Analgesia and sedation

20.1 Analgesia and sedation



Stephen Priestley, Jason Acworth, Anthony Harrington




Essentials



1 Acute pain is one of the most common emergency department presenting problems.

2 Pain rating scales suitable to the age and development of the child are useful in establishing a child’s level of pain and assessing the adequacy of analgesia.

3 Adopt a multimodal approach to pain management (pharmacological, cognitive, behavioural and physical therapies).

4 Involve families and tailor interventions to the individual child.

5 Minimise the number of drugs used and become familiar with dose, administration and potential complications of each.

6 Combining drugs without detailed knowledge and training risks serious adverse outcomes.

7 Establish educational programs and policies for Emergency Department Procedural Sedation (EDPS).


Introduction


Acute pain in children is one of the most common reasons for presentation to the emergency department (ED).1 Pain resulting from injury, illness or necessary medical procedures is associated with increased anxiety, avoidance behaviour, systemic symptoms and parental distress. Painful experiences involve the interaction of physiological, psychological, behavioural, developmental and situational factors. Children with painful conditions can be difficult to assess and are often still underassessed and undertreated. Children often receive less analgesia than adults and the administration of analgesia varies by age, with our youngest patients at the highest risk of receiving inadequate analgesia.2,3


Children’s pain is underestimated because of a lack of adequate assessment tools and the inability to account for the wide range of children’s developmental stages. Pain is often undermedicated because of fears of oversedation, respiratory depression, addiction, and unfamiliarity with use of sedative and analgesic agents in children.3


Emergency department staff should be proficient in the assessment and safe management of pain in children. Early and appropriate analgesia may be best achieved by using a systematic approach with well-developed pain management educational programs, specific pain management policies, and benchmarked standards for time-to-analgesia within the ED.


Definitions of terms are outlined in Table 20.1.1.

























Table 20.1.1 Definitions of terms
Analgesia Relief of the perception of pain without sedation
Anxiolysis Relief of apprehension without sedation or analgesia
Sedation Lessening of awareness of the environment and or pain perception
Anaesthesia (general) Complete loss or awareness of the environment accompanied by loss of protective reflexes
Procedural sedation A technique of administering sedative or dissociation agents, with or without analgesics, to induce a state that allows the patient to tolerate unpleasant procedures while maintaining cardio-respiratory function
PSA Procedural sedation and analgesia is intended to result in a depressed level of consciousness but one that allows the patient to maintain airway control independently and continuously
EDPS Emergency Department Procedural Sedation


Assessment and measurement of pain


Pain is a subjective multifactorial experience and should be treated as such.2 Pain may be influenced by age, race, gender, culture, emotional state, cognitive ability, expectations and prior experience. Assessment of pain should be individualised, continuous, measured and documented. Over the last 20 years, pain assessment and measurement tools have been developed that are suitable for children of different ages and developmental stages. A definitive review of pain measurement in infants and children has not been published.


Accurate assessment requires a detailed pain history and consideration of the complexity of the child’s pain perception and the influence of situational, psychological and developmental factors. Because of its subjective nature, pain is best assessed using the child’s self-report, especially in older children’s pain. Observation of the child’s behaviour should be used to complement self-report tools. Four useful means of recognising pain in children are outlined in Table 20.1.2.






Table 20.1.2 Recognition of pain in children

1. The child’s self-report of pain

2. Behavioural changes, e.g. crying, guarding, facial grimacing

3. Physiological changes, e.g. pallor, tachycardia, and tachypnoea

4. Pathophysiological process, e.g. fracture or burn

Observational assessment scoring may be useful when the child is too young or self-report is not possible, e.g. children with cognitive impairment. Pain ratings provided by parents or regular carers may be used;4 however, whilst there is good correlation between the child’s and the parent’s assessment of pain intensity, parents tend to underscore more severe pain being experienced by their children.5 Physiological measures (e.g. heart rate and respiratory rate) may be useful in pain assessment in non-verbal or sedated children but may be confounded by stress reactions. For example, the infant who is hungry or frightened may give an inappropriately high score.


Specific pain assessment tools using behavioural observation have been developed for neonates and non-verbal or cognitively impaired children (e.g. FLACC and NCCPC-R tools). Common behavioural indicators of pain include: crying or vocalisation; facial expressions; body language and posture; agitation and consolability.


An understanding of the pathophysiological process can also give the clinician a surrogate indication of severity of pain.


Pain scores are typically standardised on a 0–10 scale. Pain scores are documented with other observations and vital signs. Some common pain rating scales appropriate to age are outlined in Table 20.1.3.


