Thoracentesis is a procedure by which fluid is removed from either
hemithorax through a needle or small catheter inserted for that
purpose, and may be a diagnostic or therapeutic procedure.
- ▪ Pleural tap: Typically used to describe a diagnostic
- ▪ Transudate: Pleural fluid where pathologic analysis of
the fluid shows little protein and few cells—consistent
with several primary etiologies
- —Congestive heart failure
- —Nephritic syndrome
- —Atelectasis or trapped lung
- ▪ Exudate: Pleural fluid with protein and or cells
- —Pleural or pulmonary malignancy
- —Connective tissue disease
- —Pulmonary embolism
- —Lymphatic disease
- ▪ There are many indications for thoracentesis that
can generally be categorized under one of two headings:
- —Diagnostic: Evaluation of pleural fluid to
diagnose primary disease process
- —Therapeutic: Done to drain fluid to improve respiratory
status of the patient
- ▪ Contraindications.
- —Bleeding diathesis (ie, low platelets, abnormal
- —Small effusion with significant risk of injury
to the lung during performance of the procedure
- —Bullous disease on the side of the effusion
- —Positive pressure ventilation (relative)
- ▪ The location of the effusion should be identified
radiographically (ie, chest x-ray, CT scan, or ultrasound).
- ▪ Prior to procedure, the patient should be consented, prepped,
and the universal protocol should be performed as per Section I.
- ▪ The patient is typically positioned in an upright position
allowing fluid to settle at the bottom of the hemithorax, and percussion
may be used to identify the interface between lung and fluid (Figure
- ▪ The site is marked and local anesthetic infiltrated down
to the rib (Figure 31-2).
- ▪ A needle is introduced into the pleural space and fluid
withdrawal confirmed (Figure 31-3).
- ▪ A catheter is then inserted into the effusion using one
of a variety of techniques, including catheter-through-needle, catheter-over-needle,
and Seldinger exchange (Figure 31-4).
- ▪ The fluid is then drained into a vacuum bottle (Figure
31-5) or drainage bag.
- ▪ The fluid is then sent off for appropriate diagnostic studies.
Percussive evaluation of pleural fluid meniscus.
Site marked for needle insertion.
Fluid aspirated from effusion.
Catheter threaded into chest cavity.
Pleural fluid drained into vacuum bottle.
Clinical Pearls and Pitfalls
- ▪ The drainage
catheter may stop draining if the tip sucks up against lung or pleura,
in which case the patient can be repositioned ...