Asthma
Key Feature 2: In a child with acute respiratory distress, distinguish asthma or bronchiolitis from croup and foreign body aspiration by taking an appropriate history and doing a physical examination.
Skill: Clinical Reasoning, Selectivity
Phase: History, Physical

Croup
Key Feature 3: In any patient presenting with respiratory symptoms, look specifically for the signs and symptoms that differentiate upper from lower respiratory disease (ex: stridor vs. wheeze vs. whoop). 
Skill: Clinical Reasoning
Phase: History, Physical

In a patient presenting with respiratory symptoms, it is important to look for signs and symptoms that differentiate upper from lower respiratory disease as this affects the workup to determine the underlying pathology.

As it pertains to the pediatric population (croup is usually a disease of childhood), my differential diagnosis for upper airway problems causing respiratory distress includes:
        1. Foreign body aspiration
        2. Anaphylaxis/angioedema
        3. Infection (croup, epiglottitis, tracheitis, retropharyngeal abscess)
        4. Trauma (mechanical, chemical)
        5. Other (structural, metabolic, neurological)

And my differential diagnosis for lower airway problems causing respiratory distress includes:

1. Bronchiolitis
2. Pneumonia, atelectasis
3. Asthma, bronchospasm
4. Respiratory distress syndrome of the neonate
5. Tracheo-esophageal fistula
6. Pulmonary embolus 

There is a table from UpToDate that gives an overview of the signs that may differentiate signs of upper airway obstruction from lower airway disease. It may be a bit more difficult to use symptoms as a method of distinguishing upper from lower airway disease, particularly in children, as cough, dyspnea, and respiratory distress (the main presenting symptoms for respiratory disease) may present in both processes. 

In a previous post I mentioned how breath sounds can be a very useful clinical sign to distinguish various locations and types of disease pathology. Stridor and stertor both signify upper airway obstruction, while wheeze and crackles tend to signify lower airway pathology. In the Key Feature for this post, it also makes mention of a "whoop" sound, classically known a the sound produced in "whooping cough," otherwise known a pertussis. It sounds like this:

According to some dude Peter Wehrwein, "People with pertussis make a whooping sound because they run out of breath after coughing hard several times in row; the whoop is the sound of a sudden, hard inhale." I have never encountered this sound, in keeping with the fact the pertussis vaccine is now part of the routine child immunization schedule and is now a rare disease. That being said, it is not eradicated either, so if the "whoop" sound is heard, having my ears perked up for suspicion of pertussis would be warranted.

Key Feature 1b: In patients with croup: provide that assistance when indicated.
Skill: Clinical Reasoning
Phase: Treatment

Key Feature 5: In patients with a diagnosis of croup, use steroids (do not under treat mild-to-moderate cases of croup). 
Skill: Clinical Reasoning
Phase: Treatment

Key Feature 6: In a patient presenting with croup, address parental concerns (ex: not minimizing the symptoms and their impact on the parents), acknowledging fluctuating course of the disease, providing a plan anticipating recurrence of the symptoms. 
Skill: Clinical Reasoning, Communication
Phase: Treatment, Follow-up

In a patient who is found to have airway compromise and/or respiratory distress, as may be the case in a kiddo with croup, it's important to 

1. Know your basic approach to managing the unwell patient (ABCs)
2. Know what the initial treatment is to reverse this life-threatening cause of distress

The basic approach to the ABCs is to look for signs of distress from airway, breathing, and circulatory compromise, among others, and provide life-preserving resuscitation maneuvers as indicated. In a patient who is in distress from croup, they are likely to present with airway and breathing difficulties. When it comes to airway resuscitation, general interventions to consider are as follows:

1. Basic airway management if you suspect oropharyngeal obstruction:  This includes positioning the patient to optimise air flow, sweep and suction maneuvers, and the use of airway adjuncts, as indicated.
2. Definitive airway management: Endotracheal intubation, or other rescue methods of securing the airway, as needed.

