• Diagnosis
• To relieve symptoms

• All relative. Discuss with consultant
• Severe bullous emphysema or chronic obstructive pulmonary disease (COPD)
• Impaired blood clotting

• If not competent in procedure, organise supervision by a clinician experienced in the procedure 

Use of ultrasound

• Use ultrasound to guide aspiration

• Cleansing pack
• Gloves
• Gown
• Lidocaine 1% plain maximum 20 mL
• 5 mL and 10 mL plastic syringes

Relief of symptoms (removal of large amounts of fluid)

• Pleural aspiration pack (if available)
• otherwise use cannula with 3-way tap and 50 mL syringe

Diagnostic aspiration only

• Green needle and 50 mL syringe

Specimen bottles

Fluid

• 3 sterile bottles (20 mL) for microbiology, biochemistry and cytology
• Oxalate bottle for glucose
• 2 blood culture bottles

Blood

• SST bottle (yellow top) for serum LDH and protein
• Fluoride/oxalate bottle (grey top) for glucose

• Plastic syringe: cap as used for blood gas measurement
• Unfractionated heparin 1000 units/mL
• Wash 5 mL syringe with unfractionated heparin
• Expel unfractionated heparin, leaving unfractionated heparin-coated syringe
• Cap syringe

• Review chest X-ray (PA +/- lateral if available)
• Take blood specimens 

Consent

• Explain procedure and reassure patient
• Obtain and record written consent for therapeutic aspiration
• Complete WHO surgical safety checklist

Site of insertion and position of patient

• Seat patient on bed or chair leaning slightly forward with arms folded and resting on a pillow placed on a support such as a bed table
• Perform chest ultrasound and mark site
• avoid site where pyoderma or Herpes zoster present
• avoid inferior border of rib

Aseptic technique

• Scrub up and prepare patient's skin
• Check pleural aspiration set ensuring that all parts fit tightly together

Local anaesthetic

• Infiltrate skin with lidocaine using orange needle
• Palpate intercostal space, infiltrate (using green needle) 3 mg/kg (maximum 20 mL) of lidocaine 1% plain to parietal pleura, periosteum of lower rib and into pleural space once fluid aspirated

Pleural aspiration

Diagnostic aspiration only

• Use a green needle and 50 mL syringe
• Aspirate 20-50 mL of fluid and expel into specimen bottles
• Put 3-5 mL fluid from large syringe or biochemistry bottle into 5 mL pre-heparinised syringe for pH measurement
• Expel bubbles from syringe and cap it ready for pH analysis
• to prevent ward blood gas analyser dysfunction, perform wash procedure on analyser after pH measurement
• do not send purulent samples for pH analysis

For relief of symptoms

• Connect 3-way tap with 50 mL syringe attached (already connected in pack) to one end of plastic tubing available in pack or 
• Insert pleural aspiration kit needle through chest wall maintaining negative suction
• As soon as fluid aspirated, pull needle out approximately 1 cm and push cannula in further
• Completely remove needle
• Connect other end of plastic tubing to cannula/aspiration kit via three way tap
• Withdraw fluid
• do not aspirate more than 1 L of fluid at one time to avoid re-expansion pulmonary oedema
• If diagnostic sample is needed, aspirate 20-50 mL of fluid into 50 mL syringe and expel into specimen bottles
• connect 5 mL pre-heparinised syringe to 3-way tap
• aspirate 3-5 mL of fluid, expel bubbles from syringe and cap it ready for pH analysis
• to prevent ward blood gas analyser dysfunction, perform wash procedure on analyser after pH measurement
• do not send purulent samples for pH analysis

Troubleshooting

Failure to obtain any fluid

• Needle inserted too low down or too far in
• choose more appropriate site, re-anaesthetise and try again

Needle in diaphragm

• Pleura feels unusually thick and needle moves widely with respiration
• withdraw and adjust angle of approach

Fluid viscous

• Use wider bore needle

No fluid present

• Consider CT to clarify the pleural findings 

Aspiration of blood

• Heavily blood-stained fluid can be seen in malignancy and trauma
• If any concerns stop procedure and seek senior advice 

Lung unable to re-expand

• Will show as increased pull on the syringe plunger
• Stop aspirating
• if patient distressed, let air into pleural space

pH measurement

• Pleural fluid in capped heparinised syringe to measure pH in blood gas analyser
• send to laboratory as soon as possible

Biochemistry

• Send in same sample bag
• 20 mL sterile bottle, and oxalate bottle
• blood in SST bottle (yellow top) and fluoride/oxalate bottle (grey top)
• Use biochemistry form to request pleural fluid profile (ratios of pleural fluid/serum for protein, LDH and glucose)

Histopathology

• Pleural fluid in sterile bottle
• send as much fluid as possible, up to 50 mL

Microbiology

• Send in separate sample bags
• one sterile bottle (20 mL) each for Gram stain, AAFB and TB culture
• two inoculated blood culture bottles for MC&S

Additional pleural fluid tests

• These can be sent in the same bag
• If chylothorax suspected, cholesterol and triglyceride to biochemistry
• if acute pancreatitis or rupture of the oesophagus suspected, amylase (pleural and blood) to biochemistry
• If haemothorax suspected, haematocrit on fluid and blood (purple top) to haematology
• (haematocrit in pleural fluid/peripheral blood haematocrit) >0.5 confirms haemothorax
• If rheumatoid disease suspected, complement to immunology

• Apply small adhesive dressing over puncture site
• Chest X-ray following therapeutic pleural tap. Check for pneumothorax
• if present, see Spontaneous pneumothorax guideline