Respiratory Flashcards
what is Elastic recoil
tendency for lungs to collapse inwards and chest wall to spring outwards
what is compliance and when is it changed
change in lung volume and pressure is inversely proportional to wall stiffness
increased by surfacant
increased means easier to fill (elderly, emphysema)
decreased more difficult (fibrosis, pneumonia, ARDS, oedema)
Pulmonary wedge pressure is the equivalent of?
pressure of LA
A-a gradient
normal = age/4 + 4
normal in high altitude or hypoventilation
raised in diffusion limitations (fibrosis), V/Q mismatch (COPD, oedema, PE) or R -> L shunt
Causes of right shift of O2 dissociation curve
CADET looks right
CO2 increased
acidosis
DPG increased
Exercise
Temp increased
What is eisenmengers syndrome
Left to right shunt becomes right to left due to pulm HTN
Cyanosis, clubbing, hypoxia
Cyanide symptoms
headaches, SOB, drowsiness, seizure, cherry red skin, red venules in retina , bitter almond breath
Cyanide poisening lab findings
normal pa02, elevated lactate (HAGMA)
Cyanide treatment
decontamination
hydroxocobalamin
sodium thiosulfate
Carbon monoxide poisening labs
normal Pa02, raised carboxyHb
CO poisening treatment
100% O2
hyperbaric if severe
Methhaemoglobinaemia treatment
Methylene blue and Vit C
Most common type of head and neck cancer
squamous cell carcinoma
Fat emboli etiology and sx
long bone fractures and liposuction
hypoxia, neuro (reduced GCS, confusion, seizures) and petechial rash
Head and neck cancer tx
pembro and chemo better
PDL >20% can do pembro only
PDL 1-20% - pembro and chemo (5FU and cisplatin)
PDL 0% - chemo only
Asthma is example of which hypersensitivity
Type 1
Usual age of diagnosis of idiopathic pulm fibrosis
60s
HRCT pattern of idiopathic pulm fibrosis
UIP (subpleural reticular opacities, honeycombing, traction bronchiectasis)
Peripheral and lower lobe predominance
Treatment for idiopathic pulm fibrosis
supportive with oxygen
antifibrotics (pirfenidone or nintedanib) -> reduced PFT decline
Type of hypersensitivity in hypersensitivity pneumonitis
T3 and 4 mixed
(thermophilic actinomyces and asperigillous)
Difference between acute vs chronic hypersensitivity pneumonitis
acute -> agent triggers IgG Ab -> inflammation and neutrophils
chronic -> CD4 Th1 delayed hypersensitivity TLR 2 and 9 pathways
Th1 and Th17 promote lung inflammation
Hypersensitivity pneumonitis HRCT findings
mid-upper zone prodominance of centrilobar ground glass and mosaic attenuation
Sarcoidosis classic grnaulomas made of
non-necrotising with tightly packed central area with macrophages, epitheloid cells and multinucleated giant cells with CD4 T cells surrounds by CD4 and 8 T and B cells
What is lofgren syndrome
sarcoidosis
bilateral hilar adenopathy plus erythema nodosum plus periarticular arthritis
2 common/specific skin conditions to sarcoidosis
erythema nodosum
lupus pernio
Lab findings in sarcoidosis
raised ACE levels
hypercalcaemia
BAL raised CD4/8 ratio
Mesothelioma cell markers
calretinin
cytokeratin 5/6 in almost all
(carcinomas are -ve)
Treatment for mesothelioma
chemo (cisplatin and pemetrexed)
2nd line vinorelbine
RTx for chest wall pain
Distribution of lung involvement asbestosis and berylliosis/silicosis/coal workers
asbestos in the roof so affects the base of lung
Beryllium/silica/coal in the ground so affects the upper lobes
What is caplan syndrome
RA plus pneumoconioses with intrapleural nodes
Most likely cancer with asbestos related lung disease
bronchogenic carcinoma
(mesothelioma less likely)
Berylliosis histology findings
non-caesating granulomas
Berylliosis lab findings
raised blood beryllium lymphocyte proliferation test (BeLPT)
Berylliosis treatment
cessation of exposure
if cough, for reduced FVC/TLC/DLCO <70% then glucocoticoids
Silicosis why increased TB risk
disrupt phagolysosomes and impair macrophages
ARDS treatment
mechanical ventilation - reduced TV and increase PEEP
Obstructive sleep apneoa diagnosed as
> 5 apnea/hypopnea events per hour if symptomatic
