The practice of anesthesia requires development of good decision making processes, in addition to remembering knowledge and learning skills. This article explores the decision process used for a case of securing the airway in a young child with a large airway abscess.
The decision-making and planning principals described here are discussed in more depth in my two Anesthesiology News Airway Management Review Articles, found here:
- 10 Common Pediatric Airway Problems and Their Solution
- Always Prepare For Failure: 10 Rules For Approaching Difficult Intubation
A 5-year-old, 15-kg girl, who had been sick with a severe sore throat and a fever for 3 days, was found to large retropharyngeal abscess. The interventional radiologist wanted to drain the abscess under CT guidance.
I met my patient as she was brought into radiology sitting on her Mother’s lap in a wheelchair. She had mild stridor and preferred to sit rather than lie flat. Her voice was slightly hoarse as she complained of a bad sore throat. Her breathing pattern appeared relaxed and comfortable, though she seemed anxious and suspicious of all the activity. The emergency room staff had already placed a 22g IV in the girl’s hand. She had had one dose of racemic epinephrine.
The right side of her face and the space under under her right chin was swollen and mildly erythematous. She could open her mouth to commands but said it hurt to open it wide. Her trachea appeared slightly deviated to the left and the base of her tongue on the right appeared slightly elevated. Her lungs were clear.
Pulse 120. BP 90/50. SPO2 97%. Temperature 101F (XXC). She had been mostly NPO for 16 hrs because she had refused to swallow liquids or food at home.
Perform Initial Assessment
What Are The Risks For This Child?
When faced with a difficult airway, I always ask myself some questions (1):
- Can I Ventilate?
- Large abscess causing swelling and stridor
- potential loss of the airway due to obstruction after induction or muscle relaxation
- Large abscess causing swelling and stridor
- Can I intubate?
- Large abscess deviating trachea with swelling above the cords
- May obscure view
- Need for smaller than normal endotracheal tube
- Increased risk of laryngospasm due to airway irritability
- Large abscess deviating trachea with swelling above the cords
- Are There Other Risk Factors?
- Age 5 years
- Limited cooperation: rules out awake intubation
- Children are at higher risk of hypoxia, cardiac arrest, and brain death due to airway problems (XX)
- higher metabolic rate, pediatric airway anatomy predisposed to obstruction, immature nervous system, immature cardiovascular and respiratory development
- Risk of aspiration of pus if abscess is ruptured during attempt
- Fever: increased risk hypoxia due to increased metabolic rate
- Probable dehydration: NPO 16 hrs. She has an IV but has not had a bolus.
- Inability to cooperate for awake techniques due to age
- Age 5 years
- Procedure to be performed in CT Scanner
- Location far from main anesthesia services
Form a Plan
Often there is more than one approach to a particular patient’s case. In one report, 9 internationally recognized airway management experts were asked to review a challenging airway case and make recommendations on how they would have proceeded. Eight different plans emerged, with several of the experts ruling out as too dangerous some of the proposed management steps that had been offered by their peers [2, 3]. However, each approach may offer different potential benefits and carry different risks. This difference doesn’t necessarily make any choice wrong, but it does mean you have to prepare before you begin to optimize its success. It also means having a Plan B, and possibly Plan C in place to prepare for failure in case things go awry.
Managing any airway compromised by an abscess is challenging. An abscess often distorts the airway, hindering ventilation or intubation. In addition, rupture of the abscess before intubation could potentially lead to fatal loss of the airway, aspiration, or pneumonia. Managing such an airway is especially problematic if the patient is a child, since lack of cooperation can limit options.
Who Is the Right Person For The Job?
An additional concern for this case is the age of the patient. I was a member of the pediatric core team with a lot of difficult airway experience. Had that not been the case, I might have needed to decide whether my hospital was the safest place to do this case and if I was the right provider to do this anesthetic. I say might because circumstances can dictate how much flexibility you have. If your patient cannot tolerate transport, or you are the only provider available, then you must proceed with caution.
In your career, you will encounter children with difficult airways, from either acute processes like epiglottitis or chronic conditions such as congenital anomalies. You must realistically assess whether you have the correct skills and, if not, what you can do to optimize the situation to maximize safety for the child.
