Author: Gavin Lloyd / Editors: Steve Fordham, William Gibbs / Reviewer: Mehdi Teeli / Codes: PC4, PhP1, RP1, RP7, SLO4, SLO6 / Published: 11/03/2021 / Reviewed: 13/09/2024

Sedation is a routine aspect of emergency care. The aim is clear: make the procedural experience as comfortable as possible for your patient, whilst ensuring that your practice is safe.

Sedation is a continuum which extends from a normal conscious level to being fully unresponsive. Sedation and recovery move patients along this scale, but it is difficult to accurately assess the precise degree of sedation at any one time, and even harder to maintain a patient at a pre-defined target level.

The American Society of Anesthesiologists (ASA) uses the following useful definitions for sedation1:

  • Minimal Sedation (Anxiolysis) is a drug-induced state during which patients respond normally to verbal commands. Although cognitive function and coordination may be impaired, ventilatory and cardiovascular functions are unaffected.
  • Moderate Sedation/Analgesia (‘Conscious Sedation’) is a drug-induced depression of consciousness during which patients respond purposefully to verbal commands, either alone or accompanied by light tactile stimulation. No interventions are required to maintain a patent airway, and spontaneous ventilation is adequate. Cardiovascular function is usually maintained. In the Emergency Department this is most often achieved using a combination of opioids and benzodiazepines.
  • Deep Sedation/Analgesia is a drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposefully following repeated or painful stimulation. The ability to independently maintain ventilatory function may be impaired. Patients may require assistance in maintaining a patent airway, and spontaneous ventilation may be inadequate. Cardiovascular function is usually maintained.
  • General Anaesthesia is a drug-induced loss of consciousness during which patients are not rousable, even by painful stimulation. The ability to independently maintain ventilatory function is often impaired. Patients require assistance in maintaining a patent airway, and positive pressure ventilation may be required because of depressed spontaneous ventilation or drug-induced depression of neuromuscular function. Cardiovascular function may also be impaired.

Not included in the classification is ‘dissociative sedation’, uniquely produced by ketamine it is a   trance like cataleptic state characterized by profound analgesia and amnesia, with retention of protective airway reflexes, spontaneous respirations and cardiopulmonary stability.

A core clinical learning outcome of the 2021 RCEM curriculum for CT1 and CT2 is the planning and delivery of “safe sedation using appropriate agents for ASA 1E and 2E (table 1) patients requiring procedures.2 Safe sedation of children is a key outcome for ST4 – 6 training.2

Table 1: American Society of Anesthesiologists Physical Status Classification
Class Description Examples
I Normal, healthy patient
II Mild systemic disease Asthma, controlled diabetes
III Moderate systemic disease Stable angina, diabetes with hyperglycaemia, moderate chronic obstructive pulmonary disease
IV Severe systemic disease Unstable angina, diabetic ketoacidosis
V Moribund

 

Sedation can be very useful for the successful completion of a variety of short painful procedures. However, it is worth considering:

  • Can the procedure be performed just as well using local or regional anaesthesia, Entonox or Penthrox?
  • Have you put yourself in the patient’s position and provided an empathetic approach, a clear explanation of the procedure, a distracting conversation or provided perhaps an alternative distractive medium, such as music or a tablet?
  • Is a general anaesthetic more appropriate – is the procedure more complicated than you think?
  • Does the current workload in your department allow safe procedural sedation to take place? Consider in particular the time of day, senior cover available should there be a problem, space in designated sedation areas such as the resuscitation room – will performing procedural sedation at this time compromise the safety or quality of care for other patients?

Table 2 lists some typical indications for procedural sedation and stratifies them loosely (you should take each case on its individual merits) in terms of urgency.

Table 2: Indications for procedural sedation, stratified by urgency
  • Emergent (e.g. cardioversion for life-threatening dysrhythmia, reduction of markedly angulated fracture/dislocation with soft tissue or vascular compromise, intractable pain or suffering).
  • Urgent (e.g. care of dirty wounds and lacerations, animal and human bites, fracture reduction, shoulder reduction, hip reduction, arthrocentesis, neuroimaging for trauma).
  • Semi-urgent (e.g. care of clean wounds and lacerations, foreign body removal, sexual assault examination).

