Ketamine sedation in Starship Children's Emergency Department

Important points

• This guideline is for the use of ketamine sedation in Starship Hospital Children’s Emergency Department (CED).

• Ketamine use in rapid sequence induction (RSI) is not covered in this guideline.

• Remember that no sets of guidelines can give the correct course of action for every clinical circumstance and senior medical staff, especially CED senior medical officers, are available to assist with clinical decision making.

Introduction

• Ketamine is a synthetic phencyclidine derivative that causes a dissociative sedative state through binding with the NMDA (N-methyl-D-aspartate) receptor.

• Characteristics of ketamine “dissociative state”:

  • Dissociation: trance-like state – eyes remain open, but patient does not respond

  • Catalepsy: normal or slightly increased muscle tone; occasional muscular clonus may occur

  • Anxiolysis

  • Analgesia (substantial or complete)

  • Amnesia (total)

  • Maintenance of protective airway reflexes

  • Cardiovascular stability: heart rate and blood pressure typically increase

  • Nystagmus

• Dissociation from ketamine is either present or absent, with a narrow transition zone, and has no observable progression or depth, therefore further dosing does not cause deeper sedation.

• Ketamine has a wide margin of safety.

• In paediatric procedural sedation, ketamine alone has been shown to be safer than ketamine in conjunction with fentanyl, ketamine in conjunction with midazolam, and ketamine in conjunction with propofol. Ketamine alone is also safer than propofol alone, and propofol in conjunction with fentanyl.

• Ketamine onset:

  • Clinical onset (approximately) 1 minute

  • Effective sedation 10 – 20 minutes

  • Time to discharge 90 minutes

Possible side effects

Side effects of ketamine:

• Agitation (20%)

• Hypersalivation and lacrimation (<10%). Co-administration of atropine is not required.

• Vomiting (5-10%)

• Transient rash (10%)

• Involuntary movements/ataxia (5%)

Serious adverse events of ketamine:

• Apnoea (0.3%). Usually due to rapid bolusing of ketamine. Slower IV administration over 60 seconds reduces the risk. May require airway repositioning or BVM ventilation.

• Airway misalignment/noisy breathing (1%). Basic airway repositioning usually sufficient to resolve this.

• Laryngospasm (0.3%). Risk is higher in children who undergo stimulation of posterior pharynx (e.g. deep oral cavity suturing) and children with URTI. Airway repositioning and BVM ventilation usually suffice in most cases. Reported incidence of intubation with laryngospasm is 0.02% (1 in 5000). See section on management of laryngospasm.

• Emergence phenomenon. Ketamine can induce agitation and hallucinations as dissociative effects wear off. Uncommon in children under 10 years old (1.6%), but more common beyond mid-adolescence (1 in 3 in adults). Can be managed with benzodiazepines on occurrence, but prophylactic benzodiazepines are not required.

Patient selection

• Ketamine should be used to facilitate short painful procedures, e.g.:

  • Fracture reduction/manipulation

  • Joint dislocation

  • Suturing of small lacerations

  • Incision and drainage of abscess

  • Facilitation of femoral/fascia iliaca block for femoral fracture. In this setting ketamine may even be used to facilitate patient transfer into traction

  • Insertion of tube thoracostomy

  • Foreign body removal

• The ketamine doses advised for procedural sedation are designed to leave the patient capable of maintaining their airway. There is a significant risk of failure of sedation if the procedure is prolonged. If a procedure is likely to be longer than 20 minutes, a general anaesthesia should be considered as an alternative. Examples of procedures that fall into this group are:

  • Repair of large lacerations requiring increased number of sutures

  • Open fractures

  • Limb/digital amputations

• Patients with ASA status I and II are appropriate candidates for procedural sedation in ED.

• Patients with an upper respiratory tract infection who are otherwise well can receive procedural sedation with ketamine in CED. However, patients with a lower respiratory tract infection or an acute asthma attack should not receive procedural sedation with ketamine in CED.

Contraindications

Absolute contraindications

1. ASA class III or above

2. Current lower respiratory tract illness, e.g., pneumonia, asthma, viral wheeze

3. Current croup

4. Underlying airway disease, e.g., tracheal stenosis, laryngomalacia, history of previous airway surgery

5. Known difficult airway

6. Underlying cardiac disease where increased heart rate and workload are contraindicated, e.g., ischaemic heart disease, hypertension, cardiac failure, Wolff-Parkinson-White

7. Hyperthyroidism or thyroxine replacement

8. Porphyria

9. Uncontrolled epilepsy

10. Bowel obstruction

11. Glaucoma or acute globe injury

12. Previous psychotic illness

13. Previous/known reaction to ketamine

Relative contraindications

1. Children with severe autism

2. Children under the age of 1

Others

1. Clinician's discretion

Pre-sedation assessment

1. Age and weight

2. Fasting status

   • It is important to note the fasting status of the patient (in case patient requires advanced airway management from airway complications of ketamine).

