Pulmonary Flashcards
Normal pleural fluid function and composition
Normal function: provide smooth surface that reduces friction as pleura (visceral and parietal) move across each other
Normal composition: 1-10mL. Ultrafiltrate of plasma. NO protein (<1-2g), almost no WBC (<1,000), glucose similar to plasma and LDH < 50% of plasma
Factors affecting interstitial fluid formation
Force #1: Hydrostatic pressure (pushing force)
Force #2: Oncotic pressure (pulling force)
Pleural Effusion definition
Abnormally large collection of fluid in the pleural cavity - usually an indicator of a pathologic process/manifestation of an underlying disease
Clinical presentation pleural effusion
Often ASYMPTOMATIC
- SOB
- Cough
- Pleuritic chest pain
If caused by CHF, then LE edema in combo with above
IF caused by Tb/CA then night sweats, fever, weight loss in combo with above
PE Findings pleural effusion
Decreased tactile fremitus Decreased breath sounds Dullness to percussion Egophany (E --> A) \+/- pleural friction rub
Exudative effusion vs transudative effusion
Exudative: 2/2 increased vascular permeability (infection (acute-empyema, chronic-Tb), inflammation (SLE/RA), malignancy) - contains increased plasma proteins, WBCs, platelets
Transudative: Due to increased hydrostatic pressure (CHF) or decreased oncotic pressure (nephrotic syndrome, liver cirrhosis/failure, atelectasis
Light’s Criteria
Fluid is exudative if > 1 of the following criteria are met:
- Ratio of pleural fluid LDH: serum LDH >0.6
- Pleural fluid LDH > 2/3 upper limit of reference range for serum LDH
- Ratio of pleural fluid protein : serum protein >0.5
4 Types of fluid that accumulate in pleural space
- Serous fluid = hydrothorax
- Chyle = chylothorax (lymph fluid w/ TB & fat)
- Blood = hemothorax
- Pus = empyema (infected pleural cavity)
Pleural fluid analysis (3 items always analyzed)
- Protein
- LDH
- Specific gravity (<1.015 = transudative)
MCC Exudative effusion
Malignancy
MCC Transudative effusion
CHF
Empyema definition and etiology
Infection of the pleural space causing a pus-filled pleural effusion
Etiology
- Complication of PNA where bac escape to pleural space
- Penetrating trauma
- Complication of surgery, thoracentesis, chest tube
Fluid analysis of empyema
Grossly purulent fluid (pus-like) pH level <7.2 WBC >50,000 Glucose <60mg/dL LDH > 1,000 IU/mL
Treatment empyema
DRAINAGE (thoracentesis) & ABX vs…
VATs thoracoscopy with tube drainage vs…
Clagett window (open drainage of empyema cavity)
Pathophysiology, etiology, treatmentof malignancy pleural effusion
BFTP: Malignancy = MCC exudative pleural effusion
Patho: CA = inc capillary permeability, disruption of capillary endothelium, impaired lymphatic drainage, direct invasion of pleural space by tumor & malnourishment (hypoalbuminemia)
Etio: Primary sites of MPE tumors - lung, lymphoma, breasts, ovary
Tx: Thoracentesis & tx of malignancy (radiation, chemo)
Tx options for repeat pleural effusions (2)
- Pleurodesis - artificially obliterate pleural space via chamical sclerosant (Talc, Doxy) or pleural abrasion (mechanical)
- Indwelling pleural catheters - small tube is inserted to drain fluid from around lungs - denver vs bard - pros = less pain, shorter hospital stay than pleurodesis
Diagnosis of pleural effusion
- CXR - can see p. effusions >150 ml as blunting of the lateral costophrenic sulcus, 500 cc blunts the costophrenic angles on PA view (called the + menisci sign) - lateral
- CT - can detect v. sm effusions that can easily be missed by CXR
- Thoracentesis (GOLD STANDARD) - both therapeutic and diagnostic - done with all effusions of unknown causes
PTX definition & mechanism
Presence of air or gas in the pleural cavity.
Air can enter thru a communication from the chest wall (trauma)
Or more commonly a communication thru the lung parenchyma across the visceral pleura
Primary spontaneous pneumothorax
Occur in people WITHOUT underlying lung disease - caused by ruptured pulmonary blebs (congenital)
Occurs in pt ages 18-40 YO, male, tall, thin & smokers
Secondary spontaneous pneumothorax
Secondary spontaneous pneumothorax occurs in patients WITH underlying lung disease
COPD = MCC, others = severe asthma, lung infections, CF, sarcoidosis, marfan’s, catamenial ptx (endometriosis in lung pleura)
Traumatic pneumothorax
MC due to penetration of sharp bony points at a new rib fracture 2/2 trauma (blunt or penetrating)
Iatrogenic 2/2 central venous catheter placement, mechanical ventilation, biopsy of lung, thoracentesis
Turns into a tension pneumothorax commonly
Tension pneumothorax etiology
Progressive build up of air within pleural space 2/2 lung laceration via trauma or iatrogenic cause
Air pushes mediastinum to the OPPOSITE side & obstructs venous return to the heart causing cardiac arrest
Clinical presentation tension PTX (5)
Tachycardia > 135 Hypotension Chest pain Diaphoresis Cyanotic
PE Findings tension PTX
Deviation of trachea to contralateral side (CXR)
Hyper-expanded chest
Distended neck veins (venous return obstructed so backs up into jugular veins)
Absent breath sounds (chest cavity filled w/ air not lung tissue)
