Paediatric Diabetic Ketoacidosis

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

Management 1) Emergency management  ABC!! 1. Airway  ensure it’s patent. If comatose, insert an airway. Recurrent vomiting – NG tube, aspirate, leave to open drainage. 2. Breathing  100% O 2 by face mask. 3. Circulation  insert IV cannula and take blood samples. ECG for T waves (hyperkalaemia)

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.

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

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

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

Initial Investigations– What should be checked and what they may show! Blood Glucose  Hyperglycaemia (BM > 11mml/L) Blood Glucose  Hyperglycaemia (BM > 11mml/L) pH  Metabolic acidosis (pH < 7.3) pH  Metabolic acidosis (pH < 7.3) Blood Ketones  Ketonaemia Blood Ketones  Ketonaemia ABGs  Hypocapnic (‘blow off’ CO 2 ) ABGs  Hypocapnic (‘blow off’ CO 2 ) Base Excess Base Excess Bicarbonate (low) Bicarbonate (low) U and Es  Sodium and Potassium U and Es  Sodium and Potassium FBC FBC

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

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

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

Maintenance requirements Maintenance requirements Age 0-2 years 80 ml/kg/24 hrs ml/kg/24 hrs ml/kg/24 hrs ml/kg/24 hrs ml/kg/24 hrs ml/kg/24 hrs ml/kg/24 hrs >15 30 ml/kg/24 hrs >15 30 ml/kg/24 hrs

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 rate 48

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 10% x 20 kg = 2000 mls deficit Plus 60 ml x 20 kg = 1200 mls maitenence/24h Plus 60 ml x 20 kg = 1200 mls maitenence/24h = 2400 mls over 48h = 2400 mls over 48h Maintenance + deficit = 4400 mls over 48h Maintenance + deficit = 4400 mls over 48h Minus 20kg x 20ml = 400 mls resus fluid 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.

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

2. Potassium Once resus complete, commence immediately. Once resus complete, commence immediately. Always a massive depletion of total body K +, even if low to start with, because of insulin. 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). 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. Check U&Es 2h after resus, then at least 4 hourly. Adjust K+ replacements accordingly. ECG  observe for T wave changes. ECG  observe for T wave changes.

3. Insulin Essential to switch off ketogenesis and reverse the acidosis. Essential to switch off ketogenesis and reverse the acidosis. Continuous low-dose IV infusion. Continuous low-dose IV infusion. Run at 0.1 U/kg/hr  maintain at this rate. 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. 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. 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.

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

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

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

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

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

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