Gastrointestinal

Appendicitis: diagnosis and management in adults

Clinical Overview and When to Suspect Appendicitis

— Lifetime risk ~7–8%; peak incidence age 10–30 but occurs at any age

— Most common surgical emergency of the abdomen in adults

— Slight male predominance; right-sided pain is classic but variable with anatomy

— 0–12 h: visceral periumbilical pain, anorexia, nausea

— 12–24 h: pain migrates to RLQ as parietal peritoneum is involved

— >24–48 h: risk of perforation rises sharply; elderly and immunosuppressed perforate faster and with fewer signs

— Any adult with new RLQ pain + anorexia + low-grade fever

— Periumbilical pain that "moves" and worsens with movement/coughing

— Atypical presentations: retrocecal appendix (flank/back pain, psoas sign), pelvic appendix (suprapubic pain, dysuria, diarrhea), pregnancy (RUQ in third trimester)

— Missed/delayed diagnosis is a leading malpractice claim in emergency abdominal pain

— Decisions hinge on appropriate imaging selection, antibiotic timing, and surgical vs. non-operative pathways

— CCS cases will reward early IV access, NPO status, analgesia, antibiotics, and surgical consult before imaging results return when suspicion is high

Board pearl: The single most sensitive symptom is anorexia—a hungry patient asking for a cheeseburger makes appendicitis much less likely. Conversely, pain that precedes vomiting favors a surgical abdomen, whereas vomiting before pain suggests gastroenteritis. Always frame appendicitis as a time-dependent diagnosis: perforation risk roughly doubles after 36 hours of symptoms.

Definition: Acute inflammation of the vermiform appendix, typically from luminal obstruction (fecalith, lymphoid hyperplasia, rarely tumor) → distension, ischemia, bacterial overgrowth, and ultimately perforation if untreated.

Epidemiology:

Pathophysiology timeline (helps anchor presentation):

When to actively suspect:

Why Step 3 cares about getting this right:

Presentation Patterns and Key History

— Periumbilical pain → migration to RLQ

— Anorexia, nausea, ± vomiting (usually after pain onset)

— Low-grade fever (38.0–38.5°C); high fever suggests perforation/abscess

— Onset: gradual over hours, not sudden (sudden = perforated ulcer, ruptured AAA, ovarian torsion)

— Quality: dull→sharp, worsened by movement, coughing, or car rides on bumpy roads ("pothole sign")

— Duration: typically <48 h on presentation; longer duration raises suspicion for perforation with walled-off abscess

— Retrocecal (most common variant): flank pain, fewer peritoneal signs, may mimic pyelonephritis

— Pelvic: suprapubic pain, urinary frequency, tenesmus, diarrhea—often mistaken for UTI or PID

— Subhepatic: RUQ pain mimicking cholecystitis

— Long appendix: LLQ pain possible (rare)

— Last menstrual period, contraception, sexual history (rule out ectopic, PID, ovarian pathology)

— Prior appendectomy (yes—stump appendicitis exists but is rare)

— Immunosuppression (HIV, chemo, steroids): blunts symptoms, raises perforation risk

— Recent travel, sick contacts (gastroenteritis), dietary changes

— Anticoagulation, bleeding disorders (affects surgical planning)

— Symptoms >48–72 h with palpable mass → likely phlegmon or abscess

— Diffuse abdominal pain, rigidity, hypotension → perforated with peritonitis

Step 3 management: In a reproductive-age woman with RLQ pain, always order a urine β-hCG before imaging or surgery—this single test changes the differential (ectopic pregnancy), imaging choice (US/MRI over CT), and consent discussion. Document the result before signing operative consent.

Classic triad/sequence (only ~50–60% of adults):

Pain characteristics to elicit:

Associated symptoms by appendix location:

Key history questions Step 3 expects:

Red flags suggesting complicated disease:

Physical Exam Findings and Hemodynamic Assessment

— Low-grade fever, mild tachycardia early

— High fever (>39°C), marked tachycardia, hypotension → suggests perforation, abscess, or sepsis; resuscitate before OR

— McBurney's point tenderness: 1/3 distance from ASIS to umbilicus on the right

— Rovsing's sign: RLQ pain elicited by palpating LLQ (referred parietal irritation)

— Psoas sign: pain with right hip extension (retrocecal appendix irritating psoas)

— Obturator sign: pain with internal rotation of flexed right hip (pelvic appendix)

— Dunphy's sign: RLQ pain with coughing

— Guarding/rebound: localized peritonitis; diffuse rebound = perforation

— Indicated in women of reproductive age to evaluate adnexal/cervical motion tenderness

— Rectal exam may reveal right-sided tenderness with pelvic appendix; not routinely required if imaging is planned

— Two large-bore IVs, isotonic crystalloid bolus (e.g., LR 500–1000 mL) if tachycardic or hypotensive

— Lactate, blood cultures if febrile/septic

— NPO, antiemetics, judicious opioid analgesia—analgesia does NOT mask the diagnosis (multiple RCTs); withholding pain meds is outdated practice

— Elderly: blunted exam, often present with perforation; lower threshold for imaging

— Pregnant: appendix displaced superolaterally; tenderness may be RUQ in third trimester

— Obese: exam unreliable; rely on imaging

CCS pearl: On a CCS case, after focused H&P, simultaneously order CBC, BMP, lactate, urinalysis, urine β-hCG, type and screen, IV fluids, IV antibiotics, and surgical consult—then move clock forward. Don't wait for labs to call surgery if your suspicion is high; documentation of timely consultation is scored.

