Indications for Thoracentesis

1. Indications for Thoracentesis

2. Objectives • Know when to consider a thoracentesis • Know how to evaluate if safe to perform thoracentesis • Know when to consult specialists • Quick review of pathophysiology of effusions • Know how to analyze the fluid obtained • Know when pleural fluid results suggest a need for a chest tube • Summary

3. Indications for thoracentesis • Symptom relief • Dyspnea • Unstable pulmonary mechanics, gas exchange • Diagnostic purposes • When the cause of the effusion is unclear

4. Pre-procedure check list • Normal hemostasis • Effusions with thickness > 1 cm on lateral decubitus film • Ultrasound evaluation of the pleural space • Weigh risks and benefits of procedure • 4 studies between 1983 and 1994 looking at complications of thoracentesis reported rates of pneumothorax between 11 to 19%. • 2 studies in 2009 and 2010 specifically addressing use of ultrasound for fluid location show risk of pneumothorax declines to 0.6 to 1.1%. Good training and experience matter. • Risks for complications: large volume thoracentesis, COPD

5. When to consult with specialists • Consult Pulmonary Team when: • If overall clinical situation warrants pulmonary specialty assist • If pre-procedure evaluation indicates may be difficult thoracentesis to perform • If medical team lacking a member who feels confident performing the procedure • Pulmonary team strongly encourages consults with them prior to requesting Intervention Radiology to perform the procedure

6. Etiology of a Pleural Effusion Pleural fluid accumulates when formation exceeds absorption Normally: Fluid enters pleural space from parietal pleura capillaries and is drained via the lymphatics in parietal pleura. Fluid can also come from: interstitial spaces of lung via visceral pleura peritoneal cavity via small holes in diaphragm.

7. Diagnostic Approach to Pleural Effusions • Transudative effusions occur with either increased mean capillary pressure or decreased oncotic pressure • Cirrhosis Left ventricular failure Nephrotic syndrome • SVC obstruction Myxedema Peritoneal dialysis PE • Exudative effusions occur with damage or disruption of the normal pleural membranes or vasculature occurs, leading to increased capillary permeability or decreased lymphatic drainage. • Infectious diseases • Malignancy • Pulmonary embolism • Collagen vascular diseases: RA, SLE, Wegener’s g.,Sjogren’s • Drug-induced: nitrofurantoin, amiodarone, bromocriptine

8. Differentiation between exudative and transudative Exudative effusions meet at least one of the following criteria, transudative meet none: Light’s criteria: • Pleural fluid protein/serum protein>0.5 • Pleural fluid LDH/serum LDH>0.6 • Pleural fluid LDH more than 2/3 normal upper limit for serum 2 Test Rule: • Pleural fluid cholesterol > 45 mg/dL • Pleural fluid LDH > .45 upper limit normal serum LDH 3 Test Rule: as above 2 Test, but add: • Pleural fluid protein > 2.9 g/dL • Note if fluid exudative, need description of fluid, pH, glucose level, differential cell count, microbiologic studies, and cytology

9. Other diagnostic pleural fluid tests • Glucose < 60 mg/dL • Malignancy • Bacterial infections • Rheumatoid pleuritis • Amylase • Acute pancreatitis • Esophageal rupture • Lung carcinoma • Triglycerides > 110 mg/dL, milky appearance • Chylothorax , usually from trauma or mediastinal tumors • Cell count predominantly neutrophils in febrile pt with normal pulmonary parenchyma • Intraabdominal abscess

10. Other diagnostic pleural fluid tests • Bloody pleural fluid • Pleural hematocrit/serum hematocrit > 0.5 = hemothorax • Usually result of trauma or tumor, or infarction • Tuberculous effusions • Exudative with predominantly small lymphocytes • Adenosine deaminase > 40 IU/L • Interferon gamma > 140 pg/mL, positive PCR for TB DNA • Fluid culture, needle biopsy of pleura • pH < 7.3 • Empyema malignancy esophageal rupture • Collagen vascular disease TB

11. Factors suggestive of need for chest tube (placed in increasing order of importance) • Loculated pleural fluid • Pleural fluid pH < 7.20 • Pleural fluid glucose < 60 mg/dL • Chylothorax • Hemothorax • Positive Gram stain or culture of pleural fluid • Presence of gross pus in pleural space

12. Summary • Indications: symptom relief, stabilization, and diagnostic • Weigh risks and benefits • Pre-procedure, double check safety: hemostasis, fluid quantity and location • Call Pulmonary consult if: • Need pulmonary input in the case • Pre-procedure check indicates a difficult thoracentesis • Team lacking a member with good experience and confidence in performing the thoracentesis • Recommend calling Pulmonary prior Interventional Radiology

13. Resources • Reducing iatrogenic risk in thoracentesis: establishing best practice via experiential training in a zero-risk environment. Duncan DR, Morgenthaler TI, Ryu JH, Daniels Chest. 2009;135(5): 1315 2. Pneumothorax following thoracentesis: a systematic review and meta-analysis. Gordon CE, Feller-Kopman D, Balk EM, Smetana GW Arch Intern Med. 2010;170(4):332 • Complications associated with thoracentesis. Seneff MG, Corwin RW, Gold LH Chest 1986; 90:97-100 • Thoracentesis: complicatons, patient experience and diagnostic value. Collins TR, Sahn SA. Am Review Respiratory Disease 1983; 127:A114 • Harrison’s Principles of Internal Medicine, 17th edition. Fauci, Braunwald, Kasper, Hauser, Longo, Jameson, Loscalzo. 6. UpToDate online. www.uptodate.com.