University Hospital of Wales Paediatric Intensive Care Unit Guideline Printed on Wed 23-jul-08
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Last updated March 21, 2013 8:29 AM

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University Hospital of Wales Heath Park
Cardiff
CF14 4XW
02920 747747

Diabetic ketoacidosis


We use the DKA guidlines that the paediatric endocrinology department have produced, and these are the same as the British Society of Paediatric Endocrinology guidelines. These have been recently updated.

New BSPED DKA Guidelines 2009

BSPED DKA Calculator

BSPED DKA Flowchart

The main changes in the new documents are as follows:
1. Recommendation to use capillary blood ketone measurement during treatment. This is not currently routinely available at UHW, but may became available in the future.
2. Reduction in the degree of dehydration to be used to calculate fluids
3. Reduction in maintenance fluid rates
4. Change in the recommendations for PICU/HDU - more emphasis on safe nursing on general wards
5. Continuation of Normal saline for the first 12 hours of rehydration
6. Delay in insulin until fluids have been running for an hour
7. Option to continue insulin glargine during treatment
8. Reminder to stop insulin pump therapy during treatment
9. Reminder to consider anticoagulant prophylaxis in young children, especially those with femoral lines
10. Interpretation of blood ketone measurements if pH not improving
11. Option to use hypertonic saline instead of mannitol for the treatment of cerebral oedema

The Department of Child Health also uses an Integrated Care Pathway for children with DKA on the general wards and HDU. It is not used on PICU.

Background

It is unusual for children with DKA to come to PICU - they are usually looked after in their local hospital or in HDU at UHW. Some of the guidance below is intended more for patients outside PICU

Other aspects of diabetes management are available on the intranet site - only accessible from trust computers - navigate the clinical portal to: child health>paediatric diabetes>clinical guidance

General principles

General considerations

These are general guidelines for management. Treatment may need modification to suit the individual patient and these guidelines do not remove the need for frequent detailed reassessments of the individual child's requirements.
These guidelines are intended for the management of the children who have:
- Hyperglycaemia (BG >11mmol/l)
- pH < 7.3
- Bicarbonate <15mmol/l
and who are:
- more than 3% dehydrated
- and/or vomiting
- and/or drowsy
- and/or clinically acidotic

Children who are 5% dehydrated or less and not clinically unwell usually tolerate oral rehydration and subcutaneous insulin. Discuss this with the senior doctor on call.
Please discuss with the duty Consultant for Paediatric Endocrinology and Diabetes (available through switchboard) if you admit anyone in DKA, either at night if there are problems with management, or the next morning
(bleep the endocrine SpR during the day, or Extn 2274/6374 (consultant secretaries), or mobile phone no 07778142746 out of hours).
If the child is ill (and certainly if the child is admitted to ITU), please inform the duty Endocrine and Diabetes Consultant.

Emergency management

1. General Resuscitation: A, B, C.
Airway:
- Ensure that the airway is patent and if the child is comatose, insert an airway.
- If comatose or recurrent vomiting, insert N/G tube, aspirate and leave on open drainage.
Breathing:
- Give 100% oxygen.
Circulation:
- Insert IV cannula and take blood samples (see below).
- If shocked (poor peripheral pulses, with poor capillary filling with tachycardia, and/or hypotension) give 10 ml/kg 0.9% saline as a bolus, and repeat as necessary to a maximum of 30mls/kg (there is no evidence to support the use of colloids or other volume expanders in preference to crystalloids).
2. Confirm the Diagnosis (if a new patient):
History:
- polydipsia, polyuria
Clinical:
- acidotic respiration
- dehydration
- drowsiness
- abdominal pain/vomiting
Biochemical:
- high blood glucose on finger-prick test
- glucose in urine and ketones in blood and urine.

Near patient blood ketone monitors may be available from Diabaetic Liaison Nurses Extension 5435, but are not currently part of local management in UHW.


