Acute Abdominal Pain

Acute Abdominal Pain

1. Notify for symptoms like bloating and tightness.
2. Abdominal pain.
3. Re-evaluation.

If unstable:

• Check for tachycardia, hypotension, signs of hypoperfusion, and signs of dehydration.
• If not stable, proceed to resuscitation.

If stable:

• Conduct a focused history and physical examination.
• Proceed with focused investigations.
• Determine if surgery consultation is needed.
• If not, proceed with definite medical treatment.
• Supportive treatment.

[1] Recognizing Impending Shock, Resuscitate

• Signs and symptoms of shock, especially tachycardia and narrow pulse pressure.

[2] Resuscitation:

• Evaluate ABCs and resuscitate as needed.
• Cardiac monitoring: BP, HR, SpO2, ± urine output monitoring (via Foley catheter).
• Lab tests: Electrolytes, BUN/Cr, CBC with platelet count, coagulation tests, blood typing, crossmatch if hemorrhage is suspected, LFT if hepatobiliary cause is suspected, urinalysis (for KUB system).
• If GI bleed is present, refer to the GI bleed section.
• Consider blood transfusion.
• If infection or sepsis is suspected, perform hemoculture and administer empirical antibiotics.

[3] Focused History Taking and Physical Examination:

• Take a detailed history, including any accompanying symptoms and physical examination, focusing on past medical history (especially hepatobiliary), surgical history (check for surgical scars), history of nausea/vomiting, alcohol consumption, UTI symptoms, NPO status, and examination of the groin area (rule out inguinal hernia with/without complications).
• For females with lower abdominal pain, always consider OB/GYN causes and perform a urine pregnancy test in women of childbearing age.
• Always rule out surgical causes.
• If a surgical condition is suspected, consult surgery urgently.
• Signs of peritonitis include rigidity, involuntary guarding, rebound tenderness (weaker signs than guarding), or if the patient prefers to lie still to avoid pain.
• Pain out of proportion (severe pain without signs) suggests an ischemic cause.
• Abrupt onset of severe pain or change in pain location (referred pain).
• Abdominal pain occurring before fever or vomiting.
• Bilious vomiting.
• Sudden onset of pallor (acute anemia) may indicate GI bleeding.

[4] Focused Investigation:

Laboratory Tests and Suspected Conditions:

• Amylase, Lipase: More specific for Pancreatitis.
• Serum β-HCG, Urine pregnancy test: Pregnancy, ectopic/molar pregnancy.
• Platelet count, Coagulogram: GI bleed, coagulopathy, chronic liver disease.
• Electrolytes: Dehydration, electrolyte imbalance.
• Glucose: DKA, pancreatitis.
• Hemoglobin/HCT: GI bleeding.
• Lactate: Mesenteric ischemia, sepsis.
• Liver function tests: Cholangitis, hepatitis, liver abscess, cholelithiasis.
• Renal function tests: Dehydration, AKI, CKD.
• Urinalysis: UTI, ureteric colic, pyelonephritis.
• ECG & Troponin: MI.
• Stool Exam: Inflammatory or infectious diarrhea.
• Acute Abdomen Series: Bowel obstruction, ileus, bowel perforation (pneumoperitoneum indicates surgical intervention), gallstone (10%), kidney stone (90%).
• Ultrasound: Cholecystitis, cholangitis, pancreatitis, liver abscess, intra-abdominal fluid collection, gynecologic conditions.
• CT Abdomen: Uncertain diagnosis.

[5] Supportive Treatment:

1. Anti-acid drug: Omeprazole (20 mg) 1 tablet orally before meals or, if severe, Omeprazole (40 mg) IV stat.
2. Anti-spasmodic drug: Hyoscine [Buscopan] 10 mg 1 tablet orally three times daily, or Hyoscine 20 mg IV stat.
3. Anti-emetics: Ondansetron 4 mg IV as needed every 4 hours; max 32 mg/day (Side Effect: headache), Metoclopramide 10 mg IV (Side Effect: extrapyramidal symptoms, EPS).
4. Analgesics: Morphine for severe pain 3-5 mg IV as needed every 4-6 hours.
5. Antibiotics: In cases of peritonitis or sepsis due to intra-abdominal infection, an empirical regimen of Ceftriaxone 2 g IV once daily + Metronidazole 500 mg IV every 8 hours.

Common Pitfalls:

• Failure to perform a pregnancy test or consider pregnancy-related causes.
• Overlooking aortic dissection or MI.
• Not recognizing that DKA can often present with abdominal pain.
• Omission of PR, PV, examination of the inguinal area when necessary.
• Being misled by lab values within the normal range that mask the diagnosis, despite clinical indications (over-reliance on lab values).
• Elderly and immunocompromised patient groups with unclear clinical presentations.

Life-Threatening Conditions:

• Ruptured or expanding aortic aneurysm.
• Aortic dissection/MI.
• Bowel perforation.
• Mechanical bowel obstruction.
• Acute mesenteric ischemia.
• Acute pancreatitis.
• Acute cholangitis.
• Ruptured ectopic pregnancy.