Diabetes Mellitus Type 1 Flashcards
Definition
Fasting glucose level ≥7 mmol/L
Or
random ≥11.1 mmol/L
Caused by destruction of pancreatic insulin-producing beta cells
Autoimmune process
Occurs in genetically susceptible individuals with an environmental trigger
Autoantigens associated with T1DM:
- Glutamic acid decarboxylase (GAD)
- Insulin
- Insulinoma-associated protein 2
- Cation efflux zinc transporter
Epidemiology
0.25% prevalence in the UK
Symptoms
Juvenile onset (< 30 yrs)
Polyuria/nocturia
Polydipsia
Tiredness
Weight loss
DKA Symptoms:
- Nausea and vomiting
- Abdominal pain
- Polyuria, polydipsia
- Drowsiness
- Confusion
- Coma
- Kussmaul breathing
- Ketotic breath
- Signs of dehydration
Signs of complications:
- Fundoscopy - check for diabetic retinopathy
- Examine feet for evidence of neuropathy (monofilament test, pulses)
- Monitor BP
Signs of associated autoimmune conditions
- Vitiligo
- Addison’s disease
- Autoimmune thyroid disease
Investigations
Blood Glucose - fasting blood glucose > 7 mmol/L or random blood glucose > 11.1 mmol/L
HbA1c
FBC - MCV, reticulocytes
U&Es - monitor for nephropathy and hyperkalaemia
Lipid profile
Urine albumin creatinine ratio - used to detect microalbuminuria
Urine - glycosuria, ketonuria, MSU
Investigations for DKA
FBC (raised WCC without infection in DKA)
U&Es (raised urea and creatinine due to dehydration)
- LFT
- CRP
- Glucose
- Amylase
- Blood cultures
- ABG (metabolic acidosis with high anion gap)
- Blood/urinary ketones
Management
Glycaemic Control
Advice and patient education
- Short-acting insulin (three times daily before meals):
- Lispro
- Aspart
- Glulisine
- Long-acting insulin (once daily):
- Isophane
- Glargine
- Detemir
Insulin pumps
DAFNE courses (dose adjustment for normal eating)
Monitor
- Regular capillary blood glucose tests
- HbA1c every 3-6 months
Screening and management of complications
Treatment of hypoglycaemia
- If reduced consciousness: 50 ml of 50% glucose IV OR 1 mg glucagon IM
- If consciousness and cooperative: 50 g oral glucose + starchy snack
Screening and management of cardiovascular risk factors
DKA Management
- 50 U soluble insulin in 50 mL of normal saline
- Use an insulin sliding scale
- Continue until:
- Capillary ketones < 0.3
- Venous pH > 7.30
- Venous bicarbonate > 18 mmol/L
- From this point onwards change to SC insulin
- Don’t stop the insulin infusion until 1-2 hrs after the SC insulin has restarted
- 500 mL normal saline over 15-30 mins until SBP > 100
- Potassium replacement (because insulin drives potassium into cells)
- Monitor blood glucose, capillary ketones and urine output hourly
- Monitor U&Es and venous blood gas
- Broad spectrum antibiotics if infection is suspected
- Thromboprophylaxis
- NBM for at least 6 hrs
- NG tube if GCS is reduced
Complication
Diabetic ketoacidosis
- Can be precipitated by infection, errors in management of diabetes, newly diagnosed diabetes, idiopathic
Microvascular complications:
- Retinopathy
- Nephropathy
- Neuropathy
Macrovascular complications:
- Peripheral vascular disease
- Ischaemic heart disease
- Stroke/TIA
Increased risk of infection
Complications of treatment:
- Weight gain
- Fat hypertrophy at insulin injection sites
- Hypoglycaemia
- Personality changes
- Fits
- Confusion
- Coma
- Pallor
- Sweating
- Tremor
- Tachycardia
- Palpitations
- Dizziness
- Hunger
- Focal neurological symptoms
Prognosis
Depends on early diagnosis, good glycaemic control and compliance with treatment and screening
Vascular disease and renal failure are the main causes of increased morbidity and mortality
