The work described in this paper provides an evaluation of an aged pervious concrete pavement in the Northeastern United States to provide a better understanding of the long-lasting effects of placement techniques as well as the long-term field performance of porous pavement, specifically in areas susceptible to freezing and thawing. Multiple samples were taken from the existing pavement and were examined in terms of porosity and unit weight, compressive and splitting tensile strength, and the depth and degree of clogging. It was concluded that improper placement and curing led to uneven pavement thickness, irregular pore distribution within the pervious concrete, and highly variable strength values across the site, as well as sealed surfaces that prevented infiltration.

Background and objectivesA common analgesic technique for total knee arthroplasty (TKA) is to inject local anesthetic into the periarticular tissue during surgery, known as local infiltration analgesia (LIA). Since the solution used typically contains a large amount of local anesthetic, concerns arise about exceeding the maximum dosage when adding a peripheral nerve block. Little research exists that addresses serum ropivacaine concentrations following LIA combined with peripheral nerve block. We hypothesized that after combining LIA and adductor canal blockade (ACB), serum ropivacaine concentrations would remain below levels associated with local anesthetic toxicity.MethodsThis was a prospective observational study that included 14 subjects undergoing TKA with intraoperative LIA containing 270 mg ropivacaine with epinephrine. Patients weighing less than 80 kg were excluded due to standardized dosing by our pharmacy. Seven patients were assigned consecutively to receive LIA alone (Group LIA) and seven were assigned to receive LIA plus ACB with 100 mg ropivacaine with epinephrine (Group LIA+ACB). Venous serum ropivacaine concentrations were measured over 24 hours.ResultsPeak serum concentrations (Cmax) in Group LIA ranged from 0.23 to 0.75 µg/mL and occurred at times from 4 to 24 hours. Cmax in Group LIA+ACB ranged from 0.46 to 1.00 µg/mL and occurred at times from 4 to 8 hours. No participants demonstrated signs or symptoms of local anesthetic toxicity.ConclusionsTotal serum concentration of ropivacaine after LIA using 270 mg ropivacaine with and without an additional 100 mg perineural ropivacaine remained well below the toxicity threshold of 3.0 µg/mL at all time points. Additional studies are needed to ascertain the safety of combining LIA with peripheral nerve blockade.

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