   • However, a non-fasted status is NOT a contraindication to ketamine sedation.

3. ASA status

4. Pre-sedation level of consciousness

5. Medical History:

   • Airway: e.g., Obstructive sleep apnoea, large tonsils, airway malacia, current croup

   • Respiratory: e.g., Asthma, bronchiectasis, cystic fibrosis

   • Cardiac: e.g., Congenital heart disease (pre or post repair), congestive heart failure, arrhythmia

   • Neurology: e.g., Seizure disorder, VP shunts, neuromuscular disease, cerebral palsy

   • Psychiatric/developmental/behavioural: e.g., Autism spectrum disorder

   • Others

6. Current medications and allergies

7. Previous anaesthetic and sedation history

8. Physical examination

   • Standard physical exam including cardiorespiratory, airway, level of consciousness

   • LEMON is important. Please complete ALL component in LEMON in your pre-sedation assessment:

Image shared from the iEM website ( https://iem-student.org/2018/08/01/assessing-airway-difficulty-lemon/), under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License (https://creativecommons.org/licenses/by-nc-sa/4.0/). No changes were made to the original image

Informed consent

• Informed verbal consent is required for ketamine. Please also provide ketamine advice sheet.

• Drug to be used (ketamine) and method of administration (IV).

• Desired behaviour or expected response to sedation.

• Expected duration and recovery period.

• Possible adverse effects.

• Alternatives to sedation (this is usually a formal general anaesthesia in the operating theatre, for which the child will definitely require advanced airway managements)

Fasting status

• Children undertaking procedural sedation with ketamine do not need to be fasted.

• Research has shown neither statistically significant nor clinically significant increase in adverse events in the unfasted patients.

• Cravero et al (2006) – in a series of over 30,000 children undergoing procedural sedation, only one episode of aspiration was reported (and this was in a fasted patient).

Personnel

At least 3 staff members are required for procedural sedation with ketamine in CED:

1. CED SMO/Registrar/NP performs ketamine and provides monitoring of patient

2. CED nurse assists in patient monitoring and procedure

3. Clinician performing procedure

End tidal CO₂ monitoring and capnography in ketamine sedation

• Capnography is the earliest indicator of airway or respiratory compromise and can rapidly identity the common adverse events associated with procedural sedation including apnoea, hypoventilation, upper airway obstruction.

• Criteria for end tidal CO2 monitoring and capnography in ketamine sedation in CED:

  • Age under 2 years or

  • Concurrent upper respiratory tract infection or

  • Patient has received single opioid dose in the past 2 hours or

  • Patient has received more than one opioid dose or

  • Ketamine use in radiology department to facilitate imaging or

  • At clinician’s discretion

• The capnogram, corresponding to a single tidal breath, is described as having four phases:

  • Phase I: Dead space ventilation (Concentration of CO2 is zero as airway dead space is exhaled)

  • Phase II: Ascending phase (Concentration of CO2 increases rapidly as alveolar gas exits the airway)

  • Phase III: Alveolar plateau (Concentration of CO2 is relatively constant and reflects the concentration of CO2 in the alveolar gas)

  • Phase IV: Inspiratory limb (Concentration of CO2 decreases to zero as atmospheric air enters the airway)

This image was reproduced from Krauss B, Hess DR. Capnography for procedural sedation and analgesia in the emergency department. Ann Emerg Med. 2007 Aug;50(2):172-81. doi: 10.1016/j.annemergmed.2006.10.016. Epub 2007 Jan 12. PMID: 17222941 with the consent of the corresponding author

• Examples of abnormal capnograms:

These tables were reproduced from Krauss B, Hess DR. Capnography for procedural sedation and analgesia in the emergency department. Ann Emerg Med. 2007 Aug;50(2):172-81. doi: 10.1016/j.annemergmed.2006.10.016. Epub 2007 Jan 12. PMID: 17222941 with the consent of the corresponding author

