Transcript Pain - ISpatula

Dealing with Pain and
Fever in the Pharmacy
Pain:
Latin. poena = “punishment”
(reflects the deleterious effects that can be inflicted upon the body)
“ unpleasant sensory and emotional
experience associated with actual or
potential tissue damage, or described in
terms of such damage ”
International Association for the Study of Pain
Mechanism of Perception
of Pain:
The sensory
component of pain
results from
transmission of
peripheral pain
impulses to the CNS
by nociceptors and
nociceptive nerve
fibers.
Mechanism of Perception
of Pain:
Afferent pain impulses
Through the dorsal
route ganglion
Synapse with
Ascending fibres
to the brain
dorsal
horn of
spinal cord
Efferent fibres to the
periphery- complete
the circle
Many substances involved
e.g. Substance P, bradykinin, histamine, prostaglandins
Mechanism of Perception of
Pain:
normally a balance exists between
excitatory and inhibitory
neurotransmissions
Perceived pain, either acute or chronic
occurs when this balance changes,
resulting in exaggerated responses and
sensitization
Pain
due to
Noxious stimuli
(e.g.mechanical, thermal)
Acute
(immediate)
“fight-or-flight”
epinephrine
release
Ongoing tissue
damage/diseases
Release of pain-facilitating
mediators: prostaglandins,
histamine, bradykinen
Chronic
Pain Classifications
Acute:
•
•
•
•
Duration of 0 to 7 days.
The cause may be known or unknown.
usually occurs as part of a single and treatable event.
a result of traumatic injury, surgical procedure, or a
medical disorder.
• often (not always) associated with autonomic nervous
system responses (tachycardia, hypertension, diaphoresis).
• decreases with time.
• Examples of diagnoses that are associated with acute pain
include: fractured femur, appendicitis, burns, procedural
pain.
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Acute exacerbation of a recurring painful
condition:
Pain can occur over any duration of time.
Pain is due to chronic organic
nonmalignant pathology. Examples of
diagnoses that include acute exacerbation
of a recurring painful condition are the
following: sickle cell pain episodes and
migraine headache. There are pain-free
episodes between the exacerbations.
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 Chronic/persistent pain: Chronic (persistent) pain is pain that lasts
longer than the expected time of healing. There is continuous pain
or the pain recurs at intervals for months or years. In some cases,
there are acute exacerbations of chronic pain problems. The cause is
often unknown. Examples of chronic/persistent pain include the
following: low back pain, diabetic neuropathy, post herpetic
neuralgia, multiple sclerosis, and phantom pain.
 Cancer pain: Pain caused by “conditions that are potentially life-
threatening.” The causes of cancer pain are: cancer itself, treatment
of cancer and concurrent disease. Examples of cancer pain include
the following: cancer of the pancreas, spinal cord compression
caused by tumor infiltration, postsurgical pain associated with cancer
treatment, post mastectomy syndrome.
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Management of Pain:
Acute and chronic malignant:
- indications for aggressive drug therapy.
- Take analgesics on a regular basis to
prevent the recurrence of pain not “as
needed” > “i-e after the pain recurs”
- Sometimes additional mechanisms are
involved- inflammation > NSAID
Management of Pain:
Chronic non-malignant pain:
- Analgesics: NOT the primary treatment, only
adjuncts.
- The underlying disorder should be treated,
not just the presenting symptom
- Multi-modal approach: a doctor with pain expertise
(anaesthiologist, neurologist), rehabilitation specialist
(physiotherapist), mental health professional (psychologist) and
a pharmacist.
Types of Pain
Somatic
Visceral
Neuropathic
Pain of all three
types can be
either acute or
chronic.
Pain-associated conditions
responsive to OTC analgesics:
Headache
Myalgia
Periarticular pain
Arthralgia
Headache:
A symptom: primary or
secondary
Results from dysfunction, injury or
displacement of pain-sensitive cranial
structures.
Headache
Muscle contraction.Tension HA
Vascular HA / Migraine
Other Types of HA
Vascular/ Muscle Contraction HA
Traction HA
e.g. Side effect, sinus HA,
eye strain, dental pain
Chronic daily HA (medication
overuse)
Headache:
1. Muscle Contraction / Tension HA:
-
Results from tight muscles at upper back, neck, occiput
or scalp.
-
Bilateral, diffuse- at top of head- extend. Aching ‘tight’
pressing- gradual in onset, worsens through the day.
