upper airway inflammatory Diseases
cHaPTer ouTline
INTRODUCTION
Respiratory therapists working the emergency room during the winter are likely to hear a barky cough in between attempts to cry from young children. This barky cough is the most recognizable symptom of croup.
November through March is croup season, and many children arrive in the emergency room needing medical attention. A barky cough is a clear indication of croup; however, it is necessary to distinguish between croup and epiglottitis. This chapter will define and compare each condition and discuss the role that respiratory therapists play in the treatment phase of each condition.
DEFINE
Croup, also called laryngotracheitis, is viral condition that affects the subglottic tissue causing it to swell and obstruct the airway. Most often it is caused by the parainfluenza virus. According to Dr. James Cherry, (2008) croup is an illness that occurs in children under 6 years of age.1 It is more prevalent in boys and occurs most often between 7 months and 36 months of age.1 Table 6-1 illustrates the difference between croup and epiglottitis. Croup is either spasmodic croup or acute laryngotracheitis.
Epiglottitis is a bacterial infection that causes the swelling of the supraglottic structures of the airway. The epiglottis is enlarged and has a cherry red coloration. In the majority of cases, epiglottitis is caused by Haemophilus influenzae type B. Epiglottitis can cause partial or complete blockage of the airway. Kent Whitaker, in his neonatal/pediatric book, describes epiglottitis as the inflammation of the epiglottis, vocal cords, the base of the tongue, and the aryepiglottic folds.2 Since the introduc- tion of the Haemophilus influenzae type B vaccine, there have been very few cases of epiglottitis in children. Epiglottitis does occur in adults, but not necessarily due to Haemophilus influenzae type B: it is caused by other organisms found in older children or young adults who may not have received the Haemophilus influenzae vaccine.
DESCRIBE
Historically, croup or croup-like illnesses were believed to be diphtheria.1 In modern medicine, viral croup is described as either laryngotracheitis
or spasmodic croup, characterized by the swelling of the lateral walls of the trachea below the vocal cords.1 Spasmodic croup typically occurs at night with no evidence of fever or inflammation. Acute laryngotracheitis is a more serious illness with evidence of inflammation of the larynx and tracheal and a low-grade fever. On the other hand, bacterial croup, more precisely known as laryngotracheobronchitis (LTB) or laryngotra- cheobronchopneumonitis (LTBP), is characterized by inflammatory cells in the tracheal wall.1 Both LTB and LTBP are described as inflammation of the larynx, trachea, and bronchi. Both conditions can lead to airway obstruction. Common symptoms of croup include inspiratory stridor, barking cough, hoarseness, retractions, use of accessory muscles, and low-grade fever.
Epiglottitis is described as an inflammation of the soft tissue sur- rounding the epiglottis, which causes a blockage of the trachea, thus prevents breathing. This condition appears within 4 to 12 hours and is accompanied by high fever and muffled voice (see Table 6-1 for compari- son of croup and epiglottitis). Patients with epiglottitis do not have the characteristic barky cough seen with croup, and this condition is not lim- ited to seasonal occurrence. Common symptoms of epiglottitis include drooling, absence of a cough, sitting in a “tripod” position, inspiratory
Table 6-1 Highlights of the Differences Between Croup and Epiglottitis
epiglottitis croup
Age 3 to 6 years 6 months to 3 years
Rate of onset Rapid, often within hours Slow (2 to 3 days)
Infectious origin Haemophilus influenzae type B Parainfluenza virus or mycoplasma pneumoniae and respiratory syncytial virus
Clinical presentation
High fever, anxious leaning forward, drooling, low-pitch stridor, muffled voice, retractions and nasal flaring, sitting in a tripod position, and no barky cough.
May be afebrile or febrile. Hoarse barky cough, tight upper airway inspiratory stridor, runny nose, and retractions.
Chest radiograph Swollen, edematous epiglottis (thumb sign, see figure 6-1), and supraglottic structures seen on lateral neck film
Narrowing of the subglottic airway (hourglass or steeple sign, see figure 6-2) seen on anterior-posterior (A-P) neck film
Occurrence Any season Usually winter
stridor, and high fever. On chest x-rays, epiglottitis looks like a thumb- sign (see Figure 6-1).
