DKA Flashcards
What is DKA?
acute decompensation due to insulin deficiency
& glucagon excess
fat is used as an alternative energy supply –> keto-acids produced as a by-product
What “common” clinical feature is NOT part of DKA?
Fever!
TF if febrile suspect sepsis as a trigger
What are the clinical features of DKA?
drowsiness, LOC, coma vomiting abdo pain thirst & polyuria (osmotic diuresis) hypotension & dehydration acetone smelling breath hyperventilation (kussmaul breathing)
What would these signs show that is important to look for in DKA:
headache, irritability, slowing HR, rising BP, reducing LOC, papilloedema (late sign)?
evidence of cerebral oedema
What is the Rx for cerebral oedema?
mannitol
or
hypertonic saline
if someones pH is 7.2, how serious DKA is that?
pH of > 7.1 = mild /moderate DKA
Is someones DKA is 7.0 how serious DKA is that?
pH < 7.1 = severe DKA
–> consider HDU or one-to-one nursing
What are the diagnostic biochemical features of DKA?
1) D - Diabetes
2) K - Ketonemia
3) A - metabolic Acidosis
4) hypo-insulinaemia
5) osmotic fluid loss (e.g. blood is conc. w/glucose)
6) derranged potassium
What levels of hyperglycaemia indicate DKA?
> 11.1 mmol/L
= same as random glucose diabetes threshold
What levels of ketonemia indicate DKA?
> 3 mmol/L
or
Urine ketones
What pH levels and other tests show metabolic acidosis?
pH < 7.3
Bicarb < 15 ( – raised anion gap e.g. cations - anions)
What is the pattern of potassium derrangement with DKA?
K+ is HIGH initiallly: due to acidosis causing transcellular shift (H+ in, K+ out)
WITH TREATMENT: K+ FALLS. K+ enters cells & urine loss
What is the aetiology of DKA?
1) ~35% of cases are INFECTION trigger
2) 25% - non-complicance with Rx
3) 13% - inappropriate insulination - alterations by Dr OR pt
4) ~15% - new diagnosis
5) 1% - MI
What is the pathophysiology of T1DM –> DKA
B-cell destruction –> insulin deficiency –> dc glucose utilisation + increased gluconeogenesis –> hyperglycaemia –> osmosic diuresis –> weight loss + polydipsia/uria –> dehydration
The insulin deficiency also –> increased lipolysis –> ketonuria and ketoacidosis –> metabolic ketoacidosis
What is the a general overview of the Rx for DKA?
Primary: 1) call for help as a junior 2) ABCDE approach 3) 2x large bore cannulae 4) bloods to confirm DKA 5) ECG may show T wave changed due to hyperkalaemia 6) NG tube? - if semi- or unconscious (avoid aspiration pneumonia Rx: 1) --> fluid replacement (as dehydrated) 2) --> insulin replacement NB: avoid hypoglycaemia 3) --> assess K+ replacement need 4) --> LMWH for all patients 5) --> avoid hypoglycaemia (by giving glucose when < 14mmol) IDENTIFY + TREAT CAUSE (med reviews @2h then 4hrly e.g. 2h then 6hrs)
What is the major risk of fluid replacement in DKA & how do we overcome this?
cerebral oedema!
so correct fluids - using isotonic saline - slowly over 48hrs
- @ 1L per hour
so for the typical deficit being 5-8L - 5-8hrs IV
Reassess @ 12 hours
What fluid replacement initially should be given if systolic BP is < 90 mmHg?
give 10 ml/kg saline bolus
How much dehydration do you assume if pH is > 7.1 (mild/moderate DKA)?
5%
How much dehydration do you assume if pH is < 7.1 (severe DKA)?
10%
What do you do while replacing fluids in DKA (slowly over 48hrs)?
VBG
–> pH, bicarb, lab glucose, ketones, U&E (K+ and Na+)
When do you do insulin replacement?
once the blood glucose is starting to fall according to VBG assessment of fluid replacement
e.g. 1-2 hrs from beginning IV fluids
What insulin do you use for replacement?
- 05 - 0.1 u/kg/h
- -> continue patients LONG ACTING insulin
How do you assess the insulin replacement Rx?
Check the VBG!
(bicarb, gluocose, K+)
@ 1h, 2h and 2hrly therefore after
e.g. 1h, 2h, 4h, 6h etc
What is the measurement of K+ replacement bags?
20 mmol in 500ml fluid bags
typical deficit is ~4mmol/Kg
When do you start replacing K+?
when the urine output is > 30 ml/h
& the K+ is < 5.5
e.g. using 40mmol/L IV fluid [20mmol in 500ml fluid bags]
NB: if K < 3.5 need HDU/ICU help
How do you avoid hypoglycaemia in DKA Rx?
when the glucose is <14mmol/L
start 10% glucose @125mL/hr to run alongside the saline
What are the values of ketones, venous pH and bicarb you should continue fixed rate insulin until?
until ketones <0.3mmol/L (from >3 / urine ketones ++)
venous pH >7.3 (from <7.3)
bicarb >18mmol/L (from <15)
What are the criteria for HDU/PICU?
if coma,
pH < 7.1
or pt is < 1 y/o
What monitoring should be done?
All the time: strict fluid balance (input/output) hourly: BP and vital signs including GCS blood glucose 1-2 hourly: blood ketones 2-4 hrly: plasma Na, K, Cl, urea, acid base (pH, pCO2) 12hrly: weight ECG looking for hyperkalaemia (t wave changes)
What risk do children have of VTE in the DKA population?
there is a significant risk of FEMORAL vein thrombosis in children with DKA who have FEMORAL lines inserted