Learning Bite

Don’t default to providing procedural sedation without considering alternative options or adjuncts.

In this section you will cover four questions. Which of my patients: 

  • might predictably be difficult to ventilate?
  • might predictably desaturate?
  • are more likely to regurgitate and potentially aspirate?
  • might predictably drop their blood pressure?

Pre-procedural airway evaluation is vital in order to address the first question. Table 3 lists several factors that may be associated with difficulty in airway management. A single factor in isolation may not be significant, but two or more should prompt you to reconsider your strategy.

You may find the simple pneumonic BOOTS helpful:

  • Beard
  • Obese
  • Older patient
  • Toothless
  • Snores?

Table 3: Airway assessment procedures for sedation and analgesia

History

Previous problems with anaesthesia or sedation (look in the hospital and ED records if possible)

Stridor, snoring or sleep apnoea

Advanced rheumatoid arthritis

Chromosomal abnormality (e.g. trisomy 21)

Physical Examination

Habitus

Significant obesity (especially involving the neck and facial structure)

Head and neck

Short neck, limited neck extension, decreased hyoid-mental distance (<3cm in an adult),

neck mass, cervical spine disease or trauma, tracheal deviation, dysmorphic facial features

(e.g. Pierre-Robin syndrome), excessive facial hair

Mouth

Small opening (<3cm in an adult, edentulous, protruding incisors, high arched palate, macroglossia, tonsillar hypertrophy and nonvisibule uvula)

Jaw

Micrognathia, retrognathia, trismus and significant malocclusion


Learning Bite

In your preparation for conscious sedation always ask yourself whether you are confident you can ventilate the patient using a bag and mask.

Fasting is not needed for minimal sedation, sedation with nitrous oxide/ oxygen mixtures alone, or moderate sedation where verbal contact is maintained. For procedures where deeper sedation is required, consider:

  • The urgency of the proposed procedure – In many life or limb threatening situations (e.g. cardioversion of a cardiac arrhythmia causing significant cardiovascular compromise, or an orthopaedic procedure to correct distal limb ischaemia) the patient is unable to wait and the main question becomes the choice of sedation/anaesthetic technique rather than the possibility of deferment.
  • The proposed depth and duration of sedation – Longer periods of sedation, greater sedation depth and airway interventions may stimulate airway reflexes (coughing, hiccoughs or laryngospasm) and gastro-intestinal motor responses (gagging or recurrent swallowing) leading to gastric distension, regurgitation or vomiting.
  • Patient factors – Conditions such as raised intracranial pressure, hiatus hernia and gastrointestinal obstruction are known to delay gastric emptying, and these patients may be at greater risk. Gastric emptying may also be delayed in patients who have previously undergone upper gastrointestinal surgery, in those recently injured or receiving opioids, and in pregnancy. Morbidly obese patients may be at risk, because the intra-abdominal pressure is higher and the incidence of hiatus hernia is greater than in non-obese patients. The timing of food intake in relation to the injuries also important.

For those un-starved patients needing deeper levels of sedation (for prosthetic hip relocation for example), ensure pre-oxygenation is maximised and consider employing apnoeic oxygenation so as to minimise the need for bag-valve-mask ventilation (which when delivered may insufflate the stomach and increase the likelihood of regurgitation). However, it is worth noting that pre-procedural fasting for any duration has not been demonstrated to reduce in the risk of aspiration when administering procedural sedation and analgesia, and as per RCEM guidance: “concerns about aspiration vastly exceed the actual risk.”3

Table 4 Adult: Pharmacological Agents for Procedural Sedation   

Agents for procedural sedation should be given intravenously, which gives a faster onset and allows for easier titration. The intramuscular route should be reserved for children (Section 7) and those adults with learning difficulties or acute behavioural disturbance (which lies outside of the scope of the learning session).  It is worth emphasizing the need to use smaller initial doses in the elderly and to allow the drug extra time to take effect, given the slower arm-brain circulation time in such patients. In contrast, those patients with regular alcohol consumption that comfortably exceed current recommendations may require larger sedative doses than usual to achieve the required level of sedation. Titration is not necessarily straightforward, the therapeutic window being narrow in these cases. All the drugs listed have the capacity to produce deeper levels of sedation and even anaesthesia if used in excess. Further, combinations of drugs, especially sedatives and opioids, should be employed with caution. The opioids should be given first to allow time to become maximally effective before any sedative is added. The dissociative drug ketamine offers a unique sedative state that will be considered in detail in the section on sedation for children.

