Pediatric Pearls – Bronchiolitis

Pathophysiology
  • Disorder that is commonly caused by a viral lower respiratory tract infection in infants
  • Characterized by acute inflammation, edema and necrosis of epithelial cells lining small airways and increased mucus production

  • Etiology
    • Coronavirus
    • Influenza
    • Rhino virus
    • Adenovirus
    • Parainfluenza virus
    • RSV (respiratory syncytial virus) – MOST COMMON!
  • Incidence – December-March
      • Most infections occur within first 2 years of life
      • About 40% experience lower respiratory infection during initial infection
      • RSV doesn’t grant permanent or long-term immunity – RE-INFECTION COMMON
      • The risk of significant viral or bacterial lower respiratory tract infection or pneumonia in an infant is low
  • Transmission
    • Direct contact with secretions
    • Young children shed virus for >2 weeks
    • 30-70% of household contacts become ill
  • Natural history
    • Begins with URI – Rhinorrhea, congestion, cough
    • Progresses to LRI in 2-6 days – Airway obstruction (tachypnea, wheezing, respiratory distress)
    • Variable and dynamic course
    • Lasts 2-4 weeks

Case

7-month-old male presents to the emergency room with his parents due to cough, runny nose, congestion and SOB that started 3 days ago.

VS: RR – 65, HR – 140, Temp – 99.1°F, O2 sat – 93% on RA


History
  • Typical Presentation of Bronchiolitis
    • Viral URI and cough with signs of lower respiratory tract infection
      • Work of breathing – grunting, nasal flaring, intercostal/subcostal retractions
      • Tachypnea
      • Wheeze
      • Coarse rales

Physical Exam
  • TIPS for a better exam
    • Upper airway obstruction can contribute to work of breathing
    • Suctioning and positioning may decrease the work of breathing and improve the quality of your examination
    • Counting respiratory rate over the course of 1 min is more accurate than shorter observations
  • Assess mental status, respiratory rate, work of breathing, oxygen status, listen to breath sounds, and assess hydration status


Diagnosis
  • DIAGNOSIS IS CLINICAL – NO LABS OR RADIOLOGICIAL STUDIES ARE NEEDED
    • When to consider CXR – if child has had >2 days of fever, an asymmetric chest exam, does not demonstrate improvement or has an unusually high O2 need
    • Diagnostic testing may be considered if:
      • Need cohorting – this is why we get testing for those we admit
      • Uncertain clinical diagnosis
      • Age <2 months
      • To assess for influenza – also needed this for those we admit

Management

Classify patient as mild, moderate, or severe based on the above physical exam

Mild Moderate Severe
1. Consider suction bulb

2. Discharge

1. Suction bulb

2. No bronchodilators

3. Discharge or admit

1. Suction bulb or wall

2. No bronchodilators

3. If no improvement consider starting high flow NC

4. Admit

  • Rehydration
    • IVF – moderately or severely dehydrated, secretions are thick and difficult to mobilize or severe respiratory distress
    • PO feeds – mildly to moderately dehydrated and can tolerate PO
  • Considerations for severely ill patients
    • Consider ONE TIME albuterol MDI trial if:
      • Severe respiratory distress OR
      • Increased risk for asthma
        • >12 months old, wheeze and once of the following
          • personal history of atopy or recurrent wheezing
          • strong family history of atopy or asthma
        • if responds to albuterol then consider switching to asthma pathway
      • Consider HFNC for significant hypoxia OR severe respiratory distress not improving with rigorous supportive care

 

Discharge criteria Admission criteria
–       Oxygen saturation >90%

–       Awake

–       Adequate oral intake

–       Mild/moderate work of breathing

–       Reliable caretaker

–       Able to obtain follow up care

–       MDI/spacer teaching if response to albuterol

–       Admit if discharge criteria not met:

o   Inpatient: Requires 02 or progression expected

o   OBS: Mild disease with expected LOS < 24 hours

o   ICU: Apnea, severe distress; Requires HFNC / CPAP / intubation

–       Infants with these risk factors present early in the illness have higher risk of progression:

o   Gestational age < 34 weeks

o   Respiratory rate ≥ 70

o   Age < 3 months

Additional Notes
  • Differentiate infants with probable viral bronchiolitis from those with other disorders
  • The above management points to do take into consideration patients with significant medical history such as congenital heart disease, anatomic airway defects, neuromuscular disease, immunodeficiency, chronic lung disease – ADMIT, HIGH RISK!
  • The physical exam will vary from minute to minute depending on child’s position, level of alertness, response to treatment – CONSTANTLY RE-EVALUATE!
  • If patient presents within the first couple of days, they may worsen and need admission at a later point – PARENT EDUCATION IS KEY!
    • Viral illness, treated by hydration and suction
    • Signs of respiratory distress
    • How to suction
    • When to suction
    • Frequent feeds and watch hydration status
    • Cough may last 2-4 weeks, do not use OTC cough and cold medications
    • Avoid tobacco smoke
  • NOT RECOMMENDED!
    • Albuterol – Wheezing is due to the airways being clogged with debris not bronchospasm
    • Racemic epinephrine
    • Corticosteroids
    • Chest physiotherapy
    • Montelukast
    • Antibiotics
    • Hypertonic Saline
    • Routine testing
    • Chest X-rays

References

  1. http://pediatrics.aappublications.org/content/134/5/e1474
  2. http://www.chop.edu/clinical-pathway/bronchiolitis-emergent-evaluation-clinical-pathway
  3. http://www.cochrane.org/CD001266/ARI_bronchodilators-for-bronchiolitis-for-infants-with-first-time-wheezing
  4. http://www.seattlechildrens.org/healthcare-professionals/gateway/pathways/

Special thanks to Dr. Hima Khamar, MD PGY-2 for her contribution to this month’s Pediatric Pearls!