3. Initial Investigations:
- WEIGH THE CHILD: If this is not possible because of the clinical condition, use the most recent clinic weight as a guideline or an estimated weight from centile charts.
- blood glucose
- urea and electrolytes (electrolytes on blood gas machine give a guide until accurate results available
- blood gases (preferably arterial or capillary, but venous gives similar pH)
- PCV and full blood count

Other investigations only if indicated e.g. CXR, CSF, throat swab, blood cultures, urinalysis, culture and sensitivity etc.
(DKA may rarely be precipitated by sepsis, and fever is not part of DKA)

Clinical assessment and observations

Assess and record in the notes, so that comparisons can be made by others later.
1. Degree of Dehydration -
- 3% dehydration is only just clinically detectable
- mild, (5%) - dry mucous membranes, reduced skin turgor
- moderate (7.5%) - above with sunken eyes, poor capillary return
- severe, (10% ± shock) - severely ill with poor perfusion, thready rapid pulse, (reduced blood pressure is not likely and is a very late sign).
2. Conscious Level -
- Institute hourly neurological observations whether or not drowsy on admission.
- If in coma on admission, or there is any subsequent deterioration:
- record Glasgow Coma Score (see Appendix)
- transfer to ICU
- consider instituting cerebral oedema management (section F)
3. Full Examination - looking particularly for evidence of:
o cerebral oedema: headache, irritability, slowing pulse, rising blood pressure, reducing conscious level
o infection
o ileus
4. Does the child need to be on ICU? -
YES if:
- intubated
Intubating and ventilating children with DKA is difficult and carries a significant risk of making things worse - if there is time to discuss the patient with PICU prior to intubation, please do so.
5. Observations to be carried out:
Ensure full instructions are given to the senior nursing staff emphasising the need for:
- strict fluid balance and urine testing for ketones of every sample
- hourly BP and basic observations
- capillary blood ketone levels may be available and may be a sensitive measure of suppression of ketogenesis during treatment
- hourly capillary blood glucose measurements (these may be inaccurate with severe dehydration/acidosis but useful in documenting trends. Do not rely on any sudden changes but check with a venous laboratory glucose measurement)
- twice daily weights can be helpful in assessing fluid balance
- hourly or more frequent neuro observations initially
- reporting immediately to the medical staff, even at night, symptoms of headache or any change in either conscious level or behaviour
- reporting any changes in the ECG trace, especially T wave changes

Specific management guidelines

  • Fluids
  • Potassium
  • Insulin
  • Phosphate
  • Bicarbonate
  • Cerebral Oedema

It is essential that all fluids given are documented carefully, particularly the fluid which is given in Casualty and on the way to the ward, as this is where most mistakes occur.

a) Volume of fluid
By this stage, the circulating volume should have been restored. If not, give a further 10 ml/kg 0.9% saline (to a maximum of 30mls/kg) over 30 minutes. (Discuss with a consultant if the child has already received 30mls/kg).
Otherwise, once circulating blood volume has been restored, calculate fluid requirements as follows

Requirement = Maintenance + Deficit
Deficit (litres) = % dehydration x body weight (kg)/100

To avoid overzealous fluid replacement never use more than 10% dehydration in the calculations.

Maintenance values

Weight (kg) ml/kg/24hours
0 - 12.9 80
13 - 19.9 65
20 - 34.9 55
35 - 59.9 45
>60; adult 35

Add the calculated maintenance (for 48 hours) and estimated deficit together, subtract the amount already given as resuscitation fluid, and give total volume evenly over the next 48 hours.
i.e. Hourly rate = (48 hour maintenance + deficit – resuscitation fluid already given) / 48

Example:
A 20 kg 6 year old boy who is 8% dehydrated, and who has already had 20ml/kg saline, will require

8 % x 20 kg = 1600 mls deficit
plus 55ml x 20kg = 1100 mls maintenance first 24 hours
plus 55ml x 20kg = 1100 mls maintenance second 24 hours
= 3800 mls
minus 20kg x 20ml = 400 mls resus fluid
3400 mls over 48 hours = 71 mls/hour

Do not include continuing urinary losses in the calculations at this stage

b) Type of fluid
Initially use 0.9% saline with 20 mmol KCl in 500 ml, and continue this sodium concentration for at least 12 hours.