You should be familiar with two reversal agents, naloxone and flumazenil. Use of reversal agents should not be considered a routine – the requirement of a reversal agent to be administered should trigger a local review of the case.3

Naloxone can be titrated 100 – 200mcg every 1 –2 minutes to reverse respiratory depression following opioid administration. Its effects may wear off before the opioid is cleared so you should consider extended patient monitoring. Naloxone may precipitate withdrawal in opioid dependent patients, and it will also antagonise any opioid analgesia.

Give flumazenil in small increments of 100 – 200mcg every minute to reverse respiratory depression following benzodiazepine use. Use it with caution in those on long term benzodiazepines, or who have consumed other drugs (prescribed or recreational) as there is the potential to precipitate seizures.

It is worth noting that reversal agents may have a shorter halflife than the drugs they are being used to reverse, so patients who require a reversal agent should be monitored for an extended period.

Staff, Equipment and Environment

Table 5 Requirements for Adult Procedural Sedation3

Whilst the use of Entonox and opioids is generally safe throughout the ED, you should ensure procedural sedation takes place in either the resuscitation room or another area with advance life support equipment. Such facilities are outlined in table 6.

Table 6: Equipment and Drugs Required for Safe Sedation3
  • Full resuscitation equipment for the administration of basic and advanced life support (including airway adjuncts, and equipment for intubation – ETT, laryngoscope, bougie etc.). Equipment should be checked daily, and after each use. Auditable record of checks should be kept.
  • Continuous high flow oxygen and appropriate devices for administration (e.g. non- rebreathe oxygen masks, bag-valve-mask)
  • High pressure suction and appropriate suction catheters
  • Trolley capable of being tipped head down
  • Monitoring: pulse oximetery, ECG, NIBP, continuous quantitative capnography
  • Appropriate range of intravenous cannulae
  • Appropriate range of intravenous fluid and infusion devices
  • Difficult airway equipment
  • Manual handling devices
  • Clock / event timer
  • Ability to summon help immediately if required
  • Adrenaline
  • Atropine
  • Dextrose 10% or 20%
  • Amiodarone
  • Naloxone
  • Flumazenil
  • Drugs for emergency intubation

The use of oxygen during procedural sedation is encouraged especially for at risk patient groups (e.g., ischaemic heart disease) and those undergoing deep sedation procedures (increased risk of short periods of apnoea).3 Monitoring during procedural sedation should include: 3 lead ECG, oxygen saturations, continuous capnography, non-invasive blood pressure3 as a standard of care. Patient vital signs should be recorded before, during and after the procedure – every five minutes is probably practical. Observations should be recorded on a chart. Perform a ‘timeout’ before starting the procedure: a checklist of right patient, right side, monitoring, equipment, personnel, plan A, plan B, etc.

Consent

All departments should have written patient information about sedation.

You should gain informed consent where appropriate, including in your discussion potential risks vs benefits, side effects and alternative options. Explaining sedation in terms they can understand is good practice (table 7). However, you will need to act in the patient’s best interest where pain and/or anxiety is excessive, or similarly where altered mental status means the patient lacks capacity. Written consent, though conventional, is not statutory and in the latter scenarios is of questionable validity. Clear documentation of the process followed in some form in the patient’s notes is essential however.

