Emergency Medicine EOR: Gastrointestinal and Nutritional (Smarty PANCE)

What is the most common surgical emergency presenting with abdominal pain?

Acute appendicitis - most common cause of emergency abdominal surgery in the US

What are the classic signs of peritonitis on abdominal exam?

Rebound tenderness, involuntary guarding, rigidity ("board-like abdomen"), positive Carnett's sign; indicates surgical emergency

What is the first-line imaging for undifferentiated acute abdominal pain in the ED?

CT abdomen/pelvis with IV contrast - highest sensitivity/specificity for most causes; ultrasound preferred in children and pregnant women

What are the three most common causes of acute abdominal pain requiring surgery (the "surgical triad")?

Appendicitis, cholecystitis, bowel obstruction - account for majority of emergent laparotomies

What pain pattern suggests mesenteric ischemia and what is the key clinical pearl?

Severe pain "out of proportion to exam" in a patient with atrial fibrillation or atherosclerosis - hallmark of acute mesenteric ischemia; lactate will be elevated late

What is the classic presentation of acute appendicitis?

Periumbilical pain migrating to RLQ (McBurney's point), anorexia, low-grade fever, nausea/vomiting; WBC elevated with left shift

What are the key physical exam signs in appendicitis?

McBurney's sign (RLQ tenderness 1/3 from ASIS to umbilicus), Rovsing's sign (RLQ pain with LLQ palpation), Psoas sign, Obturator sign

What is the gold standard diagnostic test for appendicitis in adults?

CT abdomen/pelvis with contrast - sensitivity 94-98%, specificity 95%; appendix >6mm, periappendiceal fat stranding, appendicolith

What score is used to risk-stratify appendicitis and what is the cutoff?

Alvarado score (MANTRELS): ≥7 = high probability for appendicitis; ≥5 in children warrants imaging; max score 10

What is the treatment for uncomplicated vs. complicated appendicitis?

Uncomplicated: laparoscopic appendectomy (antibiotics alone emerging option); Complicated (perforation/abscess): IV antibiotics + percutaneous drainage, interval appendectomy 6-8 weeks later

What is the classic triad of acute cholecystitis?

RUQ pain, fever, nausea/vomiting - pain often radiates to right shoulder/scapula (referred via phrenic nerve); Murphy's sign positive

What is Murphy's sign and what does it indicate?

Inspiratory arrest during deep palpation of RUQ - sensitivity 65%, specificity 87% for acute cholecystitis

What is the gold standard imaging for acute cholecystitis?

Ultrasound: gallstones + sonographic Murphy's sign + gallbladder wall thickening (>4mm) + pericholecystic fluid; HIDA scan most sensitive if US equivocal

What are the diagnostic criteria for acute cholecystitis (Tokyo Guidelines)?

Local signs (Murphy's/RUQ mass/pain/tenderness) + systemic inflammation (fever, elevated WBC/CRP) + confirmatory imaging

What is the treatment for acute cholecystitis?

NPO, IV fluids, IV antibiotics (cefazolin or pip/tazo), analgesia; laparoscopic cholecystectomy within 72 hours (early preferred over delayed)

What are the classic serologic markers for acute viral hepatitis?

ALT/AST markedly elevated (>1000 U/L, "hepatitic pattern"); check HAV IgM, HBsAg, HBcAb IgM, HCV Ab, EBV/CMV; AST:ALT ratio >2:1 suggests alcoholic hepatitis

How do you differentiate viral hepatitis types by serology?

HAV: anti-HAV IgM (acute); HBV: HBsAg + IgM anti-HBc (acute), HBeAg = high infectivity; HCV: anti-HCV Ab (may be negative early), confirm with HCV RNA

What AST:ALT ratio suggests alcoholic hepatitis and what is the ceiling of aminotransferases?

AST:ALT >2:1 (often 3:1) suggests alcoholic hepatitis; aminotransferases rarely exceed 300-500 U/L in alcoholic hepatitis (vs. >1000 in viral/ischemic)

What are indications for hospital admission in acute hepatitis?

