Procedural Sedation

in ED

David Lamond

Procedural Sedation in the ED

Procedural sedation is an area of emergency medicine practice

that has overlap with other specialities.

Emergency physicians are specialists at providing sedation for a

wide range of age groups and procedures.

Emergency registrars should develop these skills in a safe and

supported environment which is not constrained by other

speciality practice.

The aim of this package is to provide the basic pharmacological

principles for sedation agent choice and the evidence

surrounding their current use. The specifics of monitoring and

airway techniques are not discussed in this presentation.

Procedural Sedation in ED

Outline Clinical cases

Before you start

Pharmacological agents

• Nitrous Oxide

• Fentanyl

• Midazolam

• Propofol

• Ketamine

Evidence

Clinical Vignettes

You are one of the ED registrars on shift in our busy emergency department whilst the consultant is busy in another access block meeting

The nursing team leader informs you that there are 3 patients requiring sedation and wants you to sort it out!

Patient 1

1. 7 year girl with a bead stuck in her left external auditory canal.

No medical problems, fasted for 4 hours. Very upset and

distressed.

How do you manage the sedation for this patient?

Patient 2

5 year old boy with a painful right arm after falling of the playground

at a family fast food restaurant

He has an angulated distal forearm fracture with median nerve

paraesthesia

No PMHx

He tells you that he had a hamburger and milk shake 30 minutes ago

So far he has received 60ug of intranasal fentanyl

How do you manage sedation for this boy?

What agent/s would be most appropriate?

How do you manage his fasting status?

Patient 3

3. 72 year old woman with a dislocation of her right hip

prosthesis. She is distressed and crying out with pain on any

movement

Total Hip replacement 10 yrs ago

IHD - Non STEMI 2 months ago

HT

Smoking; 40 pack/years

Asthma

Allergic to morphine – rash

How do you manage sedation for this woman?

What agent/s would be most appropriate?

Sedation agent choice?

Not a black and white answer – it depends on:

Patient age and past history

Type of procedure

Analgesic requirements

Skills of sedationist / proceduralist

Allergies

Clinically urgency

Disposition plans

Nitrous-Oxide

Pharmacodynamics: 1. Powerful analgesic

2. CVS - direct depression of myocardial contractility. Increased peripheral resistance

3. Low potency (therefore usually used in combination)

Absorption: rapid uptake (due to poor tissue solubility) low blood/gas coefficient (0.47) therefore quite insoluble in blood

Distribution: penetrates rapidly into the brain. Low solubility : rapid equilibrium with brain therefore fast induction = 1-2 minutes

Nitrous-Oxide

Metabolism: not metabolised by humans

Excretion: rapid elimination (“washout”) by lungs

Contraindications: Trapped gas e.g. pneumothorax, bowel obstruction. Head injury, difficult airway, vomiting, early pregnancy.

Toxicology: prolonged exposure to N2O causes megaloblastic anaemia (decreased methionine

synthetase activity)

Nitrous-Oxide

Special precautions: diffusion hypoxia - large

quantities diffused from blood back into alveoli at

end of sedation, therefore 100% O2 for 2 minutes at

end of procedure

Dosing: Start at 50% concentration then ↑or↓ by 10%

until sedated adequately

Issues:

• Nausea and vomiting in 15% patients

• Filters + circuit tubing changes

• Staffing

• Pregnant staff members

Fentanyl

Synthetic opioid related to phenyl piperidine.

PHARMACODYNAMICS:

Mu receptor agonist.

80% more potent than morphine with decreased respiratory depression effect.

Increased dose - muscular rigidity. (Probably via dopaminergic)

ABSORPTION: Transdermal / IM / IV

METABOLISM: Liver EXCRETION: Kidney

Fentanyl

CONTRAINDICATIONS: Children < 2 yrs

Asthma

Myaesthenia gravis

Other contraindications for narcotics

ADVERSE EFFECTS: Hypotension

respiratory depression

muscle rigidity

bradycardia

Fentanyl

DOSING:

Titration 0.25-1.0 ųg/kg depending on age,

other medications and co-morbidities

ISSUES:

Can be reversed with naloxone

Rapid action – respiratory depression most

common in first 5 mins

Rigidity only partial reversed with naloxone

Midazolam

PHARMACODYNAMICS:

Binds to gamma 2 subunit (probably benzo receptor) on GABA receptor which increases chloride channel conductance

CVS: decreases BP and increases HR in large doses.

Resp: decreases alveolar ventilation by depressing medullary centre

ABSORPTION

Well absorbed orally - H2O soluble becomes lipid soluble at physiological pH therefore crosses blood /brain barrier

DISTRIBUTION:

Distribution phase 10mins

Elimination phase 1 - 2.5 hrs

Half life = 2-4 hrs

Midazolam

METABOLISM:

Liver - rapid and complete microsomal

oxidation (phase1) to alpha-

hydroxymidazolam.