Table 7: Levels of sedation in patient terms (adapted from the fifth National Audit Project4)

  What will this feel like? What will I remember? What’s the risk related to the sedation drugs?
Not sedated; awake I am awake, possibly anxious. There may be some mild discomfort (depending on the what I am having done) Everything Nearly zero
Minimal sedation I am awake and calm. There may be some mild or brief discomfort Probably everything Very low risk
Moderate sedation I am sleepy and calm but remain in control. I may feel some mild discomfort I might remember some things Low risk
Dissociative sedation I am in a trance. I will not be in control. Any pain or sensations I feel may feel oddly remote, as if I am floating away from my body I may remember being in a trance or may recall vivid dreams I will need oxygen and special monitoring. I have a 1 in 10 chance of being sick
Deep sedation I am asleep. I will not be in control Probably very little Higher risk. My breathing may slow when I am asleep—and I may need help to breathe—a tube might be inserted into my nose,mouth or (rarely) windpipe. I will need oxygen and special monitoring
Anaesthesia I am deeply ‘asleep’ and unable to respond Very unlikely to remember anything Higher risk (but the presence of an anaesthetist increases safety). My breathing may slow or stop and my blood pressure and heart rate may fall. I will need a specialist doctor to look after my breathing and support my blood pressure and heart rate I will need oxygen and special monitoring and equipment

 

Recovery / Discharge

The patient’s vital signs should be monitored until they are no longer at risk for hypoxaemia. The largest study to date5 in which the timing of adverse outcomes can be examined included 353 children receiving ketamine and 672 receiving midazolam and fentanyl. Only 8% of the adverse events occurred after the procedure. In addition, the median time to serious adverse effects was two and a half minutes following the last intravenous medication. No primary adverse event occurred after 25 minutes from the last intravenous medication.

Guidance regarding discharge is given in Table 8.

Table 8: Guidelines for discharge3

Example of Minimum Discharge Criteria

  • Vital signs returned to baseline (no additional oxygen requirement)
  • Alert & Orientated
  • Able to tolerate oral fluids
  • Adequate analgesia
  • No / minimal nausea
  • 2 hours elapsed since use of reversal agent**
  • Appropriate care available at home

**Flumazenil, naloxone

 

Governance

RCEM guidance states that:

  • “Every ED should have a sedation lead, who should actively participate in the development and review of local Standard Operating Procedures (SOPs) for the administration of sedation. The Sedation Lead should also review adverse clinical incidents as well as having an overview of staff training and continuing professional development in sedation practice.
  • ED’s undertaking paediatric PS should have a nominated paediatric sedation lead and specific paediatric guidelines.
  • EDs should use a sedation proforma or similar to prompt safe and effective care which is auditable.
  • All EDs should routinely audit procedural sedation focusing on compliance with the use of a sedation proforma, monitoring during sedation, drugs used for sedation, use of reversal agents as well as adverse incidents. Six monthly audits involving, as a minimum, 20-30 patients depending on departmental size are recommended.
  • Sedation related adverse incidents can be defined as ‘unexpected and undesirable response(s) to medication(s) and medical intervention used to facilitate procedural sedation and analgesia that threaten or cause patient injury or discomfort.
  • The TROOPS reporting tool for adverse events should be considered as it focusses both on significant interventions (e.g., positive pressure ventilation) and outcomes (e.g., unplanned admission to hospital) without the need to define events in terms of ‘threshold’ or ‘duration’ which are often subject to clinician disagreement.
  • It should be noted that often certain interventions (e.g., airway re-positioning) are an accepted part of PS and their performance does not necessarily signify a clinical error.” However, there should be prompt analysis of any sentinel events (defined by TROOPS as “events as those which are life threatening and warrant immediate reporting and the highest level of peer scrutiny,”) such as unexpected tracheal intubation.
  • The use of an adverse reporting system whether part of a sedation proforma or separate e.g., DATIX, is recommended.”2

 

Pearls

Three clinical tips that might further enhance safety in your procedural sedation practice:

  • Use a decent size pillow pre-emptively to better achieve the “sniffing the morning air” position; your patients will consider you a saint regardless of whether it prevents airway compromise or not!
  • Tilt the head end of the trolley upright if your obese patient is hypoventilating, or if you are required to provide bag mask ventilation. Is there any reason not to have them in this position from the outset?
  • Consider a 500ml bolus of saline pre-procedure in elderly patients on hypertensive medication, with a further bolus primed in anticipation of a drop in blood pressure.

