Oral contrast for abdominal and pelvic CT

Background

• Oral contrast considerations for patients undergoing CT of abdomen and/or pelvis
• Pros: May add improved imaging characteristics for some patient groups
• Cons: Requires significant "lead time" (i.e. must administer >1hr prior to CT scan) and can result in delays to care

Indications for Oral Contrast

Desirable

• Suspected fistula or bowel leak
• Suspected intussusception or internal hernia

May Consider

• Suspected low-grade bowel obstruction
  • For suspected high-grade bowel obstruction, oral contrast is contra-indicated (wastes time, adds expense, can induce further patient discomfort, will not add to diagnostic accuracy, and can lead to complications, particularly vomiting and aspiration)
• Intra-abdominal abscess depending on the suspected primary source
  • May not be required if primary source is skin infection
• Metastatic evaluation
• Suspected Hernia
• Appendicitis or Diverticulitis with BMI <20
  • "Oral or rectal contrast may not be needed depending on institutional preference."
  • "Evidence is trending against the routine use of oral contrast, and particularly against the routine use of rectal contrast, for CT when IV contrast is used."

Redypaque Dose

Weight	Give 1 hour prior to scan	Give 30 minutes prior to scan	Give immediately upon arrival to CT
< 2 kg	None or as ordered by physician	None or as ordered by physician	None or as ordered by physician
2-5 kg	30 mL	30 mL	30 mL
>5-20 kg	90 mL	90 mL	90 mL
>20-50 kg	150 mL	150 mL	150 mL
>50 kg	300 mL	300 mL	300 mL

(100cc/age)/3 = dose x 3

Max = 300cc

See Also

• Contrast-induced nephropathy
• Creatinine screening prior to IV contrast