Vital signs:

Abdominal exam—classic signs:

Pelvic and rectal exam:

Hemodynamic assessment & resuscitation priorities:

Special populations on exam:

Diagnostic Workup — Initial Labs and Imaging

— CBC: leukocytosis (10–18k) with left shift in ~80%; normal WBC does NOT rule out appendicitis

— CRP: elevated; combined WBC + CRP both normal has high negative predictive value

— BMP: baseline renal function before contrast CT

— Urinalysis: mild pyuria/hematuria possible (inflamed appendix near ureter); frank UTI suggests alternate diagnosis

— Urine β-hCG: mandatory in reproductive-age women

— LFTs, lipase: if biliary/pancreatic differential active

— Lactate, blood cultures: if septic

— Non-pregnant adults: CT abdomen/pelvis with IV contrast is gold standard (sensitivity ~95%, specificity ~95%); oral/rectal contrast not routinely required

— Pregnant women: start with graded-compression ultrasound; if non-diagnostic, MRI without gadolinium

— Children/young thin adults: ultrasound first to avoid radiation; CT if non-diagnostic

— Appendiceal diameter >6 mm, wall thickening >2 mm

— Periappendiceal fat stranding

— Appendicolith (fecalith)

— Free fluid, phlegmon, or abscess (complicated disease)

— Non-visualization of a normal appendix in the presence of secondary signs

— Non-compressible blind-ending tubular structure >6 mm

— Target sign on cross-section, hyperemia on Doppler

— Operator-dependent; non-visualization does not exclude

— Alvarado score and AIR score stratify risk and guide imaging vs. observation

— Score ≥7 highly suggestive; ≤3 unlikely

Key distinction: A normal WBC + normal CRP + low Alvarado score in a well-appearing patient has a negative predictive value >95%—observation with serial exams is acceptable rather than reflexive CT, particularly in younger patients where radiation matters.

Laboratory studies:

Imaging—first-line by population:

CT findings supporting appendicitis:

Ultrasound findings:

Scoring systems (adjuncts, not replacements):

Diagnostic Workup — Advanced and Confirmatory Studies

— Equivocal CT (e.g., appendix not visualized, borderline 6–7 mm without secondary signs): options include short-interval repeat imaging, MRI, or admission for serial abdominal exams every 2–4 hours

— Equivocal US in pregnancy → MRI without contrast (gadolinium avoided, especially in first trimester)

— Sensitivity ~95%, specificity ~95% in pregnancy

— No ionizing radiation; safe across all trimesters without gadolinium

— Findings mirror CT: enlarged appendix, periappendiceal edema, T2 hyperintensity

— Considered when imaging remains equivocal but clinical suspicion high, especially in women of reproductive age where gynecologic pathology overlaps

— Doubles as therapeutic if appendicitis confirmed

— Allows direct evaluation of ovaries, fallopian tubes, Meckel's diverticulum

— Uncomplicated: inflamed appendix without perforation, abscess, or phlegmon

— Complicated: perforation, gangrene, abscess (>3–4 cm), phlegmon, generalized peritonitis

— Imaging features of complicated disease: extraluminal air, abscess collection, large appendicolith, free fluid beyond pelvis

— In adults >40, look for underlying malignancy (carcinoid, mucinous neoplasm, adenocarcinoma)—appendix should be sent to pathology

— Appendicolith >1 cm on imaging predicts higher failure rate with antibiotics-only management

— Mucocele/mucinous neoplasm on imaging mandates surgical (not antibiotic) management to avoid pseudomyxoma peritonei from rupture

Board pearl: A palpable RLQ mass with several days of symptoms likely represents a phlegmon or contained abscess. Initial management is percutaneous drainage (if abscess >3–4 cm) + IV antibiotics + bowel rest, NOT immediate appendectomy—interval appendectomy 6–8 weeks later remains debated but common in those with appendicolith or >40 (to rule out malignancy via colonoscopy first).

