surgical airway (ESA). ESA techniques include either cannula or scalpel cricothyroidotomy to provide a patent airway as rapidly as possible. Note that the Australian Vortex approach endorses either cannula or scalpel cricothyroidotomy, and recommends that anesthesiologists be familiar with both FONA techniques.

The conclusions reached in the Stanford Grand Rounds most closely adhered to the British algorithm, which advocates the SBT (scalpel, bougie, endotracheal tube) method to securing a surgical airway. The SBT method has been specifically endorsed in the United Kingdom Difficult Airway Society algorithm. What follows is the text from the United Kingdom Difficult Airway Society guideline for a Can’t Intubate, Can’t Oxygenate event:

 

The United Kingdom Difficult Airway Society guideline for Failed intubation, failed oxygenation in the paralyzed, anaesthetised patient:

Fig5-Failed-intubation-failed-oxygenation-in-the-paralysed-anaesthetized-patient

Author’s addendum: Many or most patients who suffer CICO events will be obese and have thick or short necks. The cricothyroid membrane may not be easily palpable. Per the text above, the United Kingdom Difficult Airway Society guidelines recommend you make an 8-10 cm vertical skin incision, caudad to cephalad, over the cricothyroid area. This type of surgical maneuver is not a routine part of anesthetic practice, and it will require both skill and courage to commit to the incision. The guidelines next ask you to use blunt dissection with the fingers of both hands to separate tissues until you can identify the larynx and palpate the cricothyroid membrane. Once the cricothyroid membrane is identified, the scalpel incision is made through the cricothyroid membrane. This technique will no doubt create bleeding in the anterior neck, and will not be easy to perform. Enlisting the surgeon’s help during the procedure is advisable. Remember that controlling bleeding is not the primary issue—the primary goal is to locate the cricothroid membrane deep to the adipose of the anterior neck.

When I was a resident I was trained to give cricothyroid injections of lidocaine or cocaine to anesthetize the lumen of the trachea prior to awake fiberoptic intubations. The anatomy of the cricothyroid membrane in most patients is easily palpable, and it can be penetrated with minimal effort or bleeding. In a morbidly obese patient, this approach will be more difficult.

 

How to train anesthesiologists to perform SBT cricothyroidotomy:

This was the subject of discussion at the end of Grand Rounds. Because of the extreme rarity of CICO events, skills will be absent, lost, or dormant for many practitioners. Practice on simulators or plastic models at 6 months intervals was recommended. Dr. Bradley explained that in one approach in Britain, a two-person team traveled from operating room to operating room to teach the SBT method. One member of the teaching team relieved the anesthesiologist from the operating room, and the second member then took the anesthesiologist a room to enjoy a pot of tea and to learn from a plastic training model of the cricothyroid membrane. The final proposals for education and re-education to retain skills at Stanford and throughout the world are challenges for the future. Note that surgeons have almost no education at cricothyroid approaches. Head and neck surgeons are trained in tracheostomy, a different procedure that likely will take too much time to perform when compared to a cricothyroidotomy. Training of surgical colleagues also needs to be addressed in the future.

 

What You Should Do Now:

  1. Familiarize yourself with the anatomy of the cricothyroid membrane on each of your patients.
  2. Have an SBT kit containing a #10 scalpel, a bougie, and a #6 cuffed endotracheal tube included with each difficult airway cart at each facility you anesthetize at.
  3. I now carry an SBT kit in my briefcase which I take with me every day at work. In the current model of private practice in California, where we work at multiple different freestanding surgery centers and surgeon offices, this is a reliable means to assure that I have FONA equipment with me wherever I anesthetize patients.
  4. Be prepared. Review and rehearse the anatomy and skills necessary to perform front of neck surgical cricothyroidotomy in seconds.
  5. Work to avoid CICO events. Evaluate each airway prior to surgery. If a significant concern exists regarding a difficult intubation, a difficult mask ventilation, or a difficult FONA, use your judgment and perform an awake intubation. Securing an airway prior to anesthesia induction is a reliable way to avoid CICO disasters.