-
Associated with emotional stress/anxiety- may last
several days (Acute or chronic)
-
  OTC analgesics for acute types
-
Chronic types: physical therapy + relaxation
NOTE
Recently, neurological research has
isolated the temporalis muscle as the
primary center of tension headache
pain and possibly common migraine
pain (Boyd, 2005)
2. Migraine HA (vascular HA)
-
Mainly women (3 times more)
Attack: 3 hrs--- up to 3 days (av. 24 hrs)
Migraine: recurrent, hemicranial, throbbing
Triggers: stress, fatigue, oversleeping,
fasting, vasoactive substances in food,
caffeine, alcohol. Menses and changes in BP;
- Maybe caused by medications: nitrates, OCPs,
indomethacin, HRTs)
- International headache society: recognises 7
types of migraine BUT for practicality
classical OR common
Classic Migraine (with aura)
Accounts for < 25% of migraine cases
visual or neurological aura
 over 5-20 minutes and can last for up to 1
hour
Within 60 min of aura ending HA starts
Pain unilateral, throbbing, moderate to
severe, sometimes generalized and diffuse.
Physical activity and movement intensify
pain. Nausea (1/3 sickness). Photophobia,
Phonophobia, fatigue, concentrating difficulty.
Common Migraine
(without aura)
75% of sufferers
No aura
All other symptoms the same
3. Cluster headache
Predominantly affects men aged 40-60
HA occurs same time each day, last 10 min-3h
50% of patients: night-time
Woken 2-3 h after sleep with steady intense unilateral
orbital pain.
Conjunctivitis and nasal congestion (watery) is
experienced at same side of head as HA
Ch.ch: periods of acute attack, typically a number of
weeks- few months (1-3 attacks per week)
Nausea is usually absent and family history uncommon
Referral to the doctor. OTC unlikely to be effective
4. Vascular- Muscle contraction HA:
-
-
Patients with daily tension headaches and occasional
migraines
Either type can precipitate the other
5. Other Causes of HA
**Sinus Headache:
- infection/blockage of the paranasal sinuses >
-
inflammation/distension of the sensitive sinus walls.
Localised: peri-orbital, forehead area
with stooping, blowing nose. Upon awakening,
subside after a while
OTC analgesics + decongestants
Persistent > bacterial infection> Dr.
Headache:
- All secondary causes of HA except sinusitis
need to be referred.
- Fever, hangover, some NSAIDS (like what?)
- eye strain, infection (e.g. meningitis),
depression, anxiety, glaucoma > OTC not
effective
- Temporal arteritis, raised ICP
- ‘weekend’HA
Secondary HA:
Glaucoma: frontal HA with pain in the
eye.
Sometimes, but not often, the eye
appears red and is painful. Vision is
blurred and the cornea can look cloudy.
In addition, the patient may notice
halos around the vision.
Secondary HA:
Meningitis: severe generalized HA associated
with fever, an obviously ill patient, neck
stiffness, a positive kernig’s sign (pain behind
both knees when extended) and latterly a
purpuric rash all classically associated with
meningitis
Meningitis is notoriously difficult to diagnose. Any child has a
difficulty in placing the chin on the chest, has a headache and is
running a temperature over 38.9 ̊C Referred urgently
Meningitis
When to Refer?
HA unresponsive to analgesics
HA in children < 12 y/o with stiff neck or skin rash
HA occurs after recent (1-3 months) trauma injury
HA that lasted for > 2 weeks
Nausea and/or vomiting in the absence of migraine
symptoms
Neurological symptoms (in absence of migraine)
especially change in consciousness
New or severe HA in patients over 50
Symptoms indicative of cluster HA
Very sudden or severe onset of HA
Myalgia
Dull, constant diffuse pain of the muscles cause by:
Systemic infection
(e.g. infuenza, measles)
Strenous exersion
Prolonged tonic contraction
(e.g. exercise, poor posture)
• OTC analgesics should be started soon after the injury.
Adjunctive: heat, massage.
• Remobilisation after injury healed is important,
otherwise: weak, tight, overly contracted muscles, trigger
points may arise
•R.I.C.E: beneficial. ice, vapo-coolant spray, trigger point
injections (= Local anaesthetic to facilitate mobilisation)
Periarticular Pain:
injury or inflammation to the tissues
surrounding the joint ( joint capsule,
ligaments, tendons, bursae)
Localised tenderness, pain associated with
movement of structure. knee, shoulder, elbow
Responds well to OTC analgesics
and limitation of movement
Arthralgia:
Joint pain often caused by synovitis
(inflammation of synovial membrane). Cartilage
loss may occur (e.g. in DJD, RA).
