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Sedation for diagnostic and therapeutic procedures on children with cardiac conditions on Ward 1E

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The aim of sedation guideline is to provide evidence-based approach to the sedation of the cardiac patients on the cardiac ward during diagnostic or therapeutic procedures. This guideline is adapted from the NICE clinical guideline, Sedation in under 19s: using sedation for diagnostic and therapeutic procedures (CG112, last reviewed 2018).


This guideline is intended for all healthcare professionals caring for children on the cardiac ward 1E at the Royal Hospital for Children, Glasgow.


All medical and nursing staff caring for patients requiring sedation should be familiar with the guideline and have theoretical knowledge of the principles of sedation practice including the drug pharmacology and applied physiology. 


Sedation is performed on patients to reduce fear, anxiety and to minimize movement. On the cardiac ward sedation is often required for children going to theatre, echocardiogram or removal of chest drain. This guideline is based on the NICE recommendations and can be used for children and young people under the age of 19 undergoing diagnostic or therapeutic procedures. The level of sedation used on patients on the ward setting should be minimal to moderate and conducted within hours of 8 am till 6 pm. Deep sedation should be avoided.

Levels of sedation:

The definitions of minimal, moderate and deep sedation used in this guideline are based on those of the American Society of Anaesthesiologists (ASA).

Minimal sedation: A drug induced state during which patients are awake and calm, and respond normally to verbal commands. Although cognitive function and coordination may be impaired, ventilatory and cardiovascular functions are unaffected.

Moderate Sedation: Drug induced depression of consciousness during which patients are sleepy but respond purposefully to verbal commands or light tactile stimulation. No interventions are required to maintain a patent airway. Spontaneous ventilation is adequate. Cardiovascular function is maintained.

Deep sedation: Drug- induced depression of consciousness during which patients are asleep and cannot be easily roused but do respond purposefully to repeated or painful stimulation. The ability to maintain ventilatory function independently may be impaired. Patients may require assistance to maintain a patent airway. Spontaneous ventilation may be inadequate. Cardiovascular function is usually maintained. 

Pre sedation

Pre sedation assessment, communication and patient information and consent

Health care professionals delivering sedation should have knowledge and understanding of and competency in:

  • Sedation pharmacology and applied physiology
  • Assessment of children and young people
  • Monitoring
  • Recovery care
  • Complications and immediate management, including paediatric life support

Health care professionals delivering sedation should have practical experience of:

  • Effectively delivering the chosen sedation technique and managing complications
  • Observing clinical signs (for example, airway patency breathing rate and depth, pulse, pallor and cyanosis and depth of sedation)
  • Using monitoring equipment
  • All members of the sedation team should have basic life support skills and at least one member with intermediate life support when delivering minimal and moderate sedation.

Patient-centred care and consent

Children and young people undergoing sedation and their parents and carers should have the opportunity to make informed decisions about their care and treatment, in partnership with their healthcare professionals. Informed consent should be obtained for sedation as well as the procedure and documented in the patient’s notes.


Before starting sedation, confirm and record the time of last food and fluid intake in the healthcare record.

Fasting is not mandatory for:

  • Minimal sedation or
  • Moderate sedation during which the child or young person will maintain verbal contact with the healthcare professional.

Apply the 1-4-6 fasting rule for:

  • Deep sedation and moderate sedation during which the child or young person may not maintain verbal contact with the healthcare professional.

Drug Therapy

  • Choice of sedative agent depends on child factors, the experience of the clinical team and the rationale for sedation.
  • No drugs have a UK marketing authorisation specifically for sedation in all of infants, children and young people under 19 years. Refer to BNFc for up to date dosage instructions of conscious sedation for procedure.
  • As per the NICE guideline Midazolam and Chloral Hydrate will be used for the following patient group. Midazolam has a strong safety profile in inducing either minimal or moderate sedation.

Conscious sedation for Echocardiogram

For children and young people undergoing a transthoracic echocardiogram under sedation, the target level of sedation is classed as minimal to moderate: during which the child or young person will maintain verbal contact with the healthcare professional. Consider one of the following drugs EITHER:

  • Chloral Hydrate for children under 15kg :
    Oral Route : 50mg/kg (higher dose up to 100mg/kg may be used) as per BNF
  • Midazolam (oral): 0.5mg/kg as per BNFc (max dose of 20mg)

  • Ensure the patient only receives one of these drugs. They should NOT be prescribed both at the same time.

