Respiratory Medicine Flashcards
(99 cards)
Small cell lung cancer paraneoplastic syndromes
ADH
ACTH - not typical, hypertension, hyperglycaemia, hypokalaemia, alkalosis and muscle weakness are more common than buffalo hump etc
Lambert-Eaton syndrome
Squamous cell lung cancer paraneoplastic syndromes
parathyroid hormone-related protein (PTH-rp) secretion causing hypercalcaemia
clubbing
hypertrophic pulmonary osteoarthropathy (HPOA)
hyperthyroidism due to ectopic TSH
Adenocarcinoma
lung cancer paraneoplastic syndromes
gynaecomastia
hypertrophic pulmonary osteoarthropathy (HPOA)
oxygen dissociation curve
Shifts to Left = Lower oxygen delivery
HbF, methaemoglobin, carboxyhaemoglobin Low [H+] (alkali) Low pCO2 Low 2,3-DPG Low temperature
oxygen dissociation curve
Shifts to Left = Lower oxygen delivery
What is the L rule
Low [H+] (alkali)
Low pCO2
Low 2,3-DPG
Low temperature
Shifts to L → Lower oxygen delivery, caused by
oxygen dissociation curve
Shifts to Right = Raised oxygen delivery
Raised [H+] (acidic)
Raised pCO2
Raised 2,3-DPG*
Raised temperature
‘CADET, face Right!’ for CO2, Acid, 2,3-DPG, Exercise and Temperature
What is transfer factor?
transfer factor describes the rate at which a gas will diffuse from alveoli into blood. Carbon monoxide is used to test the rate of diffusion. Results may be given as the total gas transfer (TLCO) or that corrected for lung volume (transfer coefficient, KCO)
Causes of a raised TLCO
asthma pulmonary haemorrhage (Wegener's, Goodpasture's) left-to-right cardiac shunts polycythaemia hyperkinetic states male gender, exercise
Causes of a lower TLCO
pulmonary fibrosis pneumonia pulmonary emboli pulmonary oedema emphysema anaemia low cardiac output
conditions may cause an increased KCO with a normal or reduced TLCO
pneumonectomy/lobectomy
scoliosis/kyphosis
neuromuscular weakness
ankylosis of costovertebral joints e.g. ankylosing spondylitis
Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)
Eosinophilic granulomatosis with polyangiitis (EGPA) is now the preferred term for Churg-Strauss syndrome. It is an ANCA associated small-medium vessel vasculitis.
Features of Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)
asthma blood eosinophilia (e.g. > 10%) paranasal sinusitis mononeuritis multiplex pANCA positive in 60%
Tidal volume
volume inspired or expired with each breath at rest
500ml in males, 350ml in females
Inspiratory reserve volume (IRV) = 2-3 L
maximum volume of air that can be inspired at the end of a normal tidal inspiration
inspiratory capacity = TV + IRV
Expiratory reserve volume (ERV) = 750ml
maximum volume of air that can be expired at the end of a normal tidal expiration
Residual volume (RV) = 1.2L
volume of air remaining after maximal expiration
increases with age
RV = FRC - ERV
Functional residual capacity (FRC)
the volume in the lungs at the end-expiratory position
FRC = ERV + RV
Vital capacity (VC) = 5L
maximum volume of air that can be expired after a maximal inspiration
4,500ml in males, 3,500 mls in females
decreases with age
VC = inspiratory capacity + ERV
Total lung capacity (TLC)
sum of the vital capacity + residual volume
Features of Cystic fibrosis
short stature diabetes mellitus delayed puberty rectal prolapse (due to bulky stools) nasal polyps male infertility, female subfertility
Causes of respiratory alkalosis
anxiety leading to hyperventilation pulmonary embolism salicylate poisoning* CNS disorders: stroke, subarachnoid haemorrhage, encephalitis altitude pregnancy
Features of allergic bronchopulmonary aspergillosis
bronchoconstriction: wheeze, cough, dyspnoea. Patients may have a previous label of asthma
bronchiectasis (proximal)
features of allergic bronchopulmonary aspergillosis
eosinophilia
flitting CXR changes
positive radioallergosorbent (RAST) test to Aspergillus
positive IgG precipitins (not as positive as in aspergilloma)
raised IgE
Management of allergic bronchopulmonary aspergillosis
oral glucocorticoids
itraconazole is sometimes introduced as a second-line agent