Thoracentesis/Pleurocentesis

• Definition: Percutaneous procedure to remove pleural fluid.
• Use of either needle (smaller volumes, <30 mL), needle over catheter, or small-bore catheter.
• Can be performed at bedside in emergency departments.

Indications

Diagnostic

• Presentation of new pleural effusion – determining cause.
• Exceptions:
  • Small volume pleural effusion with clear diagnosis – eg. viral pleurisy,
  • Clinical CHF with typical features.
    • Atypical Features suggest alternate diagnosis:
      • bilateral effusions that are very different in size – especially when left >> right
      • Features of pleurisy
      • Fever
      • Features indicative of infection or cancer
      • Echocardiogram inconsistent with CHF
      • Poor improvement of effusion with effective CHF therapy.

Therapeutic

• Symptom relief, eg. dyspnea.
• Complicated pleural effusions, eg. loculations in a parapneumonic pleural effusion.
• Pleural conditions that can potentially lead to pleural thickening and restrictive functional impairment, eg. effusions as result of post-primary or reactivation tuberculosis, hemothorax.
• Multiple factors determine duration of drainage.
  • Size of effusion, locations, whether complete drainage is needed, institutional factors, etc.

Contraindications

• Small volume of pleural fluid.
• Skin infection at site.
• Bleeding diathesis.
  • limited data on safety of thoracentesis when taking anticoagulants, coagulopathy, or thrombocytopenia.
    • Individualized approach needed.
    • Interventional Radiology (IR) Thoracentesis (Society of Interventional Radiology Consensus Guidelines in Image-Guided Interventions):
      • Thoracentesis considered low risk bleeding procedure in IR.
        • If patient has low bleeding risk, generally safe to continue current anticoagulation. Please see guidelines in reference to all specific anticoagulants (and antiplatelets).
    • Patel et al:
      • Retrospective, Single Center (low-quality study).
      • Conclusion: Overall risk of major bleed with patients taking DOAC and/or clopidogrel in Ultrasound-Guided Thoracentesis is very low.

Mechanical ventilation is not considered a contraindication to thoracentesis (PEEP doesn’t increase risk of pneumothorax).

Should I Refer to Interventional Radiology?

• Consider if difficult patient, patient with limiting comorbidities, provider lacks skills, or lack of adequate equipment/bedside ultrasound.
• Kozmic et al: Bedside thoracentesis with portable ultrasound is as safe as IR procedures and less costly.

Equipment

• Sterile gloves, gown, drapes, chlorhexidine, wound dressing.
• Local anesthetic agent, 25 gauge needle, syringe.
• Thoracentesis kit: Can include:  8-Fr over the needle catheter, 18-gauge needle, stopcock, large syringe, drainage bag.
  • Consideration:
    • Diagnostic purposes where only small volume needed (eg. 30 mL), 18-gauge needle without catheter may be used.
    • Any larger volume aspiration risk visceral pleural laceration.
      • In these cases use an over-the-needle catheter or Seldinger technique (wire / dilator / catheter).
      • Typically 8 Fr catheter can suffice for large volume drainages.
      • Note: with Seldinger technique, catheters can range from 6 – 14 Fr.
    • Otherwise for diagnostic needle thoracentesis consider 50 mL syringe with small gauge needle (21-22 gauge), 40 mm length.
      • Larger bore needles possibly associated with increased pneumothorax rate (weak evidence).
      • Larger body habitus may necessitate longer needles – eg. 20-gauge lumbar puncture needle (generally 100 mm length) can be considered if your kit doesn’t already supply 100 mm needles.
• Sedation typically not required.
• Bedside ultrasound.
  • Sterile cover and gel not typically needed for simple thoracentesis.
    • Consider use in more complicated cases.
      • When using guide wires (eg. Seldinger technique).
      • Loculated effusions.
      • Body habitus that may require site selection reconfirmation during procedure.
• Informed consent.

