USMLE 2 GI Quick Notes
| Mallory-Weiss | Boerhaave | |
| etiol. | mucosal tear 2/2 forceful retching; submucosal arterial or venule plexus bleeding | transmural tear 2/2 forceful retching; esophageal perforation with air/ fluid leakage |
| feat. | vomiting, retching epigastric pain hematemesis | vomiting, retching, retrosternal pain, WBC odynophagia, fever, dyspnea, or septic shock subcutaneous emphysema |
| Dx | EGD endoscopy | CT or contrast esophagography with Gastrografin CXR: pneumo- mediastinum & exudative pleural effusion (low pH, high amylase) |
| Rx | self-limited; endoscopic Rx as needed (clipping or coagulation) | cervical perforations: conservative measures thoracic perforations: surgery |
| ▪ Ulcerative colitis: MC in females, Ashkenazi Jew, peak @ age 15 – 25 ▪ MC site: rectum, confined to mucosal layer ▪ bloody diarrhea, tenesmus, pseudopolyps ▪ severe disease: weight loss, fever, or anemia ▪ +p-ANCA ▪ confirm Dx: friable mucosa on colonoscopy & biopsy with mucosal inflammation ▪ extraintestinal: erythema nodosum, uveitis, sclerosing cholangitis, spondyloarthropathy ▪ complications: toxic megacolon & colorectal ca ▪ surveillance: annual colonoscopies beginning at 8 – 10 yrs after Dx for colon cancer detection o colonic dysplasia is a/w progression to adenocarcinoma; Rx: total colectomy |
| ▪ chronic inflammatory diarrhea (< 4 wks): anemia, weight loss, ◇ ESR, acute phase reactants, reactive thrombocytosis, +occult blood/leukocyte stool |
| ▪ acute pancreatitis can cause unilateral, left-sided pleural effusion with high amylase concentration, but not widened mediastinum |
| ▪ spontaneous esophageal rupture after severe retching/vomiting: Boerhaave’s ▪ CXR: left-sided pleural effusion with/without pneumothorax, subcutaneous emphysema, & widened mediastinum ▪ exudative pleural fluid: low pH, high amylase (>2500 IU) ▪ Dx: CT or contrast esophagogram w/ Gastrografin (water-soluble contrast) |
| ➢ young patient, aphthous ulcer, chronic diarrhea, abdominal pain, weight loss: Crohn’s ▪ non-caseating granulomas, “cobblestone”, transmural inflammation, skip lesions, creeping fat, non-lymphoid aggregates ▪ MC site: terminal ileum; rectum is spared ▪ chronic GERD with new dysphagia & symmetric LES narrowing: esophageal stricture ▪ body’s reparative response to chronic acid exposure ▪ other causes: radiation, systemic sclerosis, caustic ▪ Dx: endoscopic biopsy to r/o adenocarcinoma ▪ DDx: adenocarcinoma (asymmetric narrowing), hiatal hernia, achalasia (aperistalsis) |
| ▪ age > 60, dysphagia, regurgitation, halitosis, cough, variable neck mass: Zenker diverticulum ▪ most important pathogenic factor in development of Zenker: motor dysfunction ▪ develops above the upper esophageal sphincter, with posterior herniation between cricopharyngeal muscle fibers ▪ risk for aspiration pneumonia ▪ Dx: barium esophagram ▪ Rx: excision, cricopharyngeal myotomy |