 

Two important take-home messages from this column are:

  1. Learn the specific the SBT recipe for front of neck access.
  2. Don’t hesitate and waste seconds—it will take courage to grab that scalpel, but that’s your job and your duty to your patient.

 

For further discussion and advice on airway emergencies, see my columns on Avoiding Airway Lawsuits, Airway Disasters, and The Most Important Technical Skill For an Anesthesiologist.

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The most popular posts for laypeople on The Anesthesia Consultant include:

How Long Will It Take To Wake Up From General Anesthesia?

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Will I Be Nauseated After General Anesthesia?

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Advice For Passing the Anesthesia Oral Board Exams

What Personal Characteristics are Necessary to Become a Successful Anesthesiologist?

 

 

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THE MOST IMPORTANT TECHNICAL SKILL FOR AN ANESTHESIOLOGIST?

Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group
Richard Novak, MD is a Stanford physician board certified in anesthesiology and internal medicine.Dr. Novak is an Adjunct Clinical Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Stanford University, the Medical Director at Waverley Surgery Center in Palo Alto, California, and a member of the Associated Anesthesiologists Medical Group in Palo Alto, California.
emailrjnov@yahoo.com
THE ANESTHESIA CONSULTANT

What’s the most critical technical skill for an anesthesiologist? I ask this question when I’m teaching anesthesia residents and medical students. Their most frequent answer is . . . the ability to place an endotracheal tube. This is the wrong answer. The most critical technical skill for an anesthesiologist is . . . facemask ventilation. Why?

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All acute medical care follows the sequence of A-B-C, or Airway, Breathing, Circulation. Control of the airway is the most important clinical priority in anesthesia care. Placement of an endotracheal tube to establish an airway is an essential skill, but at times it’s difficult or near impossible to intubate the trachea on the first attempt.

The American Society of Anesthesiologists  Difficult Airway Algorithm addresses this issue. The Algorithm recommends, “Actively pursue opportunities to deliver supplemental oxygen throughout the process of difficult airway management. Opportunities for supplemental oxygen administration include (but are not limited to) oxygen delivery by nasal cannulae, facemask, or LMA, insufflation; and oxygen delivery by facemask, blow-by, or nasal cannulae after extubation of the trachea.”

In emergency situations, maintenance of oxygen delivery by facemask can be critical.

The INTUBATION AFTER INDUCTION OF GENERAL ANESTHESIA section of the Difficult Airway Algorithm is bifurcated into two pathways. The left side is labeled FACE MASK VENTILATION ADEQUATE. The right side is labeled FACE MASK VENTILATION NOT ADEQUATE.

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The left side FACE MASK VENTILATION ADEQUATE leads to a NONEMERGENCY PATHWAY algorithm. The right side FACE MASK VENTILATION NOT ADEQUATE begins with CONSIDER/ATTEMPT SGA (Supraglottic Airway), but if SGA placement is unsuccessful, the right side FACE MASK VENTILATION NOT ADEQUATE pathway leads directly to an EMERGENCY PATHWAY algorithm subtitled “Ventilation not adequate, intubation unsuccessful.”

“Ventilation not adequate, intubation unsuccessful” is a circumstance every anesthesiologist dreads, and every anesthesiologist hopes to avoid. Failure to keep a patient oxygenated can lead to hypoxia and brain death in as short a time as three minutes.

One way to spend less time on the right side of the ASA Difficult Airway Algorithm is to be expert and proficient in facemask ventilation.

In my practice, I’d estimate 1 – 2 patients out of every 100 patients, or 7 – 10 patients per year, present an unexpected difficult intubation. In my preoperative assessment I believe their intubation will be routine or only moderately difficult. After I induce general anesthesia and paralyze the patient, I find their larynx is anterior and difficult to visualize by direct laryngoscopy. In these patients in which my initial attempt(s) are unsuccessful, repeat laryngoscopies are required, and facemask ventilation between laryngoscopies to maintain oxygenation and ventilation is critical.

