Pleural Effusion and Pneumothorax Flashcards
What does the visceral pleura cover?
surface of lungs and interlobar fissures
What does the parietal pleura cover?
surface of chest wall
diaphragm
mediastinum
How are the surfaces of the visceral and parietal pleura different?
visceral: the mesothelial cells are loosely arranged but have very tight junctions (bumpy) and they have very dense microvilli
parietal: the mesothelial cells are very tightly arranged but have leaky tight junctions with very sparse microvilli
Describe are the components of the pleura?
mesothelial cells, BM, CT with blood vessels, lymphatics, and nerves
Describe the normal pleural fluid.
Clear, odorless with mostly macrophages (some lymphocytes and few polys)
Its function is to lubricate the pleural surface
What determines the amount of pleural fluid formed?
HP and OP balance
tissue pressure
lymphatic drainage
F = K (HPc-HPpl) - (OPc-OPpl)
Describe how the normal movement of pleural fluid and (include how much in ml/hr)
HP in the parietal pleura > HP in visceral pleura
(HP systemic circulation > HP pulmonary circulation)
this HP gradient drives the movement of fluid from the parietal layer into the pleural space thru mesothelial junctions. The fluid is them absorbed by the visceral pleura
**the oncotic pressure of the parietal and the visceral pleura are = and therefore does not oppose the HP gradient
100 ml/hr fluid formed –> 300 ml/hr fluid absorbed
Lymphatic drainage is present in (parietal or visceral pleura). * Why is this significant???
parietal
To transport cells and protein out of the parietal pleura to maintain low OP and maintain the balance so that fluid moves parietal –> space –> viceral ???? not sure she never really explained this, it is just my reasoning….
What are the 2 types of pleural effusions?
exudates and transudates
high pro and low pro
Increased HP will form (transudate or exudate)
trans
decreased pleural pressure will form (transudate or exudate)
trans
decreased oncotic pressure will form (transudate or exudate)
trans
increased oncotic pressure will form (transudate or exudate)
exudate
CHF will form (transudate or exudate). Why?
transudate bc the pulmonary artery HP > OP which causes the visceral pleura to shift from fluid absorption to fluid production
What are addnl characteristics of pleural effusion due to CHF
bilateral + cardiomegaly
How can malnutrition lead to a pleural effusion?
transudate or exudate
the decrease in plasma OP causes fluid to shift out of capillaries and into the pleural space from both the parietal and visceral sides
*transudate
How can atelectasis cause pleural effusion?
transudate or exudate
the collapse makes the pleural pressure more negative –> causes the HP gradient to become > OP gradient –> fluid formation from both sides
*transudate
How does inflammation cause pleural effusion?
transudate or exudate
inflammation increases vascular permeability –> leakage –> OP gradient decreases –> fluid moves into pleural space from both sides
*Exudate
With a large pleural effusion:
RR (inc or dec)
Chest expansion (inc or dec)
fremitus (inc or dec)
RR increases
Chest expansion decreases
fremitus decreases
What type of effusion will an increase in permeability lead to?
exudative
Why are diminished or absent breath sounds a sign on pleural effusion?
the lung is farther ways from the chest wall
**i thought liquid transmitted sound waves better then air though..?
What is the most common eitiology of pleural effusion?
CHF
What is the most common noncardiac etiology of pleural effusion? 2nd most common?
- neoplastic
2. infectous
What types of neoplasms most commonly cause effusions? Why?
lung and breast
*close proximity to pleura
What are the 2 forces that control the arrangement of free fluid in the pleural space?
- gravity
2. elastic recoil of lung (aka how much it relaxes during expiration)
What is the first radiologic sign of pleural effusion? Later/when it gets bigger?
- blunting of costophrenic angle
2. meniscus sign
What is the purpose of obtaining a lateral decubitus film?
once you suspect an effusion from an AP or PA CXR you can look at a lateral decubitus film to see if the fluid moves with gravity doue to the change in position = proves it is a fluid
If you see evidence of an effusion + an infiltrate, you might suspect …
parapneumonic effusion
If you see evidence of an effusion + a mass or nodule, you might suspect …
carconoma of the lung
lymphoma
mesothelioma metastatic carcinome
If you see evidence of an effusion + a wedge shaped infarct, you might suspect …
PE
If you see evidence of an effusion + cardiomegaly, you might suspect …
CHF
If you see a pleural effusion without any other radiologic abnormalities what diseases might you suspect?
TB or viral pleurisy pancreatitis Lupus or RA PE Low albumin = Nephrotic syndrome or chirrosis
What is the indication for performing a thoracentesis?
> 10 mm on lateral decubitus XR
What does a reddish tinged to bloody pleural fluid sample suggest?
if not traumatic tap..