INR >1.5, bilirubin >15, encephalopathy, hypoglycemia, inability to maintain hydration - signs of acute liver failure requiring urgent evaluation for transplant

What is Fitz-Hugh-Curtis syndrome?

Perihepatitis from N. gonorrhoeae or C. trachomatis - RUQ pain mimicking cholecystitis in young sexually active women; "violin string" adhesions on laparoscopy

What are the two most common causes of acute pancreatitis and their mnemonic?

Gallstones (40%) and Alcohol (35%) - "GET SMASHED": Gallstones, Ethanol, Trauma, Steroids, Mumps/Malignancy, Autoimmune, Scorpion/Spider, Hyperlipidemia/Hypercalcemia, ERCP/Drugs

What lipase level is diagnostic for acute pancreatitis?

Lipase ≥3x upper limit of normal (more sensitive and specific than amylase; lipase remains elevated longer 7-14 days vs. amylase 3-5 days)

What scoring system predicts severity/mortality in acute pancreatitis in the ED?

BISAP score: BUN >25, Impaired mental status, SIRS criteria (≥2), Age >60, Pleural effusion; score ≥3 = severe; Ranson's criteria used at 48 hours

What CT finding is diagnostic of necrotizing pancreatitis and when should CT be obtained?

CT abdomen with IV contrast: pancreatic necrosis = lack of enhancement; indicated if diagnosis uncertain, no improvement in 48-72h, or to evaluate complications

What is the treatment for acute pancreatitis?

Aggressive IV fluid resuscitation (LR preferred over NS), analgesia (IV opioids), NPO initially then early oral feeding as tolerated; antibiotics only for infected necrosis (not prophylactically)

What is the classic presentation of an anal fissure?

Severe tearing/burning pain during and after defecation, bright red blood on toilet paper; most common location = posterior midline (90%)

What is the first-line treatment for chronic anal fissure?

Topical nitroglycerin 0.2-0.4% or calcium channel blocker (diltiazem 2%) + sitz baths + fiber supplementation; Botox injection if medical therapy fails; lateral internal sphincterotomy = gold standard for chronic/refractory

What is the hallmark distinguishing feature of an anal fissure in an atypical location?

Lateral or multiple fissures should raise suspicion for Crohn's disease, HIV, syphilis, or TB - require further workup

What is an anal fistula and what is the classic presentation?

Abnormal tract between anal canal and perianal skin; presents with chronic perianal drainage, pain, recurrent abscesses; most arise from cryptoglandular infection

What is Goodsall's rule for anal fistulas?

Posterior external openings → curved tract to posterior midline; Anterior external openings → straight tract to nearest crypt; helps predict internal opening location

What is the treatment for a perianal abscess in the ED?

Incision and drainage (I&D) - antibiotics alone are insufficient; post-I&D, ~30-50% develop anal fistula; antibiotics adjunctive only for immunocompromised/cellulitis/systemic signs

What are the four types of perianal abscesses by location?

Perianal (most common, superficial), Ischiorectal, Intersphincteric, Supralevator (horseshoe abscess - most complex); deeper abscesses may require OR for drainage

What is the classic anorexia nervosa presentation and diagnostic criteria?

BMI < 18.5, intense fear of weight gain, distorted body image; labs: hypokalemia, hypomagnesemia, hypophosphatemia, elevated BUN (dehydration), prolonged QTc

What is the most dangerous complication of refeeding syndrome?

Severe hypophosphatemia → cardiac arrhythmias, respiratory failure, rhabdomyolysis; occurs when calories reintroduced too rapidly in severely malnourished patients

What is the Rome IV criteria for IBS (change in bowel habits)?

Recurrent abdominal pain ≥1 day/week for 3 months, associated with ≥2: related to defecation, change in stool frequency, change in stool form

What are the "red flag" symptoms requiring colonoscopy in a patient with change in bowel habits?

Age >45, rectal bleeding, nocturnal symptoms, unintentional weight loss, family history of colon cancer/IBD, iron deficiency anemia - rule out malignancy

What is the Bristol Stool Scale type associated with IBS-D vs. IBS-C?

