Diabetic Emergencies Flashcards
What is the pathophysiology of DKA?
- Reduced insulin levels in the blood leads to the increase of serum glucose - this causes a hyperglycaemic state and so osmotic diuresis occurs leading to polyuria, dehydration and polydipsia.
- The lack of insulin also causes uncontrolled lipolysis which produces fatty acid chains that are converted to ketone bodies.
- Ketone bodies then cause acidosis which overwhelms the body’s buffering mechanisms.
What is the diagnostic triad of DKA?
- Serum glucose > 11mmol/L
- Ketones >3mmol/L
- pH <7.3
Main causes of DKA…
- Infection
- Underlying disease e.g. pancreatitis, MI
- Inadequate insulin - poor compliance
- Medications e.g. thiazide diuretics, steroids
Presentation of DKA…
Symptoms:
- Non-specific abdominal pain
- Nausea and vomiting
- Polyuria
- Polydipsia
- SoB
Signs:
- Signs of dehydration : reduced skin turgor, dry mucous membranes
- Ketone breath (pear drops)
Assessment of DKA…
A-E approach required:
- IV access gained with two cannulae
- Bloods:
- Plasma glucose
- Ketones
- FBC - raised WCC indicates infection
- U&E - check for AKI , electrolyte abnormalities e.g. hyperkalaemia
- VBG - check for metabolic acidosis
- Other bloods e.g. amylase, TFTs, troponin - depending on suspicion
- ECG - look for arrhythmias caused by electrolyte abnormalities
Differential diagnosis for high anion gap metabolic acdosis…
MUDPILES: Methanol Uraemia (renal failure) DKA Paracetamol Infection Lactic acidosis Ethylen glycol Salicylates
Management of DKA…
- Primary goal = aggressive fluid resuscitation as patients are severely dehydrated
- Give 2L 0.9% saline STAT
- Then continuous saline infusion of 0.5L/hr for 4 hours then 0.25L/hr
INSULIN = fixed rate Actrapid infusion at 0.1 units/kg/hr
along with their normal long-acting insulin
Insulin may cause hypokalaemia so add 40mmol/L to saline infusion if K+ is between 3.5-5.5
When plasma glucose <11.1, switch saline to 5% dextrose
When DKA has resolved (all criteria have returned to normal) :
- If pt is eating and drinking - switch back to normal insulin regime
- If pt not eating and drinking - switch to variable rate insulin infusion
*VTE risk - give LMWH
How can you tell if DKA management is working?
- Blood ketones fall by 0.5mmol/L/hr
- Glucose falls by 3mmol/L/hr
- Resolving pH on VBG
Why is it important to give long acting insulin along with the fixed rate infusion in DKA?
Will improve background control of blood sugar and so transition to normal insulin regime will be easier.
Management of DKA in children…
Not clinically dehydrated: give oral fluids and SC insulin
Clinically dehydrated/ vomiting:
- Give fluid bolus if pH<7.1 (10ml/kg)
- Then give maintenance fluid infusion - depending on weight : <10kg = 2ml/kg/hr , 10-40kg =1ml/kg/hr, >40kg=40ml/hr
- Start IV insulin infusion 2 hours after fluid infusion - rate=0.05-0.1 units/kg/hr
What is the key clinical features of HHS…
- Plasma glucose > 30mmol/L
- Plasma osmolality > 320mmol/kg
- Normal ketones
- No metabolic acidosis
- Hypovolaemia
How does HHS present?
- Normally seen in T2DM patients
- Very common in the elderly, living in care homes, dementia
- Gradual onset over a few days of dehydration and metabolic disturbances
Sx= weakness+ lethargy, N+V, headache, increasingly drowsy, dehydrated
Causes of HHS…
- Infection
- Underlying disease - stroke, MI
- Medication induced - diuretics, glucocorticoids
- Poor compliance with medication - common in elderly
Complications of HHS…
- VTE
- AKI
- Circulatory collapse - shock
Investigations in HHS…
Bloods:
- Plasma glucose
- Serum osmolality - Na+,glucose, urea
- FBC - raised WCC in infection
- U&Es for electrolyte abnormalities
- ABG - normal
- Other bloods depending on suspected cause
Management of HHS…
Fluid resuscitation: IV 0.9% Saline - gradual in elderly:
1L bolus over first 60 mins, then 1L/2hr for 4 hrs, then 1L/6hr until rehydrated
Potassium replacement if K+ between 3.5-5.5 = 20mmol added to saline infusion
Begin insulin therapy if blood glucose is not falling from adequate fluid resuscitation alone OR significant ketonaemia:
- Fixed rate insulin 0.05 units/kg/hr
- Blood glucose needs to fall by 3mmol/hr - target = 10-15mmol/L
*VTE risk - give LMWH
What are some indications for ITU in a diabetic emergency?
