Sedation

You should not consider sedating a patient for a procedure unless you have been trained and can deal with any emergencies that may arise, ie . If patient moves from conscious sedation to deep sedation or general anaesthesia.

Their are several levels of sedation:

1. Minimal Sedation (anxiolysis)
2. Moderate Sedation/Analgesia (“Conscious Sedation”)
3. Deep Sedation/Analgesia
4. General Anaesthesia

For most procedures in the accident and emergency department we aim for level 2 ie. conscious sedation and analgesia.

“Conscious Sedation”:  - The patient retains the ability to independently maintain an airway and respond appropriately to verbal commands, protective reflexes are normal or minimally altered.

The use of central nervous system depressants for conscious sedation, especially when used in combinations, requires careful titration and close monitoring to avoid unanticipated deep sedation or general anaesthesia.

It is important to maintain a wide margin of safety between conscious Sedation and the unconscious state of general anaesthesia where verbal communication with the patient or protective reflexes are lost.

Preparation of Patients for Conscious Sedation

Consent

Specific consent must be obtained from all patients who are to receive treatment under sedation, for the procedure and for sedation.

Escort

A responsible adult escort must accompany the patient home and assume responsibility for the patient's post-sedation care.

Medical conditions

Ensure no contra indications to sedation. See drug information below. Ensure patient has large cardio-respiratory reserve.

Monitoring:

Clinical monitoring: Colour, pulse and respiration.

Electro-mechanical: MINIMUM, Pulse oximetry and blood pressure monitoring, consider continuous ECG.

Oxygen

Place all patients about to go under sedation on Oxygen, ensure resuscitation and advanced airway support equipment available and in working order.

Fasting

Not obligatory but safer if do over sedate patient.

Reversal

Have reversal available in case patient goes from conscious sedation to deep sedation, antidote for:

Opioids (Morphine) - Naloxone

Benzodiazepines (Midazolam) - Flumazenil

Technique

At all time monitor response to medication, read BNF information on drugs used for sedation below.

In both Inhalation Sedation and intravenous conscious sedation, success is due to titrating the dose given to the patient's needs. Fixed doses or bolus techniques are unacceptable.

Inhalation sedation:

The only currently recommended technique for inhalation sedation is the use of a titrated dose of nitrous oxide with oxygen (Entonox).

Ensure patient takes slow deep breaths, takes a few minutes to take full effect.

Intravenous sedation:

During intravenous conscious sedation need to address two particular features

1. Analgesia +_ antiemetic

2. Sedation.

Suggest titrate up analgesic requirement first then add sedative, classically Morphine and Midazolam +_ Metoclopramide or Cyclizine

Analgesia - Titrated morphine to pain small 1-2 mg IVI boluses (In adults 5-15mg (Child 1-2 mg/kg)) see below for more detail

Anti emetic - Used in adults Metoclopramide 10mg IVI (beware young and elderly and extrapyramidal effects). Alternative Cyclizine 50 mg IVI see below for more detail

Sedative - Midazolam, for adults titrate 1mg boluses every few minutes (beware elderly may be very sensitive (Dose 1-10mg)) see below for more detail

Oral / Intranasal / Transmucosal Sedation:

Drugs currently used to produce these types of conscious sedation include midazolam and temazepam.

Drugs used for sedation

Information From BNF

CYCLIZINE

Indications:

Nausea, vomiting, vertigo, motion sickness, labyrinthine disorders
Contra-indications:
Sedation, cyclizine has less sedative action than the older antihistamines.

Sedating antihistamines have significant antimuscarinic activity and they should therefore be used with caution in prostatic hypertrophy, urinary retention, glaucoma and pyloroduodenal obstruction. Antihistamines should be used with caution in hepatic disease and dose reduction may be necessary in renal impairment. Caution may be required in epilepsy. Children and the elderly are more susceptible to side-effects.

Many antihistamines should be avoided in porphyria although some (e.g. chlorphenamine and cetirizine) are thought to be safe.

