Observational Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Apr 28, 2016; 8(4): 419-427
Published online Apr 28, 2016. doi: 10.4329/wjr.v8.i4.419
Cumulative radiation exposure from diagnostic imaging in intensive care unit patients
Fiachra Moloney, Daniel Fama, Maria Twomey, Ruth O’Leary, Conor Houlihane, Kevin P Murphy, Siobhan B O’Neill, Owen J O’Connor, Dorothy Breen, Michael M Maher
Fiachra Moloney, Daniel Fama, Maria Twomey, Kevin P Murphy, Siobhan B O’Neill, Owen J O’Connor, Michael M Maher, Department of Radiology, Cork University Hospital, Wilton, 014 Cork, Ireland
Ruth O’Leary, Conor Houlihane, Dorothy Breen, Department of Anesthesia, Cork University Hospital, Wilton, 014 Cork, Ireland
Author contributions: Moloney F was the primary author and drafted the manuscript; Fama D, Twomey M and O’Neill SB conducted the literature review and drafted sections of the manuscript; O’Leary R, Murphy K and Houlihane C collected the data; O’Connor OJ, Breen D and Maher MM edited the manuscript.
Institutional review board statement: The study received institutional board approval from the Cork Clinical Research Ethics Committee, Lancaster Hall, 6 Little Hanover Street, Cork, Ireland.
Informed consent statement: Informed consent was not deemed necessary for this study. Clinical and radiological data was collected prospectively in an anonymised fashion and no patient underwent additional procedures or investigations as a result of inclusion in the study. No potential risks to patients were identified. The clinical research ethics committee granted approval for the study without a requirement of consent from each patient.
Conflict-of-interest statement: All authors declare no conflicts of interest.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at fiachramoloney@hotmail.com.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Fiachra Moloney, MD, Department of Radiology, Cork University Hospital, Corcaigh, Wilton, 014 Cork, Ireland. fiachramoloney@hotmail.com
Telephone: +35-321-4922000 Fax: +35-321-4922002
Received: September 25, 2015
Peer-review started: October 6, 2015
First decision: November 24, 2015
Revised: December 3, 2015
Accepted: January 29, 2016
Article in press: January 31, 2016
Published online: April 28, 2016
Abstract

AIM: To quantify cumulative effective dose of intensive care unit (ICU) patients attributable to diagnostic imaging.

METHODS: This was a prospective, interdisciplinary study conducted in the ICU of a large tertiary referral and level 1 trauma center. Demographic and clinical data including age, gender, date of ICU admission, primary reason for ICU admission, APACHE II score, length of stay, number of days intubated, date of death or discharge, and re-admission data was collected on all patients admitted over a 1-year period. The overall radiation exposure was quantified by the cumulative effective radiation dose (CED) in millisieverts (mSv) and calculated using reference effective doses published by the United Kingdom National Radiation Protection Board. Pediatric patients were selected for subgroup-analysis.

RESULTS: A total of 2737 studies were performed in 421 patients. The total CED was 1704 mSv with a median CED of 1.5 mSv (IQR 0.04-6.6 mSv). Total CED in pediatric patients was 74.6 mSv with a median CED of 0.07 mSv (IQR 0.01-4.7 mSv). Chest radiography was the most commonly performed examination accounting for 83% of all studies but only 2.7% of total CED. Computed tomography (CT) accounted for 16% of all studies performed and contributed 97% of total CED. Trauma patients received a statistically significant higher dose [median CED 7.7 mSv (IQR 3.5-13.8 mSv)] than medical [median CED 1.4 mSv (IQR 0.05-5.4 mSv)] and surgical [median CED 1.6 mSv (IQR 0.04-7.5 mSv)] patients. Length of stay in ICU [OR = 1.12 (95%CI: 1.079-1.157)] was identified as an independent predictor of receiving a CED greater than 15 mSv.

CONCLUSION: Trauma patients and patients with extended ICU admission times are at increased risk of higher CEDs. CED should be minimized where feasible, especially in young patients.

Keywords: Cumulative effective dose, Pediatric patients, Computed tomography, Radiation dose, Intensive care unit

Core tip: We hypothesized that intensive care unit (ICU) patients, especially pediatric patients, are potentially vulnerable to increased cumulative effective doses (CED) from ionizing radiation. We found a relatively low CED in the majority of ICU patients, during their stay in the ICU. Nevertheless, physicians are beholden to keep radiation exposures from diagnostic imaging as low as reasonably practical and CED should be minimized where feasible, especially in young patients. Physicians should be aware that trauma patients and patients with extended ICU admission times are at an increased risk of high CEDs.