if asymptomatic >15 events per hour (resp distrubance index >15 per hour)
What testing appropriate in sleep apnea
if mild OSA or complicated/other sleep disorders -> formal PSG
if mod/severe OSA -> home testing
Ventilation changes in obesity
decreased FRC, lung compliance and TLC
Diagnosis of pulmonary arterial HTN
mPAP >20, PVR > 2 wood units
PCWP <15 to exclude LHD
Gene which is cause of heritable pulmonary artial HTN
BMPR2 gene (normally inhibits vascular smooth muscle proliferation)
- inactiviating mutation
Treatment for vasoreactive PAH
CCB
treatment for non-vasoreactive PAH
class 1 sx -> monotherapy PDE5, ERA or riociguat
class 2/3 sx -> dual ERA and NO-cGMP therapy
clas 4 -> protanoid combo (epoproterol preferred)
Left heart disease pulm HTN diagnosis
mPAP >20 and PCWP >15
imaging for CTEPH
V/Q best screening, CTPA can help
DSPA is gold standard for confirming and assessing for surgery eligibility
CTEPH treatment
lifelong anticoagulation
if haemodynamically sig (PVR at rest 2-15 units) -> consider thromboendarterectomy
If surgery not an option, riociguat is first line
Cause of clubbing
Plt and megakaryocytes lodge in digital vasculature -> local release of VEGF
associated with pulm fibrosis, cystic fibrosis, bronchiectasis, congenital heart disease, IBD
Lights criteria for effusions
pleural LDH/serum LDH >0.6
pleural protein/serum protein >0.5
pleural LDH > 2/3 ULN
uncomplicated parapneumonic effusion vs complicated
uncomplicated - low glucose, low pH, raised PMNs
complicated - lower glucose, very high LDH, lower pH <7.15, raised PMNs
TB effusion findings
raised ADA
pancreatitis associated pleural effusion findings
raised amylase
chylothorax findings
TGLs > 1.24
PTX treatment
if <2cm and stable - observe
if >2 cm and stable -> aspirate first
if recurrent -> chest drain
if secondary -> VAT, 2nd line non-surg pleurodesis or prolonged chest drain
common bugs for lobar pneumonia
s pneumoniae
legionella
klebsiella
common bugs for bronchopneumonia
s pneumoniae
s aures
H influenzae
klebsiella
Where does lung cancer tend to metastasis
liver, adrenals, bone, brain
What cancers give mets to lung
breast, colon, prostate and bladder
Small cell treatment for stage 1 and 2/3
surgery -> adjuvant cisplatin
if LN involvement in 2/3 -> chemo only
extensive stage SCLC
carboplatin and etoposide plus maintence durvalumab
conditions associated with SCLC
neurological paraneoplastic
Endocine (cushings due to secretes ACTH and SIADH)
SCLC mutations
myc oncogenes
Which is most common NSCLC
Adenocarcinoma
driver mutations of adenocarcinoma
EGFR 10-35%
ALK 3-7%
ROS1 1%
KRAS
Chemotherapy for NSCLC without mutations
cisplatin plus pemetrexed
add pembrolizumab if PDL1>1%, if >50% pembro only
Treatment if EGFR mutation
Erlotinib
What do to if NSCLC EGFR positive progresses on erlotinib
check for T790 mutation -> if present give osimertinib
treatment if ALK mutation in NSCLC
crizotinib or alectinib
Treatment if NSCLC ROS1 positive
crizotinib
Common metabolic issue with squamous cell lung ca
high Ca (secretes PTHrP)
associated condition with large cell carcinoma lung cancer
gynaecomastia (secretes HCG)
carcinoid syndrome associated with what vit deficiency
B3 -> cause pellagra (inflammed skin, diarrhoea, dementia, mouth sores)
Bronchial carcinoid tumour prognosis and associated sx
good prognosis
carcinoid syndrome
MoA of bosentan
endothelin-1 receptor antagonist which decreases pulm vascular resistance
ADR: hepatotoxic
MoA of sildenafil
Phosphodiesterase 5 inhibitors -> raises cGMP which prolongs vasodilatory effect of NO
MoA of iloprost, epoprostenol
Prostacyclin analogs, direct vasodilatory effects on pulm vasc and systemic arterial vascular beds
ADRs: flushing, jaw pain
MoA salbuatmol and formeterol
one is short, one is long acting beta-2 agonists
MoA of tiotropium, ipratropium
muscarinic antagonists, prevents bronchoconstriction
MoA omalizumab
binds unbound IgE so cant bind to Fc portion of mast cells
throphylline MoA
likely a PDE inhibitor -> bronchodilation
MoA mepolizumab
