🩸 Chapter 91: Hypoglycaemia and Hyperglycaemia

Hypoglycaemia definition (<50 mg/dL) · Counter-regulatory hormones · Ketotic hypoglycaemia · Hyperinsulinism · Critical sample · Hyperglycaemia in ICU (stress) · Insulin therapy thresholds · Neonatal vs childhood causes

🔍 Core Concepts: Hypoglycaemia & Hyperglycaemia

📌 Definition
Hypoglycaemia: Blood glucose <50 mg/dL (neonates and children). Hyperglycaemia: stress-induced common in ICU; treat if persistent >150-180 mg/dL.
🩸 Counter-regulation
Glucagon, epinephrine, cortisol, growth hormone. Hyperinsulinaemia → hypofattyacidaemia, hypoketonaemia, inappropriate glycaemic response to glucagon (>40 mg/dL rise).
🍼 Ketotic Hypoglycaemia
Common in 18m-5y. Preceded by ketonuria. Alanine deficiency. Prevention: frequent high-protein/carbohydrate feeds.
📊 Critical Sample (during hypoglycaemia)
Glucose, insulin, FFA, ketones, lactate, cortisol, GH, ammonia, uric acid. Hyperinsulinaemia: insulin >2 µU/mL with low FFA and ketones.
💉 Management (Hypoglycaemia)
IV 10% dextrose 2 mL/kg bolus (seizure: 4 mL/kg). Follow with infusion 6-8 mg/kg/min. Treat underlying cause.
⚠️ Hyperglycaemia in ICU
Stress response (catecholamines, cytokines). Avoid dextrose-containing fluids for resuscitation. Insulin infusion if persistent >150-180 mg/dL.

🩺 Stepwise Approach: Hypoglycaemia

1
Recognise & confirm hypoglycaemia
Bedside glucose <50 mg/dL. Symptoms: autonomic (tachycardia, sweating, tremors) or neuroglycopenic (lethargy, seizures, coma).
2
Immediate treatment (IV access)
Give 10% dextrose 2 mL/kg IV (4 mL/kg if seizures). Follow with continuous infusion at 6-8 mg/kg/min. Recheck glucose in 15 min.
3
Draw critical sample (if possible before glucose)
Glucose, insulin, FFA, ketones, lactate, cortisol, GH, ammonia, uric acid, C-peptide. Urine for ketones.
4
Identify aetiology (based on critical sample)
Insulin >2 µU/mL + low FFA + low ketones → hyperinsulinism. High ketones + low alanine → ketotic hypoglycaemia. Low cortisol/GH → hormone deficiency.
5
Specific therapies
Hyperinsulinism: diazoxide, octreotide. Ketotic hypoglycaemia: frequent feeds, cornstarch. Hormone deficiency: replacement.
6
Prevention & monitoring
Maintain glucose >70 mg/dL. Avoid prolonged fasting. Educate family on ketone testing.