SPN, Pleural Disease, Sleep Flashcards
Differentiate benign vs. malignant patterns of calcification for a solitary pulmonary nodule
Suggests benign etiology (ex: hamartoma) if calcification if diffuse (think granuloma), popcorn (think hamartoma) central, or laminar/concentric
Beware of malignant if stippled (dotted) or eccentric
Name features of a benign solitary pulmonary nodule
-calcification, more specifically diffuse popcorn concentric or central (think hamartoma, granuloma)
-fat containing (think hamartoma)
-vessel running in and out as you scroll (think AVM)
Hounsefeld units of
(a) Air
(b) Water
(c) Fat
(d) Bone
(e) Lung parenchyma
Hounsefield units- universal units for CT scan, based on arbitrary delineation of water as 0 and air as -1,000
So scale generally runs from -1,000 (air, all black) to +2,000 (bone or metal, all white)
(a) Air: -1,000
(b) Water: 0
(c) Fat: -35 to -40 Hu
(d) Bone: +2,000
(e) Lung parenchyma: -600 to -700 (has a lot of air in it…)
Aside from granuloma or hamartoma, what are other etiologies of solitary pulmonary nodules
-pulmonary AVMs (see vessels running in and out)
-lipoid PNA (fat containing)
-intrapulmonary lymph node (often peripheral, can be triangular shaped)
For what specific type of nodules do the Fleischner Society Guidelines refer to?
-incidentally found (so NOT for nodules found on lung cancer screening CT)
-not for immunocompromised
-not if have a feature suggesting benign nature (calcification, fat, vessel, peripheral and triangular)
So incidentally found solitary pulmonary nodules
Guideline recs for f/u of solitary solid pulmonary nodule incidentally-found based on size
Fleischner Society Guidelines for incidentally found solitary pulmonary nodule
Under 6mm: NTD (can continue annual cancer screening for those at high risk)
6-8mm: CT chest at 6-12 months for both low and high-risk groups
Over 8mm: F/u CT chest at 3 months vs. PET vs. tissue sampling
Guideline recs for f/u of multiple solid pulmonary nodule incidentally-found based on size
Multiple nodules:
Still if under 6mm no f/u needed, if high risk optional at 12 mo
Anything over 6mm: f/u in 3-6 months (so faster than SPN which is 6-12 mo)
Guideline recs for f/u of solitary ground glass vs. sub-solid pulmonary nodule incidentally-found based on size
Both ground glass and subsolid nodule: again if under 6mm: no f/u needed
If ground glass over 6mm: f/u 6-12 months (want to trend the solid component)
If part solid over 6mm: CT at 3-6 months
Give a Ddx for nodules based on 3 different types of distribution of CT
3 distributions of nodules
- centilobular- think HP, bronchiolitis (infectious or respiratory from smoking)
- perilymphatic- think sarcoid
- random- think hematogenous spread of either miliary infection (Tb or fungal) or metastasis
How to narrow diagnosis for multiple random nodules on CT chest
Random nodules
-homogeneous and tiny (1-3mm): think miliary Tb
-heterogeneous maybe ground glass or solid mixed think metastases
Describe classic nodular pattern of sarcoidosis on CT
(a) Galaxy sign
Perilymphatic nodules- so along interlobular septa, fissures, aka where the lymphatics go
(a) Nodules (representing granulomas) can coalesce into mass-like consolidations = galaxy sign
Describe the type of nodules seen here:
(a) Likely diagnosis
Centrilobular- spares periphery, hazy, in the middle of the lobule, equally separated b/c standard size of secondary lobule (smallest unit visible on CT chest)
(a) acute HP = diffuse centrilobular nodules
What is this pattern on CT?
(a) Location of the nodules
(b) Likely etiology
Y-shaped branching centrilobular nodules c/w tree-in-bud opacification due to bronchiolar obstruction causing dilation/impaction of the centrilobular nodule
(a) Tree-in-bud if a form of centrilobular nodules
(b) Mucoid impaction- can be from any acute infection, seen in asthma, MAI
Distinguish halo sign and reverse halo sign on chest CT
(a) Imaging features
(b) Buzzword diagnoses
Halo sign:
(a) central consolidation with surrounding ground glass classically representing hemorrhage
(b) angioinvasive aspergillus (or other fungal infection)
Reverse-halo sign = Atoll sign
(a) Central ground glass (central clearing) with denser consolidation crescenting around at least 3/4 circumference
(b) Organizing PNA, fungal infection, GPA, pulmonary infarct
What is Atoll sign on chest imaging?