When initial imaging is non-diagnostic:

MRI protocol considerations:

Diagnostic laparoscopy:

Identifying complicated vs. uncomplicated disease (drives management):

Special considerations:

Risk Stratification and First-Line Management Logic

— Uncomplicated appendicitis (no perforation, no abscess, no phlegmon)

— Complicated appendicitis (perforation, abscess, phlegmon, peritonitis)

— Uncomplicated, surgical candidate: laparoscopic appendectomy within 12–24 h is standard of care

— Uncomplicated, select patients: antibiotics-only ("NOTA"/CODA trial pathway) is an option in motivated patients without appendicolith—~30–40% recurrence at 5 years

— Complicated with localized abscess/phlegmon, stable: IV antibiotics + percutaneous drainage; consider interval appendectomy

— Complicated with generalized peritonitis or sepsis: urgent surgery after resuscitation

— NPO

— IV fluids (isotonic crystalloid)

— IV antibiotics within 1 hour of decision to operate

— Analgesia (acetaminophen, opioids as needed)

— Antiemetics

— Type and screen

— Informed consent including conversion to open, bowel injury, surgical site infection, recurrence with non-op management

— VTE prophylaxis (mechanical pre-op, pharmacologic post-op)

— Surgery within 24 h does not significantly increase complications vs. <8 h for uncomplicated cases—night surgery is no longer mandated

— Delays >24 h, however, increase perforation and SSI risk

— Uncomplicated CT findings, no appendicolith, no fecalith >1 cm

— No immunosuppression, no significant comorbidity precluding surgery if failure

— Shared decision-making documented; ~1 in 3 will need appendectomy within 5 years

Step 3 management: When counseling a patient on antibiotics vs. surgery for uncomplicated appendicitis, frame it as: surgery = definitive, one-time treatment with ~1–2% complication rate; antibiotics = avoid surgery short-term but 40% recurrence risk by 5 years and missed-malignancy concern in >40. Document the shared decision.

Step 1 — Confirm diagnosis and stratify:

Step 2 — Choose pathway:

Preoperative checklist (CCS-friendly):

Timing nuance:

Antibiotics-only management criteria:

Pharmacotherapy — First-Line Antibiotic Regimens

— Coverage: Gram-negatives (E. coli, Klebsiella) + anaerobes (Bacteroides fragilis) ± Enterococcus in complicated/healthcare-associated cases

— Start IV antibiotics before incision (within 60 minutes); single preoperative dose may suffice for uncomplicated cases

— Cefoxitin 2 g IV single dose, OR

— Cefazolin 2 g + metronidazole 500 mg IV, OR

— Ertapenem 1 g IV (broader, single dose)

— No postoperative antibiotics needed after uncomplicated appendectomy

— Ceftriaxone 2 g IV daily + metronidazole 500 mg IV q8h, OR

— Ertapenem 1 g IV daily (single agent, convenient)

— Piperacillin-tazobactam 3.375 g IV q6h (broader, includes Pseudomonas/Enterococcus)

— Duration: 4–7 days post-source control (STOP-IT trial: 4 days sufficient if source controlled)

— Piperacillin-tazobactam or meropenem 1 g IV q8h ± vancomycin if MRSA risk

— De-escalate based on cultures

— Ciprofloxacin + metronidazole (mild-moderate)

— Aztreonam + metronidazole (severe) ± vancomycin

— IV ertapenem or ceftriaxone/metronidazole for 24–48 h, then oral cefdinir + metronidazole (or amoxicillin-clavulanate) to complete 10 days total

— IV crystalloid resuscitation

— Analgesia: acetaminophen, ketorolac (avoid if AKI/bleeding), opioids as needed

— Antiemetics: ondansetron

Board pearl: Duration of post-source-control antibiotics in complicated intra-abdominal infection = 4 days (STOP-IT trial), provided source control is adequate. Longer courses do not reduce recurrence and increase C. difficile and resistance risk.

General principles:

Uncomplicated appendicitis (perioperative prophylaxis):

Complicated appendicitis (perforated, abscess, peritonitis)—community-acquired, mild-moderate:

Severe/healthcare-associated/septic:

Penicillin allergy:

Antibiotics-only (non-operative) protocol (CODA trial regimen):

Adjuncts:

Surgical Management and Procedural Considerations

— Lower wound infection rate, shorter LOS, faster return to work vs. open

— Allows pelvic/gynecologic survey in women

— Equivalent or superior outcomes in obese and elderly

— Surgeon expertise unavailable, severe adhesions from prior surgery, hemodynamic instability precluding pneumoperitoneum, perforation with extensive contamination (sometimes)

— Confirm appendicitis; if normal appendix found, still remove it (avoids future diagnostic confusion) and explore for Meckel's, mesenteric adenitis, gynecologic pathology

— Send appendix to pathology—~1% incidence of neoplasm (carcinoid most common); appendix tip carcinoids <1 cm cured by appendectomy alone

— Perforated with peritonitis: appendectomy + thorough irrigation + drain placement selectively

— Phlegmon/abscess: many surgeons defer to percutaneous drainage + IV antibiotics, then interval appendectomy at 6–8 weeks (controversial in patients without appendicolith)

— Image-guided drain for abscess >3–4 cm

— IV antibiotics 5–7 days, transition to PO

— Repeat imaging if not improving

— Advance diet as tolerated (often same day)

— Discharge typically <24 h

— Activity: light activity within days, full activity in 2 weeks

— Return precautions: fever, increasing pain, wound drainage, inability to tolerate PO

— Adults >40 should have colonoscopy before interval appendectomy to exclude cecal/appendiceal malignancy mimicking appendicitis

CCS pearl: After laparoscopic appendectomy for uncomplicated appendicitis, stop antibiotics, advance diet, ambulate, control pain, and discharge within 24 hours—ordering extended antibiotics or prolonged NPO costs points on the case.

