hypoglycaemia

see also:

• diabetes_mellitus
• hypoglycaemia in the non-diabetic patient
• neonatal hypoglycaemia
• RCH guideline - hypoglycaemia in children
• RCH: oral hypoglycemic poisoning in children
• Western Health P&P - Mx of hypoglycaemia in adult diabetics (doc - WH Intranet only)

• in diabetic patients, hypoglycaemia is usually defined as blood glucose concentration less than 3.5 mmol/L

• diabetic patients on hypoglycaemic agents
  • supplemental pyridoxine (vitamin B6) may increase risk ¹⁾
• other causes:
  • see hypoglycaemia in the non-diabetic patient

• sweating
• irritability
• palpitations
• trembling
• tingling of fingers and lips
• headache

• disturbance of concentration
• slurred speech
• aggressive behaviour
• confusion
• seizures
• loss of consciousness
• short periods of hypoglycaemia usually have a relatively full return to neurologic function

• prolonged periods with GCS < 8 may result in potentially permanent or life threatening hypoglycaemic encephalopathy:
  • mortality rate despite prolonged ICU care may be around 40% while over a third have “good outcomes” (including moderate disability but independent living) by 1 yr follow up ²⁾
  • greater than 8 hours of hypoglycaemia appears to be associated with a poor outcome and duration of hypoglycaemia (rather than other features such as blood glucose level, a low lactate or presence of hypothermia³⁾ ) appears to be a major determinant of outcome ⁴⁾
  • early seizures appear to be a good prognostic sign (although in rat models they were correlated with increased mortality)⁵⁾
  • variably induces early lesions of the internal capsule that may secondarily reach the white matter
  • CT scans if they show anything generally show bilateral changes in cortex, basal ganglia and white matter, while a normal CT can be seen as a good prognostic marker⁶⁾
  • EEG generally shows a slowed brain electrical activity
  • absence of lesions on the first early diffusion MRI was associated with good outcome
  • those with good pre-morbid health but who are not appearing to clinically improve, generally require a minimum of 10-15 days of ICU care before deciding upon treatment thresholds.

• give rapidly absorbed simple carbohydrate ASAP:
  • 1 tube glucose gel (15g), or,
  • a small glass (150mL) of Lucozade, strong cordial, fruit juice (apple or orange juice) or soft drink (NOT sugar free)
  • if symptoms not settling, repeat in 5-10min.
• follow with a long acting carbohydrate to maintain blood glucose level:
  • half a sandwich, or,
  • a piece of fruit, or,
  • a glass of milk, or,
  • 4-6 dry biscuits, or,
  • next meal if due

• place patient on their side
• ensure clear airway
• for adults, give 25-50mls 50% dextrose iv (can dilute to 25% or 12.5% to reduce venous irritation)
• if iv access not available or difficult, give 1mg glucagon im (for adults)
• ongoing 5% dextrose 100mL/hr infusion may be needed
• give slow acting carbohydrate as above when able to swallow

• clinical symptoms generally resolve within 5 minutes of iv or im Rx as above, but complete recovery of symptoms may take hours, particularly if hypoglycaemia was prolonged or severe
• watch for and Rx any recurrence of hypoglycaemia after initial Rx:
  • recheck BGL within 15-20min then if BGL > 3.9 re-commence qid checks
  • if patient had been unconscious, check dextrostix hourly for 4 hours
  • BGL may remain unstable for 24 hours
• ensure patient education

• missed or delayed meal
• insufficient carbohydrate
• increased physical activity
• excessive medication
• renal impairment
• hypothyroidism
• adrenal insufficiency