1.       Introduction

Venous Air Embolism (VAE) is a rare diagnosed complication of contrast-enhanced imaging technique but could have serious outcomes. Injection of large amounts of air into the venous system may result in air hunger, dyspnea, cough, chest pain, pulmonary edema, tachycardia, hypotension, or expiratory wheezing. Neurologic deficits may result from stroke due to decreased cardiac output or paradoxical air embolism. Patients with right-to-left intracardiac shunts or pulmonary arteriovenous malformations are at a higher risk of having a neurological deficit develop from small volumes of air embolism [1]. VAE is usually seen when contrast media injection performed manually, but usage of power injection minimizes the risk. Power injectors are routinely used medical devices which can be programmed to deliver specific amounts of contrast agent at specific flow rates.

On Computerized Tomography (CT), VAE is generally recognised as air bubbles or air-fluid levels in the vascular spaces or in right ventricle and can be seen in intracranial venous system [1].

The purpose of this case is to raise awareness of considering this rare situation in patients performed Contrast Enhanced Computerized Tomography (CECT).

2.       Case Presentation

Thirty-one years old male patient was admitted to Emergency Department (ED) after a head on car collision. The patient got stuck in the car for approximately one hour. The patient was confused under the influence of alcohol and his vital signs were as follows: Glasgow Coma Scale 14 (E4V4M6), blood pressure: 132/68 mmHg, pulse rate: 75 beats/minute, respiratory rate 16 breaths/minute, temperature 36.7°C, oxygen saturation %94 on room air and blood sugar 110 mg/dl checked by glucose test strip.

The patient complained of pain localised on posterior of left hemithorax and left mid-axillary region. First physical examination and Focused Assessment with Sonography for Trauma (FAST) had no specific findings except rib tenderness on the left hemithorax and abdominal tenderness. CECT scan of chest, abdomen and brain was performed. CT scan showed fractures on the left sixth and eleventh ribs, heterogeneous splenic enhancement with perisplenic fluid and air embolism in the pulmonary artery (Figure 1). Measured volume of the air was approximately 3 cc.

After air embolism was identified, patient was placed on left lateral decubitus and Trandelenburg position and given 100% oxygen. Patient was consulted with cardiovascular surgeon. No surgical approach was considered. Therefore, patient was admitted to the ED for close observation and follow-up.Laboratory results including complete blood count, serum electrolytes, coagulation parameters, and cardiac markers werenot revealed any serious acute pathology (Table 1)

Control CT scans had performed at first and eighth hours. Air embolism was totally resolved at the eighth hour control scan (Figures 2 and 3). The patient had no symptoms during observation and discharged from ED after 24 hours without any complications related VAE or trauma

3.       Discussion

The clinical manifestations of VAE include acute dyspnea, continuous cough, chest pain, seizures or stroke. Hypoxia, tachycardia, tachypnea, hypotension are major findings. Unintentionally injection of 200-300 cc of air to the vascular system has been reported as fatal [2]. Treatment includes 100% oxygen and placing the patient in the left lateral decubitus and Trandelenburg position. Hyperbaric oxygen could be used to reduce the size of air bubbles. Cardiopulmonary resuscitation should be started immediately if cardiopulmonary arrest occurs [1].

VAE related to CECT examination have been reported between 7% - 23% in different studies [3-5].

Although those studies show significant ratio of iatrogenic VAE, limited cases reported in the literature shows VAE after CECT scan [6]. Probably; most of the patients are clinically asymptomatic and often undiagnosed. In this case the patient did not have any symptoms or life threatening findings related to VAE during the treatment as usual.

4.       Conclusion

Physicians and also CT technicians should be aware of VAE in patients whom performed CECT and be ready to manage its complications.

Table 1: Routine Emergency Tests of the Patient.

1.       ACR Committee on DrugsandContrast Media. ACR Manual on Contrast MediaVersion 10.1AmericanCollege of Radiology, USA.

2.       Toung TJ, Rossberg MI, Hutchins GM (2001) Volume of Air in a Lethal Venous Air Embolism. Anesthesiology; 94: 360-361.

3.       Woodring JH, Fried AM (1988) Nonfatalvenous airembolism after contrast-enhanced CT. Radiology 167: 405-407.

4.       Sodhi KS, Saxena AK, Chandrashekhar G, Bhatia A, Singhi S, et. al. (2015) Vascular air embolism after contrast administration on 64 row multipled etector computed tomography: A prospectiveanalysis. LungIndia 32: 216-219.

5.       Groell R, Schaffler GJ, RienmuellerR, Kern R (1997) Vascular air embolism: location, frequency, andcause on electron-beam CT studiesof thechest. Radiology 202: 459-462.

6.       Ball CG, Rajani RR, Feliciano DV, Nicholas JM (2009) Venous airemboliand computed axialtomography power contrast injectors. Am J Surg 197: 57–58.