Procalcitonin for the early discrimination of fever etiology in patients with systemic autoimmune diseases attending the emergency department

GRADE-based procalcitonin guideline for emergency departments

Procalcitonin is a useful biomarker for infection. Over the past two decades, there has been much research on the clinical applications of procalcitonin, yet the majority of these studies have been conducted in the intensive care setting. Despite the extensive use of procalcitonin in emergency departments, there have been no guidelines focusing specifically on these clinical settings. Additionally, previous guidelines were predominantly shaped by expert consensus and rarely incorporate evidence-based medicine concepts. To address these shortcomings, the current guideline adopts a novel approach. Initially, we identified the most critical questions regarding the use of procalcitonin in emergency settings through expert voting. This was followed by a systematic literature review and the evaluation of evidence levels using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) methodology. Key characteristics of individual studies will be summarized and evaluated by the guideline development group to determine the overall quality of evidence. The GRADE working group's categorization system will be employed to rate evidence quality into four levels. Recommendations will be formulated based on explicit consideration of established criteria. This structured approach ensures that guideline recommendations are founded on robust evidence and transparently assessed for strength and potential caveats. This is the first guideline on the use of procalcitonin to be applied in emergency departments that adopts the principles of evidence-based medicine and encompasses the up-to-date literatures, and it marks an advancement in providing guidance on the utilization of procalcitonin in emergency departments.

Diagnosis and management of autoimmune diseases in the ICU

Autoimmune diseases encompass a broad spectrum of disorders characterized by disturbed immunoregulation leading to the development of specific autoantibodies, resulting in inflammation and multiple organ involvement. A distinction should be made between connective tissue diseases (mainly systemic lupus erythematosus, systemic scleroderma, inflammatory muscle diseases, and rheumatoid arthritis) and vasculitides (mainly small-vessel vasculitis such as antineutrophil cytoplasmic antibody-associated vasculitis and immune-complex mediated vasculitis). Admission of patients with autoimmune diseases to the intensive care unit (ICU) is often triggered by disease flare-ups, infections, and organ failure and is associated with high mortality rates. Management of these patients is complex, including prompt disease identification, immunosuppressive treatment initiation, and life-sustaining therapies, and requires multi-disciplinary involvement. Data about autoimmune diseases in the ICU are limited and there is a need for multicenter, international collaboration to improve patients' diagnosis, management, and outcomes. The objective of this narrative review is to summarize the epidemiology, clinical features, and selected management of severe systemic autoimmune diseases.