title: Preadministration of low-dose ketamine reduces tourniquet pain in healthy volunteers.
abstract: We evaluated whether preadministration of low-dose ketamine could attenuate tourniquet pain and arterial pressure increase using high tourniquet pressure in ten healthy awake volunteers. Ketamine, 0.1 mg x kg(-1), or normal saline was given intravenously in a double-blind fashion before tourniquet inflation with a pressure of 400 mmHg at the thigh. Visual analog scale (VAS) scores and systolic blood pressure (SBP) were measured at 5-min intervals. Ketamine significantly reduced VAS scores compared to saline just after tourniquet inflation [90 (64-100) mm, median (range), with saline versus 66 (50-81) mm with ketamine, P < 0.01] and at 30 min [92 (61-100) mm with saline versus 70 (50-100) mm with ketamine, P < 0.03), and significantly prolonged tourniquet time (28 +/- 6 min with saline, mean +/- SD, versus 37 +/- 7 min with ketamine, P < 0.01). SBP (120 +/- 9 mmHg) significantly increased before tourniquet deflation (133 +/- 16 mmHg) in the saline trial, but not in the ketamine trial. The results show that preadministration of low-dose ketamine attenuates tourniquet pain and arterial pressure increase during high-pressure tourniquet application and prolongs tourniquet time in healthy volunteers.
authors.affiliation: Department of Anesthesia, Nagasaki Rosai Hospital, 2-12-5 Setogoshi, Sasebo 857-0134, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Takada
authors.forename: Makoto
authors.initials: M
authors.lastname: Fukusaki
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Terao
authors.forename: Masato
authors.initials: M
authors.lastname: Kanaide
authors.forename: Kazunori
authors.initials: K
authors.lastname: Yamashita
authors.forename: Shuhei
authors.initials: S
authors.lastname: Matsumoto
authors.forename: Koji
authors.initials: K
authors.lastname: Sumikawa
mesh_terms: D000328:Adult; D004311:Double-Blind Method; D006801:Humans; D007649:Ketamine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000517:prevention & control*; D010147:Pain Measurement; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000502:physiology; D013599:Systole / Q000187:drug effects; D014111:Tourniquets / Q000009:adverse effects*
chemical_list: D016194:Receptors, N-Methyl-D-Aspartate; D007649:Ketamine