Procedural Sedation and Analgesia

General measures

Medicine treatment

• Procedural sedation and analgesia is a technique that uses medications to allow patients to tolerate unpleasant medicalinterventional or diagnostic procedures.
• It is a brief intervention, unlike sedation in intensive or palliative care. 
• It is commonly used in emergency units, dentistry and for certain endoscopic and gynaecological procedures.
• The information described does not apply to:
  - Patients receiving inhaled anaesthetics.
  - Patients receiving analgesia for pain without sedation.
  - Patients receiving sedation to manage behavioural emergencies.
  - Patients who are intubated.

GENERAL MEASURES

• Procedural sedation is a continuum: ranging from minimal sedation (anxiolysis), moderate sedation, deep sedation, to general anaesthesia. 
• Deep sedation/analgesia includes the dissociative state caused by medicines like ketamine. 
• It is often difficult to predict levels of sedation and therefore clinicians undertaking procedural sedation should be adequately trained in this technique. 
• The clinician should have a detailed understanding of the risks and benefits of the medicines used. Further, the clinician should be competent in resuscitation, airway management and assisted ventilation.
• Procedural sedation should be performed only in an area with adequate light and space, and fully functional and adequate observation and resuscitation equipment.
• Besides the clinician performing the procedure, there must be at least be one other trained health care provider present responsible for observing the patient, assisting with resuscitation if necessary and monitoring the patient. 
• The trained health care provider should observe the patient until the patient is ready for discharge.
• Patient monitoring and details of the types and amounts of all medicines used must be recorded for each procedure.
• After the procedure the patient’s fitness to leave the observation area should be formally assessed and recorded.

Sedation level:

LoE:III¹

Ketamine

• Ketamine administration leads to a dissociative state (patients may not be able to speak coherently or respond purposefully to verbal commands) and provides both sedation and analgesia. 
• Used on its own, it rarely requires airway intervention or affects breathing, but may cause hypertension and tachycardia because of sympathetic stimulation.

LoE:III²

MEDICINE TREATMENT

• Patient characteristics and required depth and duration of sedation lead to differences in dosing requirements; the doses listed serve only as a guide, and incremental further dosing may be required depending on clinical response.

Minimal sedation and anxiolysis (no analgesic effect required) 

Oral sedation may be appropriate for certain procedures.

Initial dose (further dose increments may be necessary – consult full prescribing information for each agent to determine maximum safe dosages, and reduce doses in the frail and elderly):

• Diazepam, IV, 0.1 mg/kg. (In a 60 kg patient, give boluses of 2 mg every minute; may require up to 10 mg).

LoE:II³

OR

• Midazolam, IV, 0.05 mg/kg. (In a 60 kg patient, give boluses of 1 mg every minute; may require up to 3 mg).

OR

• Nitrous oxide, inhaled 20 to 50%, in oxygen (will also provide some analgesia).

Benzodiazepines may cause respiratory depression; monitor accordingly.

Moderate sedation and analgesia

If analgesia is required, one of the above is usually combined with an opiate.  However, ketamine has analgesic activity and can be used on its own, or combined with a benzodiazepine. The opioids may cause respiratory depression; monitor accordingly.

Initial doses:

• Fentanyl, IV, 0.25 mcg/kg.
  - Titrate to effect and repeat dose every five minutes until desired level of analgesia has been achieved. 

  LoE:III⁴

OR

• Morphine, IV, 0.1 mg /kg, in increments of 2 mg every 5 minutes.

OR 

• Ketamine, IV, 0.5 mg/kg (the addition of a benzodiazepine is often recommended to reduce the incidence/severity of phenomena such as hallucinations and dreaming, but the benefit of this is unclear.)
  • Repeat doses of 0.5 mg/kg as required, every 5 to 10 minutes.

LoE:III⁵

OR

• Nitrous oxide, 20-50% inhaled, in oxygen.

LoE:III⁶

Other agents for moderate sedation

Propofol on its own provides moderate sedation for short procedures (e.g. endoscopy), but without analgesia:

• Propofol, IV, 0.5 mg/kg, repeated as 0.25 mg/kg boluses every 5 minutes as required. Specialist consultation.

LoE:III⁷

Etomidate is a short acting agent like propofol, but is more likely to cause myoclonus. It has minimal haemodynamic effects and a reliable onset of action, but no analgesic effect and is more commonly used for emergency unit procedures, rather than endoscopies.

• Etomidate, IV, 0.1 mg/kg.
  • Repeat doses of 0.05 mg/kg every 5 minutes, as required.

LoE:III⁸

Deep sedation and analgesia

• This is usually achieved with either higher doses of medications used for moderate sedation, or by combining an opiate, a benzodiazepine, and either propofol or etomidate.   
• When agents are combined, lower doses may be adequate.
• Always have another health care provider monitoring the patient and resuscitation equipment present.

Supplemental analgesia

Simple analgesics can be given before or after the procedure as appropriate:

• Paracetamol, oral, 1 g 4–6 hourly when required.
  - Maximum dose: 15 mg/kg/dose.
  - Maximum daily dose: 4 g in 24 hours.

AND/OR

• NSAID, e.g.:
  • Ibuprofen, oral, 400 mg 8 hourly with meals after the procedure.

Other routes (e.g. rectal or intramuscular) may be appropriate for certain indications and medications.

Reversal Agents must be available as medicine doses for sedation/analgesia are highly variable as are patient's age, concurrent medication and medical conditions. Supportive management is aimed at maintaining cardiorespiratory function.

For opioid toxicity:

• Naloxone, IV, 0.08 mg immediately.
  - Repeat doses as required at 2 minute intervals.
  - Maximum total dose is 10 mg. 

LoE:III⁹

Standard Treatment Guidelines and Essential Medicines List for South Africa, Hospital Level, Adults 2019 Edition