Learning Bites

  • Capnography is currently recommended for both moderate and deep target sedation levels
  • Monitoring for 30 minutes from the last dose of sedative agent is appropriate8

Indications for procedural sedation

You should again consider alternative strategies to sedation including the role of topical local anaesthetic agents for wound toilet,6-9 and steristrips or glue for wound closure. The role of music,10 hypnosis,11,12 confusing tactile stimuli13 and blowing away pain14 are well described distraction techniques in young children. Information regarding the procedure can also be relayed to the child in the form of a story.15 A game on a parent’s phone may substitute.

The modern day all-in-one-fix-it is a tablet loaded with Minions or Frozen movies (author’s personal opinion). The help of an experienced nurse and capable parent cannot be underestimated. You should consider the use of intranasal diamorphine on presentation for more painful conditions,16 as well as paracetamol and ibuprofen. You might diminish the pain on infiltration of (warmed) local anaesthetics by injecting slowly and using a fine gauge needle.

At risk children

The contraindications to ketamine sedation as listed in the RCEM guideline are illustrated below in Table 9.

With specific regard to fasting, and consistent with your approach to adults, a case-by-case risk – benefit assessment is more consistent with the current literature than setting an arbitrary fasting period.17

Table 9: Contraindications to ketamine for procedural sedation19

In addition to general contraindications:

  • Pulmonary Hypertension
  • Age less than 12 months due to an increased risk of laryngospasm and airway complications
  • A high risk of laryngospasm (active respiratory infection, active asthma)
  • Unstable or abnormal airway. Tracheal surgery or stenosis.
  • Active upper or lower respiratory tract infection
  • Proposed procedure within the mouth or pharynx
  • Patients with severe psychological problems such as cognitive or motor delay or severe behavioural problems
  • Significant cardiac disease (angina, heart failure, malignant hypertension)
  • Intracranial hypertension with CSF obstruction
  • Intra-ocular pathology (glaucoma, penetrating injury)
  • Previous psychotic illness
  • Uncontrolled epilepsy
  • Hyperthyroidism or Thyroid medication
  • Porphyria
  • Prior adverse reaction to ketamine 5 Ketamine Procedural Sedation for Children in The Emergency Department (Feb 2020)
  • Altered conscious level due to acute illness or injury
  • Drug / alcohol intoxication

 

Ketamine

Ketamine is a unique dissociative drug introduced into clinical practice in 1970. This drug has an excellent track record in procedural sedation for children in emergency medicine from 1998.18

Whilst ketamine can be given both intravenously and intramuscularly, IM injections are associated with a higher risk of vomiting and a longer recovery time. There is also a perceived safety benefit of gaining secure IV access prior to the administration of any sedative medications, lest complications occur that necessitate the administration of other drugs (such as muscle relaxant for emergency intubation). For this reason, IV ketamine is recommended over IM ketamine in most instances.

Characteristics of ketamine sedation19

  • Dissociation – trance-like state with eyes open but not responding
  • Catalepsy – normal or slightly increased muscle tone maintained
  • Analgesia – excellent analgesia is typical
  • Amnesia – usually total
  • Airway reflexes maintained
  • Cardiovascular state – blood pressure and heart rate increase slightly
  • Nystagmus is typical, usually horizontal; eyes remain open and glazed

Ketamine has a number of recognised side effects,19 including:

Mild agitation (20%). Moderate to severe agitation is less common (<2%) and may be managed with benzodiazepines. Prophylactic use of benzodiazepines is not recommended.20,21

Hypersalivation and lacrimation (<10%)22,23

Involuntary movements / ataxia (5%)

Vomiting (5-10%). Prophylactic antiemetic use may be beneficial,24 although is not recommended in RCEM guidance.

Transient rash (10%)

More significant complications of ketamine sedation are uncommon, but may include:

Noising breathing (<1%), which generally requires no action, and where action is required is often improved by airway repositioning.

Apnoea (0.3%), which generally occurs when ketamine is given rapidly, and may therefore be avoided by giving boluses over 60 seconds.

