title: Serum and wound drain ropivacaine concentrations after wound infiltration in joint arthroplasty.
abstract: Ropivacaine blood and drain levels were measured in 20 hip and 15 total knee arthroplasties after intraoperative wound infiltration with 150 to 200 mL (360-400 mg) of ropivacaine, followed by a 48-hour intra-articular pain pump infusion of 1000 mg (knees) and 300 mg (hips) commencing 12 hours postoperatively. Concentrations were below 2 microg/mL over the first 12 hours before the pain pump increased levels. Peak total ropivacaine concentration ranged from 0.65 to 4.36 microg/mL with the pain pump. The high infiltration doses produced levels below or within the safe threshold of 1 to 3 microg/mL. Pain pump infusion produced some C(max) levels above 3.0 microg/mL, but there was no clinical evidence of toxicity. Wound drain amounts (0.53-26.69 mg) indicate reinfusion should be safe, although further study is needed to confirm this.
authors.affiliation: Barwon Anaesthetic Service, Geelong, Victoria, Australia.
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Stringer
authors.forename: Aloke K
authors.initials: AK
authors.lastname: Singhania
authors.forename: Joe E
authors.initials: JE
authors.lastname: Sudhakar
authors.forename: Rodney B
authors.initials: RB
authors.lastname: Brink
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000577:Amides / Q000008:administration & dosage / Q000032:analysis* / Q000097:blood; D000779:Anesthetics, Local / Q000032:analysis* / Q000097:blood; D019644:Arthroplasty, Replacement, Hip; D019645:Arthroplasty, Replacement, Knee; D004322:Drainage; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D000077212:Ropivacaine; D013997:Time Factors