Lower Limb Anatomy, Human Anatomy, USMLE Step 1 - Full Vignette with Extended Explanations скачать в хорошем качестве

Lower Limb Anatomy, Human Anatomy, USMLE Step 1 - Full Vignette with Extended Explanations

A 33-year-old pregnant woman develops acute left calf pain, swelling, and mild shortness of breath following prolonged travel. With physical examination revealing increased calf circumference and edema, how should one approach the diagnostic evaluation of lower limb symptoms in pregnancy? What key clinical features and anatomical considerations inform the optimal next step to assess for vascular complications in this setting? VIDEO INFO Category: Lower Limb Anatomy, Human Anatomy, USMLE Step 1 Difficulty: Easy - Basic level - Suitable for medical students Question Type: Diagnostic Step Case Type: Pregnant Patient Explore more ways to learn on this and other topics by going to https://endlessmedical.academy/auth?h... QUESTION A 33-year-old woman at 28 weeks of pregnancy presents with new left calf pain and swelling that began yesterday after a 6-hour car ride. She notes mild shortness of breath when climbing one flight of stairs but no chest pain. Past medical history includes microscopic polyangiitis in remission and severe combined immunodeficiency treated with bone marrow transplant in infancy; she has been well for years. Medications are prenatal vitamins and low-dose aspirin started early in pregnancy.... OPTIONS A. Order duplex compression ultrasonography of the symptomatic leg s proximal deep veins as the first test in pregnancy. B. Order a D-dimer blood test alone, using an age-adjusted threshold, to exclude deep vein thrombosis in this pregnant patient. C. Proceed directly to CT pulmonary angiography of the chest to look for thromboembolism before leg imaging. D. Perform contrast venography of the leg as the initial diagnostic study in the clinic today. CORRECT ANSWER A. Order duplex compression ultrasonography of the symptomatic leg s proximal deep veins as the first test in pregnancy. EXPLANATION Suspected DVT in pregnancy is evaluated first with compression duplex ultrasonography of the symptomatic leg s proximal deep veins. This noninvasive test directly assesses compressibility and flow in the femoral and popliteal veins, aligning with ACOG Practice Bulletin 196 (2018) and RCOG Green-top 37b (2015). The patient s unilateral calf swelling (3 cm difference), warmth, pitting edema, recent 6-hour car ride, and dyspnea on exertion increase pretest probability; she is hemodynamically stable, making leg ultrasound the best next step. A D-dimer alone should not be used to exclude DVT in pregnancy because D-dimer rises physiologically, and pregnancy-specific thresholds/algorithms are not universally validated; a negative test is unreliable for rule-out, and a positive test is nonspecific. Proceeding straight to CT pulmonary angiography exposes mother and fetus to radiation/contrast and targets PE rather than the symptomatic leg; in a stable patient without high suspicion of PE, leg ultrasound comes first.... Further reading: Links to sources are provided for optional further reading only. The questions and explanations are independently authored and do not reproduce or adapt any specific third-party text or content. --------------------------------------------------- Our cases and questions come from the https://EndlessMedical.Academy quiz engine - multi-model platform. Each question and explanation is forged by consensus between multiple top AI models (i.e. Open AI GPT, Claude, Grok, etc.), with automated web searches for the latest research and verified references. Calculations (e.g. eGFR, dosages) are checked via code execution to eliminate errors, and all references are reviewed by several AIs to minimize hallucinations. Important note: This material is entirely AI-generated and has not been verified by human experts; despite stringent consensus checks, perfect accuracy cannot be guaranteed. Exercise caution - always corroborate the content with trusted references or qualified professionals, and never apply information from this content to patient care or clinical decisions without independent verification. Clinicians already rely on AI and online tools - myself included - so treat this content as an additional focused aid, not a replacement for proper medical education. Visit https://endlessmedical.academy for more AI-supported resources and cases. This material can not be treated as medical advice. May contain errors. ---------------------------------------------------