title: Ultrasound with topical anesthetic rapidly decreases pain of intravenous cannulation.
abstract: OBJECTIVE
  Physicians and nurses in the emergency department rarely use topical anesthesia when starting intravenous (IV) lines because of time constraints and lack of data on patients' perception of the pain associated with this procedure. Ultrasound pretreatment of skin increases permeation rates of hydrophobic topical medications, including topical lidocaine. The objective of this study was to demonstrate that ultrasound treatment followed by brief application of topical anesthetic decreases the patients' perception of the pain of IV cannulation.
  
  
  METHODS
  This was a randomized, controlled, prospective trial performed in a university hospital emergency department. Eighty-seven consecutive English-speaking, subcritically injured or ill adult patients able to give consent who were receiving an IV line as part of their care were enrolled. The intervention was a brief ultrasound treatment using the SonoPrep (Sontra Medical Corp., Franklin, MA) therapeutic ultrasound device (frequency, 53-56 kHz) followed by 5 minutes of 4% liposomal lidocaine cream and standard-care IV cannulation, or standard care alone. Participants rated their pain on a visual analog scale. Researchers assessed the site after IV insertion and 20-36 hours later. The primary outcome was participants' subjective pain score, and the secondary outcome was site skin irritation.
  
  
  RESULTS
  The ultrasound group reported significantly less pain (p<0.001), with 80% of treated participants reporting pain scores </=3 versus only 37% of controls (p <0.001).
  
  
  CONCLUSIONS
  The SonoPrep ultrasound device applied to skin for 15 seconds followed by 5 minutes of 4% liposomal lidocaine cream significantly reduced patients' perception of the pain of an IV start when compared with standard care. There were no adverse side effects noted in any participant during the 36 hours of the follow-up period.
authors.affiliation: Department of Emergency Medicine, Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903. bbecker@lifespan.org.
authors.forename: Bruce M
authors.initials: BM
authors.lastname: Becker
authors.forename: Sara
authors.initials: S
authors.lastname: Helfrich
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Baker
authors.forename: Kirsten
authors.initials: K
authors.lastname: Lovgren
authors.forename: P Allison
authors.initials: PA
authors.lastname: Minugh
authors.forename: Jason T
authors.initials: JT
authors.lastname: Machan
mesh_terms: D000293:Adolescent; D000328:Adult; D000779:Anesthetics, Local / Q000008:administration & dosage*; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000517:prevention & control*; D011446:Prospective Studies; D014464:Ultrasonic Therapy
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine