Laura Barcán

High active local levels of vancomycin without nephrotoxicity released from impacted bone allografts in 20 revision hip arthroplasties

Background Cancellous bone can act as a delivery vehicle for vancomycin without impairment of graft incorporation. However, local and systemic antibiotic levels, biological activity of vancomycin, interaction with antibiotic-loaded cement, and also nephrotoxicity of these composites have not yet been studied clinically. Material and methods Blood, drainage and urine samples of 20 consecutive patients undergoing revision total hip arthroplasties with impaction grafting technique utilizing 1 g of vancomycin per femoral head were studied. Plain PMMA cement was used in 10 cases, while PMMA with gentamycin was used in 5 cases and tobramycin was used in the remaining 5 cases. Biological activity of vancomycin was studied using kinetic killing curves in three ATCC organisms (methicillin-sensitive Staphylococcus aureus,methicillin-resistant Staphylo-coccus aureusand Pseudomonas aeruginosas).Quantification was done with fluorescent polarized immunoassay. Renal function was evaluated with preoperative and postoperative urea and creatinine. Results Local active bactericidal levels of vancomycin reached 1 400 μg/mL (average 5-point level = 367 μg/mL) without nephrotoxicity. Vancomycin was present in urine until the fifteenth day. Both aminoglycosides in the cement had activity against Pseudomonas aeruginosas. Interpretation Local levels of vancomycin were 35 times greater than the highest levels reported with vancomycin-loaded PMMA. A synergistic effect was observed between vancomycin released from impacted allografts and aminoglycoside-loaded PMMA.

Transmission of T. cruzi infection via liver transplantation to a nonreactive recipient for Chagas' disease

Chagas disease is an endemic zoonosis of South America caused by a protozoan parasite Trypanosoma cruzi. About 30% of infected people develop the disease. This disease is known to reactivate in immunocompromised hosts, such as patients with acquired immunodeficiency syndrome, leukemia, and transplantation. There is some experience with transplantation of infected renal grafts into negative recipients, resulting in an index of transmission of 35%. No cases have been reported involving other organ transplants up to 2002, when the Centers for Disease Control and Prevention reported 3 cases of Chagas disease transmission to 3 recipients (liver, kidney, and pancreas‐kidney) from a single chagas infected donor. Here we report on a case of orthotopic liver transplant from a chagas infected donor into a negative recipient in clinical emergency status. The recipient was monitored by direct parasitological Strout method and serological tests with detection of transmission on the 84th day by both studies, without clinical signs. The patient was put on benznidazole with rapid clearance of the parasitemia. However, we propose that chagas infected donors may be accepted for liver transplant recipients only in emergency status. (Liver Transpl 2005;11:1112–1116.)

Organ Transplantation and Chagas Disease

1. Stephan BC, Matthews FE, McKeith IG, Bond J, Brayne C; Medical Research Council Cognitive Function and Aging Study. Early cognitive change in the general population. J Am Geriatr Soc. 2007;55(10):1534-1540. 2. Boustani M, Callahan C, Unverzagt F, et al. Implementing dementia screening and diagnosis in primary care. J Gen Intern Med. 2005;20(7):572-577. 3. UK National Screening Committee. http://www.nsc.nhs.uk. Accessed January 7, 2008. 4. Boustani M, Fox C, Katona C, et al. Patients’ perceptions about dementia screening in the United Kingdom and the United States. Alzheimers Dement. 2006; 2(3)(suppl 1):S587. 5. Borson S, Scanlan JM, Hummel J, Gibbs K, Lessig M, Zuhr E. Implementing routine cognitive screening of older adults in primary care. J Gen Intern Med. 2007; 22(6):811-817. 6. Brodaty H, Low LF, Gibson L, Burns K. What is the best dementia screening instrument for general practitioners to use? Am J Geriatr Psychiatry. 2006;14 (5):391-400.

Pandemic influenza A/H1N1 virus infection in solid organ transplant recipients: a multicenter study.

Background. The 2009 novel influenza A/H1N1 virus pandemic did not spare solid organ transplant (SOT) recipients. We aimed to describe the behavior of pandemic influenza infection in a group of SOT recipients in Argentina. Methods. Data from 10 transplant (Tx) centers were retrospectively collected for SOT that presented with a respiratory illness compatible with pandemic influenza A infection, between May and September 2009. Cases were defined as suspected, probable, or confirmed according to diagnostic method. Results. Seventy-seven cases were included. No significant differences in presenting symptoms, pulmonary infiltrates, and graft involvement were found among 35 suspected, 19 probable, and 23 confirmed cases. The 33 ambulatory cases had significantly more sore throat and headache when compared with 34 cases admitted to medical ward (MW) and 10 admitted to intensive care unit (ICU), 9 of whom required ventilatory support. MW and ICU cases had significantly more dyspnea, hypoxemia, pulmonary infiltrates, and graft dysfunction. Time from onset of symptoms to first visit and to treatment was significantly longer in MW and ICU cases (P=0.008). Coinfections were found in six cases. Most cases received oseltamivir for 5 to 10 days. Six patients (7.8%) died from viral infection at a median of 15 days from admission. No differences in outcome were seen related to the transplanted organ, the immunosuppressive regimen, time from Tx, or confirmation of diagnosis. Conclusions. Mortality is higher in Tx recipients than in the general population. Poor outcome seems to be related to a delay in the beginning of treatment.