Technique (Over the Needle Catheter)

• Identify anatomical structures with ultrasound and locations of lung sliding.
  • Pleural effusions can be free-flowing or loculated.
  • Identify effusion, and choose safe intercostal space – generally 1 intercostal space below superior margin of small effusions, and 2-3 spaces below larger ones (beware diaphragm).
    If ultrasound not available, perform only if evidence of free-flowing pleural effusion.  Use clinical landmarks in conjunction with CXR or CT findings – eg. one or two interspaces below decreased breath sounds, above 9th rib as it avoids diaphragmatic puncture.
  • Use needle cap to mark site before applying chlorhexidine.
• Determine appropriate angle and depth of needle.
  • Adjust needle length as needed per depth of fluid seen.
• Sterilize with chlorhexidine and sterile drapes.
• Local anesthetic (eg. 1 or 2 % lidocaine without epinephrine).
  • Infiltrate with local: epidermis, upper border rib, parietal pleura.
    • When advancing forward, retract plunger of syringe to watch for bloody aspiration and to confirm the point of reaching the pleural effusion.
    • Ensure anesthetization of the parietal pleura, as it produces significant pain in the procedure.
• Cut through skin with scalpel.
• Insert over-the-needle catheter through skin and provide continuous negative pressure.
  • Advance until fluid aspirated, and then advance approx. 5 mm further to ensure depth.
  • Hold needle, and advance catheter. Then remove needle.
    • Ensure stopcock attached – this prevents pneumothorax on patient inspirations.
• Withdraw 50 mL of pleural fluid and send for analysis.
  • Cell count, protein, LDH, pH, glucose, amylase, gram stain, culture, cytology.
• Drainage techniques (use sutures to stabilize catheter in place, see video 3 below):
  • Gravity Drainage
  • Syringe Drainage
  • Vacuum Bottle Drainage|
    Drain generally until flow slows or stops.

• Removal technique:
  • Remove catheter while patient holds breath at end expiration. Place an occlusive dressing. Video: Chest Tube Removal (HealthPartnersMedEd).

Reasons For a ‘Dry’ Tap

• Errors in skin land-marking
• Poor angle replication
• Patient movement
• Needle blockage
• Short needle
• Unexpandable lung – entrapped or trapped fluid.

Follow-up

• Consider post-procedure chest x-ray.
• Post-procedure ultrasound demonstrating multiple sites of lung sliding may adequately exclude procedure associated pneumothorax.

Complications

• Several: pain at puncture site, bleeding, pneumothorax, empyema, spleen or liver injury, re-expansion pulmonary edema.
  • Pneumothorax:
    • Most common, decreased incidence with ultrasound use.
• Risk factors: effusions < 250 mL, obesity, multiple loculations, coagulopathy, mechanical ventilation, large volume drainages.

Tips to Avoid Complications

• Understand equipment, especially three-way stop cock.
• Establish level of effusion. Lateral decubitus radiography can distinguish free-flowing from loculated effusions.
• Check for coagulopathy and/or thrombocytopenia prior to procedure.
• Always advanced used needles on superior surface of the rib – avoids intercostal vessel injury.
• Limit drainage to under 1500 mL – avoids post-expansion pulmonary edema.
• Remove needle with patient at end expiration (negative intrathoracic pressure during inspiration can cause pneumothorax).
  • Otherwise, if stop-cock is affixed to catheter, ensure it is in a position that is closed to the patient.

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5. EMCrit – The Pigtail Video. Seldinger Technique Using Pigtail catheter.

   
   

1. Ultrasound-guided thoracentesis. (Source: uptodate.com).

   
   

2. Patel, Indravadan J., et al. “Society of Interventional Radiology Consensus Guidelines for the Periprocedural Management of Thrombotic and Bleeding Risk in Patients Undergoing Percutaneous Image-Guided Interventions—Part II: Recommendations.” Journal of Vascular and Interventional Radiology, vol. 30, no. 8, 2019, doi:10.1016/j.jvir.2019.04.017.

   
   

3. Kozmic, Sarah E., et al. “Factors Associated with Inpatient Thoracentesis Procedure Quality at University Hospitals.” The Joint Commission Journal on Quality and Patient Safety, vol. 42, no. 1, 2016, doi:10.1016/s1553-7250(16)42004-0.

   
   

4. Thomsen, Todd W., et al. “Thoracentesis.” New England Journal of Medicine, vol. 355, no. 15, 2006, doi: 10.1056/NEJMvcm053812.