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The Best in FOAM Education

  • Philip Siva Vittozzi Wong, MD

How To Do It: Paracentesis

A 65 year old male with stage IV liver cancer presents with vomiting, increased jaundice, and confusion. Vitals are normal, but on physical exam you notice a distended abdomen. You order a sepsis work-up but you recognize that you need to tap that belly.

Take Home #1

In the emergency department, most of the times you will only need to do a diagnostic tap.

Grab supplies:

  1. Sterile gloves and mask

  2. Sterile OR towel or, even better, a fenestrated drape with adhesive

  3. Chlorhexidine

  4. Long 20 peripheral IV angiocatheters OR syringe + needle from a central line kit OR a spinal needle

  5. 60 cc syringe

  6. Sterile cup to collect the fluid sample

  7. Lidocaine, syringe and needle to inject lidocaine


  • Find your pocket with the ultrasound and mark it

  • Switch to the linear probe and put color on to make sure that you are not going through the epigastric vessels

  • If you do not have an ultrasound, you will have to go by clinical exam

  • Positioning:

  • Have the patient sitting up between 45% and 90 degrees

  • Roll the patient towards you a bit to allow the bowel to float up and leave the right lower quadrant free of bowel

  • The best spot is basically the right lower quadrant: 4cm superior and medial to the anterior superior iliac spine

  • Fill up a 10 cc syringe with lidocaine

  • Numb the area by making a wheal and then go straight for the peritoneum while aspirating

  • As soon as you get peritoneal fluid flashback, withdraw the needle to numb the peritoneum and keep injecting in the entire track

  • Prep with chlorhexidine

  • Place your drapes

  • Put the gloves on and tap that belly

  • Remove about 20 cc and place the peritoneal fluid in the sterile cup and send it to the lab

The Z method:

  • Right after penetrating the skin, use your other hand to pull the skin up so that the insertion site in the peritoneum and the insertion site on the skin are not aligned in the same tract. After the procedure, this will prevent leakage of peritoneal fluid

  • If you cannot use the Z method, you can always suture the hole if the leakage does not stop after the procedure is over

Take Home #2

But what if you need to do a therapeutic tap?

  • Once you have a catheter inside the belly, you can attach a 10 cc syringe

  • Remove the plunger from the syringe

  • Insert suction tubing inside the empty syringe

  • Attach the suction tubing to the wall suction canister

  • You can also use the Safe-T-Centesis kit if available

  • You will need the same supplies outlined above (7 items)

  • In addition you will need the vacuum glass bottles or you can also use the wall suction canisters

  • Remove the cap on the vacuum glass bottle before you start the procedure

  • Prep the area and place your drapes

  • Open the Safe-T-Centesis and put gloves on

  • Mount the pig tail shaped catheter onto the needle

  • Make sure that the tubing is closed off to the patient

  • You have to make a nick in the skin with the blade before the tap

  • Get peritoneal fluid flash back and slide the catheter into the belly

  • Place 20 cc of peritoneal fluid in the sterile cup if you need to send it to the lab

  • In the kit you will find tubing to remove large volume of ascites. One end of the tubing has a sharp tip which will go to the vacuum glass bottle. The other end attaches to the pig-tail catheter

  • Advantages of the Safe-T-Centesis

  • The tip is sharp when it hits resistance, it becomes blunt when there is no resistance so you don’t accidentally perforate bowel

  • Disadvantages of the Safe-T-Centesis

  • It’s cumbersome and takes more time to set up

  • ​Once you open the tray you do not have a lot of sterile space to work with, so remember to save one of your sterile towels for a sterile field

Take Home #3

What if it’s taking too long to do the therapeutic tap and you want remove several liters?

You have a few options to keep removing ascites while you go see other patients:

  • Tape the catheter to the rail of the bed so it’s suspended in mid air

  • Use tape to attach the catheter to the patient so that the catheter is suspended in mid air

  • Sandwich the catheter in between two large tegaderms so the catheter does not kink


Philip Siva Vittozzi Wong, MD is a current third year resident at Stony Brook Emergency Medicine.


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