Procedural sedation and analgesia levels

Procedural sedation and analgesia can be used to achieve analgesia, conscious sedation or deep sedation. While the intended outcomes of each level of sedation differ, there is overlap between the techniques used and effects achieved; see Overview of procedural sedation and analgesia levels for an overview of procedural sedation and analgesia levels. It is crucial to recognise that a patient’s level of consciousness may fluctuate during a procedure. Sedation is a continuum and it is easy to inadvertently proceed to a deeper level of sedation, especially if using potent or intravenous medication.

Note: Sedation is a continuum and it is easy to inadvertently proceed to a deeper level of sedation.

Table 1. Overview of procedural sedation and analgesia levels
Level of sedation	Desired outcomes	Drugs commonly used for procedural sedation and analgesia (combined with nonpharmacological interventions and, if appropriate for the procedures, local or regional anaesthesia) [NB1] [NB2] [NB3]
analgesia without a significantly depressed conscious state	analgesia for the duration of the procedure, then rapidly attenuated after the procedure is complete, without a significantly depressed conscious state conscious state may be altered (eg sense of euphoria) but awareness of surroundings is not depressed	nitrous oxide or methoxyflurane, and/or an opioid
conscious sedation and analgesia	analgesia and a depressed conscious state, but the patient can respond purposefully to commands	an opioid, midazolam and/or nitrous oxide used alone or in combination; methoxyflurane can also be used in children or as a single drug low-dose propofol or low-dose ketamine
deep sedation and analgesia	analgesia and deeper depression of conscious state so that the patient cannot be easily roused, but responds after repeated or painful stimulation [NB4]	ketamine or propofol plus (if required) one of an opioid (if additional analgesia is required) midazolam (if additional amnesia or anxiolysis is required) nitrous oxide (if additional analgesia or anxiolysis is required)
Note: NB1: See Choice of drug regimen for procedural sedation and analgesia for further advice. NB2: If combination therapy is used, initiate drugs sequentially so that the effect of one can be established before another is started. Adverse effects are more likely if multiple drugs are used. NB3: Adverse effects are more likely if the sedative effects of the drug used for procedural sedation and analgesia outlast the stimulating procedure. NB4: Because of the depth of sedation achieved with deep sedation, it can cause harms similar to the effects of general anaesthesia (eg impaired protective airway reflexes, respiratory depression, disturbed circulatory reflexes).

The level of sedation and analgesia required depends on:

the procedure being performed
whether the patient needs to be immobile
the anticipated severity of pain
the patient’s age and level of distress.

The level of sedation that can be safely provided depends on:

the clinical setting in which procedural sedation and analgesia will be undertaken
the available monitoring, staff, and equipment and physical facilities available
the expertise and training of the practitioner(s).

Examples of clinical scenarios in which procedural sedation and analgesia might be used gives examples of clinical scenarios in which procedural sedation and analgesia might be used, and appropriate techniques.

Figure 1. Examples of clinical scenarios in which procedural sedation and analgesia might be used

A scenario in which analgesia might be used

A basketballer has dislocated his shoulder and is in significant pain. This is the second time he has dislocated this shoulder, so it is anticipated that it will be easier to reduce.

The courtside sports physician and paramedic have the necessary training and expertise to reduce the shoulder now, and manage conscious sedation, if it were to occur. Equipment for continuous pulse oximetry and resuscitation is available.

The provision of reassurance (a nonpharmacological intervention) and inhaled methoxyflurane (a pharmacological intervention), and use of gentle technique allow the shoulder to be reduced on the court without the patient being uncomfortable.

A scenario in which conscious sedation might be used

A young adult has considerable anxiety about having a bone marrow biopsy. The procedure is scheduled to be performed in a day procedure unit.

The registrar supervising the biopsy has experience titrating intravenous sedating drugs. The nurse is credentialed to monitor patients self-administer nitrous oxide during a procedure.

Preprocedural local anaesthesia and small doses of intravenous midazolam and fentanyl, and inhaled nitrous oxide during the procedure, allow the biopsy to be performed without unnecessary distress.

A scenario in which deep sedation might be used

A 3-year-old is being treated in the emergency department of a tertiary hospital for a laceration to her forehead. The wound needs to be sutured but, despite the best efforts of her parents and the staff, the child is too distressed to allow this to be done.

In addition to the doctor repairing the laceration, an emergency physician and a nurse are available to assist. The emergency physician’s scope of practice includes administering and supervising deep sedation in young children. Monitoring and resuscitation equipment are available.

A single dose of intravenous ketamine provides 10 minutes of deep sedation, which allows the wound to be cleaned and sutured.