title: Reducing perceived pain levels during nonbreast lymphoscintigraphy.
abstract: OBJECTIVE
  The aim of this study was to quantify the reduction of perceived pain levels during lymphoscintigraphy for melanoma by altering the pH of the Tc-sulfur colloid to near the physiologic value of 7.40.
  
  
  METHODS
  This is an institutional review board- and Food and Drug Administration-approved randomized, double-blinded, prospective crossover trial, registered with clinicaltrials.org. Before beginning the procedure and after signing informed consent, 60 serial enrollees presenting for sentinel lymph node imaging of melanoma of the thorax and appendicular structures completed a questionnaire addressing background information, administered by a research support nurse.An investigator (N.H.) prepared the injections to be used and labeled them such that no one else could discover which injections contained standard-of-care solution and which contained the pH-altered solution (buffered to near pH 7.40 using sodium bicarbonate).After each injection, the enrollee was asked by a research support nurse to quantify the pain of each injection using a scale of 0 to 10. The injection site location (head, thorax, appendicular structures, and other) was also recorded.
  
  
  RESULTS
  Sixty subjects were enrolled in the study, of which 57 had complete data. On average, there was a significant mean (SD) decrease of 1.42 (2.17) points (95% confidence interval, 0.85-2.00) on a pain scale of 0 to 10 when the buffered injections were used as compared with the standard-of-care injections (P < 0.0001). Ordering of injections did not significantly affect perceived pain scores.
  
  
  CONCLUSIONS
  The use of sodium bicarbonate to buffer the pH of Tc-sulfur colloid to near the physiologic value of 7.40 significantly reduced perceived pain levels during nonbreast lymphoscintigraphy.
authors.affiliation: From the *Naval Medical Center San Diego, San Diego, CA; †University of Arkansas for Medical Sciences, Little Rock, AR; and ‡George Washington University, Washington, DC.
authors.forename: Mickaila J
authors.initials: MJ
authors.lastname: Johnston
authors.forename: James A
authors.initials: JA
authors.lastname: Ntambi
authors.forename: Nicki
authors.initials: N
authors.lastname: Hilliard
authors.forename: Horace J
authors.initials: HJ
authors.lastname: Spencer
authors.forename: Rita
authors.initials: R
authors.lastname: Vaughn
authors.forename: Shawna S
authors.initials: SS
authors.lastname: Owens
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Myrick
authors.forename: Larry D
authors.initials: LD
authors.lastname: Parker
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Garner
authors.forename: Tracy L
authors.initials: TL
authors.lastname: Yarbrough
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007267:Injections; D061305:Lymphoscintigraphy / Q000009:adverse effects* / Q000379:methods; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging*; D008875:Middle Aged; D010146:Pain / Q000209:etiology*; D059408:Pain Management / Q000379:methods; D019275:Radiopharmaceuticals / Q000008:administration & dosage* / Q000009:adverse effects; D013671:Technetium Tc 99m Sulfur Colloid / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D019275:Radiopharmaceuticals; D013671:Technetium Tc 99m Sulfur Colloid