title: Oxymetazoline Metered Dose Spray: Factors Affecting Delivery Volume.
abstract: OBJECTIVE
  The current study compared the amount of oxymetazoline delivered by various anesthesia providers when holding the bottle in the upright and inverted position. Additionally, the amount delivered from a full bottle and a half-full bottle was also investigated.
  
  
  METHODS
  Using an analytical balance that was calibrated to zero, we evaluated the impact the position of the bottle and the volume of oxymetazoline in the bottle had on the amount being delivered by both anesthesia staff and trainees.
  
  
  RESULTS
  When using both filled and half-filled bottles, the amount delivered increased significantly when comparing the upright versus inverted position. With a full bottle, the amount delivered when the bottle was inverted increased almost 10-fold from 62 ± 80 to 606 ± 366 μL (p < 0.0001). Similarly, even with a half-filled bottle, the amount delivered increased in the inverted positions from 41 ± 48 to 645 ± 393 μL. Regardless of the scenario, we also noted significant variation from provider to provider.
  
  
  CONCLUSIONS
  Our results demonstrate that several factors may affect the amount of oxymetazoline delivered for metered dose bottles. Given the potential for severe end-organ effects with excessive dosage, alternative means of delivery are needed for its perioperative use.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Nationwide Children's Hospital, Columbus, Ohio.
authors.forename: Mumin
authors.initials: M
authors.lastname: Hakim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Nationwide Children's Hospital, Columbus, Ohio.
authors.forename: Hina
authors.initials: H
authors.lastname: Walia
authors.affiliation: Department of Anesthesiology and Pain Medicine, Nationwide Children's Hospital, Columbus, Ohio.
authors.forename: Mahmood
authors.initials: M
authors.lastname: Rafiq
authors.affiliation: Department of Anesthesiology and Pain Medicine, Nationwide Children's Hospital, Columbus, Ohio.
authors.forename: Timothy
authors.initials: T
authors.lastname: Grannell
authors.affiliation: Department of Anesthesiology and Pain Medicine, Nationwide Children's Hospital, Columbus, Ohio ; Department of Anesthesiology & Pain Medicine, The Ohio State University, Columbus, Ohio.
authors.forename: Richard S
authors.initials: RS
authors.lastname: Cartabuke
authors.affiliation: Department of Anesthesiology and Pain Medicine, Nationwide Children's Hospital, Columbus, Ohio ; Department of Anesthesiology & Pain Medicine, The Ohio State University, Columbus, Ohio.
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Tobias
keywords: hypertension; oxymetazoline; α2-adrenergic agonist