Checklist prior to starting ketamine procedural sedation in CED

1. Pre-sedation assessment done and documented (in CED IV sedation sheet)

2. CED SMO and nurse coordinator informed about sedation

3. Informed verbal consent

4. Required personnel all present

5. Confirm correct patient by checking patient bracelet/with patient/with parent(s)

6. Emergency resuscitation sheet by weight present (pre-printed ones are present in Procedure room 2, but please remember that endotracheal tube sizes should be AGE based, rather than weight based)

7. Prefilled ketamine syringe (100mg/10mL)

8. Emergency drugs present (in the “lunch box”)

9. Confirm dose of paralytic drug (suxamethonium or rocuronium) by weight

10. Check suction working

11. Check oxygen supply working and confirm appropriately sized oxygen mask

12. Prepare appropriately sized laryngoscope, endotracheal tube, laryngeal mask airway, oropharyngeal airway, bag valve mask ventilation device

13. Ensure patient has appropriate monitoring present (3-lead cardiac monitoring, oxygen saturation monitoring, and if indicated, end tidal CO2 and capnography monitoring)

Ketamine dosing

Management of complications

These are rare.

1. Severe emergence phenomenon – If the patient is severely distressed, IV midazolam can be given in small incremental doses of 0.05mg/kg – 0.1mg/kg

2. Intractable vomiting post procedure – consider use of IV ondansetron at a dose of 0.1mg/kg (up to 4mg) via slow IV push

3. Airway Complications

   • Push emergency bell ASAP to get help

   • Apnoea/airway obstruction: Airway manoeuvre + bag valve mask ventilation. Consider two-person ventilation or laryngeal mask airway if difficult to ventilate. Intubation is rarely required.

   • Laryngospasm:

This image was reproduced from Hampson-Evans D, Morgan P, Farrar M. Pediatric laryngospasm. Paediatr Anaesth. Apr 2008;18(4):303-7. Doi:10.1111/j.1460-9592.2008.02446.x with the consent of the corresponding author.

Image shared from the Life in the Fast Lane website ( https://litfl.com/laryngospasm/), under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License (https://creativecommons.org/licenses/by-nc-sa/4.0/). No changes were made to the original image

This image was reproduced from Egbuta C, Evans F. Extubation of children in the operating theatre. BJA Educ. 2022 Feb;22(2):75-81. doi: 10.1016/j.bjae.2021.10.003. Epub 2021 Dec 22. PMID: 35035996; PMCID:PMC8749383 with the consent of the corresponding author.

Larson’s manoeuvre: apply firm pressure on Larson’s point and simultaneously push forward similar to a jaw thrust manoeuvre. This causes pain over the styloid process and relaxes the cord.

Larson’s point is located behind the lobule of the pinna (of the ear), bounded anteriorly by the ascending ramus of the mandible adjacent to the condyle, posteriorly by the mastoid process of the temporal bone, and cephalad by the base of the skull.

Discharge criteria

• Clearly defined discharge criteria can reduce time spent in recovery without compromising patient safety.

• Post sedation and during the recovery phase, the patient will be monitored by the nursing team based on current nursing monitoring guidelines in the CED.

• Patient can be discharged home when vital signs have returned to normal, and he/she is awake with good control of protective reflexes.
  

Ketamine accreditation in Starship Children's Emergency Department (CED)

To achieve ketamine accreditation in CED, you will be required to complete these 2 components:

1. Complete the Ketamine Module at www.Starshippem.com : Please read the online module and complete the MCQ (link present at the end of the notes). You will need to achieve 8 or more correct answers (out of 10 questions) to pass this component. You can re-sit this MCQ as many times as you want – just remember to enter your email address and name prior to starting the MCQ.

2. Complete the Ketamine Sign-Off:

   1. If you have previously achieved ketamine accreditation for procedural sedation in children (either in CED or in another emergency department), you are required to successfully pass these requirements:

      1. RACP trainees: Observe one ketamine sedation, then do one directly supervised ketamine sedation (supervised by SMO)

      2. ACEM trainees: one directly supervised ketamine sedation (supervised by SMO) done as a formal DOPS (direct observation of procedural skills)

   2. If you have not previously achieved ketamine accreditation for procedural sedation in children, you are required to:

      1. Observe one ketamine sedation

      2. Do two directly supervised ketamine sedation (supervised by SMO)

      3. Do three indirectly supervised ketamine sedation (supervised by SMO)

      4. Do one final directly supervised ketamine sedation (supervised by SMO) for “sign-off”

The ketamine sign-off sheet is located in Procedure room 2 in CED.