pain assessment in ed an evidence-based update
DESCRIPTION
This presentation delivered at the International Conference on Emergency Medicine in Dublin describes different approaches to assessing pain in emergency department patients. It summarises the evidence supporting the various approaches and makes recommendations for practice.TRANSCRIPT
PAIN ASSESSMENT IN THE EMERGENCY DEPARTMENT
AN EVIDENCE-BASED UPDATE
Anne-Maree KellyProfessor and DirectorJoseph Epstein Centre for Emergency Medicine Research @Western Health , Melbourne, Australia
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This presentation may be reproduced in part or whole for education purposes on the condition that each reproduced slide contains the following:
‘Re p ro duc e d with p e rm is s io n o f Pro fe s s o r Anne -Ma re e Ke lly , Jo s e p h Ep s te in Ce ntre fo r Em e rg e nc y Me d ic ine Re s e a rch @ We s te rn He a lth, Me lbo urne , Aus tra lia ’
@kellyam_jec
Conflicts of interest
None to declare
CAVEAT: The focus of this talk is on pain scenarios that commonly present to ED. Procedural analgesia and sedation have not been specifically addressed.
Objectives
After this presentation, participants will:
Have an understanding of the methods available to assess pain in the emergency department, including their strengths and weaknesses
Be aware of the challenges of pain assessment
The truth about pain assessment
Pain is a subjective experience….objective measurement is impossible
Pain experience is a complex phenomenon Physical and psychological dimensions In ED, usually measuring intensity/ severity Describing pain only in terms of intensity is like describing
music only in terms of loudness
Pain assessment in context
In ED there are three main variables that impact pain assessment Patient characteristics
E.g: Age, cognition, conscious state Pain characteristics
E.g: Acute vs. chronic The purpose for which we are measuring pain
E.g: pain management vs. research
`
Purpose
Pain management Indication of intensity/ severity Detection of change Identification of pain control/ need for additional pain relief
Research Precision regarding intensity/ severity and detection and
quantification of change
Methods for pain assessment
Vital signs Behavioural features Clinician assessment Patient self-report
Numerical methods Categorical methods
Desirable features of a pain scale
Valid, reliable Culturally, developmentally
appropriate Easily understood by patients
of varying education Well accepted by patients
and clinicians
Quickly and easily explained to patients
Low burden on clinician Low cost Readily available Translated/ adaptable into
various languages
Ada p te d fro m Va n Ba e y e r, 2 0 0 6
Poor performing methods
Vital sign measurements (eg pulse, blood pressure) have been shown repeatedly not to be reliable in pain assessment of individual patients.
Clinicians assessment of pain agrees very poorly with patient self report.
Both of these methods should be avoided if other methods can be used.
Easier said than done
Evidence that clinicians continue to demonstrate paternalism regarding pain assessment
Despite the evidence Despite the wide introduction of pain scoring
Measuring acute pain
Self report Preferred if possible to use
Observation scales Usually used with young children, the cognitively
impaired or those unable to communicate
Self report of pain
Verbal categorical scales Numerical rating scales Visual analogue scales Image scales e.g. FACES scales
Verbal categorical scales
Example format:
‘No ne ’‘Mild ’‘Mo de ra te ’‘Se ve re ’
Strengths: Simple Valid and reproducible
Weaknesses: Poor sensitivity to change in pain Low precision Research suggests temporal variation
in correlation with numerical scales Difficult for patients with cognitive
issues
Verbal categorical scales
Low precision and sensitivity to change in pain intensity makes these unsuitable for research use
Low sensitivity to change in pain intensity and difficulty of use by some patient groups limits utility as pain management tool
May be useful as a screening tool
Numerical rating scales
Example format: Usually 0-10 Can be administered verbally or visually Can be vertical or horizontal
Variants of NRS
Coloured scales Combine numerical with
colourimetric queues Not been shown to be
superior to NRS
Numerical rating scales
Simple, practical Valid and reliable Sensitive to short term
changes in pain Well accepted by patients Flexible administration, e.g.
by phone
Can be variation in description of the anchor numbers
? Lower precision than VAS Debate about whether truly
continuous for analysis ?Less accepted as a
research tool
Strengths Weaknesses
Visual analogue scale
Example format: Patient asked to mark the line Usually an un-hatched 100mm line Pain score is the number of mm from ‘0’ end of the line
Variants of VAS
Coloured scales Often coloured on one
side and numerical on the other
Reliable and well accepted in children and cognitively impaired
Visual analogue scales
Valid and reliable Sensitive to changes in pain Well validated as a research
tool
Reliant on vision and written response
Harder to comprehend by elderly and cognitively impaired
Patients find harder to use than NRS
Strengths Weaknesses
NRS or VAS?
