12/13 Pleural Diseases - Hussain Flashcards
pleura
types of pleura
mesothelial lining of each hemithorax
derived from embryonic coelomic lining
- visceral pleura: lung
- pareital pleura: wall
- costal
- diaphragmatic
- mediastinal
- cervical
pleural cavity & whats in it
pleural cavity is a potential space between visceral and pareital pleura
- holds a capillary layer of serous fluid produced by mesothelium → reduces friction and holds lung and thoracic wall together
- fluid is reabsorbed by the capillaries and lymphatics
pleural effusion
most common manifestation of pleural diseases
results from a disruption of the balance of hydrostatic and oncotic forces in visceral/parietal pleura as well as lymphatic drainage that keeps amt of fluid in pleural space constant
signs/sx:
- dyspnea
- cough
- chest pain
physical exam: usually dont manifest until > 300mL
- dull chest percussion
- decr tactile fremitus
- egophony
- decr breath sounds
- dyspnea related to distortion of diaphragm and chest wall during respiration (moreso than hypoxemia)
- dyspnea also caused by underlying intrinsic lung or heart disease, obstructing endobronchial lesions, diaphragmatic paralysis (esp after coronary artery bypass surgery)
quality of fluid from thoracentesis : likely etiology
frankly purulent : empyema
putrid : anaerobic empyema
milkly, opalescent : chylothorax, usually due to lymphatic obstruction
grossly bloody : need to do a spun hematocrit
- over 50% of normal → hemothorax
two types of pleural effusion
1. transudative pleural effusion
- imbalance between formation and absorption of fluid
- pleural fluid shows normal contents (pH, glucose, LDH, protein)
- usually due to:
- CHF
- hepatic hydrothorax
- chronic renal diseases
2. exudative pleural effusion
- alteration of fluid formation process in response to local or systemic inflammatory process
- pleural fluid contains contents indicative of infl rxn (WBC, LDH, protein)
- usually due to:
- infection and malignancy
how to differentiate between transudative and exudative pleural effusion
LIGHT’s criteria
exudative has one or more of the following:
- protein: pleural effusion/serum > 0.5
- LDH: pleural effusion/serum > 0.6
- LDH: more than 2/3 of normal serum value
what about cases where something is almost certainly a transudate but comes up with exudative props? (ex. water pill)
- use serum-fluid gradient of albumin, protein
- look at pleural fluid cholesterol
- look at bilirubin
chylothorax
lymphatic fluid (chyle) leaks into pleural space due to leakage from thoracic duct
- can be due to lymphoma and trauma
- look for triglycerides (>125), usually in form of chylomicrons
treatment
- drainage
- pleural-peritoneal shunt
- pleurodesis
- omitting FAs
- octreotide
pneumothorax
abnormal collection of air in the pleural space
three types:
- primary: occurs spontaneously, no underlying lung disease
- secondary: underlying lung disease present
- tension pneumothorax: collapse resulting in hemodynamic compromise - MEDICAL EMERGENCY
possible causes:
- communication between alveolar space and pleural space
- communication between atmosphere and pleural space
- production of gas in pleural space
primary pneumothorax
- usually occur at rest
- acute onset chest pain and dyspnea
- pain generally resolves in 24hr
physical exam
- decr chest excursion
- diminished breath sounds
- hyperresonant percussion
- decr/absent tactile fremitus
management
- thoracentesis
- tube thoracostomy
- pleurodesis, pleural sclerosis
- surgery
- alt diet (for chylothorax)
pleural cancers
metastatic carcinomas
- pleural metastasis is common in pts with malignant tumors
- lung and breast cancer accounts for 2/3
- malignant pleural effusion has a poor prognosis
- median survival 3-12mo
pleural cancers
mesothelioma
- rare neoplasm arising form mesothelial surfaces of pleural cavity
- assoc with asbestos, smoking
- poor prognosis
- 4-13 months untreated
- 6-18 months treated
