title: Evaluation of a needle-free injection system for local anaesthesia prior to venous cannulation.
abstract: We evaluated a single-use, disposable, carbon-dioxide-powered, needleless injector (J-Tip, National Medical Products Inc., CA, USA), which is claimed to deliver a virtually painless, subcutaneous injection. Seventy-two patients undergoing various types of surgery had a large-bore intravenous cannula inserted prior to induction of general anaesthesia. Three minutes beforehand, a subcutaneous injection of 0.3 ml of 1% plain lidocaine was administered. Subjects were randomly allocated to receive the lidocaine either by the needleless injector or from a conventional syringe and a 25 G needle. Pain scores were recorded on injection of the lidocaine and on insertion of the cannula. There was significantly less pain on injection with the needleless injector than with the 25 G needle (p < 0.001) but, surprisingly, there was more pain on cannulation (p < 0. 001). We conclude that the device certainly delivers a less painful subcutaneous injection than a 25 G needle, but perhaps provides less effective skin anaesthesia for venous cannulation at sites where the subcutaneous space is small; its use might be better suited to areas where the subcutaneous space is deeper.
authors.affiliation: Royal Free and University College Medical School, Room 103, 1st Floor Crosspiece, Middlesex Hospital, Mortimer Street, London W1N 8AA, UK.
authors.forename: J A
authors.initials: JA
authors.lastname: Cooper
authors.forename: L M
authors.initials: LM
authors.lastname: Bromley
authors.forename: A P
authors.initials: AP
authors.lastname: Baranowski
authors.forename: S G
authors.initials: SG
authors.lastname: Barker
mesh_terms: D000772:Anesthesia, Local / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage; D002406:Catheterization, Peripheral / Q000379:methods*; D005260:Female; D006801:Humans; D007277:Injections, Jet / Q000295:instrumentation*; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine