Paracentesis Technique

Advanced Ultrasound Techniques

Diagnostic versus therapeutic paracentesis

Diagnostic paracentesis saves time
- Once lidocaine needle enters the ascites, simply unscrew the lidocaine syringe, and screw on a 20ml syringe to aspirate diagnostic fluid
  - Preservatives in the Lidocaine syringe may interfere with analysis of ascites fluid and culture results
Diagnostic paracentesis may reduce complications
- The single pass of the small 22 gauge needle may reduce bleeding and ascites fluid leakage

Inoculate blood culture bottles at the bedside

Waiting for the lab to inoculate culture bottles reduces the sensitivity of SBP by 25%¹
Always obtain aerobic and anaerobic blood cultures (+/- fungal culture) bottles from the nursing supply room prior to the procedure
Wipe the tops of the bottle with an alcohol swab and inject 8-10ml into each

Ultrasound

Not mandatory, but generally considered the standard of care for paracentesis²
- US increases success rate from 65% -> 95%³
- US decrease bleeding complications⁴
Tips
- Locate largest fluid pocket⁵
  - At least 3cm
  - For small fluid pockets use a sterile probe cover and follow the needle in real-time to ensure safe entry into ascites
- After marking the skin don’t let the patient move prior to needle insertion
  - Small movements can change the bowel location in relation to the skin markings above
  - If the patient moves, reconfirm your insertion site with US
  - A sterile probe cover should be used if the area has been sterilized
- Wipe off the Gel
  - Surgical markers and sharpies immediately stop working when they come into contact with US gel
  - Use a hand towel to wipe off the gel prior to marking the skin

Poor flow of ascites

During aspiration, small bowel or omentum can occlude the bevel or the catheter ports
To improve flow
- Roll the patient towards the side of needle insertion to increase pooling of fluid around the needle
  - Pillows are helpful to support them in this position
- Pushing on the abdominal wall can increase the flow of ascites
- Briskly injecting a 10ml normal saline flush can push away loops of bowel
- Slowly withdrawing the catheter to pull it away from loops of bowel may also help flow

Don’t let the lab throw away your specimen

The lab is mandated to dispose of improperly labeled specimens
Place a patient sticker on ALL tubes of ascites including blood culture bottles
- Mark them with you initials, date, and time

References

Runyon, B.A. Management of adult patients with ascites due to cirrhosis: an update. Hepatology 49, 2087-107 (2009).
Thomsen, T.W., Shaffer, R.W., White, B. & Setnik, G.S. Videos in clinical medicine. Paracentesis. N Engl J Med 355, e21 (2006).
Nazeer, S.R., Dewbre, H. & Miller, A.H. Ultrasound-assisted paracentesis performed by emergency physicians vs the traditional technique: a prospective, randomized study. Am J Emerg Med 23, 363-7 (2005).
Mercaldi, C.J. & Lanes, S.F. Ultrasound guidance decreases complications and improves the cost of care among patients undergoing thoracentesis and paracentesis. Chest 143, 532-8 (2013).
Scheer, D., Secko, M. & Mehta, N. ACEP. http://www.acep.org/Education/Continuing-Medical-Education-(CME)/Focus-On/Focus-On–Ultrasound-Guided-Paracentesis (November, 2012).