Castillo Almeida, Natalia E

Abstract Purpose To identify risk factors that may predispose patients to rifampin- and cefazolin-induced coagulopathy. Summary An 86-year-old man with a history of rheumatoid arthritis on chronic prednisone and stage 3 chronic kidney disease, notably not on warfarin, presented to the hospital with a 10-day history of right hip pain, swelling, and drainage after a recent right total-hip arthroplasty. The patient underwent a combination of surgical intervention and medication therapy with rifampin and ceftriaxone. After discharge and at postoperative day 9, ceftriaxone was changed to cefazolin due to increasing alkaline phosphatase levels. Four weeks after the initial debridement, antibiotics, and implant retention, the patient underwent a second irrigation and debridement due to persistent infection. Cefazolin and rifampin therapy was extended. Three days later, the patient presented to the emergency room with significant bleeding at the surgical site and a profoundly elevated prothrombin time and international normalized ratio (INR). No potential contributors were identified. The Naranjo adverse drug reaction probability scale identified cefazolin and rifampin as the probable cause of elevated INR. The Liverpool adverse drug reaction avoidability assessment tool classified this adverse event as “definitely avoidable.” Conclusion Rifampin-containing regimens are often recommended to treat staphylococcal prosthetic joint infections when the implant is retained. In methicillin-susceptible staphylococcal infections, cefazolin is routinely employed as the β-lactam backbone of definitive antimicrobial regimens. Although rifampin- and cefazolin-induced hypoprothrombinemia seems to be rare, adverse consequences of its occurrence may be prevented with appropriate monitoring.

Abstract Background Nocardial brain abscesses are rare, and published literature describing brain abscesses due to Nocardia species is limited to individual case reports or small series. We report one of the largest contemporary retrospective studies describing risk factors, diagnostic evaluation, management, and outcomes of nocardial brain abscess. Methods Retrospective review of all adults with brain abscess due to culture-confirmed Nocardia species at our institution between January 1, 2009, and June 30, 2020. Results Overall, 24 patients had nocardial brain abscesses during the study period. The median age at presentation was 64 years, and 62.5% were immunocompromised. Pulmonary and cutaneous infections were the most common primary sites of nocardial infection. All 24 patients had magnetic resonance imaging performed, and the frontal lobe was the most commonly involved. The most common organism isolated was Nocardia farcinica, followed by Nocardia wallacei and Nocardia cyriacigeorgica. Thirteen patients were managed with antimicrobial therapy alone, while 11 had both medical and surgical management. In all patients, dual therapy was recommended for the initial 6 weeks of treatment, and 22 patients received at least 1 oral agent as part of their final antibiotic regimen, predominantly trimethoprim-sulfamethoxazole and linezolid. Fourteen patients achieved complete clinical and radiographic resolution of infection. Conclusions Nocardia is an important cause of brain abscess in the immunocompromised host. Early diagnostic and therapeutic aspiration may help health care providers confirm the diagnosis, choose an appropriate antimicrobial regimen, and achieve source control.

AbstractBackgroundAscertaining involvement of left ventricular assist device (LVAD) in a patient presenting with bloodstream infection (BSI) can be challenging, frequently leading to use of chronic antimicrobial suppressive (CAS) therapy. We aimed to assess the efficacy of CAS therapy to prevent relapse of BSI from LVAD and non-LVAD sources.MethodsWe retrospectively screened adults receiving LVAD support from 2010 through 2018, to identify cases of BSI. Bloodstream infection events were classified into LVAD-related, LVAD-associated, and non-LVAD BSIs.ResultsA total of 121 episodes of BSI were identified in 80 patients. Of these, 35 cases in the LVAD-related, 14 in the LVAD-associated, and 46 in the non-LVAD BSI groups completed the recommended initial course of therapy and were evaluated for CAS therapy. Chronic antimicrobial suppressive therapy was prescribed in most of the LVAD-related BSI cases (32 of 35, 91.4%) and 12 (37.5%) experienced relapse. Chronic antimicrobial suppressive therapy was not prescribed in a majority of non-LVAD BSI cases (33, 58.9%), and most (31, 93.9%) did not experience relapse. Chronic antimicrobial suppressive therapy was prescribed in 9 of 14 (64.2%) cases of LVAD-associated BSI and none experienced relapse. Of the 5 cases in this group that were managed without CAS, 2 had relapse.ConclusionsPatients presenting with LVAD-related BSI are at high risk of relapse. Consequently, CAS therapy may be a reasonable approach in the management of these cases. In contrast, routine use of CAS therapy may be unnecessary for non-LVAD BSIs.