Board ReviewYou take my breath away:

Jillian Parekh, MD

February 2, 2010

Asthma – random facts

Mortality of asthma is on the rise Until puberty it is more common in males MDIs (if used properly) are as effective as

nebulizers In mild asthma, 60% will outgrow In severe asthma, 30% will outgrow No evidence for Levalbuterol over Albuterol 80% asthmatics have immediate type allergy

skin tests

An 11 y/o F p/w 6 mos of coughing, wheezing and chest tightness. Usually has these sx 3 times/week during the day, but also wakes up at night once a month with the same sx. Sx have improved when she has used her mom’s beta-2-agonist. Her parents are worried b/c she sometimes has to miss school b/c of her sx.

BASED ON FREQUENCY OF SX, BEST CATEGORIZATION OF HER ASTHMA IS:A. Exercise induced asthmaB. Mild intermittent asthmaC. Mild Persistent asthmaD. Moderate persistent asthmaE. Severe persistent asthma

Answer:

A. Exercise induced asthma

B. Mild intermittent asthma

C. Mild Persistent asthma

D. Moderate persistent asthma

E. Severe persistent asthma

Classification Intermittent:

• Symptoms < 2 x / week

• Night time symptoms < 2 x / month

• Albuterol < 2 x / week

• No interference with normal activity

• (Lung function > 85%)

Only class you treat with bronchodilators alone

Mild Persistent

• General symptoms > 2 x / week

• Night time symptoms > 2 x / month

• Albuterol use > 2 x / week

• Minor limitation in activity

• (Lung function >80%)

Low dose ICS ORLeukotriene inhibitor

Moderate Persistent:• Daily symptoms

• Night time symptoms > 1 x / week, but not daily

• Albuterol daily

• Some limitation in activity

• (Lung function 75-80%)

Low dose ICS + LABA / Leukotriene inhibitor

Medium dose ICS

Severe Persistent:• general symptoms throughout the day

• night symptoms every night

• Albuterol several times/day

• Extreme limitation in activity

• (Lung function <75%)

Medium dose ICS + LABA / Leukotriene

Exacerbations Mild: decrease in pulmonary fxn, but > than

50% predicted• Manage with Albuterol • Don’t fall for trap to order abx for asthmatic w/ fever

and cough (viral, viral, viral, viral)!

Moderate and Severe: PFT < than 50% of predicted

No role for mucolytics and chest PT as part of routine care for asthma exacerbations

Exercise Induced Asthma

Coughing and wheezing 5 mins after exercising with gradual improvement within 15 mins of rest

Cold, dry air is the worst Results from poor control and management

• Encourage exercise Other causes of poor exercise tolerance

• Cardiac• anemia• Muscle weakness• Poor conditioning

Prognosis

Risk factors for persistent asthma:

• Onset before age 3

• IgE elevation

• FMH asthma

• Peripheral Eosinophilia

A 14 y/o M presents to the ED with a severe asthma exacerbation and resp failure. Despite intubation and aggressive resuscitation, he develops severe acidosis, pulmonary edema and hypoxic encephalopathy. His condition worsens over the next week and the parents decide to withdraw care.

OF THE FOLLOWING, THE RISK FACTOR MOST ASSOCIATED WITH FATAL ASTHMA IS:

A.Caucasian RaceB.High SESC.Poor perception of symptomsD.Sensitivity to house dust mitesE.Use of daily low-dose inhaled corticosteroids.

Answer:

A. Caucasian Race

B. High SES

C.Poor perception of symptoms

D.Sensitivity to house dust mites

E. Use of daily low-dose inhaled corticosteroids

Explanation: Risk Factors for Asthma Deaths:

• H/o sudden severe exacerbations• Prior intubation • Prior PICU admit• 2+ asthma admits in last year• 3+ ED visits in past year• ED or admission in past month• Use of > 2 canisters Albuterol/month• Current use of systemic steroids or recent withdrawal• Difficulty perceiving airflow obstruction and its severity• Co-morbidities that affect cardiopulm systems• Serious psych disease or psychosocial problems• Low SES and urban residence• Illicit drug use

A 2 y/o M is brought to ED with moderate resp distress. He is an ex 25 weeker with h/o BPD. +rhinorrhea and cough x 2 days, this morning he developed rtx and wheezing that was unresponsive to Albuterol. Usual meds are Albuterol and oxygen at 1L/min to keep O2 sat > 93%. HR: 160, RR: 60, O2: 82%. You place him on 100% O2 via non-rebreather mask, and get an ABG: 7.35, PCO2:70, O2: 225, HCO3:35. The nurse then calls you because patient is apneic.

