Procedural sedation in Emergency Medicine 2019

Cardiac Anesthesiologist blog

Author: Gavin Lloyd

Introduction

• 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.

Indications for procedural sedation

• Have you adequately met the patients analgesic needs using titrated opioids (+/- paracetamol and ibuprofen) and/or local or regional anaesthesia? In fact, can the procedure be performed just as well using local anaesthetics +/- nitrous oxide/ oxygen mixtures?
• Have you put yourself in the patients 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 time of day, senior cover available should there be a problem, space in designated sedation areas such as the resuscitation room. Does performing procedural sedation now compromise the safety or quality of care for other patients?

Identifying at risk patients

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

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

• 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.

Pharmacological agents

• If using benzodiazepine/opioid combinations give the opioid first to allow time for it to become maximally effective before any sedative is added
• Use smaller initial doses of sedative in the elderly, debilitated and acutely ill patients

Safe practice

In this section you will cover:

• Training requirements and personnel
• Environment, equipment, monitoring and documentation
• (Patient assessment section 4)
• (Drug selection section 5)
• Consent
• Recovery and discharge
• Governance
• Pearls

Training requirements and personnel

The requirements for Emergency Department sedation are listed in table 5 and are taken from the RCoA/RCEM 2012 report².

Table 5: Requirements for ED sedation
Depth of sedation	Minimum staffing levels	Competencies of sedating practitioner	Locations and facilities	Monitoring
Minimal sedation with Entonox	One Physician or Emergency Nurse Practitioner (ENP)	Current Immediate Life Support (ILS) or Advanced Life Support (ALS) certification or equivalent agreed locally	Anywhere within the Emergency Department (ED)	Pulse oximetry
Moderate sedation/ analgesia (conscious sedation) using intravenous agents, typically benzodiazepines	One physician as sedationist and one Physician or ENP as operator and one Nurse	Current ILS or ALS certification Local sign off for Level 1 sedation training*	Resuscitation room facilities****	ECG, NIBP, pulse oximetry The use of capnography is recommended
Deep sedation/ analgesia	As above	Royal College of Anaesthetists initial assessment of competence Local sign off for Level 2 sedation training**	Resuscitation room facilities****	Standards conforming to AABGI guidelines for general anaesthesia The use of capnography is mandatory
Dissociative sedation using ketamine	As above	As above	As above	As above

Specific requirements for level 1 and 2 sedation training are illustrated in table 6.

Table 6: Training requirements for ED sedation

Level 1 sedation training (moderate sedation) ASA grading Pre-procedural assessment including prediction of difficulty in airway management Pre-procedural fasting and risk benefit assessment Consent and documentation Drug selection and preparation: benzodiazepine/opioid combinations, intervals between increments and reversal drugs Monitoring, complications (e.g. hypoxia and hypotension) and rescue strategies Governance and audit Level 2 sedation training (deep sedation/general anaesthesia) As per level 1 Drug selection with emphasis on potential alternative strategies and/or lighter sedation Safe use of propofol Safe use of ketamine

Environment, equipment, monitoring and documentation

Whilst the use of 50% nitrous oxide/oxygen mixtures +/- 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 7.

Table 7: Resuscitation room facilities (as per RCoA/RCEM joint document)

Full resuscitation equipment for the administration of basic and advanced life support. Equipment and drugs should be checked daily, and after each use. That such checks have occurred should be routinely recorded Difficult airway equipment Continuous high flow oxygen with appropriate devices for administration High pressure suction with appropriate suction catheters A trolley capable of being tipped head down Monitoring: Pulse oximeter, ECG, NIBP and continuous quantitative capnography Appropriate range of intravenous cannulae An appropriate range of intravenous fluids and infusion devices Manual handling devices

ACEP policy⁵ would suggest that your staff record the patient’s vital signs (pulse rate, blood pressure, respiratory rate and oxygen saturations) before, during and after the procedure. There is no guidance in the literature as to how often; every five minutes is probably practical. Several exemplar charts are available on the RCEM website (link), click here for an example (open a pop up with chart). Capnography monitoring and supplementary oxygen is recommended for patients in which conscious sedation or beyond is targeted. An exemplar chart is available in Appendix 1. Perform a ‘timeout’ before starting the procedure: a checklist of right patient, right side, monitoring, equipment, personnel, plan A, plan B etc. Click here for an example of this list (open a pop up with chart)

Consent

Is your department able to provide a ‘patient sedation leaflet’?

You should provide 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 8). 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 8: Levels of sedation in patient terms (adapted from the fifth National Audit Project7)
	What will this feel like?	What will I remember?	Whats 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 asleepand I may need help to breathea 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

Your patient’s vital signs should be monitored until they are no longer at risk for hypoxaemia. The largest study to date⁸ 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 9

Table 9: Guidelines for discharge

1. Vital signs should be stable and within acceptable limits. 2. Sufficient time (up to 2 hours) should have elapsed after the last administration of reversal agents (naloxone, flumazenil) to ensure that patients do not become re-sedated after reversal effects have worn off. 3. Patients should be discharged in the presence of a responsible adult who will accompany them home and be able to report any post procedural complications. 4. Patients and their escorts should be provided with written instructions regarding post procedural diet, medications, driving, other activities such as operating machinery and signing legal documents, and a phone number to be called in case of emergency. 5.

