Approach to the Management of Acute Abdomen

Presenting Complaint and History of Presenting Complaint

When evaluating a patient with acute abdominal pain(acute abdomen), begin by understanding the presenting complaint and its history. This involves a systematic approach to gather relevant details about the pain and associated symptoms.

Onset

Determine when the pain began. Was it sudden, gradual, or rapid in onset? Sudden onset may indicate conditions like perforation or rupture, while gradual onset could suggest inflammation or obstruction.

Duration

Identify the timing of the symptoms. Do they occur at specific times, such as at night, in the morning, or persistently throughout the day? This can provide clues about the underlying cause.

Progression

Assess whether the pain is worsening, improving, or remaining stable. Note any factors that alleviate or exacerbate the symptoms.

Aggravating Factors

Ask about activities, foods, or positions that worsen the pain. For example, eating may aggravate peptic ulcer disease, while movement might worsen musculoskeletal pain.

Radiation

Determine if the pain radiates to other areas. For instance:

• Pain radiating to the left arm may suggest cardiac ischemia.
• Pain radiating to the groin is often associated with ureteric colic, such as from kidney stones.

Relieving Factors

Identify any actions or substances that provide relief, such as antacids, specific positions, or rest.

Severity

Ask the patient to rate the pain on a scale of 1 to 10 to gauge its intensity.

Site

Pinpoint the anatomical location of the pain. Is it localized to a specific region, or is it diffuse?

Associated Symptoms

Inquire about additional symptoms such as nausea, vomiting, fever, or changes in bowel habits. Persistent vomiting, for example, may indicate an obstruction or severe inflammation.

Systemic Signs and Symptoms of Acute abdomen

Evaluate for systemic indicators such as fever, jaundice, weight loss, or anorexia, which may suggest an underlying systemic condition.

Upper Gastrointestinal Symptoms

Look for signs like dysphagia, heartburn, nausea, vomiting, or hematemesis, which may point to upper GI tract issues.

Lower Gastrointestinal Symptoms

Note symptoms such as diarrhea, constipation, rectal bleeding, or steatorrhea, which could indicate lower GI tract involvement.

Genitourinary Symptoms

Ask about urinary frequency, dysuria, or hematuria, which may suggest genitourinary conditions like infections or stones.

Gynecological Symptoms

For female patients, inquire about menstrual history, including the length of periods, amount of bleeding, and any irregularities.

Past Medical History, Drug History, Family History, and Social History

Gather comprehensive details about the patient’s medical background, current medications, family history of similar conditions, and social factors such as alcohol or tobacco use.

Character of Pain

Describe the nature of the pain. It may be:

• Burning
• Stabbing or crushing
• Gripping or heavy
• Pricking
• Dull
• Colicky
• Throbbing

General Physical Examination and Abdominal Examination

Conduct a thorough general physical examination followed by a detailed abdominal assessment. Look for signs of tenderness, distension, guarding, or rebound tenderness.

Gestures to Describe Pain

Observe the patient’s gestures, as they can provide valuable clues:

• Squeezing the chest may indicate cardiac pain.
• Hand placement over the flank suggests renal colic.
• Rubbing the sternum often describes heartburn.
• Rubbing the buttock or thigh may point to sciatica.
• Clutching the abdomen is typical of mid-gut colic.

By systematically addressing these aspects, clinicians can effectively evaluate and manage patients presenting with acute abdominal pain.

Acute Coronary Syndrome (ACS)

Symptoms

• Heavy, dull, pressure/squeezing sensation in the chest.
• Substernal or epigastric pain with radiation to the left shoulder.
• Nausea, vomiting.
• Diaphoresis (excessive sweating), anxiety.
• Dizziness, lightheadedness, syncope (fainting).
• Pain may improve with nitroglycerin.

Diagnostic Findings

• ECG: Nonspecific changes, ST-segment elevation/depression, T-wave inversions, Q waves.
• Lab: Increased or normal troponin levels.
• Transthoracic Echocardiography (TTE): Hypokinesis, regional wall motion abnormalities.