Effect of the embolization of completely unpurified islets on portal vein pressure and hepatic biochemistry in clinical practice.

Here we report on the impact of completely unpurified islet transplantation on the portal vein pressure (PVP) and the hepatic biochemistry in the peritransplant period and on follow-up. Type I diabetic patients underwent simultaneous kidney and islet transplantation. Islets were not purified from the acinar tissue to prevent loss of endocrine mass. Each patient received a mean 521,846 ± 201,539.4 islet equivalents (7812.1 islet equivalents/kg/recipient). Immunosuppression and peritransplant medication were given according to the Giessen protocol. The islets were injected into the left hepatic lobe through the umbilical vein. PVP was recorded at time 0 and every 5 min throughout cell infusion. Liver function was assessed daily for the first 10 days, and on follow-up. Basal, peak, and final PVP were 12 ± 3.8, 25.1 ± 7.9, and 19.5 ± 6.2 mmHg, respectively (basal vs. final, p < 0.05). Bilirubin, alkaline phosphatase, prothrombin time, and APTT stayed within normal range. Peak aspartate aminotransferase (AST), alanine aminotransferase (ALT), and serum amylase were 109.4 ± 61.2 IU/L (basal vs. peak, not significant), 79.5 ± 56.9 IU/L (basal vs. peak, not significant), and 887.5 ± 153.6 IU/L (basal vs. peak, p = 0.02), respectively. In all cases AST, ALT, and amylase normalized within 6 days posttransplant and remained so on follow-up (longest control, 33 months posttransplant). Although the intrahepatic infusion of unpurified pancreatic islets affects both the portal vein pressure and the hepatic biochemical profile, this effect is transient and does not compromise the safety of the procedure.

Early molecular diagnosis of acute Chagas disease after transplantation with organs from Trypanosoma cruzi-infected donors

Organ transplantation (TX) is a novel transmission modality of Chagas disease. The results of molecular diagnosis and characterization of Trypanosoma cruzi acute infection in naïve TX recipients transplanted with organs from infected deceased donors are reported. Peripheral blood and cerebrospinal fluid samples from the TX recipients of organs from infected donors were prospectively and sequentially studied for detection of T. cruzi by means of kinetoplastid DNA polymerase chain reaction (kDNA‐PCR). In positive blood samples, a PCR algorithm for identification of T. cruzi Discrete Typing Units (DTUs) and quantitative real‐time PCR (qPCR) to quantify parasitic loads were performed. Minicircle signatures of T. cruzi infecting populations were also analyzed using restriction fragment length polymorphism (RFLP)‐PCR. Eight seronegative TX recipients from four infected donors were studied. In five, the infection was detected at 68.4 days post‐TX (36–98 days). In one case, it was transmitted to two of three TX recipients. The comparison of the minicircle signatures revealed nearly identical RFLP‐PCR profiles, confirming a common source of infection. The five cases were infected by DTU TcV. This report reveals the relevance of systematic monitoring of TX recipients using PCR strategies in order to provide an early diagnosis allowing timely anti‐trypanosomal treatment.

Agreement analysis of variables involved in lipodystrophy syndrome definition in HIV-infected patients.

Background: Lipodystrophy studies in HIV‐infected patients have usually defined abnormalities in body fat by clinical evaluation and patient questionnaires. Despite the risk for bias with these subjective approaches, agreement analysis among the large number of variables employed was seldom performed. Objective: To analyze consistency between the usual approaches for definition of abnormalities in body fat distribution. Design: We evaluated agreement between the clinical and questionnaire findings for abnormalities in body fat in an HIV patient population under antiretroviral treatment followed in our institution, using different criteria for definitions of body fat abnormalities within the same data set. Methods: Kappa analysis for consistency and receiver‐operator characteristic (ROC) curve analysis were performed. Results: Low levels of agreement between clinical and patient perspectives were observed. Only one combination of criteria showed adequate agreement results. The waist/hip ratio showed low levels of agreement with all other variables, and no clear discriminative point was observed by ROC curve analysis. The ratio between the trunk fat content and the leg fat content assessed by dual energy x‐ray absorptiometry (DEXA) scan demonstrated better agreement and more clear discriminative values for both male and female patients. Conclusion: Agreement analyses may help in the selection of the subjective variable methodology and in the inclusion of consistent and nonredundant objective measurements for diagnosis of abnormalities in body fat.