Only an expert, or a provider working with an expert in airway management, should attempt intubation of a child with significant airway abnormalities unless a life-threatening emergency exists. Seek the advice and assistance of any available experienced intubators. Consider having a surgeon available for surgical airway intervention if loss of the airway is a serious risk. If the expertise to manage a particular child’s airway is not available, and conditions permit, transport the child to a more optimal location.
What Resources Do You Have?
We were doing the case in the small, rather cramped, CT scanner area —which was a good 5 minute run from the main OR. I therefore needed to anticipate any equipment or personnel I might need before starting to avoid any dangerous delays.
Prepare Plan A
Although there was visible swelling and mild stridor, she was breathing comfortably with an oxygen saturation of 97%. Based on physical exam, I believed that I could ventilate her.
Although she had a preinduction IV placed, I planned an inhalational mask induction to allow her to continue to breathe spontaneously. With induction of unconsciousness, I knew that she would lose some pharyngeal muscle tone and ventilation might become more difficult. If I gave muscle relaxant, the resulting paralysis, and total loss of pharyngeal muscle tone might potentially induce total airway obstruction. Allowing her to breath on her own would let me gradually test her airway as she got deeper.
I had propofol, atropine and succinylcholine drawn up and ready just in case. I also had a pediatric bristojet of epinephrine unopened but available. A print out of all of the emergency drugs with dosages and volumes calculated for my patient was on my cart.
I enlisted the help of the mother to avoid panicking the child and making her struggle. I told Mom in advance the risks and what I was doing to minimize those risk. I told her what she could expect to see, what I needed her to do, and when I was going to ask her to leave the room. I also identified the support person in the room who would be in charge of taking Mom out.
Secure The Airway: GlideScope
I planned to intubate using a pediatric GlideScope Video Laryngoscope (GVL, Verathon) because I expected airway distortion. Additionally, as rupture of the abscess could be catastrophic, the GVL would minimize manipulation needed during laryngoscopy.
I planned to start with a GVL 2.5 but had a GVL 2 available. The shape of the pediatric GlideScope blade varies significantly with the size to accommodate the differences in pediatric airway anatomy.
Four sizes of pediatric GVL are currently available, and pediatric-sized blades are usually chosen by patient weight:
- GVL 0 for less than 1.5 kg
- GVL 1 for 1.5-3.6 kg
- GVL 2 for 4-20 kg
- GVL 2.5 for 10-28 kg
Tip For Pediatric GlideScopes
You can use the variation in shape to help with the airway anatomy of your particular child. Selecting the next size smaller than recommended for that weight child may provide a better view (4,5). It allows more ability to manipulate the angle and depth of the blade in the small pediatric mouth. As you can see in the table above there is some overlap in weight based blade selection. You should optimally have both sizes available and be ready to switch blades if the first one doesn’t give good visualization.
Other tips for using Glidescopes can be found here:
- GlideScope: Tricks for Successful Intubation
- Awake Intubation With The GlideScope
- Intubating With A Pediatric Glidescope
The stylet should match the curve on the GlideScope blade. For children older than 4 years, it’s often better to use a stiffer wire stylet rather than the highly flexible slip guide type. The latter is often not long enough or stiff enough to guide an ETT larger than size 5.
Endotracheal Tube Choice
Normally, for a 5 year old I would choose an uncuffed size 5 to 5.5 based the formula:
- uncuffed formula: age divided by 4 plus 4
- cuffed formula: age divided by 4 plus 3
However, I planned to use a smaller than average tube. I expected the upper airway and larynx to be swollen and narrowed. Other considerations included:
- use of a cuffed tube to protect her lungs from potential rupture of the abscess
- length of the tube, to ensure the cuff was placed below the cricoid ring, to avoid injury to recurrent laryngeal nerves
- lumen size, to allow suctioning of purulent secretions if abscess ruptured before intubation
- optimal size for prolonged intubation, if extubation not possible
After weighing all of these parameters, I chose a size 4 cuffed endotracheal tube as my primary tube. My final decision was made because I wanted to choose a tube that I was pretty certain would pass first time. I did NOT want to have to exchange it or do multiple laryngoscopies. I had smaller and larger size tubes available.
Extra Pair(s) of Experienced Hands
One of my anesthesia colleagues joined me in case of difficulty. Having another pair of trained hands is advisable when managing a difficult airway. They can offer advice, prepare equipment and give you a hand with mask fit, among other things.