Acute Mesenteric Ischemia

Symptoms

• Age >60 years, embolic risk factors (e.g., atrial fibrillation, thrombophilia), cardiovascular disease.
• Pain out of proportion to physical findings.
• Severe, diffuse abdominal pain and distention.
• Vomiting, diarrhea.
• Melena (black, tarry stools), hematochezia (bright red blood in stool).

Diagnostic Findings

• Labs: Lactic acidosis, hyperkalemia, leukocytosis.
• X-ray Abdomen: Normal in early stages; pneumatosis intestinalis in late stages.
• CT Angiography: Mesenteric arterial narrowing or occlusion, thickening of bowel wall, nonenhancing segments of solid organs or bowel wall, pneumatosis intestinalis.

Rupture or Impending Rupture of Abdominal Aortic Aneurysm (AAA)

Symptoms

• Age >50 years.
• Sudden, severe central abdominal, chest, or back pain.
• Hypotension, shock.
• Palpable mass in the midline of the abdomen.
• Grey Turner sign (flank bruising), Cullen sign (periumbilical bruising).
• History of atherosclerosis, hypertension, or smoking.

Diagnostic Findings

• Imaging: Recommended only for hemodynamically stable patients with low pretest probability.
• US Whole Abdomen: Aortic dilatation, periaortic fluid, intraperitoneal free fluid.
• CT/CTA Angiography: Retro- and intraperitoneal hemorrhage; localization of rupture/leak.

Perforation & Peritonitis

Symptoms

• Sudden onset of diffuse abdominal pain.
• Nausea, vomiting.
• Constipation or obstipation.
• Diffuse abdominal guarding, rigidity, and rebound tenderness.
• Absent bowel sounds.
• Loss of liver dullness on RUQ percussion.

Diagnostic Findings

• Abdominal X-ray: Pneumoperitoneum.

Aortic Dissection

Symptoms

• Sudden onset of severe, sharp tearing chest or abdominal pain with radiation.
• Hypotension, syncope, neurological symptoms.
• Asymmetrical blood pressure, pulse deficit.
• New diastolic murmur (aortic regurgitation).
• Symptoms of myocardial ischemia.

Diagnostic Findings

• Labs: Elevated D-dimer.
• ECG: Nonspecific ST-segment changes.
• CXR: Widening of the aorta.
• CT Angiography: Intimal flap with false lumen.
• Echocardiography: Proximal aortic dissection, tamponade, aortic regurgitation.

Acute Appendicitis

Symptoms

• Pain in the iliac fossa (McBurney’s sign positive).
• RLQ, epigastric, or periumbilical pain (migrating pain).
• Fever, nausea, anorexia.
• Guarding, tenderness, and rebound tenderness in the RLQ.

Diagnostic Findings

• Labs: Neutrophilic leukocytosis.
• Abdominal CT Scan: Distended appendix with periappendiceal fat stranding.
• US Whole Abdomen: Noncompressible, distended appendix with RLQ tenderness.

Mechanical Bowel Obstruction

Symptoms

• Colicky abdominal pain.
• Obstipation or bloating.
• Progressive nausea and vomiting (late finding).
• Diffuse abdominal distention, tympanic abdomen.
• Tinkling bowel sounds.
• History of abdominal surgery.

Diagnostic Findings

• X-ray Abdomen: Dilated bowel loops, absent rectal shadow, air-fluid levels.
• CT Abdomen: Similar findings; identifies obstruction site.

Symptomatic Cholelithiasis

Symptoms

• Biliary colic: RUQ pain radiating to the right shoulder.
• Postprandial onset.
• Nausea, vomiting.
• Normal abdominal examination.

Diagnostic Findings

• US Whole Abdomen: Gallstones with posterior acoustic shadow.