OF THE FOLLOWING THE MOST LIKELY EXPLANATION FOR HIS SUDDEN DETORIORATION IS:

A.Acute pulmonary embolus with increased AA gradientB.Elimination of respiratory drive by correction of chronic

hypoxemiaC.Respiratory muscle fatigue due to acute metabolic acidosisD.Severe bronchospasm with acute respiratory acidosisE.Spontaneous pneumothorax with acute hypoxemia

Answer:

A. Acute pulmonary embolus with increased AA gradient

B.Elimination of respiratory drive by correction of chronic hypoxemia

C.Respiratory muscle fatigue due to acute metabolic acidosis

D.Severe bronchospasm with acute respiratory acidosis

E. Spontaneous pneumothorax with acute hypoxemia

Explanation:

RESPIRATORY DRIVE of many CRF patients is dependent on hypoxemia and correction of hypoxia can lead to respiratory arrest

ABG in chronic resp failure includes a near normal pH, increased PC02, decreased P02 and elevated serum bicarb. Can also have polycythemia and pulm HTN with RVH due to chronic hypoxemia.

CRF patients can benefit from O2 to maintain sats between 90-95% as to limit the consequences of chronic hypoxemia or to treat acute decompensations.

Hypercapnia

Low PCO2 with acute asthma: Tachypnea

High PCO2C02 retention and fatigue = BAD

Signs of hypercapnia: flushing, mental status change, headache, tachycardia

Other causes of wheezing

Aspiration BPD / CLD Foreign body Aspiration Vascular rings/anatomic anomalies Bronchiolitis

You are seeing a 2 m/o M who has Trisomy 21 for WCC. The boy’s mother expresses concern that the infant has been having “noisy breathing” x 2-3 weeks. No feeding difficulties and is exclusively breast fed. According to mom, the noise, which occurs on inspiration, is louder when the infant is supine and crying. He was born via NSVD, no forceps, Apgars of 8, 9. His vitals are appropriate for age, but you hear an audible noise during inspiration.

OF THE FOLLOWING, THE MOST LIKELY EXPLANATION FOR THE INFANT’S RESP SX IS:A.LaryngomalaciaB.Subglottic tracheal webC.TracheomalaciaD.Vascular RingE.Vocal Cord paralysis

Answer:

A.Laryngomalacia

B. Subglottic tracheal web

C.Tracheomalacia

D.Vascular Ring

E. Vocal Cord paralysis

Explanation: Disorders at level of and above the vocal cords result in a harsh,

inspiratory noise– STRIDOR. Lesions inferior to the vocal cords usually result in wheezing – high

pitched expiratory sound. Laryngomalacia is most common congenital laryngeal abnormality

causing stridor. Usually are symptomatic at 1-2 months. Stridor worsens in supine position and with crying or URI. Usually improves by 2 y/o (severe cases may require surgical correction).

Tracheomalacia presents with wheezing. Laryngeal web usually presents with stridor at birth (failure of

embryonal airway to recanalize). Vascular ring p/w recurrent wheezing. Vocal cord paralysis p/w stridor, but also usually associated with

weak cry, feeding problems (coughing and choking).

A 2 y/o F has a choking episode in the waiting room of your office while eating peanuts. When you evaluate her she appears well, coughing has resolved, her RR is 24 and her 02 sat is 97%. Her lung exam reveals coarse rhonchi at both lung bases with an end expiratory wheeze in the RML. AP, lateral and decub Xrays appear normal.

