The Impact of Antibiotic-Loaded Bone Cement on Antibiotic Resistance in Periprosthetic Knee Infections

Background@#Antibiotic-loaded bone cement (ALBC) is commonly used in total knee arthroplasty (TKA), especially among high-risk patients. While previous studies have reported on the efficacy of ALBC in reducing the rate of periprosthetic joint infection (PJI), its impact on antibiotic resistance has not been determined. The purpose of this study was to investigate antibiotic resistance among organisms causing PJIs after TKA in which ALBC was utilized. @*Methods@#A retrospective review from December 1998 through December 2017 identified 36 PJIs that met inclusion criteria. Patients with culture-negative infection and unknown cement type were excluded. Patient characteristics, infecting organism, and antibiotic susceptibilities were recorded. ABLC included an aminoglycoside in all cases. @*Results@#There was no difference in the type of PJI between the 2 groups. Staphylococcus species was the most commonly isolated, with 9 of 16 cases (56.3%) using non-ALBC and 14 of 20 (65.0%) cases using ALBC. Of those infected with Staphylococcus, there was no significant difference in antibiotic susceptibilities between groups. Overall, there were only 3 cases where the infecting organism was aminoglycoside resistant (standard cement, 1; ALBC, 2). @*Conclusions@#These results suggest that the use of ALBC does not increase the risk of antibiotic resistance or affect the pattern of infection, even as the use of ALBC continues to increase, particularly among high-risk patients.

ART access-related barriers faced by HIV-positive persons linked to care in southern Ghana: a mixed method study.

BACKGROUND: Timely and enduring access to antiretroviral therapy (ART) by HIV-infected individuals has been shown to substantially reduce HIV transmission risk, HIV-related morbidity and mortality. However, there is evidence that in addition to limited supply of antiretrovirals (ARVs) and linkage to ART in many low-income countries, HIV+ persons often encounter barriers in accessing ART-related services even in contexts where these services are freely available. In Ghana, limited research evidence exists regarding the barriers HIV+ persons already linked to ART face. This paper explores ART access-related barriers that HIV+ persons linked to care in southern Ghana face. METHODS: A mixed method study design, involving a cross-sectional survey and qualitative in-depth interviews, was conducted to collect data from four healthcare providers and a total of 540 adult HIV+ persons receiving ART at four treatment centres in Ghana. We used univariate analysis to generate descriptive tabulations for key variables from the survey. Data from qualitative in-depth interviews were thematically analysed. Results from the survey and in-depth interviews were brought together to illuminate the challenges of the HIV+ persons. RESULTS: All (100%) the HIV+ persons interviewed were ARV-exposed and linked to ART. Reasons for taking ARVs ranged from beliefs that they will suppress the HIV virus, desire to maintain good health and prolong life, and desire to prevent infection in unborn children, desire both to avoid death and to become good therapeutic citizens (abide by doctors' advice). Despite this, more than half of the study participants (63.3%) reported seven major factors as barriers hindering access to ART. These were high financial costs associated with accessing and receiving ART (26%), delays associated with receiving care from treatment centres (24%), shortage of drugs and other commodities (23%), stigma (8.8%), fear of side effects of taking ARVs (7.9%), job insecurity arising from regular leave of absence to receive ART (5.3%), and long distance to treatment centres (4.9%). CONCLUSIONS: The results in this study suggest that efforts to provide and scale-up ART to all HIV+ persons must be accompanied by interventions that address structural and individual level access barriers.

Treatment of experimental verapamil poisoning with levosimendan utilizing a rodent model of drug toxicity.

BACKGROUND: Levosimendan is an inotropic agent used in the treatment of heart failure. It is a myocardial calcium sensitizer, binding to cardiac troponin-C, and a vascular K+ATP-channel agonist producing peripheral vasodilatation. AIMS: To assess the effect of levosimendan on cardiac output (CO), blood pressure (BP), and heart rate (HR) in a rodent model of severe verapamil poisoning. METHODS: Male Wistar rats were anesthetized, ventilated, and canulated with jugular and femoral venous catheters and a femoral arterial catheter. CO, systolic BP, MAP, and HR were recorded. Verapamil was infused at 6 mg/kg/h until MAP dropped to 50% of baseline (time-0) and then reduced to 4 mg/kg/h. There were five treatment groups (n = 7 per group): 1) normal saline infusion (control); 2) CaCl2 loading dose and infusion (CaCl2); 3) levosimendan 24 microgram/kg loading dose and 0.6 microgram/kg/min infusion (Levo-24); 4) levosimendan 6 microgram/kg loading dose and 0.4 microgram/kg/min infusion (Levo-6); and 5) levosimendan 0.4 microgram/kg/min infusion with concurrent CaCl2 loading dose and infusion (Levo + CaCl2). Hemodynamic parameters were recorded for 70 minutes. Primary outcome measures were changes observed in CO, BP, and HR with treatments compared to control. Secondary outcome measure was survival. Results were analyzed using one-way ANOVA with Dunnet's post-test comparison with the control group. RESULTS: All groups had similar BP, HR, and CO at base line and peak toxicity. The control group's HR, BP, and CO progressively fell during the verapamil infusion. Levo-24, Levo + CaCl2, and CaCl2 maintained CO compared with control from t = 20 min and Levo6 from t = 30 min (p < 0.05). CaCl2 (from t = 10 min) and Levo + CaCl2 (from t = 20 min) produced significant improvements in BP compared to control. However, BP did not return to pre-toxicity levels. Levo-6 and Levo-24 groups did not recover from the hypotension seen at pre-treatment maximal toxicity. HR was maintained in all treatment groups compared to control animals. Twenty-nine percent (2/7) of control, 86% (6/7) levosimendan, 100% (7/7) CaCl2, and Levo + CaCl2 animals survived to the end of the protocol. CONCLUSIONS: Levosimendan increased CO in this model of verapamil poisoning to a similar degree as CaCl2 alone, but it did not improve BP from time of maximal toxicity. The addition of CaCl2 to Levosimendan did not appear to result in any further improvement in CO and BP compared to CaCl2 alone. The failure of levosimendan to improve BP may result from vasodilation induced by levosimendan peripheral vascular K+ATP-channel agonism. This may compound the vasodilatory effects of verapamil and offset any hemodynamic improvements produced by increased cardiac output.