DPLD, Resp Physiology, Transplant Flashcards
CHEST Videos, SEEK questions (206 cards)
Respiratory pressure associated with
(a) Inspiratory pressure associated with hypercapnia
(b) Weak cough/difficulty clearing secretions
(a) Max inspiratory pressure under (1/3) predicted normal associated with hypercapnia
(b) Weak cough expected with max expiratory pressure under 60
Most sensitive lung volume for obesity
ERV = expiratory reserve volume (amount you can exhale more after tidal volume exhalation)
Which lung volume decreases with age?
(a) Why does TLC remain the same?
(b) FEV1 reduction
Lung volumes with age- vital capacity reduces (inspiratory reserve volume + tidal volume + expiratory reserve volume) but residual volume increases
(a) TLC RTS because even though VC reduces, RV increases
(b) FEV1 reduces by 30 ml per year after age 30
What correlates with good DLCO maneuver?
(a) Inspired volume
(b) Duration of breath hold
Good DLCO maneuver
(a) Inspired volume at least 90% of vital capacity (TV + ERV + IRV)
(b) At least 10 second breath hold
Which drugs to hold before methacholine challenge?
Hold LAMA for at least a week
What is considered a positive methacholine challenge?
20% reduction in FEV1 from escalating doses of methacholine (up to 400 ug)
Who to consider for hypoxia altitude simulation testing?
PO2 lower at higher altitude- consider testing in pts with SpO2 under 92% correlating to PaO2 under 70
Minimal clinical importance difference for 6MWT
30m = minimal important difference for 6MWT
Which system is the limiting step for exercise in most healthy ppl?
Cardiovascular system (HR and stroke volume)
Not limited by vital capacity, in fact should have respiratory reserve (normal flow-volume loop, not at max MV) and normal gas exchange (no desat)
Desat of more than 5% from baseline is abnormal
What is the clinical diagnosis that fits the lung injury pattern of
(a) UIP
(b) DAD
Histologic pattern of
(a) UIP
If has a cause: CTD, asbestos, chronic HP, genetic disorders (ex: Hermansky-Pudlak syndrome)
If idiopathic = IPF
(b) Diffuse alveolar damage is the histologic finding of ARDS
If has a cause: infection, drugs, radiation
If doesn’t have a cause = AIP (acute interstitial PNA)
BAL findings characteristic of
(a) NSIP
(b) OP
(c) PLCH
BAL cells
Normal: 85% macrophages, 10-15% lymphocytes (slow immune cells, adaptive immune response), under 3% neutrophils (acute inflammation, innate immune response), under 1% eos
(a) NSIP = nonspecific interstitial PNA
over 20% lymphocytes, ‘BAL lymphocytosis’
(b) OP = mixed but high lymphocytes (20-40%) and neutrophils 10%, can have eos 5%
(c) PLCH pathognomonic- positive CD1a stain
Describe radiographic features of typical UIP
Radiographic features of UIP
-subpleural and basilar predominance
-reticular changes, bronchiectasis
-basilar honeycombing
-absence of other findings like ground glass or nodules (more c/w NSIP)
Describe histologic features of UIP
Histologic features that makes UIP
-fibroblast foci
-heterogeneity: normal lung next to fibrotic (homogenous more NSIP)- ‘patchy’ involvement
-basilar and peripheral predominant (as correlated on imaging)
-architectural distortion, honeycombing
-no features suggesting alternate diagnosis (granulomas)
NSIP
(a) Radiographic findings
(b) BAL findings
(c) Prognosis compared to IPF
NSIP
(a) Radiographically- ground glass, absence of honeycombing, possibly subpleural sparing
(b) BAL lymphocytosis (over 20%, when under 10% is nromal)
(c) Better prognosis than IPF in general, more likely to respond to steroids
How we subtype NSIP
NSIP now subtyped as
-cellular
-fibrotic
Normal BAL cell pattern
Normal BAL cell pattern
85% macrophages
10-15% lymphocytes (slower immune response, adaptive immune response)
Under 3% neutrophils (fast immune response, innate immune response)
Under 1% eos
Expect lymphocytic or neutrophilic BAL cell pattern in:
(a) IPF
(b) sarcoidosis
(c) NSIP
(d) ARDS
BAL cell pattern
(a) IPF- neutrophilic
(b) Sarcoidosis- lymphocytic (then CD4/8 elevated)
(c) NSIP- lymphocytosis (over 20%, normal under 10%)
(d) ARDS- neutrophilic (more acute inflammatory cells)
Differentiate histology of IPF from NSIP
Histologically
IPF- fibroblast foci, temporal heterogeneity (normal lung dispersed with fibrosis). subpleural/basilar predominance
NSIP- homogeneous, can have more cellular (inflammatory, lymphocytic) or fibrotic subtype
Expect lymphocytic or neutrophilic BAL cell pattern in:
(a) OP
(b) Fibrotic HP
(c) Infection
BAL pattern
(a) Organizing PNA- lymphocytic (slower inflammatory cells, adaptive immune response)
(b) Fibrotic HP- lymphocytic
(c) Infection: neutrophils (acute inflammatory cells, innate immune response)
Definition of IPF acute exacerbation
(a) Tx
Worsening symptoms/hypoxia with worsening infiltrates for up to 1 month without another cause (really exclude cardiac-induced pulmonary edema)
(a) No tx just supporitve
-anti-fibrotics to try to reduce incidence
Proven role of antifibrotics
Antifibrotics- both nintedanib and pirfenidone most strongly shown to reduce decline in lung function (specifically FVC)
-probably reduces exacerbations
Mechanism of nintedanib vs. pirfenidone
Nintedanib- TKI- blocks receptors of tyrosine kinases used in fibroblastic growth
Pirfenidone- anti-TGFbeta
Side effect profile nintedanib vs. pirfenidone
(a) Labs to monitor
Nintedanib- diarrhea
Pirfenidone- rash, nausea
(a) For both- baseline LFTs and LFTs q1-3 months
Hereditary syndrome with subtypes causing IPF with albinism and bleeding
Hermansky-Pudlak syndrome = autosomal recessive defect in lysosomes (intracellular protein trafficking)
Albinism (hair, skin)
Increased bleeding risk
Progressive pulmonary fibrosis, typically IPF pattern, in certain subtypes