Indication
- Diagnostic tap of a pleural effusion
- Therapeutic tap of a pleural effusion to relieve respiratory distress
- Repeated 'tapping' of fluid may be useful in palliative care though the recurrence rate is high without pleurodesis
Precautions
- Only competent staff (or training staff supervised by competent staff) should perform this procedure
Caution
- Bleeding diathesis or anticoagulant therapy
- Mechanical ventilation (risk of tension pneumothorax or bronchopleural fistula if the lung is punctured)
- Localised skin disease over the proposed skin puncture site
Equipment
- 1% or 2% lidocaine
- Basic dressing pack with sterile towels
- Sterile gloves
- Iodine or chlorhexidine solutions
- Sterile universal containers
- 21-gauge (green) needles and 27-gauge (orange) needles
- 16-gauge (grey) cannula
- 10 and 20 ml syringe
Procedure
- Explain and get informed consent and what you are about to do. Sit the patient on the edge of the bed, arms folded leaning forwards with arms resting on a pillow on a typical cross table. Ensure maximum comfort. Administer oxygen and use pulse oximetry throughout the procedure if the patient is breathless.
- Check the site - side and percuss and re-examine the CXR to ensure you are on the correct side. mark the spot posterolaterally. The conventional site is about 10 cm lateral to the spine and 1-2 rib spaces below the upper level of the fluid.
- Sometimes with difficult cases or where the effusion is loculated then get an ultrasound scan to mark the position. Wear sterile gloves and clean the area with a 10-20 cm diameter and around the area apply the sterile towels to give you a sterile field.
- Draw up and infiltrate the local area with 5-10 ml of lidocaine. Initially use a blue or orange needle and then switch to the green needle and infiltrate down to the pleura. Aspire as you go and do not inject lidocaine if you are in a vessel. Once you penetrate the pleural space you should be able to aspirate straw-coloured pleural fluid. Always use the upper margin of the rib and avoid the undersurface where the neuromuscular bundle lies.
- If it is only a diagnostic tap you can consider just aspirating 20 mls of fluid and leave it at that but if therapeutic or cytology needed then a greater volume is needed and you should now insert the grey venflon along the anaesthetised track or sometimes there are complete systems with their own needle and drainage bag which can be used which may be connected to a three-way tap. In this case, a 50 ml syringe can be joined up and used to aspirate and then expel the contents into a bag or other receptacle.
- Once you have drained 1-1.5 L of fluid, remove the cannula and the attached equipment and press over the site with a gauze pad for 1 minute. larger volumes are associated with re-expansion pulmonary oedema.
Test
- Bottle for Microscopy, culture and sensitivity
- Most of the volume can go to cytology to be spun down for cells
- Biochemistry for protein and lactate dehydrogenase (LDH) levels.
- Query TB then Staining for acid-fast staining.
- Fluid on ice and test pH for empyema
- Rheumatoid disease: send for glucose and complement levels.
- Pancreatitis: send some fluid for amylase level.
- Chylothorax: send some fluid for centrifuge, cholesterol and triglyceride levels
Post procedure
- Dispose of all sharps
- Get a CXR and look for changes in the effusion and any sign of a pneumothorax which if small can be just kept under review. take advice as a chest drain may be needed.
- Make a detailed record in the notes of the procedure.
Complications
- Pain during and after the procedure at the puncture site. Consider good analgesia pre and post-procedure. Opiates may be required.
- Pneumothorax seen in up to 30% of pleural aspirations but a chest drain is needed in less than 5%
- Bleeding (may be cutaneous or internal).
- Empyema.
- Damage and puncture of liver or spleen