Choledocholithiasis

Symptoms

• RUQ pain.
• Features of obstructive jaundice.
• Nausea, vomiting.
• Normal abdominal examination.

Diagnostic Findings

• Labs: ↑ ALP, AST, ALT, total bilirubin.
• US Whole Abdomen: Dilated CBD, intrahepatic biliary dilatation, echogenic CBD structure.
• MRCP/ERCP: Filling defect in the contrast-enhanced duct.

Acute Pancreatitis

Symptoms

• Severe epigastric pain radiating to the back.
• Nausea, vomiting.
• Epigastric tenderness, guarding, rigidity.
• Hypoactive bowel sounds.
• History of gallstones or alcohol use.

Diagnostic Findings

• Labs: ↑ Lipase, amylase; hypocalcemia (poor prognosis).
• US Whole Abdomen: Pancreatic edema, peripancreatic fluid, gallstones.
• Abdominal CT: Pancreatic edema, peripancreatic fat stranding, gallstones.

Acute Cholecystitis

Symptoms

• Severe RUQ pain.
• Fever, chills, nausea, vomiting.
• Right shoulder referred pain.
• Murphy’s sign.

Diagnostic Findings

• CBC: ↑ WBC.
• US Whole Abdomen: Sonographic Murphy sign, gallbladder wall thickening.
• HIDA Scan: Nonvisualization of the gallbladder.

Acute Cholangitis

Symptoms

• Charcot triad: RUQ pain, fever, jaundice.
• Reynold’s pentad (Charcot triad + hypotension and altered mental status).

Diagnostic Findings

• Labs: ↑ WBC, CRP, ALP, AST, ALT, GGT, bilirubin; positive blood cultures.
• US Whole Abdomen: Biliary dilation, bile duct wall thickening.
• MRCP/ERCP: Obstruction findings.

Diverticulitis

Symptoms

• Fever.
• LLQ pain.
• Constipation.
• Tender LLQ mass.

Diagnostic Findings

• CBC: ↑ WBC.
• CT Abdomen: Colonic diverticula with periodic fat stranding.

Ruptured Ectopic Pregnancy

Symptoms

• Sudden severe lower abdominal pain.
• Vaginal bleeding or amenorrhea.
• Lower abdominal guarding and tenderness.
• Cervical motion tenderness.
• Tachycardia, hypotension.

Diagnostic Findings

• Labs: ↑ Beta-hCG.
• US: Free fluid in Morison’s pouch or pouch of Douglas; empty uterine cavity, adnexal mass.

Ovarian Torsion

Symptoms

• Sudden unilateral lower abdominal or pelvic pain.
• Nausea, vomiting.
• Unilateral iliac fossa tenderness.

Diagnostic Findings

• Pelvic US with Doppler: Enlarged, edematous ovary with decreased blood flow.
• CT Pelvis: Thickened ovarian tube, whirlpool sign.

Testicular Torsion

Symptoms

• Severe testicular and lower quadrant pain.
• Nausea, vomiting.
• Abnormally elevated testis.

Diagnostic Findings

• Doppler US: Twisted spermatic cord, reduced testicular perfusion.

Acute Pyelonephritis

Symptoms

• High fever, chills.
• Flank pain with costovertebral angle tenderness.
• Dysuria, frequency, urgency.

Diagnostic Findings

• Labs: ↑ WBC, CRP, ESR; positive urinalysis and urine culture.
• US KUB: Renal edema, hypoechogenic areas.
• CT Pelvis: Focal hypoenhancement.

Nephrolithiasis

Symptoms

• Severe unilateral colicky flank pain.
• Hematuria.
• Nausea, vomiting.
• Dysuria, frequency, urgency.

Diagnostic Findings

• Urinalysis: Gross or microscopic hematuria.
• CT Abdomen: Non-enhanced CT is gold standard.
• US: Preferred for radiation-sensitive patients.

Diagnostic Approach to Acute Abdomen

The initial imaging modality should be guided by the working diagnosis, based on the patient’s history, vital signs, and physical examination.

