Hypoglycemia - Hyperexcision

Last updated: March 18, 2026Bookmark

Hypoglycaemia occurs when glucose concentration falls below 3.3 mmol/L. The threshold for the onset of hypoglycemic symptoms varies with patients. Severe symptomatic hypoglycemia occurs in most adults at blood glucose levels ≤ 2.2-2.8 mmol/L.

Hypoglycemia in patients with diabetes is defined as a blood glucose level ≤ 3.9 mmol/L.

Whipple triad – Helps to confirm the diagnosis of hypoglycemia

Low blood glucose levels (patients with diabetes have symptoms of hypoglycemia at higher thresholds than healthy individuals)
Signs or symptoms consistent with hypoglycemia
Relief of symptoms when blood glucose increases after treatment
Precipitating factors
- Insulin related
  - Insulin excess – overdose or wrongly timed medication
  - Liver or renal disease – decreased clearance of insulin
  - Weight loss – increased sensitivity to insulin
  - Increased exercise – increased sensitivity to insulin
  - Drug interactions
- Glucose related
  - Irregular ingestion of food
  - Alcohol ingestion
  - Extreme activity – increased utilization of glucose
  - Prior episodes of hypoglycemia leading to impaired awareness of hypoglycemia
  - Hypopituitarism and adrenal insufficiency
- Acute illness
  - Sepsis
  - Trauma
  - Burns
  - Organ failure
Pathophysiology
- Hypoglycaemia → activation of the sympathetic nervous system → autonomic symptoms
- Hypoglycaemia → brain dysfunction → neuroglycopaenic symptoms
- Recurrent episodes of hypoglycaemia → reduced epinephrine release, which lowers the threshold needed to trigger symptoms → Hypoglycemia-associated autonomic failure (HAAF) → asymptomatic hypoglycaemia
- Beta-blockers can mask signs of hypoglycemia by antagonizing the effects of epinephrine
Signs and symptoms
- Autonomic symptoms
  - Tremor
  - Pallor
  - Anxiety
  - Tachycardia
  - Sweating
  - Palpitations
  - Hunger
  - Paresthesia
  - Nausea
  - Vomiting
- Neuroglycopenic symptoms
  - Agitation
  - Confusion
  - Behavioral changes
  - Fatigue
  - Seizure
  - Focal Neurologic signs
  - Somnolence → Obtundation → Stupor → Coma → Death
Differentials
- Stroke or transient ischaemic attack
- Myocardial infarction
- Sepsis
- Epilepsy
- Idiopathic postprandial syndrome (pseudohypoglycaemia)
Investigations
- Random blood glucose
  - < 3.3 mmol/L
- Serum insulin
  - Elevated in insulinoma
- Serum C-peptide
  - Elevated in insulinoma and sulfonylurea use
- Serum cortisol
  - Reduced in adrenal insufficiency or hypopituitarism
- Toxicology screen for illicit drug use
- TSH for hypothyroidism
- LFTs for chronic liver disease or liver failure
- Blood alcohol for alcohol-induced hypoglycemia
- U&E for chronic kidney disease
Treatment
- Reverse hypoglycemia and expect prompt recovery
  - 15-20g of quick-acting carbohydrate snack (200ml orange juice or sweets) for patients who can swallow
  - GlucoGel or Dextrogel between the teeth and gums in uncooperative patients
  - IV Dextrose 10% at 200mL/h or IV Dextrose 10% 200mL/15min if unconscious or not responding to treatment
  - Fast-acting carbohydrates cannot be used to treat hypoglycemia caused by alpha-glucosidase inhibitors
  - Glucagon will not work in malnourished patients since glycogen reserves have been depleted
- Repeat snacks up to 3 times
- Recheck Blood glucose q10-15min
- Once blood glucose is >4.0 mmol/L, give long-acting carbohydrates such as bread
- Diazoxide can be used in some patients with chronic hypoglycaemia from excess endogenous insulin secretion
- Treat the underlying cause
Complications
- Coma
- Seizures
- Permanent neurologic deficits
  - Hemiparesis
  - Memory impairment
  - Diminished language skills
  - Decreased abstract thinking capabilities
  - Ataxia
- Arrhythmia
- Death
- Hypoglycaemia unawareness is more common in type 2 diabetes. This increases the risk of neuroglycopenic complications of hypoglycemia.

Hyperinsulinism due to Exogenous insulin vs Sulfonylureas

	Exogenous insulin	Sulfonylurea
Plasma insulin	Very high	High
C-peptide	Normal or low	High
Pro-insulin	Normal or low	Normal
Urine sulfonylurea	None	Present