DISTINGUISH
Although croup and epiglottitis are the main culprits of upper airway inflammatory conditions, care must be made to distinguish croup and epiglottitis from the following diagnoses:
Foreign-body airway obstruction (FBAO)—blockage of the airway
• caused by any innate item small enough to be swallowed. Foreign- body airway obstruction usually occurs suddenly, with no fever or other signs of infection.1 Lateral neck films may not be helpful in identifying the location of the object because most objects cannot be seen on chest x-rays. FBAO occurs more often in children from 7 months to 4 years and is the leading cause of death in children under 6 years.3 Common symptoms of FBAO are choking, retractions, strug- gling to breathe, gasping for air, and absent breath sounds.
fiGure 6-1 Thumb sign seen in epiglottis
Bronchiolitis—an inflammatory disease of the bronchioles caused
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by respiratory syncytial virus (RSV) or parainfluenza viruses. It is the most common cause of lower respiratory tract infections in children under 2 years.3 It occurs in the fall and winter and is highly con- tagious. Common symptoms of bronchiolitis are cough, increased respiratory rate, low-grade fever, retractions, wheezing, and cyanosis.
RESEARCH
Kristine Rittichier et al. describe croup as an upper airway obstruction produced by subglottic edema.1 Croup is caused by a viral organism, the most common of which are parainfluenza types I and III and respiratory syncytial virus (RSV). The symptoms appear within 1 to 2 days after the presentation of the seal-like barky cough. Figure 6-2 shows a “steeple sign” representing a narrowing of the airway—a classic sign of croup.
Most symptoms usually resolve over a period of 7 to 10 days. Perri Klass, MD, reports in the New England Journal of Medicine that when she hears the classic signs of croup over the telephone, she makes the following recommendations: “Children with respiratory distress go to the emergen- cy room, and other children into a steamy bathroom to see whether the moisture helps.”4 Dr. Klass’s discussion of croup affirms our understand- ing in that croup is self-limiting, usually mild, and will resolve within 1 to 2 days. In moderate and severe cases, research shows that cool mist does little if any to resolve the symptoms,5 although the use of cool mist continues, particularly in mild croup. The treatment section will discuss how cool mist is administered for differing age groups.
Steroid therapy is an area that researchers have focused on.6,7,8,9 For example, during the past 15 years, corticosteroids have been the treat- ment of choice to manage croup. The debate among clinicians is whether to give every symptomatic child steroids. Dr. Klass reports that not every child will need corticosteroids to manage his or her symptoms. However, if a physician believes that administering corticosteroids will shorten the length of the illness, ultimately speeding recovery, then he or she is likely to give rather than withhold. For moderate to severe symptoms of croup, research supports using steroids with the intent to decrease inflamma- tion around the subglottic tissue, which will decrease the symptoms of
fiGure 6-2 Steeple sign or hourglass sign seen in croup
moderate to severe croup. Dr. David Johnson et al. compared nebulized budesonide to intramuscular dexamethasone.7 The results showed that both budesonide (Pulmicort) and dexamethasone (Decadron) offered significant clinical improvement, with dexamethasone providing the greatest improvement.7 It is well documented that using steroids reduces the need for hospitalization. A review of three studies done by Dr. Geel- hoed and his colleagues published in the British Medical Journal compared nebulized budesonide to oral dexamethasone.8,9 They found that nebu- lized budesonide and oral dexamethasone were significantly better than placebo in reducing hospital stay and reducing croup scores; however, they also found that oral dexamethasone was preferred over nebulized budesonide.8,9 Children who present with severe symptoms of croup are likely to be treated with nebulized racemic epinephrine (microNefrin or Vaponefrin). Racemic epinephrine, an alpha 1 adrenergic agent, causes vasoconstriction that is critical in decreasing the inflammation in pa- tients who have been diagnosed with severe croup. Patients who receive this treatment are likely to be admitted to the hospital for a minimum of 24 hours. This is due in part to the risk of rebound edema, typically seen 30 to 90 minutes after racemic epinephrine is given.10 Racemic epi- nephrine helps smooth out the bronchial walls and reduces edema and swelling. Nebulized racemic epinephrine is given every 1 to 2 hours, with close monitoring to watch for signs and symptoms of impending respira- tory failure.
Historical facts
An interesting fact about epiglottitis was found in the monologue “Death of a President.” It was December 1799 and the first U.S. president, George Washington, was “preparing to die.” Three physicians waited at his bedside trying to determine how to save him, as he lay struggling to breathe.11 It was difficult to know at the time how to diagnose epiglottitis because it had not been defined in the medical literature. It was after Washington’s death that epiglottitis, known then as cynanche trachealis, which means “dog strangulation,” was determined to be the malady that killed George Washington. Elisha Cullen Dick, a physician at Washington’s death, identified epiglottitis as
“inflammation of the glottis, larynx, or upper part of the trachea … a rare occurrence … [producing]
such an obstruction of the passage of air, as suffocates, and thereby proves suddenly fatal.”11
Although epiglottitis is less common than croup, it has not been totally eradicated in modern medicine. Since the introduction of the Haemophi- lus influenzae type B vaccine, epiglottitis is less common in young chil- dren, yet there are still cases of epiglottitis in older children and young adults.
