Clinical Guidelines (Nursing)

Ketogenic diet acute illness management

  • Introduction 

    Aim

    Definition of Terms

    Assessment

    Management of dehydration

    Management of excessive ketosis

    Links 

    Evidence Table

    References


    Introduction

    The Ketogenic Diets (KD) are a recognised treatment option for some children with refractory epilepsy and Glucose transporter 1 deficiency syndrome (Glut 1 DS).  The Royal Children’s Hospital offers two types of ketogenic diet: the classical or modified Atkins diet (MAD). The KD diet has some potential side effects, but is generally well tolerated. Many childhood illnesses can be managed at home.

    When a child on a KD becomes unwell and presents to hospital, the illness and its effect on the diet requires assessment.  Children on a KD will usually require hospital review if they present with the following: 

    • vomiting and diarrhoea (often caused by gastroenteritis),
    • febrile illness,
    • increased seizures.

    Aim

    The aim of this guideline is to provide a medical, nursing and allied health framework for decision making in relation to the management of the unwell child on KD therapy. 

    Definition of terms 

    • Ketogenic Diet (KD): Are very high fat, low carbohydrate, medically supervised diets often used as a treatment option for some children with refractory epilepsy and Glut1DS.  The diet is calculated for each child on an individual basis and so dietary prescriptions for fat, protein and carbohydrate are specific for each child.
    • Ketone bodies: Are water-soluble compounds that are produced when excessive amounts of fat are broken down for energy.  In some circumstances they are used as a source of energy in the heart and brain.   

    Assessment 

    There are four key factors to the assessment of a child on KD therapy who is acutely unwell presenting to hospital for management.  

    1)    Establish child’s medical status

    • What is causing the child to be unwell? 
    • Note: Any child who is septic, vomiting blood or bile or has severe abdominal pain needs IMMEDIATE assessment by a senior paediatric medical member. 

    2)   Establish patient’s level of hydration

    • Assess degree of dehydration on clinical signs and change in body weight (if recent weight available) as per RCH Dehydration guidelines. 
    • Mild dehydration (< 4%) no clinical signs. They may have increased thirst.
    • Moderate dehydration (4-6%) delayed CRT (capillary refill time) >2 secs, increased respiratory rate, mild decreased skin turgor
    • Severely dehydrated (>/=7%) very delayed CRT >3 seconds, mottled skin, decreased skin turgor, signs of shock-tachycardia, reduced conscious state or irritable, hypotension, deep acidotic breathing.

    3)  Establish if patient has excessive ketosis

    • Take capillary gases, electrolytes, calcium, magnesium, phosphate, urea and glucose   
    • Clinical signs of excessive ketosis
      • excessive fatigue or lethargy,
      • nausea,
      • vomiting, 
      • very strong fruity smell on breath, 
      • rapid panting/breathing, 
      • an increased heart rate.

    4)  Establish if patient has experienced change in usual level of ketosis 

    • Measure serum ketone level (beta-hydroxybutyrate) by finger prick: usually maintained between 2.4-5mmol/L. 
    • Measure urine ketone level if possible (Ketodiastix®): usually maintained between 8-16mmol/L.  (Parents/caregivers may report Ketodiastix® has turned instantly black if level is too high).
    • Note that serum ketone levels above 5mmol/L are not necessarily concerning provided the child is not demonstrating clinical signs of excessive ketosis.
    • Lower than usual levels of ketones are not dangerous.
    • Families usually have a routine for measuring ketones when a child is well and will be able to report any changes.

    Management of  dehydration 

    https://www.rch.org.au/clinicalguide/guideline_index/Dehydration/

    Oral Rehydration

    • Increase frequency of usual KD fluids (These may include water, Ketocal® in correct ratio and others, check with dietitian if suitable fluids are being provided). 
    • No regular soft drinks, milk, cordial, juices or icypoles are allowed. 
    • Oral rehydration solutions may be used, these include Repalyte® (1.8gm glucose/100ml) and Hydralyte® (1.5gm glucose/100ml).  Consider using Hydralyte® icypoles.
    • Rehydration is more important than any loss of ketosis the child may experience.
    • Strict fluid balance documentation in flow sheets in EPIC 

