Paediatric Diabetic Ketoacidosis

1. Paediatric Diabetic Ketoacidosis

2. Scary Statistics • DKA = most common cause of death in children with IDDM. • 25% of children newly diagnosed with DM1 present in DKA  15% in serious clinical status. • All DKA admissions after diagnosis are avoidable! • Costly  direct and indirect.

3. Management • Emergency management  ABC!! • Airway ensure it’s patent. If comatose, insert an airway. Recurrent vomiting – NG tube, aspirate, leave to open drainage. • Breathing  100% O2 by face mask. • Circulation  insert IV cannula and take blood samples. ECG for T waves (hyperkalaemia)

4. Cont’d If shocked (poor periph pulses, poor cap re-fill with tachycardia and/or hypotension) give 10 ml/kg 0.9% (normal) saline as a bolus, and repeat as necessary to a max of 30 ml/kg. NB. There is no evidence to support the use of colloids or other volume expanders in preference to crystalloids.

5. 2. Confirm the Diagnosis History • Thirst/Polydidsia • Polyuria •  Weight • Nausea/vomiting • Abdominal pain Due to GLYCOSURIA Due to infectious process or metabolic imbalance

6. Cont’d Physical findings  depressed, weak and dehydrated!! • Tachycardia • Hypotension • Dehydration  mild, moderate, severe? • Tachypnoea/Kussmaul • Abdo tenderness  similar to acute appendicitis!! • Fruity odour on breath • Altered mental function  neuro exam and GCS!!! • FULL examination and WEIGH the child!!

7. Cont’d Biochemical • High blood glucose on finger-prick test. • Glucose and ketones in urine.

8. Initial Investigations– What should be checked and what they may show! • Blood Glucose Hyperglycaemia (BM > 11mml/L) • pH Metabolic acidosis (pH < 7.3) • Blood Ketones Ketonaemia • ABGs  Hypocapnic (‘blow off’ CO2) • Base Excess • Bicarbonate (low) • U and Es Sodium and Potassium • FBC

9. Plus other investigations IF INDICATED! • CXR • CSF • Throat swab • Blood culture • Urinalysis NB. DKA may rarely be precipitated by sepsis, and fever is not part of DKA!

10. Observations • Strict fluid balance. • Urine output for every sample; test for ketones. • Hourly BP and basic obs. • Capillary ketones if available – more sensitive. • Hourly capillary blood glucose • Twice daily weight (fluid balance). • Hourly or more freq neuro obs initially. • Report any changes in conscious level, behaviour, ECG or onset of headache.

11. Management 1: Fluids • Vol of fluid Requirement = Maintenance + Deficit Deficit (litres) = %dehydration x body weight (convert to ml) No more than 10%

12. Maintenance requirements Age 0-2 years 80 ml/kg/24 hrs 3-5 70 ml/kg/24 hrs 6-9 60 ml/kg/24 hrs 10-14 50 ml/kg/24 hrs >15 30 ml/kg/24 hrs

13. Add calculated maintenance (for 48 hrs) and estimated deficit, subtract the amount already given as resuscitation fluid, and give the total vol evenly over the next 48 hrs, i.e. Hourly = 48 hr maint + deficit – resus fluid rate 48

14. Example: A 20 kg 6-yr-old boy who is 10% dehydrated, and who has already had 20 ml/kg saline, will require: • 10% x 20 kg = 2000 mls deficit • Plus 60 ml x 20 kg = 1200 mls maitenence/24h = 2400 mls over 48h • Maintenance + deficit = 4400 mls over 48h • Minus 20kg x 20ml = 400 mls resus fluid = 4000 mls over 48h = 83 mls/hr!! NB. Do not include continuing urinary losses in your calculations.

15. Type of Fluid: • Initially use 0.9% saline. • Once blood glucose  to 14-17 mmol/L, add glucose. • If this occurs in first 6 hrs  discuss with senior. • After 6 hrs  0.45% saline/5% dextrose. • Oral Fluids: • None in severe dehydration, impaired consciousness and acidosis. • Only offered after substantial clinical improvement and no vomiting. • Need for IV infusions to be reduced.

16. 2. Potassium • Once resus complete, commence immediately. • Always a massive depletion of total body K+, even if low to start with, because of insulin. • Initially add 20 mmol KCl to every 500ml bag of fluid (40mmol/L). • Check U&Es 2h after resus, then at least 4 hourly. Adjust K+ replacements accordingly. • ECG  observe for T wave changes.

17. 3. Insulin • Essential to switch off ketogenesis and reverse the acidosis. • Continuous low-dose IV infusion. • Run at 0.1 U/kg/hr  maintain at this rate. • If rate of glucose fall exceeds 5 mmol/L/hr, or falls to ~14-17mmol/L, add dextrose (5-10%) to IV fluids. • Once pH > 7.3, BM 14-17, and dextrose-containing fluid commenced, consider  insulin rate, but to no less than 0.5 U/kg/hr.

18. 4. Bicarbonate • Virtually never necessary. • Always consult senior before administering. • Only purpose is to improve cardiac contractility in severe shock.

19. 5. Phosphate • Always a depletion. • No evidence in adults or children that replacement has any clinical benefit and phosphate administration may lead to hypocalcaemia.

20. Cerebral Oedema • Unpredictable. • More freq in younger children with newly diagnosed diabetes. • Mortality ~ 25%. • Unknown cause. • Aim of DKA therapy  slow correction of metabolic abnormalities -  incidence of cerebral oedema.

21. Signs and Symptoms • Headache and slowing of HR. • Change in neuro status (restlessness, irritability, increased drowsiness, incontinence) • Specific neuro signs (e.g. cranial nerve palsies) • Rising BP, decreasing O2 saturation • Abnormal posturing • More dramatic changes  convulsions, papilloedema, resp arrest  late signs assoc with extremely poor prognosis.

22. Management • If suspected – inform senior staff immediately • Exclude hypoglycaemia • Give Mannitol 1 g/kg stat (= 5ml/kg Mannitol 20% over 20 mins) or hypotonic saline (5-10mls/kg over 30 mins) ASAP!!! • Restrict IV fluids to 2/3 maintenance and replace deficit over 72 rather than 48 hrs. • PICU. • CT  exclude other diagnoses. • Repeat dose of Mannitol after 2h if no response.

23. Other Complications • Hypoglycaemia and Hypokalaemia  avoid by careful monitoring and adjustment of infusion rates. • Systemic Infections  Abx not given routinely unless severe bacterial infection suspected. • Aspiration Pneumonia  Avoid by NG tube in vomiting child with impaired consciousness