Table 20.1.3 Pain scoring


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Procedural sedation and analgesia: a structured approach


The goal of procedural sedation in the ED is to provide a suitable level of sedation that enables successful completion of a necessary procedure whilst minimising the risk of adverse events to the patient and enabling early safe discharge home from the department. In order to achieve this goal, consideration needs to be given to the health status of the patient, the procedure to be performed – particularly the duration and likely amount of pain – selection of an appropriate drug or combination of drugs, provision of non-pharmacological techniques, patient preparation and the informed consent and understanding of the parent(s) or carer(s).


Critical incident analysis of adverse sedation events in paediatrics has identified inadequate medical evaluation, inadequate monitoring during or after the procedure, inadequate skills in problem recognition and timely intervention and lack of experience of the practitioner with a particular age group or with an underlying medical condition as factors associated with adverse events in paediatric sedation.6


The development and implementation of procedural sedation guidelines in emergency departments, addressing quality of care for the patient, are associated with practice improvements7 and the lessening of adverse events and complications.8–16


The formulation of a sedation plan and sedation policies can be divided into:


Pre-procedure assessment.

Procedure management.

Post-procedure management.


Pre-procedure assessment and management


Health status of the patient is essential to identify elements of medical history or any current illnesses that may impact upon the safety of procedural sedation, choice of agent or consideration of alternative techniques.


Important factors to consider are listed in Table 20.1.4.






Table 20.1.4 Patient factors to consider in procedural sedation

• Current illness – URTI, active asthma, altered conscious state, haemodynamic compromise

• Age under 12 months (especially <3 months)

• Airway abnormalities – craniofacial deformities, tracheomalacia, predicted difficult airway

• Cardiac conditions – congenital heart disease, arrhythmias, cardiac failure

• Neurological conditions – seizure disorders, raised intracranial pressure

• Respiratory conditions – active asthma, upper or lower respiratory tract infections, respiratory failure

• Hepatic and renal disorders

• Prior history of failure of sedation

• Prior adverse event due to sedation, analgesia or anaesthesia

Children aged less than 1 year, and particularly the very young baby, have a higher incidence of hypoxic complications with procedural sedation and in very young infants consideration should be given to general anaesthesia with formal airway management.


While the presence of active asthma or upper respiratory tract infection is associated with a higher risk of complications, including laryngospasm, in patients undergoing general anaesthesia17 it is unclear whether this increased risk also applies to procedural sedation. Most authorities assume that it does and tailor the sedation plans accordingly.


Further history that needs to be obtained includes current medications, allergies and fasting status.


Pre-procedure fasting guidelines are a feature of most protocols developed for procedural sedation in children and aim to minimise the risk of pulmonary aspiration. Both the American Academy of Pediatrics and the American Society of Anesthesiologists (ASA) list specific fasting times for solids and liquids that vary from 2 hours to 6–8 hours, depending on the age of the child.18,19 However, these recommended times were a result of expert consensus opinion and are not specifically directed at patients in the unique ED setting. In fact, aspiration associated with paediatric procedural sedation has not been reported in the literature and there is no compelling evidence to support specific pre-procedure fasting periods for either liquids or solids.20–23


Whilst some EDs use a general fasting guideline of 2 hours for clear liquids and 4–6 hours for solids or liquids that are not clear (including milk), a number of EDs do not have strict fasting guidelines. The risk of aspiration with ED procedural sedation is likely to be significantly lower than that associated with general anaesthesia and the requirement for fasting remains a subject of debate. Fasting requirements should be adjusted for individual cases, following consideration of an individual patient’s risks of aspiration and the nature and urgency of the sedation.23


Physical examination should include patient weight, baseline vital signs including oxygen saturation, assessment of conscious state, evaluation of the airway and examination of the cardiovascular and respiratory systems.


The ASA physical status categories developed for general anaesthesia are not generally used for ED procedural sedation as it is unclear how they extrapolate to this setting.24 Following risk assessment and generation of a sedation plan, this plan should be discussed with the child’s parent or carer to obtain informed consent. A clear explanation of the sedation plan and what is to happen for the older child is often useful in an effort to allay anxiety and optimise co-operation.


The expected effects on the child, risks, benefits, alternatives and need for monitoring and observation during and after the procedure prior to safe discharge must be discussed with the parent or guardian. As the expected effects, risks and recovery times prior to discharge will vary greatly between different agents, the use of a standardised procedural sedation consent form for all sedative drugs is suboptimal. It is recommended that drug or drug combination-specific consent forms should be generated that reflect the individual features of the different agents, to clearly identify that these issues have been discussed with the child’s parent. An alternative to this involves standard documentation in the medical record that agent-specific issues were discussed with the parent(s)/carer(s).


In most EDs there is a policy that informed consent for procedural sedation is obtained in written form unless it is employed in a life- or limb-threatening situation.



Medications


A medication order containing all sedative drugs to be used should be recorded on the appropriate medication chart or sedation record, and the doses, route and time of administration should also be recorded.


