Respiratory Flashcards
Formula for the A-a gradient
Fio2(Ppatm-Ppwater vapour) - (PaCO2/0.8) - PaO2
Causes of elevated A-a gradient
V/Q mismatch
Diffusion defect
Right to left shunt
Causes of hyperaemia with a normal A-a gradient
Alveolar hypoventilation
Low Fio2
Best predictive metric for IPF
FVC
What is the UIP pattern on HRCT
Traction Bronchiectasis
Subpleural Reticulations with basal predominance
Honeycombing
Two anti-fibrotic treatments considered in IPF
nintedanib and pirfenidone
Main side effect of Pirfenidone
Photosensitivity
In newly diagnosed asthma which will decrease exacerbations
ICS
Main cause of death in patients with stable moderate-sever COPD with no comorbidites
Cardiovascular
When should you consider introducing ICS in a patient with COPD
In the context of high eosinophil count
In former smokers which Abx can reduce infective exacerbations?
Azithromycin
A/E
Hearing loss
Gastrointestinal upset
Which intervention most effectively reduces disease progression in COPD?
Smoking cessation
Diagnosis of COPD
FEV1/FVC <0.70 with no reversibility
What is the most effective treatment in COPD to minima acute exacerbations, hospitalisations and symptoms?
LABA/LAMA combination
Note no improvement in underlying lung function
Also note that LAMA or LABA mono therapy is first line therapy
What additional puffer do you add in to a patient who has experienced an exacerbation of COPD?
ICS
Note increased risk of pneumonia
Antibiotics for infective exacerbation of COPD (fever, increased sputum production or change in sputum colour)
Doxycycline or Amoxicillin
+ Oral corticosteroids
What is Romuliflast?
PD4 inhibitor –> anti-inflammatory effects
Has been shown to reduce acute exacerbations of COPD
Effective strategies for smoking cessation
Pharmacological therapy + counselling
Nb: Combination NRT is more effective than single product
What benefits does NIV in patients with COPD derived T2RF deliver?
- Reduced intubation rates
2. Reduced hospital LOS
Effect of long term NIV
Reduced admission free survival
But ? reduced quality of life
Pharmacological addition in patients with COPD commencing palliative care treatment?
Daily long acting opioids (kapanol) + laxatives
Significant post-bronchodilator response
FER increases by 200ml and 12%
What feature is identifiable on PFT in gas trapping?
elevate RV/TLC
What feature is identifiable on PFT in gas trapping?
Elevated RV/TLC
Best test for negative predictive value in asthma?
Methacholine bronchoprovocation test
20% fall in Fev1
Fals positives in allergic rhinitis, CF, heart failure, COPD and bronchitis
When is nitric oxide increased in FENO testing?
Eosinophilic asthma.
Cardinal features of AVPA
1) Bronchiectasis on CT
2) Elevated IgE
Effect of ICS in asthma
Reduced airway remodelling
Down regulation of pro-inflammatory proteins
ICS = mainstay of treatment
ICS –> ICS+LABA –>
In which patients would you use Omalizumab in asthma?
Allergic Asthma (Positive RAST) with elevated IgE (IgE>30I/U)
In which patients would you use Mepolizumab in asthma
Eosinophilic asthma
- Peripheral eosinophils > 150/microL
- Sputum eosinophils > 3%
Mepolizumab monoclonal antibody to IL-5
When to consider a surgical lung biopsy in possible ILD?
Age <50
Atypical HRCT
Rapidly progressive disease
Note 1-2% mortality of elective surgical lung biopsy
Indications fort transplant in IPF
Patients <65
DLCO <40%
FVC <80%
Decrease in SPO2 88% (including on exertion)
Dyspnoea or functional limitation attributable to lung disease
CT findings in NSIP
Ground glass opacity
Reticular Opacity
Traction bronchiectasis
Diffuse - can have sub pleural sparing
Best investigation test for sarcoidosis
Endobronchial ultrasound guided hilar lymph node biopsy
Supportive
BAL: Elevated CD4:CD8
Diagnosis of Pulmonary Arterial Hypertension
PAP: >20
PCWP >15
WU > 3
Causes of pulmonary arterial hypertension
1) Connective tissues disease
2) HIV infection
3) Porta hypertension
4) Congenital heart disease
5) Schistosomiasis
Heritable forms of PAH are usually associated with
BMPR2 - inhibits smooth muscle proliferation and induces apoptosis
> Only 25% of patients with BMPR2 mutations
> 70-80% of familial PAH have BMPR 2 mutation (autosomal dominant with incomplete penetrance and variable expressibility)
What predicts mortality in patients with IPAH
Hypocapnea
RVEF <35%
PVR > 650 wood units
Which patients should be offered CCB in PAH type w1
Those who response to inhaled NO or IV epoprostenol
> MPAP >10mmhg drop then <40
Initial therapy for PAH?
Ambrisentan + Tadalafil
Initial testing for bronchiectasis (incomplete)
1) FBC/UEC
2) IGE + Specific IgE to Aspegillus
3) Immungolbuins
4) Sputum MCS + AFB
Treatment for frequent exacerbates (>3 or more exacerbations in the past 12 months)
Azithromycin
> Note QT prolongation (do ECG)
or
Erythromycin
In CF colonisation with which organism predicts for worse outcomes?
Burkholderia
Which subset of patients in CF benefit from Ivacaftor
G551D-CFTR mutation
Which subset of patients in CF benefit from Ivacaftor + Elexacaftor + Tezecaftor
Delta 508 Homozygotes/Heterozygotes
When to consider transplant in CF`
FEV1<30% Rapid decline Malnutrition + Diabetes Frequent exacerbations Relapsing or complicated pneumothorax ICU admission Recurrent haemopytisis
Indication for Omalizumab
Asthma with elevated IGE (“In law grandma edna - Oma)
Diagnosis of ABPA
1) Predisposing condition
- Asthma
- CF
2) Obligatory criteria
- Positive skin prick test or increased IGE levels to Aspergillus
- Elevated IgE concentration (>1000)
3) Other (2 must be present)
- Positive aspergillus precipitants or elevated IgE to A Fumigatus
- Radiology consistent with ABPA
- Total eosinophil count >0.5x10 in steroid naive patiens
