“I feel so dizzy when I stand…” — Mock Patient Script: Hypovolemia

Standard Case – Vomiting and Orthostatic Dizziness

1. Case Title

“I’ve been throwing up all day, and now I feel dizzy when I stand.”

2. Doorway Information

• Age / Gender: 24-year-old female
• Chief Complaint: Nausea, vomiting, and dizziness
• Vital Signs: T 37.2°C, HR 108, BP 88/56, RR 18, SpO₂ 98% (room air)

3. Structured History

Opening: “I’ve been vomiting since last night, and now I feel super dizzy when I stand up.”

Onset & Course: “It started about 12 hours ago after I ate sushi from a convenience store. I threw up twice during the night and again this morning. I’ve been lying down most of the time since then.”

Associated Symptoms: “My stomach felt kind of crampy, but no real pain. No diarrhea. I feel a bit cold and shaky. No fever that I noticed.”

Mood / Function / Appetite / Sleep: “I couldn’t eat anything today. Even water makes me nauseous. I slept poorly because I kept waking up to run to the bathroom.”

Medical History / Medication: “I’m usually healthy. I take birth control pills, that’s it. No allergies, no chronic conditions.”

PAM HITS FOSS:

• P: “I had food poisoning once before, but it wasn’t this bad.”
• A: “None.”
• M: “Just birth control pills.”
• H: “Never.”
• I: “None.”
• T: “No history of trauma.”
• S: “No surgeries.”
• F: “Mom has migraines. No major illnesses.”
• O: “No pregnancies, regular cycles.”
• S: “Monogamous with my boyfriend. No STIs.”
• S: “College student, no smoking, occasional alcohol.”

Concerns & Questions: “Is this just food poisoning? Will I need an IV or something?”

4. Physical Examination

• General: Appears tired, lying down, slightly dry lips
• HEENT: Mildly dry mucous membranes, no scleral icterus
• Neck: No lymphadenopathy
• Chest: Clear to auscultation bilaterally
• Cardiovascular: HR ↑, regular rhythm, no murmur
• Abdomen: Mild epigastric tenderness, no rebound, no guarding, normal bowel sounds
• Neuro: Alert and oriented ×3, no focal deficits
• Extremities: Delayed capillary refill (~3 sec), no edema
• Orthostatic vitals: Positive — drop in BP by 20 mmHg systolic with dizziness
• Skin: No rash, normal turgor but mildly decreased

5. Differential Diagnosis

1. Hypovolemia due to acute gastroenteritis / foodborne illness
   • Supporting points: Acute vomiting, poor oral intake, orthostatic hypotension, dry mucosa
   • Contradictory points: No fever or diarrhea
2. Viral gastritis
   • Supporting: Common in young adults, especially with mild GI symptoms
   • Contradictory: No fever, no known contacts
3. Pregnancy-related vomiting (early pregnancy / hyperemesis gravidarum)
   • Supporting: Young female, nausea and vomiting
   • Contradictory: On oral contraceptives, no missed periods

6. Clinical Reflection

“She looks mildly dehydrated but not in shock. The orthostatic changes are a big clue. This could just be simple food poisoning, but I should also rule out pregnancy and check electrolytes just in case.”

7. Clinical Tips

• 🚧 Vomiting + low BP + dry mouth = Hypovolemia until proven otherwise
• 🔽 Orthostatic vitals are your friend — don’t forget to check them
• 🧪 Young women with vomiting → always consider pregnancy test
• 💧 Mild hypovolemia often responds well to oral rehydration, but IV may be needed

8. Challenging Questions

Q: “Can I just go home and rest?”
A: “That may be possible, but I’m concerned that you’re showing signs of dehydration. Your blood pressure is low, and you’re getting dizzy when standing. Let’s rehydrate you and check a few labs first to be safe.”

Q: “Is it food poisoning? Or something worse?”
A: “It could very well be food poisoning, especially since symptoms started after sushi. But we’ll keep an open mind and run some basic tests to rule out other causes. We’ll also make sure you’re safe to go home.”

9. 📝 SOAP Note

S:
24-year-old previously healthy female presents with 12-hour history of vomiting and dizziness on standing. No diarrhea or fever. Poor oral intake. No abdominal pain. Denies pregnancy.

O:
T 37.2°C, HR 108, BP 88/56, RR 18, SpO₂ 98%
Orthostatic: systolic BP drop by >20 mmHg, dizziness
Dry mucosa, delayed capillary refill
Mild epigastric tenderness, no rebound/guarding

A:
# Vomiting with poor oral intake
# Orthostatic hypotension
# Clinical signs of mild hypovolemia

ddx): Foodborne illness, viral gastroenteritis, early pregnancy
r/o): Surgical abdomen (no peritonitis), UTI, CNS cause (no neuro deficits)
→ Likely volume depletion from acute gastroenteritis. Needs fluid replacement and monitoring.

P:
- IV fluids (normal saline bolus 1L, reassess)
- Electrolyte panel, BUN/Cr, CBC
- Urine β-hCG
- Antiemetics PRN
- Oral rehydration once tolerated
- Observe for improvement, consider discharge if stable

Challenging Case – Pancreatitis with Third Spacing

1. Case Title

“I thought it was just stomach flu, but now I’m too weak to get out of bed.”