Reverse-halo sign = Atoll sign
(a) Central ground glass (central clearing) with denser consolidation crescenting around at least 3/4 circumference
(b) Organizing PNA, fungal infection, GPA, pulmonary infarct
When may a pleural effusion due to CHF be exudative?
CHF effusion may be falsely exudative in s/o diuresis
-check out the albumin ratio to serum, aka likely that serum albumin is also reduced
Explain how can have a hepatic hydrothorax w/o ascites
Yes due to oncotic pressure pushing ascites up through diaphragmatic defects, but also can be due to negative intrapleural pressure (lungs draw in fluid from abdomen)
Diagnostic criteria for spontaneous bacterial pleuritis
(b) Mgmt
The other SBP = complication of hepatic hydrothorax
Diagnosis: either + culture with more than 250 nucleated cells (neutrophils)
or negative culture w/o evidence of PNA and more than 500 nucleated cells (neutrophils)
(a) Typically just need abx, don’t require drainage
What dx to consider if pt with nephrotic syndrome presents with exudative pleural effusion?
Think of pulmonary embolism
-high risk (about 20%) of PE in pts w/ nephrotic syndrome due to acquired protein S deficiency
Differentiate pleural manometry of normal vs. trapped lung
Pleural manometry in trapped lung- big pressure drop with removal of small amount of fluid
What is pleural elastance?
Pleural elastance- change in pressure of the pleural space per certain amount of volume removed
= dP/dV
ex: High pleural elastance in trapped lung where with small volume removal there is a big change in pleural pressure
-while normal needs a large volume removed to get a change in pressure
Differentiate trapped vs. entrapped lung
(a) Which may be reversible
Trapped = abnormally high pleural elastance due to fibrous thickening of the visceral pleura causing the pleural space to be irreducible
(a) Typically not reversible, may require decortication if pt very symptomatic
Entrapped = initially normal elastance (dP/dV) that becomes abnormally high as pleural fluid is removed, typically due to restriction of the visceral pleura from acute inflammation
(a) May resolve with treatment of the active pleural process
Describe physiology of transudative vs. exudative pleural effusion
Transudative- low protein fluid pushed against intact capillary membrane due to increase in hydrostatic pressure inside the capillaries
Exudative- fluid pushed against defective capillary membrane (due to inflammation- think infection, malignancy, rheumatologic) => allowing protein and cells (neutrophils, hence elevated LDH) to cross
Rare causes
(a) Parapneumonic effusion with high pH
(b) Transudative effusion w/ low pH
(a) Proteus PNA uniquely causes a parapneumonic effusion w/ elevated pH while other parapneumonic effusions will have low pH
(b) Urinothorax (urine in the pleural space) due to an obstructive uropathy = only cause of low pH transudative pleural effuison
Etiology of pleural effusion will cause what to pleural glucose
(a) Low
(b) Super low
(b) Normal
Pleural glucose typically mirrors pleural pH
(a) Low (under 60)- malignancy, infection, rheumatologic (lupus, rheumatoid), Tb
(b) Very low, like undetectable- think rheumatoid pleurisy or empyema
(c) Normal (mirrors serum) in transudative
3 most common causes of a lymphocytic pleural effusion
Malignancy, Tb pleuritis, and post-CABG
What is the typical cause of eosinophilic effusions (when eos are more than 10% of nucleated cells)
Nonspecific finding typically from trauma- reflecting blood (hemothorax) or air (penumothorax) in the pleural space
Positive beta-2 transferrin in pleural fluid is diagnostic for what?