Varicella in Pregnancy

Varicella-zoster virus

Varicella (chickenpox) is a highly contagious disease caused by primary infection with varicella-zoster virus (VZV)2 and may cause maternal mortality or serious morbidity

> Reactivation of latent infection, usually many years after the primary infection, may result in herpes zoster (shingles), a painful vesicular eruption in the distribution of sensory nerve roots2

> Both varicella (chickenpox) and zoster (shingles) are notifiable diseases. Notification must be made to the Communicable Disease Control Branch of SA Health as soon as possible and at least within three days of suspicion of diagnosis, by telephone or post.


Route of transmission

> Infection with chickenpox is transmitted through airborne / respiratory droplets and direct contact with vesicle fluid


Incubation period

> 10 to 21 days (may be up to 35 days in contacts given high titre zoster immunoglobulin, ZIG)


 Period of infectivity

> 48 hours before the onset of rash until crusting of all lesions (usually day 6 of rash)

> Infectious period may be prolonged in people with impaired immunity


Infection Control

> Non-immune staff should not care for the woman / baby infected with chickenpox

> Varicella (and herpes zoster) vesicles contain large numbers of virus particles. Ensure appropriate transmission based (standard, contact and airborne) precautions including:

> A negative pressure room with door shut (chickenpox and disseminated shingles)

> Immune staff in attendance

> Gloves, gown

> All dressing materials should be treated as medical waste

> Chickenpox and disseminated shingles use standard, contact and airborne precautions

> Localized shingles use contact precautions (only immune staff in attendance, single room, gloves, gown)

> In herpes zoster (shingles), transmission of infection usually requires contact with vesicle fluid; however, there is also evidence of respiratory spread. Localized shingles requires standard and contact precautions (not airborne precautions)


Susceptibility to varicella

> Women and babies susceptible to infection with VZV (may be severe or life-threatening) include:

> No history of varicella (chickenpox or shingles)

> Seronegative for varicella antibodies (VZV-IgG negative)

> No documented evidence of varicella vaccination 


Significant Exposure

> For the purpose of infection control and prophylaxis, significant exposure of a susceptible woman who is pregnant to varicella includes:

> Living in the same household as a person with active varicella or herpes zoster

OR

> Direct face to face contact with a person with varicella or herpes zoster for at least 5 minutes

OR

> Being in the same room for at least 1 hour

> Chickenpox cases are infectious from 2 days before rash until lesions crusted


Management of maternal exposure to varicella-zoster virus

History of previous chickenpox

> No action required

No or uncertain history of chickenpox

> Obtain serology for antibody status (VZV-IgG) (if practicable)

> ZIG if required should be given within 96 hours. Testing should only be done if ZIG would still be able to be given, if required, within this window


Within 96 hours from exposure

> Zoster immunoglobulin (ZIG) should be given to all seronegative women within 96 hours (see adult dose under ZIG dosage below)

> However there may be some limited effect out to as late as 10 days post exposure

> Advise to seek medical care immediately if chickenpox develops


More than 96 hours following exposure

> Oral aciclovir or valaciclovir (see dosage below) should be considered for women:

> In the second half of pregnancy

> With a history of an underlying lung disease

> Who are immuno-compromised

> Who are smokers

Note: Advise women to seek medical care immediately if chickenpox develops


Management of varicella-zoster in pregnancy

Less than 24 hours since appearance of rash

> Oral aciclovir 800 mg 5 times a day for 7 days OR oral valaciclovir 1 g three times a day for 7 days]

> Monitor at home

More than 24 hours since onset of rash

> No oral aciclovir / valaciclovir and monitor at home if:

> No underlying lung disease

> Not immunocompromised

> Non-smoker

> Monitor in hospital if any of the above risk factors

> Offer appropriate fetal medicine counselling


Complications

> Advise to seek medical attention for the following complications:

> Respiratory symptoms

> Haemorrhagic rash or bleeding

> New pocks developing after 6 days

> Persistent fever

> 6 days

> Neurological symptoms

> Give aciclovir 10 mg / kg every 8 hours for 7 to 10 days (IV followed by oral [see dosage below]) and administer supportive therapy

Consider caesarean section if:

> Signs of significant fetal compromise

> Evidence of maternal respiratory failure exacerbated by advanced


Risk of fetal varicella syndrome (FVS) after maternal VZV

Timing of maternal infection:

>Less than 12 weeks gestation-  0.55%

>12-28 weeks gestation- 1.4%

>More than 28 weeks gestation- No cases of FVS reported


Refer to maternal fetal specialist for prenatal diagnosis and counselling

> Detailed fetal ultrasound for anomalies is recommended at least five weeks after primary infection

> Repeat ultrasounds until delivery. If abnormal may consider fetal MRI

> VZV fetal serology is unhelpful

> Amniocentesis not routinely advised if ultrasound normal, because risks of FVS low but negative VZV PCR may be reassuring


Management of infants exposed to maternal varicella zoster

Maternal chickenpox > 7 days before delivery

> No zoster immunoglobulin (ZIG) required

> No isolation required

> Encourage breastfeeding

> No other interventions even if baby has chickenpox at or very soon after birth unless preterm < 28 weeks gestation or low birth weight < 1,000 g > Very preterm infants (≤ 28 weeks gestation) born with chickenpox should receive intravenous aciclovir 20 mg / kg / dose every 8 hours as a slow infusion (1-2 hours)

 

Thank you to Christine DeFranco PGY-4 EM Resident for this review of VZV in pregnancy!