Metabolites undergo conjugation (phase 2)

EXCRETION:

Urine 50-70% as metabolite.

Midazolam

CONTRAINDICATIONS :

Pregnancy and lactation

SPECIAL PRECAUTIONS:

Severe respiratory insufficiency

Myasthenia gravis

Organic brain damage

Dependence

ADVERSE EFFECTS:

Sedative side effects which are dose dependent

Slight decrease BP and increase PR

Paradoxical reaction - agitation/excitation

Midazolam

Dosing:

Slow IV boluses 0.025-0.05 mg/kg

(reduced in Elderly)

Remember onset is 2-3mins

Issues:

Amnestic effects – discharge instructions

Cytochrome P450 3A inhibitors –

erythromycin, verapamil, diltiazem,

cimetidine

Ketamine

Ketamine is a potent sedative, amnestic, analgesic and dissociative anaesthetic agent that maintains airway reflexes and spontaneous ventilation.

Characteristics of Ketamine Dissociative State: Dissociation - the patient passes into a trance like state with

the eyes open but not responding

Catalepsy - normal or slightly increased muscle tone is maintained.

Analgesia

Amnesia is usually total

Airway reflexes are maintained.

Cardiovascular state - BP and HR tend to increase slightly

Nystagmus is typical

Ketamine

Potential Side Effects:

Unpleasant emergence phenomena - more common beyond mid adolescence.

Hypersalivation.

Transient laryngospasm

Transient apnea or respiratory depression

Emesis

Recovery agitation

Random purposeless movements, muscle twitching and rash are common

Ketamine and Laryngospasm

Incidence in general paediatric anaesthesia is 0.87%

(< 10 yrs = 1.74%)

Green et al 0.017% (n=197)

• Intubation required in two cases

• Stimulation oropharynx 9.5% - dental surgery

and tonsillectomy

Message is that incidence is rare if the oropharynx is

not stimulated! eg. Yankee sucker to back of mouth

Ketamine and Emergence Phenomena

Green et al found reported incidence between 0-10% & less common with IM

Incidence of severe emergence reactions ~ 0.1%

Less distressing for children due to their perception of reality

Two randomised controlled trials of adjunctive midazolam showed no reduction in emergence but increased incidence of desaturation

Sherwin et al Ann Emerg Med 2000;35:229-38

Wathen et al Ann Emerg Med 2000;36:579-88

Vomiting and ketamine

Green et al 8.5% incidence – no reports

of clinically significant aspiration

McGlone et al (2004) N=501 with IM

ketamine 10% incidence. No aspiration

Atropine and Ketamine

Hypersalivation occurs in 1.7%

Salivation still occurs in 12% of those

treated with atropine

IM atropine time to effect 30-120

minutes

Awaiting the randomised controlled trial

Current evidence not supportive either

way

Ketamine

DOSING:

Ketamine can be safely used without IV

access (Not according to ANZCA or

ACEM)

2-4 mg/kg IM or 0.5-1 mg/kg IV

A repeat dose of 2-4 mg/kg IM or 0.5 – 1

mg/kg IV may be given after 10 minutes if

sedation is inadequate

Ketamine

Route of

Administration

IM IV

Advantages No IV necessary Ease of repeat

dosing , slightly

faster recovery

Clinical onset 5 minutes 1 minute

Effective

sedation

15-30 minutes 10-20 minutes

Time to

discharge

(average)

100 -140 minutes 90-120 minutes

Propofol

PHARMACODYNAMICS: Mechanism of action poorly understood

ABSORPTION: IV

DISTRIBUTION: Onset of action 30 seconds

Half life 2-8 minutes

Slow redistribution from poorly perfused tissues

METABOLISM: Liver

Propofol

EXCRETION: 1 - 3 hours renally excreted < 1% unchanged

CONTRAINDICATIONS: Hypersensitivity including eggs

SPECIAL PRECAUTIONS: Convulsions with epileptics

organ failure (cardiac / hepatic / renal / resp)

Bradycardia (vagolytic)

Hypovolaemia

Pregnancy and delivery

Immediate administration as good culture medium

Propofol

ADVERSE EFFECTS: Hypotension (decreased TPR)

Transient apnoea

sexual dis-inhibition

Convulsions

DOSING: Highly variable – start at 0.5-1mg/kg with boluses

0.5 mg/kg

Elderly patient 50% of this amount

Pain on injection in 25% of patients

Consider preloading with fluids

Fasting times

Evidence summary

Prolonged pre-procedure fasting time did

not reduce the incidence of post procedure

vomiting

There was an increased incidence of

vomiting with longer fasting times (P =

0.08).