And when it comes to resuscitation of breathing, general interventions to be considered as follows: 

1. Positioning
2. Ventilation support
3. Supplemental oxygen
4. Seeking help from a respiratory therapist

Now let's approach the above menu in the setting of a child who presents with distress from croup. It would be likely that they have stridor, which is a sound that indicates upper airway obstruction at the level of the larynx. Note that this sound is distinct from the sound of stertor (which is essentially the same sound as snoring), which also indicates upper airway obstruction but that which occurs at the level of the oropharynx rather than the larynx. So in the child with suspected croup, with an audible sign of laryngeal obstruction rather than oropharyngeal obstruction, we would recognize that basic airway management maneuvers are not indicated. Would we consider definitive airway management? If the child was already decompensating and the distress was so severe that they were unable to maintain their airway or were at impending risk of this, then yes, we would definitely consider placement of a definitive airway. 

Assuming the patient has distress from croup that is significant but not warranting placement of a definitive airway just yet, we would move on to our options for supporting the patient's respiration. In a patient with severe respiratory distress, sitting upright is generally the ideal position to optimise breathing, and the head of the patient's bed would be raised to support this. Note that if the patient feels there is another position that best supports their breathing, they should not be prevented from assuming this position instead. This is particularly important when it comes to the child with respiratory distress, as any increased discomfort may further agitate them and lead to even greater work of breathing, thereby increasing their demand for oxygen and putting them at increased risk of respiratory decompensation.

​After optimising positioning, the next maneuver to consider is ventilation support. This would be indicated for the child who has decompensated after prolonged respiratory effort, which can happen in severe circumstances. Much like intubating the airway, this is a maneuver that must be considered if the situation is dire enough, and if so cannot be delayed as it can make the difference between life and death. If the child is still supporting their own breathing effort, we would move on to providing supplemental oxygen if indicated, which would be if pulse oximetry showed their oxygen saturation as less than 95%. The choice of delivery system would depend on the severity of their hypoxia, and could range from providing blow-by oxygen, to delivering oxygen by nasal prongs, simple face mask, or non-rebreather. If supporting a patient's respiratory effort, you may also find it very helpful to have a respiratory therapist involved in the management of this.

Now once the most critical life-saving airway and breathing resuscitation measures are underway, it is important to quickly consider if there are any rapidly reversible life-threatening causes for the airway and breathing difficulties. In a patient with stridor secondary to a suspected infection and the associated airway swelling it causes (as may be the case with croup, epiglottitis, or bacterial tracheitis) this would call for a dose of epinephrine, which can start to act within seconds to minutes to decrease swelling and corresponding obstruction. The dose to prescribe is: racemic epinephrine 0.05 mL/kg (max dose 0.5mL) diluted to 3mL with NS nebulized over 15 min q1-2h PRN. 

For patients who present with croup, regardless of whether or not they are severe enough to warrant epinephrine, they do merit a dose of dexamethasone (0.6 mg/kg dose). This is not as important to give quickly like epinephrine in the case of severe acute respiratory distress from croup, because it takes a few hours to have an effect, but it once it does start working it last for up to three days. It deceases inflammation and swelling of the affected upper airway tissue, decreasing signs of airway obstruction and reducing the respiratory symptoms that come with. There is minimal harm from giving a one-time dose of dexamethasone, and there is much benefit, both for the patient and the health care system as it significantly decreases the number of repeat visits to the ED for the same bout of illness (per the UpToDate article, "Croup: Pharmacologic and supportive interventions" (2018)).

The fact that I mentioned that giving dexamethasone decreases repeat presentations for medical care for the same bout of croup suggests that presenting repeatedly for croup is a thing. If you haven't yet heard a child with stridor, then I encourage you to watch the video clip I plan to put in my next post. Quite frankly, it can sound quite scary, and it can be a real cause for concern when severe. On the other hand, mild croup is extremely common, and does not pose much of a threat at all unless it worsens. But it is hard for parents to know when exactly they ought and ought not be worried, because even mild croup in a child may appear worrisome to a parent who is not used to seeing their child without any sort or respiratory symptoms. Much of the management of croup then involves parental education about what are the differences between mild and severe croup, and what to do when the croup is severe and when it isn't. The UpToDate patient handouts (among many other useful patient resources) on croup are one tool to help parents know when and when not to worry from a medical point of view. All of the UpToDate handouts are free online at can be found here.

