Respirology Flashcards
What is the diagnostic criteria for BRUE?
BRUE: a sudden, brief, and now resolved episode in a child <1 year of age, including ≥ 1 of the following:
1. Cyanosis or pallor 2. Absent, decreased, or irregular breathing 3. Marked change in tone (hyper- or hypotonia) 4. Altered level of responsiveness
Which areas of the lung are the “dependent areas” of the lung?
- R and LUL
- Apical segment of the RLL
What antibiotics should be used in empiric treatment of lung abscess?
• 2-3 wks IV antibiotics for uncomplicated cases
• Follow with 4-6 wks of PO antibiotics
• Guide Abx choice with Gram stain results
• Empiric treatment: Penicillinase-resistant agent + aerobic coverage
i.e. Cloxacillin + Clindamycin/Clavulanic acid)
What is the definition for ARDS (Berlin definition)?
- Acute onset (<7 days)
- Severe hypoxemia (PaO2/FiO2 <300 for acute lung injury, or <200 for ARDS)
- Diffuse bilateral pulmonary infiltrates consistent with pulmonary edema (can be patchy and asymmetric, and pleural effusions can be present)
- Absence of L atrial hypertension (pulmonary artery wedge pressure <18 mm Hg if measured)
In what situations is pulse oximetry unreliable?
- In highly deoxygenated states
- In the presence of carboxyhemoglobin (overestimates as in cases of carbon monoxide poisoning)
- In the presence of methemoglobin (over-/underestimates)
What are the diagnostic criteria to confirm asthma?
- Change in 12% in FEV1 following use of bronchodilator
- Positive methacholine challenge (PC20 < 4 mg/mL) or exercise stress test (> 10-15% decrease in FEV1 post-exercise)
- FEV1/FVC ratio <0.8 of predicted
- Increase of at least 20% in peak expiratory flow after use of bronchodilator
What are the Canadian Thoracic Association’s guidelines for GOOD control of asthma symtoms?
- Daytime symptoms <4 days/wk
- Night time symptoms <1 night/wk
- Physical activity - normal
- Exacerbations - mild/infrequent
- No absences from work or school due to asthma
- Need for a fast-acting beta2 agonist <4 doses/week
- FEV1 or PEF ≥90% personal best
- Sputum eosinophils < 2-3%
What are common allergenic triggers for children with asthma?
- Indoor: Animal dander, dust mite, cockroach, molds
- Seasonal aeroallergens: Pollens (trees, grass, weeds), seasonal molds
- Air pollutants: Environmental tobacco smoke, ozone, N2O2, sulfur dioxide, particulate matter, wood/coal burning smoke, mycotoxins, endotoxins, dust
- Strong/noxious odours/fumes: Perfumes, hairspray, cleaning agents
- Occupational: Farm/barn exposures, formaldehydes, cedar, pain fumes, cold dry air, exercise, crying/laughter/hypeventilation
What side effects of chronic inhaled steroid use should be discussed with families?
• Most common:
- oral candidiasis (thrush) –> propellant induced mucosal irritation and local immunosuppresion
- dysphonia (hoarse voice) –> vocal cord myopathy
• Long-term, prospective NIH-sponsored CAMP study - slight height reduction of 1 cm in final adult height
What is generally a medium dose of ICS?
200-400 mcg/day
How does the treatment algorithm for asthma change based on age?
- In children > 12 yoa, start with SABA, add low dose ICS and then consider LABA first before either medium dose ICS or leukotriene receptor inhibitor, then steroids or anti-IgE
- In children 6-12 yoa, start with SABA, add low dose ICS then move to medium dose ICS before considering either LABA or leukotriene receptor inhibitor, then steroids or anti-IgE
What is the criteria for diagnosing asthma in a preschooler?
- Documented or reliable history of wheeze or obstructive airflow by health care provider (or parent)
- Documented response to inhaled SABA or oral steroids
- Does not meet criteria for any other illness
What considerations should be made for asthmatic children preparing for elective surgery?
- Asthma should be well controlled prior to surgery
* Caution should be used when using volatile inhalants for induction, particularly desflurane
What are some potential complications with chest tubes?
- Injury on insertion (diaphragm, nerves, blood vessels)
- Pneumothorax
- Dislodgement
- Malposition
- Occlusion
- Pain
- Pulmonary re-expansion pulmonary edema
Causes of chylothorax
• Post cardiothoracic surgery
- Chest injury, ECMO
• Primary or metastatic intrathoracic malignancy (i.e. Lymphoma)
• Thoracic duct rupture during delivery
• Lymphangiomatosis
• Thrombosis of the duct, SVC or subclavian vein
• Infection: TB, histoplasmosis
• Congenital anomalies of the lymphatic system
- Missense mutation in integrin aα9 gene
• Trauma/Child abuse
• Idiopathic
How to manage a child with chylothorax?
- Enteral feedings with a low fat or MCT, high-protein diet or TPN
- Thoracentesis (repeated)
- Pleuroperitoneal shunt, thoracic duct ligation or application of fibrin glue
- Parenteral octreotide (0.5 - 1 µg/kg/hr to a maximum of 10 µg/kg/day) can be used
- PPV with PEEP
What condition is associated with PHOX2B mutations?
Congenital central hypoventilation syndrome
may also see a subset with Hirshsprung’s Disease
What clinical manifestations are seen in cases of OSA?
- Sleep related: Loud, frequent and disruptive snoring, Breathing pauses, Choking or gasping arousals, Restless sleep, More frequent partial arousal parasomnias (i.e. Sleepwalking and sleep terrors), Hyperextension of neck to maintain airway patency
- Daytime: Mouth breathing, Dry mouth, Chronic nasal congestion/rhinorrhea, Hyponasal speech, Morning headaches, Difficulty swallowing, Poor appetite, Secondary enuresis, Daytime sleepiness with drowsiness, Increased irritability, mood instability and emotional dysregulation, Low frustration tolerance, Anxiety/depression, Aggression, impulsivity, hyperactivity, oppositional behaviour, conduct problems
What is the gold standard test for OSA?
Polysomnogram
What does the CPS recommend with respect to empiric treatment of pneumonia?
- If uncomplicated, first line is amoxicillin
- If requires hospitalization, ampicillin (IV)
- If hospitalized and in resp distress, 3rd generation cephalosporin such as ceftriaxone
- May add vancomycin if there is concern for MRSA
Standard treatment duration in Canada is 7-10 days (5 days if as outpatient)
What are the most common pathogens in the case of pneumonia (immunocompetent host)?
- Strep pneumo
- S. aureus
- Strep pyogenes (GAS)
- MRSA
What does the CPS recommend in the case of complicated pneumonia?
Cefotaxime/ceftriaxone +/- clindamycin (anaerobic infections/CA MRSA) OR vancomycin (MRSA)
No consensus on duration, typically 3-4 weeks
What are the most common causes of pleurisy (inflammation of pleura)?
Bacterial pneumonia!!!
• Next most common causes:
○ Heart failure
○ Rheumatologic causes
○ Metastatic intrathoracic malignancy
What is the genetic inheritance pattern of Kartagener Syndrome?
Heterogeneous group of disorders; generally AR but there are AD, X-linked conditions
