What is the management for abdominal pain with vomiting?

Management of Abdominal Pain with Vomiting

Begin with immediate hemodynamic assessment and check vital signs for tachycardia (≥110 bpm), hypotension, fever (≥38°C), or tachypnea, as these combinations predict life-threatening complications including anastomotic leak, bowel ischemia, perforation, or sepsis and mandate urgent intervention. 1

Immediate Assessment and Resuscitation

Hemodynamic Stabilization

• Start aggressive IV crystalloid resuscitation immediately for dehydration from vomiting 1
• Signs of shock (hypotension, altered mental status, tachycardia) mandate immediate surgical exploration without delay 1
• Tachycardia alone in post-surgical patients is a critical warning sign requiring aggressive investigation 1

NPO Status and Decompression

• Make patient NPO and place nasogastric tube for decompression if bilious or feculent vomiting is present, as this indicates mechanical obstruction 1
• Bilious vomiting specifically suggests bowel obstruction requiring immediate decompression 1

Critical History Elements

Surgical Red Flags

• Ask about prior abdominal surgery, which has 85% sensitivity and 78% specificity for adhesive small bowel obstruction (causes 55-75% of all small bowel obstructions) 1
• Inquire about timing: vomiting before pain makes appendicitis unlikely, while migratory pain to right lower quadrant suggests appendicitis 2

Pain Characteristics

• Severe pain out of proportion to physical findings suggests acute mesenteric ischemia until proven otherwise 1
• Sudden-onset severe epigastric pain radiating to the back with vomiting is classic for acute pancreatitis 3
• The triad of abdominal pain, constipation, and vomiting suggests sigmoid volvulus, particularly in elderly institutionalized patients on psychotropic medications 1

Alarm Symptoms

• Persistent vomiting is a red flag that excludes functional dyspepsia and mandates investigation for structural disease such as peptic ulcer disease or acute coronary syndrome 4
• Check for weight loss, anemia, dysphagia, hematemesis, or age >50 years with vascular risk factors 4

Physical Examination Priorities

Peritoneal Signs

• Assess for rebound tenderness, guarding, or rigidity, which indicate possible perforation or bowel necrosis 1
• Critical caveat: Absence of peritonitis does NOT exclude bowel ischemia—lactate and blood gas are essential 1

Specific Findings

• Abdominal distension with diminished bowel sounds is classic for bowel obstruction 1
• Empty rectum on digital examination supports complete obstruction 1
• Positive psoas sign or fever increases likelihood of appendicitis 2

Essential Laboratory Testing

Immediate Labs

• Order complete blood count, electrolytes, renal function, blood gas, and serum lactate to detect bowel ischemia 1
• Check serum amylase (≥4x normal) or lipase (≥2x normal) to exclude acute pancreatitis, with sensitivity and specificity of 80-90% 4
• Obtain C-reactive protein, as elevated levels predict postoperative complications 1
• Liver function tests and serum albumin in appropriate contexts 1

Cardiac Evaluation

• Obtain ECG to exclude myocardial ischemia, particularly in women, diabetics, and elderly patients who may present atypically with epigastric pain and vomiting 4
• Myocardial infarction can present with epigastric pain and has 10-20% mortality if missed 4

Imaging Strategy

Initial Imaging

• Plain abdominal radiograph is the initial test but has limited sensitivity—negative films do NOT exclude mesenteric ischemia or early obstruction 1
• Plain films can show extraluminal gas (97% of perforations), but CT is definitive 4

Definitive Imaging

• CT abdomen/pelvis with IV contrast is the definitive test for identifying obstruction, transition points, bowel ischemia, and surgical causes 1
• CT helps distinguish mechanical obstruction from functional bloating and prevents unnecessary laparotomy 1
• For suspected mesenteric ischemia, obtain immediate CT angiography and surgical consultation without delay 1

Alternative Imaging

• Ultrasound can be performed first in a step-up approach, with CT after inconclusive or negative US 2
• MRI has 94% sensitivity and 96% specificity for acute appendicitis but is not routinely available emergently 2

Pharmacologic Management

Antiemetic Therapy

• Administer ondansetron 8 mg sublingual every 4-6 hours, promethazine 12.5-25 mg orally/rectally every 4-6 hours, or prochlorperazine 5-10 mg every 6-8 hours 4
• Obtain baseline ECG before administering ondansetron due to QTc prolongation risk 4
• Caution with promethazine and prochlorperazine in elderly patients due to anticholinergic effects and CNS depression 1
• Ondansetron 4 mg IV over 2-5 minutes is effective for postoperative nausea/vomiting 5

Acid Suppression

• Start high-dose proton pump inhibitor therapy immediately with omeprazole 20-40 mg once daily before meals while awaiting diagnostic workup 4
• Full-dose PPI therapy is first-line for ulcer-like dyspepsia, with healing rates of 80-90% for duodenal ulcers and 70-80% for gastric ulcers 4

Specific Clinical Scenarios

Suspected Bowel Obstruction

• Obtain CT to identify transition point and assess for ischemia 1
• Perform serial abdominal exams every 4-6 hours to detect peritonitis 1
• Prior surgery history strongly suggests adhesive obstruction 1

Suspected Mesenteric Ischemia

• This is a life-threatening condition with mortality reaching 30-40% in necrotizing cases 4
• Immediate CT angiography and surgical consultation without delay 1
• Particularly suspect in elderly patients with vascular risk factors and pain out of proportion to examination 4

Suspected Acute Pancreatitis

• Overall mortality <10% but reaches 30-40% in necrotizing pancreatitis 4
• Epigastric pain radiating to back is the classic distinguishing feature 3
• Opioid medications are the mainstay of pain management 3

Suspected Perforation

• Extraluminal gas on CT is present in 97% of perforations 4
• Sudden, severe epigastric pain that generalizes, accompanied by fever and abdominal rigidity, requires immediate surgical intervention 4
• Perforation has mortality up to 30% 4

Elderly Patients

• Clinical presentation is often atypical, with only 43-48% having positive Murphy's sign and 36-74% having fever 1
• CT imaging is critical for diagnosis due to atypical presentations 1
• Higher rates of leucocytosis (41.2%) and elevated CRP (64.1%) compared to younger patients 1

Common Pitfalls to Avoid

• Delaying endoscopy in patients with alarm features (persistent vomiting, weight loss, anemia, dysphagia) can lead to poor outcomes 4
• Missing cardiac causes of epigastric pain can be fatal 4
• Assuming absence of peritonitis excludes bowel ischemia—always check lactate and blood gas 1
• Relying on negative plain films to exclude serious pathology 1
• Attributing persistent vomiting to functional disease without investigation 4