Week 5: Restrictive Lung Diseases Flashcards
Describe the clinical symptoms & investigation findings associated with restrictive lung disease.
DYSPNOEA (exertion+rest); T1 RESP FAILURE; HEART FAILURE
inability to expand upon INSPIRATION
- diffuse & interstitial involvement
- restrictive FEV1:FVC
- ↓gas transfer
- V/Q mismatch
Define the major classes of ACUTE and CHRONIC restrictive lung disease (including occupational, granulomatous lung disease (sarcoidosis), idiopathic pulmonary fibrosis.)
ACUTE: DAD Syndrome (trauma, chem. insult, infection, IDIOPATHIC., VIRAL)
*exudative stage progresses to proliferative
=> epitheial fibrosis, scarring,
CHRONIC:
USUAL INTERSTITIAL PNEUMONITIS : IPF
GRANULOMATOUS DISEASE: SARCOIDOSIS; HYPERSENSITIVITY PNEUMONITIS
=> fibrosis endstage honeycombing
SARCOIDOSIS: pathology & diagnostic findings
F>M, young adults,
Type 4 Hypersens., epitheloid giant cell granulomas (non-caseating) + lymphoid infiltrate
Serum Ca2+, ↑ACE (granuloma): hypercalciuria, hypercalcaemia,
No Tx
HYPERSENSITIVITY PNEUMONITIS
Type 3+4 hypersens, organic Ag reactivity (centriacinar deposit epitheloid) pneumonitis, upper zone of lung
Acute -> Chronic
Causative Agents in Hypersens Pneumonitis
Thermophyllic actinomycetes, M. faeni, T. vulgaris => FARMER’S LUNG (“my thermometer is acting on my seat” the vulgar farmer said)
Bird/Animal protein
Fungi - asperigillus spp.
Chemicals
DAD Syndrome & Progression
DIFFUSE ALVEOLAR DAMAGE SYNDROME
Idiopathic/Multifactorial / Viral infection,
- EDEMA
- HYALINE MEMBRANE + PRECIPITATION
- INTERSTITIAL INFLAMM + FIBROSIS
- FIBROSIS
=> T1RESP FAILURE => DEATH
IDIOPATHIC PULMONARY FIBROSIS: pathophys and progression
USUAL INTERSTITIAL PNEUMONITIS. IDIOPATHIC.
Inflammation, Pneumocyte 2 hyperplasia, SMC and vasc. proliferation,
FIBROBLAST FOCI CHAOTIC
=> end-stage: peripheral adenocarcinoma risk factor
Causes of UIP
- drug poisoning
- LT viral infection
- asbestos
- connective tissue disease
Investigation of restrictive lung disease
Spirometry FEV1:FVC
- ↓RV
- ↓all volumes
SARCOIDOSIS Signs & Symptoms
- ERYTHEMA NODOSUM: red painful lesions on legs, self-limiting
- ANTERIOR UVEITIS: occular sarcoidosis
- SYSTEMIC LESIONS
- Granuloma focus around sites of scarring
- LUPUS PERNIO: nose. chronic sarcoid.
SARCOIDOSIS complications
>progressive resp failure > bronchiecstasis > aspergilloma > haemoptysis > pneumothorax
SARCOIDOSIS INVESTIGATIONS
cxr: hilar lymphadenopathy; paratracheal enlargement of nodes
pulm function, TB test, eye exam, biopsy
SARCOIDOSIS MGMT
NSAIDS
Topical steorids
Systemic steroids (prednisolone)
IPF Signs & Symptoms & Findings
(older patients)
- crackles
- significant clubbing
- fibrotic shadow (lower areas)
- traction bronchiecstasis / honeycombing
IPF Mgmt
IPF Clinic; Pulm rehab; O2 therapy; benzos for SOB?
Oral anti-fibrotic
Transplant*
Endstage fibrosis
- honeycombing
- basal + posterior fibrosis DIFFUSE
=> RFactor in Lung Ca. = periph. adenocarcinoma
OSA Syndrome Pathophys/ RFactor
- recurrent upper obstruction = apnoea,
-ve pressure draws pharyngeal + palate tissue together.
=> oxygen desat, snoring, apnoea/hypopnea
=> microarousal, poor conc., daytime hypersomnolence - heavy smoking, overweight
OSA syndrome Investigations
Epworth questionnaire
Overnight sleep study, EEG, EOG,, Grading
OSA Syndrome Tx
=> Wt. loss, alcohol avoidance, ?endocrine
=> CPAP: +ve pressure during sleep
=> mandibular repositioning splint
Narcolepsy Pathophys
Young age pres.
Familial: HLADRB11501, HLADBQ0602
Narcolepsy Signs & Symptoms & Findings
Cataplexy
Daytime Somnolence
Hallucinations
Sleep paralysis
*Low CSF orexin
Narcolepsy Tx
Modafinil: stimulant - sfx: arrhythmias
Venlaflaxine: serotonin - sfx: agitation, anxiety, dry mouth
Sodium Oxybate - sfx: nausea, dizziness,
Chronic ventilatory failure symptoms
- orthopnea: paradoxial abdominal wall motion
- ankle swelling
- morning headache (CO2 build up; vasodilation) + disturbed sleep
- chest infections
Chronic ventilatory failure causes
- airway diseases
- chest wall abn.
- muscle weakness
- central hypoventilation: obesity hypovent syndrome: night resp failure progress to morning
Chronic ventilatory failure Tx
O2 therapy
non-invasive ventilation
tracheotomy ventilation
Central Apnoea Vs obstructive apnoeas
CENTRAL: absence of respiratory drivei.e. detected by the absence of chest wall movement. (less common)
OBSTRUCTIVE: negative pressure generated by the respiratory movements of the chest wall draws the upper airway tissues inwards and obstructs the airway.
