Fatal Brain Injury Following Carbon Dioxide Angiography

Carbon dioxide (CO₂) as a contrast agent has been in use as early as the 1920s for visualization of retroperitoneal structures. Digital subtraction angiography (DSA) using CO₂ as a contrast agent for vascular imaging was developed in the 1980s. Currently, CO₂  angiography is an alternative agent in patients with chronic kidney disease (CKD) and those who are at risk of developing contrast-induced nephropathy. However, CO₂ causes neurotoxicity if the gas inadvertently enters the cerebrovascular circulation leading to fatal brain injury.

A 71-year-old female with h/o sickle cell trait, hypertension, obesity, metastatic renal cell cancer status post nephrectomy, bone metastasis, chronic kidney disease was admitted for elective embolization of the humerus bone metastasis. Given the high probability of contrast-induced nephropathy, CO₂ angiography was chosen for embolization of the metastasis. During the procedure, the patient became unresponsive. Emergent medical management with hyperventilation, 100% fraction oxygen inhalation was performed. Her neuroimaging showed global cerebral edema. An intracranial pressure monitor was placed which confirmed intracranial hypertension. Hyperosmolar therapy was administered with no improvement in clinical examination. She progressed to brain stem herniation. Given poor prognosis, the family opted for comfort measures and the patient expired.

Inadvertent carbon dioxide entry into cerebrovascular circulation during angiography can cause fatal brain injury. Caution must be exercised while performing CO₂  angiography in blood vessels above the diaphragm.