# Clinical Cases: Diabetes Management

## Case 1: Diabetic Ketoacidosis

### Patient Presentation
A 28-year-old woman with type 1 diabetes mellitus presents with nausea, vomiting, and abdominal pain for 2 days. She reports increased thirst and urinary frequency over the past week. She admits to running out of her insulin 3 days ago and being unable to afford a refill. She denies fever, dysuria, or respiratory symptoms.

### Vital Signs
- Blood Pressure: 98/62 mmHg
- Heart Rate: 118 bpm
- Respiratory Rate: 28/min (Kussmaul respirations)
- Oxygen Saturation: 99% on room air
- Temperature: 37.2°C

### Physical Examination
- General: Ill-appearing, drowsy but arousable, fruity breath odor
- HEENT: Dry mucous membranes, sunken eyes
- Cardiovascular: Tachycardic, regular rhythm
- Pulmonary: Deep, rapid respirations; lungs clear
- Abdomen: Diffusely tender without rebound or guarding
- Skin: Decreased turgor, no rashes
- Neurologic: Alert and oriented, no focal deficits

### Initial Workup
- **Glucose**: 485 mg/dL
- **Sodium**: 128 mEq/L
- **Potassium**: 5.8 mEq/L
- **Chloride**: 95 mEq/L
- **Bicarbonate**: 8 mEq/L
- **BUN/Creatinine**: 32/1.8 mg/dL
- **Anion gap**: 25 mEq/L
- **Arterial pH**: 7.18
- **Serum ketones**: Large
- **Urinalysis**: Glucose 4+, ketones 3+, no leukocytes

### Clinical Image
![Kussmaul Respirations](image_01.png)
*Figure 1: Diagram illustrating Kussmaul respirations - deep, labored breathing pattern representing respiratory compensation for metabolic acidosis in diabetic ketoacidosis.*

**Image Source**: Educational illustration for teaching purposes.

### Questions

1. **What are the diagnostic criteria for diabetic ketoacidosis (DKA)?**
   - A) Glucose >200, pH <7.35, bicarbonate <18, ketones positive
   - B) Glucose >250, pH <7.30, bicarbonate <18, ketones positive, anion gap >12
   - C) Glucose >400, pH <7.20, bicarbonate <15, ketones positive
   - D) Glucose >300, pH <7.25, bicarbonate <20, anion gap >10

2. **What is the corrected sodium in this patient?**
   - A) 128 mEq/L
   - B) 132 mEq/L
   - C) 134 mEq/L
   - D) 136 mEq/L

3. **What is the most critical electrolyte to monitor during DKA treatment?**
   - A) Sodium
   - B) Potassium
   - C) Calcium
   - D) Phosphorus

4. **Outline the initial management priorities in treating DKA.**

5. **When should sodium bicarbonate be administered in DKA?**

### Answers

1. **B) Glucose >250, pH <7.30, bicarbonate <18, ketones positive, anion gap >12** - DKA is characterized by hyperglycemia (>250 mg/dL), metabolic acidosis (pH <7.30, bicarbonate <18), positive serum/urine ketones, and elevated anion gap (>12).

2. **C) 134 mEq/L** - Corrected sodium = measured sodium + 1.6 × [(glucose - 100)/100]. Here: 128 + 1.6 × [(485-100)/100] = 128 + 6.16 ≈ 134 mEq/L. This corrects for dilutional hyponatremia from hyperglycemia.

3. **B) Potassium** - Although serum potassium may be normal or elevated on presentation, total body potassium is depleted. Insulin administration drives potassium intracellularly, risking severe hypokalemia. Do not start insulin until K+ >3.3 mEq/L.

4. **Initial management priorities**:
   - **Fluids**: Normal saline 1-1.5 L/hour initially; switch to 0.45% saline when sodium normalizes
   - **Insulin**: Regular insulin 0.1 units/kg bolus, then 0.1 units/kg/hour infusion (after confirming K+ >3.3)
   - **Potassium**: Add 20-40 mEq/L to fluids when K+ <5.3 mEq/L
   - **Monitor**: Glucose hourly, electrolytes every 2-4 hours
   - **Dextrose**: Add D5 to fluids when glucose <200-250 mg/dL
   - **Search for precipitant**: Infection, medication non-adherence, MI, etc.

