hypoglycaemia
Table of Contents
hypoglycaemia
see also:
introduction
- in diabetic patients, hypoglycaemia is usually defined as blood glucose concentration less than 3.5 mmol/L
clinical features of hypoglycaemia
- Recurrent hypoglycaemia or long-standing diabetes can cause a dulling or loss of warning symptoms. This is referred to as “hypoglycaemia unawareness”. In this case, the first sign of hypoglycaemia may be unconsciousness.
early symptoms
- sweating
- irritability
- palpitations
- trembling
- tingling of fingers and lips
- headache
later symptoms
- 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
adults with prolonged hypoglycaemic coma and resultant hypoglycaemic encephalopathy
- 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 1)
- early seizures appear to be a good prognostic sign (although in rat models they were correlated with increased mortality)4)
- 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 marker5)
- 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.
Mx of hypoglycaemia in diabetic patients
initial Mx if conscious and able to swallow
- 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
initial Mx if unable to swallow
- 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
recovery from hypoglycaemia
- 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
Do NOT with-hold insulin in patients with type I diabetes as this may result in diabetic ketoacidosis (DKA)
identify and manage cause of hypoglycaemia
- missed or delayed meal
- insufficient carbohydrate
- increased physical activity
- excessive medication
- renal impairment
- hypothyroidism
- adrenal insufficiency
hypoglycaemia.txt · Last modified: 2021/05/22 04:16 by gary1