Pleural Effusion


yo M/F with PMH of , presenting with
 days constant/intermitent progressively worsening/improving

  • CC: SOB, pleuritic chest pain, cough, chest heaviness, hypoxia

  • PP: Dyspnea worse with exertion/lying flat, decreased exercise tolerance, pleuritic pain, fever/chills, productive cough, lower extremity edema, orthopnea, weight loss, night sweats

  • PN: No hemoptysis, no recent trauma, no unilateral leg swelling, no severe wheezing, no chest wall tenderness, no recent prolonged immobilization (if PE less likely)

  • Pertinent SHx: Tobacco use, heavy EtOH use, illicit drugs (especially IV drug use), occupational asbestos exposure, recent travel, TB exposure, malignancy history

  • Etiology: CHF, pneumonia/parapneumonic effusion, malignancy, PE, cirrhosis/hepatic hydrothorax, nephrotic syndrome, TB, autoimmune disease, pancreatitis

  • Initial DATA: CBC, CMP, BNP, troponin, lactate if septic, blood cultures if febrile, VBG/ABG if hypoxic, CXR, bedside POCUS, CT chest if unclear/concern for malignancy or PE, EKG,

  • Pending DATA:
    Thoracentesis studies (cell count, protein, LDH, glucose, pH, Gram stain/culture, cytology), Light’s criteria, pleural cultures, CT chest final read, echo if CHF suspected

  • MEDS:
    Oxygen PRN, IV diuretics if volume overload, empiric antibiotics if infectious concern, analgesics, anticoagulation if PE confirmed/strongly suspected

  • COURSE:
    Presented with dyspnea/chest discomfort found to have pleural effusion on imaging. Admitted for further evaluation of etiology, respiratory monitoring, and possible thoracentesis.

Plan

  • Diagnostic ± therapeutic thoracentesis

  • f/u thoracentesis results

  • Apply Light’s criteria to determine transudative vs exudative effusion

  • CXR/POCUS trend if clinically worsening

  • Treat underlying etiology (CHF, infection, malignancy, PE, etc.)

  • Diuresis if volume overloaded

  • Start/continue antibiotics if parapneumonic effusion suspected

  • Pulmonary consult if large/recurrent/loculated effusion

  • add Triglycerides: if suspected of chylothorax and Amylase if pancreatitis or esophageal rupture and ADA / TB studies for TB

Light’s Criteria

(Exudative if ANY are positive)

Pleural fluid is EXUDATIVE if ≥1 present:

  • Pleural protein / Serum protein > 0.5

  • Pleural LDH / Serum LDH > 0.6

  • Pleural LDH > 2/3 upper limit normal serum LDH

If none met → likely TRANSUDATIVE

Transudative Effusion — Main DDX

(Pressure/fluid balance problem)

  • CHF (most common)

  • Cirrhosis / hepatic hydrothorax

  • Nephrotic syndrome

  • Hypoalbuminemia/malnutrition

  • CKD/volume overload

  • Peritoneal dialysis

  • Constrictive pericarditis

Exudative Effusion — Main DDX

(Local inflammation/injury)

  • Pneumonia / parapneumonic effusion / empyema

  • Malignancy

  • Pulmonary embolism

  • TB

  • Pancreatitis

  • Rheumatoid arthritis / lupus

  • Hemothorax

  • Chylothorax

  • Esophageal rupture

  • Post-surgical/post-traumatic effusion

  • Drug-induced effusion

  • ARDS/viral infection

Pleural fluid tests and what they mean

  • Protein, LDH: Distinguish transudate vs exudate.

  • Glucose: Low in empyema, rheumatoid pleuritis, TB, malignancy.

  • pH: Low suggests complicated parapneumonic effusion/empyema; also seen in malignancy, TB, esophageal rupture.

  • Cell count and differential:

    • Neutrophils: acute infection, PE, pancreatitis.

    • Lymphocytes: TB, malignancy, chronic inflammation.

    • Eosinophils: air or blood in pleural space, pneumothorax/hemothorax, drug reaction.

  • Gram stain and culture: Identify bacterial infection.

  • Cytology: Looks for malignancy.

  • Hematocrit: Checks for hemothorax.

  • Triglycerides: Suggests chylothorax.

  • Amylase: Suggests pancreatitis or esophageal rupture.

  • ADA / TB studies: Support tuberculous pleuritis.

  • NT-proBNP: Supports heart failure, especially if the fluid is borderline exudative.