title: Cumulative total effective whole-body radiation dose in critically ill patients.
abstract: BACKGROUND
  Uncertainty exists about a safe dose limit to minimize radiation-induced cancer. Maximum occupational exposure is 20 mSv/y averaged over 5 years with no more than 50 mSv in any single year. Radiation exposure to the general population is less, but the average dose in the United States has doubled in the past 30 years, largely from medical radiation exposure. We hypothesized that patients in a mixed-use surgical ICU (SICU) approach or exceed this limit and that trauma patients were more likely to exceed 50 mSv because of frequent diagnostic imaging.
  
  
  METHODS
  Patients admitted into 15 predesignated SICU beds in a level I trauma center during a 30-day consecutive period were prospectively observed. Effective dose was determined using Huda's method for all radiography, CT imaging, and fluoroscopic examinations. Univariate and multivariable linear regressions were used to analyze the relationships between observed values and outcomes.
  
  
  RESULTS
  Five of 74 patients (6.8%) exceeded exposures of 50 mSv. Univariate analysis showed trauma designation, length of stay, number of CT scans, fluoroscopy minutes, and number of general radiographs were all associated with increased doses, leading to exceeding occupational exposure limits. In a multivariable analysis, only the number of CT scans and fluoroscopy minutes remained significantly associated with increased whole-body radiation dose.
  
  
  CONCLUSIONS
  Radiation levels frequently exceeded occupational exposure standards. CT imaging contributed the most exposure. Health-care providers must practice efficient stewardship of radiologic imaging in all critically ill and injured patients. Diagnostic benefit must always be weighed against the risk of cumulative radiation dose.
authors.affiliation: Department of Anesthesiology, University of Kentucky, Lexington, KY. Electronic address: Deborah.rohner@uky.edu.
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Rohner
authors.affiliation: Department of Anesthesiology, University of Cincinnati, Cincinnati, OH.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Bennett
authors.affiliation: Department of Radiology, University of Cincinnati, Cincinnati, OH.
authors.forename: Chandrasiri
authors.initials: C
authors.lastname: Samaratunga
authors.affiliation: Department of Anesthesiology, University of Michigan, Ann Arbor, MI.
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Jewell
authors.affiliation: Department of Radiology, University of Cincinnati, Cincinnati, OH.
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Smith
authors.affiliation: Department of Radiology, University of Cincinnati, Cincinnati, OH.
authors.forename: Mary
authors.initials: M
authors.lastname: Gaskill-Shipley
authors.affiliation: Department of Anesthesiology, University of Nebraska Medical Center, Omaha, NE.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Lisco
mesh_terms: D016638:Critical Illness; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology* / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects*; D011446:Prospective Studies; D011829:Radiation Dosage; D011859:Radiography; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D014916:Whole-Body Irradiation / Q000009:adverse effects*; D014947:Wounds and Injuries / Q000000981:diagnostic imaging*