A. Imaging Modalities for acute abdomen

1. X-Ray Abdomen

• Positions: Erect and supine.
• Findings:
  • Gas under the diaphragm (due to gut perforation).
  • Dilated loops of bowel or fluid levels (due to intestinal obstruction).

2. US Whole Abdomen

• Purpose: To rule out:
  • Gallstones (cholelithiasis).
  • Cholecystitis.
  • Pancreatitis.

B. Laboratory Tests of acute abdomen

• Serum glucose.
• Liver function tests (LFTs), PT/INR.
• Urea, creatinine, and electrolytes.
• Serum amylase and lipase.
• Urine dipstick and culture/sensitivity (D/R and C/S).
• For females: Urine pregnancy test / β-hCG urine test.
• Blood gas analysis.
• Lactate, CRP, ESR.
• Troponin.
• Blood culture.

C. Differential Diagnosis of Acute abdomen

1. Acute Pancreatitis

• Symptoms:
  • Epigastric pain with tenderness.
  • No relief with ordinary treatment.
• Diagnostic Workup:
  • CBC, serum amylase.
  • ECG (to rule out MI/Angina in middle-aged patients).
  • Murphy’s sign (to exclude cholecystitis).
• Rule Out:
  • Cystitis and UTI: Burning sensation, micturition, suprapubic tenderness/pain.
  • Pyelonephritis: Abdominal pain, fever, renal angle tenderness, WBC in urine analysis.
  • Diabetic ketoacidosis (DKA): Check urine for glucose and ketones.

2. Ectopic Pregnancy (Classic Triad)

• Symptoms:
  • Amenorrhea.
  • Vaginal bleeding.
  • Abdominal pain.
• Diagnostic Workup:
  • Transabdominal/transvaginal ultrasound.

3. Pelvic Inflammatory Disease (PID)

• Symptoms:
  • Lower abdominal pain in sexually active women.
  • Vaginal discharge.

4. Peptic Ulcer Disease (PUD)

• Symptoms:
  • Clinical features + history of NSAID use.
• Diagnostic Workup:
  • Stool test for H. pylori (if positive, treat with triple therapy).

5. Fever + Abdominal Pain

• Always Consider Infectious Causes:
  • Cholecystitis.
  • Liver abscess.
  • Pyelonephritis.

Radiological Approach to Acute Abdomen

The initial imaging modality should be guided by the working diagnosis, based on the patient’s history, vital signs, and examination. The following recommendations apply to non-pregnant adults. In pregnant women with acute abdominal pain, ultrasound and/or MRI of the abdomen without contrast are the preferred initial imaging modalities.

Red Flags in Abdominal Pain

Management of Acute Abdomen

The management of acute abdomen involves a systematic approach to stabilize the patient, relieve symptoms, and address the underlying cause. Below is a detailed guide:

Initial Management of acute abdoment

1. Maintain ABCDE

• A: Airway.
• B: Breathing.
• C: Circulation.
• D: Disability (neurological status).
• E: Exposure (full body examination).

2. NPO (Nil Per Os)

• Keep the patient nil by mouth until further evaluation.

3. IV Access

• Pass two large-bore IV lines for fluid resuscitation and medication administration.

4. IV Fluid Resuscitation

• Options:
  • Ringer lactate.
  • Normal saline 0.9%.
  • Dextrose 5%.

5. Hemodynamic and Respiratory Support

• Monitor and stabilize blood pressure, heart rate, and oxygen saturation.
• Consider Inj. Haemaccel 500ml IV SOS for hypotension/shock.

6. Nasogastric Tube (NG) and Foley’s Catheter

• Insert NG tube for decompression if indicated.
• Foley’s catheterization for urine output monitoring.

7. Vital Monitoring

• Check:
  • Blood pressure (BP).
  • Pulse rate (PR).
  • Respiratory rate (RR).
  • Temperature.
  • SpO2.
  • Bedside RBS (random blood sugar).