5. **Bicarbonate administration**:
   - Only indicated when pH <6.9
   - 100 mEq sodium bicarbonate in 400 mL sterile water with 20 mEq KCl over 2 hours
   - Routine bicarbonate administration is not recommended for pH ≥6.9
   - May cause paradoxical CNS acidosis and hypokalemia

---

## Case 2: Type 2 Diabetes - Initiating and Intensifying Therapy

### Patient Presentation
A 52-year-old man with type 2 diabetes diagnosed 5 years ago presents for routine follow-up. He is currently on metformin 1000 mg twice daily. He reports good medication adherence but has gained 15 pounds over the past year. He has a history of hypertension and hyperlipidemia. He denies polyuria, polydipsia, or visual changes.

### Vital Signs
- Blood Pressure: 142/88 mmHg
- Heart Rate: 76 bpm
- BMI: 34 kg/m²
- Weight: 104 kg

### Physical Examination
- General: Obese, well-appearing
- Cardiovascular: Regular rhythm, no murmurs
- Pulmonary: Clear
- Abdomen: Obese, non-tender
- Extremities: No edema, intact sensation to monofilament
- Skin: Acanthosis nigricans on neck

### Laboratory Results
- **HbA1c**: 8.4% (goal <7%)
- **Fasting glucose**: 168 mg/dL
- **Creatinine**: 0.9 mg/dL, eGFR 95 mL/min
- **Urine albumin/creatinine ratio**: 45 mg/g (mildly elevated)
- **Lipid panel**: LDL 118 mg/dL, HDL 38 mg/dL, TG 210 mg/dL

### Clinical Image
![Acanthosis Nigricans](image_02.png)
*Figure 2: Acanthosis nigricans - velvety, hyperpigmented skin changes at the posterior neck, associated with insulin resistance and type 2 diabetes.*

**Image Source**: Educational illustration for teaching purposes.

### Questions

1. **According to current guidelines, what is the most appropriate medication to add for this patient with established cardiovascular risk factors?**
   - A) Sulfonylurea (glipizide)
   - B) SGLT2 inhibitor (empagliflozin)
   - C) DPP-4 inhibitor (sitagliptin)
   - D) Thiazolidinedione (pioglitazone)

2. **What are the cardiovascular and renal benefits of SGLT2 inhibitors?**
   - A) Improved glycemic control only
   - B) Reduced risk of heart failure hospitalization and CKD progression
   - C) Lower LDL cholesterol
   - D) Reduced risk of stroke only

3. **Which medication class would be most beneficial for weight loss in this patient?**
   - A) Sulfonylureas
   - B) Insulin
   - C) GLP-1 receptor agonists
   - D) Thiazolidinediones

4. **What is the significance of the elevated urine albumin/creatinine ratio?**

5. **What blood pressure goal should be targeted for this diabetic patient?**

### Answers

1. **B) SGLT2 inhibitor (empagliflozin)** - For patients with type 2 diabetes and established cardiovascular disease, heart failure, or CKD, SGLT2 inhibitors are recommended as add-on therapy to metformin regardless of HbA1c due to proven cardiovascular and renal benefits.

2. **B) Reduced risk of heart failure hospitalization and CKD progression** - SGLT2 inhibitors have demonstrated reductions in heart failure hospitalization (EMPA-REG, CANVAS, DECLARE trials) and slowed progression of diabetic kidney disease independent of glucose-lowering effects.

3. **C) GLP-1 receptor agonists** - GLP-1 RAs (semaglutide, liraglutide) cause significant weight loss (average 5-15% body weight). Sulfonylureas and insulin cause weight gain; TZDs cause fluid retention and weight gain.

4. **Elevated urine albumin/creatinine ratio significance**:
   - Indicates early diabetic nephropathy (moderately increased albuminuria: 30-300 mg/g)
   - Strong predictor of progressive kidney disease and cardiovascular events
   - Indication for ACE inhibitor or ARB therapy
   - Supports use of SGLT2 inhibitor for renal protection
   - Should prompt more aggressive glycemic and blood pressure control

5. **Blood pressure goal**: <130/80 mmHg for diabetic patients according to ADA guidelines. Tighter control is especially important in those with albuminuria. This patient should be started on an ACE inhibitor or ARB given his hypertension and albuminuria.

---

## Case 3: Hyperosmolar Hyperglycemic State

### Patient Presentation
A 68-year-old man with type 2 diabetes is brought to the emergency department by his daughter who found him confused and difficult to arouse. She reports he has had decreased oral intake due to a "stomach bug" for the past week and has been less responsive over the past 2 days. His medications include metformin and glipizide, which he has not been taking due to nausea.