Reversal drugs and life-support drugs should also be available (Table 20.1.5).












Table 20.1.5 List of drugs and equipment recommended for safe procedural sedation
Equipmenta

• Oxygen source, masks and tubing

• Suction source and suction devices

• Self-inflating bag–mask device

• Oral and nasal airways

• Endotracheal tubes and difficult airway management devices

• Laryngoscopes

• Defibrillator with paediatric paddles

• ECG monitor

• Non-invasive blood pressure measurement device
Intravenous cannulation equipment
• Oxygen saturation monitor

• Delivery system and scavenger device for continuous nitrous oxide administration

• End-tidal carbon dioxide monitor (ETCO2)
Drugsb

• Epinephrine (adrenaline)

• Atropine

• Lidocaine

• Dextrose 10%

• Reversal agents – naloxone and flumazenil

• Hydrocortisone

a All equipment must be available in varying sizes appropriate to patient population.


b Correct weight-based dose information should be readily available.



Environment


Paediatric procedural sedation must be performed in a facility that is adequate in size and has equipment available for drug administration, clinical monitoring, airway management, vascular access and cardio-respiratory resuscitation.


Sedation in environments where the area does not meet these requirements is associated with an increased level of serious adverse events.6



Equipment


Equipment must be suitable for children of all the ages and sizes being treated. The ability to recognise respiratory or circulatory compromise early with the use of monitoring equipment is essential. Devices for airway management and techniques of advanced life support are recommended, along with sedative drug-reversal agents and life-support drugs.



Intravenous access


In patients receiving intravenous (IV) sedation, the IV access should be retained until the patient’s conscious state has improved. Patients receiving sedation by a non-IV route may benefit from the safety of having an IV line placed, particularly when the level of sedation is deep or if there is a higher than usual probability of complications as a consequence of current illness or injury or comorbidities. Where an IV line is not established prior to sedation, a practitioner with skills in establishing vascular access in children must be readily available.


Recommended equipment and drugs are listed in Table 20.1.5.



Personnel


There must always be at least two clinical staff involved in procedural sedation, with at least one doctor.


One acts as the ‘sedationist’ and is responsible for giving drugs and monitoring the patient – particularly from a respiratory and circulatory perspective. The sedationist should have no other responsibilities in the procedure thus enabling that person to be able to respond as rapidly as necessary to changes in the patient’s vital signs or clinical state. If another staff member is not present, the sedationist should also be responsible for documenting observations, times and doses of drugs administered and recording specific interventions.


Staff providing and monitoring sedation must be knowledgeable about the drugs being used and be trained to identify and rapidly manage complications – particularly airway and respiratory adverse events – and be proficient in paediatric resuscitation. The role of sedationist may be filled by a nurse or doctor with appropriate knowledge and training.


The second staff member (‘the proceduralist’) is responsible for performing the procedure, e.g. fracture reduction or suturing.


When performing deep sedation (e.g.: propofol, thiopentone or other intravenous anaesthetic agents), three staff members should be present – a trained sedationist with paediatric resuscitation skills, a proceduralist and another staff member to record observations, assist the other staff as needed and liaise with the child’s parent or carer, who may often be present during the procedure.


Finally, it is recommended that there is a supervising senior doctor – generally at specialist or advanced trainee level, that has specific experience and competence in paediatric airway management and resuscitation. This person may be taking the role of sedationist but if not directly involved in the procedure it is appropriate that he or she is aware that the procedure is occurring and has guaranteed that they will be in the department and available to assist rapidly should complications arise.



Management during the procedure


A number of recommendations and statements from clinical authorities have been published detailing particular aspects of required personnel, monitoring equipment, patient preparation for procedural sedation in children both inside and outside of the operating theatre.25–27


It is essential that the team administering procedural sedation is aware that it is impossible to reliably predict in advance the level of sedation that will occur in an individual patient given a sedative drug or combination of drugs. Regardless of the intended level of sedation or route of administration, the sedation of a patient represents a continuum, and may result in the loss of the patient’s protective reflexes – a patient may move easily from a light level of sedation to deep sedation. As a consequence, it is imperative to plan for situations where the child becomes sedated to a far greater level than intended or experiences significant cardio-respiratory complications of sedation.


Accordingly, well-understood policies and procedures detailing the requirements for procedure management should be developed by EDs providing procedural sedation to children. Table 20.1.6 details the important elements of the conduct of procedural sedation management.






Table 20.1.6 Elements of safe procedural sedation management

1. Personnel

2. Environment

3. Medications

4. Risk assessment

5. Patient preparation and consent

6. Monitoring

7. Recovery

8. Documentation

9. Discharge criteria


Monitoring, observations and recording


The most important element of monitoring during sedation is close, continuous observation of the patient.