A second intubation attempt may involve a change in head and neck positioning, oropharangeal suctioning, or a different laryngoscope. If these modifications are unsuccessful, video laryngoscopy is indicated. A recent study in Anesthesiology showed video laryngoscopy to be the most successful technique to achieve successful tracheal intubation after failed direct laryngoscopy, with a 92% rescue rate. Video laryngoscopy is known to be associated with improved visualization of the larynx , although placement of the tube into the trachea may still require repeated attempts, requiring alteration in curve of the stylet or repositioning of the laryngoscope.

Some might argue that the use of video laryngoscopy for the first attempt at endotracheal intubation will eliminate this problem. But as described above, for difficult airways or obese patients, even video laryngoscopy can require repeated attempts because of difficulty advancing the tube into the trachea. No data exists to support that initial video laryngoscopy is safer or more effective than direct laryngoscopy when used by anesthesiologists in operating rooms.

Airway and Breathing must be maintained by facemask ventilation until an endotracheal airway or supraglottic airway is established. The manual skill of maintaining a seal between the mask and the patient’s face requires strength. The four fingers hold the caudal aspect of the mask firmly against the chin, and also serve to extend the patient’s neck. The thumb presses down on the cephalad aspect of the mask against the bridge of the nose. The right hand squeezes the ventilation bag on the anesthesia machine.

An anesthesiologist with an injured or impaired left hand is unable to safely ventilate a patient via facemask, especially an overweight patient or a patient with a beard or abnormal facial anatomy. Because of this, an anesthesiologist with an injured or impaired left hand should not be administering general anesthesia. Anesthesiologists would be wise to avoid hand or wrist injuries which could make them unemployable. Anesthesiologists would be wise to avoid falling on their outstretched hands. The pastimes of bicycle riding, skateboarding, rollerblading, climbing ladders, and rock climbing are all fraught with hand-injury danger. Should anesthesiologists avoid these activities? At the very least, anesthesiologists need to be overly careful with these activities.

Operating room practice requires anesthesiologists to perform multiple additional technical procedures, including the placement of IVs, arterial lines, central venous catheters, spinal blocks, epidural blocks, and ultrasound-guided regional nerve blocks. Each of these skills is important, but none of them are as critical as the ability to keep a patient oxygenated, first with a facemask, and second by placing an airway tube.

In a previous column, I described a case in which an anesthesiologist lost the airway on a pregnant woman following induction of general anesthesia for Cesarean section. The acute situation led to the anesthesiologist’s unrelenting focus on repeat laryngoscopies, at the expense of the facemask ventilation needed to return the oxygen saturation to a level greater than 90%. Failure to keep the patient oxygenated through repeated intubation attempts can lead to hypoxia and brain death.

The full list of the intellectual, technical, and personal qualities necessary to succeed in the profession of anesthesiology are summarized in my column On Becoming an Anesthesiologist – What Personal Characteristics are Essential.

 

The most popular posts for laypeople on The Anesthesia Consultant include:

How Long Will It Take To Wake Up From General Anesthesia?

Why Did Take Me So Long To Wake From General Anesthesia?

Will I Have a Breathing Tube During Anesthesia?

What Are the Common Anesthesia Medications?

How Safe is Anesthesia in the 21st Century?

Will I Be Nauseated After General Anesthesia?

What Are the Anesthesia Risks For Children?

 

The most popular posts for anesthesia professionals on The Anesthesia Consultant  include:

10 Trends for the Future of Anesthesia

Should You Cancel Anesthesia for a Potassium Level of 3.6?

12 Important Things to Know as You Near the End of Your Anesthesia Training

Should You Cancel Surgery For a Blood Pressure = 178/108?

Advice For Passing the Anesthesia Oral Board Exams

What Personal Characteristics are Necessary to Become a Successful Anesthesiologist?

