Diabetic KetoacidosisA sweet new approach to an old problem

Outline

DKA background

The new protocol

Approaches in other hospitals

What is it?

• Hyperglycaemia

• Ketosis and acidosis

• Dehydration

• Electrolyte imbalance

Hyperglycaemia

DKA is a state of insulin deficiency

It is also a state of relative excess of glucagon and other hyperglycaemic hormones: catecholamines, cortisol, growth hormone etc

This is likely to be triggered by conditions that result in one of these hormones being elevated Infection Pregnancy Medications (prescribed or non-prescribed) Trauma Burns

Ketosis and acidosis

Due to enhanced gluconeogenesis there is significant lipolysis

Free fatty acids are metabolised into ketone bodies (acetoacetate and beta hydroxybutyrate) which accumulate

Ketone bodies dissociate into ketone anions and hydrogen

The bodies buffering capacity is exhausted leading to excess hydrogen ions

Dehydration• Osmotic diuresis

• Vomiting

• Third space

Electrolyte imbalance

Potassium One third will have K >5.5 All are potassium deplete (~300-600meq) Osmotic diuresis

Sodium Increased osmolality dilutes extracellular sodium Osmotic diuresis causes increased extracellular

sodium

Phosphate Most will develop phosphate depletion but ?

importance of this

The context• No hospital wide policy on

DKA

• Unclear DKA proforma

• Ward to ward variations in practise

The new model

Standardised diagnosis

Check for high risk criteria

Standard fluid orders

Fixed rate insulin dosing

Maintain basal dose insulin

Why the change?

Wide variability makes assessment of outcomes difficult Cerebral oedema in children +/- young adults Pulmonary oedema Hypo/hyperkalaemia Hypoglycaemia

Standardised diagnosis

Fingerprick BSL and ketones

Venous pH/gas unless hypoxic and/or ABG required

Less emphasis on urine ketones

High risk criteria

Any of the following should prompt early senior input and NOSA/ICU review Ketones >6 Bicarbonate <10 pH < 7.1 SpO2 <92% GCS <15 SBP <90 Pulse <60 or >100

Standard fluid orders

Normal saline over 1, 2, 3, 4, 5, 6 hours

Add 40mmol KCl to second and subsequent bags with K <5.5

Fixed rate insulin + basal

No sliding scale until ketoacidosis resolved 0.1units/kg/hr of actrapid in standard concentration Don’t switch it off until you switch it off!

Continue basal insulin regime (lantus/protophane/levemir) and consider basal pump function

As previously, restart usual SC dosing then switch off infusion 30 min later.

Example cases

Mr JL

63yo M

T1DM since age 14, nil prior DKA, usually on pump

Widely metastatic colorectal cancer on informal trial chemotherapy

Recent chesty cough

Priority one with reduced conscious state

HR 100, BP 80/-, SpO2 90% NRBM, T38.2, BSL 35

pH 7.19, pCO2 26, HCO3 9

Na 133, K 5.9, Creat 185

Fingerprick ketone 6.0

Ketones >6

Bicarb <10

pH <7.1

GCS <15

SBP <90

Pulse >100 or <60

Patient severely unwell so standard protocol does not apply

However, don’t throw out the whole idea of the protocol

Changes to protocol

Patient likely to require HDU bed and early review by inpatient team

Continous monitoring

Strict fluid balance chart

More liberal initial fluid resuscitation

More regular blood testing

BUT Fixed dose insulin Ongoing fingerprick ketone

measurement

Mr JG

30yo M

T1DM since childhood

Polysubstance abuse

Priority 3 with abdominal pain

Obs normal

pH 7.28, pCO2 37, HCO3 17

Na 139, K 4.0, Creat 60

BSL 25

Ketones 4

Ketones >6

Bicarb <10

pH <7.1

GCS <15

SBP <90

Pulse >100 or <60

Patient has mild DKA with no high risk features, therefore suitable for standard protocol

Useful resources

Joint British Diabetes Societies guideline for the management of diabetic ketoacidosis (2011), Diabetic Medicine 28: 508-515

Questions?