IBS-D: Bristol type 6-7 (watery/loose); IBS-C: Bristol type 1-2 (hard/lumpy); alternating (IBS-M) includes both

What is the most important initial step in evaluating acute diarrhea in the ED?

Assess hydration status; acute diarrhea (< 2 weeks) usually infectious and self-limited; obtain stool culture, C. diff PCR if recent antibiotics, O&P if travel history

What are the criteria for C. difficile diagnosis and treatment?

Diagnosis: ≥3 unformed stools/day + positive C. diff PCR/toxin; Treatment: Non-severe = oral vancomycin 125mg QID x 10d (NOT metronidazole first-line per IDSA 2021); Severe/fulminant = oral vancomycin + IV metronidazole

What is Ogilvie syndrome (colonic pseudo-obstruction) and its treatment?

Massive colonic dilation without mechanical obstruction; treat with neostigmine IV (anticholinesterase) if no response to conservative therapy; colonoscopic decompression if neostigmine fails

What are the classic features of acute cholangitis (Charcot's triad and Reynolds' pentad)?

Charcot's triad: RUQ pain + fever/chills + jaundice; Reynolds' pentad adds: altered mental status + septic shock - indicates life-threatening suppurative cholangitis

What is the most common cause of cholangitis and its treatment?

Choledocholithiasis (gallstone in CBD) - treatment: urgent ERCP for biliary decompression + IV antibiotics (pip/tazo or cefepime + metronidazole); cholecystectomy electively

What labs confirm cholangitis vs. cholecystitis?

Cholangitis: elevated direct bilirubin + elevated alkaline phosphatase + dilated CBD on US (>6mm); cholecystitis: normal/mildly elevated bilirubin, CBD not dilated

What is the Child-Pugh score used for in cirrhosis?

Assesses severity and prognosis: measures Bilirubin, Albumin, INR/PT, Ascites, Encephalopathy (BAIAE); Child A=5-6 (well-compensated), B=7-9, C=10-15 (decompensated, poor prognosis)

What are the major complications of cirrhosis to recognize in the ED?

Ascites/SBP, hepatic encephalopathy, esophageal varices (bleeding), hepatorenal syndrome, hepatopulmonary syndrome, coagulopathy

What is spontaneous bacterial peritonitis (SBP) and how is it diagnosed?

Infection of ascitic fluid without surgical cause; diagnose by paracentesis: PMN count ≥250 cells/mm³; most common organism = E. coli; treat with cefotaxime 2g IV q8h + albumin

What is hepatic encephalopathy and its first-line treatment?

Portosystemic shunting of nitrogenous waste → altered consciousness; treat precipitating cause (GIB, infection, constipation, narcotics); lactulose (titrate to 2-3 soft BMs/day) + rifaximin for prophylaxis

What is diverticulitis and what is the classic presentation?

LLQ pain, fever, nausea, change in bowel habits; "left-sided appendicitis"; CT abdomen/pelvis with contrast is gold standard (pericolic fat stranding, bowel wall thickening, diverticulae)

What are the Hinchey classification stages and their management?

I: pericolic abscess (antibiotics ± percutaneous drainage); II: pelvic abscess (drainage + antibiotics); III: purulent peritonitis (surgery); IV: fecal peritonitis (emergent surgery)

When should antibiotics be prescribed for uncomplicated diverticulitis?

Current evidence (JAMA 2012, AVOD trial): uncomplicated diverticulitis can be managed WITHOUT antibiotics in immunocompetent patients; antibiotics for complicated or immunocompromised

What is the most common type of esophagitis and its classic presentation?

GERD-related esophagitis - heartburn worse with lying down/bending, regurgitation; EGD shows erythema/erosions; treat with PPI; eosinophilic esophagitis in younger atopic patients

What are the EGD findings that distinguish different types of esophagitis?