 

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Published in September 2017:  The second edition of THE DOCTOR AND MR. DYLAN, Dr. Novak’s debut novel, a medical-legal mystery which blends the science and practice of anesthesiology with unforgettable characters, a page-turning plot, and the legacy of Nobel Prize winner Bob Dylan.

KIRKUS REVIEW

In this debut thriller, tragedies strike an anesthesiologist as he tries to start a new life with his son.

Dr. Nico Antone, an anesthesiologist at Stanford University, is married to Alexandra, a high-powered real estate agent obsessed with money. Their son, Johnny, an 11th-grader with immense potential, struggles to get the grades he’ll need to attend an Ivy League college. After a screaming match with Alexandra, Nico moves himself and Johnny from Palo Alto, California, to his frozen childhood home of Hibbing, Minnesota. The move should help Johnny improve his grades and thus seem more attractive to universities, but Nico loves the freedom from his wife, too. Hibbing also happens to be the hometown of music icon Bob Dylan. Joining the hospital staff, Nico runs afoul of a grouchy nurse anesthetist calling himself Bobby Dylan, who plays Dylan songs twice a week in a bar called Heaven’s Door. As Nico and Johnny settle in, their lives turn around; they even start dating the gorgeous mother/daughter pair of Lena and Echo Johnson. However, when Johnny accidentally impregnates Echo, the lives of the Hibbing transplants start to implode. In true page-turner fashion, first-time novelist Novak gets started by killing soulless Alexandra, which accelerates the downfall of his underdog protagonist now accused of murder. Dialogue is pitch-perfect, and the insults hurled between Nico and his wife are as hilarious as they are hurtful: “Are you my husband, Nico? Or my dependent?” The author’s medical expertise proves central to the plot, and there are a few grisly moments, as when “dark blood percolated” from a patient’s nostrils “like coffee grounds.” Bob Dylan details add quirkiness to what might otherwise be a chilly revenge tale; we’re told, for instance, that Dylan taught “every singer with a less-than-perfect voice…how to sneer and twist off syllables.” Courtroom scenes toward the end crackle with energy, though one scene involving a snowmobile ties up a certain plot thread too neatly. By the end, Nico has rolled with a great many punches.

Nuanced characterization and crafty details help this debut soar.

Click on the image below to reach the Amazon link to The Doctor and Mr. Dylan:

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LEARN MORE ABOUT RICK NOVAK’S FICTION WRITING AT RICK NOVAK.COM BY CLICKING ON THE PICTURE BELOW:

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AVOIDING AIRWAY DISASTERS IN ANESTHESIA

Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group
Richard Novak, MD is a Stanford physician board certified in anesthesiology and internal medicine.Dr. Novak is an Adjunct Clinical Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Stanford University, the Medical Director at Waverley Surgery Center in Palo Alto, California, and a member of the Associated Anesthesiologists Medical Group in Palo Alto, California.
emailrjnov@yahoo.com
THE ANESTHESIA CONSULTANT

Every anesthesia practitioner dreads airway disasters.  Anesthesiologists and nurse anesthetists are airway experts, but anesthesia professionals are often the only person in the operating room capable of keeping a patient alive if the patient’s airway is occluded or lost. Hypoxia from an airway disaster can lead to brain damage within minutes, so there is little time for human error.

A fundamental skill is the ability to assess a patient’s airway prior to anesthesia. One must assess whether the patient will pose: 1) difficult bag-mask ventilation, 2) difficult supraglottic/laryngeal mask airway placement, 3) difficult laryngoscopy, 4) difficult endotracheal intubation, or 5) difficult surgical airway.

Of critical importance is #1) above, that is, recognizing the patient who will present difficult mask ventilation. Conditions that make for difficult bag-mask ventilation are uncommon, and usually can be detected during physical examination. Despite the importance of expertise in endotracheal intubation, I teach residents and trainees that the most important airway skill is bag-mask ventilation. Every year I encounter several patients who present unanticipated difficult intubations. In each of these patients, I’m able to mask ventilate the patient to keep them oxygenated while I try various strategies and techniques to successfully place an endotracheal tube or a laryngeal mask airway.