I have attached the UpToDate Croup handout below, as it provides a framework for important thing to consider when counselling a parent on taking care of their child with croup.

Key Feature 1a: In patients with croup: Identify the need for respiratory assistance (ex: assessABCs, fatigue, somnolence, paradoxical breathing, in drawing) 
Skill: Selectivity, Clinical Reasoning
Phase: Hypothesis generation, Diagnosis

Key Feature 2: Before attributing stridor to croup, consider other possible causes (ex: anaphylaxis, foreign body (airway or esophagus), retropharyngeal abscess, epiglottitis). 
Skill: Clinical Reasoning, Selectivity
Phase: Hypothesis generation, Diagnosis

Key Feature 4: In a child presenting with a clear history and physical examination compatible with mild to moderate croup, make the clinical diagnosis without further testing (ex: do not routinely X-ray). 
Skill: Clinical Reasoning, Selectivity
Phase: Diagnosis, Investigation

It wouldn't be a pediatric emergency medicine rotation if I didn't have at least 3 cases of croup on my first shift. If I have the opportunity to learn any one thing on this rotation, it's how to assess a child with respiratory distress.

If a patient appears unwell at all, it's always important to start with the ABCs, and when the patient is unwell because of croup, it is the A in that emergency response acronym that is most affected: Airway. This is because croup, also known as laryngotracheobronchitis, causes inflammation of all of those upper airway structures, leading to hoarse voice, inspiratory stridor, and a "barky" cough. If the inflammation is significant enough, it can actually be a life-threatening airway emergency, though this is certainly the exception. 

In any child who appears unwell, I start by assessing the ABCs. The features I look for when assessing for airway compromise and respiratory distress, as I may expect to see if in a child with croup, are:

Airway

1. Altered level of consciousness (ex: somnolence, hypotonia) or agitation (as in someone who is stressed because they're choking or can't breathe)
2. Cyanosis
3. Sounds (ex: stridor, as from a severe upper airway obstruction, or silence, which could indicate  a complete upper airway obstruction)

Breathing

1. Tripod posturing, tracheal tug
2. Accessory muscle use, nasal flaring, grunting
3. Indrawing (supracostal, intercostal, subcostal), paradoxical abdominal breathing
4. Respiratory decompensation (from prolonged increased work of breathing, which may manifest as fatigue or altered level of consciousness)

If you read my blog post from my sudden arrest from sleep way too early this morning, you'll know that I've spent way too much time lately trying to study around respiratory distress. This makes addressing this priority learning topic easy, as I've already done all of my homework for it, but I also happened to get pimped by my preceptor on the topic and knew what was up. Specifically, I was presenting a case of one of the patient's I had gone in to assess who I believed had a diagnosis of croup. He then asked me if I had considered what other possibilities may be going on. My differential included the common and rare but serious causes of stridor in a child, and why they were unlikely given my patient's presentation:

• Foreign body aspiration (no history of ingestion or sudden choking/wheeze)
• Anaphylaxis (usually involves a skin reaction, though not always, but at least 2 body systems must be implicated, which was not the case in my patient)
• Trauma (no history of injury or other signs of injury on exam)
• Croup (barky cough, inspiratory stridor, hoarse voice, worse when laying down at night, better when in cold air - YUP)
• Epiglottitis (no drooling, immunizations up to date)
• Bacterial tracheitis (no sudden high fever or acute symptom onset, nontoxic appearance)
• Peritonsillar abscess (exceptionally more rare than croup, no risk factors)
• Retropharyngeal abscess (exceptionally more rare than croup, no risk factors)

Ta-da! With each one, I gave reasons for why I thought it was lower on my DDx than croup, which was really just my own reasoning as moments before I had worked through this thought process trying to rule out all of the other non-croup entities. The studying pays off from time to time, how nice! My preceptor was convinced, and thought this was just another kid with a typical presentation of moderate severity croup. With a low pretest probability of the more worrisome reasons for upper airway obstruction and for why a neck or chest xray would be obtained, we diagnosed and managed the child without a single poke or image for confirmation. He got some dexamethasone and not one, but two popsicles, and he went on his way with some bye-byes and a fist pump. Another happy croup ending.