Cerebral Venous Air Embolism: A Rare Phenomenon

Abstract

Cerebral venous air embolism (CVAE) is an extremely rare phenomenon. Most reports of cerebral air embolism focus on the arterial territory, and consequently CVAE has remained poorly understood, especially regarding its pathophysiology and treatment. The authors describe an elderly male patient who was admitted through the Emergency Department with subacute confusion. A brain computed tomography (CT) showed multiple cerebral venous gas emboli. No potential causes were found apart from previous peripheral vein cannulation and intravenous medication administration. The patient received supportive treatment, with complete radiological resolution of the gas emboli, while maintaining his previous confusional state. The aim of this report is to highlight a rare and understudied entity, and discuss its causes, proposed pathophysiology and appropriate management.

Paradoxical and Retrograde Air Embolism from Pressurized Peripheral Bolus

“…The proposed mechanism for the venous air emboli is less certain, but was thought to be secondary to severe tricuspid regurgitation driving retrograde pressure into the superior vena cava and subsequent jugular veins ( Figure 3 ). The lack of valves in the jugular veins allows the air to enter the venous circulation more easily [ 19 ]. This phenomenon is thought to be underestimated in the reported literature.…”

“…is phenomenon is thought to be underestimated in the reported literature. Additional reported pertinent factors include smaller bubble size, lower specific gravity of air compared to blood, vein diameter, cardiac output, and increased intrathoracic pressure [2,[19][20][21][22]. Further suggested pathophysiology is whereby venous gas emboli enter the pulmonary arterial circulation causing increased afterload and subsequent strain of the right heart leading to reduced preload of the left heart causing overall cardiovascular collapse resulting in hypotension and hypoxemia.…”

Incidental findings of soft tissue gas in canine and feline thoracic computed tomographic examinations

“…Anecdotally, at the authors’ institution, gas has been identified within the vasculature of the forelimbs, hindlimbs, axilla, inguinal region, mediastinum, and vertebral canal of small animal patients undergoing CT examination. The etiology of iatrogenic or pathogenic extra‐ and intravascular gas found on CT examinations has been explored in depth in human medicine 1–6 . However, there is scant literature in veterinary medicine reporting intravascular gas without an iatrogenic cause, with one study reporting intravascular gas in sea turtles with decompression sickness 7 .…”

“…The etiology of iatrogenic or pathogenic extra-and intravascular gas found on CT examinations has been explored in depth in human medicine. [1][2][3][4][5][6] However, there is scant literature in veterinary medicine reporting intravascular gas without an iatrogenic cause, with one study reporting intravascular gas in sea turtles with decompression sickness. 7 No reports of intravascular or fascial plane gas on routine CT examinations of dogs or cats without a clear or defined cause were identified in a literature search (CAB direct, PubMed, Web of Science).…”

Air on the brain: Cerebral embolism associated with outpatient line

“…Air embolism may occur in conjunction with trauma, diving accidents, hemodialysis, cardiopulmonary bypass surgery, neurosurgery, thoracic biopsies, or transpulmonary passage from barotrauma, but it is most often associated with central venous catheter (CVC) insertions [1]. Arterial air embolisms, particularly cerebral air embolisms, are a rare and potentially fatal event that may result in severe, irreversible neurological deficits [2]. High index of suspicion is necessary, especially in those with an underlying cardiac defect such as a patent foramen ovale (PFO), where a paradoxical embolism may occur.…”