GERD: linear erosions at GEJ; Eosinophilic: rings/"trachealization," linear furrows, >15 eos/hpf on biopsy; Infectious (Candida): white plaques; CMV/HSV: ulcerations

What is Candida esophagitis and who gets it?

Immunocompromised patients (HIV, transplant, steroids, DM); dysphagia + odynophagia + thrush (but 1/3 have no thrush); treat with fluconazole 200mg x 14-21 days

What is the most common cause of gastritis and its treatment?

H. pylori (70%); confirm with urea breath test or stool antigen (off PPI 2 weeks); treat with bismuth quadruple therapy × 14 days (clarithromycin triple therapy only if susceptible)

What are the risk factors for stress gastritis (stress-related mucosal disease) in ICU patients?

Mechanical ventilation >48h, coagulopathy (INR >1.5, plt

What electrolyte abnormalities are seen with severe vomiting from gastric outlet obstruction?

Hypochloremic, hypokalemic metabolic alkalosis ("contraction alkalosis") - loss of HCl and K+ from vomiting; paradoxical aciduria (kidneys retain H+ to preserve Na+)

What are the most common viral causes of gastroenteritis and their classic features?

Norovirus: sudden onset, projectile vomiting, 24-48h duration, highly contagious; Rotavirus: children

What bacteria cause inflammatory (bloody) diarrhea vs. watery diarrhea?

Bloody/inflammatory: Shigella, EHEC (O157:H7), Salmonella, Campylobacter, C. diff; Watery/secretory: Vibrio cholerae, ETEC, Staph aureus, B. cereus, viral

When should antibiotics be given for bacterial gastroenteritis?

Shigella (always), Vibrio cholerae (always), Traveler's diarrhea (azithromycin), C. diff (always); avoid antibiotics in EHEC O157:H7 (increases HUS risk); Salmonella only if bacteremic/immunocompromised

What is the most common cause of upper GI bleeding (UGIB) vs. lower GI bleeding (LGIB)?

UGIB: peptic ulcer disease (PUD) #1; LGIB: diverticulosis #1 (adults), hemorrhoids (most common cause of BRBPR overall)

What is the Glasgow-Blatchford Score and when is it used?

Risk stratifies UGIB for need for endoscopic intervention; score 0 = low risk, safe for outpatient management; inputs: BUN, hemoglobin, SBP, HR, melena, syncope, hepatic/cardiac disease

What is the initial resuscitation for massive GI bleeding?

2 large-bore IVs, type and crossmatch, IV PPI (pantoprazole 80mg bolus then 8mg/hr for UGIB), octreotide if variceal suspected (50mcg bolus + 50mcg/hr); target Hgb >7; EGD within 24h (12h if variceal)

What are the indications for emergent surgery in GIB?

Hemodynamic instability despite resuscitation, transfusion requirement >6 units pRBC/24h, failure of endoscopic hemostasis, free perforation

What is Giardia lamblia and how is it transmitted and treated?

Flagellated protozoan; fecal-oral via contaminated water (campers/"beaver fever"); presents with bloating, foul-smelling fatty diarrhea (steatorrhea), NO bloody diarrhea; treat with metronidazole 250mg TID x 5-7d or tinidazole single dose

How is Giardia diagnosed?

Stool O&P (multiple specimens needed, sensitivity ~60-90% for 3 specimens); stool ELISA antigen testing preferred (sensitivity >90%); string test (Enterotest) rarely used

What are the key features of Entamoeba histolytica infection?

Travel to endemic area; flask-shaped ulcers in colon; bloody mucoid diarrhea; can cause amebic liver abscess (RUQ pain, fever, "anchovy paste" drainage); treat with metronidazole + paromomycin (luminal agent)

What is the most common helminth infection in the US and its treatment?

Enterobius vermicularis (pinworm) - perianal pruritus worse at night; diagnose with tape test; treat with albendazole 400mg single dose OR mebendazole (repeat in 2 weeks); treat entire household

What parasite causes biliary/intestinal obstruction and is the most common helminth worldwide?

