Removal of ascitic fluid from the peritoneal cavity.
- Biochemical analysis
Tense ascites in
- Malignant ascites
- Chronic liver disease
- Empty bladder - if not catheterised, ask patient to void prior to procedure
- Intravenous access is useful in patients with cirrhosis as rapid fluid shifts can occasionally cause hypotension.
- Some people advocate checking clotting. In patients with liver failure, the INR is often deranged, but due to reductions in several other clotting factors, this does not represent the true state of coagulation.
For therapeutic drainage, a intravenous cannula attached to appropriate tubing may suffice, but getting suitable connectors to connect and maintain a sterile drainage system can be difficult.
Bonanno® catheters are commonly used for therapeutic ascitic drainage. This is a pig-tail catheter with multiple small holes at the end. It is inserted as a catheter-over-needle device, but is marketed and licensed for suprapubic catheterisation, rather than paracentesis. They are not very good suprapubic catheters as they are very slender and more easily blocked than wider bore suprapubic catheters, but make good ascitic drains. Other alternatives include the Seldinger-style chest drains, but the commonly stocked sizes are often quite large bore.
- Glove and gown.
- Skin antisepsis.
- Pick site.
- Avoid prominent superficial veins and the course of the inferior epigastric vessels.
- Use midline or a point along the imaginary line between the umbilicus and anterior superior iliac spine, picking a spot where the dullness begins. This is usually at least two-thirds along this line (from the umbilicus) as this avoids the rectus abdominis muscles and gives a point of insertion where the abdominal wall muscles tend to become aponeurotic.
- Administration of local anaesthetic. It is often possible to aspirate ascitic fluid with this syringe.
- A small nick is sometimes needed to allow catheter to pass.
- Blockage of catheter
- Infection leading to peritonitis
- Perforation of bladder or bowel.
- Persistent leak from puncture site.
The drain is usually left on free drainage, allowing fluid to escape over a period of hours. Relieving a collection too fast may cause instability in circulation and is to be avoided. For this reason, some recommend clamping the drain after a certain volume has been reached, together with albumin replacement is recommended in liver disease. The issues of fluid shifts are less of an issue in malignant ascites.
On the other hand, leaving a drain in increases the risk of infection. Depending on the cause of the ascites and the intention and anticipated outcome of treatment, the drain might be left in place for a maximum of 12 hours, or terminally for many days.