Respiratory Flashcards
Investigation of acute bronchiolitis***
> Blood
- FBC
- Pulse oximetry, ABG
> Imaging
- CXR: hyperinflation, segmental collapse
- Diagnosis mainly based upon history and PE
Complication of acute bronchiolitis***
- Recurrent apnea
- Asthma
- Bronchiolitis obliterans (Defective repair process after small airways injury -> excessive proliferation of granulation tissue that causes narrowing or obliteration of the airway lumen)
Risk factor for severe acute bronchiolitis***
- Preterm infants (who develop bronchopulmonary dysplasia)
- Low birth weight
- Age <12 weeks
- Anatomical defect of airways
- Congenital heart disease
- Neuromuscular disorders, including those who have difficulty swallowing or clearing mucus secretion
- Immunodeficiency
Management of acute bronchiolitis***
> General
- SpO2 >93%
- NG feeding for those refuse to feed; IV fluid for severe respiratory distress
> Pharmacotherapy
- 3% NS via nebulizer -> increase mucus clearance
- Inhaled B2-agonist + O2
- Antibiotics: for recurrent apnea, acute clinical deterioration, high WCC
- Inhaled steroid X benefit
Causative organism for pneumonia in children***
- Majority LRT infection is viral in origin (eg: RSV, influenza A or B, adenovirus, parainfluenza virus
> Newborns
- Group B streptococcus
- E. coli
- Kleb. sp
- Enterobacteriaceae
> Infancy (Mostly viral)
- RSV
- Strep. pneumoniae
- H. influenzae
- Staph. aureus
> Older children (bacteria more common)
- Mycoplasma pneumoniae
- Strep. pneumoniae
Definition of bronchial asthma
- Chronic airway inflammation
- Recurrent episode of wheezing, breathlessness, chest tightness, and coughing
- Reversible airway obstruction
Cut off point to diagnosed asthma in reversibility test
- > 20% improvement in PEFR, or >12% improvement in FEV1
- In response to administration of bronchodilator
Classification of acute asthma exacerbation based on severity (Components)***
” WORST GASP”
- Wheezing
- Oxygen saturation
- Respiratory rate
- Speech
- Tachycardia/ bradycardia
- GCS
- Accessory muscle use
- SOB when…
- PEFR
Level of Asthma control (GINA 2018)
> In the past 4 weeks
- Daytime asthma symptoms >2x/ week
- Nocturnal symptoms/ night waking
- Reliever needed >2x/ week
- Activity limitation
> Level
- Well: None
- Partly: 1-2 of these
- Uncontrolled: 3-4 of these
Investigation for asthma***
- Bronchodilator reversibility test
- ABG (in severe acute asthma)
- FBC: leukocytosis (infective exacerbation), eosinophilia
- Blood C&S: if suspect infective cause
- CXR (Rarely needed, TRO pneumothorax, pneumonia, lung collapse)
How to prepare nebulized salbutamol
- <2 year old: 0.5ml salbutamol + 3.5ml NS (total 2.5mg)
- >= 2 year old: 1ml salbutamol + 3ml NS (total 5mg)
Management of acute exacerbation of asthma (at ED)***
- Secure ABC
- Continuous vital sign monitoring
- Assess and treat according to severity of exacerbation:
Mild
- Neb Salbutamol + oral Prednisolone 1mg/kg/day for 3 to 5 days
- Review after 20 min, if no improvement -> treat as moderate
- If improve -> keep and observe 60 min before discharge
Moderate
- Neb Salbutamol (+- Ipratropium) + O2 8L/min + oral Prednisolone 1mg/kg/day for 3 to 5 days
- Admission if no improvement
- If improve -> keep and observe 60 min before discharge
Severe
- Neb Salbutamol + Ipratropium + O2 8L/min + continuous IV Salbutamol
- IV Hydrocortisone: 4 x body weight (max 100mg)
- Admit to HDU or ICU for continuous monitoring
Plan if allow discharge asthma patient**
- TCA in 2 to 4 weeks
- Continue oral Prednisolone for 3 to 5 days
- MDI Salbutamol 4 to 6 hourly for few days (prophylactic)
- Emphasize on asthma action plan
Complication of asthma
- Bio: failure to thrive, exacerbation, frequent chest infections, disturbed sleep, inability to exercise
- Phycho: lower self-esteem, anxiety
- Social: under-performance, frequent absenteeism
Complication of pneumonia***
- Pleural effusion and empyema
- Necrotizing pneumonia
- Lung abscess
- Pneumatocele
- Hyponatremia
Why bronchodilators is not effective in bronchiolitis
- The pathophysiology of bronchiolitis consists of terminal bronchiolar and alveolar inflammation with airway swelling and luminal debris, which lead to airway obstruction (dilatation wont unclogged the debris)
- In addition, mediators of bronchospasm have been shown to be present in variable amounts in children with bronchiolitis. Thus, not all children with bronchiolitis are likely to have the same propensity to have bronchospasm and bronchial hyperreactivity