There was an increase in post procedure

vomiting with increasing age of the patients

Paediatric Propofol sedation

Lamond, D (2010) Emergency Medicine Australasia Safety profile of propofol for

paediatric procedural sedation in the Emergency Department

A systematic literature review of propofol use for

paediatric sedation outside the operating theatre

environment from 1966 to 2008

Sixty studies with a total of 17066 paediatric propofol

sedations

Paediatric Propofol sedation

Lamond, D (2010) Emergency Medicine Australasia Safety profile of propofol for

paediatric procedural sedation in the Emergency Department

Incidence of complications were;

desaturation 9.3%,

apnoea 1.9%,

assisted ventilation 1.4%,

hypotension 15.4%,

unplanned intubation 0.02%,

emesis post procedure 0.14%,

laryngospasm 0.1%

bradycardia 0.1%.

No deaths or incidences of aspiration

Paediatric Propofol sedation

Lamond, D (2010) Emergency Medicine Australasia Aug;XX(x):xxx Safety profile of

propofol for paediatric procedural sedation in the Emergency Department

Conclusions:

Propofol is associated with a low rate of minor adverse

events which are all reversible with minimal intervention

Minor adverse event rate similar rates to events experienced

with other sedation agents.

Major adverse events extremely rare

Appropriate patient and procedure selection would decrease

risks further.

Discharge Timing

CONCLUSION:

serious adverse effects rarely occur after 25 minutes from the final medication administration.

suggests that when similar medication regimens are used, discharge from the ED may be safe at approximately 30 minutes after final sedation medication administration

Sedation Planning

With experience most of the thinking about how we are going to provide

sedation for patients is done rapidly.

Having a structured process in the initial learning phases of any procedure

helps establish strong clinical reasoning as experience increases.

A suggested sedation plan is:

Risk Assessment – urgency / fasting status / benefit / alternatives

Agent/s – Nitrous / Fentanyl / Midazolam / Propofol / Ketamine

Route – Inhaled / oral / intramuscular / intravenous

Monitoring – HR / BP / ECG / SaO2 / ETCO2

Personnel – sedationist versus proceduralist

Location – appropriate resuscitation facilities

Disposition – time to discharge / supervision

Before you start

Ensure the specialist and the team leader

know you are planning a sedation

Ensure the ED sedation form is filled out

Ensure consent is obtained prior to procedure

commencement

Remember you need a designated sedation

bed with resuscitation facilities, a nurse and

sedationist and a proceduralist for all

sedations.

So what about our cases?

First step

Get them done in the right order!

Suggest:

Consider Patient 2

Consider patient 3

Consider patient 1

Patient 1

1. 7 year girl with a bead stuck in her left external auditory canal.

No medical problems, fasted for 4 hours. Very upset and

distressed.

• What are our choices in terms of agents and which ones are safer?

Hopefully now you can answer these questions and

formulate a sedation plan

Patient 1

What is the sedation plan?

Risk assessment

Agent/s

Route

Monitoring

Personnel

Location

Time to discharge

Patient 1

These are not proscriptive answers. A suggested

sedation plan would be:

Risk assessment – Well patient with no significant past

medical history who needs a semi elective sedation for a

painful procedure

Agent/s – Need to provide analgesia and sedation but

anticipate a short procedure so: fentanyl 0.5 ug/kg +

propofol using 1mg/kg initially then 0.5-1mg/kg boluses.

Alternative is ketamine 2-4mg/kg IM however will have long

sedation time and recovery time for short procedure

Route – Intravenous (allows titration but also potential for a

very short procedure)

Monitoring – BP, HR, ECG, SaO2, ETCO2

Patient 1

Sedation plan continued

Personnel – 1 nurse and 1 sedationist + 1 proceduralist

Location – fully equipped procedure room with advanced

airway and resuscitation equipment

Time to discharge – aim for discharge 30 mins after waking

up

After successfully sedating the child and

the bead being removed the team

leader reminds you that you still have 2

other sedations to do and that the

helicopter is landing with a major

trauma in 1 hours time

Patient 2

5 year old boy with a painful right arm after falling of the playground

at a family fast food restaurant

Clinically there is a n angulated distal forearm fracture with median nerve

parasthesia .No previous medical problems

He tells you that he had a hamburger and milk shake 30 minutes ago

So far he has received 60ug of intranasal fentanyl

How do you manage sedation for this boy?

What agent/s would be most appropriate?

How do you manage his fasting status?

