II. Indications: Diagnostic Thoracentesis

  1. Effusion >1 cm high on decubitus XRay in an undiagnosed patient
  2. Effusion not explained by other cause
    1. CHF not responding within 3 days to diuresis
    2. Asymmetric Pleural Effusions
    3. Fever
  3. Effusion >5 cm high on lateral XRay in Pneumonia patient
    1. Evaluate and treat for Parapneumonic Effusion, empyema
  4. Avoid Thoracentesis for suspected transudative bilateral Pleural Effusions
    1. Example: Congestive Heart Failure
    2. Exception: Effusion not explained by other cause (see above)

III. Indications: Therapeutic Thoracentesis

  1. Large Pleural Effusion (>50% of hemithorax) with Dyspnea and/or hemodynamic instability
  2. Empyema (or other loculated fluid)
    1. Directed Chest Tube or drain is typically performed instead

IV. Contraindications: Relative

  1. Mechanical Ventilation is NOT a contraindication to Thoracentesis
  2. Conditions in which Chest Tube is indicated instead of Thoracentesis
    1. Pneumothorax
    2. Hemothorax
    3. Empyema
    4. Complicated Parapneumonic Effusion
    5. Pleurodesis for malignant effusion
  3. Small Pleural Fluid pocket
    1. Ultrasound with Pleural Effusion <1.5 cm (or with intervening tissue such as liver)
    2. Decubitus Chest XRay with <1 cm Pleural Effusion
    3. CT Chest with <2 to 2.5 cm Pleural Effusion
  4. Local cutaneous condition (esp. Cellulitis) interfering with percutaneous needle access
  5. Severe Coagulopathy
    1. ProTime or Partial Thromboplastin Time twice normal
    2. Platelet Count <25,000
    3. Serum Creatinine > 6 mg/dl
  6. Chest XRay with mediastinal shift toward effusion
    1. Suggests negative pleural pressure
    2. Suggests Bronchial obstruction
    3. Bronchoscopy recommended in these cases

V. Precautions

  1. Limit fluid removal to 1500 cc
    1. Some experts recommend complete drainage
    2. Removal of volumes >1000 to 1500 cc risk reexpansion Pulmonary Edema
  2. Ultrasound-guided Thoracentesis is associated with fewer complications
    1. Use low frequency probe
    2. Ultrasound offers real-time guidance
      1. Identifies largest Pleural Fluid pocket
      2. Prevents Arterial Puncture
    3. Clinical exam with chest percussion and auscultation is by contrast imperfect with increased risk
      1. Pneumothorax occurs in 10-39% of cases
      2. Dry tap (more than half of which are intraabdominal) occurs in up to 15% of patients
    4. References
      1. Jones (2003) Chest 123:418-23 [PubMed]
      2. Soni (2015) J Hosp Med 10(12): 811-6 [PubMed]
  3. Keep stopcock closed to patient at all times when not draining fluid
  4. Coagulopathy correction prior to Thoracentesis is performed in some guidelines
    1. Some guidelines recommend correcting to INR <2, holding Anticoagulation, Platelet Transfusion if <50k
    2. Coagulopathy correction before Thoracentesis is not evidence based, but follow local expert opinion and guidelines

VI. Technique

  1. Patient seated with arms and head supported
  2. Ultrasound to localize best insertion site
    1. Lower complication rates with Ultrasound assume real-time needle guidance (instead of pre-marking skin)
    2. Often best site is posterior axillary (or mid-axillary line) at 5th intercostal space
    3. Do not use an insertion site below the 8th intercostal space
    4. Position insertion site above the rib
    5. Minimum pocket depth (visceral to parietal pleura) 1.5 cm for Thoracentesis
  3. Sterile preparation
    1. Cleanse the insertion site
    2. Consider encasing the Ultrasound probe in sterile cover for guidance during procedure
  4. Local Anesthesia
    1. Insert needle over top of rib and raise a skin wheel
    2. Inject Lidocaine 1% over the top of rib and at the pleura
    3. Identify the depth at which Pleural Fluid is aspirated with Anesthetic needle
    4. Remove the Anesthetic needle
  5. Diagnostic Throacentesis needle insertion
    1. Fluid may be aspirated with 18 to 21 gauge 1.5" needle with 20 to 50 cc syringe
  6. Therapeutic Thoracentesis catheter insertion
    1. Make a small incision at the insertion site with scalpel
    2. Insert Thoracentesis needle, passing over the rib
    3. Aspirate (back pressure on syringe) while inserting Thoracentesis needle
    4. Once Pleural Fluid is aspirated, advance the catheter over the needle and into the pleural space
    5. Cover catheter with a 3-way stop-cock and ensure it is closed to patient until use
  7. Drain Pleural Fluid
    1. Allow fluid to drain into container
    2. Stop fluid flow at 1500 cc (or empty completely based on local guidelines)
      1. Larger volume removal is a risk for Reexpansion Pulmonary Edema
  8. Remove the Thoracentesis catheter
    1. Patient takes a deep breath or hums while the catheter is removed
    2. Dress the insertion site with an Occlusive Dressing
  9. Post-Thoracentesis Chest XRay Indications
    1. Air is withdrawn in Thoracentesis catheter
    2. Multiple Thoracentesis attempts are required
    3. Significant symptoms during or after the procedure
      1. Chest Pain
      2. Dyspnea

VII. Labs

  1. See Pleural Fluid Examination
  2. Process sample within 4 hours of fluid collection
  3. Obtain 20 to 40 ml fluid divided over 3 sterile tubes (containing Anticoagulation)
  4. Special tubes
    1. Anaerobic Heparinized tube on ice for pH
    2. Anaerobic and aerobic culture tubes

VIII. Complications

  1. Pneumothorax (5-20%)
    1. Requires Chest Tube in 2%
    2. Increased risk in COPD
    3. Decreased risk with experienced clinician and Ultrasound guidance
  2. Reexpansion Pulmonary Edema (<1%)
    1. Higher risk if >1000 to 1500 cc Pleural Fluid removed
    2. Mortality may be as high as 20%
  3. Rare but important complications
    1. Infection (2%)
    2. Hemothorax (<1%)
      1. Occurs with subcostal vascular puncture
      2. Higher risk in elderly, especially with Coagulopathy
    3. Splenic Laceration
    4. Tumor seeding of needle tract
  4. Peri-procedure symptoms that may predict Pneumothorax
    1. Cough during procedure
    2. Increased Dyspnea
    3. Chest Pain
  5. Other peri-procedure symptoms
    1. Vasovagal Syncope

IX. Follow-up: Post-procedure Chest XRay Indications

  1. Not required unless otherwise indicated by symptoms or signs of complication
  2. Post-procedure symptoms (Chest Pain, Dyspnea)
  3. Signs of Pneumothorax post-procedure
    1. Voice transmission absent superior to Thoracentesis
    2. Tactile fremitus absent superior to Thoracentesis

XI. References

  1. Attum (2018) Crit Dec Emerg Med 32(2):18-9
  2. Natesan (2020) Crit Dec Emerg Med 34(7): 29-41
  3. Sachdeva (2013) Clin Chest Med 34(1): 1-9 [PubMed]

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