Alternatives if sedation is not successful

Trial of alternative sedation choice may be considered if safe and appropriate to do so.

Painful Procedures

For children and young people undergoing a painful procedure (for example suture laceration, chest drain removal), when the target level of sedation is minimal or moderate, consider:

  • Midazolam (oral)
  • Refer to BNFc for dosage of conscious sedation for procedure
  • Ensure adequate analgesia, monitor for combined effect of sedation and opiate analgesia (Administer analgesia at least 30 minutes prior to procedure)

Psychological Preparation

Ensure the child or young person is prepared psychologically for sedation by offering information about:

  • The procedure
  • Sensations associated with the procedure
  • Offer parent and carers to be present during sedation if appropriate
  • Obtain informed consent


For moderate sedation: continuously monitor and interpret and respond to changes in all of the following:

  • Depth of sedation
  • Respiration Rate
  • Oxygen Saturation
  • Heart rate
  • Pain and distress

The patient should have a patent airway throughout the procedure, be able to protect their airway, be haemodynamically stable and be easily aroused if they are sedated to a minimal/ moderate level. If they have any signs of the above then the person giving the sedation needs to be aware that the patient is over sedated and a senior person needs to be contacted or PICU informed perhaps.


The following age appropriate equipment should be available:

  • Suction apparatus with Yankeur sucker attached
  • Oxygen with age appropriate mask and tubing
  • Self inflating resuscitation bag
  • Audible pulse oximeter and blood pressure monitoring
  • An emergency call system to summon additional help

Facilities for observation until the child has recovered from sedation to a point where it is safe to be discharged

Post sedation

After the procedure, continue monitoring until the child or young person:

  • Has a patent airway with return of airway reflexes 
  • Has return of ventilatory function-normal Spo2 & RR for age
  • Shows protective and breathing reflexes 
  • Is haemodynamically stable
  • Is easily roused
  • Ensure vital signs have returned to normal
  • The young person is awake

Discharge Criteria

Ensure the following criteria are met before the child or young person is discharged:

  • Vital signs have returned to normal
  • The child or young person is awake and there is no risk of further reduced level of consciousness
  • Patient can be discharged from 2-4 hours post dose of sedation
  • Nausea, vomiting and pain have been adequately managed.



Ahmed, J., Patel, W., Pullattayil, A.K and Razak, A. (2022) Melatonin for non operating room sedation in paediatric population: a systematic review and meta analysis. Archives of Disease in Childhood.Vol. 107, pp. 78-85

British National Formula for children (BNFC) (2022) British Medical Journal Group. London.

Chen, Z., Lin, M., Huang, Z., et al (2019) Efficacy of chloral hydrate oral solution for sedation in paediatrics: a systematic review and meta analysis. Drug design, Development and therapy. Vol. 13.pp, 2643-2653.

Conway, A., Rolley. J and Sutherland, JR (2018) Midazolam for sedation before procedures, Cochrane Database of Systematic Reviews. Issue 12. John Wiley and Sons, Ltd.

Layangool, T., Kirawittaya, T., Attachoo, A., Et al (2008) A comparison of oral chloral hydrate and sublingual midazolam sedation for echocardiogram in children. Journal of Medical Association Thailand. Vol 91, (supplement 3) pp. S45-52.

National Institute for Health and Clinical Excellence (2018) Sedation in children and young people. Sedation for diagnostic and therapeutic procedures in children and young people. NICE Clinical Guideline 112. NICE, London.

Wheeler, D.S., Jensen, R.A., Bradley Poss, W. (2001) A Randomised, blinded comparison of chloral hydrate and midazolam sedation in children undergoing echocardiography. Clinical Pediatrics. Vol. 40, pp. 381-387.

Editorial Information

Last reviewed: 01 December 2022

Next review: 30 November 2025

Author(s): Natalie Smith and Dr Maria Ilina

Version: 4

Approved By: Cardiac Guideline Group

Reviewer Name(s): Natalie Smith

Document Id: 391