Paracentesis

Paracentesis is the removal of fluid from the peritoneal cavity through the use of a needle for either therapy (to relieve patient symptoms) or diagnosis (to determine causes or complications of ascites). The procedure is generally well-tolerated and simple to perform, especially with the general availability of bedside ultrasound.


DIAGNOSTIC



images To analyze abnormal fluid collection in peritoneal space to determine etiology or pathologic conditions (e.g., infection). Most commonly for diagnosis of spontaneous bacterial peritonitis (SBP).


THERAPEUTIC



images To evacuate ascites for symptomatic relief, usually of shortness of breath and discomfort from abdominal distention. Paracentesis decreased in-hospital mortality 24% when done early (within 24 h of admission) as opposed to later in one large study (Orman ES et.al).


CONTRAINDICATIONS



images Absolute Contraindications


   images Disseminated intravascular coagulopathy


images Relative Contraindications


   images Intra-abdominal adhesions


   images Abdominal wall cellulitis


   images In second or third trimester pregnancy, an open supraumbilical or ultrasound-assisted approach is preferred


   images Exercise caution in coagulopathic or renal failure patients.



images General Basic Steps


   images Prepare patient


   images Anesthesia


   images Ultrasound


   images Perform procedure


   images Send for fluid analysis


LANDMARKS



images Preferred approach: 3 cm superior and medial to the anterior superior iliac spine


images Stay lateral to the rectus sheath to avoid the inferior epigastric artery. The abdominal wall is also thinner in this location.


images Alternative approach: 2 cm below the umbilicus in the midline. Avoid if the patient has a midline surgical scar.


TECHNIQUE



images Supplies


   images Bedside ultrasound machine, if available


   images Culture bottles and tubes for cell count, Gram stain, and albumin


   images Have a low threshold to send a cell count with differential, even if the tap is being performed for primarily therapeutic purposes.


   images Commercial paracentesis kits containing rigid plastic sheath cannula, if available


images If a kit is not available, then the following supplies should be obtained:


   images Iodine or chlorhexidine swabs


   images Sterile 4 × 4 gauze


   images Sterile towels or fenestrated drape


   images Sterile and nonsterile gloves


   images Sterile 60-cc syringes for collecting fluid sample


   images 10-cc syringe for anesthesia


   images 1% to 2% lidocaine (preferably with epinephrine)


   images Skin anesthesia needles


      images 25- or 27-gauge 1.5-inch needle (local anesthesia)


      images 20- or 22-gauge 1.5-inch needle (local anesthesia)


      images 18-gauge needle (inoculating specimen tubes)


   images Paracentesis needles


      images 22-gauge needle for diagnostic taps, 18-gauge needle for therapeutic taps


      images 1.5 inch should be sufficient, may need 3.5 inch (spinal needle) for obese patients


   images Adhesive bandage


images Patient Preparation


   images Direct the patient to urinate or empty the bladder via urinary catheterization


   images Ultrasonography (preferred, but not essential). Bedside ultrasonography is used to verify that the chosen site has a large fluid pocket with no bowel adhesions.


   images Sterilize the area where the needle will be inserted with copious povidone–iodine solution or similar surgical prep


   images Drape the area with sterile towels or sterile fenestrated drape


images Patient Positioning


   images If there is a large amount of ascites, the patient may be placed in a supine position with the head of the bed slightly elevated


   images Patients with lesser amounts of ascites may be placed in a lateral decubitus position for optimal pooling of fluid. Left lateral decubitus may be ideal, as this is generally the most fluid-rich area.


images Analgesia


   images Produce local anesthesia using up to 5 mg/kg of 1% lidocaine with epinephrine


   images Raise a subcutaneous wheal with a small-bore (25- or 27-gauge) needle, and then generously infiltrate the deeper tissues in the area of the paracentesis needle’s eventual passage using a longer, larger-bore needle


   images Anesthetize to the depth of the peritoneum


images Needle Insertion


   images Standard-sized (1.5-inch) metal needle will be sufficient in most cases


      images A longer (3.5-inch) spinal needle may be necessary in obese patients


      images For diagnostic taps, a smaller-gauge (22–20 gauge) needle should be utilized to decrease the chance of postprocedural fluid leak


      images For therapeutic taps, a larger (18 gauge) needle may be used to hasten fluid evacuation


   images Attach needle to a 60-mL syringe


   images Advance the needle in slow, controlled 5-mm increments with continuous gentle aspiration of the syringe. A “Z-tract” method may be employed to decrease the risk of postprocedural fluid leak (FIGURE 28.1).


      images Overlying skin is pulled by an assistant or by the non–needle bearing hand 2 cm in the caudal direction



images


FIGURE 28.1 Z-track formation and controlled removal of ascetic fluid. A: Needle insertion with caudal traction on overlying skin. B: Z-track formation after release of skin and removal of needle. (From Lane NE, Paul RI. Paracentesis. In: Henretig FM, King C, eds. Textbook of Pediatric Emergency Procedures. Philadelphia, PA: Williams & Wilkins, 1997:924, with permission.)

Only gold members can continue reading. Log In or Register to continue

Stay updated, free articles. Join our Telegram channel

Aug 9, 2016 | Posted by in EMERGENCY MEDICINE | Comments Off on Paracentesis

Full access? Get Clinical Tree

Get Clinical Tree app for offline access