Chiefs’ Inquiry Corner – 4/18/22

April 18, 2022

Chief residents of the NYU Langone Internal Medicine Residency give quick-and-easy, evidence-based answers to interesting questions posed by house staff, both in their clinics and on the wards.

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 An atrioesophageal fistula is a very rare (incidence rate of 0.03%-0.08%, although this may be an underestimate due to underreporting or misdiagnosis) but often fatal complication of atrial fibrillation ablation procedures resulting from profound thermal injury to the esophagus (due to its close proximity to the posterior wall of the left atrium, and also a larger left atrium-esophageal contact area often seen in people with atrial fibrillation and left atrial dilatation compared to those without such conditions) and surrounding structures. As development of a fistula is not instantaneous, this complication is considered to be late/delayed, with median time from ablation procedure to clinical presentation of 21d (most common time range for presentation being 2-4 weeks post-procedure). The most common findings include fever (73%) and neurological symptoms (72%), which were defined as at least one of the following: seizure, confusion, loss of consciousness, and/or focal neurologic deficits. Less common symptoms include GI symptoms (41%) (including one or more of the following: hematemesis/melena, dysphagia/odynophagia, and/or nausea/vomiting) and chest pain (~35%). Urgent treatment is essential and can include surgery or endoscopic intervention; even so, overall mortality is estimated to be 55%.

References: Atrioesophageal Fistula: Clinical Presentation, Procedural Characteristics, Diagnostic Investigations, and Treatment Outcomes
 Uncomplicated MRSA bacteremia is defined as having a positive blood culture result plus meeting all of the following criteria: exclusion of endocarditis, no implanted prostheses, follow-up blood cultures performed 2-4 days after the initial positive cultures do not grow MRSA, defervescence within 72h of initiating effective therapy, and no evidence of metastatic sites of infection. Treatment entails either vancomycin or daptomycin for at least two weeks. Complicated MRSA bacteremia is defined as having a positive blood culture and failing to meet all of the criteria above for uncomplicated bacteremia. In these situations, length of therapy increases to 4-6 weeks, depending on the extent of infection.

References: Clinical Practice Guidelines by the Infectious Diseases Society of America for the Treatment of Methicillin-Resistant Staphylococcus aureus Infections in Adults and Children
 As many of us know, the first line treatment for management of knee osteoarthritis often starts with conservative therapies focusing on lifestyle interventions with an emphasis on exercise and education (ie physical therapy) often used in combination with tylenol, topical voltaren, or oral NSAIDs. However, exercise/education has never been studied in comparison with a placebo and are often only compared with “no treatment” control groups. A recent study was published in BMJ which compared an open-label randomized trial where 206 patients with symptomatic knee OA that was radiographically confirmed were randomized to an 8 week exercise/education program or 4 weekly injections of normal saline (placebo). The primary outcome was improvement in pain scores on KOOS (Knee Osteoarthritis Outcome Score) questionnaire. The end result was that there was no significant difference between those who completed the exercise and education program and those who received 4 inert NS injections to the knee. These findings suggest that exercise in knee OA may be no better than the placebo effect and perhaps the current recommendations of exercise/PT as a primary management strategy of knee OA should be reconsidered.

References: Exercise and education versus saline injections for knee osteoarthritis: a randomised controlled equivalence trial