### Vital Signs
- Blood Pressure: 92/58 mmHg
- Heart Rate: 108 bpm
- Respiratory Rate: 18/min
- Oxygen Saturation: 96% on room air
- Temperature: 37.8°C

### Physical Examination
- General: Obtunded, arousable to painful stimuli only
- HEENT: Extremely dry mucous membranes
- Cardiovascular: Tachycardic, weak pulses
- Pulmonary: Clear
- Abdomen: Non-tender
- Skin: Tenting, no rashes
- Neurologic: GCS 10 (E2V3M5), no focal deficits

### Initial Workup
- **Glucose**: 1,150 mg/dL
- **Sodium**: 152 mEq/L
- **Potassium**: 4.2 mEq/L
- **Bicarbonate**: 22 mEq/L
- **BUN/Creatinine**: 68/3.2 mg/dL
- **Serum osmolality**: 385 mOsm/kg (calculated: 378)
- **Arterial pH**: 7.32
- **Serum ketones**: Trace

### Clinical Image
![HHS vs DKA Comparison](image_03.png)
*Figure 3: Comparison table of diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) highlighting key differentiating features.*

**Image Source**: Educational illustration for teaching purposes.

### Questions

1. **What are the diagnostic criteria for hyperosmolar hyperglycemic state (HHS)?**
   - A) Glucose >400, osmolality >300, pH >7.30, minimal ketones
   - B) Glucose >600, osmolality >320, pH >7.30, minimal ketones
   - C) Glucose >500, osmolality >310, pH <7.30, positive ketones
   - D) Glucose >800, osmolality >350, pH >7.25, no ketones

2. **What is the estimated fluid deficit in HHS?**
   - A) 2-3 liters
   - B) 4-6 liters
   - C) 8-12 liters
   - D) 1-2 liters

3. **What is the most important difference in management between HHS and DKA?**
   - A) Insulin dose is higher in HHS
   - B) Bicarbonate is always needed in HHS
   - C) Fluid resuscitation is more critical in HHS
   - D) Potassium replacement is not needed in HHS

4. **What is the significance of the neurologic findings in HHS?**

5. **What precipitating factors should be investigated?**

### Answers

1. **B) Glucose >600, osmolality >320, pH >7.30, minimal ketones** - HHS is characterized by severe hyperglycemia (>600 mg/dL), hyperosmolality (>320 mOsm/kg), minimal or no ketosis, and absence of significant acidosis (pH >7.30).

2. **C) 8-12 liters** - Patients with HHS typically have profound volume depletion (8-12 L deficit) due to osmotic diuresis occurring over days to weeks. This is greater than the typical 5-7 L deficit in DKA.

3. **C) Fluid resuscitation is more critical in HHS** - While both require aggressive fluid replacement, HHS requires even more emphasis on volume repletion. Glucose often drops significantly with fluids alone, and insulin requirements may be lower than in DKA.

4. **Neurologic findings significance**:
   - Mental status changes (confusion, lethargy, coma) are more common in HHS than DKA
   - Correlate with degree of hyperosmolality (typically >320-330 mOsm/kg causes obtundation)
   - Focal neurologic deficits may occur and mimic stroke
   - Usually reversible with treatment
   - Rate of correction should avoid cerebral edema (gradual reduction in osmolality)

5. **Precipitating factors to investigate**:
   - Infection (most common): pneumonia, UTI, sepsis
   - Medication non-adherence
   - New diagnosis of diabetes
   - Myocardial infarction or stroke
   - Medications: steroids, thiazides, antipsychotics
   - Gastrointestinal illness with dehydration
   - This patient likely had viral gastroenteritis leading to dehydration and medication non-adherence

---

## Learning Points

1. **DKA** is characterized by hyperglycemia, ketosis, and metabolic acidosis; treatment priorities are fluids, insulin, potassium replacement, and identification of precipitant.

2. **HHS** features severe hyperglycemia and hyperosmolality without significant ketosis; fluid resuscitation is paramount.

3. **Potassium monitoring** is critical in both conditions as total body potassium is depleted despite normal or elevated serum levels.

4. **Diabetes management** should be individualized based on cardiovascular and renal comorbidities; SGLT2 inhibitors and GLP-1 agonists offer benefits beyond glucose control.

5. **HbA1c goal** of <7% is appropriate for most patients; less stringent goals may be appropriate for those with limited life expectancy or high hypoglycemia risk.