Laparoscopic appendectomy = standard of care for adults:

Open appendectomy indications:

Intraoperative decisions:

Complicated cases — operative strategy:

Percutaneous drainage:

Postoperative pathway (uncomplicated lap appy):

Interval appendectomy considerations:

Special Populations — Elderly and Renal/Hepatic Impairment

— Present later, with vaguer symptoms—often without classic migration or fever

— Perforation rate at presentation >50% (vs. ~20% overall)

— Comorbidities (CAD, CKD, diabetes) raise perioperative risk

— Higher mortality (1–4% vs. <0.5% in young adults)

— Always consider underlying malignancy: cecal adenocarcinoma can obstruct appendiceal lumen and mimic appendicitis—colonoscopy within 6–8 weeks post-op recommended in adults >40 with complicated appendicitis

— Lower threshold for CT—exam unreliable

— If contrast contraindicated by CKD, non-contrast CT still useful; MRI alternative

— Cardiac risk stratification (RCRI); avoid delays for non-urgent workup if surgical urgency present

— Medication reconciliation: hold anticoagulants per ACCP guidelines; bridge if high thromboembolic risk

— Delirium prevention: minimize benzodiazepines, opioids; early mobilization, sleep hygiene

— Adjust antibiotics: piperacillin-tazobactam, cefoxitin, ertapenem all need renal dosing

— Avoid nephrotoxins (NSAIDs, IV contrast if eGFR <30 unless essential—use isotonic IV fluids and weigh risk)

— Watch for contrast-induced AKI; metformin held around contrast in CKD stage 4+

— Metronidazole accumulates in severe cirrhosis—reduce dose by 50% in Child-Pugh C

— Increased bleeding risk: correct coagulopathy preoperatively (vitamin K, FFP, platelets as indicated)

— Ascites complicates wound healing; consider postoperative diuresis and TIPS evaluation if applicable

Board pearl: In any adult >40 with complicated appendicitis, atypical CT findings, or appendicitis without obvious obstruction, schedule outpatient colonoscopy within 6–8 weeks—missed cecal malignancy is a classic Step 3 pitfall in the follow-up question.

Elderly patients (>65):

Imaging considerations:

Perioperative optimization in elderly:

Renal impairment:

Hepatic impairment:

Special Populations — Pregnancy and Other Subgroups

— Appendicitis is the most common non-obstetric surgical emergency in pregnancy (~1 in 1500)

— Appendix migrates superolaterally as uterus enlarges—RUQ pain possible in third trimester

— Diagnostic delay → fetal loss rate jumps from ~3–5% (uncomplicated) to 20–35% with perforation

— Step 1: Graded-compression ultrasound (sensitivity drops in third trimester)

— Step 2: MRI without gadolinium if US non-diagnostic

— Step 3: CT only if MRI unavailable and clinical suspicion remains high—benefit outweighs minimal fetal radiation risk

— Laparoscopic appendectomy is safe in all trimesters (SAGES guidelines)

— Left lateral decubitus tilt to relieve IVC compression

— Tocolytics not routinely needed; obstetric consultation for fetal monitoring

— Antibiotics: cephalosporins and metronidazole acceptable; avoid fluoroquinolones, tetracyclines

— Blunted inflammatory response; classic signs muted

— Lower imaging threshold; broader differential (typhlitis/neutropenic enterocolitis in chemo patients—non-operative management preferred for typhlitis)

— Atypical pathogens (CMV, fungal) on pathology in HIV

— Exam unreliable; CT essential

— Laparoscopy preferred (lower wound complications than open in obese)

— Terminal ileitis can mimic appendicitis; if appendix appears normal at surgery, examine TI carefully

— Removing a normal appendix in Crohn's is acceptable unless cecum is inflamed at the base (risk of fistula)

Step 3 management: A pregnant patient with RLQ pain → β-hCG confirmed, obstetric consult, ultrasound first, MRI if equivocal, surgical consult early. Do NOT delay surgery for diagnostic uncertainty in a sick-appearing pregnant patient—maternal sepsis is the bigger fetal threat.

