Gastrointestinal Pathology, Pathology, USMLE Step 1 - Full Vignette with Extended Explanations скачать в хорошем качестве

Gastrointestinal Pathology, Pathology, USMLE Step 1 - Full Vignette with Extended Explanations

A 49-year-old woman with extensive autoimmune and gastrointestinal history presents to the ICU with severe abdominal pain, bloody diarrhea, and pronounced abdominal distension. Laboratory and imaging reveal significant colonic dilation. With her complex background-including multiple drug allergies-and rapidly worsening clinical status, what key clinical features and diagnostic clues should guide immediate risk assessment and decision-making in this high-stakes scenario? VIDEO INFO Category: Gastrointestinal Pathology, Pathology, USMLE Step 1 Difficulty: Moderate - Intermediate level - Requires solid foundational knowledge Question Type: Contraindications Case Type: Critical Condition Explore more ways to learn on this and other topics by going to https://endlessmedical.academy/auth?h... QUESTION A 49-year-old woman is brought to the intensive care unit with severe abdominal pain, grossly bloody diarrhea, and marked abdominal distension after a week of worsening symptoms. On arrival, pulse is 117, blood pressure 136/88 (repeat readings confirm improvement from an outside automated value of 302/220), respirations 22 with shallow effort, oxygen saturation 92% on 3 L nasal cannula, and temperature 37.8 degreesC.... OPTIONS A. Full colonoscopy with bowel preparation to assess disease extent in acute severe ulcerative colitis with radiographic megacolon; perform limited, minimal-insufflation flexible sigmoidoscopy instead. B. Intravenous methylprednisolone at guideline dosing to induce remission in acute severe ulcerative colitis while monitoring for infection and perforation. C. Empiric broad-spectrum intravenous antibiotics targeting gram-negatives and anaerobes when toxic megacolon or sepsis is suspected in acute colitis. D. Pharmacologic venous thromboembolism prophylaxis with low-molecular-weight heparin throughout hospitalization for acute severe colitis, with individualized bleeding risk assessment and temporary holds only for active hemorrhage. CORRECT ANSWER A. Full colonoscopy with bowel preparation to assess disease extent in acute severe ulcerative colitis with radiographic megacolon; perform limited, minimal-insufflation flexible sigmoidoscopy instead. EXPLANATION Toxic megacolon is a life-threatening complication of severe colitis characterized by systemic toxicity and marked colonic dilation. Full colonoscopy with bowel preparation is contraindicated due to perforation risk from mechanical and barotrauma stresses and cathartic-induced motility. Instead, limited flexible sigmoidoscopy with minimal insufflation is used to confirm severity and obtain biopsies. This patient has tachycardia, leukocytosis, elevated inflammatory markers, and imaging-confirmed megacolon, fulfilling criteria for acute severe colitis with megacolon. The other interventions are appropriate in this context. Intravenous methylprednisolone at guideline dosing is recommended as first-line medical therapy for acute severe ulcerative colitis while evaluating for infection. Empiric broad-spectrum intravenous antibiotics are reasonable when toxic megacolon or sepsis is suspected.... 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. ---------------------------------------------------