Most anesthesia airway disasters aren’t merely difficult intubations, but scenarios that are classified as “can’t intubate, can’t ventilate.” In these “can’t intubate, can’t ventilate” situations, the anesthesiology professional has only minutes to restore oxygenation to the patient or else the risk of permanent brain damage is very real.

The American Society of Anesthesiologists Difficult Airway Algorithm is a guide for anesthesia practitioners regarding how proceed in airway management. The algorithm is detailed, complex, comprehensive, and defines the standard of care in any medical-legal battle concerning hypoxic brain damage due difficult airway clinical cases. The algorithm is so detailed, complex, and comprehensive that some would say it’s impossible to remember every step in the acute occurrence of an airway disaster.

A simplified approach has been touted.

Dr. C. Philip Larson, Professor Emeritus, Anesthesia and Neurosurgery, Stanford University, and Professor of Clinical Anesthesiology at UCLA, and previous Chairman of Anesthesiology at Stanford, was one of my teachers and mentors for both endotracheal intubation and fiberoptic intubation. In a Letter to the Editor of the Stanford Gas Pipeline in May, 2013, Dr. Larson wrote, “there is no scientific evidence that anesthesia is safer because of the ASA Difficult Airway Algorithm.  While an interesting educational document, I question the daily clinical value of this algorithm, even in its most recent form (Anesthesiology 2013; 118:251-70). The ASA Difficult Airway Algorithm was developed by committee and has all the problems that result when done that way.  It is complex, diffuse, multi-dimensional, and all-encompassing such that it is not an instrument that one can easily adopt and practice in the clinical setting.”

Dr. Larson recommends a system of Plans A-D, a system he published in Clinical Anesthesiology, editors Morgan GE, Mikhail MS, Murray MJ, Lange Medical publication, 4th edition, 2006, pp 104-5, and in Current Reviews in Clinical Anesthesiology (2009; 30:61-72), and also in the Appendix on airway management and intubation in the newest edition of Anesthesiologists Manual of Surgical Procedures by Richard Jaffe et al (Lippincott Williams and Wilkins, 5th Edition, May 2014). An outline of the system is as follows:

A.  Plan A is direct laryngoscopy an intubation using a Miller or MacIntosh blade.

B.  If Plan A is unsuccessful, Plan B includes use of video laryngoscopy with a GlideScope or similar device.

C.  If Plan B is unsuccessful, Plan C is placement of an LMA with intubation through that LMA using a fiberoptic bronchoscope.

D.  “If Plans A-C fail,” Larson wrote in his Letter to the Editor of the Stanford Gas Pipeline in May, 2013, “one needs Plan D.  The first and perhaps the most prudent option is to cancel the proposed operation, terminate the anesthetic, and wake the patient up. The operation would be rescheduled for another day, and at that time an awake fiberoptic intubation technique would be used.  Alternatively, if the operation cannot be postponed, then the surgeon should be informed that a surgical airway (i.e.: tracheostomy) must be performed before the planned operation can commence.  To date, utilization of Plan D because of failure of Plans A-C has not occurred.”

Dr. Larson wrote that the airway skills in Plan A – C should be practiced regularly on patients with normal airways. I agree with Dr. Larson that in managing difficult airways, a practitioner needs a short list of procedural skills that he or she is expert at rather that a large array of procedures that they rarely use (such as the alternative intubation techniques using light wands or blind nasal techniques, or invasive airway procedures such as retrograde wires passed through the cricothyroid membrane or transtracheal jet ventilation through a catheter). It’s wise for anesthesiologists to regularly hone their techniques of video laryngoscopy (Plan B) and fiberoptic intubation via an LMA (Plan C) on patients with normal airways, to remain expert with these skills.

