viral bronchiolitis - cb

Peds Case: Viral Bronchiolitis

Christopher Betts, PGY I

Cc: cough and fever

HPI:15 month old female p/w 4 days of cough, fever, congestion, decreased PO intake. She has had one bout of post-tussive emesis, but no other vomiting.

Cc: cough and fever

HPI:Her mother has also noted the following over the past two days prior to admission: fever with a max of 101.6 F, decreased oral intake, two wet diapers over the last 24 hours, and a strange “noise” every time she breaths with increased belly breathing and nasal flaring. She brought her to Hillcrest ED two days prior and was sent home with two albuterol neb treatments. The mother administered the albuterol neb treatment but her daughter did not improve.

Cc: cough and fever

HPI:The morning of admission, the patient was brought again to Hillcrest ED with worsening symptoms. At the ED, she was noted to be hypoxic and received supplemental O2, orapred, and two doses of albuterol neb.

Cc: cough and fever

PMHx:• No diagnosis of asthma, but was given

albuterol for cough 3 months ago. • Hospitalized at 5 months old for ALTE, no

diagnosis at that time; no further episodes.Immunizations: Has not had her 12-mo. vaccFMHx: older brother with h/o RSVAllergies: NKDA

Cc: cough and fever

• SHx: stays at home with mother, but goes to church nursery. Lives with a 4yo and 2 yo siblings, mother, and cousin.

• Mother denies smoking or pets at home.

Physical exam

• T 97.9• R 44• P 139• BP 96/57• Sat 90% on 0.5L NC

Physical Exam• Gen: alert, moderate respiratory distress, tearful• HEENT: mmm, OP clear, no LAD, PERRL, EOMI• CV: RRR, no m/r/g• Resp: supraclavicular and subcostal retractions, nasal

flaring, grunting, coarse BS bi/l, no wheezing.• Abd: S, NT/ND, BS+, no HSM• Neuro: orients to sound; moving all extremities; alert.• Extr: cap refill <2s, warm to touch distally, no overt

rash/cyanosis/bluish hue, 2+ pulses in femoral and brachial.

Labs / studies

• ??

Labs / studies

• RSV (in ED): positive • Rapid flu A/B (in ED): negative• cbc: 18.0/11/32.9/393 Seg 23, Lym 61, Mon 16• CXR: hyperinflated, no infiltrates

Differentials:

......

Assessment

15 month-old female with 4 days of persistent cough, fever, incr’d work of breathing w/ positive RSV screen.

Bronchiolitis is a disorder most commonly caused in infants by viral lower respiratory tract infection. It is the most common lower respiratory infection in this age group.

It is characterized by acute inflammation, edema, and necrosis of epithelial cells lining small airways, increased mucus production, and bronchospasm.

Viral Bronchiolitis

• One of the most common lower respiratory tract infection in children younger than two years, and is often caused by RSV.

• Other common viral pathogens that cause bronchiolitis: human metapneumovirus, adenovirus, influenza, and parainfluenza.

RSV

• RSV is an enveloped, non-segmented, negative stranded RNA virus

• Member of Paramyxoviridae family• A & B subtypes• Dominant strains shift annually, accounting for frequent

reinfections• Incubation period ranges between 2 to 8 days.• Viral shedding ranges between 3 to 8 days.• The infection may continue up to 4 weeks in young

infants.

Pathophysiology

• A viral infection starts with its replication in the nasopharynx. A lower respiratory tract infection develops in 1-3 days via spread of the virus from the nasopharynx to the small bronchiolar epithelium lining the small airways within the lungs.

• What can result is edema, incr'd mucus production, and eventual necrosis and regeneration of epithelial cells. This can lead to small airway obstruction, air trapping, and incr'd airway resistance.

Clinically presents with…

• Rhinitis• Tachypnea• Wheezing• Cough• Crackles• Use of accessory muscles – Intercostal or subcostal retractions

• nasal flaring

Epidemiology

• In the Northern Hemisphere, RSV infections usually occur from November through April, except in parts of Florida, where the infection season begins as early as July 1.

