Ward Cases - Pneumonia, Pneumothorax, Effusion - PART 2 Flashcards
Once you determine via PA CXR that someone has an effusion, what needs to be done next?
How is this done?
Need to determine if it needs to be tapped
So, do a decubitus CXR
–if the effusion is 1+ cm, should tap it
Can also use US to determine size
–on US, fluid is black
Describe the pleural anatomy
The pleura is a serous membrane divided into visceral and parietal portions
A few mL of fluid is present normally, spread thinly into a several micron thick layer
The pleural space contains no air or gas
Lymphatic vessels in parietal pleura are in direct communication with pleural space via stomas
There are somatic sensory fibers in the parietal but not visceral pleura
What is the function of the pleura?
Couples lungs to the chest wall during respiration
Pleural effusion
- definition
- symptoms
Excess fluid in the pleural space
Asymptomatic OR Pain Dyspnea Cough Fever
Pleural effusion findings on P/E
Absent or diminished breath sounds
Dullness to percussion (shifting dullness)
Diminished or absent tactile fremitus over effusion
What is the difference in approach of a patient with a unilateral vs bilateral pleural effusions?
Nearly every patient with an unilateral pleural effusion requires a diagnostic thoracentesis
A patient with a bilateral pleural effusion may not require a thoracentesis
What is Light’s criteria?
Criteria to help determine if pleural effusion is an exudate or transudate
It is considered exudate if it meets at least one of the following three criteria
- pleural fluid protein / serum protein > 0.5
- pleural fluid LDH / serum LDH > 0.6
- pleura fluid LDH > 2/3 normal upper limit for serum
What is the significance of differentiation transudate from exudate?
It changes the Ddx
Transudate generally caused by SYSTEMIC processes that alter hydrostatic or oncotic pressures
Exudates are generally caused by LOCAL (less often systemic) factors that cause increased capillary permeability or decreased lymphatic drainage
Transudate DDx
Increased hydrostatic pressure
- -CHF
- -renal failure
Decreased oncotic pressure
- -cirrhosis
- -nephrotic syndrome
- -hypoalbuminemia (malnutrition, etc)
Exudate DDx
Parapneumoic effusion/empyema Neoplastic disease TB Collagen vascular disease (RA, SLE) PE Drug Rxn Post-surgical effusions - Dresslers Chylothorax Hemothorax
Clues that the exudate is an empyema
Pus, putrid odor, culture
Clues that the exudate is due to malignancy
Positive cytology
Clues that the exudate is due to lupus pleuritis
Positive LE cells
ANA > 1:160
Clues that the exudate is due to TB
AFB culture
Increased ADA
Clues that the exudate is due to RA
Low glucose
this can also indicates infection
