What are the indications for a paracentesis?
When should you use ultrasound guidance or involve interventional radiology?
When should you correct a coagulopathy?
What is the role of albumin administration?
What is the best site location to enter to reduce the risk of complications?
Paracentesis is a procedure that involves removing ascitic fluid from the abdominal cavity with a needle or catheter. Using local anesthesia, hospitalists, other internists, Emergency Medicine physicians, proceduralists, and radiologists perform this procedure in either an outpatient or inpatient setting. A diagnostic paracentesis can determine the cause of ascites and rule out spontaneous bacterial peritonitis. A therapeutic paracentesis will remove excess fluid.
Dating back to the time of Hippocrates, paracentesis using large bore catheters was the only available option to remove ascitic fluid. In the 1950s, oral diuretics and sodium restriction were introduced as a safer alternative, typically requiring an extended hospital stay. In the mid 1980s, large-volume paracentesis was reintroduced without plasma expanders and was once again deemed a safe practice that would not cause a change in plasma volume. Abdominal imaging has replaced the practice of evaluating abdominal trauma by performing a diagnostic paracentesis.
The mechanism for the development of ascites (excess fluid accumulation in the peritoneal space) is not well understood. Cirrhosis is the leading cause of ascites in the setting of portal hypertension. Capillary pressure increases with obstruction of venous blood flow through the damaged liver. Failure of the liver to metabolize aldosterone increases sodium and water retention through the kidney. Failure of the liver to produce albumin contributes to fluid moving from the vascular space into the peritoneal space.
In addition to cirrhosis, other causes of portal hypertension include right heart failure, portal vein thrombosis, Budd-Chiari syndrome, and liver metastases.
Pancreatitis, chylous fluid accumulation, nephritic syndrome, serositis, colitis, peritoneal carcinomatosis, tuberculous peritonitis, and peritonitis may cause ascites through a different mechanism.
A 55-year-old woman with hypertension and atrial fibrillation presented to the emergency department with an increase in abdominal girth, weight gain, shortness of breath and lower extremity edema over the last several months. She denied alcohol consumption and intravenous drug use. Her medications included metoprolol and warfarin. Her vital signs revealed that she was afebrile with an oxygen saturation of 92% on room air. Her physical examination was notable for tachypnea, significant ascites, and pitting edema. Her laboratory values significant for a normal white blood cell count, an INR of 2.6 and a platelet count of 125,000/mm3. A paracentesis was performed.
- Indications: Any new onset ascites of unclear etiology needs to be tapped to determine etiology.
- Pre- procedure individual risk assessment of bleeding: Her warfarin was held and fresh frozen plasma was given. No platelets were administered as there is no evidence of a platelet cutoff in the literature.
- Procedure: A diagnostic and therapeutic paracentesis was performed ...