What is the initial management for a 65kg female patient presenting to the surgery ER with vomiting and abdominal pain?

Initial Management of Acute Abdominal Pain and Vomiting in the Surgery ER

Immediately assess hemodynamic stability (vital signs: heart rate, blood pressure, respiratory rate, temperature, oxygen saturation), establish IV access with aggressive crystalloid resuscitation, make the patient NPO, insert a nasogastric tube for decompression if bilious vomiting is present, obtain stat labs (CBC, electrolytes, renal function, lactate, blood gas), and order a CT abdomen/pelvis with IV contrast while performing a focused physical exam for peritoneal signs. 1

Immediate Vital Signs Assessment and Resuscitation

Check for critical warning signs that mandate immediate action:

• Tachycardia ≥110 bpm is the single most important predictor of serious complications including bowel ischemia, anastomotic leak, or sepsis—even in the absence of other signs 2, 1
• Hypotension, fever ≥38°C, tachypnea, or respiratory distress indicate potential sepsis or shock 2, 1
• Signs of shock (tachycardia + hypotension + altered mental status) mandate immediate surgical exploration without delay 1

Critical caveat: Patients on beta-blockers may not mount tachycardia despite serious pathology—maintain high suspicion 2

Initial Orders to Write Immediately

1. NPO Status and NG Tube

• Make patient strictly NPO (nothing by mouth) 1
• Insert nasogastric tube for decompression if bilious or feculent vomiting is present—this indicates mechanical obstruction 1

2. IV Fluid Resuscitation

• Start aggressive IV crystalloid resuscitation (e.g., 1-2 liters normal saline or lactated Ringer's bolus for a 65kg patient) to correct dehydration from vomiting 1
• Reassess volume status and continue fluid replacement based on clinical response 1

3. Laboratory Tests (Stat)

• Complete blood count, comprehensive metabolic panel (electrolytes, renal function), liver function tests 1
• Arterial or venous blood gas and serum lactate—essential for detecting bowel ischemia even when peritonitis is absent 1
• C-reactive protein to predict complications 1

Critical caveat: Elevated lactate and metabolic acidosis suggest bowel ischemia or necrosis—do not wait for peritoneal signs 2, 1

4. Imaging

• Order CT abdomen/pelvis with IV contrast immediately—this is the definitive diagnostic test 1
• CT identifies: obstruction with transition point, bowel ischemia, perforation, and other surgical emergencies 1
• Do not rely on plain abdominal X-ray alone—it has limited sensitivity and negative films do NOT exclude mesenteric ischemia or early obstruction 1

If IV contrast is contraindicated (allergy, acute kidney failure), proceed directly to diagnostic laparoscopy 2

Focused Physical Examination

Examine specifically for:

• Peritoneal signs (rebound tenderness, guarding, rigidity)—indicate possible perforation or bowel necrosis requiring immediate surgery 2, 1
• Abdominal distension with diminished or absent bowel sounds—classic for bowel obstruction 2, 1
• Digital rectal exam: empty rectum supports complete obstruction 1
• Severe pain out of proportion to physical findings—suggests acute mesenteric ischemia until proven otherwise 1

Critical caveat: Absence of peritonitis does NOT exclude bowel ischemia—lactate and imaging are mandatory 1

History Taking (While Resuscitation Proceeds)

Ask specifically about:

• Prior abdominal surgery—has 85% sensitivity for adhesive small bowel obstruction, which causes 55-75% of all small bowel obstructions 1
• Character of vomiting: bilious or feculent vomiting indicates mechanical obstruction 1
• Timing: postprandial vomiting suggests obstruction 3
• Associated symptoms: constipation, absence of flatus (90% in large bowel obstruction), bloody stools 2

Antiemetic Therapy

Consider ondansetron 4 mg IV over 2-5 minutes for symptomatic relief 4

• FDA-approved for postoperative nausea/vomiting with proven efficacy 4
• However, antiemetic use should not delay definitive diagnosis or surgical intervention 1

Serial Monitoring

Perform serial abdominal exams every 4-6 hours to detect development of peritonitis 1

• Worsening tenderness, new peritoneal signs, or rising lactate indicate need for urgent surgical intervention 1

When to Call Surgery Immediately

Surgical consultation is mandatory for:

• Any peritoneal signs (rebound, guarding, rigidity) 2, 1
• Elevated lactate or metabolic acidosis suggesting ischemia 1
• CT showing bowel obstruction with transition point, free air, or signs of ischemia 1
• Hemodynamic instability despite resuscitation 2, 1

For suspected mesenteric ischemia: immediate CT angiography and surgical consultation without delay 1