Governance

RCEM policy recommends:

• All users of sedation are adequately trained and that both knowledge and skills are maintained.
• That audit of the process and outcome of procedures performed under sedation takes place.
• A clinical governance framework exists so as to enable implementation of these recommendations.

RCEM also recommends a standardised audit tool (link)

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

Modification of your practice for children

In this final section you will revisit each of the previous sections with emphasis on the paediatric aspects. You will also examine the specific role of ketamine as per the RCEM 2016 Ketamine Sedation of Children in Emergency Departments. An additional RCEM e-learning module (Ketamine Sedation in Children) is available.

Indications for procedural sedation

You should again consider alternative strategies to sedation including the role of topical local anaesthetic agents for wound toilet^10-13, and steristrips or glue for wound closure. The role of music¹⁴, hypnosis^15,16, confusing tactile stimuli¹⁷ and blowing away pain¹⁸ are well described distraction techniques in young children. Information regarding the procedure can also be relayed to the child in the form of a story¹⁹.

The modern day all-in-one-fix-it is a tablet loaded with minions or frozen movies (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 conditions²⁰, 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 10.

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 period²¹.

Table 10: Contraindications to ketamine for procedural sedation

Age less than 12 months 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 Recent significant head injury or reduced level of consciousness Intracranial hypertension with CSF obstruction Intra-ocular pathology Previous psychotic illness Uncontrolled epilepsy Hyperthyroidism or thyroid medication Porphyria Prior adverse reaction to ketamine

Ketamine

This drug has an excellent track record in procedural sedation for children in emergency medicine from 1998²², and appears safer than benzodiazepine/opioid combinations²³.

Ketamine’s recognised side effects and their reported incidence are reported in Table 11, taken from the RCEM guideline. The emergence phenomena described with ketamine are uncommon. They are not reliably prevented with proactive benzodiazepine^24,25, but benzodiazepines are recommended in the rare event of significant recovery agitation.

Table 11: Potential complications of ketamine sedation
Airway: Noisy breathing is usually due to airway mal-position and occurs at an incidence of  < 1%. This can normally be corrected by paying careful attention to optimal airway positioning. In rare cases mild laryngospasm may occur (0.3%). The reported incidence of intubation for laryngospasm is 0.02%. A meta-analysis26 showed that low IM doses of ketamine ( < 3mg/kg) exhibited significantly less overall airway and respiratory adverse events. There were no occurrences of either laryngospasm or apnoea in the 682 children receiving lower IM doses
Vomiting: Lacrimation and salivation: Transient rash: Transient clonic movements: Significant agitation	5-10% incidence. This usually occurs during the recovery phase 10% 10% < 5 % 1.5%

Training requirements and personnel

The College guideline is clear ‘ketamine should be only used by clinicians experienced in its use and capable of managing any complications, particularly airway obstruction, apnoea and laryngospasm. The doctor managing the ketamine sedation and airway should be suitably trained and experienced in ketamine use, with a full range of advanced airway skills. Children aged between 12 and 24 months should only receive ketamine sedation from expert staff (usually a consultant)’.

Discuss with senior colleagues how you might secure competency; consider specific manikin-based workshops on laryngospasm management. An excellent discussion on the latter is available²⁷.

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 (link).

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

Key Learning Points:

• Dont 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 are confident you can ventilate the patient if necessary
• Before proceeding with sedation of an unstarved patient, a senior emergency physician with level 2 sedation training should be present.
• If using benzodiazepine/opioid combinations give the opioid first to allow time for it to become maximally effective before any sedative is added
• Use smaller initial doses of sedative in the elderly, debilitated and acutely ill patients.
• A sedationist, operator and trained nurse are required for moderate and deep sedation target levels.
• Capnography is currently recommended for both moderate and deep target sedation levels
• Monitoring for 30 minutes from the last dose of sedative agent is appropriate
• The 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

References

1. Curriculum
2. 2012 CEM report
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5. ACEP 2014 policy
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16. French GM et al. Blowing away shot pain; a technique for pain management during immunisation. Paediatrics 1994;93:384-388
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18. 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
19. Green SM, Krauss B, et al. Clinical practice guideline for emergency department ketamine dissociative sedation in children. Ann Emerg Med 2004 44:5; 460-471
20. 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
21. 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
22. 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: 7988.
23. 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: 22938
24. 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
25. Reid, C. Larygospasm after Ketamine. Resus Me. 2012
26. 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
27. Brown L, Green SM, Sherwin TS, et al. Ketamine with and without atropine; whats the risk of excessive salivation? Acad Emerg Med 2000:10:482-483