Diagnostic peritoneal lavage

Overview

• This invasive bedside procedure was once the gold standard for the evaluation of abdominal trauma
• DPL is highly sensitive for detecting the presence of intraperitoneal blood and organ injury in blunt abdominal trauma
• CT and ultrasound imaging, has led to a diminishing role for this procedure primarily because of low specificity and high rates of unnecessary laparotomy
• Two part procedure

1. Diagnostic peritoneal tap or aspirate (DPA)
   • A catheter is inserted into the peritoneal cavity, initially to aspirate blood or fluid.
2. Diagnostic peritoneal lavage (DPL)
   • Fluid is infused for a peritoneal lavage, if necessary.

Indications

• Evaluation to detect or rule out intraabdominal hemorrhage in a hemodynamically unstable blunt trauma patient who is unable to go to CT and when FAST is not available or technically inadequate
• Aid in the diagnosis of diaphragmatic injury in select patients.
  • Lavage fluid exiting from a chest tube is pathognomic for diaphragmatic injury
• Anterior or flank stab wounds with inconclusive local wound exploration
• Hemodynamically stable patient with tangential gunshot wounds

Contraindications

• Absolute contraindication:
  • Presence of a clear indication for immediate laparotomy
• Relative contraindications:
  • Prior abdominal operations
  • Coagulopathy
  • Advanced cirrhosis
  • Morbid obesity

Equipment Needed

• Foley catheter and nasogastric tube must be placed prior to performing DPL to avoid injuring the bladder or stomach
• Local anesthesia with 1% lidocaine with epinephrine generally provides adequate anesthesia
• Several kits are commercially available
• If not, may use tray for abdominal access for laparoscopy with a rigid peritoneal dialysis catheter

Procedure

Abdominal access

• Insertion sites
  • Infraumbilical (2 cm below) location is the standard site
  • Supraumbilical insertion site is preferred in pregnant trauma patient or in the presence of a pelvic fracture
  • Periumbilical site
• Open method
  • All three layers (skin, fascia, peritoneum) are opened under direct vision
  • Method of choice when precise insertion of the catheter is critical
    • Patient with pelvic fracture, to avoid large hematoma that may be tracking anteriorly
    • Pregnant patient
• Semi-open method
  • Fascia is opened under direct vision
  • Then Seldinger technique used where a needle is used to penetrate the peritoneum, wire passed through the needle, and the catheter is advanced over the wire.
• Closed method
  • A small nick is made through the skin
  • Then Seldinger technique used where the needle is blindly passed through the linea alba and the peritoneum
  • The wire and catheter are then inserted following the same method as above.
  • Faster, but greater risk of complications and catheter malposition
  • Avoid this method in the presence of a pelvic fracture or prior midline incision

Diagnostic peritoneal aspiration (DPA)

• Aspiration of >10mL of blood or enteric contest is considered grossly positive, instillation of the lavage fluid is not necessary

Diagnostic peritoneal lavage (DPL)

• If no fluid or <10mL fluid is aspirated, instill 1L of warm NS into abdomen, then immediately allow to drain passively
• Important not to separate catheter and tubing when transitioning from instillation to removal
• Fluid analysis is performed on a sample of the returned fluid
• Optimally, most of the liter should be returned but analysis can be performed on as little as 300 cc of the returned fluid

Diagnostic Criteria

• Blunt abdominal trauma
  • RBC >100,000/mm3
  • WBC >500/mm3
  • Elevated fluid amylase
  • Presence of enteric contents or bacteria
• Penetrating abdominal trauma
  • RBC >1000/mm3
  • WBC >500/mm3
• Results from cell analysis take 30 to 60 minutes
  • If an immediate decision is necessary, may use the density of cells in the IV tubing
  • If text can be read through the tubing it can be considered unofficially negative until the official cell counts return.
  • If the density of cells in the tubing is so high that you cannot read through it, then it can be considered a positive lavage.

Complications

• Catheter misplacement
• Hemorrhage
• Intraabdominal or retroperitoneal organ injury
• Wound infection