Diabetic Ketoacidosis Flashcards
define diabetic ketoacidosis?
acute metabolic complication of diabetes that is potentially fatal and needs urgent medical treatment for successful treatment characterised by absolute insulin deficiency
most common acute hyperglycaemic complication of type 1 diabetes mellitus
outline the aetiology of ketoacidosis?
- In DKA, there is a reduction in the net effective concentration of circulating insulin along with an elevation of counter-regulatory hormones (glucagon, catecholamines, cortisol, and growth hormone).
- The two most common precipitating events are inadequate insulin therapy and infection. Inadequate or inappropriate insulin therapy increases likelihood of DKA
outline the pathophysiology of ketoacidosis?
Reduced insulin concentration or action, along with increased insulin counter-regulatory hormones, leads to the hyperglycaemia, volume depletion, and electrolyte imbalance that underlie the pathophysiology of DKA
. Hormonal alterations lead to increased gluconeogenesis, hepatic and renal glucose production, and impaired glucose utilisation in peripheral tissues-> results in hyperglycaemia and hyperosmolarity.
Insulin deficiency leads to release of free fatty acids from adipose tissue (lipolysis), hepatic fatty acid oxidation, and formation of ketone bodies (beta-hydroxybutyrate and acetoacetate), which result in ketonaemia and acidosis.
elevation of pro-inflammatory cytokines and inflammatory biomarkers (e.g., C-reactive protein [CRP]), markers of oxidative stress, lipid peroxidation, and cardiovascular risk factors with hyperglycaemic crises
what are the signs and symptoms of DKA?
due to hyperglycaemia
- polyuria
- polydispsia
- weight loss
- weakness
due to acidosis/ketosis
- N + V-> due to high levels of ketones maybe trying to get rid of them
- Ado pain-> use abdo muscles due to labored breathing
- kussmaul resp- deep sighing breathing
- acetone breath
- altered mental state - drowsy
due to volume depletion
- dry mucous membrane
- poor skin tugour
- sunken eyes
- tachycardia
- hypotension
- confusion
what investigations should be ordered for DKA?
venous blood gas
blood glucose
blood ketones
urea and electrolytes
FBC
what is the result for venous blood gas in DKA
METABOLIC ACIDOSIS
RAISED ANION GAP ( between chloride and bicarbonate) -low bicarb and acidosis
what is the result for blood ketones in DKA?
ketonaemia (ketones ≥3.0 mmol/L)[42]
which drugs can cause errors in detecting ketone bodies?
ACE inhibitor captopril, contain sulfhydryl groups that can react with the reagent in the nitroprusside test (used to test for ketone bodies) to give a false-positive reaction. Therefore, use clinical judgement and other biochemical tests in patients who are taking these medications.
what is the blood glucose result in DKA?
hyperglycaemia (blood glucose >11.1 mmol/L)
What is the result for urea and electrolytes in DKA?
hyponatraemia and hyperkalaemia are common but hypokalaemia is an indicator of severe DKA
may show hypomagnesaemia and hypophosphataemia
what does hypernatraemia indicate in DKA?
Hypernatraemia with hyperglycaemia indicates severe dehydration
What does hypokalaemia indicate in DKA?
severe total-body potassium deficit and is an indicator of severe DKA
because total body potassium concentration is low due to increased diuresis.
what may be the cause of hyperkalaemia in DKA?
due to an extracellular shift of potassium caused by insulin insufficiency, hypertonicity, and acidosis.
what may the FBC show in DKA?
leukocytosis- Leukocytosis is common in DKA and correlates with blood ketone levels
what other investigations should you consider for DKA?
Blood gas, urine dip, ESR, CRP and CXR to check for infection
outline the management for DKA?
1) IV fluids – isotonic saline
a) largebore cannula with 2 sites one for insulin and the other for fluids
b) 1L of 0.9 NaCl
2) Potassium therapy – as insulin drives potassium into cells
3) IV insulin once serum pot reaches 3.3 mmol/L
a) Can give bolus then Infusion
b) Continue until no ketone in urine – if bgl is falling then give dextrose
SIDE NOTE: when glucose reaches 11.1mmol,salinefluid should be changed to 5% dextrose to prevent hypoglycaemia
4) If hemodynamically unstable, may need vasopressor therapy (e.g. dopamine)
5) Consider bicarbonate and phosphate therapy depending on levels - but some say that giving bicarb will acc worsen it
a) Bicarbonate therapy may be necessary in adults with pH <7 or bicarbonate level <5mmol/L
6) Some pts with DKA May need a central venous catheter to guide fluid replacement esp if they have renal or heart fail
7) Educate about prevention