8. Laboratory Tests

• Send for:
  • CBC.
  • Urea, creatinine, and electrolytes.
  • LFTs.
  • PT/INR.
  • Arterial blood gases (ABGs).

9. Focused History and Physical Examination

• Perform a detailed history and targeted physical examination.

10. Targeted Diagnostics

• Perform further tests (e.g., imaging, specific lab tests) as required.

11. Early Surgical Consult

• Involve a surgeon early for potential surgical intervention.

Supportive Care of Acute abdomen

1. IV Analgesics for Pain Management (In acute abdomen)

• Options:
  • Inj. Ketorolac 30mg/ml (Toradol): 4ml in 0.9% NS IV.
  • Inj. Tramadol 100mg/2ml (Tramol): IV for severe pain.
  • Inj. Nalbuphine 10mg/ml or 20mg/ml (Kinz): Dilute in 8ml 0.9% NS or DW, give slow IV.
  • Inj. Dimenhydrinate 50mg/ml (Gravinate): Dilute in 100ml 0.9% NS or Dextrose 5%.

2. Antipyretics for Fever

• Inj. Paracetamol 1g/100ml (Provas): IV SOS/TDS (maximum 4 infusions/day).

3. Antispasmodics for Spasmodic Abdominal Pain

• Options:
  • Inj. Drotavetine 40mg/2ml (Nospax): IV stat/TDS in 100ml 0.9% NS.
  • Inj. Phloroglucinol 40mg + Trimethylphloroglucinol 0.04mg/4ml (Spasion, Spasrid, Anafortan Plus): Dilute in 100ml 0.9% NS or Dextrose 5% BD/TDS.

4. Proton Pump Inhibitors (PPIs)

• Inj. Omeprazole 40mg/vial (Ruling, Risek): Dilute in 10ml 0.9% NS IV OD.

Empiric Antibiotic Therapy for Intra-Abdominal Infection

1. First-Line Options

• Inj. Metronidazole 500mg/100ml (Flagyl): IV TDS.
• Plus one of the following:
  • Inj. Ceftriaxone 1g (Titan, Rocephin): IV BD.
  • Inj. Cefuroxime 750mg (Zinacef, Zecef): IV BD/TDS.
  • Inj. Ciprofloxacin 200mg/100ml or 400mg/100ml (Novidate, Ciplet): IV BD.
  • Inj. Levofloxacin 750mg/150ml (Leflox, Qumic): IV OD.
  • Inj. Moxifloxacin 400mg/250ml (Moxiget, Mofest): IV OD.

2. For Severe Infection or High-Risk Patients

• Options:
  • Inj. Imipenem-cilastatin 500mg-1g (Cilapen, Tieman, Cilenem): IV TDS.
  • Inj. Meropenem 1g (Meronem, Meroget, Penro): IV TDS.
  • Inj. Piperacillin-tazobactam 4.5g (Tarzo, Tazocin EF, Tazbac): IV TDS.

Antiemetics for Vomiting in Acute abdomen

1. First-Line Options

• Inj. Dimenhydrinate 50mg/1ml (Gravinate): IV TDS.
• Inj. Metoclopramide 10mg/2ml (Maxolon, Metaclon): IV TDS (risk of EPS).

2. For Uncontrolled/Severe Vomiting

• Inj. Ondansetron 8mg/4ml (Onset, Onseron): Dilute in 50-100ml 0.9% NS over 15-20 minutes.

Identify and Treat the Underlying Cause of Acute abdomen

• Perform targeted diagnostics (e.g., imaging, endoscopy) to identify the cause.
• Initiate specific treatment based on the diagnosis (e.g., surgery for perforation, antibiotics for infection).

Also read:

https://www.uptodate.com/contents/evaluation-of-the-adult-with-abdominal-pain

https://www.ncbi.nlm.nih.gov/books/NBK459328