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



imagesTo 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



imagesTo 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



imagesAbsolute Contraindications


   imagesDisseminated intravascular coagulopathy


imagesRelative Contraindications


   imagesIntra-abdominal adhesions


   imagesAbdominal wall cellulitis


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


   imagesExercise caution in coagulopathic or renal failure patients.



imagesGeneral Basic Steps


   imagesPrepare patient


   imagesAnesthesia


   imagesUltrasound


   imagesPerform procedure


   imagesSend for fluid analysis


LANDMARKS



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


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


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


TECHNIQUE



imagesSupplies


   imagesBedside ultrasound machine, if available


   imagesCulture bottles and tubes for cell count, Gram stain, and albumin


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


   imagesCommercial paracentesis kits containing rigid plastic sheath cannula, if available


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


   imagesIodine or chlorhexidine swabs


   imagesSterile 4 × 4 gauze


   imagesSterile towels or fenestrated drape


   imagesSterile and nonsterile gloves


   imagesSterile 60-cc syringes for collecting fluid sample


   images10-cc syringe for anesthesia


   images1% to 2% lidocaine (preferably with epinephrine)


   imagesSkin anesthesia needles


      images25- or 27-gauge 1.5-inch needle (local anesthesia)


      images20- or 22-gauge 1.5-inch needle (local anesthesia)


      images18-gauge needle (inoculating specimen tubes)


   imagesParacentesis needles


      images22-gauge needle for diagnostic taps, 18-gauge needle for therapeutic taps


      images1.5 inch should be sufficient, may need 3.5 inch (spinal needle) for obese patients


   imagesAdhesive bandage


imagesPatient Preparation


   imagesDirect the patient to urinate or empty the bladder via urinary catheterization


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


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


   imagesDrape the area with sterile towels or sterile fenestrated drape


imagesPatient Positioning


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


   imagesPatients 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.


imagesAnalgesia


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


   imagesRaise 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


   imagesAnesthetize to the depth of the peritoneum


imagesNeedle Insertion


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


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


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


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


   imagesAttach needle to a 60-mL syringe


   imagesAdvance 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).


      imagesOverlying 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.)

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

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