title: Effects of humidity on foil and vial packaging to preserve glucose and lactate test strips for disaster readiness.
abstract: OBJECTIVE
  Efficient emergency and disaster response is challenged by environmental conditions exceeding test reagent storage and operating specifications. We assessed the effectiveness of vial and foil packaging in preserving point-of-care (POC) glucose and lactate test strip performance in humid conditions.
  
  
  METHODS
  Glucose and lactate test strips in both packaging were exposed to mean relative humidity of 97.0 ± 1.1% in an environmental chamber for up to 168 hours. At defined time points, stressed strips were removed and tested in pairs with unstressed strips using whole blood samples spiked to glucose concentrations of 60, 100, and 250 mg/dL (n = 20 paired measurements per level). A Wilcoxon signed rank test was used to compare stressed and unstressed test strip measurements.
  
  
  RESULTS
  Stressed glucose and lactate test strip measurements differed significantly from unstressed strips, and were inconsistent between experimental trials. Median glucose paired difference was as high as 12.5 mg/dL at the high glucose test concentration. Median lactate bias was -0.2 mmol/L. Stressed strips from vial (3) and foil (7) packaging failed to produce results.
  
  
  CONCLUSIONS
  Both packaging designs appeared to protect glucose and lactate test strips for at least 1 week of high humidity stress. Documented strip failures revealed the need for improved manufacturing process.
authors.affiliation: Point-of-Care Testing Center for Teaching and Research, Pathology and Laboratory Medicine, University of California, Davis, California.
authors.forename: Anh-Thu
authors.initials: AT
authors.lastname: Truong
authors.affiliation: Point-of-Care Testing Center for Teaching and Research, Pathology and Laboratory Medicine, University of California, Davis, California.
authors.forename: Richard F
authors.initials: RF
authors.lastname: Louie
authors.affiliation: Point-of-Care Testing Center for Teaching and Research, Pathology and Laboratory Medicine, University of California, Davis, California.
authors.forename: John H
authors.initials: JH
authors.lastname: Vy
authors.affiliation: Point-of-Care Testing Center for Teaching and Research, Pathology and Laboratory Medicine, University of California, Davis, California.
authors.forename: Corbin M
authors.initials: CM
authors.lastname: Curtis
authors.affiliation: Point-of-Care Testing Center for Teaching and Research, Pathology and Laboratory Medicine, University of California, Davis, California.
authors.forename: William J
authors.initials: WJ
authors.lastname: Ferguson
authors.affiliation: Point-of-Care Testing Center for Teaching and Research, Pathology and Laboratory Medicine, University of California, Davis, California.
authors.forename: Mandy
authors.initials: M
authors.lastname: Lam
authors.affiliation: Point-of-Care Testing Center for Teaching and Research, Pathology and Laboratory Medicine, University of California, Davis, California.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Sumner
authors.affiliation: Point-of-Care Testing Center for Teaching and Research, Pathology and Laboratory Medicine, University of California, Davis, California.
authors.forename: Gerald J
authors.initials: GJ
authors.lastname: Kost
mesh_terms: D001786:Blood Glucose; D004189:Disaster Planning; D004190:Disasters; D006813:Humidity / Q000009:adverse effects*; D019344:Lactic Acid / Q000097:blood*; D019095:Point-of-Care Systems; D011934:Reagent Strips / Q000737:chemistry*
chemical_list: D001786:Blood Glucose; D011934:Reagent Strips; D019344:Lactic Acid