Side-effects:

Drowsiness is a significant side-effect with most of the older antihistamines although paradoxical stimulation may occur rarely, especially with high doses or in children and the elderly. Drowsiness may diminish after a few days of treatment and is considerably less of a problem with the newer antihistamines. Side-effects that are more common with the older antihistamines include headache, psychomotor impairment, and antimuscarinic effects such as urinary retention, dry mouth, blurred vision, and gastro-intestinal disturbances.
Other side-effects of antihistamines include palpitations and arrhythmias

Dose:

By mouth, cyclizine hydrochloride 50 mg up to 3 times daily; child 6–12 years 25 mg up to 3 times daily
By intramuscular or intravenous injection, cyclizine lactate 50 mg 3 times daily
 

FLUMAZENIL

Indications:

Reversal of sedative effects of benzodiazepines in anaesthetic, intensive care, and diagnostic procedures
Cautions:

Short-acting (repeat doses may be necessary—benzodiazepine effects may persist for at least 24 hours); benzodiazepine dependence (may precipitate withdrawal symptoms); prolonged benzodiazepine therapy for epilepsy (risk of convulsions); history of panic disorders (risk of recurrence); ensure neuromuscular blockade cleared before giving; avoid rapid injection in high-risk or anxious patients and following major surgery; hepatic impairment; head injury (rapid reversal of benzodiazepine sedation may cause convulsions); elderly, children, pregnancy, breast-feeding
Contra-indications:

Life-threatening condition (e.g. raised intracranial pressure, status epilepticus) controlled by benzodiazepines
Side-effects:

Nausea, vomiting, and flushing; if wakening too rapid, agitation, anxiety, and fear; transient increase in blood pressure and heart-rate in intensive care patients; very rarely convulsions (particularly in epileptics)
Dose:

By intravenous injection, 200 micrograms over 15 seconds, then 100 micrograms at 60-second intervals if required; usual dose range, 300–600 micrograms; max. total dose 1 mg (2 mg in intensive care); question aetiology if no response to repeated doses
By intravenous infusion, if drowsiness recurs after injection, 100–400 micrograms/hour, adjusted according to level of arousal

METOCLOPRAMIDE HYDROCHLORIDE

Indications:

Adults, nausea and vomiting, particularly in gastro-intestinal disorders and treatment with cytotoxics or radiotherapy; migraine
PATIENTS UNDER 20 YEARS. . Use restricted to severe intractable vomiting of known cause, vomiting of radiotherapy and cytotoxics, aid to gastro-intestinal intubation, pre-medication; also, dose should be determined on the basis of body-weight
Cautions:

Hepatic impairment, renal impairment; elderly, young adults, and children (measure dose accurately, preferably with a pipette); may mask underlying disorders such as cerebral irritation; epilepsy; pregnancy; porphyria

Contra-indications:

Gastro-intestinal obstruction, perforation or haemorrhage; 3–4 days after gastro-intestinal surgery; phaeochromocytoma; breast-feeding
Side-effects:

Extrapyramidal effects (especially in children and young adults), hyperprolactinaemia, occasionally tardive dyskinesia on prolonged administration; also reported, drowsiness, restlessness, diarrhoea, depression, neuroleptic malignant syndrome, rashes, pruritus, oedema; cardiac conduction abnormalities reported following intravenous administration; rarely methaemoglobinaemia (more severe in G6PD deficiency)
Dose:

By mouth, or by intramuscular injection or by intravenous injection over 1–2 minutes, 10 mg (5 mg in young adults 15–19 years under 60 kg) 3 times daily; child up to 1 year (up to 10 kg) 1 mg twice daily, 1–3 years (10–14 kg) 1 mg 2–3 times daily, 3–5 years (15–19 kg) 2 mg 2–3 times daily, 5–9 years (20–29 kg) 2 mg 3 times daily, 9–14 years (30 kg and over) 5 mg 3 times daily
Note. Daily dose of metoclopramide should not normally exceed 500 micrograms/kg, particularly for children and young adults (restricted use, see above)
For diagnostic procedures, as a single dose 5–10 minutes before examination, 10–20 mg (10 mg in young adults 15–19 years); child under 3 years 1 mg, 3–9 years 2 mg, 9–14 years 5 mg

MIDAZOLAM

Indications:

Sedation with amnesia; sedation in intensive care; premedication, induction of anaesthesia; status epilepticus [unlicensed use]
Cautions:

Hepatic impairment; renal impairment; pregnancy and breastfeeding; cardiac disease; respiratory disease; children (particularly if cardiovascular impairment); history of drug or alcohol abuse; reduce dose in elderly and debilitated; avoid prolonged use (and abrupt withdrawal thereafter); concentration of midazolam in children under 15 kg not to exceed 1 mg/mL
Contra-indications:

Myasthenia gravis; severe respiratory depression; acute pulmonary insuffuciency
Side-effects:

