DKA & HHS Flashcards
What is the criteria for diagnosis HHS?
Dehydration Osmolality >320 mosmol/kg Hyperglycaemia > 30 mmol/l Minimal ketonaemia <3 mmol/l Minimal acidosis - pH >7.3, bicarbonates >15mmol/l
What investigations do you need to do in a patient with suspected HHS?
FBC U&E LFTs Plasma osmolality Venous blood gas - pH, bicarbonate, lactate Plasma glucose Blood ketones HbA1c Blood cultures if septic/febrile Urinalysis ECG, CXR
How do you calculate plasma osmolality?
2Na + glucose + urea
What are the principles of initial management of HHS?
- LMWH prophylaxis
- Fluid hydration - 0.9% sodium chloride
- Insulin treatment - only if meets criteria
- K+ replaced
- Avoid hypoglycaemia - glucose infusion if required
What fluid regimen should you follow in HHS?
0.9% sodium chloride
1,22,44,66,888
1L in 1 hr 1L in 2 hr 1L in 2 hr 1L in 4hr 1L in 4hr 1L in 6hr 1L in 6hr 1L in 8hr 1L in 8hr 1L in 8hr
When would you prescribe insulin in the treatment of HHS?
- Blood glucose failed to fall further after initial fluid resuscitation
- Blood ketones > 1mmol/l
How much K+ would you add to the fluids in HHS management?
Once urine starts to flow…
If > 5.5 None
If 3.5-5.5 40 mmol/l
If <3.5 seek help as additional K+ needed
What CBG should you aim for in patients with HHS and why?
10-15 mmol/l for first 24hours
Avoid cerebral oedema
How can you avoid hypoglycaemia in patients with HHS?
If CBG <14 mmol/l, start glucose infusion while continuing with fluids.
After initial management of HHS, what must you do?
Catheterise - measure fluid balance
Look for cause - sepsis, MI, drugs, bowel infarct
How does HHS present?
Generalised weakness, leg cramps Visual impairment Nausea + vomiting (less than DKA) Confusion Focal neurological symptoms -confused with stroke Seizures (25%)
What signs would you see in HHS?
Tachycardia
Hypotension
Raised RR
What are differential diagnosis for HHS?
Delirium (older patients)
Acute poisoning
Metabolic acidosis
What is the mechanism behind DKA?
Starvation state where lipids are broken down to form FFA which are substrates for ketones.
FFA also substrates for gluconeogenesis, causing hyperglycaemia.
High glucose but no insulin so cannot be taken into cells.
Severe acidosis and hyperglycaemia combination is dangerous.
How does DKA present?
Develops within 24 hours Usually T1DM Drowsiness Vomiting Dehydration Non-specific abdo pain Altered mental state- coma if severe Kussmual respiration (to compensate for acidosis)
What can trigger DKA?
Infection Surgery MI Pancreatitis Wrong insulin dose/non-compliance
How is DKA diagnosed?
- Acidaemia pH<7.3 or HCO3 <15
- Hyperglycaemia >11 mmol/l
- Ketonaemia >3mmol/l or ketonuria > 2+
What investigations should be done if DKA is suspected?
Capillary blood glucose and venous blood gas immediately FBC U&E CRP Blood glucose Urine analysis, MC+S ABG - metab acidosis Plasma osmolality Anion gap raised Blood culture CXR ECG
What changes might you see in electrolytes in a patient with DKA?
Raised Na - dehydration
Raised K+ - metab acidosis
Briefly, how is DKA treated?
LMWH prophylactically
Fluid replacement
Insulin
K+ replacement
What is the fluid regimen for treating DKA?
1
22
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8
How much insulin should you give in DKA?
Infusion of 10 units in 50ml of 0.9% sodium chloride
When should you start giving K+ in DKA?
Not in first bag Once diuresis has started, 20mmol Check VBG and add accordingly: - If >5.5 none - 3.5-5.5 40 mmol/L - <3.5 seek help for higher doses
What happens to K+ levels when you treat DKA?
They fall as K+ is taken up into cells in response to insulin
How is hypoglycaemia avoided in DKA?
Once CBG <14, start 10% glucose infusion
What must be checked hourly in DKA?
CBG and ketones
What happens to the patients long acting insulin regime in DKA?
Give as normal and indicated times
What might you see on FBC in DKA?
Raised WCC despite no infection
How does infection presentation differ in DKA?
Often no fever
Do MSU, blood cultures and CXR
How should ketonuria be interpreted?
Ketonuria alone does not mean ketoacidosis, can have 2+ ketones in urine after overnight fast.
What are complications of DKA?
Cerebral oedema
Aspiration pneumonia
Hypokalaemia
VTE