Pregnancy:

Imaging algorithm in pregnancy:

Management in pregnancy:

Immunocompromised (HIV, chemo, post-transplant, chronic steroids):

Obesity:

Patients with Crohn's disease:

Complications and Adverse Outcomes

— Perforation: highest risk after 36–48 h of symptoms; leads to localized abscess, generalized peritonitis, or sepsis

— Appendiceal abscess: walled-off collection; managed with percutaneous drainage + antibiotics

— Phlegmon: inflammatory mass without drainable fluid; antibiotics + bowel rest

— Generalized peritonitis: diffuse rigidity, sepsis; surgical emergency after resuscitation

— Pylephlebitis: septic portal vein thrombophlebitis—rare, presents with fever, jaundice, hepatic abscesses; treat with anticoagulation + prolonged IV antibiotics

— Sepsis/septic shock: treat per Surviving Sepsis (fluids, antibiotics within 1 h, lactate, vasopressors as needed)

— Surgical site infection (2–5% uncomplicated, up to 20% perforated): erythema, drainage, fever post-op day 3–7

— Intra-abdominal abscess (more common after perforated cases): fever, leukocytosis, ileus 5–10 days post-op → CT and percutaneous drainage

— Ileus/small bowel obstruction: early ileus common; late SBO from adhesions

— Stump appendicitis: rare recurrence in retained appendiceal stump

— Fecal/enterocutaneous fistula: rare; suspect with persistent drainage

— Anesthesia/cardiac complications: especially in elderly

— Increased risk of future adhesive SBO (lower with laparoscopic approach)

— Recurrence rate ~40% at 5 years with antibiotics-only management

— Incidental appendiceal neoplasm (~1%): carcinoid (most common), goblet cell, mucinous, adenocarcinoma—management depends on size and pathology

— Overall <0.5%

— Rises to 2–4% with perforation in elderly

— Driven by sepsis, cardiac events, delayed presentation

Board pearl: A patient who returns 5–7 days post-appendectomy with fever, RLQ/pelvic pain, and leukocytosis has a postoperative intra-abdominal abscess until proven otherwise—order CT abdomen/pelvis with contrast and arrange interventional radiology drainage; do not reflexively reopen.

Disease-related complications:

Postoperative complications:

Long-term considerations:

Mortality:

When to Escalate Care — ICU, Consult, and Inpatient Triage

— Any patient with clinical or imaging diagnosis of appendicitis

— Equivocal imaging with high clinical suspicion

— Acute abdomen of unclear etiology

— Septic shock (lactate >4, vasopressor requirement, MAP <65 despite fluids)

— Generalized peritonitis with hemodynamic instability

— Respiratory failure or significant comorbidity decompensation

— Postoperative complications: ARDS, AKI requiring CRRT, hemodynamic instability

— Standard post-laparoscopic appendectomy if discharge criteria not met same day

— Complicated appendicitis on IV antibiotics ± drainage

— Comorbidity-related monitoring needs

— Uncomplicated appendectomy with same-day discharge if tolerating PO, pain controlled, ambulating, afebrile

— Antibiotics-only management for selected uncomplicated cases (with close follow-up)

— General surgery: primary

— Interventional radiology: abscess drainage

— Obstetrics: any pregnant patient

— Gynecology: when ovarian/tubal pathology cannot be excluded

— Infectious disease: complicated/healthcare-associated infections, immunocompromised, antibiotic failure

— Oncology/GI: incidental appendiceal neoplasm on pathology

— Critical access hospitals without surgical capability: stabilize, antibiotics, transfer

— Pediatric appendicitis: transfer to pediatric surgical center when feasible

— Pregnancy complications: transfer to facility with obstetric and neonatal capabilities if early gestation viability concerns

CCS pearl: On any case suggesting peritonitis or sepsis, the order set is: 2 large-bore IVs, isotonic fluid bolus, broad-spectrum IV antibiotics, blood cultures, lactate, CBC, BMP, type and screen, NPO, Foley, surgical consult, ICU admission for hemodynamic instability. Move the clock only after these are queued.

Immediate surgical consultation indications:

ICU admission criteria:

Inpatient floor admission:

Outpatient/observation pathway:

Consultations to consider:

Transfer considerations:

Key Differentials — Same-Category (GI) Causes

— Often post-viral, mimics appendicitis in young adults

— CT shows enlarged mesenteric nodes with normal appendix

— Self-limited; supportive care

— Subacute RLQ pain, diarrhea, weight loss, oral ulcers, perianal disease

— CT: terminal ileal wall thickening, mesenteric fat creeping, comb sign

— Colonoscopy/biopsy confirms

— "Rule of 2s": 2% population, 2 feet from ileocecal valve, 2 inches long, presents <2 years (classically)

— Adults can present with diverticulitis mimicking appendicitis; found at surgery

— Right-sided diverticulitis more common in Asian populations

— CT differentiates; management often non-operative

— Neutropenic patient (post-chemo) with RLQ pain, fever, diarrhea

— CT: cecal wall thickening

— Non-operative management: bowel rest, broad-spectrum antibiotics, G-CSF; surgery only for perforation/uncontrolled bleeding

— Diffuse crampy pain, prominent diarrhea, vomiting precedes pain

— Sick contacts, recent travel

— RUQ pain, Murphy's sign, gallstones on US

— Sudden onset, free air on imaging

— Distension, vomiting, obstipation; prior surgery is biggest risk factor

— Common in elderly; KUB shows stool burden

Key distinction: Terminal ileitis on CT in a young adult with chronic intermittent symptoms = Crohn's, not appendicitis. Terminal ileitis acutely in a young adult with diarrhea + sick contacts = Yersinia enterocolitica (treat supportively; do not remove a normal appendix if found at surgery with active terminal ileitis from Crohn's—risk of fistula at the inflamed cecal base).