Gastro-intestinal disturbances, increased appetite, jaundice; hypotension, cardiac arrest, heart rate changes, anaphylaxis, thrombosis; laryngospasm, bronchospasm, respiratory depression and respiratory arrest (particularly with high doses or on rapid injection); drowsiness, confusion, ataxia, amnesia, headache, euphoria, hallucinations, fatigue, dizziness, vertigo, involuntary movements, paradoxical excitement and aggression (especially in children and elderly), dysarthria; urinary retention, incontinence, changes in libido; blood disorders; muscle weakness; visual disturbances; salivation changes; skin reactions; on intravenous injection, pain, thrombophlebitis
Dose:

Conscious sedation, by slow intravenous injection (approx. 2 mg/minute), initially 2–2.5 mg (elderly 0.5–1 mg), increased if necessary in steps of 1 mg (elderly 0.5–1 mg); usual range 3.5–7.5 mg, elderly max. 3.5 mg; child by intravenous injection over 2–3 minutes, 6 months–5 years initially 50–100 micrograms/kg, dose increased if necessary in small steps (max. total dose 6 mg), 6–12 years initially 25–50 micrograms/kg, dose increased if necessary in small steps (max. total dose 10 mg)
By intramuscular injection, child 1–15 years 50–150 micrograms/kg; max. 10 mg
By rectum (see note below), child over 6 months 300–500 micrograms/kg
Sedative in combined anaesthesia, by intravenous injection, 30–100 micrograms/kg repeated as required or by intravenous infusion, 30–100 micrograms/kg/hour (elderly lower doses needed); child not recommended
Premedication, by deep intramuscular injection, 70–100 micrograms/kg (elderly 25–50 micrograms/kg) 20–60 minutes before induction, usual dose 2–3 mg; child 1–15 years 80–200 micrograms/kg
By rectum, child over 6 months 300–500 micrograms/kg 15–30 minutes before induction
Induction, by slow intravenous injection, with premedication, 150–200 micrograms/kg (elderly 100–200 micrograms/kg); without premedication, 300–350 micrograms/kg (elderly 150–300 micrograms/kg); doses increased in steps not greater than 5 mg every 2 minutes; max. 600 micrograms/kg; child over 7 years 150 micrograms/kg
Sedation of patients receiving intensive care, by slow intravenous injection, initially 30–300 micrograms/kg given in steps of 1–2.5 mg every 2 minutes, then by slow intravenous injection or by intravenous infusion, 30–200 micrograms/kg/hour; reduce dose (or omit initial dose) in hypovolaemia, vasoconstriction, or hypothermia; lower doses may be adequate if opioid analgesic also used; neonate under 32 weeks gestational age by intravenous infusion, 30 micrograms/kg/hour, neonate over 32 weeks gestational age and child under 6 months 60 micrograms/kg/hour, over 6 months by slow intravenous injection, initially 50–200 micrograms/kg, then by intravenous infusion, 60–120 micrograms/kg/hour

NOTE. For rectal administration of the injection solution, attach a plastic applicator onto the end of a syringe; if the volume to be given rectally is too small, water for injection may be added to give a total volume of 10 mL
 

MORPHINE SALTS

Indications:

Analgesia, acute diarrhoea, cough in terminal care
Cautions:

Hypotension, hypothyroidism, asthma (avoid during attack) and decreased respiratory reserve, prostatic hypertrophy; pregnancy, breast-feeding; may precipitate coma in hepatic impairment (reduce dose or avoid but many such patients tolerate morphine well); reduce dose or avoid in renal impairment, elderly and debilitated (reduce dose); convulsive disorders, dependence (severe withdrawal symptoms if withdrawn abruptly); use of cough suppressants containing opioid analgesics not generally recommended in children and should be avoided altogether in those under at least 1 year; interactions: Appendix 1 (opioid analgesics)
PALLIATIVE CARE. In the control of pain in terminal illness these cautions should not necessarily be a deterrent to the use of opioid analgesics
Contra-indications:

Avoid in acute respiratory depression, acute alcoholism and where risk of paralytic ileus; also avoid in raised intracranial pressure or head injury (in addition to interfering with respiration, affect pupillary responses vital for neurological assessment); avoid injection in phaeochromocytoma (risk of pressor response to histamine release)
Side-effects:

Nausea and vomiting (particularly in initial stages), constipation, and drowsiness; larger doses produce respiratory depression, hypotension, and muscle rigidity; other side-effects include difficulty with micturition, ureteric or biliary spasm, dry mouth, sweating, headache, facial flushing, vertigo, bradycardia, tachycardia, palpitations, postural hypotension, hypothermia, hallucinations, dysphoria, mood changes, dependence, miosis, decreased libido or potency, rashes, urticaria and pruritus;

