Restrictive lung disease Flashcards
d:intrinsic lung disease
disease of the lung itself
d: extrinsic lung disease
Thoracic/extra-thoracic
neuro-muscular
pleural diseases
consequences of intrinsic lung diseases
Restrict normal lung function; impaired gas exchange varying degrees of inflammation fibrous scar tissue Alveolar: inflammation Oedema; haemorrhage (vasculitides); infection
Name the 4 categories in interstitial lung disease
drug related/ association
Idiopathic
Interstitial
Pneumonia (IIP)
Granulomatous
ILDs eg
Sarcoidosis, EAA
other eg LAM, HX
d: idiopathic
relating to or denoting any disease or condition which arises spontaneously or for which the cause is unknown
describe the flow volume curve for a restrictive lung disease
same height so normal shape
normal PF
reduced volume
Describe what LFTs would show for a restrictive lung disease?
Restrictive pattern
↓Forced Vital Capacity (FVC) with FEV1/FVC >70
↓DLCO (<80% predicted)
disease of alveolar walls/lumen is extrinsic/intrinsic?
intrinsic
describe the pathophysiology of alveolar disease?
impaired alveolar gas exchange alveolar barrier to O2 exchange Alveolar-Arteriolar barrier (A-a gradient) CO2 exchange unimpaired alveolar ventilation normal CO2 very soluble and blown off
What happens to the PaO2, SaO2 and PaCO2 in alveolar disease
decreased
decreased
normal
d: DLCO
Diffusion capacity of carbon monoxide (DLCO)
- measures gas diffusion across alveolar-arteriolar barrier
d: single breath diffusing capacity
CO diffusion across alveolar-capillary barrier
if the DLCO is decreased, what diseases may it be?
Anaemia, Emphysema, ILDs, Pulmonary oedema, PE, pulmonary hypertension
why is DLCO used to monitor treatment in ILD?
more sensitive than FVC
egs of thoracic/ Xtra thoracic related disease
obesity; kyphoscoliosis; ascites; diaphragmatic palsy
d: kyphoscoliosis
describes an abnormal curvature of the spine in both a coronal and sagittal plane
d:ascites
abnormal build up of fluid in the abdomen
egs of neuro-muscular disorders
motor neuron disease
myasthenia gravis
d: myasthenia gravis
long-term neuromuscular disease that leads to varying degrees of skeletal muscle weakness The most commonly affected muscles are those of the eyes, face, and swallowing
egs pleural disease in extrinsic ILD
pleural thickening
mesothelioma
large Pleural Effusions
describe the pathophysiology of restrictive hypoventilation
- thoracic/extra-thoracic
- neuromuscular
Hypoventilation means impaired alveolar ventilation which means a rise in paCO2 and reduced paO2
ALVEOLAR GAS EQUATION
Obesity / kyphoscoliosis reduce chest wall compliance
Neuromuscular conditions reduced power of muscles involved in respiration
d: minute ventilation
breaths/min X tidal volume
what can an obese patient that can increase ventilatory drive and minute ventilation get?
simple obesity
obstructive sleep apnoea
what can an obese patient that cannot increase ventilatory drive and minute ventilation get
hypoventilation especially during sleep
-hypercapnia and hypoxemia
leads to OSA and obesity hypoventilation syndrome
symptoms of restrictive thoracic disease
Breathless on exertion
- Cough but no wheeze
- Finger clubbing
- Inspiratory Lung Crackles
- Central Cyanosis (if hypoxaemic)
- Pulmonary fibrosis can occur as end stage response to chronic inflammation
what is CO2 retention a sign of?
type 2 respiratory failure
what would ABGs of restrictive lung disease show?
Type I (paO2 <8kPa) or Type II respiratory failure (hypoxia with hypercapnia - pCO2>6 kPA) ↑ bicarb. = chronic hypercapnia
name some treatments of restrictive lung diseases
weight loss remove any trigger factor medical therapy procedures: intercostal drainage or ascetic drainage surgery: corrective spinal surgery lung transplant etc
name 3 supportive treatments
CPAP
non-invasive ventilation (NIV)
Oxygen
d: CPAP
CPAP is a treatment that uses mild air pressure to keep your breathing airways open. It involves using a CPAP machine