Ascaris lumbricoides - giant roundworm; may cause SBO, biliary obstruction, or pulmonary Löffler syndrome; treat with albendazole or mebendazole

What is the classic presentation of GERD and what differentiates it from cardiac chest pain?

Substernal burning worse postprandially, lying flat, bending over; relieved by antacids; no radiation to arm/jaw, no diaphoresis; persistent symptoms require EGD to rule out Barrett's esophagus

What is Barrett's esophagus and who is at risk?

Metaplasia of squamous → columnar (intestinal) epithelium at GEJ from chronic GERD; risk of esophageal adenocarcinoma 30-40x; diagnose by EGD + biopsy; manage with high-dose PPI + surveillance EGD every 3-5y

What are alarm symptoms with heartburn requiring urgent EGD?

Dysphagia, odynophagia, weight loss, anemia, hematemesis, age >45 with new symptoms, prior esophageal disease - rule out malignancy or severe esophagitis

What is the most common cause of hematemesis and how is it differentiated from hemoptysis?

PUD most common; differentiate: hematemesis = acidic pH, food particles, brown/red, preceded by nausea; hemoptysis = alkaline, frothy/bright red, preceded by cough

What is the initial management of hematemesis in the ED?

ABCs first - protect airway (intubate if unable to protect); 2 large-bore IVs; IV PPI bolus; type and cross; consider octreotide if variceal suspected; emergent GI consult for EGD

What is the Forrest classification of peptic ulcers on EGD?

Ia: spurting vessel (90% rebleed - treat); Ib: oozing (10-30%); IIa: visible vessel (50%); IIb: adherent clot (25-30%); IIc: flat pigmented spot (7-10%); III: clean base (

What is the most common cause of thrombosed external hemorrhoid and its treatment?

Sudden onset severe perianal pain with a firm, tender, blue-purple lump; caused by straining/constipation; treat with excision (not just incision) within 72 hours for best results; after 72h, conservative (sitz baths, fiber, analgesia)

How do internal vs. external hemorrhoids differ in presentation?

Internal: painless bright red rectal bleeding (above dentate line, no somatic innervation); External: painful, below dentate line; thrombosed external = extremely painful

What are the 4 grades of internal hemorrhoids?

Grade I: bleeding, no prolapse; Grade II: prolapse with spontaneous reduction; Grade III: prolapse requiring manual reduction; Grade IV: irreducible prolapse - consider surgical referral

What is the key clinical distinction between incarcerated and strangulated hernia?

Incarcerated: hernia that cannot be manually reduced (bowel/omentum trapped but still viable); Strangulated: compromised blood supply → bowel ischemia/necrosis; strangulated = surgical emergency

What are the signs of strangulated hernia?

Sudden onset severe pain, fever, leukocytosis, nausea/vomiting, signs of peritonitis/bowel obstruction; CT confirms - surgical emergency, do NOT attempt manual reduction

What is the technique for hernia reduction (taxis)?

Trendelenburg position (15-20°), sedation/analgesia, gentle sustained pressure; successful in ~70% of incarcerated hernias; contraindicated if strangulation suspected or signs of peritonitis

What hernias are most at risk for strangulation?

Femoral hernias (highest risk, narrow neck), Richter's hernia (partial bowel wall herniation - can strangulate without bowel obstruction)

What is the most common hernia in men vs. women?

Men: indirect inguinal hernia; Women: indirect inguinal (still most common overall, but femoral hernia relatively more common than in men)

What is the most common cause of infectious diarrhea in the developed world?

Norovirus (viral); most common bacterial cause = Campylobacter jejuni (US) followed by non-typhoidal Salmonella

What bacteria classically cause food poisoning within hours of ingestion?

Staph aureus (preformed toxin): 1-6 hours, vomiting > diarrhea; B. cereus emetic type: 1-6 hours (fried rice); Clostridium perfringens: 8-12 hours; ETEC/Salmonella: 12-72 hours

What is traveler's diarrhea, its etiology, and treatment?

