Wound Hygiene Practices After Total Knee Arthroplasty: Does It Matter?

BACKGROUND: Current literature is limited with regard to standardized postoperative surgical site hygiene after total knee arthroplasty (TKA). With little guidance from the literature, the timing of permissible postoperative cleaning is a decision made by the individual surgeon using anecdotal evidence. A standardized wound care regimen is of particular interest to minimize the risk of infection. METHODS: To examine what species of bacteria recolonize the surgical site postoperatively, a randomized controlled trial was performed of 16 TKA patients who were allowed to shower at 2 days postoperatively and of 16 patients who were asked to wait until 2 weeks postoperatively before showering after TKA. Culture swabs of skin adjacent to the incision were performed preoperatively, just after incision closure, at dressing removal, and at 2 weeks postoperatively. Bacteria were speciated and compared between groups. A swab of the contralateral knee was performed at 2 weeks as a control. A survey of patient's preference regarding early and late showering was also carried out. RESULTS: No difference was found between the groups in rate of colonization or bacterial type, and no patients developed infection. Patients overwhelmingly preferred early showering rather than late (P = .28-.99). CONCLUSION: There is no difference in surgical site bacterial recolonization between early and delayed showering after primary TKA.

Glutamatergic effects of divalproex in adolescents with mania: a proton magnetic resonance spectroscopy study.

OBJECTIVES: This study used proton magnetic resonance spectroscopy ((1)H MRS) to evaluate the in vivo effects of extended-release divalproex sodium on the glutamatergic system in adolescents with bipolar disorder, and to identify baseline neurochemical predictors of clinical remission. METHOD: Adolescents with bipolar disorder who were experiencing a manic or mixed episode (N = 25) were treated with open-label, extended-release divalproex (serum levels 85-125 µg/mL) and underwent (1)H MRS scanning at baseline (before treatment) and on days 7 and 28. Healthy comparison subjects (n = 15) also underwent (1)H MRS scanning at the same time points. Glutamate (Glu) and glutamate+glutamine (Glx) concentrations were measured in three voxels: anterior cingulate cortex (ACC), left ventrolateral prefrontal cortex (LVLPFC), and right ventrolateral prefrontal cortex (RVLPFC), and were compared between bipolar and healthy subjects. Within the bipolar subjects, Glu and Glx concentrations at baseline and each time point were also compared between remitters and nonremitters after divalproex treatment. RESULTS: At baseline, no differences in Glu or Glx concentrations between bipolar and healthy subjects were observed. Group (HC vs. BP) by time effects revealed an interaction for Glu in the ACC, and change over time effects for Glx were noted in the ACC in patients with bipolar disorder (increase from day 0 to day 7 and then a decrease from day 7 to day 28) but not in HC. Remitters had significantly lower baseline Glx concentrations in LVLPFC, and in remitters the change in LVLPFC Glu correlated with the change in YMRS score. CONCLUSIONS: Successful treatment of mania with divalproex may be predicted by lower baseline concentrations of Glx in the LVLPFC. In addition, in remitters, the degree of symptomatic improvement is related to the change in Glu concentrations in this region, suggesting that divalproex may work via modulation of the prefrontal glutamatergic system in youth with bipolar disorder.

Docosahexaenoic acid supplementation increases prefrontal cortex activation during sustained attention in healthy boys: a placebo-controlled, dose-ranging, functional magnetic resonance imaging study.

BACKGROUND: Emerging evidence suggests that docosahexaenoic acid (DHA, 22:6n-3), the principal omega-3 (n-3) fatty acid in brain gray matter, positively regulates cortical metabolic function and cognitive development. However, the effects of DHA supplementation on functional cortical activity in human subjects are unknown. OBJECTIVE: The objective was to determine the effects of DHA supplementation on functional cortical activity during sustained attention in human subjects. DESIGN: Healthy boys aged 8-10 y (n = 33) were randomly assigned to receive placebo or 1 of 2 doses of DHA (400 or 1200 mg/d) for 8 wk. Relative changes in cortical activation patterns during sustained attention at baseline and endpoint were determined by functional magnetic resonance imaging. RESULTS: At 8 wk, erythrocyte membrane DHA composition increased significantly from baseline in subjects who received low-dose (by 47%) or high-dose (by 70%) DHA but not in those who received placebo (-11%). During sustained attention, both DHA dose groups had significantly greater changes from baseline in activation of the dorsolateral prefrontal cortex than did the placebo group, and the low-dose and high-dose DHA groups had greater decreases in the occipital cortex and cerebellar cortex, respectively. Relative to low-dose DHA, high-dose DHA resulted in greater decreases in activation of bilateral cerebellum. The erythrocyte DHA composition was positively correlated with dorsolateral prefrontal cortex activation and was inversely correlated with reaction time, at baseline and endpoint. CONCLUSION: Dietary DHA intake and associated elevations in erythrocyte DHA composition are associated with alterations in functional activity in cortical attention networks during sustained attention in healthy boys. This trial was registered at clinicaltrials.gov as NCT00662142.