Research suggests psychometric properties are very similar
NRS better accepted by patients
VAS better accepted by researchers
Recent change in opinion
Because of: Ease of use Fit with clinical pain management Patient preference Higher completion rate
NRS increasingly accepted as both clinical and research tool
Image scales
Patient presented with a set of images and asked to choose the one that best represents their pain
The image chosen corresponds with a number for analysis
Variety of similar tools
Image scales
Valid and reliable Simple to use Correlate with numerical
methods e.g. VAS Able to be used by children
and some patients with cognitive impairment
Limited experience with disease-related pain most validated on procedural
pain Questions regarding
interpretation and analysis Continuous vs. categorical
Some scales show bias at upper or lower end
Strengths Weaknesses
A bit more about analysis
Demonstrated correlation with VAS
VAS bands are not discrete
VAS bands are not the same size
Tendency to analyze as if continuous-? justified
The balance of evidence
In conscious, cognitively sound adolescents and adults: The numerical rating scale is best accepted and
validated for pain management and has growing acceptance as a research tool
VAS is best validated as a research tool but is harder to use and less accepted by patients
My opinion
Numerical rating scale is best all-round pain assessment tool
Children
Most children aged 5 or over can provide self report of pain intensity - if an age-appropriate tool is used
By 9 or 10 years, numerical rating scales or VAS are well accepted and reliable
Pain scales by age
Two major reviews Substantially in
agreement Apply to both pain
management and research
Acknowledge limited evidence for some tools
Age group Preferred scale
3-6 (Preschool)
Pieces of Hurt
4-12 Faces pain Scale-Revised
5-17 Coloured analogue scale
9+ Numerical rating scale (or VAS)
Observation scales
FLACC Faces, legs, activity,
cry, consolability Validated for post-
operative pain in children 2 months to 7 years
Alder Hay Triage Pain Score Cry/ voice, facial
expression, movement, colour, posture
Reliability and validity in early studies
Observational scales: The evidence
Solid evidence that observational pain scales under-estimate pain in children aged 3 and older
Not a surprising result
Should not be used in preference to an age-appropriate self report tool
Cognitively impaired adults
Includes patients with dementia
Self report of pain is possible by many patients in this group
Lack of evidence regarding performance of various tools for different levels of cognitive impairment
The evidence
There is some evidence that with increasing cognitive impairment, VAS and numerical rating scales are harder to use
Faces pain scale-revised Well accepted Low failure rate, even in moderate-severe impairment
Observation scales
Most not developed for use with acute pain
FLACC and PAINAD scores have been used
Limited data on validity and reliability
PAINAD score
Interesting new area of research
Pain assessment in the unconscious / intubated patient A number of tools in development Include behavioural assessments +/-
physiological parameters Varying psychometric properties Clinical utility to be established
Examples
Critical care pain observation tool (B) Behavioural pain scale (B) Non verbal adult pain assessment scale (B) Pain assessment and intervention notation
algorithm (B + P)
Some areas for further research
Reliability, validity and clinical utility of self report tools across different levels of cognitive impairment and cultural and education groups
Pain assessment in children under 6 years Pain assessment in sedated/ unconscious
patients
Take home messages
When feasible, patient self-report of pain using an appropriate tool is the most valid and reliable approach across all age and cognitive groups
Observational scales are a poor alternative
Measuring pain is not enough
All of the science of pain measurement means nothing if it does not result in action to relieve pain
Pain measurement may be the fifth ‘vital sign’ but unless a response to address it is triggered we are wasting our time
Questions?
Questions?Questions?
@kellyam_jec