Makindo Medical Notes

🧮 Calculated Osmolality = 2 × (Na⁺ + K⁺) + Urea + Glucose 💡 Frequently tested in exams — always calculate in suspected HHS! ⚠️ Key difference from DKA → minimal/absent ketones, no acidosis.

⚡ Initial Management Summary

🎯 Goals of Treatment

• 🌊 Normalise osmolality
• 💧⚡ Restore fluid & electrolyte balance
• 📉 Gradual glucose reduction (< 5 mmol/L/hr)
• 🧠 Protect brain → avoid rapid Na⁺/osmolality shifts
• 🛡 Prevent complications (thrombosis, seizures, cerebral oedema)

👩‍⚕️ Clinical Features

• Profound dehydration & hypotension 💧
• Altered mental status, ↓ GCS, coma possible 🧠
• Tachycardia 💓
• ❌ No Kussmaul breathing / fruity acetone breath (unlike DKA)

🔍 Differential Diagnosis

• Septic shock 🦠
• Diabetic ketoacidosis (DKA) 🍫
• Diabetes insipidus 🚰

🧪 Investigations

• Bloods: FBC, U&E, LFTs, CRP, glucose, lactate
• VBG (ABG if hypoxic)
• Cultures: blood & urine 🧫
• CXR for infection, ECG for MI

💧 Fluid Replacement (≈ 6 L over 18 hrs in a 70 kg adult)

• 1 L 0.9% NaCl over 1 hr
• 1 L 0.9% NaCl + KCl over 2 hrs × 2
• 1 L 0.9% NaCl + KCl over 4 hrs × 2
• 1 L 0.9% NaCl + KCl over 6 hrs
• ⚖️ Switch to 0.45% NaCl if osmolality not falling
• ⚠️ Modify for elderly, cardiac/renal disease, or low BMI
• 🔎 Mandatory cardiovascular reassessment at 12 hrs

💉 Insulin (0.05 U/kg/hr IV)

• Not required early — fluids alone usually lower glucose
• Start if:
  • Ketones > 1 mmol/L OR urine ketones > 2+
  • Glucose not falling despite fluids
• 💉 Fixed rate infusion: 50 U Actrapid in 50 ml 0.9% NaCl (1 U/ml)
• Continue basal insulin (e.g., Lantus, Levemir, Tresiba)

🍬 IV Dextrose

• Start 10% dextrose when CBG < 14 mmol/L
• Give alongside 0.9% saline (separate lines)
• 🎯 Target: glucose fall < 5 mmol/L/hr

📉 Monitoring

• Na⁺ drop < 10 mmol/L/day
• Glucose drop < 5 mmol/L/hr
• Close monitoring: GCS, BP, HR, fluid balance

🔎 Identify & Treat Precipitant

• 🦠 Infection → CXR, cultures, antibiotics
• ❤️ ECG → look for silent MI
• 💊 Review medications & adherence

📚 References

• JBDS Guidelines: HHS in Adults (2012)

💡 Exam Tip: 🔹 HHS = older, type 2, glucose >30, osmolality >320, severe dehydration, minimal ketones. 🔹 DKA = younger, type 1, ketonaemia + acidosis. Memorise this contrast for OSCEs & MCQs! 🧠