Diabetic emergencies Flashcards
What is diabetic ketoacidosis?
Metabolic acidosis due to accummulation of ketone bodies in the serum of patients with (usually Type 1 diabetes).
What causes DKA?
- Although there is excessive glucose in the bloodstream, a lack of insulin to prevents glucose up-take into cells
- The body is put in a starvation-like state where ketones are produced as an energy source
- Ketones are relatively strong organic acids and when present in high concentrations in the plasma, they cause a metabolic acidosis
Why do patients with DKA have a fruity smelling breath?
- Acetone is volatile and can be excreted via the lungs - it has a fruity smell
- Acetone is one of the ketones produced in the body (the other 2 are acetoacetate and beta-hydroxybutyrate)
- Ketones are produced in response to the low insulin levels in the bloodstream in diabetes
How does low insulin levels in the bloodstream result in ketone production?
- Low plasma/glucagon ratio activates lyase and inhibits reductase
- AcetylcoA is diverted to the pathway that produces ketones rather than cholesterol
Where in the body are ketones produced?
Liver
What is the typical presentation of DKA?
Gradual drowsiness, vomiting and dehydration in a Type 1 diabetic
List 5 symptoms of DKA.
- unexplained vomiting
- abdominal pain
- polyuria
- polydipsia
- lethargy
List 5 signs of DKA.
- Fruity smelling breath
- Weight loss
- Signs of dehydration - dry mucous membranes, reduced skin turgor
- Tachypnoea and deep breathing - Kussmaul hyperventilation
- Confused - deteriorating GCS (can result in coma)
What is the diagnostic triad for DKA?
- Ketonaemia [>3mmol/L or significant ketonuria on dispstick (2+ on urine dipstick)]
- Hyperglycaemia [Blood glucose >11mmol/L or known diabetes mellitus]
- Acidaemia [venous pH<7.3 or bicarbonate<15mmol/L)
What immediate bedsite test should you do in anyone presenting with unexplained vomiting, abdominal pain and drowsiness?
CAPILLARY BLOOD GLUCOSE
How should you assess someone with suspected DKA?
A-E assessment
What tests should you do in a patient suspected to have DKA?
- B - CXR
- C
- ECG
- Bloods - capillary and venous blood glucose, ketones, pH, FBC, U&Es, osmolality, blood culture
- E - dipstick and MSU for MC&S
ABG or VBG in DKA?
VBG usually, only use ABG if reduced GCS or hypoxia
Name 4 common triggers for DKA.
- Infection e.g. UTI, pneumonia
- Inadequate insulin treatment - non-compliance, insulin pump failure
- Surgery
- MI
A patient fulfils the diagnostic criteria for DKA. They have a GCS<12 and hypokalaemia on admission. What are your next steps.
- GCS<12 and hypokalaemia are features of severe DKA
- This may require admission to HDU/ITU and insertion of a venous central line
- Therefore, GET SENIOR HELP IMMEDIATELY
Name 3 features of DKA that would prompt immediate senior review.
- Blood ketones greater than 6mmol/L
- Bicarbonate less than 5mmol/L
- Venous/arterial pH less than7.0
- Hypokalaemia( lessthan3.5mmol/L) on admission
- GCS less than 12 or abnormal AVPU or NEWS* >6
- Oxygen saturation less than 92% (assuming normal respiratory baseline)
- Systolic BP less than 90mmHg
- Pulse greater than 100 or less than 60 bpm
- Anion gap greater than 16 N.B. Anion gap = (Na + K) – (Cl + HCO3)
(The above are all features of severe DKA)
What are the fundamental principles in the management of DKA?
- replacement of fluid deficit
- insulin treatment
- monitoring and maintaining electrolyte/potassium balance in a safe environment
- avoiding complications of treatment
What are the commonest causes of death associated with DKA?
- cerebral oedema - especially in children and adolescents
- hypokalaemia
- ARDS
- co-morbid conditions e.g. pneumonia
- acute MI
- sepsis
What serious complications can arise during the management of DKA as a result of treatment?
- insulin
- hypokalaemia
- hypoglycaemia
- fluid replacement
- cerebral oedema
- pulmonary oedema
- potassium replacement
- hyperkalaemia
Which groups of patients with DKA require extra caution in their care and management to avoid complications?
- young perople 16-25 years
- elderly >70 years
- pregnant
- cardiac or renal failure
- other serious comorbidities
You are the junior doctor in A&E. You have clerked a patient with suspected DKA. Their NEWS score is stable. What are your next steps?
