Lecture 4 Flashcards
Pain Measurement in Humans and Animals
What is a thermode?
A device that you place on the skin that can be heated up.
What is the cold presser test?
Someone places their hand or arm in cold water.
What is a pressure algometer?
You put it on a particular body part and press down harder and harder until the patient says they feel pain.
What is a pain threshold and what is the problem with measuring it?
Pain threshold is how much of a specific stimulus (heat, cold, pressure) someone can take until it becomes pain. The problem with pain threshold is that it’s hard to figure out the exact second that something goes from not being painful to being painful.
What is pain tolerance and what is the problem with measuring it?
Pain tolerance is how much pain stimulus you can take until it becomes too much. The problem with pain tolerance as a measure is that it can be affected by all sorts of things (someone forcing themselves to hold on for longer than they normally would because of the fact that it’s a study, etc.).
What was the first pain rating scale that was developed?
The Verbal Pain Intensity Scale (VRS).
What is the VRS?
For this scale, you simply pick the adjective you think most closely defines your pain. The problem with transferring this verbal scale to one with numbers is that most numerical scales have 11 points, whereas this one has 6. The other issue is that you would have to accept the fact that the difference between ‘mild’ and ‘moderate’ is the same as the difference between ‘moderate’ and ‘severe’.
What is NRS?
A numeric rating scale in which there are 11 points from 0-10. The difficulty with this scale is that one person’s 4 can be another person’s 7, and people tend to overexaggerate their pain level or simply do not understand the task they’ve been given. It’s also difficult for a patient to give an average of their pain, especially if they’re suffering from chronic pain.
What is VAS?
The visual analogue scale is when you give someone a blank line with ‘no pain’ at one end and ‘worst pain imaginable’ on the other and ask them to draw a notch anywhere on the line. There are no numbers on the line, but it can be converted into a numerical rating by measuring the notch distance along the 10cm line. This is better than NRS, as it’s more difficult to falsify your rating to appease your doctor or get them to give you a different perscription.
What is the FACES scale?
It is mostly used with young children. The issue with this scale was that it originally depicted no pain as happiness rather than neutrality.
Do men or women have bigger pain scales?
Women tend to have bigger pain scales than men, as they experience pain more commonly in their lifetime than men do.
What is the FLACC scale?
It is a pain scale used for babies. It stands for ‘Face, Legs, Activity, Cry, and Consolability.’ Each of those 5 things are measured from 0-2.
Who created the Facial Action Coding System?
Paul Ekman. He was the first to understand that emotional expressions are constant from person to person, from culture to culture, and across age and species.
Who is Ron Melzack and what did he do?
He collected many words that have been used to describe pain and then divided them into categories. The categories were divided into Sensory (temporal, spatial, punctate pressure, incisive pressure, constrictive pressure, traction pressure, thermal, brightness, dullness, and miscellaneous), Affective (tension, autonomic, fear, punishment, and miscellaneous), and Emotional (anchor words). He then turned these descriptive words into the McGill pain questionnaire.
What is the McGill Pain Questionnaire?
It was created by Ron Melzack. You would pick one word from each of the 20 categories that most represented your pain. You could also draw on a body map where your pain was occurring and fill out a PPI (present pain index, which is 6-point VRS). Unfortunately, it didn’t help doctors very much with diagnosing pain problems. It was, however, good at helping doctors find neuropathic pain, as it has a lot of heat and electrical components.
What is the DN4 neuropathic pain questionnaire used for?
It’s an easy way to distinguish between neuropathic and non-neuropathic pain. The higher you score out of 10, the more likely it is that you have neuropathic pain.
What is QST, and what are the two ways of doing it?
Quantitive sensory testing is systematically measuring thresholds and tolerances. You can either do QST by bedside examination or by doing true QST. QST measures the thresholds and tolerances of both mechanical and thermal stimuli.
What are the three ways of testing pain directly in the muscle?
You can electrically stimulate the muscle, you can apply deep mechanical pressure, or you can inject chemicals into the muscles.
What is the most popular biomarker for pain?
Imaging.
Can fMRI be used as a biomarker for pain?
Kind of. Cortical activating during the fMRI agreed with the self-rating scores people gave, but the same would happen if people were hypnotized into feeling a higher pain level, so cortical levels can be fooled into recognizing something as pain even with no noxious stimulus.
What are the challenges of using animals in pain research?
- they are the wrong species
- they don’t talk
- rats and mice are prey species, and might hide their pain as a survival response
- animals are much tougher than humans
- there are lots of ethical issues surrounding animal experimentation
What do consequentialist ethics say about animal experimentation?
Consequentialist ethics say that whether or not you should do something depends on the potential consequences of the action. So if experimenting on an animal has a positive consequence for society, do it.
What do deontologist ethics say about animal experimentation?
Deontologist ethics say that the morality of an action is dependent on a universal rule. So if there is a pre-existing, universal rule that experimenting on animals is wrong, then it is wrong full stop.
What are the six concepts in animal pain research?
Expose animals to cold, heat, electric shock, or mechanical stimulus and measure thresholds; inject chemicals and measure the behaviours that result from it; and measure spontaneous pain.