Mesenteric adenitis:

Crohn's disease (terminal ileitis):

Meckel's diverticulitis:

Cecal diverticulitis:

Typhlitis (neutropenic enterocolitis):

Acute gastroenteritis:

Cholecystitis (subhepatic appendix mimic):

Perforated peptic ulcer:

Small bowel obstruction:

Constipation/stool impaction:

Key Differentials — Other-Category Causes

— Ectopic pregnancy: positive β-hCG, adnexal mass on US, possible hemodynamic instability—surgical emergency

— Ovarian torsion: sudden severe pain, nausea/vomiting, unilateral adnexal pain; US with Doppler shows decreased flow

— Ruptured ovarian cyst: mid-cycle, free fluid on US, usually self-limited

— PID/tubo-ovarian abscess: bilateral lower abdominal pain, cervical motion tenderness, fever, discharge; treat with ceftriaxone + doxycycline ± metronidazole

— Endometriosis: cyclic pain; chronic

— Ureteric colic (right): colicky flank-to-groin pain, hematuria, restless patient; CT shows stone

— Pyelonephritis: fever, CVA tenderness, pyuria

— UTI/cystitis: dysuria, frequency

— Ruptured/leaking AAA: elderly, hypotensive, pulsatile mass, back/flank pain—immediate vascular surgery

— Mesenteric ischemia: pain out of proportion to exam, lactate elevation, AFib history

— Aortic dissection: tearing chest/back pain, BP discrepancy

— Incarcerated/strangulated inguinal or femoral hernia: groin mass, bowel obstruction symptoms

— Appendiceal/cecal tumor obstructing lumen

— Lymphoma

— Right lower lobe pneumonia—obtain CXR in atypical presentations

— Rectus sheath hematoma (anticoagulation)

— Slipping rib syndrome

Board pearl: Pain out of proportion to exam + AFib + elevated lactate + minimal CT findings = acute mesenteric ischemia until proven otherwise—obtain CT angiography and consult vascular surgery emergently. This is a classic Step 3 misdirect when the stem suggests "appendicitis-like" pain in an older patient with cardiac history.

Gynecologic (mandatory in reproductive-age women):

Urologic:

Vascular:

Hernias:

Hematologic/oncologic:

Pulmonary referred pain:

MSK/abdominal wall:

Secondary Prevention, Discharge Medications, and Long-Term Plan

— Acetaminophen 650–1000 mg PO q6h scheduled

— Ibuprofen 400–600 mg PO q6h PRN (if no contraindication)

— Short course low-dose opioid (e.g., oxycodone 5 mg PO q4–6h PRN) for breakthrough pain—limit to 3–5 days, use state PDMP, counsel on disposal

— Stool softener (docusate) while on opioids

— Ondansetron PRN nausea

— No discharge antibiotics after uncomplicated appendectomy

— Complete oral antibiotic course (e.g., amoxicillin-clavulanate or ciprofloxacin + metronidazole) to total ~4–7 days post-source-control if transitioning from IV early

— Probiotics not routinely recommended; counsel on C. difficile signs

— Complete 10-day oral antibiotic course

— Clear return precautions: worsening pain, fever, vomiting, inability to tolerate PO

— Counsel on ~40% lifetime recurrence; surgery if recurrence

— Keep incisions clean and dry; showering allowed at 24–48 h; no submersion (baths, pools) for 2 weeks

— Recognize signs of SSI: erythema, drainage, increasing pain, fever

— No heavy lifting (>10 lb) or strenuous exercise for 2 weeks (lap) or 4–6 weeks (open)

— Return to desk work in 3–7 days; physical jobs in 2–4 weeks

— Pathology review at follow-up—if appendiceal neoplasm found:

— Carcinoid <1 cm at tip with negative margins: appendectomy curative

— Carcinoid >2 cm, at base, or with mesoappendiceal invasion: right hemicolectomy

— Mucinous neoplasms: surgical oncology referral

— Adults >40 with complicated appendicitis: outpatient colonoscopy within 6–8 weeks to exclude underlying malignancy

Step 3 management: Always include the opioid stewardship bundle at discharge: smallest effective quantity, PDMP check, written disposal instructions, and concomitant scheduled non-opioid analgesia. This is repeatedly tested under patient safety and prescribing competencies.

