An approach to patient with hyperglycaemia

Posted: May 22, 2012 by kiamseong in Medicine

Mortality caused by DKA and HHS = 30%

Precipitating factors

  • Noncompliance to medication
  • Infection
  • Pancreatitis
  • Myocardial infarction
  • Steroid
  • Thiazide
  • Stroke etc.


Difference between DKA and HHS

In DKA ~ absolute insulin deficiency –> induce lipolysis –> ketone formation

In HHS ~ relative insulin deficiency


Differential diagnosis

If presence of ketone can be also due to:

  • Starvation
  • Alcohol

 

DKA

To diagnose must fulfil these 3 criteria:

  • pH < 7.3
  • glucose > 14
  • blood ketone > 2

 

Severity:

Mild                        pH 7.25-7.30  HCO3 15-18 Alert

Moderate              pH 7.00-7.24  HCO3 10-14 Drowsy

Severe                    pH <7.00        HCO3 <10 Stupor/Coma

 

HHS

To diagnose must fulfil these 2 criteria:

  • glucose > 33
  • serum osmolarity > 320 mOsm/L
  • HCO3 > 18

 

Mental status drops if osmolarity ­increased

 

Ix

  • DXT
  • Ketone stick
  • ABG/VBG
  • RBS (esp DXT HI)
  • BUSE, Creatinine
  • Serum ketone
  • Serum osmolarity
  • UFEME
  • FBC
  • ECG
  • CXR
  • Blood C+S
  • HbA1c

 

Mx of Hyperglycaemia

  1. Fluid replacement
  2. Insulin
  3. Electrolyte correction
  4. Treat precipitating cause

 

Fluid replacement

Set 1 line in each arm

One for running bolus

One for maintenance

 

For deficit – DKA 6 litres, HHS 9 litres

Run in bolus

1 litre in 1 H

1 litre in 2 H

1 litre in 4 H

1 litre in 6 H

1 litre in 8 H

 

Maintenance calculated by Holliday Segar formula

 

Choice of fluid

If hyperNa or EuNa à use HS

If hypoNa à use NS

 

Always start from fluid replacement because:

  • To prevent hypotension
  • To obtain K+ result before insulin therapy
  • Insulin effectiveness decrease if hyperosmolar not corrected
  • Sufficient fluid therapy decrease counteracting hormones

 

Insulin therapy

Not to start if K < 3.3

IV regular insulin 0.1U/kg bolus then 0.1U/kg/H per sliding scale

Target to reduce glucose level 2.7-3.8 mmol/L/H

  • Not too fast à can cause cerebral oedema
  • If cannot reach target à double the dose

 

Target glucose level: (keep till DKA/HHS resolves)

DKA 8-11mmol/L

HHS 14-16 mmol/L

 

In DKA if patient in hypoglycaemia – cannot stop insulin therapy because it can cause ketoacidosis due to lipolysis

è  To give insulin but give patient on D10%

 

Electrolyte correction

Check BUSE and VBG QID

 

Criteria to start K replacement:

  • No ECG evidence of hyperkalemia
  • K < 5mmol/L
  • Good urine output 0.5cc/kg/H

 

To correct hypokalemia (as a result of insulin therapy), include in each/alternate pint fluid in maintenance drip 0.5-1g KCl

 

Hyperglycaemia resolution (at least 3 criteria)

DKA                                       HHS

Glucose < 11                         Serum osmolarity < 320

HCO3 > 18                            Gradual recovering mental alertness

pH > 7.3                                               

Anion gap < 12  

 

Formula: AG = Na + K – Cl – HCO3

 

After resolve, if patient tolerating orally

Change to basal bolus regime (0.5-0.8 U/kg/day) and titrate with overlapping 1-2hrs with sliding scale

 

Indication of bicarbonates

If pH 6.9-7, gives 50cc HCO3 in 200cc HS with 10ml KCl over 2hrs

If pH < 6.9 gives double dose

 

Be aware of fluid overload in elderly or when massive replacement is required. Consider CVP monitoring.

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