(a) Clinical context
Beta-2 transferrin positive in duropleural fistula = fistula between subarachnoid space and pleural space (aka CSF in the pleural space)
(a) After trauma, spinal or CT surgery, or malignancy
Expected composition of pleural effusion due to perforated esophagus
L-sided effusion typically exudative with signs of inflammation (low pH, glucose under 60, LDH over 1000)
-L sided, very low pH (under 7.0), high salivary amylase (not pancreatic amylase)
Differentiate simple vs. complicated parapneumonic effusion
(a) pH
(b) Pleural glucose
(c) Pleural LDH
Simple parapneumonic effusion:
(a) pH over 7.2
(b) Glucose over 60 (more similar to serum)
(c) LDH under 1,000
Complicated parapneumonic
(a) pH under 7.2
(b) Glucose under 60- mechanism presumed that bacteria using up the glucose
(c) Pleural LDH over 1,000
MIST-1 vs. MIST-2 trial results
MIST-1: no improved outcomes with intrapleural tPA for empyema
MIST-2: tPa/DNase superior to either alone for empyema- reduced hospital LOS (by almost a week), reduced surgical referral, improved fluid drainage
Characteristics of pleural effusion associated with
(a) Pulmonary embolism
(b) Tb
(c) Pancreatitis
Pleural effusion
(a) PE- exudative, not uncommon (book says up to 20-50%), thought to be due to increased permeability
(b) Tb- exudative, low glucose, lymphocytic
(c) Pancreatitis- exudative, elevated amylase, typically L-sided
LIkelihood of AFB culture positivity in pleural fluid from TB pleuritis
Under 40% (so low sensitivity)
ADA is pretty sensitive (90%), use PCR
Pleural fluid studies to differentiate RA and SLE pleuritis
RA is uniquely low pH (under 7.2) and low glucose (under 60)
While SLE pleurisy expect normal pH and normal glucose (similar to serum)
Definition of hemothorax
Hemothorax: pleural fluid hematocrit at or above 50% serum Hct
Most common causes of cholesterol pleural effusion (pseudochylothorax)
Cholesterol effusion typically due to long-standing pleurisy (pleural inflammation) from Tb pleuritis or RA pleurisy
Chylothorax vs. cholesterol effusion
(a) Mechanism
(b) How to differentiate on pleural fluid studies
Both can look milky/opalescent but very different mechanisms, differentiate objectively by TG and chylomicrons
Chylothorax
(a) Lymphatic fluid (chyle) spills into pleural space due to damage or obstruction of thoracic duct
(b) Diagnostic TG over 110 with presence of chylomicrons
Cholesterol effusion from (a) chronic pleural inflammation (Tb or RA)
(b) No chylomicrones, TG under 110, total cholesterol over 220
Chylothorax vs. cholesterol effusion
(a) Main causes
Chylothorax (chyle in pleural effusion)- due to damage to or obstruction of lymphatic duct- iatrogenic (procedure) or malignancy
-characteristic presence of chylomicrons in pleural fluid
-pleural fluid cholesterol under 200
Cholesterol effusion (cholesterol in pleural effusion) due to chronic inflammation of pleural space, (a) typically Tb or RA pleurisy
-fluid cholesterol > 200
Differentiated more by cholesterol:TG ratio- higher it is, more likely cholesterol effusion vs. chylothorax
List causes of elevated amylase in pleural fluid
Amylase in pleural fluid-
-pancreatitis (acute or chronic), typically L-sided effusion
-esophageal perforation
-pulmonary malignancy
Triad of yellow nail syndrome
- Yellow/discolored, hardened nails
- Lung disease- typically pleural effusion but can be bronchiectasis or chronic sinusitis
- Lymphedema => swelling
Name 3 findings of benign asbestos-related pleural abnormalities
Asbestos-related pleural disease
- (15-20 year latency) benign asbestos- pleural effusion- often bloody, exudative, occasionally with eos
- 20 yr latency- pleural plaques, do not correlate with mesothelioma risk
- Rounded atelectasis- infolding of redundant pleura, can appear mass-like
Typically what is the earliest pleural finding of asbestos exposure?
- (15-20 year latency) benign asbestos- pleural effusion- often bloody, exudative, occasionally with eos
- 20 yr latency- pleural plaques, do not correlate with mesothelioma risk, calcifies over time (30+ years)
Comet tail sign on CT chest
Comet tail sign of rounded atelectasis- pulling of bronchovascular bundle leading to peripheral mass-like appearing consolidation of collapsed lung due to infolding of redundant pleura
-classically 2/2 asbestos exposure
-also pulmonary infarct, parapneumonic effusion, Tb
Normal intrapleural pressure at FRC
(a) Normal increase in intrapleural pressure with 2L pleural fluid in the hemithorax
Intrapleural pressure at FRC (RV + ERV, end of tidal exhale) is about -5
(a) Pleural pressure can increase to about +10
Differentiate lung entrapment from trapped lung
(a) Etiology
(b) Pleural pressure change
(c) Reversibility
Entrapped lung (b) Can remove some pleural fluid with normal drop in pleural pressure, but then when remove a lot get a precipitous drop in pleural pressure
(a, c) typically more reversible etiology of pleural inflammation like infection causing thickening of visceral pluera, also from endobronchial obstruction
vs.
Trapped lung (b) with removal of just 500cc get precipitous drop in intrapleural pressure
(a,c) Chronic more difficult to reverse process, typically visceral pleural scarring
Explain how to use pleural manometry to reduce risk of re-expansion pulmonary edema
Normal intrapleural pressure at FRC is around 0 to neg 5, when accumulates fluid can rise to ~+10
While draining fluid stop when pleural fluid starts to approach -3 to -5 to prevent re-expansion pulmonary edema.
