Ketogenic diet: inpatient and illness protocol

Occasionally ketone levels can become too high. This may occur after starting the diet or during illness.

Signs and Symptoms:

Rapid panting breathing, increased heart rate, facial flushing, irritability, vomiting and unexpected lethargy. Excess ketosis may also mimic non convulsive status as the children are often less responsive.

Confirming Hyperketosis:

1. Check the urinary ketones using Ketostix-
   • A high level of urinary ketones (acetoacetate) may show 16+ and change to a deep purple straight away.
2. Check blood ketones using a portable blood ketone monitor (many parents will have this).
   • A high level of blood ketones is > 6 mmol/L.
3. Confirm by sending sample to lab – betahydroxybutyrate, a high level is >6 mmol/L.

Management:

1. To treat give 30ml of pure fruit juice (orange juice) or 30mls water with 5g Maxijul which can be obtained from the Special Feeds Unit
2. After 15-20 minutes recheck ketones, if persistently high or symptoms persist the above treatment may need to be repeated.
3. It may be necessary to alter the diet ratio if ketone levels are persistently excessive and the child is symptomatic (liaise with the dietitian).

All children on the ketogenic diet will have a lower serum bicarbonate as an expected consequence of the diet.  We would not normally expect children to have a significant metabolic acidosis (low pH).  

Patients at Risk: 

1. A patient who is taking Topiramate, Zonisamide or Acetozalomide.
2. Patients with renal impairment

Symptoms:

Increased seizures, clamminess and pale skin, confusion, in severe forms- ‘Kussmaul’ breathing (increased rate and depth of breathing) 

Management:

1. Check electrolytes, bicarbonate, urinary ketones, blood ketones (betahydroxybutyrate) and blood gas.
2. If hyperketotic follow the pathway for hyperketosis as above.
3. Ensure adequate hydration with water or sugar free oral fluids
4. If IV fluids need to be given use normal saline (0.9% NaCl).
5. Diet manipulation (to be initiated by dietitian): consider increasing daily caloric intake or reducing the ratio of the diet.
6. Consider reduction/withdrawal of the Topiramate, Zonisamide or Acetozalomide with the ketogenic diet team.

Check blood sample/ lab sugar and treat if appropriate as below

Management of symptomatic hypoglycaemia

Treating hypoglycaemia using rapidly absorbed carbohydrate Use one of the following:

• 50ml of Cola/Iron Bru drink (NOT DIET)
• 50ml of pure fruit juice
• 1tsp of sugar mixed into 50mls water
• 5g (1 level teaspoon) Dextrose powder in 50mls water. Dextrose available from Pharmacy
• 5g Maxijul in 30ml water. Maxijul available from Special Feeds Unit

If the response is inadequate, more can be administered after 10-15 minutes

Treating hypoglycaemia using Glucogel (formerly known as Hypostop)

Give Glucogel (formerly known as Hypostop) 
½  of a 25g tube = 5g carbohydrate

This can be squeezed into the child’s mouth if the child is uncooperative, or not able to take the items suggested above (child must be allowed to have foods orally)

If IV fluids are required

Severe symptomatic hypoglycaemia should be treated as per APLS Guidelines with 2mls/kg of 10% dextrose followed by infusion of 2.5% or 5% dextrose.

1. As soon as possible after admission, contact medical and KD team (see end of document) and on-call neurologist

2. Test urine for ketones every time child passes urine

3. Daily weights

4. Check BMs/glucostix 2 – 4 hourly if children are unwell, especially if nil by mouth (note that if the child is ketotic, blood glucose may be low but still acceptable, i.e. 3 mmol if the child is not symptomatic)

5. Start clear fluids (low carbohydrate and protein free), e.g. water or sugar free squash. Dioralyte can also be used if necessary.

6. With the guidance of a dietitian, after 24 hours reintroduce diet at ½ portions given more frequently throughout the day. If well tolerated gradually build up to full meals. Most children will have been given a ketogenic emergency drink recipe; this may be a useful alternative to solid food and can be diluted if necessary.

7. Where possible avoid sugar and carbohydrate containing drugs. If IV fluids are required use normal saline (0.9% NaCl) or if BM’s < 3mmol/l use 2.5% dextrose/saline solution.
   
   If you are unsure of the carbohydrate content of medications, you should contact the ward pharmacist or medicines information.  

6. Urgent bloods if child is unwell:
   
   FBC, renal function, bicarbonate, liver function, lactate, blood gas, urinary ketones (using Ketostix), blood ketones
   Infection screen as indicated 

7. Emergency management of symptomatic hypoglycaemia or BMs <3mmol
   Please check true blood glucose (lab) and give emergency treatment
   (see management guidelines for symptomatic hypoglycaemia for further information).

8. Rehydrate with clear fluids if tolerated orally – water, sugar-free squash. As soon as possible, reintroduce ketogenic diet (liaise with the dietitian for advice).

The high fat diet regimen of the ketogenic diet (70-90% of calories) forces the body into a dietary induced ketosis. The acidosis that occurs when the diet is first initiated corrects itself within days and is not sustained.

The literature on the ketogenic diet and GA is scarce, with very little consensus on management.  The most comprehensive study undertaken so far suggests that carbohydratefree solutions are safe and blood glucose remains stable throughout surgical procedures up to 11.5 hours. The most common effect noted in procedures > 3 hours was a significant decrease in pH, requiring IV bicarbonate. Current advice suggest therefore monitoring blood pH in procedures > 3 hours and administering IV Bicarbonate where necessary.  (Valencia et al, 2002; Epilepsia; vol 43, issue 5; p525)

1. Inform KD team about admission of patient, see end of document
   
   
2. Test blood or urine ketones every 4-6 hours
   
   
3. Take bloods: FBC, renal function, bicarbonate, liver function, urinalysis, blood gas, glucose, lactate, blood ketones
   
   
4. General anaesthetic : Keep NBM for normal recommended time period (6 hours food / clear fluids 2 hours).
   
   
5. If IV fluids are required give normal saline (0.9% NaCl) or Ringers lactate at appropriate rate.
   
   
6. If anaesthetic is > 3 hours monitor BM’s and blood gas (pH and bicarbonate) Consider IV bicarbonate if increase in acidosis.
   
   
7. If fasting beyond 12 hours or BMs < 3 mmol/L use dextrose containing solutions (i.e. 2.5% or 5%) to maintain BMs above 3 mmol/L.

8. Continue IV normal saline until oral fluids tolerated.
   
   
9. Re-introduce normal (ketogenic) diet as soon as possible. Please contact KD dietitian to discuss a suitable diet, or if nasogastric tube or gastrostomy are required, the type of formula to be given.

Where possible, avoid sugar and carbohydrate containing drugs and IV solutions.  If you are unsure of the carbohydrate content of medications, you should contact the ward pharmacist, or contact medicines information.  If in doubt, substances ending in “ose” or “ol” are usually converted to glucose in the body (cellulose is an exception and is suitable).