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📞 Phone Triage in Type 2 DM with Lethargy: Could it Be DKA, HHS, MALA, or Silent MI? PLAB 2

Updated: Oct 19



When a patient with Type 2 Diabetes on metformin only calls and says they're “very tired,” don’t dismiss it. Lethargy could signal a life-threatening complication such as:

  • Metformin-Associated Lactic Acidosis (MALA)

  • Hyperosmolar Hyperglycemic State (HHS)

  • Silent Myocardial Infarction (MI)

  • Diabetic Ketoacidosis (DKA) (rare in T2DM but still possible)


🚨 Common Theme: These Are All Medical Emergencies

And the faster we identify them — even over the phone — the better the outcome.


⚠️ Step 1: Risk Factors That May Precipitate Each Condition

Condition

Risk Factors

MALA (Metformin-Associated Lactic Acidosis)

🔹 Acute kidney injury (e.g., dehydration, NSAIDs)


 🔹 Sepsis or recent infections


 🔹 Liver disease or alcohol use


 🔹 Surgery or hypoxia


 🔹 Recent contrast imaging (CT/MRI with dye)

HHS (Hyperosmolar Hyperglycemic State)

🔹 Missed medications


 🔹 Infections (UTI, pneumonia)


 🔹 Stroke, MI, trauma


 🔹 Diuretic or steroid use


 🔹 Long-standing uncontrolled T2DM

Silent MI

🔹 Diabetes (autonomic neuropathy)


 🔹 Hypertension, dyslipidemia


 🔹 Smoking history


 🔹 Older age


 🔹 Family history of IHD

DKA (usually occurs in T1DM)

🔹 Severe infections


 🔹 Starvation or vomiting


 🔹 Undiagnosed T1DM


 🔹 SGLT2 inhibitor use


 🔹 Major surgery or trauma

Risk Factors:

  • MALA: AKI, sepsis, liver disease, alcohol, contrast scans, hypoxia

  • HHS: Missed meds, infections, steroids, long-standing uncontrolled T2DM

  • Silent MI: Autonomic neuropathy, hypertension, dyslipidemia, family history

  • DKA: Vomiting, starvation, SGLT2i use, major illness/surgery


🧠 Other drugs to ask about:

  • ACE inhibitors / ARBs → worsen renal perfusion

  • Diuretics → contribute to dehydration

  • Metformin → safe unless renal function is impaired

  • Contrast agents → may trigger AKI and MALA


Ask the patient:

  • “Have you taken any painkillers like ibuprofen or diclofenac?”

  • “Any recent scans with dye, or medicines for blood pressure or fluid retention?”

✅ If NSAID use is suspected:“NSAIDs can reduce kidney function, especially if you're dehydrated or unwell. This can worsen how your diabetes medications affect your body. We need to check this urgently.”

📋 Step 2: Structured Telephone Questions to Ask

🔍 A. Symptom Exploration

  • When did the tiredness start? Is it worsening?

  • Any vomiting, diarrhea, or chest pain?

  • Any deep or fast breathing?

  • Have you urinated today? Is it less than usual?

  • Are you feeling drowsy, confused, or faint?

  • Any fever or signs of infection recently?

💊 B. Medication & Medical History

  • Are you still taking metformin?

  • Are you on SGLT2 inhibitors (like empagliflozin)?

  • Any known kidney, liver, or heart issues?

  • Any recent hospital visits, contrast scans, or missed meals?


🧠 Step 3: Understand the Likely Diagnosis Based on Clues

Condition

Breathing

Vomiting

Mental State

Chest Pain

Others


MALA

Deep, rapid

Yes

Confusion, lethargy

Rare

Unwell and increased glucose


HHS

Sometimes deep

Sometimes

Drowsy, very lethargic

Possible

Altered Mental Status. Polyuria/Polydipsia


Silent MI

New or worsening shortness of breath.

Rare

Weakness, vague malaise

Mild or no pain

Nausea or Indigestion, Cold, clammy


DKA

Kussmaul breathing

Yes

Drowsy/confused

Rare

Lethargy, confusion, abdominal pain


🎯 Note: DKA is less likely in metformin-only patients, but possible in severe illness, or SGLT2i users.