Discharge medications after uncomplicated laparoscopic appendectomy:

Discharge medications after complicated/perforated appendicitis:

Antibiotics-only management discharge:

Wound care:

Activity restrictions:

Long-term considerations:

Follow-Up, Monitoring, and Counseling

— 2 weeks post-op: wound check, pathology review, activity advancement

— 4–6 weeks post-op: functional recovery assessment; clear for full activity

— Earlier follow-up if complicated appendicitis, abscess drainage, or persistent symptoms

— Confirm appendicitis (avoids missed alternate diagnosis on negative appendectomy)

— Review for incidental neoplasm—document patient notification if positive

— Plan further workup or referral as needed

— Resolution of pain, tolerating regular diet, return of bowel function

— Wound healing without erythema/drainage

— Resolution of postoperative ileus

— In drained abscess: imaging to confirm resolution (often at 4–6 weeks)

— Fever >38.5°C

— Worsening or new abdominal pain

— Persistent vomiting, inability to tolerate PO

— Wound erythema, drainage, dehiscence

— Shortness of breath, calf swelling (PE/DVT)

— Bloody/black stools

— Recurrence risk (negligible after appendectomy; 40% over 5 years with antibiotics-only)

— VTE awareness during reduced mobility

— Smoking cessation if applicable—improves wound healing and reduces postoperative complications

— Nutrition: advance to regular diet as tolerated; high-fiber to prevent constipation while on opioids

— Return to driving: when off opioids and can perform emergency maneuvers without pain

— Age >40 with complicated appendicitis or atypical presentation: schedule colonoscopy 6–8 weeks post-recovery

— Age-appropriate CRC screening should resume per USPSTF (age 45–75)

CCS pearl: At follow-up, document pathology review, schedule any indicated colonoscopy, taper opioids, and reinforce return precautions. CCS rewards explicit follow-up appointments and patient education orders ("counsel patient on...") that close the loop on transitions of care.

Standard postoperative follow-up timeline:

Pathology review at follow-up (critical):

Monitoring parameters:

Red-flag symptoms warranting return to ED:

Counseling topics:

Colonoscopy referral (if indicated):

Ethical, Legal, and Patient Safety Considerations

— Risks: bleeding, infection, anesthesia complications, bowel/bladder injury, conversion to open, recurrence (with non-op), incidental findings, mortality (<0.5% baseline, higher with perforation/elderly)

— Alternatives: surgery vs. antibiotics-only (when applicable), risks/benefits of each

— Document shared decision-making, especially for non-operative pathway

— Adult without capacity (e.g., septic obtundation): proceed under implied/emergency consent if life-threatening

— Surrogate decision-maker for non-emergent components

— Adolescents: state-specific consent rules; pregnant minors often have independent decision-making

— Pregnant patient refusing surgery: counsel that maternal sepsis is the leading threat to fetus; document refusal with risks reviewed; involve ethics/obstetrics

— Jehovah's Witness: advance directive regarding blood products; document scope (whole blood, components, autologous salvage); plan blood-conservation strategies preoperatively

— ED → OR: ensure NPO, antibiotics given, consent signed, β-hCG documented

— OR → floor: clear postoperative orders, antibiotic stop dates, pain plan

— Hospital → home: pathology pending—establish a system to notify patient of results, especially for incidental neoplasm

— Antibiotics-only patients: ensure clear return precautions and scheduled follow-up

— Surgical complications/never events: disclose per institutional policy and state law

— Suspected abuse if patient presentation includes injuries inconsistent with history

— Surgical time-out, antibiotic prophylaxis timing, VTE prophylaxis, normothermia, glycemic control

— Opioid stewardship at discharge

— Document negative β-hCG before imaging in reproductive-age women

— Document reason for any imaging delay or non-operative trial

— Document pathology review and patient notification

Board pearl: A pending pathology result (e.g., appendiceal carcinoid) after discharge represents a classic missed-handoff sentinel event. The discharging team must have a closed-loop system to ensure patient notification and appropriate referral—Step 3 frequently tests this under patient safety/transitions-of-care competencies.

Informed consent essentials:

Capacity and emergency exceptions:

Pediatric and pregnancy edge cases:

Transitions of care—high-risk handoff points:

Mandatory reporting and disclosure:

Patient safety bundles:

Documentation pitfalls (malpractice prevention):

High-Yield Associations and Rapid-Fire Clinical Facts

— Appendix arises from posteromedial cecum at the convergence of taeniae coli

— Blood supply: appendicular artery (branch of ileocolic artery)—end artery → susceptible to ischemia

— Most common cause of obstruction in adults: fecalith; in children: lymphoid hyperplasia

— McBurney's → localized peritonitis from inflamed appendix

— Rovsing's → referred peritoneal irritation

— Psoas → retrocecal appendix

— Obturator → pelvic appendix

— Dunphy's → peritoneal irritation with cough

— CT sensitivity ~95%; appendiceal diameter >6 mm is the threshold

— US in pregnancy: graded compression

— MRI in pregnancy: no gadolinium

— Cover Gram-negatives + anaerobes

— Cefoxitin or ceftriaxone + metronidazole = workhorse combos

— STOP-IT trial: 4 days post-source-control is sufficient

— ~1% appendiceal neoplasm rate; carcinoid most common

— Carcinoid <1 cm at tip: appendectomy curative

— Carcinoid >2 cm or at base: right hemicolectomy

— Mucinous neoplasm rupture → pseudomyxoma peritonei

— Most common non-obstetric surgical emergency

— Lap appendectomy safe in all trimesters

— Perforation triples fetal loss

— Children perforate faster (~30% at presentation)

— Lymphoid hyperplasia after viral illness is common trigger

— Retrocecal: flank pain, mild RLQ tenderness

— Pelvic: dysuria, diarrhea, suprapubic pain

— Elderly: vague pain, often perforated at presentation

Key distinction: Negative appendectomy rate should be <5–10% with modern imaging. A higher rate suggests over-reliance on clinical assessment without imaging, while a near-zero rate may indicate over-imaging and missed surgical cases—a quality-improvement tension worth understanding for systems-based questions.

