Lec 22 Pleural Diseases Flashcards
What is blood supply to pleura?
parietal = intercostal arteries visceral = bronchial arteires
WHat is drainage of parietal pleura?
systemic veins
What is drainage of visceral pleura?
pulmonary veins
WHat is lymphatic drainage of parietal pleura?
internal mammary chain and internal intercostal chain
What is lymphatic drainage of visceral pleura?
hilar and middle mediastinal lymph nodes
Which part of pleura is normally responsible for pleural fluid formation and absorption?
parietal pleura!
What is starling equation for pleura?
fluid movement = L [(Pcap - Ppleura) - o(oncoticPcap - oncoticPpleura)]
What are pleural stomata?
big holes in parietal pleura = look liek microvilli in intestine
designed for moving fluid around + can take up large particles
What are the 2 causes of pleural effusion?
altered permeability of pleural membranes = EXUDATE
altered driving P = TRANSUDATE
What things typically cause exudative pleural effusion?
inflammation or tissue disruption
WHat things typically cause transudative pleural effusion?
fluid avid states –> CHF, cirrhosis, nephrotic syndrome
== not the lung’s fault
How do you detect effusions on physical exam?
decreased breath sounds and fremitus; dullness to percussion
How do you detect effusions on chest radiograph?
200-500 mL of fluid needed to blunt lateral costophrenic angle
When are two situations when you DONT tap pleural effusion?
- less than 10 mm of free-flowing fluid on lateral decubitus film
- CHF w/ improvement with treatment
What is technique for thoracocentesis?
- insert one interspace below loss of fremitus/dullness to percussion
- pt upright not leanding forward
- insert over rib [b/c vessel/nerve below]
What is light’s criteria?
if any criteria met = exudate
if none met = transudate
- pleural fluid/serum protein ration > 0.5
- pleural fluid/serum LDH ratio > 0.6
- pleural fluid LDH > 2/3 upper limit of normal
What are some things that cause transudative effusions?
- CHF
- nephrotic syndrome
- hypoalbuminemia
What are some findings in transudative pleural effusion?
- increased hydrostatic P
- decreased plasma oncotic P
- movement of transudative abdominal fluid [ascites]
How does pleural effusion form in CHF?
high PCWP –> fluid leaks into interstitium of lung and subsequently pleural space
What is hepatic hydrothorax?
- pressure in abdomen is positive; pleura is negative
fluid may move north if there is a connection
R more than L
fluid is transudate
due to ascites
How do you treat hepatic hydrothorax?
treat the ascites –> diuretics, reduced portal pressure
What are some causes of exudative effusions?
- infectious
- malifnant
- PE
- asbestos
- chylothorax
What is a parapneumonic effusion?
effusion around the time of pneumonia
What are 3 types of parapneumonic effuson?
- simple
- complicated
- empyema
What is complicated parapneumonic effusion?
loculated
pH < 7.2
LDH > 1000
What is empyema?
parapneumonic effusion that contains organisms or has gross appearance of pus
What is possible complication of empyema/complicated parapnuemonic effusions if left undrained?
- fibrothorax
- septic shock
What is TB pleuritis?
- subpleural focus of TB ruptures into pleural space 6-12 wks after primary infection or reactivation
TB antigens in pleural space –> acute hypersensitivity rxn w/ exudative pleural effusion
If not treated what happens in TB pleuritis?
- generally resolves over wks
- 65% go on to develop active pulm TB
What causes malignant pleural effusion?
- tumor implanted on pleural surface from embolus or direct extension lung/breast
- lymphatic obstruction by tumor prevents fluid reabsorption
What are symptoms/signs of pleural effusion?
- dyspnea
- pleuritic chest pain
- fever
- dull to percussion
- decreased breath sounds
- pleural friction rub
What do you see on xray in pt with pleural effusion?
- blunted costophrenic angle
What is a loculated pleural effusion?
effusion that is not really moving around = can see thick visceral pleura on inside
What defines hemothorax?
pleural fluid with Hct > 50% of serum Hct
What is a pneumothorax?
air in pleural space
What are two types of pleural effusion? etiologies?
entry from parietal pleura = trauama or iatrogenic
entry from visceral pleura = rupture lung cyst; complication of mechanical ventilation; necrosis due to tumor, infection
WHat is a spontaneous pneumothorax?
sudden onset pleuritic chest pain w/ dyspnea
Who gets primary pneumothorax?
tall, male, thin smoker
w/ asymptomatic subpleural blebs
What are some diseases associated w/ spontaneous pneumothorax?
emphysema, PCP, CF, abscess
What is effect of tension pneumothorax?
- collapsed lung
- decrease venous return
- displaced mediastinum to opposite side of chest
- cardiovascular collapase