• The highest incidence between December and March.

• Based on population estimates, 2.1 million children younger than five years will require medical attention annually for an RSV infection.

Recurrence

• An RSV infection can occur and recur at any age.

• By two years of age, most children will have had an initial RSV infection.

• RSV infection leads to >90,000 hospitalizations annually.

• Previous infection does not protect children against reinfection

Recurrence

• Most children with an RSV infection recover uneventfully and do not have further wheezing episodes.

• However, up to 40% of children with bronchiolitis will develop further wheezing episodes through five years of age, and 10% will have wheezing episodes beyond this age.

GUIDELINES AND RECOMMENDATIONS ON DIAGNOSIS AND MANAGEMENT OF BRONCHIOLITIS

The following are from the AAP Subcommittee on the Diagnosis and Management of Bronchiolitis. They are developed recommendations endorsed by AAFP, ACCP, AAP, and ATS

Recommendation 1: assessing and diagnosing bronchiolitis

1A: Clinicians should diagnose bronchiolitis and assess disease severity on the basis of history and physical exam. Clinicians should NOT routinely order labs and radiologic studies for diagnosis (Recommendation: evidence level B).


• Important issues to assess include the impact of respiratory symptoms on feeding and hydration and the response, if any, to therapy. The ability of the family to care for the child and return for further care should be assessed. History of underlying conditions should be identified.

• Bronchiolitis' course is dynamic and variable. It may range in presentation from transient events of apnea or mucus plugging to progressive respiratory distress from lower airway obstruction.


Physical exam findings of importance include:• Respiratory rate, • increased work of breathing (evidenced by accessory muscle use

or retractions), • ausculatory findings such as wheezes, crackles, or coarse breath

sounds. RR changes considerably over the first year of life decreasing from a mean of 50 breaths per min in a term infant to approx. 40 breaths per min at 6 months and 30 breaths at 12 months. • Counting the RR for a full minute (and not extrapolating from 15s

or 30s) increases accuracy. The absence of tachypnea correlates with the lack of LRTI's or pneumonia (viral or bacterial) in infants.


• Children with bronchiolitis often have abnormal results on chest radiography, with hyperinflation, atelectasis, and infiltrates.

• However, these findings on CXR and CBC do not correlate with disease severity and should not be used to guide treatment. Therefore, chest radiography and laboratory tests are not routinely recommended.


1B: Clinicians should assess risk factors for severe disease such as age less than 12 weeks, a h/o prematurity, underlying cardiopulmonary disease, or immunodeficiency when making decisions about evaluation and management of children w/ bronchiolitis (Recommendation: evidence level B).


• Signs and symptoms associated with “Severe disease” include…– Poor feeding– Respiratory distress characterized by • Tachypnea• Nasal flaring• Grunting• Hypoxemia (or desaturations)• Intercostal retractions reflecting the increased effort to

breathe.


Underlying conditions at risk of Severe disease:• Chronic lung disease (e.g. bronchopulmonary dysplasia)• Current weight < 11 lb. (5 kg)• Cyanotic congenital heart disease• Immune compromise (e.g., severe combined

immunodeficiency)• In utero exposure to tobacco smoke• Low socioeconomic status• Neuromuscular disease• Premature birth (before 35 weeks of gestation)

Recommendation 2: Bronchodilators

2A: Bronchodilators should not be used routinely in the management of bronchiolitis (Recommendation: evidence level B).

2B: A carefully monitored trial of alpha-adrenergic or beta adrenergic medication is an option. Inhaled bronchodilators should be continued only if there is a documented positive clinical response to the trial using an objective means of evaluation (Option: Evidence level B).


• In several studies of comparison between racemic epinephrine and albuterol, racemic epinephrine has demonstrated slightly better clinical effect than albuterol.

• This is likely caused by the alpha-adrenergic–mediated vasoconstriction that may aid in decreasing nasal congestion.

• Generally, vaporized epinephrine treatments are administered only in the hospital setting because there are limited data regarding safety with unmonitored administration.