Reference Intervals ›

Biochemistry

ACTH	P: <80 ng/L
ALT	P: 5–35 U/L
Albumin	P: 35–50 g/L
Aldosterone	P: 100–500 pmol/L
Alk. phosphatase	P: 30–130 U/L
α-Amylase	P: 0–180 IU/dL
α-Fetoprotein	S: <10 kU/L
Angiotensin II	P: 5–35 pmol/L
ADH	P: 0.9–4.6 pmol/L
AST	P: 5–35 U/L
Bicarbonate	P: 24–30 mmol/L
Bilirubin	P: 3–17 μmol/L
BNP	P: <50 ng/L
CRP	P: <10 mg/L
Calcitonin	P: <0.1 mcg/L
Calcium (ionized)	P: 1.0–1.25 mmol/L
Calcium (total)	P: 2.12–2.60 mmol/L
Chloride	P: 95–105 mmol/L
Cholesterol	P: <5.0 mmol/L
VLDL	P: 0.128–0.645 mmol/L
LDL	P: <2.0 mmol/L
HDL	P: 0.9–1.93 mmol/L
Cortisol AM	P: 450–700 nmol/L
Cortisol Midnight	P: 80–280 nmol/L
CK ♂	P: 25–195 U/L
CK ♀	P: 25–170 U/L
Creatinine	P: 70–100 μmol/L
Ferritin	P: 12–200 mcg/L
Folate	S: 2.1 mcg/L
FSH	P: 2–8 U/L ♂; >25 menopause
GGT ♂	P: 11–51 U/L
GGT ♀	P: 7–33 U/L
Glucose (fasting)	P: 3.5–5.5 mmol/L
Growth hormone	P: <20 mu/L
HbA1C (DCCT)	B: 4–6%
HbA1C (IFCC)	B: 20–42 mmol/mol
Iron ♂	S: 14–31 μmol/L
Iron ♀	S: 11–30 μmol/L
Lactate (venous)	P: 0.6–2.4 mmol/L
Lactate (arterial)	P: 0.6–1.8 mmol/L
LDH	P: 70–250 U/L
LH	P: 3–16 U/L
Magnesium	P: 0.75–1.05 mmol/L
Osmolality	P: 278–305 mosmol/kg
PTH	P: 0.8–8.5 pmol/L
Potassium	P: 3.5–5.3 mmol/L
Prolactin ♂	P: <450 U/L
Prolactin ♀	P: <600 U/L
PSA	P: 0–4 mcg/mL
Protein (total)	P: 60–80 g/L
Red cell folate	B: 0.36–1.44 μmol/L
Renin (erect)	P: 2.8–4.5 pmol/mL/h
Renin (recumbent)	P: 1.1–2.7 pmol/mL/h
Sodium	P: 135–145 mmol/L
TBG	P: 7–17 mg/L
TSH	P: 0.5–4.2 mU/L
T4	P: 70–140 nmol/L
Free T4	P: 9–22 pmol/L
TIBC	S: 54–75 μmol/L
Triglycerides	P: 0.50–2.3 mmol/L
T3	P: 1.2–3.0 nmol/L
Troponin T	P: <0.1 mcg/L
Urate ♂	P: 210–480 μmol/L
Urate ♀	P: 150–390 μmol/L
Urea	P: 2.5–6.7 mmol/L
Vitamin B12	S: 0.13–0.68 nmol/L
Vitamin D	S: 50 nmol/L

Arterial Blood Gases

pH	7.35–7.45
PaCO₂	4.7–6.0 kPa
PaO₂	>10.6 kPa
Base excess	±2 mmol/L

Urine

Cortisol (free)	<280 nmol/24h
Hydroxyindole acetic acid	16–73 μmol/24h
Hydroxymethylmandelic acid	16–48 μmol/24h
Metanephrines	0.03–0.69 μmol/mmol cr.
Osmolality	350–1000 mosmol/kg
17-Oxogenic steroids ♂	28–30 μmol/24h
17-Oxogenic steroids ♀	21–66 μmol/24h
17-Oxosteroids ♂	17–76 μmol/24h
17-Oxosteroids ♀	14–59 μmol/24h
Phosphate (inorganic)	15–50 mmol/24h
Potassium	14–120 mmol/24h
Protein	<150 mg/24h
Protein/creatinine ratio	<3 mg/mmol
Sodium	100–250 mmol/24h

Haematology

WCC	4.0–11.0 ×10⁹/L
RBC ♂	4.5–6.5 ×10¹²/L
RBC ♀	3.9–5.6 ×10¹²/L
Hb ♂	130–180 g/L
Hb ♀	115–160 g/L
PCV ♂	0.4–0.54 L/L
PCV ♀	0.37–0.47 L/L
MCV	76–96 fL
MCH	27–32 pg
MCHC	300–360 g/L
RDW	11.6–14.6%
Neutrophils	2.0–7.5 ×10⁹/L (40–75%)
Lymphocytes	1.0–4.5 ×10⁹/L (20–45%)
Eosinophils	0.04–0.44 ×10⁹/L (1–6%)
Basophils	0–0.10 ×10⁹/L (0–1%)
Monocytes	0.2–0.8 ×10⁹/L (2–10%)
Platelets	150–400 ×10⁹/L
Reticulocytes	0.8–2.0% / 25–100 ×10⁹/L
Prothrombin time	10–14 s
APTT	35–45 s

Paediatric

Pulse Rate (bpm)
Neonate	140–160
Infant <1yr	120–140
1–5 years	110–130
5–12 years	80–120
>12 years	70–100
Respiratory Rate (tachypnoea)
0–2 months	≥60/min
2–12 months	≥50/min
1–5 years	≥40/min
>5 years	≥30/min
Blood Pressure (mmHg)
Term	65/45
1 year	75/50
4 years	85/60
8 years	95/65
10 years	100/70
Weight Formulas
3–12 months	(a + 9)/2 kg
1–6 years	2a + 8 kg
>6 years	(7a − 5)/2 kg
Haemoglobin (g/dL)
Term newborn	13–20
1 month	11–18
2 months	10–15
1–2 years	10–13
>2 years	11–14
MUAC (6 months–5 years)
Obese	>17.5 cm
Normal	13.5–17.4 cm
At risk	12.5–13.4 cm
Moderate malnutrition	11.5–12.4 cm
Severe malnutrition	<11.5 cm
Developmental Milestones
Social smile	1.5 months
Head control	4 months
Sits unsupported	7 months
Crawls	10 months
Stands unsupported	10–12 months
Walks	12–13 months
Talks	18 months
CSF WBC (/mm³)
Term newborn	0–25
>2 weeks	0–5

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