OF THE FOLLOWING, THE NEXT MOST APPROPRIATE STEP IN THE EVAL OF THIS PATIENT IS:

A. CT of the chestB. Flexible laryngoscopyC. Fluoroscopy of the chestD. No further evaluationE. Rigid bronchoscopy

Answer:

A. CT of the chest

B. Flexible laryngoscopy

C.Fluoroscopy of the chest

D.No further evaluation

E. Rigid bronchoscopy

Explanation: Whenever FB is certain or high index of suspicion – rigid

bronchoscopy should be performed emergently. Serves as diagnosis and treatment.

Toy balloons (gloves) are the objects most commonly involved in fatal childhood FB aspiration.

Most FBs are radiolucent, but initial evaluation should be Xrays. Can show signs of air trapping (unilateral hyperinflation, atelactasis, or mediastinal shift). Will be normal in 27-65%.

Flexible laryngoscopy is not useful b/c a bronchial FB can’t be seen.

Foreign Body Infants/Toddlers/MR

• Infants usually aspirate food• Toddlers usually “objects”

Manifest within 24 hours usually – sudden onset

TRIAD:• Cough (unlabored breathing w/ intermittent non

productive cough)• Wheeze (localized and fixed)• Decreased BS

A 2 year old M is brought to your office bc of night time cough. According to mom, several times over the past few months he has awakened with a barking, nonproductive cough that improves by the next morning. She denies fever and rhinorrhea with the episodes. Lungs are normal on exam.

OF THE FOLLOWING, THE CLNINCAL FEATURE THAT IS MOST SUGGESTIVE OF SPASMODIC CROUP RATHER THAN RECURRENT LARYNGOTRACHEOBRONCHITIS IN THIS BOY IS:

A.Age of the patientB.Barking nature of the coughC.Lack of rhinorrhea and feverD.Nonproductive nature of the coughE.Normal findings on PE

Answer:

A. Age of the patient

B. Barking nature of the cough

C.Lack of rhinorrhea and fever

D.Nonproductive nature of the cough

E. Normal findings on PE

Explanation:

Croup is the most common cause of acute upper airway obstruction in children.

Spasmodic croup is similar to acute croup in that the cough is often “barking” and nonproductive. Allergic and psychological factors are believed to be primarily responsible for spasmodic croup. Classically, not associated with infectious sx.

Croup

Most common bugs are:• RSV

• Influenza

• Parainfluenza

Will describe inspiratory stridor or a biphasic stridor.

You are working with a medical student in clinic. His first case is a 4 m/o M who has had 4 days of rhinorrhea, coughing, and tachypnea. On PE: infant is fussy, T: 99.2, HR: 110, RR: 60, 92% on RA. On auscultation, expiratory wheezes are audible in all lung fields. You discuss the DDx and ask the med student what he knows about RSV.

OF THE FOLLOWING, THE MOST ACCURATE STATEMENT REGARDING RSV IS :

A.Household pets can be colonized with RSV and may act as reservoirs for transmission to family members.

B.Most chest X-rays of infants hospitalized for RSV bronchiolitis appear normal.

C.Most infants who develop RSV bronchiolitis require admission.D.Recurrent wheezing may occur for several years after mild or

severe RSV bronchiolitis.E.The initial RSV infection usually occurs in school-age children

Answer:

A. Household pets can be colonized with RSV and may act as reservoirs for transmission to family members.

B. Most chest Xrays of infants hospitalized for RSV bronchiolitis appear normal.

C. Most infants who develop RSV bronchiolitis require admission.

D. Recurrent wheezing may occur for several years after mild or severe RSV bronchiolitis.

E. The initial RSV infection usually occurs in school-age children

Explanation:

RSV is the most common pathogen causing lower airway disease in infants and toddlers.

Recurrent wheezing after RSV may occur for months to years in 33%-50% of affected children. Males are at higher risk for recurrent wheezing, or later diagnosis of asthma.

Transmission is via human-human contact. Chest Xrays are normal in ~10% (peribronchial thickening or

interstitial pneumonia) Most infants can be treated as outpatients. Initial infection is almost universal by age 2, so primary infection in

school-aged children is rare.