• Cochrane report concluded that there is insufficient evidence to support the use of epinephrine for the treatment of bronchiolitis among inpatients.


• In contrast to RCTs, clinical experience suggests that in selected infants, there is an improvement in symptoms after bronchodilator administration.

• It may be reasonable to administer a nebulized bronchodilator trial and evaluate clinical response; assessing the patient and documenting pre-therapy and post-therapy changes using an objective means of evaluation.

• In the event that there is documented clinical improvement, there is justification for continuing the nebulized bronchodilator treatments. In absence of it, it should not be continued.


• Anticholinergic agents such as ipratropium have not been shown to alter the course of viral bronchiolitis and at this point there is no justification for using them either alone or in combination w/ beta-adrenergics.

Recommendation 3: Steroid use.

3: Corticosteroid medications should not be used routinely in the management of bronchiolitis. (Recommendation: Evidence level B.)

• Reports indicate that up to 60% of infants admitted to the hospital for bronchiolitis receive corticosteroid therapy. Systematic review and meta-analyses of RCTs involving close to 1200 children w/ viral bronchiolitis have not shown sufficient evidence to support the use of steroids in this illness.

Recommendation 4: Ribavirin use.

4: Ribavirin should not be used routinely in children with bronchiolitis (Recommendation: Evidence level B)

• A recent review of 11 RCTs of ribavirin therapy for RSV LRTIs, including bronchiolitis, summarized the reported outcomes. Each of the 11 studies included a small sample size, ranging from 26 to 53 patients and cumulatively totaling 375 subjects. Study designs and outcomes measured were varied and inconsistent. The equality in results among the studies was highly variable.

Recommendation 4: Ribavirin use.

• Specific antiviral therapy for RSV bronchiolitis remains controversial because of the marginal benefit, if any, for most patients. In addition cumbersome delivery requirements, potential health risks for caregivers, and its high cost.

• It may be of some benefit in highly selected situations involving documented RSV bronchiolitis w/ severe disease or in high risk patients.

Recommendation 5: Antibiotic use

5: Antibacterial medications should be used only in children with bronchiolitis who have specific indications of the coexistence of a bacterial infection. When present, bacterial infection should be treated in the same manner as in the absence of bronchiolitis (Recommendation: evidence level B).

Recommendation 5: Antibiotic use

• Early RCTs showed no benefit from antibacterial treatment of bronchiolitis. However, concern remains regarding the possibility (and potential incr'd risk) of bacterial infections in young infants with bronchiolitis; thus, antibacterial agents continue to be used.

• One large study of febrile infants of <60 days old w/ bronchiolitis and/or positive RSV infection showed that overall risk of a SBI, although significant, was no different compared to those who were RSV negative.

Recommendation 5: Antibiotic use• Several retrospective studies identified low rates of SBI (0%-

3.7%) in patients w/ bronchiolitis and/or infections w/ RSV. When SBI was present, it was more likely to be a UTI than bacteremia or meningitis. In a study of 2396 infants w/ RSV bronchiolitis, 69% of the 39 patients with SBI had a UTI.

• Although AOM in bronchiolitic infants may be caused by RSV alone, there are no clinical features that permit viral AOM to be differentiated form bacterial. AOM does not influence the clinical course or lab findings of bronchiolitis and when found, it should be managed according to AAP/AAFP guidelines for AOM dx and management.

Recommendation 6: hydration and chest PT

6A: Clinicians should assess hydration and ability to take fluids orally (Strong recommendation: evidence level X).• When RR >60-70 breaths/min, feeding may be compromised,

particularly if nasal secretions are copious. • Infants w/ respiratory difficulty may develop symptoms of severe

disease and be at incr'd risk of aspiration of food into the lungs; a demonstration of feeding difficulty and a herald to the use of IVF.

6B: Chest physiotherapy should not be used routinely in bronchiolitis management (Recommendation: evidence level B). • A Cochrane review found 3 RCTs that evaluated chest physiotherapy in

hospitalized patients w/ bronchiolitis and found no clinical benefit from it. There is no evidence to support routine "deep" suctioning of the lower pharynx or larynx.