Overdosage:

Antidote - Naloxone
Dose:

Acute pain, by subcutaneous injection (not suitable for oedematous patients) or by intramuscular injection, 10 mg every 4 hours if necessary (15 mg for heavier well-muscled patients); neonate up to 1 month 150 micrograms/kg; infant 1–12 months 200 micrograms/kg; child 1–5 years 2.5–5 mg; child 6–12 years 5–10 mg
By slow intravenous injection, quarter to half corresponding intramuscular dose
Premedication, by subcutaneous or intramuscular injection, up to 10 mg 60–90 minutes before operation; child, by intramuscular injection, 150 micrograms/kg
Postoperative pain, by subcutaneous or intramuscular injection, 10 mg every 2–4 hours if necessary (15 mg for heavier well-muscled patients); neonate up to 1 month 150 micrograms/kg; infant 1–12 months 200 micrograms/kg; child 1–5 years 2.5–5 mg; child 6–12 years 5–10 mg
Note. In the postoperative period, the patient should be closely monitored for pain relief as well as for side-effects especially respiratory depression
Patient controlled analgesia (PCA), consult hospital protocols
Myocardial infarction, by slow intravenous injection (2 mg/minute), 10 mg followed by a further 5–10 mg if necessary; elderly or frail patients, reduce dose by half
Acute pulmonary oedema, by slow intravenous injection (2 mg/minute) 5–10 mg
Chronic pain, by mouth or by subcutaneous injection (not suitable for oedematous patients) or by intramuscular injection, 5–20 mg regularly every 4 hours; dose may be increased according to needs; oral dose should be approx. double corresponding intramuscular dose and approximately triple corresponding intramuscular diamorphine dose; by rectum, as suppositories, 15–30 mg regularly every 4 hours
Note. The doses stated above refer equally to morphine hydrochloride, sulphate, and tartrate.

NALOXONE HYDROCHLORIDE

Indications:

Reversal of opioid-induced respiratory depression; reversal of neonatal respiratory depression resulting from opioid administration to mother during labour; overdosage with opioids

Cautions:

Cardiovascular disease or those receiving cardiotoxic drugs (serious adverse cardiovascular effects reported); physical dependence on opioids (precipitates withdrawal); pain (see also under Titration of Dose, below); has short duration of action (repeated doses or infusion may be necessary to reverse effects of opioids with longer duration of action); pregnancy
TITRATION OF DOSE. In postoperative use, the dose should be titrated for each patient in order to obtain sufficient respiratory response; however, naloxone antagonises analgesia

Side-effects:

Nausea and vomiting reported; tachycardia and fibrillation also reported

Dose:

By intravenous injection, 100–200 micrograms (1.5–3 micrograms/kg); if response inadequate, increments of 100 micrograms every 2 minutes; further doses by intramuscular injection after 1–2 hours if required
child by intravenous injection, 10 micrograms/kg; subsequent dose of 100 micrograms/kg if no response; if intravenous route not possible, may be given in divided doses by intramuscular or subcutaneous injection
neonate, reversal of respiratory depression resulting from opioid administration to mother, by subcutaneous, intramuscular, or intravenous injection, 10 micrograms/kg, repeated every 2–3 minutes or by intramuscular injection, 200 micrograms (60 micrograms/kg) as a single dose at birth (onset of action slower)

NITROUS OXIDE

Nitrous oxide is used for maintenance of anaesthesia and, in sub-anaesthetic concentrations, for analgesia. For anaesthesia it is commonly used in a concentration of 50 to 70% in oxygen as part of a balanced technique in association with other inhalational or intravenous agents. Nitrous oxide is unsatisfactory as a sole anaesthetic owing to lack of potency, but is useful as part of a combination of drugs since it allows a significant reduction in dosage.

A mixture of nitrous oxide and oxygen containing 50% of each gas (Entonox®, Equanox®) is used to produce analgesia without loss of consciousness. Self-administration using a demand valve is popular in obstetric practice, for changing painful dressings, as an aid to postoperative physiotherapy, and in emergency ambulances.

Nitrous oxide may have a deleterious effect if used in patients with an air-containing closed space since nitrous oxide diffuses into such a space with a resulting increase in pressure. This effect may be dangerous in the presence of a pneumothorax which may enlarge to compromise respiration.

