title: Immediate complications of intravenous contrast for computed tomography imaging in the outpatient setting are rare.
abstract: OBJECTIVE
  Despite increasing attention to the long-term risks of radiation exposure and contrast-induced nephropathy (CIN), institutional guidelines and patient consent procedures for contrast-enhanced computed tomography (CECT) imaging in the emergency department (ED) setting have focused primarily on more immediate complications, directly attributable to the administration of intravenous (IV) iodinated contrast administration. Thus, this study sought to define the risk of these immediate complications with the overall aim of improving institutional guidelines and patient consent procedures.
  
  
  METHODS
  This was a prospective, consecutive cohort study of patients undergoing CECT of any body region in the ED, for complications occurring within 1 week of contrast administration, using predefined implicit definitions. Severe complications were defined as any of the following requiring medical or surgical intervention: bronchospasm with acute respiratory failure, airway obstruction, anaphylactoid shock, or acute pulmonary edema. The development of compartment syndrome, lactic acidosis, or pulmonary edema within 1 week of contrast administration was also considered a severe complication.
  
  
  RESULTS
  Of 633 patients, only five (0.8%, 95% confidence interval [CI] = 0.3% to 1.8%) reported any immediate complications, all of which were classified as minor. No patient developed a reaction meeting the study definition of a severe complication.
  
  
  CONCLUSIONS
  The frequency of severe, immediate complications from CECT imaging that includes IV contrast is less than 1%, and the frequency of mild complications is less than 2%. The authors conclude that CECT is associated with a very low rate of severe immediate complications.
authors.affiliation: Department of Emergency Medicine, Carolinas Medical Center, Charlotte, NC, USA.
authors.forename: Alice M
authors.initials: AM
authors.lastname: Mitchell
authors.forename: Alan E
authors.initials: AE
authors.lastname: Jones
authors.forename: James A
authors.initials: JA
authors.lastname: Tumlin
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Kline
mesh_terms: D000046:Academic Medical Centers; D058186:Acute Kidney Injury / Q000139:chemically induced / Q000453:epidemiology*; D000328:Adult; D000368:Aged; D015897:Comorbidity; D003287:Contrast Media / Q000009:adverse effects*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007455:Iodine / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009657:North Carolina / Q000453:epidemiology; D010045:Outpatients / Q000706:statistics & numerical data; D011446:Prospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000009:adverse effects*; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D007455:Iodine