anti IL5 -> prevents eosinophils differenciation, activation and survival
Severity of obstruction grading in PFTs
mild >70
mod 60-70%
mod severe 50-60
severe 35-50
very severe <35
Main 2 antifibrotics and MoA
Pirfenidone - TGFB and reduces fibroblast proliferation
Nintedanib - inhibits multiple tyrosine kinases
Both slow disease progression and improves survival, no sx benefit
Pirfenidone ADR
nausea
photosensitvity rash
Nintedanib ADR
diarrhoea
weight loss
possible CVD risk
can increase bleeding risk, avoid on anticoagulation
Most comon mutation pathway involved in idiopathic pulm fibrosis
mutations involving premature shortening of telomeres
Pattern of lung disease in RA
UIP
Pattern of lung disease in Systemic sclerosis
NSIP
pattern of lung disease in inflammatory myopathies
oragnising pneumonia
pattern of lung disease in sjogrens
lymphoid interstitual pneumonia
Names of smoking related ILDs
respiratory bronchiolitis - ILD
desquamative interstitual pneumonia
fulminant langerhans cell histiocytosis
mutation seen in 50% IPF
MUC5b gain of function
Mutation causing amyotrophic dermatomyositis with ILD
anti-MDA5
imaging findings in lymphangioleiomyomatosis
pulmonary cysts and renal angiomyolipomas
antibody associated with primary alveolar proteinosis
GM-CSF
What is sampter’s triad
asthma
aspirin intolerance
nasal polyps
findings of ABPA
very high total IgE >1000
Omalizumab target
IgE
Mepolizumab target
IL 5 (main cytokines responsible for differenciation of eosinophils)
Benefits and risks of triple therapy in COPD vs double
triple have reduced exacerbations and hospitilisation, but increased pneumonia risk
Most common cause of bactyerial exacerbations of COPD
haemophilis, streptococcus, moraxella
3 most common causes of pleural effusion
malignancy
HF
infection
pH indicated by parapneumonic effusion
< 7.2
Benefit of inhaled hypertonic saline in bronciectasis?
Reduce exacerbations
some QOL improvement
Pathophysiology of cystic fibrosis
CFTR usually allows Cl to leave the cell, if not able to leave, increase in Na uptake from lungs via ENaC, which brings water with it, drying out secretions
Cystic fibrosis mutations
DF508
G551D
Ivacaftor MoA
CFTR potentiator (opens channel of protein)
used in homozygous DF508 mutations
Cystic fibrosis criteria for lung transplant referral
FEV1 < 35%
increase freq of IV abx
pO2 < 60
pCO2 >50
clinical organism resistance
imapired QOL
Pathways for treatment of PAH
endothelin
NO
Prostacyclin
If evidence of precappillary PAH on RHC, which test would you do and why
Vasodilator challenge
- eligible for CCB
RHC measurements for PAH
mPAP >20
if precapillary PAWP <15
if PAWP >15 suggests left heart failure (no vasodilator therapies)
Why are you unable to use vasodilators for group 2 (LV failure) PAH
worsening pressure gradient over alveolar bed -> pulm oedema
Cardiac sequale post pneumonia
new onset HF caused by bacterial translocation into myocardium
Normal characteristics of REM sleep
atonia on EMG and tonic/phasic eye movements
second half of night
definition of apneoa
cessation of airflow for > 10 secs
Definition of hypopneoa
reduction in airflow by 30% or >10 secs followed by 4% O2 desat or EEG arousal
apneoa-hypopneoa index severity
normal < 5
mild 5-15
mod 15-30
severe >30
Benefits of CPAP
improves daytime sleepiness, depression, cognitive function, QOL, BP, MVA risk
does not change CVD mortality
Leptins role in ventilation and OSA
leptin is a respiratory stimulant, if leptin resistance (ie in obesity) then can lead to hypoventilation
Difference between Narcolepsy T1 and T2
T1: with cataplexy, low Orexin on CSF
T2: without cataplexy, normal orexin
Both have >3mo excessive daytime sleepiness and positive multiple sleep latency tests (<8 mins to sleep)
Pathophysiology of narcolepsy
Autoimmune destruction of hypothalamic neurons which produce orexin (usually regulate arousal and transition between wake and sleep)
What is cataplexy?
sudden and transient episode of muscle weakness, asscoiated with concious awareness usually triggered by emotions ie laughing