ETEC most common cause; ≥3 loose stools/24h + one symptom (fever, cramps, vomiting) in traveler; treat with azithromycin 1g single dose (preferred, especially Asia) or cipro x 1-3 days

What is the difference between Crohn's disease and ulcerative colitis in clinical presentation?

Crohn's: skip lesions, transmural, any GI tract (mouth to anus), perianal disease, fistulas, cobblestone mucosa, NO curative surgery; UC: continuous, mucosal only, rectum to colon, bloody diarrhea, CURATIVE colectomy

What is the gold standard diagnosis for IBD?

Colonoscopy with biopsy; Crohn's: granulomas (non-caseating), transmural inflammation; UC: crypt abscesses, goblet cell depletion, mucosal/submucosal only

What are the extraintestinal manifestations of IBD?

Joint: peripheral arthritis, ankylosing spondylitis; Skin: erythema nodosum, pyoderma gangrenosum; Eye: uveitis, episcleritis; Liver: primary sclerosing cholangitis (UC>Crohn); Kidney: oxalate stones

What are the medical treatment options for IBD flare in the ED?

Mild-moderate UC: mesalamine; Moderate-severe: IV corticosteroids (methylprednisolone); Biologics (infliximab) for steroid-refractory; antibiotics (cipro/metronidazole) for septic complications

What are the criteria for toxic megacolon?

Radiographic colonic dilation >6cm (transverse colon) PLUS ≥3 of: fever >38.6°C, HR >120, WBC >10,500, anemia; PLUS ≥1 of: dehydration, altered mental status, electrolyte abnormalities, hypotension

What is the treatment for toxic megacolon in the ED?

NPO, NG decompression, IV fluids, IV corticosteroids, broad-spectrum antibiotics (ciprofloxacin + metronidazole or pip/tazo); avoid antidiarrheals/opioids/anticholinergics; urgent surgery (subtotal colectomy) if no improvement in 24-72h

What is the most common cause of toxic megacolon?

UC most common; also Crohn's colitis, C. difficile colitis, CMV colitis; precipitated by hypokalemia, antidiarrheals, opioids

What is the classic presentation of acute mesenteric ischemia?

Severe periumbilical pain "out of proportion to exam," elderly patient with Afib or atherosclerosis; elevated lactate is a LATE finding; gold standard = CT angiography or conventional angiography

What are the four types of mesenteric ischemia and their causes?

Arterial embolism (50%, Afib most common), Arterial thrombosis (25%, atherosclerosis), Non-occlusive (20%, low-flow states/vasopressors), Venous thrombosis (5%, hypercoagulable)

What is the treatment for acute mesenteric ischemia?

Immediate surgical/vascular surgery consult; anticoagulation (heparin); endovascular vs. open surgery based on type; bowel resection for necrosis; mortality >50% with delayed diagnosis

What is ischemic colitis and how does it differ from acute mesenteric ischemia?

Ischemic colitis: most common form of mesenteric ischemia, affects watershed areas (splenic flexure, rectosigmoid junction); lower acuity than AMI; presents with LLQ pain + bloody diarrhea; often self-limited

What are the main causes of jaundice categorized by type?

Pre-hepatic: hemolysis (indirect bili elevated); Hepatic: hepatitis/cirrhosis (both); Post-hepatic: obstruction/cholestasis (direct bili elevated, elevated ALP, dark urine, clay stools)

What lab pattern distinguishes obstructive jaundice from hepatocellular jaundice?

Obstructive: direct (conjugated) bilirubin elevated, ALP/GGT markedly elevated, AST/ALT mildly elevated; Hepatocellular: both direct/indirect elevated, AST/ALT markedly elevated

What is the first-line imaging for painless jaundice in the ED?

RUQ ultrasound - evaluates for biliary dilation (CBD >6mm suggests obstruction), gallstones, liver lesions; MRCP/ERCP if biliary obstruction confirmed

What is Mallory-Weiss tear and its classic presentation?

Longitudinal mucosal tear at GEJ from forceful vomiting/retching; classic: alcoholic with recurrent vomiting then hematemesis; usually stops spontaneously (90%); EGD confirmatory and therapeutic