Type of respiratory failure***
> Type 1 (hypoxemia)
- Damage to lung tissue
- Low oxygen, normal to low CO2
- Eg: pneumonia, asthma
> Type 2 (hypercapnia)
- Alveolar ventilation is insufficient
- Low or normal oxygen, hypercapnia
- Eg: COPD, CNS depression
Septic workup
- FBC: Leukocytosis with left shift
- LFT, RP: Determine deterioration in organ function
- Bacterial culture
- CRP
- Procalcitonin levels: Acute phase reactant that is elevated in severe bacterial infection
Investigation for tuberculosis **
- Tuberculin skin test: Might be falsely positive due to prior BCG vaccination
- Interferon-gamma release assays: In-vitro blood tests of cell-mediated immune response to relatively TB-specific antigens (such antigen are absent in BCG vaccine)
Useful in evaluation in BCG-vaccinated individual - CXR: Opacification of hilar region
Difference between bronchiolitis, asthma, pneumonia
(Refer note “Acute Bronchiolitis”)
What is atypical pneumonia
- Pneumonia caused by atypical organism that are not detectable on Gram stain and cannot be cultured using standard methods
- Eg: Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella pneumophila
Drug regime for tuberculosis**
- 2 months of isoniazid, rifampicin, pyrazinamide and ethambutol, followed by 4 months of isoniazid
and rifampicin
Side effect of TB medication
- Isoniazid: peripheral neuropathy
- Rifampicin: orange discoloration of urine
- Pyrazinamide: joint pain
(all 3 cause skin rash, jaundice, hepatotoxicity, nausea, abdominal pain) - Ethambutol: impairment of color vision
Prevention for acute bronchiolitis***
- Monoclonal antibody of RSV - “Palivizumab”
§ IM injection monthly in high risk infants
§ Very expensive - -zumab is a suffix for humanized monoclonal antibody; -ximab is for chimeric anf -umab for human
§ Adalimumab
§ Alemtuzumab - No active vaccination to prevent RSV bronchiolitis yet
Difference between croup and acute epiglottitis
> Croup
- Parainfluenza virus
- Presentation: coryza symptoms, barking cough
- Ix: “steeple sign”” in CXR
> Epiglottitis
- H. influenza type b
- Presentation: highly febrile
- Ix: “thumb sign” in CXR
Complication of croup
- Dehydration
- Risk of respiratory failure
- Pulmonary edema
- Pneumothorax
- However complication uncommon
Indication of antibiotic in acute bronchiolitis
- Recurrent apnea and circulatory impairment
- Possibility of septicemia
- Acute clinical deterioration
- High white cell count
- Progressive infiltrative changes
MOA and Side effect of salbutamol
> MOA
- Activate beta 2 adrenergic receptor on airway smooth muscle -> relaxation
> Side effect
- Tremor
- Chest pain
- Palpitation, tachycardia
Clinical feature of foreign body aspiration
- Clinical feature: wheeze, cough, diminished breath sound
- Laryngotracheal: stridor, wheeze, salivation, dyspnea, voice changes
- Large bronchi: cough, wheeze
- Lower airway: little acute distress after initial choking episode
URTI vs LRTI
> LRTI - Airways below the larynx - Cough as primary symptoms - Eg: bronchitis, pneumonia, tuberculosis > URTI - Structures in the larynx or above - Sneezing, headache, and sore throats - Eg: common colds, sinus infection, tonsillitis, laryngitis
- Croup is both URTI and LRTI as it is laryngotracheobronchitis
Evaluation of the background of newly diagnosed asthma (Intermittent or Persistent) ***
> Intermittent
- Daytime symptoms: <1x/week
- Nocturnal symptoms: <1x/month
- No exercise induced symptoms
- Not affecting sleep and activity
- Normal lung function
> Mild persistent
- DS: >1x/week
- NS: >2x/month
- Exercise induced symptoms
- Affecting sleep and activity >1x/month
- PEFR/FEV1 >80%
> Moderate persistent
- DS: daily
- NS: >1x/week
- Exercise induced symptoms
- Affecting sleep and activity >2x/month
- PEFR/FEV1 60-80%
> Severe persistent
- DS: daily
- NS: daily
- Exercise induced symptoms
- Affecting sleep and activity >2x/month
- PEFR/FEV1 <60%
Causative organism for pertussis and its classical presentation + confirmatory test
- Causative: Bordetella pertussis
- Classic presentation: paroxysms of coughing, an inspiratory whoop, and posttussive vomiting
- Confirmatory test: PCR assays
Clinical manifestation of atopy disease
- Atopic dermatitis
- Food allergy
- Allergic rhinoconjunctivitis
- Asthma
MOA of ipratropium bromide
- Antagonist of muscarinic acetylcholine receptor, leads to bronchodilation and fewer bronchial secretions
Normal range for respiratory rate in children
- <2m: >60
- 2m - 1 y/o: >50
- 1-5 y/o: >40
- > 6y/o: >30