If yoiu stop by pleural manometry or when pt reports chest pain there is very low risk of reexpansion pulmonary edema
Explain how to use pleural manometry to predict risk of pneumothorax ex vacuo
PTX ex vacuo when the lung cannot re-expand- see a drastic drop in intrapulmonary pressure with removal of not a lot of fluid. So if see intrapleural pressure on manometry drop to way below -5 esp with removal of just 500-750cc of fluid think PTX ev vacuo
For an exudative pleural effusion differentiate meaning of elevated protein vs. elevated LDH (what do they signify about the effusion)
Elevated protein indicates broken capillary barrier => proteins can leak
Elevated LDH indicates high inflammation => lots of cells and turnover
What additional pleural fluid test can be helpful to differentiate heart failure effusions falsely classified as exudates?
Up to 25% of transudative effusions can be falsely classified as exudative, especially in s/o diuresis
Can use pleural fluid cholesterol to help differentiate, pleural fluid cholesterol over 55 suggests exudative
Things that can falsely change the pH of pleural fluid
(a) Falsely increase pH
(b) Falsely lower pH
(a) Falsely increase pH (reduce sensitivity for complicated effusion) in excess air in the syringe and excess time until processing
(b) Lidocaine can falsely lower pH detection
Tricks to improve accuracy of pleural pH measurement
(a) What measure may be used as a surrogate?
Put on ice, push out air bubbles, get to lab within an hour. (air and time in syringe can falsely increase pH). Try to avoid lidocaine in syringe (can falsely drop pH)
(a) Glucose can potentially be used as a surrogate b/c low glucose often seen in same things that have low pH (empyema)
Pleural fluid studies diagnostic for spontaneous infection of hepatic hydrothorax (spontaneous bacterial pleuritis)
Either
-ANC over 250 with positive culture, or
-ANC over 500 with negative culture
What determines whether chylothorax will be R or L sided?
Depends where the injury (or obstruction) is to the thoracic duct. Around level of T5 thoracic duct migrates from R to L
so below T5 => R chylothorax
above T5 => L chylothorax (then thoracic duct drains into L subclavian
Pleural fluid studies to differentiate lupus from rheumatoid pleuritis
Mostly differentiate by LDH and glucose
RA: expect LDH over 1,000, strikingly low glucose often under 30
elevated RF
What syndrome to suspect when pt with uterine fibroids presents with pleural effusion
Meig’s syndrome: pleural effusion, ascites, benign ovarian mass (fibroma), often elevated CA-125
-association of adnexal mass with ascites and pleural effusion
Tx = remove the adnexal mass to resolve the ascites and pleural effusion
Differentiate characteristics of early vs. late post-CABG pleural effuions
Early (within first 30 days) expect bloody and possible eosinophilic
Late (after 30 days) expect lymphocytes, non-bloody
Most common bugs causing pleural infection
(a) community acquired
(b) nosocomial
(a) 85% pleural infections community acquired
-most common (70%) strep
-2nd with 15% staph
(b) 15% hospital acquired
-Most common (40%) staph, then 25% gram negatives
Outcomes of MIST-2 trial
MIST-2 NEJM 2011: tPA + DNase superior to either alone for reducing surgical referral, hospital LOS, and improving drainage/radiographic outcomes for pts with complicated parapneumonic effusions or empyema
-not reduced mortality
What marker can be added to pleural ADA to increase specificity of TB pleuritis to nearly 100%?
IL-27
What disease to consider in pt with spontaenous PTX and the following skin finding
Fibrofolliculomas (benign hamartomas of hair follicles) + cystic lung disease (25% risk of pneumothorax)- think Birt-Hogg-Dube due to autosomal dominant mutation in folliculin gene
folliculin gene mutation => loss of function of tumor suppressor gene
Per guidelines which PTX can potentially be discharged from the ED?
Primary spontaneous PTX that is small
-primary only, not secondary: so no underlying lung disease. underlying lung disease => should get admitted
-small meaning under 3cm from apex to cupola
Can manage by watching in ED for 3-6 hrs then sending home w/ f/u CXR next day
Primary spontaneous PTX
(a) At what size requires drainage?
(b) Recurrence rate
(c) When to consider procedure to prevent recurrence
Primary spontaneous PTX
(a) Over 3cm from apex to cupola (top of chest wall to top of lung) requires admission and drainage- under 3cm can consider expectant management and d/c home
(b) Recurrence rate 25-50% in the first year
(c) Don’t pleurodese after the first, consider after the second
Clinical story hint to consider thoracic endometriosis in patient with spontaneous pneumothorax
Catamenial symptoms- so chest pain and PTX during time of menses
Which carries higher risk of PTX: Birt-Hogg-Dube vs. LAM?
