Cause of PEEVO | Fluid type | Patient characteristics | Pleural fluid characteristics | Diagnostic test |
Transudative PEEVO | ||||
PDAPE | Peritoneal dialysate | Unilateral effusion in patient undergoing peritoneal dialysis (fluid migrates across the diaphragm) | Clear fluid, transudate with very low protein | Glucose = 200 to 2000 mg/dL, PF/S glucose >1 |
Urinothorax | Urine | Ipsilateral effusion in a patient with obstructive uropathy or iatrogenic/traumatic injury to GU tract Urinoma may be present on imaging | Serous, transudate with very low protein (<1 mg/dL), pH <7.40 | PF/S creatinine >1 (supportive) >1.7 (diagnostic) |
EVM of CVC | Intravenous fluid | Ipsilateral effusion in a patient with newly placed CVC (catheter migrates through the posterior venous wall and mediastinal pleura) | Serosanguinous (if mixed with blood) transudate with very low protein, IV fluid content* | Content reflective of infusate (eg, high glucose if dextrose) |
VP or VPL shunt DPF | CSF | Effusion in patient with VP or VPL shunt Patient with an effusion who has a spinal cord tumor or is status post a neurosurgical procedure (eg, laminectomy, discectomy) or thoracic surgery (eg, thoracotomy or thoracoscopy) | "Clear water," transudate with very low protein (<1 mg/dL) | Beta2 transferrin present |
Glycinothorax | Irrigation fluid rich in glycine | Effusion in a patient undergoing irrigation for transurethral bladder surgery | Clear fluid, transudate | PF/S glycine 300:1 or higher |
Hepatic hydrothorax | Ascites | Effusion in a patient with portal hypertension | Clear transudate similar to ascites (unless infected) | Clinical diagnosis of exclusion |
Exudative PEEVO | ||||
Esophageal or gastric perforation | Infected or esophageal/gastric contents | Unilateral, often left-sided effusion in a patient with injury or pathology of the esophagus or stomach | Purulent, foul odor, exudate with high PMN, LDH >1000 IU/L, Ph5-7 | PF/S amylase >1 Salivary isoenzyme Food particles |
Enteral feeding tube migration | Enteral formula | Patient with effusion (often left-sided) after misplacement of feeding tube (penetration of esophagus or tracheobronchial tree) | Milky fluid, exudate | TG >110 mg/dL [1.24 mmol/L], PF/S glucose >1 |
Pancreaticopleural fistula | Pancreatic fluid | Right-sided effusion in patient with chronic pancreatitis or pseudocyst | Turbid yellow, exudate | Amylase >100,000 IU/L (pancreatic isoenzyme) |
Bilothorax | Bile | Right-sided effusion following injury to the biliary tree, or from biliary tract obstruction or from parasitic infection of liver, or sub diaphragmatic abscess | Green and turbid, exudate with signs of infection (eg, high white blood cell count, high percentage of neutrophil, high lactate dehydrogenase, pH <7.2, low glucose) | PF/S bilirubin >1 (organisms may be present) |
Chylothorax | Chyle (lymphatic fluid) | Effusion in patients with lymphatic pathology (eg, tumors, trauma, LAM) | Milky fluid, exudate | TG >110 mg/dL [1.24 mmol/L] and/or detection of chylomicrons |
Cholesterol effusion | Cholesterol | Effusion in a patient with tuberculosis or rheumatoid arthritis | Milky fluid exudate | Pleural fluid cholesterol level ≥200 mg/dL [≥5.18 mmol/L], a cholesterol to triglyceride ratio >1 in the pleural fluid, chylomicrons absent |
PEEVO: pleural effusion of extra-vascular origin; PDAPE: peritoneal dialysis-associated pleural effusion; PF/S: pleural fluid to serum ratio; EVM: extravascular migration; CVC: central venous catheter; VP: ventriculoperitoneal; VPL: ventriculopleural; CSF: cerebrospinal fluid; DPF: duropleural fistula; PMN: polymorphonuclear neutrophil; LDH: lactate dehydrogenase; TG: triglyceride; LAM: lymphangioleiomyomatosis.
* Exception is when total parenteral nutrition or lipids are being infused, in which case protein is present and fluid will be milky, respectively.