DKA

Question 1

What is DKA?

Answer 1

acute decompensation due to insulin deficiency
& glucagon excess
fat is used as an alternative energy supply –> keto-acids produced as a by-product

Question 2

What “common” clinical feature is NOT part of DKA?

Answer 2

Fever!

TF if febrile suspect sepsis as a trigger

Question 3

What are the clinical features of DKA?

Answer 3

drowsiness, LOC, coma 
vomiting
abdo pain
thirst & polyuria (osmotic diuresis)
hypotension & dehydration
acetone smelling breath
hyperventilation (kussmaul breathing)

Question 4

What would these signs show that is important to look for in DKA:
headache, irritability, slowing HR, rising BP, reducing LOC, papilloedema (late sign)?

Answer 4

evidence of cerebral oedema

Question 5

What is the Rx for cerebral oedema?

Answer 5

mannitol
or
hypertonic saline

Question 6

if someones pH is 7.2, how serious DKA is that?

Answer 6

pH of > 7.1 = mild /moderate DKA

Question 7

Is someones DKA is 7.0 how serious DKA is that?

Answer 7

pH < 7.1 = severe DKA

–> consider HDU or one-to-one nursing

Question 8

What are the diagnostic biochemical features of DKA?

Answer 8

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

Question 9

What levels of hyperglycaemia indicate DKA?

Answer 9

> 11.1 mmol/L

= same as random glucose diabetes threshold

Question 10

What levels of ketonemia indicate DKA?

Answer 10

> 3 mmol/L
or
Urine ketones

Question 11

What pH levels and other tests show metabolic acidosis?

Answer 11

pH < 7.3

Bicarb < 15 ( – raised anion gap e.g. cations - anions)

Question 12

What is the pattern of potassium derrangement with DKA?

Answer 12

K+ is HIGH initiallly: due to acidosis causing transcellular shift (H+ in, K+ out)
WITH TREATMENT: K+ FALLS. K+ enters cells & urine loss

Question 13

What is the aetiology of DKA?

Answer 13

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

Question 14

What is the pathophysiology of T1DM –> DKA

Answer 14

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

Question 15

What is the a general overview of the Rx for DKA?

Answer 15

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)

Question 16

What is the major risk of fluid replacement in DKA & how do we overcome this?

Answer 16

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

Question 17

What fluid replacement initially should be given if systolic BP is < 90 mmHg?

Answer 17

give 10 ml/kg saline bolus

Question 18

How much dehydration do you assume if pH is > 7.1 (mild/moderate DKA)?

Answer 18

5%

Question 19

How much dehydration do you assume if pH is < 7.1 (severe DKA)?

Answer 19

10%

Question 20

What do you do while replacing fluids in DKA (slowly over 48hrs)?

Answer 20

VBG

–> pH, bicarb, lab glucose, ketones, U&E (K+ and Na+)

Question 21

When do you do insulin replacement?

Answer 21

once the blood glucose is starting to fall according to VBG assessment of fluid replacement
e.g. 1-2 hrs from beginning IV fluids

Question 22

What insulin do you use for replacement?

Answer 22

0. 05 - 0.1 u/kg/h

- -> continue patients LONG ACTING insulin

Question 23

How do you assess the insulin replacement Rx?

Answer 23

Check the VBG!
(bicarb, gluocose, K+)
@ 1h, 2h and 2hrly therefore after
e.g. 1h, 2h, 4h, 6h etc

Question 24

What is the measurement of K+ replacement bags?

Answer 24

20 mmol in 500ml fluid bags

typical deficit is ~4mmol/Kg

Question 25

When do you start replacing K+?

Answer 25

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

Question 26

How do you avoid hypoglycaemia in DKA Rx?

Answer 26

when the glucose is <14mmol/L

start 10% glucose @125mL/hr to run alongside the saline

Question 27

What are the values of ketones, venous pH and bicarb you should continue fixed rate insulin until?

Answer 27

until ketones <0.3mmol/L (from >3 / urine ketones ++)
venous pH >7.3 (from <7.3)
bicarb >18mmol/L (from <15)

Question 28

What are the criteria for HDU/PICU?

Answer 28

if coma,
pH < 7.1
or pt is < 1 y/o

Question 29

What monitoring should be done?

Answer 29

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)

Question 30

What risk do children have of VTE in the DKA population?

Answer 30

there is a significant risk of FEMORAL vein thrombosis in children with DKA who have FEMORAL lines inserted