Laryngospasm (0.3%), which is more likely in children with active upper respiratory infections. It is generally transient and self-limiting. Where action is required, airway repositioning (including) Larson manoeuvre and positive airway pressure administered via a facemask are usually sufficient to “break” the spasm.25,26 Intubation (0.02%).

Training requirements and personnel

Any doctor providing sedation and airway should be suitably trained and experienced in ketamine use, with a full range of advanced airway skills. RCEM recommends that “Ketamine should only be used by clinicians with significant relevant experience in the use of ketamine when performing procedural sedation in children aged between 2-5 years.”19

Discuss with senior colleagues how you might secure competency – for example, consider specific manikin-based workshops on laryngospasm management.

At least three staff are required: a doctor to manage the sedation and airway, a clinician to perform the procedure and an experienced nurse to monitor and support the patient, family and clinical staff. Observations should be regularly taken and recorded.

Environment, Equipment, Monitoring, Documentation, Recovery and Discharge

For mixed adult and paediatric emergency departments with busy resuscitation rooms, securing a quiet child-friendly area with appropriate paediatric life support equipment may prove challenging. Likewise a quiet recovery area can be hard to come by in modern emergency medicine. The former is certainly considered essential for procedural sedation in children using either benzodiazepine/opioid combinations or ketamine; the latter may be over emphasized. Note the monitoring requirement in the College guideline – ECG, BP, respiration and pulse oximetry. Supplemental oxygen should be given and suction must be available.

Recovery should be complete between 60 and 120 minutes, depending on the dose and route used. The child can be safely discharged once they are able to ambulate and vocalise/converse at pre-sedation levels. An advice sheet should be given to the parent or guardian advising rest, quiet and supervised activity for the remainder of that day. The child should not eat or drink for two hours after discharge because of the risk of nausea and vomiting.

Downloadable appendices for information sheets of the parents and discharge advice from parents exist within the RCEM guideline.

Governance

You should subject your departmental practice to the same governance standards for paediatric procedural sedation as outlined for adults (section 6). A specific exemplar departmental guide/ monitoring chart for paediatric ketamine sedation is available on the RCEM website.

Learning Bites

  • RCEM supports the use of 1 mg/kg IV ketamine for procedural sedation in children.
  • Laryngospasm is a rare but real side effect of ketamine use, and its management should be incorporated within a regular training programme.
  • Don’t default to procedural sedation without considering alternative options or adjuncts to your strategy. The latter may enable you to use lighter levels of sedation.
  • In your preparation for procedural sedation always ask yourself whether you would be able to ventilate and oxygenate the patient if necessary.
  • The risks of aspiration, whilst small, should be considered in all patients. If a procedure is not required emergently, it may be appropriate to delay the procedure (to prolong fasting) or defer it completely in patients where aspiration risk is deemed unacceptably high.
  • Use smaller initial doses of sedative in the elderly, debilitated and acutely ill patients.
  • A minimum of three staff members is required for safe sedation. All sedation should take place in a resuscitation area, with full monitoring (ECG, SaO2, etCO2 and BP).
  • Monitoring for 30 minutes from the last dose of sedative agent is appropriate
  • IV ketamine is a safe and effective sedative agent for use in children.
  • Laryngospasm is a rare but real side effect of ketamine use, and its management should be incorporated within a regular training programme.