Regarding Plan B, an important advance is the availability of portable, disposable video laryngoscopes such as the Airtraq, a guided video intubation device. In my career I sometimes work in solo operating room suites distant from hospitals. In these settings, the operating room is usually not be stocked with an expensive video scope such as the GlideScope, the C-MAC, or the McGrath 5. I carry an Airtraq in my briefcase, and if the need for Plan B arises I am prepared to utilize video laryngoscopy at any anesthetizing location. I suggest the practice of carrying an Airtraq to any anesthesiologist who gives general anesthetics in remote locations.

Regarding emergency surgical rescue airway management, Dr. Larson recently published a Letter to the Editor in the American Society of Anesthesiologists Newsletter, February 2014, entitled, Ditch the Needle – Teach the Knife. In this letter, Dr. Larson wrote:

“in life-threatening airway obstruction, … an emergency cricothyrotomy is much quicker, easier, safer and more effective than any needle-based technique. I can state with confidence that there is no place in emergency airway management for needle-based attempts to establish ventilation. It should be deleted from the ASA Difficult Airway Algorithm. I have participated in seven cricothyrotomies in emergency airway situations, and all of the patients left the hospital without any neurological injury or complications from the cricothyrotomy. The risk-benefit ratio is markedly in favor the knife technique…. With a knife, or scissors, one cuts quickly either vertically or horizontally below the thyroid cartilage and there is the cricothyroid membrane or tracheal rings. The knife is inserted into the trachea and turned 90 degrees, and an airway is established. At that point, a small tube of any type can be inserted next to the knife. The knife technique is much safer because there is virtually nothing that one can harm by making an incision within two inches or less in the midline of the neck, and it can be performed in less than 30 seconds. In contrast, the needle is fraught with complications, including identifying the trachea, making certain that the needle is entirely in the trachea and does not move ( to avoid subcutaneous emphysema when an oxygen source is established), establishing a pressurized oxygen delivery system (which will take more than five minutes even in the most experienced circumstances), and avoiding causing a tension pneumothorax… I know of multiple cases of acute airway obstruction where the needle technique was attempted, and in all cases the patients died. I know of no such cases when a cricothyrotomy was used as the primary treatment of acute airway obstruction.”

A final note on the awake intubation of patients with a difficult airway: In hindsight in any difficult airway case, one often wishes they had secured an endotracheal tube prior to the induction of general anesthesia. The difficult problem is deciding prior to a case which patient has such a difficult airway that the induction of general anesthesia should be delayed until after intubation. In anesthesia oral board examinations it may be wise to say you would perform an awake intubation on a difficult airway patient rather than risk the “can’t intubate, can’t ventilate” scenario the examiner is probably poised to skewer you with. In medical malpractice lawsuits, plaintiff expert witnesses in anesthesia airway disaster cases often testify that a brain-dead patient’s life would have been saved if only the anesthesiologist had performed awake intubation rather than inducing general anesthesia first and then losing the airway. The key question is: how does one decide which patient needs an awake intubation? As an anesthesia practitioner, if you performed awake intubations on one out of 50 cases because you were worried about a difficult airway, you would delay operating rooms and surgeons multiple times per year because of your caution. You will not be popular if you do this. In my clinical practice and in the practice of the excellent Stanford anesthesiologists I work with, the prevalence of awake intubation is very low. I estimate most anesthesiologists perform between zero and two awake intubations per year. The most common indications include patients with severe ankylosing spondylitis of the cervical spine, congenital airway anomalies, and severe morbid obesity. Dr. Larson wrote in his Letter to the Editor of the Stanford Gas Pipeline in May, 2013, “I do anesthesia for most of the patients with complex head and neck tumors, and I find fewer and fewer indications for awake fiberoptic intubation. As long as the lungs can be ventilated by bag-mask or LMA, which is true for almost all sedated patients, Plan C is easier, quicker and safer than awake fiberoptic intubation both for the patient and the anesthesia provider.  In experienced hands, Plan C can be completed in less than 5 minutes, and one can become proficient by practicing in normal patients. I have done hundreds of Plan C’s, many under difficult circumstances, without a single failure or complication.  Obviously, no technique will encompass every conceivable airway problem, but mastering Plans A-D and awake oral and nasal fiberoptic intubation will meet the needs of anesthesia providers in almost all circumstances.”