Once the blood glucose has fallen to 14 mmol/l add glucose to the fluid.

A bag of 500 ml 0.9% saline with 5% glucose and 20 mmol KCl should be available from Pharmacy (it can be obtained as an unlicensed bag from Baxter- Code FKB2486). If not, make up a solution as follows - withdraw 50ml 0.9% sodium chloride/KCl from 500ml bag, and add 50ml of 50% glucose (this makes a solution which is approximately 5% glucose with 0.9% saline with potassium).

After 12 hours, if the plasma sodium level is stable or increasing, change to 500ml bags of 0.45% saline/5% glucose/20 mmol KCl.

If the plasma sodium is falling, continue with Normal saline (with or without glucose depending on blood glucose levels). Some have suggested that Corrected Sodium levels give an indication of the risk of cerebral oedema. If you wish to calculate this, go to:

http://www.strs.nhs.uk/resources/pdf/guidelines/correctedNA.pdf.

Corrected sodium levels should rise as blood glucose levels fall during treatment. If they do not, then continue with Normal saline and do not change to 0.45% saline.
Check U & E's 2 hours after resuscitation is begun and then at least 4 hourly
Electrolytes on blood gas machine can be helpful for trends whilst awaiting laboratory results.
The following solutions should soon be available from pharmacies:
500ml bag of 0.45% saline / 5% glucose containing 20 mmol KCl
500ml bag of 0.9% saline / 5% glucose containing 20 mmol KCl

c) Oral fluids
In severe dehydration, impaired consciousness & acidosis do not allow fluids by mouth. A N/G tube may be necessary in the case of gastric paresis.

Oral fluids (eg fruit juice/oral rehydration solution) should only be offered after substantial clinical improvement and no vomiting

When good clinical improvement occurs before the 48hr rehydration period is completed, oral intake may proceed and the need for IV infusions reduced to take account of the oral intake.

Once the child has been resuscitated, potassium should be commenced immediately with rehydration fluid unless anuria is suspected. Potassium is mainly an intracellular ion, and there is always massive depletion of total body potassium although initial plasma levels may be low, normal or even high. Levels in the blood will fall once insulin is commenced.


Therefore add 20 mmol KCl to every 500 ml bag of fluid (40 mmol per litre).

Check U & E's 2 hours after resuscitation is begun and then at least 4 hourly, and alter potassium replacements accordingly. If standard bags are not available, strong potassium solution will need to be added, but always check with another person.

Use a cardiac monitor and observe frequently for T wave changes.

Once rehydration fluids and potassium are running, blood glucose levels will start to fall. There is some evidence that cerebral oedema is more likely if insulin is started early. Therefore DO NOT start insulin until intravenous fluids have been running for at least an hour.

Continuous low-dose intravenous infusion is the preferred method. There is no need for an initial bolus.

Make up a solution of 1 unit per ml. of human soluble insulin (e.g. Actrapid) by adding 50 units (0.5 ml) insulin to 50 ml 0.9% saline in a syringe pump. Attach this using a Y-connector to the IV fluids already running. Do not add insulin directly to the fluid bags.
The solution should then run at 0.1 units/kg/hour (0.1ml/kg/hour). There are some paediatricians who believe that 0.05 units/kg/hour is an adequate dose. There is no firm evidence to support this.

Once the blood glucose level falls to 14mmol/l, change the fluid to contain 5% glucose (generally 0.9% saline with glucose and potassium, see 1b above for type of fluid). DO NOT reduce the insulin. The insulin dose needs to be maintained at 0.1 units/kg/hour to switch off ketogenesis.

Some suggest also adding glucose if the initial rate of fall of blood glucose is greater than 5-8 mmol/l per hour, to help protect against cerebral oedema. There is no good evidence for this practice, and blood glucose levels will often fall quickly purely because of rehydration.

DO NOT stop the insulin infusion while glucose is being infused, as insulin is required to switch off ketone production. If the blood glucose falls below 4 mmol/l, give a bolus of 2 ml/kg of 10% glucose and increase the glucose concentration of the infusion. Insulin can temporarily be reduced for 1 hour.