- tumor
- pulmonary infarction
- trauma
- post cardiac syndrome
- asbestosis
**due to RBCs in sample
What does a turbid/cloudy pleural fluid sample suggest?
infection (including TB)
What does a turbid/cloudy green pleural fluid sample suggest?
rheumatoid pleuritis
What does a cloudy, milky white pleural fluid sample suggest?
Chylothorax
= disruption of thoracic duct from trauma or tumor
What is an empyema?
puss is the pleural effusion
What does a thick, bloody effusion sample suggest?
malignant mesothelioma
What is a chylothorax
milky white pleural effusion = collection of lymphatic fluid
*usually due to trauma to the thoracic duct
What are lights criteria for distinguishing between transudate and exudate?
one ore more of the following:
- Pleural/serum protein ratio:
transudate: 0.5 - Pleural/serum LDH ratio:
transudate: 0.6
- Pleural/serum LDH ratio:
- Pleural LDH
transudate: 200 U/L
What are the most common causes of transudative pleural effusions?
CHF, Nephrotic syndroms, cirrhosis w/ ascites
What are the most common causes of exudative pleural effusions?
parapneumonia effusion
malignancy (bilateral)
PE
collagen vascular disease (lupus, RA, scleroderma) (bilateral)
pancreatitis (usually left sided)
TB
postcardiac injury syndrome (=pericarditis, so inflammation just spills over?)
WHat are common causes of BILATERAL Effusions
malignacy
lupus, RA
nephrotic syndrome, cirrhosis w/ascities
esophageal rupture
What does a lot of lymphocytes in an pleural effusion make you think?
exudate + chronic inflammation + TB, Malignancy, sarcoid, RA
What does a lot of neutrophils in an pleural effusion make you think?
What about >50K/microL of neutrophils?
exudate + acute inflammation + paraneumonic, pancreatitis, or pulmonary infarction
paraneumonic
What is the definitive diagnosis if you find ___ in the thoracentesis sample?
- ADA
- KOH
- high triglycerides (>110)
- high amylase and pH 6
- Hct PF/blood >/= 0.5
ADA = TB KOH = funcgus high triglycerides (>110) = chylothorax high amylase and pH 6 = esophageal rupture -Hct PF/blood >/= 0.5 = hemothorax
What does >5% mesothial cells in thoracentesis sample mean?
it is NOT TB
How do you identify wether or not the effusion sample is from a traumatic thoracentesis or is actually blood that has been there due to an underlying condition?
if the sample is allowed to sit and it clots within minutes, it is fresh blood = traumatic thoracentesis
What does low glucose in pleural fluid sample suggest? (<60 mg/dl)
rheumatoid pleurisy (RA) due to dec transport of glc from blood to fluid
epmyema or TB due to increased utilization/consumption of glc
What is the mechanism of pleural fluid acidosis?
- acid production by pleural fluid cells or bacteria
- acid efflux from pleuritis or fibrosis (RA or malignancy)
**think esophageal rupture, infection, RA
What does a pleural fluid amylase/serum amylase >/= 1 suggest?
acute pancreatitis
pancreatic pseudocyts
**if amylase is salivary in origin = esophageal rupture
How is an effusion due to a ruptured ectopic pregnancy unique?
pleural fluid amylase/serum amylase >/= 1 suggest
T or F: a negative AFB rules out TB
false
What is the pathophys of a pneumothorax?
pleural is breached –> air enters pleural space (Patm >Pps) –> lung collapses inward towards mediastinum
What is the difference between primary and secondary pneumothorax?
primary = NO clinical lung disease present secondary = underlying clinical lung disease
What is thge classic clinical presentation of a primary spontaneous phneumothorax?
young, previously healthy make with acute onset of pleuritic chest pain and dyspnea
WHat are the possible mechanisms for a primary spontaneous pneumothorax?
- visceral pleural bleb: a collection of air within the layers of the visceral pleura (thin and easily ruptured?)
- bronchial obstruction with ball-valve mechanism (not sure how this works? i assume its a pressure thing)
What are the causes of a secondary spontaneous pneumothorax?
OLD: COPD, asthma, CF
ILD: sarcoid, lymphangioleiomyomatosis (LAM), pulmonary langerhans cell histiocytosis (PLCH)
infections: pneumocystis carinii in AIDS ots, TB
WHo gets a tension pneumothorax?
usually pts on MV (positive pressure ventilation)
*can occur with trauma
JUST NEED A ONE WAY VALVE, allowing air to enter the pleural space and preventing
the air from escaping naturally
What is a serious complication of a tension pneumothorax?
impaired venous return (compression of RA and SVC)
**clinically manifests as JVD
What are the 3 findings on a CXR that suggest a tension pneumothorax?
lung collape
contralateral mediastinal shift
depression of diaphragm
What are the clinical manifestations of a tension pneumothorax?
hypotension
hypoxemia
What is the Tx for a tension pneumothorax?
- emergent decompression with large bore needle
2. chest tube
