Abdominal Paracentesis

Indications Top

1. Diagnostic: A new diagnosis of ascites (either in an outpatient or inpatient setting), suspected spontaneous bacterial peritonitis, usually each hospitalization of a patient with cirrhosis and ascites (as this is frequently associated with spontaneous bacterial peritonitis that is asymptomatic or causes only minor symptoms), evaluation of penetrating or blunt abdominal injury.

2. Therapeutic: Initial treatment of large ascites (one-time fluid evacuation); ascites refractory to diuretics (repeated paracenteses may be necessary); to relieve respiratory distress due to ascites.

Contraindications Top

Disseminated intravascular coagulation or severe (symptomatic) bleeding disorder not responding to vitamin K and fresh-frozen plasma (FFP), acute abdominal conditions requiring urgent surgery. High international normalized ratio (INR) or low platelet counts associated with liver cirrhosis are not an absolute contraindication to paracentesis, but the threshold where correction may be required is not known. Infection overlying the paracentesis site (eg, cellulitis). Lack of patient cooperation or consent.

Potential ComplicationsTop

Hematoma of the abdominal wall (1%), infection of the ascitic fluid, perforation of the bowel or urinary bladder, and hemoperitoneum (<1/1000 patients) or pneumoperitoneum. In the case of therapeutic paracentesis, hypotension (caused by a blood volume shift to the decompressed visceral circulation), renal impairment (including hepatorenal syndrome), and electrolyte disturbances; persistent leakage of ascitic fluid after the procedure, especially in patients with refractory ascites.

Proceed with caution in cases of pregnancy, hepatosplenomegaly, intra-abdominal adhesions, bowel obstruction, distended bladder, or major surgical scars suggesting complicated intra-abdominal anatomy. In such instances, radiologic-guided procedure, usually with ultrasonography, may be required.

Patient PreparationTop

Obtain informed consent, documented as required in your institution. The patient should void prior to the procedure if a urinary catheter is not in place. It is mandatory to maintain good intravascular volume using infusion of a crystalloid or colloid (albumin). In most patients with asymptomatic coagulopathy, the administration of FFP or platelet concentrate is not necessary. Place the patient in a semirecumbent position (with the trunk elevated).

EquipmentTop

Note: If available, a standard dedicated paracentesis kit may be preferred in most situations, especially with large-volume paracentesis. If not available, the following equipment can be used:

1) Equipment for surgical field preparation (see Surgical Field Preparation for Small Procedures) and infiltration anesthesia (see Infiltration Anesthesia).

2) Catheter with a needle as for peripheral vein catheterization, bore 1.2 to 1.7 mm (18-16 gauge, 45 mm in length, allowing for fluid aspiration). A longer needle is necessary in patients with a thick abdominal wall (obesity or significant abdominal wall edema).

3) Three-way stopcock, drain tubing as for drip infusion, bottle for fluid collection (if not using a dedicated paracentesis kit).

4) Scalpel for skin incision if using a large-bore catheter.

5) Ultrasound availability and use is preferred.

Site of ParacentesisTop

Ultrasound guidance, when available, is preferred. A low-frequency abdominal probe or cardiac probe can be used to scan the abdomen to look for drainable fluid collections. Simple transudative ascites (high serum-ascites albumin gradient) is anechoic and can be contrasted with the hyperechoic bowel lying below; complex ascites can have a more complex echogenic appearance. Care should be taken to avoid a distended urinary bladder, which could be mistaken for ascites (as noted above, the patient should void if the bladder is not already decompressed with a Foley catheter). A drainable ascites pocket should have no overlying structures and be ≥3 cm deep. The site can be marked prior to skin preparation and draping.

If ultrasonography is not available, percuss the abdominal wall to verify the fluid level. The optimal paracentesis site usually lies 2 to 3 cm below the umbilicus or at a third of the length of the lower line connecting the anterior superior iliac spine with the umbilicus on the left side, less frequently on the right side.

ProcedureTop

1. Prepare the surgical field (see Surgical Field Preparation for Small Procedures). Infiltrate the skin, subcutaneous tissue, and muscles down to the peritoneum using 1% or 2% lidocaine (see Infiltration Anesthesia).

2. Pull the skin taut down and insert a syringe with a needle while aspirating continuously until the peritoneum is penetrated and fluid outflow is confirmed. Advance the catheter over the needle (or alternatively introduce the catheter over a guidewire as in pericardiocentesis). A 3-way stopcock can be used to control the drainage of fluid while collection setup is connected.

3. After diagnostic collection of 50 to 100 mL of fluid or completion of therapeutic decompression using vacuum collection bottles, protect the puncture site with a sterile dressing.

After the ProcedureTop

Removal of larger amount of ascites may trigger a potentially harmful hemodynamic reaction (postparacentesis circulatory dysfunction), which is why volume replacement in such situations is considered standard practice. Our practice is to administer 6 to 8 g IV albumin in the form of a 20% to 25% solution for every liter of removed fluid over 4 to 5 L rather than using other volume expanders.Evidence 1Weak recommendation (benefits likely outweigh downsides, but the balance is close or uncertain; an alternative course of action may be better for some patients). Moderate Quality of Evidence (moderate confidence that we know true effects of the intervention). Quality of Evidence lowered due to imprecision (mortality) and indirectness (postparacentesis circulatory dysfunction). Bernardi M, Caraceni P, Navickis RJ, Wilkes MM. Albumin infusion in patients undergoing large-volume paracentesis: a meta-analysis of randomized trials. Hepatology. 2012 Apr;55(4):1172-81. doi: 10.1002/hep.24786. PubMed PMID: 22095893.