If needed, a solution of 10% glucose with 0.45% saline can be made up by adding 50ml 50% glucose to a 500 ml bag of 0.45% saline/5% glucose with 20 mmol KCl.Once the pH is above 7.3, the blood glucose is down to 14 mmol/l, and a glucose-containing fluid has been started, consider reducing the insulin infusion rate, but to no less than 0.05 units/kg/hour.

If the blood glucose rises out of control, or the pH level is not improving after 4-6 hours consult senior medical staff and re-evaluate (possible sepsis, insulin errors or other condition), and consider starting the whole protocol again.

For children who are already on long-acting insulin (especially Glargine (Lantus)), your local consultant may want this to continue at the usual dose and time throughout the DKA treatment, in addition to the IV insulin infusion, in order to shorten length of stay after recovery from DKA.

For children on continuous subcutaneous insulin infusion (CSII) pump therapy, stop the pump when starting DKA treatment.

There is always depletion of phosphate, another predominantly intracellular ion. Plasma levels may be very low. There is no evidence in adults or children that replacement has any clinical benefit and phosphate administration may lead to hypocalcaemia.
This is rarely, if ever, necessary. Continuing acidosis usually means insufficient resuscitation or insufficient insulin. Bicarbonate should only be considered in children who are profoundly acidotic (pH< 6.9) and shocked with circulatory failure. Its only purpose is to improve cardiac contractility in severe shock.
Before starting bicarbonate, discuss with senior staff, and the quantity should be decided by the paediatric resuscitation team or consultant on-call.

The signs and symptoms of cerebral oedema include:

  • headache & slowing of heart rate
  • change in neurological status (restlessness, irritability, increased drowsiness, incontinence)
  • specific neurological signs (eg. cranial nerve palsies)
  • rising BP, decreased O2 saturation
  • abnormal posturing

More dramatic changes such as convulsions, papilloedema, respiratory arrest are late signs associated with extremely poor prognosis


Management :

If cerebral oedema is suspected inform senior staff immediately.
The following measures should be taken immediately while arranging transfer to PICU–

  • exclude hypoglycaemia as a possible cause of any behaviour change
  • give hypertonic (2.7%) saline (5mls/kg over 5-10 mins) or Mannitol 0.5 – 1.0 g/kg stat (= 2.5 - 5 ml/kg Mannitol 20% over 20 minutes). This needs to be given as soon as possible if warning signs occur (eg headache or pulse slowing).
  • restrict IV fluids to 1/2 maintenance and replace deficit over 72 rather than 48 hours
  • the child will need to be moved to PICU (if not there already)
  • discuss with PICU consultant. Do not intubate and ventilate until an experienced doctor is available
  • once the child is stable, exclude other diagnoses by CT scan - other intracerebral events may occur (thrombosis, haemorrhage or infarction) and present similarly
  • a repeated dose of Mannitol may be required after 2 hours if no response
    document all events (with dates and times) very carefully in medical records



 

Anticoagulation

There is a significant risk of femoral vein thrombosis in young and very sick children with DKA who have femoral lines inserted. Therefore consideration should be given to anticoagulating these children with 100 units/kg/day as a single daily dose of Fragmin.
Children who are significantly hyperosmolar might also require anticoagulant prophylaxis (discuss with consultant).

Continuing management

Urinary catheterisation should be avoided but may be useful in the child with impaired consciousness.

Documentation of fluid balance is of paramount importance. All urine needs to be measured accurately (and tested for ketones if blood ketones are not being monitored). All fluid input must be recorded (even oral fluids).

If a massive diuresis continues fluid input may need to be increased. If large volumes of gastric aspirate continue, these will need to be replaced with 0.45% saline with KCl.
Check biochemistry, blood pH, and laboratory blood glucose 2 hours after the start of resuscitation, and then at least 4 hourly. Review the fluid composition and rate according to each set of electrolyte results.


If acidosis is not correcting, consider the following