Acute Surgical Abdomen Evaluation

Algorithm Steps

1. ▶

   Start

   Patient with Acute Abdominal Pain

   New-onset or acute worsening of abdominal pain requiring evaluation. Goal: Determine if surgical intervention needed and how urgently.

   1. ●

      Action

      Initial Stabilization & Assessment

      1) ABCs - ensure hemodynamic stability. 2) IV access, fluid resuscitation if needed. 3) Pain control (does NOT mask surgical findings). 4) NPO. 5) Labs: CBC, BMP, LFTs, lipase, lactate, UA, pregnancy test. 6) Type & Screen if surgery possible.

      1. ●

         Action

         Focused Physical Examination

         INSPECT: Distension, scars, visible peristalsis, hernias. AUSCULTATE: Bowel sounds (absent, high-pitched). PERCUSS: Tympany (obstruction), dullness (fluid). PALPATE: Guarding, rigidity, rebound, masses. Check: Hernial orifices, genitalia (males), rectal exam.

         1. ◆

            Decision

            Signs of Peritonitis?

            PERITONITIS: Involuntary guarding, board-like rigidity, diffuse rebound tenderness, absent bowel sounds, patient lying still (any movement hurts). If generalized peritonitis present → Immediate surgical consultation.

            1. ⚠

               Warning

               ⚠️ Atypical Presentations

               ELDERLY: Diminished pain, delayed presentation, may lack classic signs even with perforation. IMMUNOCOMPROMISED: Blunted inflammatory response. OPIOID USE: Masked symptoms. OBESITY: Difficult exam. Lower threshold for imaging in these populations.

            2. ●

               Action

               Immediate Surgical Consultation

               Generalized peritonitis = surgical emergency. Rapid imaging (may skip if unstable). Resuscitate en route to OR. Exploratory laparotomy. Common causes: Perforated viscus, mesenteric ischemia, ruptured AAA, strangulated bowel.

               1. ●

                  Action

                  Surgical Planning

                  EMERGENT (<1h): Perforation with peritonitis, ruptured AAA, mesenteric ischemia. URGENT (1-6h): Appendicitis, cholecystitis with sepsis, bowel obstruction with strangulation. SEMI-ELECTIVE (6-24h): Uncomplicated appendicitis, cholecystitis, some diverticulitis. Consider: Patient optimization, antibiotic timing, surgical approach.

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                     Outcome

                     Proceed to Surgery

                     Surgical intervention indicated. Appropriate timing based on urgency. Continue resuscitation perioperatively.

            3. ●

               Action

               Focused Imaging

               CT abdomen/pelvis with IV contrast: Gold standard for most acute abdominal presentations. Identifies: Free air, obstruction, appendicitis, diverticulitis, cholecystitis, AAA, etc. ALTERNATIVES: US for biliary (RUQ pain), pelvic (female), AAA screening. Plain X-ray: Free air (erect CXR), obstruction (bowel gas pattern).

               1. ◆

                  Decision

                  Key Imaging Findings?

                  FREE AIR: Perforation - needs surgery. OBSTRUCTION: SBO/LBO - often surgical. ISCHEMIA: Mesenteric ischemia - emergency surgery. CONTAINED: Appendicitis, cholecystitis, diverticulitis - often surgical. VASCULAR: AAA rupture/leak - emergency vascular surgery.

                  1. ●

                     Action

                     Free Air = Perforation

                     Free intraperitoneal air = perforated hollow viscus. Sources: Peptic ulcer, diverticulitis, appendix, colon cancer, trauma. Requires exploration (laparoscopic or open). Identify source, repair, washout.

                  2. ●

                     Action

                     Bowel Obstruction

                     SBO: Consider trial of conservative management if partial, no strangulation signs. Surgery if complete, closed-loop, ischemia, or fails to improve. LBO: Usually requires intervention - see specific algorithms. Assess for strangulation (closed loop, mesenteric edema, decreased enhancement).

                  3. ●

                     Action

                     Contained Inflammatory Process

                     APPENDICITIS: Usually appendectomy (lap or open). CHOLECYSTITIS: Lap cholecystectomy (see TG18). DIVERTICULITIS: Grade-dependent (see WSES algorithm). May be medical vs. surgical.

                  4. ●

                     Action

                     Vascular Emergency

                     AAA RUPTURE: Massive resuscitation, permissive hypotension, emergent OR (EVAR vs open). MESENTERIC ISCHEMIA: Revascularization (endovascular or open) + second-look laparotomy. Time-critical.

                  5. ●

                     Action

                     Non-Surgical Management

                     Some conditions managed medically: Uncomplicated diverticulitis, partial SBO (adhesive), gastroenteritis, pancreatitis (initially). Close monitoring. Clear criteria for failure → escalation to surgery.

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                        Outcome

                        Observation/Medical Management

                        Surgery not immediately indicated. Serial exams. Clear parameters for surgical consultation if deteriorates.