hypoglycaemia Flashcards
(37 cards)
how would you manage acute hypoglycaemia in an alert and orientated patient ?
- Oral Carbohydrates:
- Rapid acting; juice / sweets
- Longer acting; sandwich
If Deteriorating: consider IM /SC 1mg Glucagon
how would you manage acute hypoglycaemia in a drowsy/confused patient ?
If swallow is intact;
- Buccal glucose
- Hypostop / glucogel
- > Consider IV access
Poor swallow OR unconscious;
- IV Access
- 50 ml, 50 % glucose mini-jet
- 100ml, 20% glucose
Deteriorating / refractory /insulin induced /difficult IV access: consider IM /SC 1mg Glucagon
patient has just had iv treatment for hypoglycaemia, they develop pain, redness, warmth and lump near the venous access site. whats happened?
extravasation of IV glucose: irritant, phlebitis
what 2 things should you remember about giving glucagon?
- mobilises glycogen stores so takes 15-20 mins to work
2. Danger of rebound hypoglycaemia, as will cause insulin release
What level of glucose defines hypoglycaemia?
numerous but generally less than 4
neonates is when it drops < 2.5 mmol/L (K meeran)
Neonate < 2 (according to NICU)
list some symptoms you may see in hypoglycaemia?
Adrenergic
- tremor
- sweating
- palpitations
- hunger
Neuro-glyco-paenic:
- somnolence
- confusion
- seizures, coma
- Incoordination
None
- hypoglycaemic unawareness (lack of adrenergic symptoms during hypoglycaemia)
- If a patient experiences recurrent hypoglycaemic episodes
what is the order of physiological change following the detection of hypoglycaemia?
○ Suppression of insulin
○ Release of glucagon
○ Release of adrenaline
○Release of acth, cortisol, gh
which hormones are involved in glucose counter-regulation?
The action of insulin is counterregulated by glucagon, adrenaline, noradrenaline, cortisol, and growth hormone.
These counterregulatory hormones constitute a principal defense against hypoglycemia, and levels are expected to rise as the glucose falls.
describe the events in glucose counter regulation
Low glucose -> A + B
A. Insulin suppressed + Glucagon increased:
- Reduce peripheral uptake of glucose - Increase glycogenolysis - Increase gluconeogenesis - Increase lipolysis
Subsequently -> inc Glucose + FFA:
FFA -> beta oxidation -> ATP (energy) + ketones
B. low neuronal glucose sensed in hypothalamus
- Sympathetic Activation - catecholamines
- ACTH, cortisol and GH production
how does the hormone profile change in exercise-induced reduction in blood glucose ?
glucagon willl not be released as part of counter regulation, only;
adrenaline, noradrenaline, cortisol, and growth hormone.
how can you measure blood glucose ?
what is the gold standard?
which source of blood?
caveats?
Lab Glucose: Grey top (flouride oxalate) Venous sample 2 mls blood Gold std to make the diagnosis Delay in results
Blood glucose meter -Point-of-care device -Instant result - Capillary blood But… - Poor precision at low glucose levels - Often poorly maintained
aetiology of hypoglycaemia in non-diabetic?
Fasting or reactive? Paediatric vs. adult Critically unwell Organ failure Hyperinsulinism Post gastric-bypass Drugs Extreme weight loss Factitious
aetiology of hypoglycaemia in a diabetic patient?
Diabetic Medications Inadequate CHO intake / missed meal Impaired awareness - due to to autonomic neuropathy Excessive alcohol Strenuous exercise
Co-existing autoimmune conditions - eg Addison’s- polyglandular autoimmune syndrome
Co-existing renal / liver failure alters drug clearance, and reduced doses needed.
which meds are associated with hypoglycaemia and why?
Oral Hypoglycaemic
Sulphonylureas e.g. glicazide
GLP-1 agents
Insulin
Rapid acting with meals: inadequate meal
Long-acting : hypo’s at night or in between meals
Other drugs
B-blockers, salicylates, alcohol ( inhibits lipolysis)
A very good HbA1c level in a diabetic, may be due to ?
reccurent hypos
impaired awareness of hypos may be due to __ ?
autonomic neuropathy
how does continuous glucose monitoring work?
This device is applied to the abdominal wall with a small cannula that sits in the interstitial space in the subcutaneous fat
• The sensor does NOT accurately read blood sugar when it drops below 2.2 mmol/L
How can we differentiate the cause of hypoglycaemia?
history, exam
take blood during hypos then;
biochemical tests; c-peptide, ketones, FFAs
what is c peptide?
utility?
cleavage product of PRO insulin
C-peptide levels are a good marker of beta-cell function
Also good to help differentiate the cause of hypoglycaemia
name some of the pharmacodynamics of insulin vs c-peptide?
Insulin:
Half-life, 4-6 minutes
Hepatic clearance
Exogenous insulin may interfere
C-peptide:
Half-life, ~ 30 minutes
Renal Clearance
Hypoglycaemia due to excess injected insulin would result in what c-peptide level?
LOW c-peptide
because it comes from pro-insulin not insulin/ ready formed insulin
patient presents with hypoglycaemia. what do the following results mean;
a. Low insulin, low C-peptide
b. High insulin, high C-peptide
c. High insulin, low C-peptide
which is the appropriate response to a hypo?
a. Hypoinsulinaemic hypoglycaemia
- appropriate response to a hypo
- not t1dm/dka as they would have hyperglycaemia
b. Hyperinsulinaemic hypoglycaemia - excess endogenous insulin production is causing the hypo
c. Exogenous insulin - injection
What is 3-hydroxybutyrate?
a ketone body
aka beta-hydroxybutyrate
What does the absence of ketones signify
(glucose 1.9, ketones negative)?
Fatty acid oxidation defect
