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NEJM Video Guide


  • New pleural effusion that has no obvious explanation (not attributed to HF alone) or concern for pleural space infection

  • Any respiratory symptoms that would positively respond to large volume thoracentesis (>1L)


  • Skin infection at needle insertion site

  • Large-volume thoracentesis in hepatic hydrothorax (tends to reaccumulate). Suspected unexpandable lung

  • Common risks (> 5%): coughing, fainting, PTX

  • Rare risks (< 1%): hemothorax, re-expansion pulmonary edema, liver/spleen puncture

Pre-procedural considerations

  • Bleeding risk guidelines: Plts > 50k, INR < 2 (risk/benefit evaluation outside these)

  • If loculations present on US, high risk, or any question about indication, refer to Pulm

  • Labs (order before so nurse can print labels): cell count w/diff; BF culture, BF & serum LDH, BF & serum total protein; BF & serum Hct if bloody; cytology if c/f malignancy; consider triglycerides if concerned for chylothorax

Procedural considerations

  • US Probe: Cardiac (or Linear) to identify safe pocket (>2 cm) between lung and diaphragm (ask Interventional Pulm or IR if sample is needed of a smaller pocket)

  • Kit: 6Fr Safe-T-Centesis kit

  • Upright position is typically preferred; lateral to mid-scap/mid-ax. If patient unable to sit upright, refer to procedure team vs pulmonology

  • Effusion size: if unable to tap above 9th rib, too small; CXR with costophrenic angle blunting should correlate to ~250-500mL

  • Insert needle superior to rib to avoid neurovascular bundle (bundles run below)

  • Stop if pt has any new/increased chest discomfort, aggressive unremitting cough, frank purulence or air on aspiration, lightheadedness, hypotension, or vagal response

  • Stop fluid removal after 1.5 L of chronic pleural effusion to reduce re-expansion pulmonary edema

Post-procedural considerations

  • If needing cytology, send at least 60 – 100cc

  • Bleeding complication: STAT page Thoracic Surgery

  • PTX: if pt stable & asymptomatic, supplemental O2 and repeat CXR in 4hrs; if unstable/symptomatic STAT page to Thoracic Surgery

  • Re-expansion pulmonary edema: persistent cough, frothy sputum. Diffuse GGO on side of thoracentesis. Supportive management (oxygen, monitor); most resolve in 24-48 hrs. If respiratory distress progresses, may need mechanical ventilation

  • Documentation: Effusion US characteristics (anechoic, layering debris, septations), reason for ending procedure (stopped early due to chest discomfort, complication vs tapped dry), presence of lung sliding, if more than scant residual effusion remains post-procedure

  • A routine chest radiograph after thoracentesis is no longer indicated for most asymptomatic, non-ventilated patients. Check lung slide with US in 2D and M-mode