May you never experience the  emotional trauma of an airway disaster. Become an expert in bag-mask ventilation, always have access to a video laryngoscope or an Airtraq, and consider  Dr. Larson’s  Plan A-D system, described in detail in the Appendix on airway management and intubation in the newest edition of Anesthesiologists Manual of Surgical Procedures by Richard Jaffe et al (Lippincott Williams and Wilkins, 5th Edition, May 2014).

 

The most popular posts for laypeople on The Anesthesia Consultant include:

How Long Will It Take To Wake Up From General Anesthesia?

Why Did Take Me So Long To Wake From General Anesthesia?

Will I Have a Breathing Tube During Anesthesia?

What Are the Common Anesthesia Medications?

How Safe is Anesthesia in the 21st Century?

Will I Be Nauseated After General Anesthesia?

What Are the Anesthesia Risks For Children?

 

The most popular posts for anesthesia professionals on The Anesthesia Consultant  include:

10 Trends for the Future of Anesthesia

Should You Cancel Anesthesia for a Potassium Level of 3.6?

12 Important Things to Know as You Near the End of Your Anesthesia Training

Should You Cancel Surgery For a Blood Pressure = 178/108?

Advice For Passing the Anesthesia Oral Board Exams

What Personal Characteristics are Necessary to Become a Successful Anesthesiologist?

 

 

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Published in September 2017:  The second edition of THE DOCTOR AND MR. DYLAN, Dr. Novak’s debut novel, a medical-legal mystery which blends the science and practice of anesthesiology with unforgettable characters, a page-turning plot, and the legacy of Nobel Prize winner Bob Dylan.

KIRKUS REVIEW

In this debut thriller, tragedies strike an anesthesiologist as he tries to start a new life with his son.

Dr. Nico Antone, an anesthesiologist at Stanford University, is married to Alexandra, a high-powered real estate agent obsessed with money. Their son, Johnny, an 11th-grader with immense potential, struggles to get the grades he’ll need to attend an Ivy League college. After a screaming match with Alexandra, Nico moves himself and Johnny from Palo Alto, California, to his frozen childhood home of Hibbing, Minnesota. The move should help Johnny improve his grades and thus seem more attractive to universities, but Nico loves the freedom from his wife, too. Hibbing also happens to be the hometown of music icon Bob Dylan. Joining the hospital staff, Nico runs afoul of a grouchy nurse anesthetist calling himself Bobby Dylan, who plays Dylan songs twice a week in a bar called Heaven’s Door. As Nico and Johnny settle in, their lives turn around; they even start dating the gorgeous mother/daughter pair of Lena and Echo Johnson. However, when Johnny accidentally impregnates Echo, the lives of the Hibbing transplants start to implode. In true page-turner fashion, first-time novelist Novak gets started by killing soulless Alexandra, which accelerates the downfall of his underdog protagonist now accused of murder. Dialogue is pitch-perfect, and the insults hurled between Nico and his wife are as hilarious as they are hurtful: “Are you my husband, Nico? Or my dependent?” The author’s medical expertise proves central to the plot, and there are a few grisly moments, as when “dark blood percolated” from a patient’s nostrils “like coffee grounds.” Bob Dylan details add quirkiness to what might otherwise be a chilly revenge tale; we’re told, for instance, that Dylan taught “every singer with a less-than-perfect voice…how to sneer and twist off syllables.” Courtroom scenes toward the end crackle with energy, though one scene involving a snowmobile ties up a certain plot thread too neatly. By the end, Nico has rolled with a great many punches.

Nuanced characterization and crafty details help this debut soar.

Click on the image below to reach the Amazon link to The Doctor and Mr. Dylan:

41wlRoWITkL

Learn more about Rick Novak’s fiction writing at ricknovak.com by clicking on the picture below:  

DSC04882_edited