Vascular air embolism after contrast administration on 64 row multiple detector computed tomography: A prospective analysis

Abstract

Background:Vascular air embolism is being progressively reported as a nonfatal event with increase in use of computed tomography (CT) as a diagnostic modality. This study was undertaken to study the frequency and site of vascular air embolism in patients undergoing contrast-enhanced CT (CECT) and analyze CT parameters that influence its prevalence and final outcome.Materials and Methods:This was a prospective study approved by departmental ethics committee. Presence and location of air emboli in 200 patients who underwent CT scan of chest on a 64 detector scanner was recorded. We analyzed the role of various factors that could influence the prevalence of air embolism after injection of contrast in CECT scans. These factors included the amount of contrast injected, rate of flow of injection of contrast, site of injection of contrast, and size of intravenous access line.Results:Iatrogenic vascular air emboli were seen in 14 patients (7% of total). The locations of air emboli were main pulmonary artery in 12 (6% of total), left brachiocephalic vein in 3 (1.5% of total), right atrial appendage in 4 (2% of total), and superior vena cava (SVC) in 1 (0.5%) patient. There was no association between volume of contrast, flow rate, site and size of intravenous access, and presence of air emboli.Conclusion:Radiologists as well as referring physicians should be aware of vascular air embolism, which can occur after contrast injection in patients undergoing CT scan. Age, volume of contrast, flow rate of pressure injector, and site and size of venous cannula do not influence the likelihood or incidence of detection of venous air emboli on CT scans.

Pulmonary Air embolism Associated with Pneumocephalus: A Case Report

“…In clinical scenarios involving contrast enhanced studies with power injectors, the risk for retrograde cerebral venous air embolism is likely increased [6]. A prospective study from India examined the risks of air embolism in 200 patients that underwent contrast enhanced CT and found that iatrogenic air embolism occurred in 7% of all studies [7].…”

Multiple asymptomatic vascular air embolisms following contrast-enhanced CT scan

“…Studies on non-fatal iatrogenic air embolism following a CECT examination are limited. Most iatrogenic air emboli were reported as being small in size (defined as less than 1 cm) 2–4. Compared with large air embolism, such small air embolism is usually asymptomatic and non-fatal.…”

“…The most common location of VAE is the main pulmonary artery (5.52%), followed by right atrial appendage (2.2%), left brachiocephalic vein (1.65%) and superior vena cava (0.55%),2 4 4 as air bubbles tend to rise within the most non-dependent areas in a vessel or cardiac chamber contributed by the buoyancy of air in a fluid medium. Although rapid injection of air amounting to 100–200 mL has been shown to raise the mortality risk following cardiopulmonary arrest,2 another study showed no association between the presence of air emboli and the volume of contrast, flow rate, site and the size of intravenous access 4. However, the duration of persistence of air embolism at different vasculature is unclear as there is no literature available about the topic.…”

“…Incidence of VAE following CECT has been reported to be 11.7%–23% 2 3. However, a fairly recent prospective study reported a much lower incidence of 7% 4…”

Iatrogenic peripheral pulmonary air embolism following intravenous contrast administration for CT pulmonary angiography: proposal of the “double bronchus sign”

“…The frequency of central vascular air embolism has demonstrated no relationship to technical factors such as contrast flow rate, site and size of peripheral cannula, neither in the study by Groell et al nor in a more recent, similar study of 200 patients. 2 …”