2. • A potential space exists in the left and right side of the chest cavity between
the inner chest wall and lung. A trace amount of fluid is found in this space as
part of healthy lymphatic drainage, providing lubrication between the lung
parenchyma and musculoskeletal structures of the rib-cage during expansion
(inhalation) and recoil (exhale).
• Excess fluid is pathological. The volume of excessive fluid, the rate of
accumulation, the cellular content of the fluid, and the chemical composition
of the fluid are all used to guide the management and the differential
diagnosis of the underlying etiology.
• Thoracentesis is done in either a supine or sitting position depending on
patient comfort, underlying condition, and the clinical indication.
Anatomy and Physiology.
3. Indications
The indications for thoracentesis are relatively broad including diagnostic and
therapeutic clinical management.
• Thoracentesis should be performed diagnostically whenever the excessive fluid is
of unknown etiology. It can be performed therapeutically when the volume of fluid
is causing significant clinical symptoms.
• Typically, diagnostic thoracentesis is a small volume (single 20cc to 30cc syringe).
Unless the etiology is obvious, a first-time thoracentesis should have a diagnostic
sample collected for laboratory and pathology analysis.
• Typically, therapeutic thoracentesis is a large volume (multiple liters of fluid). A
small sample of a large volume thoracentesis should be sent for analysis when the
etiology of the fluid is unknown or there is a question of a change in the etiology
(e.g., new infection, decompensated chronic condition).
• If the volume of fluid is anticipated to reaccumulate quickly, a drain is often left in
place to collect this fluid. This often is seen in trauma (e.g., hemothorax), cancer
(e.g., malignant effusion), post-operatively (e.g., cardiothoracic post-operative
healing/inflammatory conditions), and end-stage metabolic conditions with the
systemic excessive colloid leak (e.g., cirrhosis or malabsorption syndromes).
• A fluid collection that is believed to be infected should be drained to eliminate the
source of infection and/or reservoirs of the infection.
4. Contraindications
• Coagulation abnormalities (however, fresh plasma can be used)
• . Pts receiving mechanical ventilation since positive pressure ventilation may bring
the lungs close to the thoracentesis needle and increase the risk of pneumothorax
• . Severe hemodynamic compromise (The thoracentesis needle should not pass
through sites of cutaneous infection such as cellulitis or herpes zoster)
5. Equipments
• IV needle catheter
• Skin cleansing agent
• Gauze
• Sterile gloves
• A drape
• Hemostat
• 1 or 2 % Lidocaine
• 10 mL syringe and 22 and 25 gauge needles
6. For collection of pleural fluid;
• 18 or 20 gauge over the needle catheter
• 60 mL syringe
• A 3-way stop cock
• A sterile drainage tubing
• Specimen tubes and large evacuated container for collection of the fluid
• Sterile occlusive dressing
7. Preparation
• Explain the procedure to the pt and obtain written informed consent
• Also, verify the pts identity
• Mark the correct site for puncture
• Conduct a procedural time out. It takes place immediately before the procedure
and it consist of (Confirmation by all members of care team, Pts identity, Procedure
he/she is to undergo and Site of the procedure are all correct)
8. Technique
• Place the pt. in a sitting position on the edge of the bed with his/her arms resting
on a table.
* (The height of the effusion is determined by auscultation and percussion of the
posterior chest wall)
• Using the skin marking pen, mark the needle insertion site.
* (The site should be 5 to 10 cm lateral to the spine and at least 1 or 2 intercostal
spaces below the top of the effusion. Note that the needle should not be inserted
below the 9th rib)
• Prepare the area with antiseptic solution and apply a sterile drape
• Using a 25 gauge needle, place wheel of local anaesthetics like 1 0 or 2 % Lidocaine
along the superior edge of the rib that lies below the selected intercostal space.
9. • Switch to a 22 gauge needle and begin to anaesthetize the deeper tissues.
• (The inferior surface of the rib must be avoided since the intercostal vessels
and nerve are located in this region, hence, ensure that you walk the needle
over the superior aspect of the rib alternately injecting anaesthetic ad
pulling back on the plunger as you advance.
• Once the needle enters the pleural space, the pleural fluid will begin to fill
the syringe.
• Then, inject more anaesthetic at this point to anaesthetize the highly
sensitive parietal pleura.
• Note the depth of penetration and then withdraw the needle. If needed,
you can use the hemostat to the exposed portion of the needle in order to
mark the depth of the pleural space.
10. Pleural Fluid Aspiration
• Attach on 18 gauge over the needle catheter to a syringe and advance it along the
superior surface of the rib. Keep pulling back on the plunger as you proceed to the
predetermined depth of the pleural space.
• Once fluid is aspirated, immediately stop advancing the needle and guide the
plastic catheter over the needle.
• When the catheter is finally inserted, remove the needle as the pt. exhales or
hums. The exposed hub of the catheter should be covered immediately with your
finger to prevent the entry of air into the pleural space.
• Then attach a 3-way stopcock and large syringe to the catheter and continue to
aspirate the fluid
• When the syringe is full, adjust the stopcock so that it’s close to the pt. only when
fluid is being actively drained.
* If additional fluid needs to be drained for therapeutic purposes, attach the
collecting tubing to the stopcock and to the evacuated container.
11. • Open the stopcock to the pt. and to the tubing and allow the evacuated container
to fill.
* Generally, you should remove no more than 1500 ml of pleural fluid. The removal
of large volumes may result in post expansion pulmonary edema
• On completion of fluid collection you should rapidly remove the catheter as the pt.
holds his/her breath at end expiration.
• Cover the needle insertion site with an occlusive dressing and clean the
surrounding skin.
* At the end of the procedure make sure that all needles are placed into the
appropriate safety devices.
12. Pleural Fluid Analysis
• Aspirated fluid should be placed in specimen tubes before the large evacuated
container is filled or while it’s filling.
* A tube without additives should be used for chemical analysis such as the
measurement of LDH, protein and glucose levels.
• An EDTA (Ethylenediaminetetraacetic acid) treated tube should be used for the cell
count.
• Specimens for cytologic and microbiologic analysis and for other tests may be
required depending on the clinical circumstances.
* Analysis of pleural fluid helps to differentiate the Transudate commonly caused by
congestive heart failure/cirrhosis from an Exudate which can be caused by processes
such as bacteria, cancer and trauma.
13. Transudate/Exudate Difference
Transudate
• Pleural fluid protein is < 0.5 serum protein
• Pleural fluid LDH < 0.6 serum LDH
• Pleural fluid LDH <2/3 upper limit normal
Exudate
• Pleural fluid protein is > 0.5 serum protein
• Pleural fluid LDH > 0.6 serum LDH
• Pleural fluid LDH > 2/3 upper limit normal
14. Complications
• Pneumothorax though uncommon hence chest x-ray should be performed if air is
aspirated during procedure, If the pt. develops chest pain, dyspnea, hypoxemia or
if the pt is critically ill or mechanically ventilated.
• Other complications include pain, coughing and localized infection.
• More serious complications are hemothorax, intraabdominal organ injury, air
embolism and post expansion pulmonary edema.
15. Questions…
1. What are the indications and contraindications for thoracentesis?
2. Which part of the rib should you place a wheel of local anaesthetics
using a 25 gauge?
3. On which surface of the rib are the intercostal vessels and nerve are
located?
4. What are the ifferences between exudate and transudate?
5. What are the complications of thoracentesis?