Epiglottitis is not as prevalent as it once was; however, two cases of pediatric acute epiglottitis are described in the literature by Low et al. at the National University Hospital in Singapore from 1992 to 2001.12 Both children were treated for epiglottitis and provided with the Haemophilus influenzae type B vaccine. Low et al. stated that acute epiglottitis is rare in Singapore, yet when it occurs it can be life-threatening. They further pointed out that because epiglottitis is less common, medical clinicians must remain abreast of the seriousness of this condition.
TREATMENT
Supportive therapy has been shown to be an effective means of treating patients with croup. Most parents are quite anxious when having to care for a child with croup. Keeping a parent informed of their child’s condi- tion lessens their anxiety. Therapeutics used to treat croup include cool mist, oxygen therapy, pharmacology therapy, and positive pressure ven- tilation in very severe cases of croup. Table 6-2 illustrates the various treat- ment options available for patients with croup. One or more therapeutics may be used in the treatment of children with croup.
Treatment options for croup are as follows:
Humidity therapy—Cool mist through a face mask or as blow-by 1.
to the face is recommended only in mild cases of croup. The use of mist tent is no longer recommended.
Corticosteroids—Nebulized budesonide (Pulmicort) has shown ef- 2.
fectiveness in managing croup. The nebulized dose reported in the research study from Dr. Geelhoed was 2 mg,8 which is four times the typical dose of 0.5 mg Pulmicort commonly used on the general pediatric units. Dexamethasone (Decadron) can be given in nebu- lized form; however, it is usually given either orally or intramuscu- lar. Most research shows that 0.6 mg/kg of Decadron is administered to manage symptoms of croup.
Table 6-2 Treatment Options for Croup and Epiglottitis
Type of Therapy croup epiglottitis
Humidity therapy Cool aerosol mist Face mask Blow-by
Oxygen therapy may be required.
figure 6-3 shows a mist tent used for cool mist. figure 6-4a-b shows a blow-by for the administration of cool mist with and without a mask.
Cool aerosol mist Blow-by
Oxygen therapy may be required.
Medication Nebulized Pulmicort
In the emergency room 2 mg as ordered On the general pediatric unit 0.5 mg BID Nebulized racemic epinephrine In the emergency room and general pediatric unit 0.05 ml of 2.25% solution Intravenous or intramuscular corticosteroids 0.6 mg per kg of dexamethasone
Nebulized racemic epinephrine In the emergency room and general pediatric unit 0.05 ml of 2.25% solution following extubation if necessary
Antibiotic therapy Ceftriaxone 80 mg per kg per day
Positive pressure ventilation
In mild cases, not likely.
In severe cases with evidence of pending respiratory failure, intubation and mechanical ventilation may be necessary.
In severe case with evidence of pending respiratory failure, intubation and mechanical ventilation may be necessary.
Intubation should be done in the operating room with a skilled anesthesiologist.
Tracheostomy may be necessary.
fiGure 6-3 Mist tent with cool mist
fiGure 6-4 Cool mist (a) with a mask and (b) without a mask a
b
Racemic epinephrine (microNefrin or Vaponefrin)—This is given in 3.
nebulized form. Typical dose is 0.05 ml of 2.25% solution. It can be given as often as every 2 hours as needed. Children who receive ra- cemic epinephrine are monitored for a longer period of time before being discharged to home or admitted to the hospital for overnight observation.
Positive pressure ventilation—It has been reported that 3% to 6% of 4.
children with croup require intubation.3 Severe croup that pro- gresses to respiratory failure, as evidenced by an acute rise in PaCO2 greater than 50, a decreased pH less than 7.25, and decreased PaO2
less than 60 on more than 50% of oxygen, will need to be intu- bated.
Treatment options for epiglottitis are as follows:
Keep the child calm. It is better for the child to remain with the 1.
parents to lessen the anxiety.
Provide cool mist as blow-by. Cool mist with oxygen therapy may 2. be required. The one benefit to cool mist is that it helps to liquefy
the mucus, which may prevent mucus plugging.
Prepare for intubation and resuscitation. It is best to take a child to 3.
the operating room where a tracheostomy or cricothyroidotomy can be performed, if necessary.
Prepare to ventilate with a mechanical ventilator in case the child 4.
requires intubation. If positive pressure ventilation is required, ven- tilate with the least amount of positive pressure.
Obtain sputum and blood cultures.
5.
Provide required antibiotic therapy.
6.
Determine weaning readiness. Ensure there is an audible leak 7.
around the endotracheal tube.
Monitor closely following extubation. Nebulized racemic epineph- 8.
rine may be needed following extubation.