Bronchiolitis Usually between age 2-7 mos (but up to 2 y/o) Obstruction of the small airways secondary to virus, often RSV

(paromyxovirus is 2nd leading cause) 50% of infants with severe RSV will develop recurrent

wheezing CXR findings are non focal: hyperinflation and patchy infiltrates Prevention of spread: HAND WASHING (not wearing a mask) Treatment is symptomatic

• Albuterol or prednisone as warranted Admission criteria:

• Reliability of parents• Duration of sx• Underlying medical conditions• Less than 3 mos, low 02 sats, poor feeding, dehydration

Chronic Cough

Initial screen:• Routine CXR

• PPD

• Sweat test

Cough suppressants in children have no benefit over placebo

Psychogenic cough: loud, brassy barking/honking. Can be produced on command. Disappears during sleep.

During the health supervision visit of a 2 y/o M who is new to your clinic, you note a productive cough that his mother says has been present for several months. His weight is below the 5%. Fine crackles are present in his lungs b/l, he has mild clubbing of the fingers. The remainder of his exam is unremarkable. CXR reveals poorly defined bronchovascular markings and a few cystic spaces b/l. You then order a chest CT, which reveals diffuse bronchiectasis.

OF THE FOLLOWING THE MOST LIKELY DIAGNOSIS IS:

A.Allergic bronchopulmonary aspergillosisB.Cystic FibrosisC.Foreign body aspirationD.Mycobacterium tuberculosis infectionE.Primary ciliary dyskinesia

Answer:

A. Allergic bronchopulmonary aspergillosis

B.Cystic Fibrosis

C.Foreign body aspiration

D.Mycobacterium tuberculosis infection

E. Primary ciliary dyskinesia

Explanation:

The most common cause of bronchiectasis in children is cystic fibrosis.

Bronchiectasis is characterized by abnormal dilatation of the bronchi and bronchioles.

In CF, recurrent infections and inflammation cause chronic obstruction and hypertrophy of the wall of the bronchi.

Changes in the bronchial tree are irreversible.

Cystic Fibrosis Sweat test is gold standard: 60 mEq or greater is

diagnostic Often see low albumin/sodium, FTT and

pseudomonas infxn AR genetics (carriers show no signs) Treat flares with Aminoglycoside + Piperacillin

(pseudomonas)• Staph infxn early in life

• Pseudomonas later in life Carrier rate is 1/25 (know this)

• Like to ask “what are the odds”…Go to p. 411.

CF in infancy

In infants: GI sx > Resp sx• Vit E defcy hemolytic anemia

• Vit K defcy prolonged prothrombin time

Anemia Hypoproteinemia Steatorrhea Recurrent pulmonary sx

Tuberculosis Most children will be asymptomatic + PPD, - CXR = LTBI

• INH x 9 months• Rifampin x 9 months (if resistant)

+ PPD, + CXR = Active disease• Most common CXR finding: hilar adenopathy2 months of RIP THEN

• 4 months of INH + RifampinOR9 months of INH + Rifampin

Extrapulmonary TB:• Meningitis – treat with RIP + streptomycin x 2 mos, then 10 mos

of RI, steroids used too.• Adenitis• Pleuritis• Disseminated (Miliary Disease)

ALTE A =

• APPARENT Ceases to breathe Cyanosis or pallor Becomes unresponsive Ressucitated successfully Admit for observation (based on hx, physical will be normal) Remember NALS

• Neuro

• Abuse/Trauma

• Lung (infxn, aspiration, apnea, GER)

• Sugar (hypoglycemia, metabolic)

SIDS Risk factors:

• Sleeping on tummy• Co-sleeping• Low SES• Smoking• Cold Weather (bundling?)• Young parents

• Risk for SIDS peaks at 2-3 mos, decreases after 6 months.

An infant who was born at 26 weeks gestation, weighing 700 grams, is nearing 37 weeks corrected age. He is receiving nasal cannula oxygen (0.2 L /min) and being treated with diuretics for CLD. He has no intracranial hemorrhage and is growing well on enteral feedings via a NG tube. Attempts at oral feeding have been unsuccessful because of frequent oxygen desaturation, bradycardia, and concerns over the inability to coordinate sucking-swallowing. The mother asks why you are continuing to feed her son via a feeding tube.

