Safety of a strategy combining D-dimer testing and whole-leg ultrasonography to rule out deep vein thrombosis

Guidelines for the diagnostic workup of deep vein thrombosis (DVT) recommend assessing the clinical pretest probability before proceeding to D-dimer testing and/or compression ultrasonography (CUS) if the patient has high pretest probability or positive D-dimer. Referring only patients with positive D-dimer for whole-leg CUS irrespective of pretest probability may simplify the workup of DVT. In this prospective management outcome study, we assessed the safety of such a strategy. We included consecutive outpatients referred to the Emergency Department at Østfold Hospital, Norway, with suspected DVT between February 2015 and November 2018. STA-Liatest D-Di Plus D-dimer was analyzed for all patients, and only patients with levels ≥0.5 µg/mL were referred for CUS. All patients with negative D-dimer or negative CUS were followed for 3 months to assess the venous thromboembolic rate. One thousand three hundred ninety-seven patients were included. Median age was 64 years (interquartile range, 52-73 years), and 770 patients (55%) were female. D-dimer was negative in 415 patients (29.7%) and positive in 982 patients (70.3%). DVT was diagnosed in 277 patients (19.8%). Six patients in whom DVT was ruled out at baseline were diagnosed with DVT within 3 months of follow-up for a thromboembolic rate of 0.5% (95% confidence interval, 0.2-1.2). A simple diagnostic approach with initial stand-alone D-dimer followed by a single whole-leg CUS in patients with positive D-dimer safely ruled out DVT. We consider this strategy to be a valuable alternative to the conventional workup of DVT in outpatients. This trial was registered at www.clinicaltrials.gov as #NCT02486445.

Avoiding Anchoring Bias in the Times of the Pandemic!

COVID-19 has a broad spectrum of clinical presentations, including central nervous system manifestations that are not uncommon. The high pretest probability of COVID-19 in pandemic can lead to anchoring. We present a patient of COVID-19 pneumonia who presented with dyspnea and acute confusional state. His initial workup was suggestive of tuberculous meningoencephalitis with lymphocytic pleocytosis, high protein in CSF analysis, and suspicious MRI findings, which was later confirmed with a positive CSF culture. To the best of our knowledge, it is the first such case. Anchoring to the diagnosis of COVID-19 may deter clinicians from considering other concurrent diagnoses and a poor outcome consequently.

Accuracy of a Novel Urine Test, Fujifilm SILVAMP Tuberculosis Lipoarabinomannan, for the Diagnosis of Pulmonary Tuberculosis in Children

Background An accurate point-of-care test for tuberculosis (TB) in children remains an elusive goal. Recent evaluation of a novel point-of-care urinary lipoarabinomannan test, Fujifilm SILVAMP Tuberculosis Lipoarabinomannan (FujiLAM), in adults living with human immunodeficiency virus (HIV) showed significantly superior sensitivity than the current Alere Determine Tuberculosis Lipoarabinomannan test (AlereLAM). We therefore compared the accuracy of FujiLAM and AlereLAM in children with suspected TB. Methods Children hospitalized with suspected TB in Cape Town, South Africa, were enrolled (consecutive admissions plus enrichment for a group of children living with HIV and with TB), their urine was collected and biobanked, and their sputum was tested with mycobacterial culture and Xpert MTB/RIF or Xpert MTB/RIF Ultra. Biobanked urine was subsequently batch tested with FujiLAM and AlereLAM. Children were categorized as having microbiologically confirmed TB, unconfirmed TB (clinically diagnosed), or unlikely TB. Results A total of 204 children were enrolled and had valid results from both index tests, as well as sputum microbiological testing. Compared to a microbiological reference standard, the sensitivity of FujiLAM and AlereLAM was similar (42% and 50%, respectively), but lower than that of Xpert MTB/RIF of sputum (74%). The sensitivity of FujiLAM was higher in children living with HIV (60%) and malnourished children (62%). The specificity of FujiLAM was substantially higher than that of AlereLAM (92% vs 66%, respectively). The specificity of both tests was higher in children 2 years or older (FujiLAM, 96%; AlereLAM, 72%). Conclusions The high specificity of FujiLAM suggests utility as a “rule-in” test for children with a high pretest probability of TB, including hospitalized children living with HIV or with malnutrition.

Neuropsychiatric Manifestations of Neurocysticercosis

A common scenario in the Emergency Department shows patients presenting with abnormal behavior and agitation. A full workup is performed to rule out organic causes for the patients’ presentation after which they are referred to the Psychiatry Department for further assessment regarding major mental disorders. Similarly, the aforementioned protocol was followed for our patient and he was admitted to the psychiatry ward but was later referred to the Neurology and Infectious Diseases Unit as he developed altered mental status. He was then diagnosed as having neurocysticercosis (NCC), which is a common parasitic infection of the central nervous system. In a multiethnic city like Dubai, NCC should always be considered as a differential diagnosis for abnormal behavior. Symptomatic NCC carries a mortality rate of more than 50%, making early detection and treatment very important. Hence, it is encouraged to screen patients with a high pretest probability using brain CT and MRI.

Does This Patient Need Blood Cultures? A Scoping Review of Indications for Blood Cultures in Adult Nonneutropenic Inpatients

Guidance regarding indications for initial or follow-up blood cultures is limited. We conducted a scoping review of articles published between January 2004 and June 2019 that reported the yield of blood cultures and/or their impact in the clinical management of fever and common infectious syndromes in nonneutropenic adult inpatients. A total of 2893 articles were screened; 50 were included. Based on the reported incidence of bacteremia, syndromes were categorized into low, moderate, and high pretest probability of bacteremia. Routine blood cultures are recommended in syndromes with a high likelihood of bacteremia (eg, endovascular infections) and those with moderate likelihood when cultures from the primary source of infection are unavailable or when prompt initiation of antibiotics is needed prior to obtaining primary source cultures. In syndromes where blood cultures are low-yield, blood cultures can be considered for patients at risk of adverse events if a bacteremia is missed (eg, patient with pacemaker and severe purulent cellulitis). If a patient has adequate source control and risk factors or concern for endovascular infection are not present, most streptococci or Enterobacterales bacteremias do not require routine follow-up blood cultures.

Selection of non-invasive load procedure in diagnosis of ischemic heart disease (review)

The diagnosis of stable ischemic heart disease begins with a careful clinical examination of the patient and non-invasive testing to identify the disease. Patients with very low and very high pretest probability should not undergo various non-invasive tests. Various non-invasive tests are available to assess the presence of coronary heart disease in patients with an intermediate probability of ischemic heart disease (15–65%). The combination of anatomical with functional non-invasive tests helps improve diagnostic capabili of the disease.