Initiate treatment and immediate senior review
(If NEWS indicated senior review sooner, then senior review immediately before initiating treatment)
You have clerked a patient in A&E with DKA. You have completed your A-E assessment and requested the relavent tests. What are your initial steps in managing this patient?
- Use the correct prescription chart e.g. Adult diabetic ketoacidosis prescription chart
- STEP 1 - insert large bore IV cannula and commence IV 0.9% sodium chloride 1000ml/hr (circle 1000 on prescription chart and sign name)
- STEP 2 - 10 units ActRapid if likely to be delay of longer than 15mins from diagnosis of starting IV insulin (sign name next 10 units of soluble insulin SC)
- STEP 3 - Potassium is often high on admission but falls rapidly with insulin, check VBG and add 20mmol/500ml potassium to infusion as necessary
- STEP 4 - Commence IV fixed rate insulin - 0.1units/kg/hr (if 70kg then put 7 in the initial rate box and sign name)
You have commenced initial management of DKA with 1 litre of 0.9% sodium chloride over an hour and IV fixed rate insulin infusion. What are the next steps?
- Senior review
- Monitor patient closely
- Review the IV fluid regimen based on the patient’s clinical and biochemical assessment
- Consider precipitating causes and treat appropriately
- VTE prophylaxis
- Refer to Diabetes team
Describe how you would monitor a patient with DKA.
- Biochemistry
- Capillary blood glucose and ketones hourly
- VBG for potassium and pH hourly then 2 hourly
- Clinical assessment
- Regular assessment of GCS and vital signs
- Regular assessment of fluid status, monitor input/output
- Cardiac monitoring if severe DKA
What is resolution of DKA defined as?
- Blood ketones <0.6mmol/L
- Venous pH >7.3
You are managing a patient with DKA. The patient is vomiting and drowsy despite initial management. What will you do next?
- Senior review
- Consider NG tube
When prescribing fluids in DKA, what should you tailor the fluid prescription to?
- Hypoglycaemia - when blood glucose <14mmol/L prescribe 10% glucose 500ml alongside sodium chloride
- Hypokalaemia - when potassium 3.5-5.5 add 20mmol/500ml K+ to sodium chloride
- Fluid status - monitor for fluid overload and cerebral oedema (any sudden deterioration in GCS is likely to be cerebral oedema)
What would you expect to see for WCC and Na+ blood results in DKA?
High wcc may be seen in the absence of infection.
Hyponatraemia is common, due to osmolar compensation for the hyperglycaemia. ↑ or ↔ [Na+] indicates severe water loss. As treatment commences Na+ rises as water enters cells.
Does ketonuria always indivate ketoacidosis?
Ketonuria does not equate with ketoacidosis. Anyone may have up to ++ketonuria after an overnight fast. Not all ketones are due to diabetes—consider alcohol if glucose normal. Always check venous blood ketones.
How should you investigate for infection as a cause of DKA?
Often there is no fever. Do msu, blood cultures, and cxr. Start broad-spectrum antibiotics (eg co-amoxiclav, p[link]) early if infection is suspected.
Why do we continue to treat DKA when glucose is <14mmol/L?
Blood glucose may return to normal long before ketones are removed from the blood, and premature termination of insulin infusion may lead to lack of clearance and return to dka. This may be avoided by maintaining a constant rate of insulin infusion (with co-infusion of glucose 10% to maintain plasma glucose at 6–10mmol/L) until blood ketones <0.6mmol/L and pH >7.3.
Pancreatitis can trigger DKA. Is amylase helpful in determining whether pancreatitis is the trigger?
In DKA, serum amylase is often raised (up to ×10) and non-specific abdominal pain is common, even in the absence of pancreatitis.
Once DKA is resolved according to biochemical parameters and patient is feeling better. The patient is due her lunch. How do you stop the fixed rate insulin infusion?
Ensure she takes her subcutaneous rapid-acting insulin before her meal. Then stop the FRII 30-60 mins after S/C insulin.
(This is because the half-life of IV insulin is only 3-4 mins and subcutaneous insulin may take considerably longer to be absorbed)
When treating DKA, what should you with regards to the patients usual insulin regime?
- CONTINUE long acting or intermediate acting insulin with FRII
- Stop the fast-acting meal-time insulin until FRII is stopped