Vicarious Contrast Excretion to the Gastrointestinal Tract in a Critically Ill Hypotensive Patient: A Diagnostic Dilemma in Intensive Care

Vicarious contrast excretion, a rare phenomenon, involves the excretion of intravascular contrast material through non-urinary routes. This atypical occurrence can lead to unexpected findings on imaging studies, causing diagnostic challenges. We present a case of a 62-year-old obese lady with a complex medical history, including diabetes mellitus, hypertension, bronchial asthma, and osteoarthritis, who presented with a right-sided popliteal deep vein thrombosis (DVT). Sudden onset dyspnea and desaturation raised suspicion of pulmonary embolism, prompting contrast-enhanced computed tomography pulmonary angiography (CTPA). The patient was electively intubated and was hypotensive following the event. Due to difficult intravenous access, bilateral external jugular veins were utilized for contrast administration initially on the right side, followed by the left side. However, extravasation occurred from both sides, leading to suboptimal CTPA images. Non-contrast computed tomography was performed, revealing contrast in the gastrointestinal tract from the stomach up to the distal colon. Endoscopy ruled out perforation. Subsequent non-contrast scan replicated the phenomenon, with delayed clearance of contrast from luminal surfaces, without any major pathology, confirming the diagnosis of vicarious contrast excretion. The patient was later managed as a respiratory tract infection with septic shock and discharged to the ward. Vicarious contrast excretion poses a diagnostic conundrum, particularly in patients with comorbidities complicating standard imaging protocols. Extravasation of contract media, hypotension and renal impairment are risk factors for its development. This rare complication altered the diagnostic pathway, emphasizing the importance of considering alternative excretion routes in challenging cases.