27-year-old man presents with sudden severe epigastric and right upper quadrant abdominal pain that began one hour ago, accompanied by five episodes of vomiting and a brief witnessed tonic‑clonic seizure without incontinence. He now has shortness of breath, diaphoresis, blood pressure 150/90 mm Hg, heart rate in the 70s, respiratory rate 28, oxygen saturation 99% on room air, and temperature 36.3 °C. Physical exam reveals a soft, flat abdomen with epigastric and right upper quadrant tenderness, a positive Murphy’s sign, and no rebound tenderness. No past medical history, no prior surgeries, and no known drug or food allergies. Point‑of‑care glucose is 96 mg/dL and electrocardiogram shows sinus rhythm without ischemic changes. What is the assessment, differential diagnosis, and management plan?

Assessment and Management of Acute Epigastric/RUQ Pain with Seizure-Like Episode

Primary Assessment

This 27-year-old man requires immediate exclusion of life-threatening cardiac and gastrointestinal emergencies, with acute cholecystitis being the most likely diagnosis given the positive Murphy sign, but myocardial infarction and perforated peptic ulcer must be ruled out first. 1

The witnessed "seizure" episode (tonic-clonic movements without incontinence or post-ictal confusion) in the context of severe abdominal pain and diaphoresis is most consistent with a vasovagal syncope with convulsive movements rather than true epilepsy, particularly given the acute onset and lack of prior seizure history. 2

Immediate Diagnostic Workup

Cardiac Evaluation (First Priority)

• Obtain 12-lead ECG immediately (already done showing sinus rhythm without ST changes) and measure serial cardiac troponins at 0 hours and 6 hours—a single measurement is insufficient to exclude myocardial infarction, which presents atypically as epigastric pain in 10-20% of cases with this mortality rate if missed. 1, 3
• The tachypnea (RR 28), diaphoresis, and hypertension (150/90) could represent cardiac ischemia despite the normal initial ECG. 1

Laboratory Studies

• Complete blood count to detect leukocytosis suggesting cholecystitis, perforation, or ischemia. 4, 1
• Serum amylase (≥4× normal) or lipase (≥2× normal) to exclude acute pancreatitis with 80-90% sensitivity and specificity. 1, 3
• Serum lactate and comprehensive metabolic panel to assess for lactic acidosis (bowel ischemia), electrolyte disturbances, and dehydration from vomiting. 4
• C-reactive protein for inflammatory assessment. 1

Imaging Strategy

• Right upper quadrant ultrasound is the initial imaging study of choice for evaluating acute cholecystitis, with 96% accuracy for detecting gallstones and 88% sensitivity for acute cholecystitis. 5, 6
• The positive Murphy sign (focal tenderness over the sonographically localized gallbladder) combined with gallstones and wall thickening strongly suggests acute cholecystitis, though specificity is relatively low if pain medication was given. 5
• If ultrasound is negative or equivocal, obtain CT abdomen/pelvis with IV contrast to evaluate for perforated peptic ulcer (97% sensitivity for free air), pancreatitis, mesenteric ischemia, or other causes. 5, 1

Differential Diagnosis (Ranked by Likelihood and Severity)

Most Likely Diagnosis

1. Acute cholecystitis – positive Murphy sign, RUQ tenderness, vomiting, and appropriate age/gender make this the primary consideration. 5, 7, 8

Life-Threatening Alternatives to Exclude

1. Myocardial infarction – atypical presentation with epigastric pain, diaphoresis, and respiratory distress; 10-20% mortality if missed. 1, 3
2. Perforated peptic ulcer – sudden severe epigastric pain with vomiting; mortality reaches 30% if treatment delayed; CT shows free air in 97% of cases. 1, 3
3. Acute mesenteric ischemia – severe pain out of proportion to examination findings, though the soft abdomen makes this less likely; requires immediate CTA if suspected. 5
4. Acute pancreatitis – epigastric pain with vomiting, though typically radiates to back; check amylase/lipase. 1, 3

Other Considerations

1. Gastric outlet obstruction – persistent vomiting with epigastric pain; now most commonly caused by gastric cancer in adults. 3
2. Bowel obstruction – vomiting and epigastric pain, though the flat soft abdomen and absence of obstipation make this less likely. 4

Immediate Management

Resuscitation and Stabilization

• Maintain NPO status until surgical emergency is excluded. 4, 1
• Establish large-bore IV access and begin fluid resuscitation to correct dehydration from vomiting and enhance visceral perfusion. 5, 4
• Administer broad-spectrum antibiotics immediately if acute cholecystitis or perforation is suspected. 5

Symptomatic Treatment

• High-dose PPI therapy (omeprazole 40 mg once daily) for suspected acid-related pathology while awaiting definitive diagnosis. 1, 3
• Ondansetron 8 mg sublingual every 4-6 hours for nausea after confirming baseline ECG (risk of QTc prolongation), or promethazine 12.5-25 mg orally/rectally every 4-6 hours as alternative. 1, 3
• Avoid NSAIDs as they increase risk of peptic ulcer disease and bleeding. 4, 1

Surgical Consultation

• Obtain immediate surgical consultation given the combination of severe epigastric/RUQ pain, persistent vomiting, positive Murphy sign, and respiratory distress. 4
• Urgent laparotomy is indicated if peritonitis develops or imaging reveals perforation, ischemia, or complicated cholecystitis. 5, 4

Regarding the Seizure Episode

• The brief episode of stiffening and jerking without bowel/bladder incontinence, post-ictal confusion, or recollection loss lasting only seconds is most consistent with convulsive syncope secondary to severe pain and vasovagal response rather than true epilepsy. 2
• No anti-epileptic drugs are indicated for this single provoked event in the context of acute illness. 2
• If true seizure activity is suspected, video EEG monitoring would be required for definitive characterization, but this is not the priority given the acute abdominal emergency. 2

Critical Pitfalls to Avoid

• Do not assume biliary disease without excluding cardiac causes—missed MI carries 10-20% mortality. 1, 3
• Do not delay imaging based on normal initial ECG—serial troponins at 6 hours are mandatory. 1, 3
• Do not attribute the seizure-like episode to epilepsy without first addressing the acute abdominal pathology causing severe pain and potential vasovagal response. 2
• Do not postpone surgical consultation in a patient with severe pain, positive Murphy sign, and hemodynamic stress (tachypnea, hypertension, diaphoresis). 4
• Absence of fever does not exclude acute cholecystitis—early presentation may lack systemic inflammatory response. 5

Disposition

• Admit for observation with serial abdominal examinations every 4-6 hours regardless of initial imaging results. 4
• Continuous monitoring of vital signs, particularly for development of hypotension, fever, or worsening tachypnea suggesting progression to sepsis or perforation. 4
• Repeat imaging promptly if clinical deterioration occurs. 4