  1. American Society of Anesthesiologists (ASA), Statement on Continuum of Depth of Sedation: Definition of General Anesthesia and Levels of Sedation/Analgesia. Committee on Quality Management and Departmental Administration, October 2019.
  2. The Royal College of Emergency Medicine (RCEM). Curriculum 2021. 04 August 2021.
  3. The Royal College of Emergency Medicine (RCEM) Best Practice Guideline, Procedural Sedation in the Emergency Department, August 2022.
  4. Cook TM, Andrade J, Bogod DG, et al. Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland. The 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: patient experiences, human factors, sedation, consent and medicolegal issues. Anaesthesia. 2014 Oct;69(10):1102-16.
  5. Newman DH, Azer MM, Pitetti RD, Singh S. When is a patient safe for discharge after procedural sedation? The timing of adverse effect events in 1367 pediatric procedural sedations. Ann Emerg Med. 2003 Nov;42(5):627-35.
  6. Pryor GJ, Kilpatrick WR, Opp DR. Local anesthesia in minor lacerations: topical TAC vs lidocaine infiltration. Ann Emerg Med. 1980 Nov;9(11):568-71.
  7. Bonadio WA, Wagner V. Efficacy of TAC topical anesthetic for repair of pediatric lacerations. Am J Dis Child. 1988 Feb;142(2):203-5.
  8. Anderson AB, Colecchi C, Baronoski R, DeWitt TG. Local anesthesia in pediatric patients: topical TAC versus lidocaine. Ann Emerg Med. 1990 May;19(5):519-22.
  9. Hegenbarth MA, Altieri MF, et al. Comparison of topical tetracaine, adrenaline, and cocaine anesthesia with lidocaine infiltration for repair of lacerations in children. Ann Emerg Med. 1990 Jan;19(1):63-7.
  10. Menegazzi JJ, Paris PM, et al. A randomized, controlled trial of the use of music during laceration repair. Ann Emerg Med. 1991 Apr;20(4):348-50.
  11. Ewin DM. Emergency room hypnosis for the burned patient. Am J Clin Hypn. 1986 Jul;29(1):7-12.
  12. Zelter L, LeBaron S. Hypnosis and non-hypnotic techniques for reduction of pain and anxiety during painful procedures in children and adolescents with cancer. Paediatrics 1982;101:1032-1035
  13. Kuttner L. Management of young children’s acute pain an anxiety during invasive medical procedures. Paediatrician 1989;16:39-44
  14. French GM, et al. Blowing away shot pain; a technique for pain management during immunisation. Paediatrics 1994;93:384-388
  15. Harrison A. Preparing children for venous blood sampling. Pain 1991;45:299-306
  16. Kendall JM, Reeves BC, Latter VS. Multicentre randomised controlled trial of nasal diamorphine for analgesia in children and teenagers with clinical fractures. BMJ 2001; 322: 261 – 265
  17. Agrawal D, Shannon F. Manzi, Gupta R, Krauss B, et al. Preprocedural fasting state and adverse events in children undergoing procedural sedation and analgesia in a paediatric emergency department. Ann Emerg Med 2003; 42:636-646.
  18. Green SM, Rothrock S, Lynch E, et al. Intramuscular Ketamine for Pediatric Sedation in the Emergency Department: Safety Profile in 1,022 Cases. Ann Emerg Med 1998; 31:688-697
  19. The Royal College of Emergency Medicine. Ketamine Procedural Sedation for Children in the Emergency Department. Revised Feb 2020
  20. Wathen JE, Roback MG, Mackenzie T, et al. Does midazolam alter the clinical effects of intravenous ketamine sedation in children? A double-blind, randomized, controlled emergency department study. Ann Emerg Med 2000; 36: 79–88.
  21. Sherwin TS, Green SM, Khan A, et al. Does adjunctive midazolam reduce recovery agitation after ketamine sedation for pediatric procedures? A randomized, double-blind, placebo- controlled trial. Ann Emerg Med 2000; 35: 229–38
  22. Heinz P, Greelhoed GC, Wee C, et al. Is atropine needed with ketamine sedation? A prospective, randomised, double blind study. Emergency Medicine Journal 2006;23:206-209
  23. Brown L, Green SM, Sherwin TS, et al. Ketamine with and without atropine; what’s the risk of excessive salivation? Acad Emerg Med 2000:10:482-483
  24. BestBET: Ondansetron Use in Paediatric Ketamine Sedation, 6 June 2018.
  25. Green SM, Roback MG, Krauss B, et al. Predictors of Airway and Respiratory Adverse Events with Ketamine Sedation in the Emergency Department; An Individual-Patient Data Meta-analysis of 8,282 Children. Ann Emerg Med 2009;54:158-168
  26. ResusMe: Laryngospasm after Ketamine, 1June 2012.