Risk of ionizing radiation exposure from CT scans in the Neuro ICU - a patient safety blind spot?

Introduction : The exposure to ionizing radiation has increased significantly with the wide availability of computed tomography (CT) scans and portable imaging technology. We examine the pattern of use of inpatient diagnostic imaging and radiation exposure in the neuro-intensive care unit (Neuro ICU, N-ICU) patient population at a large academic medical center. Methods : We retrospectively evaluated all patients admitted to the Neuro ICU at our academic medical center from January 1 to December 31, 2013. The number and type of CT studies was collected, and the corresponding estimated radiation dose was calculated. We limited the evaluation to CT scans, which accounts for the majority of radiation exposure. Data were electronically collected and cross-referenced to the patients’ electronic medical records (EMR) and radiology records. Radiation dose estimates were calculated based on published reference values and conversion factors (CT head (2mSv)), CT angiography of the head and neck (7-10 mSv), Ct Chest /Abd/pelvis ( 10 mSv), CT cerebral perfusion analysis (3.3 mSv). Results: In the calendar year 2013, we had a total of 2353 admission encounters (F=1078). The mean age on admission was 56.55Y ± 16.7. The mean length of ICU stay was 6.3 days. Mechanical ventilation was initiated on 420 patients with a mean length on mechanical ventilation 5.09 days. 2028 CT scans were completed of which approximately 60% were head CT without contrast (n=1209). 379 patients had multiple CT studies. The mean number of studies was 3.8 ± 2. The number of patients with more thanthree3 studies during their ICU stay was 159. The maximum number of studies on a single patient was 21. Conclusion: Patients in the Neuro ICU are at a risk for significant exposure to ionizing radiation. Radiation exposure must be factored into the culture of quality and patient safety in the ICU.