Recommendation 7: Oxygen use7A: Supplemental oxygen is indicated if oxyHb saturation (SpO2) falls persistently <90% in previously healthy infants. If the SpO2 does persistently fall <90%, adequate supplemental oxygen should be used to maintain SpO2 at or above 90%. Oxygen may be discontinued if SpO2 is at or above 90% and the infant is feeding well and has minimal respiratory distress (Option: evidence level D). 7B: As the child's clinical course improves, continuous oximetry measurement is not routinely necessary (Option: evidence level D). 7C: Infants w/ known hemodynamically significant heart or lung disease, as well as premature infants, require close monitoring as the oxygen is being weaned (Strong recommendation: evidence level B).

Recommendation 7: Oxygen use• Pulse oximetry has been rapidly adopted into the clinical

assessment of children with bronchiolitis on basis of data suggesting that it can be reliably detect hypoxemia unsuspected on exam.

• Among inpatients, perceived need for supplemental oxygen that is based on pulse oximetry has been a/w higher risk of prolonged hospitalizations, ICU admission, and mechanical ventilation.

• Among outpatients, available evidence differs on whether mild reductions in pulse ox predict progression of disease or need for return visit for care.

Recommendation 7: Oxygen use

• Scheduled spot checks with pulse oximetry are adequate for patients with bronchiolitis.

• Continuous pulse oximetry monitoring is not routinely necessary and should be reserved for children who previously required continuous oxygen, had apnea, or have an underlying cardiopulmonary condition.

Recommendation 7: Oxygen use

• Before instituting oxygen supplementation, the accuracy of the initial reading should be verified by repositioning the probe and repeating the measurement.

• Nasal and oral airway should be suctioned first.

• If SpO2 remains <90% in face of such initial management, oxygen should be administered.

Recommendation 8: RSV ppx use

8A: Palivizumab ppx may be considered in selected infants and children w/ any relevant history of: CLD, prematurity (<35 wks GA), or CHD (Recommendation: evidence level A). – Any infant w/ incr’d risk of severe disease.

8B: Palivizumab administration involves 5 monthly doses, usually starting in Nov. to Dec. at a dose of 15mg/kg/dose IM (Recommendation: evidence level C).

Recommendation 9: Hand decontamination

• 9A: Hand decontamination is the most important step in preventing nosocomial spread of RSV. Hands should be decontaminated before and after direct contact w/ patients, after contact w/ fomites in direct vicinity of patient, and after removing gloves (Strong rec: evid level B).

• 9B: Alcohol-based rubs are preferred for hand decontamination. Hand washing is another alternative w/ antimicrobial soap (Rec: Evid level B)

• 9C: Education of hand sanitization and the rationale to personnel and family members is a responsibility of the clinician (Rec: evid level C).

Recommendation 10: Smoking & Breastfeeding

10A: Infants should not be exposed to passive smoking (strong rec: evid level B).

10B: Breast feeding is recommended to decrease a child's risk of having lower respiratory tract disease (rec: evid level C).

Recommendation 11: Alternative therapies

11: Clinicians should inquire about use of CAM (option: evid level D).

• Various forms of non-conventional treatment: homeopathy, herbal remedies, osteopathic manipulation, and applied kniesiology. Whether these tx's would prevent development of bronchiolitis is unknown.

• To date, there are no studies that conclusively show a beneficial effect of alternative therapies used for the treatment of bronchiolitis.

Management, in summation:

• Goals in management:– SUPPORTIVE/SYMPTOMATIC CARE– HYDRATION– OXYGENATION

Management, in summation:

• An RSV infection is self-limited and responds to supportive care:– Bed-side humidification– Nasal saline drops– Nasal suction (non-routine, occasional deep

suction with severe mucus plugging of nasal passages)

– Hyper saline nebulizer, when necessary.

viral bronchiolitis - cb

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