DKA Flashcards
triad in DKA
ketoanaemia/ketouria (2+ on dipstick or >3 using BM machine)
hyperglyc (blood gluc >11 or known DM)
acidosis <7.3
need 2/3 to dx
precipitating factors
- infection
- discontinuation/inadequate insulin
- stroke/MI
- drugs
- physiological stress: preg, trauma, surgery
what drugs may precipitate DKA (4)
steroids, thiazides, alpha/beta blockers
px
polyuria polydipsia vomiting dehydration altered mental state signs of gross dehydration tachypnoea/Kussmaul resp (resp compensation for met acidosis) pear drop breath
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cap and plasma gluc
urinalysis
FBC (WCC may be raised due to sepsis, but also occurs in DKA anyway)
-U+Es: Na and K may go up or down for various reasons, urea and creatinine raised due to AKI
-ABG
-plasma osmolality (calculate it). increased in HHS and DKA but much higher in HHS
-anion gap (calculate it)
-trop, ECG, CXR, abdo cxr, LP if want to rule out infection/cardiac causes
-CT/MRI head may be needed for ddx for impaired consciousness
ddx
alcoholic ketoacidosis HHS actic acidosis metabolic acidosis acute pancreatitis sepsis acute abdomen ketoacidosis due to starvation
rx
ABCDE 1. N saline 1L over 1hr (give 500 ml blus over 10-15 mins if SBP<90. Again if still low. Then call senior if still low) 2. 1L with KCl over next 4 hr 3. 1L with KCl over next 4 hr 4. 1L with KCl over next 6 hr
obviously, be cautious in elderly, heart/kidney failure
fluid resus + insulin
treat any precipitating illness
how to assess severity
blood ketons bicarb level blood ph hypokalaemia GCS <12 o2 <92% systolic bp <90 HR high or low anion gap >16
most important intervention
fluid replacement followed by insulin admin
what fluid replacement type
0.9% saline
+5% dex if glucose <12 (to prevent over-rapid correct of blood gluc)
what rate of insulin infusion
FIXED RATE INSULIN INFUSION!!
IV 0.1 units/kg/hr
70 kg man = 7 units/hr
what does the fluid do
restore circulating volume
remove ketones
correct electrolyte imbalance
there are various targets for reduction in blood ketons, bicarb and cap glucose - but probs too much to learn!!
if these rates are not achieved then insulin infusion rate should be increased
complications of DKA
cerebral oedema iatrogenic hypoglyc iatrogenic hypokal myocardial suppresion due to met acidosis MI VTE cardiac dysrhythmia
how much potassium
over 5.5 -> none
3.5-5.5 -> 40 mmol (this is given with the second bag of fluid - 20 mml/hr)
<3.5 = senior review/get ITU involved