- Ketones >6
- pH <7.1
- Hypokalaemia
- GCS <12
- Oxygen sats <92%
- UO <0.5ml/kg/hr
What steps should be taken if inpatient is found to be hyperglycaemic with no acidosis?
- Identify if patient is at risk of DKA : infection, underlying illness, any other medications they are taking
- Look for signs of dehydration e.g. dry mucous membranes
- Look at glucose measurements over last 24 hrs - isolated event?
- Review medication chart - insulin administered
- Any other cause for hyperglycaemia e.g. food intake
- Check HbA1c for long term picture over glycaemic control
What is the definition of hypoglycaemia?
Blood glucose <3.9mmol/L
What is Whipple’s triad for hypoglycaemia?
- Low blood glucose
- Symptoms of hypoglycaemia
- Resolution os symptoms with glucose given
Risk factors for hypoglycaemia…
- Excessive insulin dosage
- Malabsorption (decreased glucose absorption)
- Alcohol (decreased glucose synthesis)
- Exercise (increased glucose use)
- Renal failure (reduced insulin clearance)
- Increased age
What is hypoglycaemic unawareness?
Repeated epsiodes of hypoglycaemia lead to reduced adrenaline release with hypoglycaemia therefore fewer symptoms of hypoglycaemia occur so there is reduced awareness
Presentation of hypoglycaemia…
Neuro sx = drowsy, confused, odd behaviour
Autonomic sx= sweating, palpitations, shaking
General = headache, nausea
What kind of seziures can occur from hypoglycaemia?
Unresolved hypoglycaemia may lead to seizures:
- Generalised normally but focal seizures also seen
- Lateralised weakness
What is the definition of severe hypo?
Episode of hypoglycaemia that requires another person’s help
*DVLA need to be informed if >1 sever hypo in a year
Management of hypo…
Patient who is conscious and able to swallow:
- Give 15-20g of fast acting carb - dextrose tablets, 100ml lucozade
- Chek BM atfer 15 mins:
- >4mmol/L = give long acting carb e.g. biscuit
- <4mmol/L = repeat step 1 up to 3 times until >4mmol/L, then give long acting carb - If after 3 attempts <4mmol/L, give 1mg Glucagon IM
Patient who is unconscious/ unable to swallow:
- A-E assessment and stop any insulin infusion
- Give 1mg Glucagon IM
- Check BM every 15 mins until 2 readings >4mmol/L
- If <4mmol/L- repeat step 2
- When >4mmol/L give long acting carb e.g. biscuit
Mesenchymal tumours causing hypoglycaemia…
Non-islet cell tumour hypoglycaemia (NICTH) is normally seen in mesenchymal tumours (tumour of mesodermal derived tissue), NICTH is a paraneoplastic syndrome
The most common type is overproduction of IGF-2 which leads to stimulation of the insulin receptors causing increased glucose utilisation.
What is an insulinoma?
Benign islet cell tumour which causes frequent episodes of hypoglycaemia.
Presentation of insulinoma…
- Sx of hypoglycaemia - mainly seen in the morning/ before meals
- Rapid weight gain may be seen
Diagnosis of insulinoma …
- Plasma glucose <2.2 when fasted
- High serum insulin
- High C-peptide (indicates insulin is endogenous)
- CT/MRI of pancreas with tissue biopsy
Management of insulinoma…
- Surgery is definitive treatment
- Diazoxide and ocreotide (somatostatin) can be used to suppress insulin release if not suitable for surgery
What is reactive hypoglycaemia?
Symptomatic hypoglycaemia that occurs in non-diabetic patients after a high-carbohydrate meal
Management of reactive hypoglycaemia…
- Avoid refined carbohydrates e.g. white bread, pizza, pasta
- Small frequent meals are best
What is factitious hypoglycaemia?
Patients who intentionally try to induce hypoglycaemia by excessively administering insulin/ sulfonylureas
What is Addison’s disease?
Addison’s disease = primary adrenal insufficiency i.e. there is something wrong with the adrenal gland, leading to reduced secretion of adrenal hormones- mineralocorticoids (aldosterone) , glucocorticoids (cortisol)
Causes of Addison’s disease…
- Autoimmune adrenalitis = most common
- Infection - TB, HIV
- Haemorrhage
- CAH
Features of Addison’s disease…
- Lethargy, weakness
- Weight loss
- Hyperpigmentation (due to raised ACTH)
- Hyponatraemia and hyperkalaemia (due to reduced aldosterone)
- Hypoglycaemia
Diagnosis of Addison’s
- 9am serum cortisol =alternative test:
- >500nmol/L = Addison’s unlikely
- <350nmol/L = need short synacthen test - Short synacthen test: cortisol <450nmol/L - diagnostic
Management of Addison’s…
- Replace glucocorticoid: hydrocortisone -3 doses per day
- Replace mineralocorticoid: fludrocortisone
- Steroid card/ bracelet
- Education about sick day rules: double the hydrocortisone dose during illness