II. Indications: Diagnostic Thoracentesis
- Effusion >1 cm high on decubitus XRay in an undiagnosed patient
- Effusion not explained by other cause
- CHF not responding within 3 days to diuresis
- Asymmetric Pleural Effusions
- Fever
- Effusion >5 cm high on lateral XRay in Pneumonia patient
- Evaluate and treat for Parapneumonic Effusion, empyema
- Avoid Thoracentesis for suspected transudative bilateral Pleural Effusions
- Example: Congestive Heart Failure
- Exception: Effusion not explained by other cause (see above)
III. Indications: Therapeutic Thoracentesis
- Large Pleural Effusion (>50% of hemithorax) with Dyspnea and/or hemodynamic instability
- Empyema (or other loculated fluid)
- Directed Chest Tube or drain is typically performed instead
IV. Contraindications: Relative
- Mechanical Ventilation is NOT a contraindication to Thoracentesis
- Conditions in which Chest Tube is indicated instead of Thoracentesis
- Pneumothorax
- Hemothorax
- Empyema
- Complicated Parapneumonic Effusion
- Pleurodesis for malignant effusion
- Small Pleural Fluid pocket
- Ultrasound with Pleural Effusion <1.5 cm (or with intervening tissue such as liver)
- Decubitus Chest XRay with <1 cm Pleural Effusion
- CT Chest with <2 to 2.5 cm Pleural Effusion
- Local cutaneous condition (esp. Cellulitis) interfering with percutaneous needle access
- Severe Coagulopathy
- ProTime or Partial Thromboplastin Time twice normal
- Platelet Count <25,000
- Serum Creatinine > 6 mg/dl
-
Chest XRay with mediastinal shift toward effusion
- Suggests negative pleural pressure
- Suggests Bronchial obstruction
- Bronchoscopy recommended in these cases
V. Precautions
- Limit fluid removal to 1500 cc
- Some experts recommend complete drainage
- Removal of volumes >1000 to 1500 cc risk reexpansion Pulmonary Edema
-
Ultrasound-guided Thoracentesis is associated with fewer complications
- Use low frequency probe
- Ultrasound offers real-time guidance
- Identifies largest Pleural Fluid pocket
- Prevents Arterial Puncture
- Clinical exam with chest percussion and auscultation is by contrast imperfect with increased risk
- Pneumothorax occurs in 10-39% of cases
- Dry tap (more than half of which are intraabdominal) occurs in up to 15% of patients
- References
- Keep stopcock closed to patient at all times when not draining fluid
-
Coagulopathy correction prior to Thoracentesis is performed in some guidelines
- Some guidelines recommend correcting to INR <2, holding Anticoagulation, Platelet Transfusion if <50k
- Coagulopathy correction before Thoracentesis is not evidence based, but follow local expert opinion and guidelines
VI. Technique
- Patient seated with arms and head supported
-
Ultrasound to localize best insertion site
- Lower complication rates with Ultrasound assume real-time needle guidance (instead of pre-marking skin)
- Often best site is posterior axillary (or mid-axillary line) at 5th intercostal space
- Do not use an insertion site below the 8th intercostal space
- Position insertion site above the rib
- Minimum pocket depth (visceral to parietal pleura) 1.5 cm for Thoracentesis
- Sterile preparation
- Cleanse the insertion site
- Consider encasing the Ultrasound probe in sterile cover for guidance during procedure
-
Local Anesthesia
- Insert needle over top of rib and raise a skin wheel
- Inject Lidocaine 1% over the top of rib and at the pleura
- Identify the depth at which Pleural Fluid is aspirated with Anesthetic needle
- Remove the Anesthetic needle
- Diagnostic Throacentesis needle insertion
- Fluid may be aspirated with 18 to 21 gauge 1.5" needle with 20 to 50 cc syringe
- Therapeutic Thoracentesis catheter insertion
- Make a small incision at the insertion site with scalpel
- Insert Thoracentesis needle, passing over the rib
- Aspirate (back pressure on syringe) while inserting Thoracentesis needle
- Once Pleural Fluid is aspirated, advance the catheter over the needle and into the pleural space
- Cover catheter with a 3-way stop-cock and ensure it is closed to patient until use
- Drain Pleural Fluid
- Allow fluid to drain into container
- Stop fluid flow at 1500 cc (or empty completely based on local guidelines)
- Larger volume removal is a risk for Reexpansion Pulmonary Edema
- Remove the Thoracentesis catheter
- Patient takes a deep breath or hums while the catheter is removed
- Dress the insertion site with an Occlusive Dressing
- Post-Thoracentesis Chest XRay Indications
- Air is withdrawn in Thoracentesis catheter
- Multiple Thoracentesis attempts are required
- Significant symptoms during or after the procedure
VII. Labs
- See Pleural Fluid Examination
- Process sample within 4 hours of fluid collection
- Obtain 20 to 40 ml fluid divided over 3 sterile tubes (containing Anticoagulation)
- Special tubes
- Anaerobic Heparinized tube on ice for pH
- Anaerobic and aerobic culture tubes
VIII. Complications
-
Pneumothorax (5-20%)
- Requires Chest Tube in 2%
- Increased risk in COPD
- Decreased risk with experienced clinician and Ultrasound guidance
- Reexpansion Pulmonary Edema (<1%)
- Higher risk if >1000 to 1500 cc Pleural Fluid removed
- Mortality may be as high as 20%
- Rare but important complications
- Infection (2%)
- Hemothorax (<1%)
- Occurs with subcostal vascular puncture
- Higher risk in elderly, especially with Coagulopathy
- Splenic Laceration
- Tumor seeding of needle tract
- Peri-procedure symptoms that may predict Pneumothorax
- Cough during procedure
- Increased Dyspnea
- Chest Pain
- Other peri-procedure symptoms
IX. Follow-up: Post-procedure Chest XRay Indications
- Not required unless otherwise indicated by symptoms or signs of complication
- Post-procedure symptoms (Chest Pain, Dyspnea)
- Signs of Pneumothorax post-procedure
- Voice transmission absent superior to Thoracentesis
- Tactile fremitus absent superior to Thoracentesis
X. Interpretation
XI. References
- Attum (2018) Crit Dec Emerg Med 32(2):18-9
- Natesan (2020) Crit Dec Emerg Med 34(7): 29-41
- Sachdeva (2013) Clin Chest Med 34(1): 1-9 [PubMed]