Patient 2

Sedation Plan:

Risk Assessment:

• procedure is clinically urgent given that there is neurological

compromise

• Patient is still probably going to need a definitive closed

reduction under fluroscopic guidance

• How long until he can go to the operating theatre? Probably

hours given the trauma soon to arrive

• Very little evidence to suggest that fasting status has a

relationship with aspiration related complications in sedation

• Patient is well with no other injuries or significant past medical

history

Patient 2

Sedation plan continued…….

Agent/s – propofol titrated in 0.5-1mg/kg boluses OR

ketamine titrated IV at 0.5mg/kg. Nitrous not considered

due to high emesis rate and limited depth of sedation.

Midazolam also difficult to titrate to appropriate sedation

depth. May need some pre sedation analgesia with IN

fentanyl or IV Morphine. Ensure you adjust your sedation

accordingly

Route - intravenous

Monitoring - BP, HR, ECG, SaO2, ETCO2

Personnel - 1 nurse and 1 sedationist + 2 proceduralists

Location - fully equipped procedure room with advanced

airway and resuscitation equipment

Time to discharge – likely admission

The boys arm is successfully reduced and

he is waiting for repeat xray

The Orthopaedic registrar keeps asking

when can we reduce patient 3’s hip

Patient 3

3. 72 year old woman with a dislocation of her right hip

prosthesis. She is distressed and crying out with pain on any

movement

Total Hip replacement 10 yrs ago

IHD - Non STEMI 2 months ago

HT

Smoking; 40 pack/years

Asthma

Allergic to morphine – rash

How do you manage sedation for this woman?

What agent/s would be most appropriate?

How do you manage his fasting status?

Patient 3

This represents a challenging problem especially when

you are standing in front of a patient who is

distressed:

Risk Assessment:

• Significant co morbidities

– Smoker

– Lung disease

– IHD with very recent myocardial infarction

– HT – presumption is that maybe taking ACE

inhibitors + beta blockers which added to potential

interactions with sedation agents

Patient 3

Risk assessment continued... • Any degree of hypoxia or hypotension likely to precipitate

myocardial ischaemia / infarction

• Procedure is semi urgent but given prosthetic hip and

limb not threatened can be safely delayed

• Major trauma about to arrive and this patient will require

significant senior resources for sedation

Overall assessment is:

• this is not a patient that should receive procedural

sedation in the ED and it should be performed in OT

under anaesthetic supervision

• Immediate goal should be good analgesia and facilitating

transfer to OT

references

Sherwin et al Ann Emerg Med 2000;35:229-38

Wathen et al Ann Emerg Med 2000;36:579-88

Preprocedural fasting state and adverse events in children undergoing procedural sedation and analgesia in

a pediatric emergency department Ann Emerg Med. 2003 Nov;42(5):636-46

Treston G Emerg Med Australas. 2004 Apr;16(2):145-50. Prolonged pre-procedure fasting time is

unnecessary when using titrated intravenous ketamine for paediatric procedural sedation

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

Lamond, D (2010) Emergency Medicine Australasia Safety profile of propofol for paediatric procedural

sedation in the Emergency Department. Emerg Med Australas

Summary

Agent choice and dose are decisions

which vary with the patient, the

procedure and the ED as a whole.

Nuances of procedural sedation are

best learnt at the bedside with an

experienced mentor

ED procedural sedation is extremely

safe when performed under correct

conditions

MCQs

What is the IMI dose of Ketamine to

suture a facial wound in a 25kg 7 year

old.

A. 50-100mg

B. 25-50mg

C. 100-150mg

D. 125-175mg

What would be the most appropriate

sedation plan for a 90kg footballer with

a dislocated shoulder

A. Ketamine IV 40mg with fentanyl 25mcg

B. Propofol IV 60mg with subsequent

titrated boluses

C. Propofol IV 180mg bolus

D. Nitrous Oxide 30%

What is the most appropriate sedation

plan for a 85 yr old lady with home O2

for COPD and a offended distal radius

fracture.

A. Propofol 60mg

B. Ketamine 90mg

C. Fentanyl 50mcg

D. Not for ED sedation

What monitoring is required for a

propofol sedation?

A. Cardiac, Sats

B. Cardiac, ET CO2

C. Cardiac, Sats, ETCO2

D. Sats only

IV access is required for all ketamine

sedations

True

False

What would be the most appropriate

sedation for a reduction of a fracture

dislocation ankle in a 35 yr old healthy

female

A. Ketamine 200mg IM

B. Midazolam 3mg IV

C. Fentanyl 100mcg IV

D. Fentanyl 100mcg and Propofol 30mg IV

What are the minimum requirements prior to commencing a sedation

A. Consent and an assistant

B. Consent, a sedation form and an assistant

C. Consent, a sedation form, an assistant and a ETT loaded on a bougie

D. Consent, a sedation form, an assistant, an ETT and metaraminol drawn up.