📞 Step 4: What to Say to the Patient

A. Urgent Advice

“I’m concerned your symptoms could indicate a serious medical condition related to your diabetes or heart. Please go to the emergency department immediately — or I can help arrange an ambulance for you.”

B. Clear Instructions

  • Stop metformin for now.

  • Avoid eating or drinking until reviewed.

  • Lie down flat or in recovery position if vomiting.

  • Ensure someone stays with them.

🏥 Step 5: What Will Be Done at Hospital

Condition

Tests

Treatment

MALA

ABG, lactate, renal function

IV fluids, bicarbonate, dialysis if severe

HHS

Glucose, osmolality, U&Es

IV fluids, low-dose insulin, potassium

Silent MI

ECG, troponins, BP

Antiplatelets, oxygen, ECG monitoring

DKA

Glucose, ketones, pH

IV insulin, fluids, electrolyte correction

📌 Summary: Triage Pearls

  • 🟠 MALA → Look for vomiting, acidosis, confusion in a metformin user

  • 🔵 HHS → Profound dehydration and altered sensorium in T2DM

  • 🔴 Silent MI → Always consider in diabetics with unexplained fatigue

  • ⚠️ DKA → Still possible in atypical T2DM (e.g., SGLT2i use)

  • ❗ NSAIDs and nephrotoxic drugs can precipitate all of the above — always ask about recent use

📞 Over the phone, don’t waste time differentiating too much — they all require urgent hospital care.


🧠 OSCE/Exam Tip:

If you suspect any of these on a phone consultation:

  • Escalate confidently:

“I’m worried about a potentially serious complication. Please seek urgent care immediately.”

  • Safety-net clearly:

“Don’t take any further medication or food. Stay lying down and make sure someone is with you until help arrives.”

🧠 Other Differential Diagnoses for Lethargy in a Patient with Type 2 Diabetes on Metformin


⚠️ Medical Emergencies to Rule Out First:

  • ✅ MALA – Metformin + infection, dehydration, or renal impairment

  • ✅ DKA – Often in insulin-dependent or SGLT2i users, especially with vomiting

  • ✅ Silent MI – Common in diabetics with autonomic neuropathy



🩺 Other Important but Less Urgent Possibilities:


🩸 1. Hypoglycemia

  • Especially if the patient is on sulfonylureas or insulin

  • Symptoms: Sweating, confusion, irritability, shakiness

  • Check: “Have you eaten today?” “Did you take your medication before food?”


🧠 2. Electrolyte Imbalance

  • Causes: Dehydration, diuretics, vomiting, kidney disease

  • May cause: Muscle weakness, fatigue, altered mental state


🦠 3. Infection (e.g., UTI, pneumonia)

  • Often subtle in diabetics

  • Ask: “Any fever, cough, pain on urination, abdominal discomfort?”


🌡️ 4. Hypothyroidism

  • Fatigue, weight gain, cold intolerance, dry skin

  • Can be slowly progressive

  • Consider if symptoms are chronic


🧬 5. Anemia

  • Especially in those with chronic kidney disease or GI bleeding

  • Ask about: Pallor, dizziness, heavy periods (in women), black stools


💊 6. Medication Side Effects

  • Not just metformin — beta-blockers, antihistamines, sedatives, etc.

  • Review recent medication changes


🧠 7. Depression or Mental Health Issues

  • Common in chronic illness

  • Ask gently: “How have you been feeling emotionally?” or “Any trouble sleeping or enjoying things?”


🧽 8. Chronic Kidney Disease (CKD) Progression

  • Common in diabetics

  • Early signs: Fatigue, nausea, poor appetite, swelling

  • Metformin accumulation can worsen fatigue if GFR is low


🔋 9. Poor Sleep / Obstructive Sleep Apnea

  • Very common in overweight diabetics

  • Clues: Daytime sleepiness, loud snoring, morning headaches


📚 References

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