SUMMARy
This chapter compared croup and epiglottitis—conditions that affect the upper airway, causing narrowing and the potential for complete blockage of the airway. Even though there are similarities, there are many more
differences between the two. It is those differences that prompt clinicians to be particularly careful in rendering the correct diagnosis. Each con- dition requires quick action. Children with epiglottitis tend to exhibit worsening respiratory symptoms and require immediate relief, should se- vere airway obstruction ensue. Children with mild croup are not usually admitted to the hospital, although they tend to come to the emergency room more often. Croup tends to be seasonal, whereas epiglottitis is year- round. The role of the respiratory therapist becomes more evident when either condition worsens to the point of respiratory failure. This is made clearer when mechanical ventilation is required.
Croup
Croup is an airway inflammatory condition that can be categorized
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as mild, moderate, or severe. It can be caused by any number of viral organisms.
It is the swelling of subglottic tissue causing airway obstruction.
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It is characterized with a seal-like barky cough.
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Symptoms get worse at night.
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Severe cases of croup are typically treated on the inpatient unit of
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the hospital.
Epiglottitis
Epiglottitis is swelling of the soft tissue surrounding the subglottic
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structure.
It is characterized by its rapid onset and high-grade fever.
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It has no distinctive cough, and often the patient will sit in the
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characteristic tripod position.
Epiglottitis cause complete blockage of the airway.
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This condition is considered a medical emergency.
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Although croup and epiglottitis have many similarities, they remain two very distinct conditions that require medical management unique to its symptoms. Respiratory therapists are quite familiar with the symptoms of croup because this condition is more prevalent. Epiglottitis is less com- mon than croup since the introduction of the Haemophilus influenzae type
B vaccine. Epiglottitis has not been terminally eradicated, but the inci- dence of epiglottitis in recent years of pediatric care is extremely low.
REFERENCES Cherry, J. (2008). Croup.
1. New England Journal of Medicine, 358, 384–391.
Whitaker, K. (2001).
2. Comprehensive perinatal and pediatric respiratory care (3rd ed.). Albany, NY: Delmar Thomson.
Kacmarek, R., Dimas, S., & Mack, C. (2005).
3. The essentials of respiratory care (4th ed.). St. Louis, MO: Mosby Elsevier.
Klass, P. (2004). Croup—The bark is worse than the bite.
4. New England Journal of Medicine, 351, 1283–1284.
Scolnik, D., Coates, A., Stephens, D., Da Silva, Z., Lavine, E., & Schuh, S. (2006). Controlled delivery of high vs low 5.
humidity vs mist therapy for croup in emergency departments: A randomized controlled trial. Journal of the American Medical Association, 295, 1274–1280.
Rittichier, K., & Ledwith, C. (2000, December). Outpatient treatment of moderate croup with dexamethasone 6.
intramuscular versus oral dosing. Pediatrics, 106 (6), 1344–1348.
Johnson, D., Jacobson, S., Edney, P., Hadfield, P., Mundy, M., & Schuh, S. A. (1998). Comparison of nebulized 7.
budesonide, intramuscular dexamethasone, and placebo for moderately severe croup. New England Journal of Medicine, 339 (8), 498–503.
Geelhoed, G., Turner, J., & Macdonald, W. (1996). Efficacy of a small single dose of oral dexamethasone for outpatient 8.
croup: A double blind placebo controlled clinical trial. British Medical Journal, 313, 140–142.
Kermode-Scott, B. (2004). Corticosteroids may be effective for most cases of croup, study shows.
9. British Medical
Journal, 329, 762.
Wheeler, D., Kiefer, M. Poss, W. (2000, June 1). Pediatric emergency preparedness in the office.
10. American Family
Physician, 61(11), 3333–3342.
Morens, D. (1999). Death of a president.
11. New England Journal of Medicine, 341(24), 1845–1850.
Low, Y., Leong, J., & Tan, K. (2003). Paediatric acute epiglottitis re-visited.
12. Singapore Medical Journal, 44 (10), 539–541.
Define
Define bronchiolitis
•
Define respiratory syncytial virus (RSV)
• Describe
Describe the clinical presentation of
• bronchiolitis
Describe who RSV bronchiolitis affects
• DisTinGuisH
Asthma
•
Bacterial tracheitis
• Croup
• researcH
Relevant research on bronchiolitis
•
Relevant research on RSV
•
TreaTMenT
Treatment options for patients with
• bronchiolitis
Treatment options for patients with RSV
•
Respiratory therapist’s role in the
•
management of patients with RSV bronchiolitis
Key TerMs Bacteremia Bronchiolitis Bronchodilator Meningitis
Respiratory syncytial virus (RSV) Ribavirin
Small particle aerosol generator (SPAG) Synagis