OF THE FOLLOWING, THE CONDITION THAT BEST EXPLAINS WHY HER SON HAS A FEEDING PROBLEM IS:

A.Apnea of prematurityB.Chronic Lung DiseaseC.Gastroesophageal refluxD.Necrotizing enterocolitisE.Tracheoesophageal fistula

Answer:

A. Apnea of prematurity

B.Chronic Lung Disease

C.Gastroesophageal reflux

D.Necrotizing enterocolitis

E. Tracheoesophageal fistula

Explanation:

Infant described has problems coordinating breathing with sucking and swallowing.

No apnea of prematurity described. GER usually occurs after a feeding, not

during it. NEC would show more decompensation with

acute abdomen. TEF is associated with resp distress and

secretion control problems in between feeds.

Neonatal Pulmonary

Central Apnea• No respiratory effort bc no signal from CNS

Obstructive Apnea• Upper airway occlusion stops airflow

Periodic Breathing• < 20 seconds, no associated brady or cyanosis

Remember association b/w anemia and apnea of prematurity

A 4 y/o child who was struck by a car is unconscious and has a shallow respiratory rate of 6 breaths/min on arrival at the ED. You begin BVM ventilation and prepare to intubate the child. The respiratory therapist asks you what size ET tube you would like.

OF THE FOLLOWING, THE CORRECT ET TUBE IS:

A. 4.5 mm cuffedB. 5.0 mm cuffedC. 5.5 mm cuffedD. 5.0 mm uncuffedE. 5.5 mm uncuffed

Answer:

A. 4.5 mm cuffed

B. 5.0 mm cuffed

C.5.5 mm cuffed

D.5.0 mm uncuffed

E. 5.5 mm uncuffed

Explanation: Estimate of ETT size:

• Diameter of child’s 5th finger Age/4 + 4 = uncuffed size Age/4 + 3 = cuffed size Usually should prepare ETTs one size larger and one

size smaller, as above are only estimations. Cuffed tubes tend not to be used b/c of concern for high

cuff pressure causing ischemic tracheal necrosis. For inpatients with monitored use – cuffed tubes are safe

and sometimes necessary to prevent air leak.

You are admitting a 35-week gestation newborn to the NICU for respiratory distress at 4 hours of age. She requires assisted ventilation. The resident working with you asks what test of pulmonary function is preferred in your initial assessment of this newborn.

OF THE FOLLOWING, THE BEST RESPONSE IS:

A. Aterial blood gas testingB. Capillary blood gas testingC. End- tidal carbon dioxide monitoringD. Pulse oximetery monitoringE. Transcutaneous PaO2 monitoring

Answer:

A.Arterial blood gas testing

B. Capillary blood gas testing

C.End- tidal carbon dioxide monitoring

D.Pulse oximetery monitoring

E. Transcutaneous PaO2 monitoring

Explanation: Preferred method for assessing overall pulmonary function is

arterial blood gas testing. Capillary blood gas is least reliable b/c of inadequacy of tissue

perfusion at heel (can warm heel first), circulatory volume, vasoconstriction due to shock or hypothermia. Only approximates Pa02.

Pulse ox measures arterial hemoglobin saturation via infrared light-emitting diode technology. Can be affected by temperature, acid-base balance, fetal hemoglobin.

End tidal PCO2 – need to be intubated. Best used to follow trends of CO2.

Transcutaneous PaO2 is limited and dated technology. Requires correlation with ABG. Measures capillary blood oxygen with silver electrode across skin.

Respiratory Failure

Tachypnea is the earliest sign Assessing respiratory effort is always

first thing to do. Do not get ABG first.

Chronic hypoxemia:• Kidneys produce more erythropoietin, more

RBCs are made, results in increased HCT.

Pleural Fluid

Chylothorax: electrolyte concentrations are similar to serum. High TG (> 110) and protein (>3). Usually post-op from cardiac surgery.

Transudate: remember this as “transitional” – the problem lies somewhere else• Cirrhosis, nephrotic syndrome, CHF

Assessing oxygenation Carboxyhemoglobin is elevated in C0

poisining. Pulse ox will overestimate level of oxyhemoglobin.

Methemoglobin will give unreliable pulse ox – non cardiac cause of cyanosis. Blood will be “chocolate colored”

Impaired peripheral perfusion (shock) pulse ox is unreliable

ABG is best measure of pulmonary function in a newborn