Special care is needed to avoid hypoxia if an anaesthetic machine is being used; machines should incorporate an anti-hypoxia device. Exposure of patients to nitrous oxide for prolonged periods, either by continuous or by intermittent administration, may result in megaloblastic anaemia owing to interference with the action of vitamin B12. For the same reason, exposure of theatre staff to nitrous oxide should be minimised. Depression of white cell formation may also occur.

PROPOFOL

Indications:

See under dose

Cautions:

There is sometimes pain on intravenous injection and significant extraneous muscle movements may occur. Convulsions, anaphylaxis, and delayed recovery from anaesthesia have occurred after propofol administration; since the onset of some convulsions can be delayed the CSM has advised special caution after day surgery. Propofol has been associated with bradycardia, occasionally profound; intravenous administration of an antimuscarinic may be necessary to prevent this.
Monitor blood-lipid concentration if risk of fat overload or if sedation longer than 3 days; pregnancy
Contra-indications:

Not to be used for sedation of ventilated children and adolescents under 17 years (risk of potentially fatal effects including metabolic acidosis, cardiac failure, rhabdomyolysis, hyperlipidaemia and hepatomegaly)
Side-effects:

Pulmonary oedema, postoperative fever reported
Dose:

1% injection
Induction of anaesthesia, by intravenous injection or infusion, 1.5–2.5 mg/kg (less in those over 55 years) at a rate of 20–40 mg every 10 seconds; child over 1 month, administer slowly until response (usual dose in child over 8 years 2.5 mg/kg, may need more in younger child e.g. 2.5–4 mg/kg)
Maintenance of anaesthesia, by intravenous injection, 25–50 mg repeated according to response or by intravenous infusion, 4–12 mg/kg/hour; child over 3 years, by intravenous infusion, 9–15 mg/kg/hour
NOTE. Propofol-Lipuro® may be used for maintenance of anaesthesia in child over 1 month, by intravenous infusion, 9–15 mg/kg/hour
Sedation in intensive care, by intravenous infusion, adult over 17 years, 0.3–4 mg/kg/hour; serious and sometimes fatal side-effects reported with prolonged infusion of doses exceeding 5 mg/kg/hour
Sedation for surgical and diagnostic procedures, initially by intravenous injection over 1–5 minutes, 0.5–1 mg/kg; maintenance, by intravenous infusion, 1.5–4.5 mg/kg/hour (additionally, if rapid increase in sedation required, by intravenous injection, 10–20 mg); those over 55 years may require lower dose; child and adolescent under 17 years not recommended

2% injection
Induction of anaesthesia, by intravenous infusion, 1.5–2.5 mg/kg (less in those over 55 years) at a rate of 20–40 mg every 10 seconds; child over 3 years, administer slowly until response (usual dose in child over 8 years 2.5 mg/kg, may need more in younger child e.g. 2.5–4 mg/kg)
Maintenance of anaesthesia, by intravenous infusion, 4–12 mg/kg/hour; child over 3 years, by intravenous infusion, 9–15 mg/kg/hour
Sedation in intensive care, by intravenous infusion, adult over 17 years, 0.3–4 mg/kg/hour

General Dental Council. Report of an expert working party of the Standing Dental Advisory Committee. General anaesthesia, sedation, and resuscitation in dentistry. (The Poswillo Report.) London: General Council, 1990.

Bell GD, McCloy RF, Charlton JE, et al. British Society of Gastroenterology: report of a working party of the Endoscopy Committee. Recommendations for standards of sedation and patient monitoring during gastrointestinal endoscopy. Gut 1991;32:823-827

Royal Colleges of Anaesthetists and Radiologists. Report of a joint working party. Sedation and anaesthesia in radiology. London: Royal Colleges of Anaesthetists and Radiologists, 1992.

Royal College of Surgeons of England. Commission on the provision of surgical services. Report of the working party on guidelines for sedation by non-anaesthetists. London: Royal College of Surgeons, 1993

Epstein, Burton S. M.D.. The American Society of Anesthesiologist's Efforts in Developing Guidelines for Sedation and Analgesia for Nonanesthesiologists: The 40th Rovenstine Lecture. Anesthesiology. 98(5):1261-1268, May 2003.

Smallman, Bettina. Pediatric sedation: can it be safely performed by non-anesthesiologists? Current Opinion in Anaesthesiology. 15(4):455-459, August 2002.

British National Formulary - accessed July 2005

Last updated 11/09/2015