Recommended monitoring equipment includes electrocardiogram (ECG), non-invasive blood pressure measurements, oxygen saturations and end-tidal carbon dioxide monitoring (ETCO2) (Table 20.1.5).


Continuous oxygen saturation monitoring is recommended in all forms of procedural sedation as is continuous observation of colour, airway and rate and depth of ventilation.


It is recommended that intermittent heart rate and blood pressure monitoring is used when the level of sedation is deep.



Capnography


Capnography provides a more sensitive means of identifying respiratory depression or airway complications resulting from sedative agents than conventional monitoring and observation, but has been underutilised.28


With abnormalities in ventilation that are detectable by capnography and then only later evolve into the typical clinical manifestations of respiratory depression, apnoea, or airway obstruction.29–33 Oxygen desaturation is often the last sign of the complication, particularly when supplemental oxygen has been administered.29


Observation and recording of heart rate, blood pressure, respiratory rate, conscious level or sedation score, O2 saturation and ETCO2 should be recorded prior to the procedure, after sedative drug administration and at 5–10-minute intervals during the procedure, depending on the level of sedation achieved. Times of administration, drugs given, dosages and routes of administration of drugs should be clearly recorded on a time-based observation chart.


Interventions performed, such as provision of supplemental oxygen or basic airway management should also be recorded.



Supplemental oxygen


The use of supplemental oxygen is largely unstudied in children undergoing procedural sedation in the emergency department.32,34,35


The addition of supplemental oxygen has the potential to mask respiratory depression as hypoxia may not manifest even in the presence of significant hypoventilation. Use of ETCO2 monitoring is recommended when supplemental oxygen is administered as changes in ETCO2 associated with respiratory depression are detectable before the onset of hypoxia.34


Many physicians use supplemental oxygen coupled with ETCO2 monitoring with patients who are undergoing deep sedation.



Sedation scores


There is no universally validated and accepted score for recording the depth of sedation in patients undergoing procedural sedation in the emergency department.


Benefits of the use of a valid scoring method include the monitoring and recording of depth of sedation during episodes of procedural sedation along with assisting in standardisation of terminology and classification of sedation depth, particularly in clinical audit and research, looking at the effectiveness and adverse event profiles of different drugs at different doses.


These scores are observational in nature and are recorded during the episode of sedation.


A commonly used sedation score is the Children’s Hospital of Wisconsin Sedation Scale.9


The scale has seven levels of sedation ranging from 6 to 0:


6:anxious, agitated or in pain;

5:spontaneously awake without stimulus;

4:drowsy, eyes open or closed, but easily arouses to consciousness with verbal stimulus;

3:arouses to consciousness with moderate tactile or loud verbal stimulus;

2:arouses slowly to consciousness with sustained painful stimulus;

1:arouses, but not to consciousness, with painful stimulus;

0:unresponsive to painful stimulus.

Deep sedation is commonly defined as a score of 0–2 and moderate sedation as a score of 3.


The Modified Ramsay Sedation Score36 is also commonly used and ranges from a score of 1: awake and alert, through to a maximum score of 8: unresponsive to external stimuli, including pain.



Bispectral index monitoring


The advent of bispectral index (BIS) monitoring to measure the depth of anaesthesia in patients in the operating room may potentially be a useful adjunct in procedural sedation in the ED. 29,37–39


Further studies using this index will better define what role an objective measure of sedation level may play in reduced complications of oversedation along with avoidance of inadequate sedation during procedures.



Post-procedure management


It is imperative that children are closely observed and monitored in an appropriate environment following procedural sedation. Children vary greatly in their speed of recovery from sedation. This is also influenced by the drug(s) used, the route of administration and the total dosage given.


The period immediately following the completion of the procedure – with cessation of the painful or unpleasant stimulus – is a period during which cardiorespiratory depressant effects of the sedation drugs may be most apparent and it is during this time that there is an increased risk of complications.40


If the child is moved to another area following the completion of the procedure, they should continue to be closely observed and monitored by a suitably experienced nurse and resuscitation equipment should still be immediately available if needed. The frequency of vital signs observation can gradually lessen as the child awakens and the risk of cardiorespiratory complications diminishes. Generally, the frequency of vital signs observation will lessen from 5-minutely to 30-minutely as the child returns to their pre-sedation state.


Post-procedural observations should be recorded on the same time-based observation sheet as used during the procedure and evidence of improvement in conscious level and activity should also be recorded.


It is important to have standard discharge criteria, which must be met by the child prior to leaving the ED, and nursing staff caring for the child must be familiar with these. Suggested discharge criteria are listed in Table 20.1.7.






Table 20.1.7 Discharge criteria post-procedural sedation

• Normal age-specific vital signs

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Sep 7, 2016 | Posted by in EMERGENCY MEDICINE | Comments Off on Analgesia and sedation

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