Paracentesis
Encyclopedia
Paracentesis is a medical procedure involving needle drainage of fluid from a body cavity
, most commonly the peritoneal cavity
in the abdomen
.
A related procedure is thoracocentesis, which is needle drainage of the chest cavity. Pericardiocentesis
involves taking fluid in the area of the pericardium
.
Ask the patient to urinate before the procedure or use a Foley to empty the bladder. Position the patient in the bed with the head elevated at 45-60 degrees to allow fluid to accumulate in lower abdomen.. After cleaning the side of the abdomen with an antiseptic solution, physicians will numb a small area of skin and then insert a fairly large-bore needle (along with a plastic sheath) 2 to 5 cm to reach the peritoneal (ascitic) fluid. The needle is then removed, leaving the plastic sheath behind to allow drainage of the fluid. The fluid can be drained by gravity or by connection to a vacuum bottle. Up to 11 litre
s of fluid may be drained during the procedure. If fluid drainage is more than 5 litres, patients may receive intravenous serum albumin
(25% albumin, 8g/L) to prevent hypotension
(low blood pressure).
The procedure generally is not painful; patients require no sedation
. As long as they are not too dizzy and maintain their blood pressure after the procedure, they can go home afterwards.
The ascitic white blood cell count can help determine if the ascites is infected.
Body cavity
By the broadest definition, a body cavity is any fluid-filled space in a multicellular organism. However, the term usually refers to the space located between an animal’s outer covering and the outer lining of the gut cavity, where internal organs develop...
, most commonly the peritoneal cavity
Peritoneal cavity
The peritoneal cavity is a potential space between the parietal peritoneum and visceral peritoneum, that is, the two membranes that separate the organs in the abdominal cavity from the abdominal wall...
in the abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
.
A related procedure is thoracocentesis, which is needle drainage of the chest cavity. Pericardiocentesis
Pericardiocentesis
In medicine, pericardiocentesis is a procedure where fluid is aspirated from the pericardium .-Position:The patient undergoing pericardiocentesis is positioned supine with the head of the bed raised to a 30- to 60-degree angle.This places the heart in proximity to the chest wall for easier...
involves taking fluid in the area of the pericardium
Pericardium
The pericardium is a double-walled sac that contains the heart and the roots of the great vessels.-Layers:...
.
Indications
It is used for a number of reasons:- to relieve abdominal pressure from ascitesAscitesAscites is a gastroenterological term for an accumulation of fluid in the peritoneal cavity.The medical condition is also known as peritoneal cavity fluid, peritoneal fluid excess, hydroperitoneum or more archaically as abdominal dropsy. Although most commonly due to cirrhosis and severe liver...
- to diagnose spontaneous bacterial peritonitisSpontaneous bacterial peritonitisSpontaneous bacterial peritonitis is the development of peritonitis despite the absence of an obvious source for the infection. It occurs almost exclusively in people with portal hypertension , usually as a result of cirrhosis of the liver...
and other infections (e.g. abdominal TB) - to diagnose metastatic cancerCancerCancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
- to diagnose bloodBloodBlood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
in peritoneal space in trauma - to puncture the tympanicTympanitesTympanites , also known as meteorism, is a medical condition in which excess gas accumulates in the gastrointestinal tract.-Possible causes:* Bowel obstruction* Renal stones* Functional disorder* Overeating...
membrane for diagnostic purposes, such as taking a bacterial swab from the middle ear (tympanocentesis). - to reduce intra-ocular pressure in central retinal artery occlusion (oculocaentesi)and any hyphaema in the anterior chamber of the eye where blood does not get obsorbed in a week's time.
Paracentesis for Ascites
The procedure is often done in a doctor's office or an outpatient clinic. In an expert's hands, it is very safe, although there is a very small risk of introducing an infection, causing excessive bleeding or perforating a loop of bowel. Some of these risks can be minimized greatly with the use of ultrasound guidance.Ask the patient to urinate before the procedure or use a Foley to empty the bladder. Position the patient in the bed with the head elevated at 45-60 degrees to allow fluid to accumulate in lower abdomen.. After cleaning the side of the abdomen with an antiseptic solution, physicians will numb a small area of skin and then insert a fairly large-bore needle (along with a plastic sheath) 2 to 5 cm to reach the peritoneal (ascitic) fluid. The needle is then removed, leaving the plastic sheath behind to allow drainage of the fluid. The fluid can be drained by gravity or by connection to a vacuum bottle. Up to 11 litre
Litre
pic|200px|right|thumb|One litre is equivalent to this cubeEach side is 10 cm1 litre water = 1 kilogram water The litre is a metric system unit of volume equal to 1 cubic decimetre , to 1,000 cubic centimetres , and to 1/1,000 cubic metre...
s of fluid may be drained during the procedure. If fluid drainage is more than 5 litres, patients may receive intravenous serum albumin
Serum albumin
Serum albumin, often referred to simply as albumin is a protein that in humans is encoded by the ALB gene.Serum albumin is the most abundant plasma protein in mammals. Albumin is essential for maintaining the osmotic pressure needed for proper distribution of body fluids between intravascular...
(25% albumin, 8g/L) to prevent hypotension
Hypotension
In physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...
(low blood pressure).
The procedure generally is not painful; patients require no sedation
Sedation
Sedation is the reduction of irritability or agitation by administration of sedative drugs, generally to facilitate a medical procedure or diagnostic procedure...
. As long as they are not too dizzy and maintain their blood pressure after the procedure, they can go home afterwards.
Ascitic fluid analysis
The serum-ascities albumin gradient can help determine the cause of the ascites.The ascitic white blood cell count can help determine if the ascites is infected.
Contraindications
Mild hematologic abnormalities do not increase the risk of bleeding. The risk of bleeding may be increased if:- prothrombin timeProthrombin timeThe prothrombin time and its derived measures of prothrombin ratio and international normalized ratio are measures of the extrinsic pathway of coagulation. This test is also called "ProTime INR" and "INR PT". They are used to determine the clotting tendency of blood, in the measure of warfarin...
> 21 seconds - international normalized ratio > 1.6
- platelet count < 50,000 per cubic millimeter.
External links
- Paracentesis - a step-by-step procedure guide. Clinical Notes.
- WebMD: Patient guide