BHD- about 25% risk of PTX
-folliculin gene mutation
-associated skin fibrofolliculomas and kidney tumors
vs.
LAM- about 50% lifetime risk of PTX
-TSC gene mutation
-associated renal angiomyolipomas
Top 3 most common cancers causing malignant pleural effusion
Lung –> breast –> lymphoma
Describe process of talc pleurodesis
First drain all fluid (want the pleural surfaces as together as possible)
Then talc pleurodesis- mix 4g talc with normal saline, inject into chest tube (can be either small or large bore) then keep it clamped for an hour. (can have patient shift around to try to distribute talc) then unclamp and let drain to suction, then take out chest tube when drainage low for 24 hrs
Describe mechanism by which medical pleurodesis is supposed to work
Thought is to cause inflammation/fibrosis that adheres the visceral and parietal pleura together
First line- talc
Others- doxycycline, bleomycin
TIME-1 trial:
(a) NSAIDs vs. opiates for chest tube analgesia
(b) Small vs. large bore chest tube for empyema
TIME-1 trial for chest tube placement
(a) No difference in pain scores or rates of pleurodesis for NSAIDs vs. opiates
-try to use NSAIDs before opiates
(b) Small bore obviously less pain, trend towards noninferior but not significant
What did the ASAP trial (AJRCCM 2017) tell us about best frequency of pleurX drainage
ASAP trial- compared q24 hr to q48 hr of pleurX fluid drainage- showed more frequent drainage (q24h) had better rate of pleurodesis
-median time to autopleurodesis was 54 days
=> standard of care is daily drainage for median of 54 days
What did the IPC-Plus trial (NEJM 2018) tell us about talc via intrapleural catheter vs. placebo for rate of pleurodesis
IPC-Plus: for patients with intrapleural catheter in place, put talc in vs. placebo, pts who got talc had double the rate of pleurodesis
So can put talc through a pleurX! (assuming not a trapped lung)
Differentiate the two types of asbestos forms
(a) which more carcinogenic?
Asbestos refers a group of silicates that exist in a fibrous form, 2 types
(a) Serpentine- spiral shaped and pliable, accounts for large majority (90+%) of exposures in the US, less carcinogenic
(b) vs. amphiboles- rigid, needle-like, can penetrate through lung into pleural surface
more carcinogenic
Environmental risk factors for asbestos exposure
Ship building, plumbers, pipefitters, mechanical engineer, ship/boat building,
Typical latency period for
(a) pleural plaques
(b) asbestos-related pleural effusion
(c) mesothelioma
(a) pleural plaques- 20ish years
(b) asbestos-related pleural effusions can have the shortest latency period, can develop within 1-20 yrs of exposure
(c) Mesothelioma after typically 30+ yrs
Preferred management for trapped lung causing malignant pleural effusion
For trapped lung due to malignant cause can still consider intrapleural catheter (pleurX) b/c then patient can drain fluid gradually and stop at any pain (when pleural pressure gets too negative)
Main advantage of intrapleural catheter over talc pleurodesis
IPC- outpatient procedure, vs. 6-7 day LOS stay for pleurodesis
-similar improvement in quality of life, dyspnea, similar cost (given initial hospital costs offset by pleurX supply catheters)
In hospital acquired parapneumonic effusion what is the most commonly identified organism
Staph
(in community acquired is strep)
Where are the pleural lymphatics located?
(a) Visceral vs. parietal
(b) Mediastinal vs. distal/peripheral flow
(a) pleural fluid drains via openings directly from the parietal pleura
- while visceral lymphatics drain the lung parenchyma, not generally the pleural space
(b) Drains medially/through mediastinum
Dosing of intrapleural medications for empyema per MIST-2 trial
MIST-2: NEJM 2011, tPA (10mg) + DNase 5mg twice a day x3 days
MIST-2 trial outcomes
Intrapleural tPA (10mg) + DNase (5mg) BID x3 days (so max 6 doses)
improved primary outcome of radiographic improvement
also reduced hospital LOS and need for surgical consult
Stage of sleep
(a) Most of night spent in
(b) K-complexes
(c) Delta waves
(d) Sleep spindles
Sleep stages
(a) Most of the night spent in N2 sleep (K-complexes, sleep spindles)
(b) K-complexes = stage 2
(c) Delta waves = stage 3
(d) Sleep spindles = stage 2
What happens to the duration of REM as the night goes on
REM duration increases throughout the night, REM periods occur every 90-120 minutes and become longer as the night goes on