Mediastinitis post-quirúrgica: Estudio caso - control

POST-SURGICAL MEDIASTINITIS. CASE CONTROL STUDYWe report the results of a case-control study of post-surgical mediastinitis,that we conducted for eighteen months. The aim of the study was to detect possiblerisk factors for mediastinal infection after cardiovascular surgery as well as toanalyze related clinical features. Thirty episodes of mediastinal infections over687 consecutive cardiovascular surgeries (4,4%) were registered during a controlperiod of 18 month at Hospital Italiano of Buenos Aires, Argentina. Among allvariables analyzed only the following were significantly associated to mediastinalinfection in the postoperative period: time elapsed at the recovery unit(p < 0.01) total time with catheter placed in the pulmonary artery (p: 0.05)and the rate of postoperative complications (p < 0.01). Six patients withmediastinal infection (20%) had undergone reoperation shortly after mainsurgery compared to only 3 (5%) in the control group (p: 0.05). The associationwith surgical events may be related to post-surgical causation. The presenceof fever, only after 72 hours from surgery, allowed discrimination betweenpatients with and without mediastinal infection. All case patients showedabnormalities in surgical wound, and 28 of these patients (93%) had at leasttwo local signs of infection. Among the 37 types of microorganisms isolatedfrom sternal secretion, 22 (59%) were gram-positive cocci, with

Spontaneous bacteremia and spontaneous bacterial peritonitis share similar prognosis in patients with cirrhosis: a cohort study

Background and aimsSpontaneous bacteremia is a poorly characterized infection in patients with cirrhosis. We compared the incidence of mortality and acute kidney injury in patients with spontaneous bacterial peritonitis and spontaneous bacteremia, and identified risk factors for mortality and acute kidney injury in patients with spontaneous bacteremia.MethodsWe performed a retrospective cohort study of patients with cirrhosis and spontaneous bacteremia or spontaneous bacterial peritonitis from 2008 to 2016 at Hospital Italiano, Buenos Aires. We compared the cumulative incidence of acute kidney injury and death between the two infections, and identified risk factors for these outcomes in patients with spontaneous bacteremia.ResultsSeventy-one patients with spontaneous bacteremia and 55 patients with spontaneous bacterial peritonitis were included. Most infections were nosocomial. Overall, 26% of bacteria were resistant and 11% multi-resistant. We found no significant association between acute kidney injury [subhazard ratio (sHR) 1.05 (95% confidence interval, CI 0.67–1.63, pxa0=xa00.83)] or death [sHR 1.15 (95% CI 0.60–2.20, pxa0=xa00.68)] and type of spontaneous infection in multivariate analyses adjusting for basal Model for End-Stage Liver Disease (MELD) score. In patients with spontaneous bacteremia, baseline MELD score was independently associated with acute kidney injury [sHR 1.07 (95% CI 1.03–1.11, pxa0=xa00.001)] and death [sHR 1.07 (95% CI 1.02–1.15, pxa0=xa00.03)].ConclusionsShort-term acute kidney injury and mortality rates were similar in patients with spontaneous bacteremia and spontaneous bacterial peritonitis. Risk assessment of patients with spontaneous bacteremia can be performed with baseline MELD score.

Protocol for extended antibiotic therapy after laparoscopic cholecystectomy for acute calculous cholecystitis (Cholecystectomy Antibiotic Randomised Trial, CHART)

Introduction Acute calculous cholecystitis represents one of the most common complications of cholelithiasis. While laparoscopic cholecystectomy is the standard treatment in mild and moderate forms, the need for antibiotic therapy after surgery remains undefined. The aim of the randomised controlled Cholecystectomy Antibiotic Randomised Trial (CHART) is therefore to assess if there are benefits in the use of postoperative antibiotics in patients with mild or moderate acute cholecystitis in whom a laparoscopic cholecystectomy is performed. Methods and analysis A single-centre, double-blind, randomised trial. After screening for eligibility and informed consent, 300 patients admitted for acute calculus cholecystitis will be randomised into two groups of treatment, either receiving amoxicillin/clavulanic acid or placebo for 5 consecutive days. Postoperative evaluation will take place during the first 30u2005days. Postoperative infectious complications are the primary end point. Secondary end points are length of hospital stay, readmissions, need of reintervention (percutaneous or surgical reinterventions) and overall mortality. The results of this trial will provide strong evidence to either support or abandon the use of antibiotics after surgery, impacting directly in the incidence of adverse events associated with the use of antibiotics, the emergence of bacterial resistance and treatment costs. Ethics and dissemination This study and informed consent sheets have been approved by the Research Projects Evaluating Committee (CEPI) of Hospital Italiano de Buenos Aires (protocol N° 2111). Results The results of the trial will be reported in a peer-reviewed publication. Trial registration number NCT02057679.