pleural effusions + pneumothorax Flashcards
pleural effusion def and list the four pathophysiologic processes
Definition: Abnormal accumulation of fluid in the pleural space (5-15 mL of fluid in pleural space)
1) Transudates: normal capillary function
2) exudtes: abnormal capillary permeability
3) empyema: infection in pleural space
4) hemothorax: blood in pleural space
transudate pathophys + causes
- Normal Capillary Function
Due to:
-increased HYDROSTATIC pressure (pushes fluid out) OR - decreased ONCOTIC (cannot hold onto fluid)
Causes:
- CHF: (MC) - bilateral
- Cirrhosis: low protein
- Nephrotic Syndrome: low proteins -> spills out
others:
-Acute atelectasis
-Constrictive pericarditis
-PE
-Superior vena cava obs
exudate causes
Due to ABNORMAL capillary permeability
- Decreased lymphatic clearance = fluid accumulation
Causes
- Pneumonia *
- Cancer *
- PE
- infection
Others:
-Post MI
-Chronic atelectasis
-Asbestos
-Sarcoid-rare
PE of pleural effusion: small vs large vs massive
-Dyspnea, cough, or chest pain- Small less symptomatic
PE:
Small: none
Larger:
- dullness to percussion
- diminished or absent breath sounds over effusion
Massive:
- may have contralateral shift of trachea (ddx tension pneumothorax)
- bulging of the intercostal spaces**
what is the gold standard diagnostic test for pleural effusions?
Gold Standard = Diagnostic Thoracentesis
- Indicated with new pleural effusion of no known cause
- Can collect sample for laboratory analysis: Transudative vs Exudative
-1. Visualization of fluid
-2. Send to lab:
-Cell count and cell differential, pH, protein, LDH, glucose -> determines Transudate vs exudate
-Additional tests in selected patients: amylase, cholesterol, triglycerides, N-terminal pro-brain natriuretic peptide (NT-proBNP), creatinine, adenosine deaminase (ADA), gram and acid-fast bacillus (AFB) stain, bacterial and AFB culture, and cytology
pleural fluid analysis
Malignancy= positive cytology
Empyema= Pus, positive culture
Chylothorax= triglycerides
Tuberculous- Positive AFB stain
hemorrhagic vs hemothorax
Hemorrhagic: MIX of blood and pleural fluid
-10,000 rbc/ml to create blood-tinged fluid (dont need to know #)
Hemothorax: GROSSLY blood in pleural space
- 100,000 rbc /ml create grossly bloody pleural fluid
-straw colored
-blood stained
-purulent
-chylous
hemothorax ratio
Gross blood in pleural space:
- [Pleural Fluid Hct] : [Serum Hct] > 1:2
Appearance:
-straw colored
-blood stained
-purulent
-chylous
exudate lights criteria rule***
-Effusion that has ONE OR MORE of the following is exudate:
*Pleural fluid protein/serum protein ratio greater than 0.5
*Pleural fluid LDH/serum LDH ratio greater than 0.6
*Pleural fluid LDH greater than two-thirds the upper limits of the laboratory’s normal serum LDH
“these are saying that there is:
HIGH proteins - capilllary permeability increased
HIGH LDH - indicates exudative”
transudates def
-Transudates have NONE of mentioned exudate features/criteria
-Occur in setting of NORMAL CAPILLARY integrity and ABSENCE of local pleural disease
Distinguishing laboratory findings include:
-Glucose = serum glucose
-pH between 7.40 -7.55 (nl 7.6)
-< 1,000 wbc/mcL with a predominance of MONONUCLEAR cells
“basically this is a systemic issue that causes altered hydrostatic and oncotic pressures and NOT FROM INFECTION (exudates)”
Exudates:
- lower glucose: bacteria is consuming glucose
- ph is LOWER due to infection
- HIGH WBC = infection
Elevated pleural amylase: evidence of what
Elevated pleural amylase:
-Pancreatitis, pancreatic pseudocyst
-Adenocarcinoma of pancreas
-Esophageal rupture
Other features of pleural effusion- cytology
can use cytology: assess for malignancy
imaging: effusion
Standard upright CXR:
-must have 75–200 mL to be visible in costophrenic angle
May appear loculated (~mass/pseudotumor) if there are pleural adhesions:
-Round/oval fluid collections in fissures resembling intraparenchymal masses (pseudotumors)
Chest CT scans: more sensitive!!
- Can identify pleural effusions >15 mL
transudative treatment
1: treat underlying condition - will just fill again if not
2: Therapeutic thoracentesis for significant dyspnea
-Repeat again and reassess dx
3: if refractory after repeat
-Pleurodesis- irritant into the space- obliterates the space so no fluid can fill
-Indwelling pleural catheter- drain at home
exudate malignant treatment: what are the MC cancers, acute tx vs long term
Malignant Pleural Effusion:
-Most common: lung and breast cancer
Acute tx:
- repeated thoracocentesis
- chest tube
Long-term if needed:
-Pleurodesis
-Indwelling pleural catheter (eg, Pleurex) for home drainage
parapneumonic pleural effusion categories
Divided into 3 categories:
-Simple or uncomplicated
-Complicated
-Empyema
+/- loculation often in empyema or complicated
Exudates accompany approximately ___% of bacterial pneumonias. Parapneumonic pleural effusions
40%
uncomplicated parapneumonic effusions tx
-Free-flowing sterile exudates of modest size that resolve quickly with antibiotic treatment of pneumonia
Tx: NONE
- no drainage
- just do normal abx for pneumonia
empyema
Gross infection of pleural space indicated by positive Gram stain or culture
Tx:
- ALWAYS DO drainage
- antibiotics for effusion
complicated parapneumonic effusions tx
Requires difficult management decisions
-Larger than simple parapneumonic effusions and show more evidence of inflammatory stimuli
- Demonstrate inflammatory processes: Low glucose level, low pH, or evidence of loculation
Tx - Tube thoracostomy (chest tube for drainage) if:
- glu is < 60 mg/dL
- pH is < 7.3
-clinical decision based on provider
Loculation: what type of effusions is this a complication and what is tx
Empyema or complicated parapneumonic effusions
Tx:
-Intrapleural injection of fibrinolytic agents: (-kinase)
-Streptokinase, 250,000 units
-Urokinase, 100,000 units
-break up the loculation
Definition:
-fomration of compartmentalization within the pleural space due to ahdesions
hemothorax tx
Small: close observation
ALL other cases: IMMEDIATE insertion of a large chest tube (tube thoracostomy )
-Controls hemorrhage
-Removes clot
-Treats complications
-drained
pneumothorax classification
(Non-Traumatic) Spontaneous pneumothorax:
-Primary: Occurs in absence of underlying lung disease
-Secondary: Complication of preexisting pulmonary disease (COPD bulla)
Traumatic pneumothorax:
-Results from penetrating or blunt trauma
-iatrogenic
Tension:
- one way valve into pleural space
primary pneumothorax causes
Occurs without a known cause:
- often tall, thin, young males -> usually result from the rupture of small, air-filled sacs on the lung surface (BLEBS or bullae).
-drug use
-increased transpulmonary pressure -> valsava maneuver, diving, military, flying
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