    Nasogastric rehydration

    • Used to rehydrate most children with moderate to severe dehydration.  In many cases it may be used when the child continues to vomit.  Replace deficit over 6 hours, give daily maintenance over the next 18 hours.  To calculate the hourly rate see recommended as per “RCH Gastroenteritis guidelines”.Suitable fluids may include: Hydralyte®, Repalyte® and ketogenic diet fluids in the child’s correct prescribed ratio as advised by a paediatric dietitian such as Ketocal®. 
    • Strict fluid balance documentation in flow sheets in EPIC 

    Intravenous rehydration 

    • Any child with severe dehydration may require immediate boluses of normal saline (10-20ml/kg) and then maintenance fluids adjusted according to clinical situation.
    • No IV glucose should be given (provided true BSL ≥2.6mmol/L) unless ordered by the on-call Neurology Consultant.
    • Strict fluid balance documentation in flow sheets in EPIC 
    • Urgent investigations:
      • Urea & electrolytes
      • glucose
      • FBE
      • Capillary blood gas
      • Urinalysis
    • Consider need for septic work up or surgical consult.

    Contact General Medical Consultant:

    • if patient haemodynamically unstable, 
    • if has a past history of gut surgery,
    • if has a past history of other significant disease,
    • if electrolyte abnormalities.

    Management of excessive ketosis

    Excessive ketoacidosis needs to be managed by the administration of extra carbohydrate.  

    Orally, Nasogastrically 

    • Administer child 30ml regular lemonade/apple or orange juice  
    • Retest serum ketones using finger prick 15 minutes after administration. 
    • If serum ketone level ≥6mmol/L and/or patient showing clinical symptoms of excessive ketosis, administer another 30ml regular lemonade and monitor clinical symptoms. 
    • If second dose of regular lemonade does not result in improvement the child may require IV glucose bolus or maintenance. 
    • Serum ketones will need to be monitored 6 hourly whilst ketone levels are high or unstable. 
    • Blood glucose levels will need to be monitored at the same time as blood ketone levels or as clinically indicated. Aim for ≥2.6mmol/L. Contact Neurology Consultant before any treatment.

    Intravenously 

    If ongoing  excessive ketosis a child may require management with IV a Maintenance 5% Dextrose and Normal Saline  or IV bolus.
    Note: an IV bolus of (30mls of 10% glucose is equivalent to 30mls lemonade/juice) and may be utilised if clinically appropriate.

    General Guidelines 

    • Medications should be in tablet form as syrups contain sweeteners or sugars that are not compatible with a ketogenic diet.
    • Excessive ketosis and well – no concern.
    • Excessive ketosis & drowsy – assess for other medical factors contributing and if no contributing medical factor then maintenance 5% Dextrose & Normal Saline.
    • Excessive ketosis & hypoglycaemia – follow hypoglycaemia protocol.

    Contact General Medical or Endocrinology Consultant if high ketosis and child unwell.

    Links

    Evidence table

    Please remember to read the disclaimer. 

    References

    1. Thammongkol et al. (2012) Efficacy of the ketogenic diet: Which epilepsies respond? Epilepsia, 53(3):e55–e59.
    2. Kossoff et al. (2018) Optimal clinical management of children receiving dietary therapies: Updates recommendations of the International Ketogenic Diet Study Group. Epilepsia 3(2):175-192
    3. Neal et all. (2008) The ketogenic diet for the treatment of childhood epilepsy: a randomised controlled trial. Lancet Neurol 7:500–506.
    4. Clinical Practice Guidelines; Royal Children’s Hospital (2018) Dehydration, Gastroenteritis,Intravenous therapy and hypoglycaemia Melbourne, Australia.
    5. Kossoff EH, Turner Z, Doerrer SC et al. (2016) The ketogenic and modified Atkins diet: Treatments for Epilepsy and Other Disorders. Sixth Edition  New York: Demos Health
    6. Kang HC, Chung DE, Kim DW (2004) Early and late-onset complications of the Ketogenic Diet for Intractable Epilepsy. Epilepsia, 45(9):1116-1123

    The development of this nursing guideline was coordinated by Jill Bicknell-Royle, Epilepsy Nurse Coordinator, Department of Neurology, and approved by the Nursing Clinical Effectiveness Committee. Updated March 2019.