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)
Treatment tension pneumothorax
Needle decompression - 2nd intercostal space, mid-clavicular line right ABOVE the third rib (2nd interspace)
Signs and symptoms of PTX
Symptoms:
SOB
Pleuritic chest pain
Shoulder pain
Signs:
Hyper-resonance to percussion (hollow air)
Decreased tactile fremitus
Decreased breath sounds
Treatment small pneumothorax
(<10-15% decrease) - conservative management = observe for 6 hours, repeat CXR (make sure not increasing) & supplemental 100% oxygen (inc rate of resorption). Follow up in 24 hours - often spontaneous resolves w/in 10 days
Chest decompression via chest tube or pigtail catheter (if getting bigger & bigger (<30%) on serial CXR then we need to intervene
Treatment recurrent PTX
Pleurodesis or surgery (VAT blebectomy)
Foreign body aspiration epidemiology & MC items aspirated
80% of FBA occur in children < 3 TO - infants & toddlers aspirate on food items (nuts = MC) & older children aspirate on non-food items
Most fatal foreign body aspirations
Marbles, toy balloons, rubber gloves (round, smooth, slipper surface = BAD)
MC location FBA
Right main bronchus
Symptoms of foreign body aspiration
Sudden onset wheezing or severe respiratory distress
Cyanosis
Change in mental status
Hoarseness, SOB, wheezing
CXR FBA
Only helpful if object aspirated is radiopaque
Lower airway FBA causes hyperinflated lungs proximal to the FB, atelectasis (collapsed lung) distal to the FB, and later PNA (collapsed lung = nidus for bacterial infection)
FBA treatment
Detailed clinical history and physical exam is the main determinant of whether bronchoscopy is needed
Rigid or flexible bronchoscopy is almost always successful in FB removal (95%)
Pulmonary embolism definition & etiology
Thrombus in the pulmonary artery or its branches
Not a disease itself but a complication of a DVT (95% of PEs arise from DVTs in lower extremities above the knee (iliofemoral or pelvis) - other causes = fat emboli from long bone fracture or air emboli from central line
History questions pulmonary embolism
VIrchow’s triad - ask about:
- Stasis (sedentary, long travel, recent surgery or hospital stay (immobilized in hospital bed)
- Hyper-coagulability (pregnancy, cancer, family hx)
- Endothelial trauma (surgery, trauma)
Signs & symptoms PE
SOB, tachypnea, tachycardia, pleuritic chest pain
Also: Cough, hemoptysis, +homan’s sign (pain w/ dorsiflexion)
Signs & symptoms of massive PE
Syncope, hypotension, PEA
Diagnosis PE
CTA (pulmonary angiography) = GOLD STANDARD
Helical CT scan = best initial test for suspected PE (most sensitive for proximal emboli)
V/Q scan - may be used if CT scan is contraindicated (pregnancy, CrCl < 30)
DVT - 70% of pt w/ PE will be + for LE DVT - can miss pelvic DVTs - serial US may be performed to increase diagnostic specificity
Ancillary evaluation tests:
CXR is usually normal - can have pleural effusion, atelectasis or abrupt cutoff of vessels - classic but rare signs can have Westermark’s sign (avascularity distal to embolus) or Hampton’s hump (wedge-shaped infiltrate (represents infarction)
EKG: Sinus tach w/ NSSTTWC - S1Q3T3 = classic but rare (represents cor pulmonale/right heart strain)
ABG: Initial respiratory alkalosis 2/2