Anatomy/pathophysiology pearls:

Classic exam signs and what they mean:

Imaging pearls:

Antibiotic pearls:

Pathology pearls:

Pregnancy pearls:

Pediatric crossover (Step 3 still tests):

Atypical presentations:

Pylephlebitis: rare septic portal vein thrombosis—anticoagulation + prolonged antibiotics

Board Question Stem Patterns

— 22-year-old with 18 h of periumbilical pain migrating to RLQ, anorexia, low-grade fever, mild leukocytosis

— Best next step: CT abdomen/pelvis with IV contrast → laparoscopic appendectomy with prophylactic cefoxitin

— 28-year-old G2P1 at 22 weeks with RLQ pain, nausea

— Imaging: graded-compression US first → MRI without gadolinium if non-diagnostic

— Management: laparoscopic appendectomy, obstetric consult

— 45-year-old with 5 days of RLQ pain, palpable mass, fever, CT shows 5-cm abscess

— Best next step: IV antibiotics + percutaneous drainage → interval appendectomy 6–8 weeks; colonoscopy first because >40

— 75-year-old with 3 days of generalized abdominal pain, mild fever, perforation on CT

— Management: resuscitate, antibiotics, surgery; schedule outpatient colonoscopy to exclude cecal malignancy

— Day 6 post-appendectomy for perforated appendicitis: fever, RLQ pain, leukocytosis

— Diagnosis: intra-abdominal abscess → CT and IR drainage

— Post-appendectomy pathology shows 2.5-cm carcinoid at base

— Management: right hemicolectomy

— Healthy 30-year-old, uncomplicated CT, no appendicolith, prefers non-surgical

— Management: IV ertapenem → oral cefdinir/metronidazole for 10 days; counsel on 40% recurrence

— Reproductive-age woman with RLQ pain, positive β-hCG, free fluid on US

— Diagnosis: ruptured ectopic, not appendicitis

— Elderly with AFib, severe pain out of proportion, lactate elevated

— Diagnosis: acute mesenteric ischemia → CT angiography

Step 3 management: Pattern recognition for these stems: β-hCG first in women, imaging-driven diagnosis, time-to-OR matters, post-op fever = abscess until proven otherwise, pathology drives long-term management.

Stem 1 — Classic uncomplicated:

Stem 2 — Pregnant patient:

Stem 3 — Complicated with abscess:

Stem 4 — Elderly with vague presentation:

Stem 5 — Postoperative complication:

Stem 6 — Pathology surprise:

Stem 7 — Antibiotics-only candidate:

Stem 8 — Differential trap:

Stem 9 — Mesenteric ischemia trap:

One-Line Recap

Appendicitis in adults is a time-dependent surgical emergency diagnosed by CT (US/MRI in pregnancy), treated with laparoscopic appendectomy plus narrow perioperative antibiotic coverage of Gram-negatives and anaerobes, with non-operative pathways reserved for selected uncomplicated cases or initial control of abscess/phlegmon followed by interval consideration.

— Anorexia + migrating periumbilical→RLQ pain + low-grade fever; β-hCG mandatory in reproductive-age women

— CT with IV contrast is gold standard in non-pregnant adults; appendiceal diameter >6 mm + fat stranding confirms

— US first then MRI without gadolinium in pregnancy

— Uncomplicated: laparoscopic appendectomy within 12–24 h + single-dose prophylactic antibiotics (cefoxitin or cefazolin/metronidazole)

— Complicated with abscess: IV antibiotics + percutaneous drainage; consider interval appendectomy

— Complicated with peritonitis: resuscitate, broad-spectrum antibiotics, urgent surgery

— STOP-IT trial: 4 days post-source-control antibiotics suffice

— Adults >40 with complicated appendicitis → colonoscopy 6–8 weeks to exclude cecal malignancy

— Pathology review for incidental neoplasm (carcinoid most common); >2 cm or base location → right hemicolectomy

— Pregnant patients: delay = fetal loss; lap appendectomy safe in all trimesters

— Post-op fever day 5–7 = intra-abdominal abscess until proven otherwise

— Closed-loop pathology notification, opioid stewardship at discharge, documented shared decision-making for non-operative pathway, β-hCG documentation before imaging/OR

Board pearl: When uncertain on a Step 3 case, defaulting to early surgical consultation, appropriate imaging by population, timely antibiotics, and explicit follow-up for pathology and colonoscopy captures the core competencies tested—appendicitis remains the prototypic surgical abdomen for transitions-of-care and patient-safety scoring.

Diagnostic essentials:

Management essentials:

Don't-miss issues:

Step 3 systems issues: