What is the initial management for a patient presenting with vomiting, abdominal pain, and hypotension in the emergency room?

Initial Management of Patient with Vomiting, Abdominal Pain, and Hypotension in the Emergency Room

Immediately establish IV access and begin aggressive fluid resuscitation with at least 30 mL/kg of isotonic crystalloid (normal saline or lactated Ringer's) within the first 3 hours, while simultaneously assessing for life-threatening causes including acute mesenteric ischemia, perforated viscus, and septic shock. 1, 2

Immediate Actions (First 15 Minutes)

Resuscitation Protocol

• Administer 1000-2000 mL isotonic saline bolus immediately for hypotension while establishing large-bore IV access 1
• Recline patient onto back to optimize venous return 1
• Apply supplemental oxygen if hypoxemic 1
• Obtain vital signs every 5-10 minutes during initial resuscitation, monitoring for tachycardia, fever, and respiratory rate as these predict serious complications 3

Critical caveat: The presence of bradycardia with hypotension (rather than expected tachycardia) suggests either beta-blocker use, profound septic shock with myocardial depression, or severe metabolic derangement from bowel necrosis 2, 4

Immediate Laboratory Tests

• Draw blood immediately for: 4, 2, 3
  • Lactate level (>2 mmol/L indicates irreversible intestinal ischemia with hazard ratio 4.1)
  • Blood gas analysis to detect metabolic acidosis
  • Complete blood count, comprehensive metabolic panel
  • Serum cortisol and ACTH if adrenal crisis suspected

Do not delay treatment while awaiting laboratory results - begin resuscitation immediately 1

Diagnostic Evaluation (Concurrent with Resuscitation)

Focused History

• Ask specifically about: 3, 2
  • Prior abdominal surgery (85% sensitivity for adhesive bowel obstruction)
  • Character of vomiting: bilious or feculent vomiting indicates mechanical obstruction
  • Timeline: 48-hour progression from epigastric pain to collapse suggests mesenteric ischemia
  • Medications: ACE inhibitors can cause bowel angioedema 5

Physical Examination Priorities

• Assess for peritoneal signs: rebound tenderness, guarding, rigidity indicating perforation or bowel necrosis 3, 2
• Severe abdominal pain out of proportion to physical findings is the hallmark of acute mesenteric ischemia - this is the most dangerous diagnosis 4, 2
• Abdominal distension with diminished bowel sounds suggests obstruction 3
• Digital rectal exam: empty rectum supports complete obstruction 3

Critical warning: Absence of peritonitis does NOT exclude bowel ischemia - lactate and blood gas are essential 3

Definitive Imaging

Obtain CT angiography of abdomen/pelvis with IV contrast immediately if acute mesenteric ischemia is suspected - every 6 hours of delay doubles mortality 4, 2, 3

CT will identify:

• Transition points in bowel obstruction
• Bowel wall thickening or pneumatosis indicating ischemia
• Free air indicating perforation
• Vascular occlusion in mesenteric vessels 3, 2

Vasopressor Support

If hypotension persists after initial 1-2 L fluid bolus:

Start norepinephrine at 0.05-3.3 mcg/kg/min as first-line vasopressor for septic shock 1, 6

• Titrate to maintain mean arterial pressure ≥65 mmHg 1
• Administer through central line when possible 6
• Continue fluid resuscitation concurrently - blood volume depletion must be corrected 6

Additional Supportive Measures

• Make patient NPO and place nasogastric tube for bilious vomiting or suspected obstruction 3
• Antiemetic therapy (ondansetron 4-8 mg IV) for persistent vomiting after ruling out obstruction 1, 3
• Obtain immediate surgical consultation for any patient with severe abdominal pain, hypotension, and peritoneal signs 2, 3

Special Consideration: Adrenal Crisis

If patient has known adrenal insufficiency or presents with hypotension refractory to fluids plus hyponatremia and hypoglycemia:

Administer hydrocortisone 100 mg IV bolus immediately, followed by 100-300 mg/day as continuous infusion 1

• Do not delay treatment for diagnostic confirmation 1
• Continue 3-4 L isotonic saline with initial infusion rate of 1 L/hour 1

Reassessment Strategy

Perform serial abdominal exams every 4-6 hours to detect development of peritonitis 3

Frequent reassessment should include: 1

• Heart rate, blood pressure, respiratory rate, temperature
• Urine output (goal ≥0.5 mL/kg/hr)
• Mental status
• Lactate trending

Signs of shock mandate immediate surgical exploration without delay - do not wait for imaging if patient is deteriorating 2, 3