2. Doorway Information

• Age / Gender: 56-year-old male
• Chief Complaint: Epigastric pain and weakness
• Vital Signs: T 37.5°C, HR 118, BP 86/54, RR 24, SpO₂ 95% (room air)

3. Structured History

Opening: “I just feel exhausted and my stomach’s been hurting for days.”

Onset & Course: “It started about two days ago. I had this dull pain in the upper belly that got worse and now goes to my back. I thought it was just a stomach bug, but I haven’t been able to eat or drink anything since yesterday.”

Associated Symptoms: “I feel nauseated but haven’t vomited much. My belly feels kind of tight and swollen. No fever, no diarrhea, but I’ve barely urinated since last night.”

Mood / Function / Appetite / Sleep: “I’m too tired to even stand up for long. Haven’t eaten in over 24 hours. I slept a little but kept waking up because of the pain.”

Medical History / Medication: “I’ve had high blood pressure for years. I sometimes drink a lot, especially on weekends. I’m not on any regular meds. No surgeries.”

PAM HITS FOSS:

• P: “Had mild belly pain a few times, but nothing like this.”
• A: “None that I know of.”
• M: “Not currently taking anything.”
• H: “None.”
• I: “No major injuries.”
• T: “No trauma history.”
• S: “Never had surgery.”
• F: “Dad had diabetes. Mom had high blood pressure.”
• O: N/A
• S: “Stable relationship. No recent exposures.”
• S: “Drinks alcohol regularly (5–6 drinks on weekends), smokes occasionally.”

Concerns & Questions: “Is this something serious? I didn’t think stomach problems could make me feel this weak.”

4. Physical Examination

• General: Appears ill and weak, lying supine, minimal movement
• HEENT: Dry mucous membranes, slightly sunken eyes
• Neck: Supple, no lymphadenopathy or JVD
• Chest: Clear to auscultation
• Cardiovascular: Tachycardic, no murmurs, weak peripheral pulses
• Abdomen: Distended, epigastric tenderness without guarding or rebound, reduced bowel sounds
• Neuro: Alert but fatigued, no focal deficits
• Skin: Dry, poor skin turgor, no rash
• Extremities: No edema, cool peripheries, delayed capillary refill

5. Differential Diagnosis

1. Pancreatitis with third spacing
   • Supporting points: Epigastric pain radiating to back, history of alcohol use, abdominal distension, signs of hypovolemia
   • Contradictory points: No vomiting or fever
2. Acute gastritis
   • Supporting: Nausea, epigastric discomfort
   • Contradictory: Severe hypotension and third spacing signs unlikely
3. GI obstruction
   • Supporting: Distended abdomen, nausea
   • Contradictory: No vomiting or high-pitched bowel sounds

6. Clinical Reflection

“This case is much more serious — signs of third spacing and volume depletion are clear. The patient may be developing pancreatitis-induced hypovolemia. I’ll need labs, imaging, and early fluid resuscitation.”

7. Challenging Questions

Q: “Can I just sleep this off?”
A: “I understand you’re feeling exhausted, but your blood pressure is very low, and you may be dehydrated from something more serious. We’ll need to give fluids and run tests right away.”

Q: “Do I need to be admitted?”
A: “At this point, yes. With your vital signs and how sick you look, we should keep you in the hospital for fluids and monitoring. We’ll find out what’s causing this and treat it quickly.”

8. 📝 SOAP Note

S:
56-year-old male with 2-day history of worsening epigastric pain radiating to the back. Weakness, poor intake, minimal urine output. No fever or vomiting. Alcohol use on weekends.

O:
T 37.5°C, HR 118, BP 86/54, RR 24, SpO₂ 95%
Dry mucous membranes, distended abdomen, epigastric tenderness, reduced bowel sounds, delayed capillary refill, weak pulses

A:
# Epigastric pain and dehydration
# Orthostatic hypotension and poor oral intake
# Suspected pancreatitis with third spacing

ddx): Pancreatitis, GI obstruction, acute gastritis
r/o): Cardiac cause (no chest pain), sepsis (no fever or infection signs)
→ Likely hypovolemia due to third spacing from pancreatitis. Needs fluid resuscitation and confirmatory labs/imaging.

P:
- IV fluids (aggressive hydration with lactated Ringer’s)
- Labs: CBC, CMP, lipase, amylase, LFTs, ABG
- Abdominal ultrasound or CT
- NPO, antiemetics, pain control
- Admit to hospital for monitoring and further workup

References

• UpToDate: Evaluation of hypovolemia in adults
• Tintinalli’s Emergency Medicine
• First Aid for the USMLE Step 2 CS

Recommended Resources

• 書籍: 『レジデントの鉄則』、『ティアニー先生の臨床推論』
• 教材: First Aid Step 2 CS, Snap Diagnosisを鍛える99症例
• Note記事: 「英語で学ぶ症候別診断」シリーズ