The interventional radiologist was present. The Head and Neck surgeon on call was also close by in-house and free to come at a moments notice.
Plans B and C
I had standard Miller 2 and MAC 2 laryngoscope blades set up. Sometimes attempting standard direct laryngoscopy is the fastest choice if an elective glidescope intubation fails.
The difficult airway cart was just outside the radiology suite, with a pediatric fiberoptic scope out and ready to go.
I also had an LMA available as an emergency airway, although I thought that the distortion from the abscess could make its use unlikely to succeed.
Plan For the End At the Beginning
Always plan for extubation before you start the case. Although we felt that we should be able to extubate this child once the abscess was drained, that was not certain. I alerted the Post Anesthesia Care Unit (PACU) charge nurse about the case before we started so that she would know the child’s risk factors.
Our hospital did not have a Pediatric Intensive Care Unit (PICU). If the child had to remain intubated, then one of the anesthesia team would need to remain with the child in the PACU until extubated. If she required prolonged ventilatory support then we would need to arrange for her transport to the local Children’s Hospital.
You can appreciate that these are discussions best held in advance, and definitely not sprung on the recovery team as a surprise challenge to staffing and skill set.
Always have the equipment needed to reintubate at the bedside whenever you extubate. Have an assistant available to help. Remember that reintubation is often more difficult than the initial intubation, as a result of edema from IV fluid administration, intubation trauma, or surgical insult.
I bolused the child before starting with 20 ml/kg of LR to minimize any dehydration that might cause hypotension.
Her mother was present in the scanner room and held her hand while I induced anesthesia. I sent the mom to the waiting area as soon as the girl’s eyes closed.
Because she was at high risk for laryngospasm, it was important to ensure a deep plane of anesthesia before laryngoscopy. I waited a five full minutes giving her high concentration sevoforanne until end-tidal sevoflurane showed a deep, consistent level of anesthesia. In the old days, prior to our ability to measure end-tidal agent concentrations, it was common to wait a full 10-15 minutes during an intubation for epiglottitis.
As it was easy to ventilate her, I took over her breathing and hyperventilated her to apnea just prior to laryngoscopy. I then visualized using the GlideScope Video Laryngoscope (GVL) 2.5, as per weight recommendations. I was not able to obtain a good view of the larynx. I switched to a GVL 2, the next smaller size, and immediately had a good view of the larynx. Intubation was easy and the case proceeded without difficulty.
The interventional radiologist was able to drain the abscess percutaneously, without contaminating the airway. We were able to extubate the child without difficulty. We transported her to the recovery room with her mother where we observed her over several hours. Stridor resolved and she was transferred to the pediatric ward.
There was clearly a lot of thought and preparation. But assessing the patient, gathering supplies, and arranging back up/support personnel, was accomplished in about 20 minutes. Because the child was not in distress I had the luxury of taking that time and doing a lot of the prep myself.
However, had the child been in distress, I would have had to rely more heavily on my team to help me expedite the process to gather equipment, supplies and personnel . Teamwork and communication are essential for both prevention of problems and management of emergencies. If your team doesn’t know the plan, they can’t help you.
May The Force Be With You
- 10 Common Pediatric Airway Problems and Their Solution, Whitten CE, Anesthesiology News Annual Airway Review, August 2019-2020
- Cook TM, Morgan PJ, Hersch PE. Equal and opposite expert opinion. Airway obstruction caused by a retrosternal thyroid mass: management and prospective international expert opinion. Anaesthesia. 2011;66(9):828-836.
- Always Prepare For Failure: 10 Rules For Approaching Difficult Intubation, Whitten CE, Anesthesiology News Annual Airway Review, August 2018-2019
- Lee JH, Park YH, Byon HJ, et al. A comparative trial of the GlideScope video laryngoscope to direct laryngoscope in children with difficult direct laryngoscopy and an evaluation of the effect of blade size. Anesth Analg. 2013;17(1):176-181.
- Armstrong J, John J, Karsli C. A comparison between the GlideScope video laryngoscope and direct laryngoscope in paediatric patients with difficult airways—a pilot study. Anaesthesia. 2010;65(4):353-357.