Diabetic Emergencies Flashcards
What is the triad of DKA
hyperglycaemia
high anion gap metabolic acidosis
ketonaemia
What are some precipitating factors in known diabetes for DKA
inadequate insulin treatment non-compliance infection new-onset diabetes MI stroke acute pancreatitis trauma drugs
How does DKA present
Insulin deficiency causes impaired glucose utilisation as well as increased gluconeogenesis and glycogenolysis resulting in hyperglycaemia
Elevated plasma glucose increases the filtered load of glucose in the renal tubules
As the maximal renal tubular reabsorptive capacity is exceeded glucose is excreted in the urine
The osmotic force exerted by unreabsorbed glucose holds water in the tubules, thereby preventing its reabsorption and increased urine output (osmotic diruresis)
This leads to dehydration and loss of electrolytes
What are the 3 ketone bodies produced in DKA
2 ketoacids and one neutral ketone (acetone)
What might a patient in DKA present with
polyuria and polydipsia resulting in dehydration
abdominal pain and vomiting
fatigue, weakness and weight loss
confusion, coma
What is the term given to deep sighing respiration secondary to acidosis
Kussmaul’s respiration
What does the diagnosis of DKA require
plasma glucose >11mmol/L
Positive urinary ketones or plasma ketones >3mmol/L
acidosis (pH
What type of acidosis in DKA
metabolic acidosis (associated with low bicarbonate levels and a reduction of partial pressure of carbon dioxide due to compensatory hyperventilation with a high anion gap
What should be performed in any patient presenting with DAK
ECG and septic screen
What are some other causes of a high anion gap metabolic acidosis
lactic acidosis (due to tissue hypo perfusion caused by hypovolaemia, cardiac failure or sepsis) renal failure and drugs such as aspirin, methanol and ethylene glycol
What does the treatment of DKA include
Resuscitation (ABCDE) insulin fluids potassium Broad spectrum AB if infection is suspected
Why should patients remain nil by mouth for at least 6 hours
gastroparesis is common
What is the only indication for delaying insulin in DKA
a serum potassium less than 3.3.mmol/L as insulin will worsen the hypokalaemia by driving potassium into the cells
How much insulin is given in DKA
50U of soluble insulin to 50ml 0.9% saline
If the patient is not eating and drinking, what should be used in DKA
Sliding scale
When is dextrose given
when the blood glucose reaches 15mmol/L
What does insulin deficiency lead to in terms of potassium
potassium movement out of the cells and into the extracellular fluid
Why must potassium be given in DKA
treatment with insulin lowers the potassium concentration and may cause severe hypokalaemia as potassium shifts into the cells under the action of insulin
What is monitored hourly for the first 15 hours
blood glucose
capillary ketones
urine output
What is monitored 4 hourly
urea and electrolytes
How often are capillary ketones monitored
2 hourly
What is a serious complication in children with DKA
cerebral oedema
What are some signs of cerebral oedema
Headache recurrent vomiting age-inappropriate incontinence irritability lethargy altered levels of consciousness
How can we treat cerebral oedema
reducing the rate of fluid administration
administer IV mannitol
Describe HHS
Hyperosmolar hyperglycaemic state - there is little or no ketoacid accumulation
the serum glucose often exceeds 50mmol/L
plasma osmolality may reach 380mosmol/kg
neurological abnormalities are frequently present
insulin levels are insufficient to allow appropriate glucose utilisation but are adequate to prevent lipolysis and subsequent ketogenesis
In what population does HHS usually occur
elderly patients with type 2 diabetes
What are the clinical presentations of HHS
insidious onset of polyuria and polydipsia
severe dehydration
neurological symptoms
What investigations are required for HHS
serum glucose serum sodium
what is the treatment for HHS
rehydration until rehydrated
potassium is given in each litre of IV fluid
IV insulin at a rate of 203U per hour
Treat underlying cause
thromboprophylaxis with low molecular weight heparin
Describe how hypoglycaemia arises in diabetics
insulin is supplied exogenously and its release cannot be turned off
The glcoagon and adrenaline response to hypoglycaemia becomes impaired later in the course of diabetics
What are some symptoms of sympathetic overactivity
sweating anxiety tremor tachycardia palpitations pallor nausea hunger
What are some signs of neuroglycopenia
dizziness headache visual disturbances focal neurological defect difficulty speaking inability to concentrate abnormal behaviour confusion drowsiness loss of consciousness or seizure
What is hypoglycaemic unawareness
When the plasma glucose falls without any warning
What does diabetic nephropathy do in terms of insulin requirements
it decreases them as insulin is partly degraded by the kidney
What is the treatment for hypoglycaemia in a patient that is conscious sad cooperative
50g of oral glucose
Lucozade, milk or 3 dextrose tablets
What is the treatment for hypoglycaemia in a patient with reduced levels of consciousness
50ml of 50% glucose IV
If no IV access then 1mg of glucagon IM
What should be given in those with a history of excess alcohol intake
IV thiamine prior to dextrose to reduce the risk of precipitating Wernicke’s encephalopathy