• Osteoarthritis (DJD)
• Reumatoid Arthritis (RA)
-In wt bearing joints:
hips, knee, lumbar spine
-mainly: multiple joints, fingers,
hands, wrist and feet
-Paracetamol is analgesic
of choice, wt loss
- joints warm, red, swollen,
-For acute flares: NSAIDs,
local heat
-more than OTC (NSAIDs):
education, physical therapy,
motion limited > deformity
Pain
Assess the patient's level of pain or
discomfort.
Doctor/Pharmacist should enquire
about:
-
Aetiology
Duration
Location
Severity
Factors that or pain
Acute Pain
“The Patient’s Pain
Is What They Say It Is”
Measuring Acute Pain
Adults

Verbal Rating Scales
 None

Mild
Severe
Numerical Rating Scales
 0 = no pain

Moderate
10 = worst pain ever
Visual Analogue Scales
Measuring Acute Pain
Children 3-7 yrs
Assessment of Pain:
It is important to use validated scales
for pain assessment:
Visual Analogue
Scale (VAS):
marking on a 10cm
line distance that
represents pain,
measure then record
1-100
Verbal numerical
rating scale
0----------10
Treatment of Pain
Fever
Fever is defined as a body temperature
that is higher than the normal core
temperature of 37.8ºC (average 36.4 ºC
–37.2 ºC )
Rectal > 38.8 ºC
Oral >37.8 ºC
Axillary > 37.2 ºC
Complications of Fever:
Serious complications are rare
Harmful effects: dehydration,
delirium, seizures, irreversible
neurologic/muscular damage and coma
If
> 41.1ºC
However, even lower temp can be lifethreatening: infants, people with heart D, brain tumor or
haemorrhage, CNS infections, preexisting neurologic disorder
>> febrile seizures
Febrile Seizures:
seizures associated with fever in the
absence of another cause (e.g. acute
metabolic syndrome, CNS inflammation)
in 2-4% of children (6mths-5
years)
• Simple
• Complex
-No longer than 15 mins
-> 15 mins
- do not recur during single
episode
- repetitive during the episode
- no focal features
- in children of
-No neurologic sequelae
- exhibit focal features/signs
preexisiting/latent epilepsy
Febrile Seizures:
although magnitude and rate of temp are
determinants of febrile seizures, however, the
temp at which the child will seize is
unpredictable.
high risk: previous seizure, family Hx,
documented CNS disorder.
Prophylaxis: antiepileptics (DOC: valproate,
diazepam) are reserved for those at high risk.
Prevalence of epilepsy may be higher after a
febrile seizure.
Measurement of body temperature
Measurement of body temperature
Axillary, tympanic, oral, rectal
-
During the course of illness > use same thermometer
wash hands thoroughly before and after
Types of thermometers:
Mercury-in-glass
Electronic thermometer
Tympanic thermometer
Skin thermometer
Types of thermometers:
oral ~ bulb: thin, long to reach well
under tongue
rectal ~ bulb: short, thick, permit
insertion with little risk of breakage
rectal ~ can be used orally
Never the opposite (why?)
Never use the same thermometer for
both oral and rectal measurements
Treatment of Fever:
Fever is a sign of an underlying process
Treatment should focus on the underlying
cause instead of temperature reading
no correlation between magnitude/pattern of
temp elevation (persistent, intermittent, recurrent,
prolonged) and the aetiology or severity of the
disease
Thus, it is difficult to determine the cause of
fever based solely on temperature elevation
The main indication for treatment
of fever is:
 Patient discomfort
Arguments against treatment of
fever:
1. The benign and self-limited course of fever
2. The possible elimination of a diagnostic or
prognostic sign
3. The untoward effects of antipyretic drugs
4. Fever is not associated with harmful effects
unless temperature exceeds 41.1 ° C
5. The attenuation of enhanced host defenses
(i.e. possible therapeutic effects of fever)
Arguments against treatment of
fever:
An evidence: fever is an adaptive
response & elevated body
temperature maybe beneficial:
A. certain microbes may be thermolabile,
growth is impaired by higher-than-normal
temperature
 Clinical evidence: treatment of chickenpox
with paracetamol, or rhinovirus with ASA:
resulted in longer duration of symptoms
than no treatment
B. Low grade fever may also have
beneficial effects on host defense
mechanisms
(e.g. antigen recognition, T-helper
lymphocyte function, leukocyte motility)
- But these effects have not been shown to
favorably alter the course of infectious
diseases
Treatment Goals
The major goal of self-treatment is to
alleviate the discomfort of fever by
reducing the body temperature to a
normal level
General Approach: antipyretic
around the clock and continued for at
least 24 hours + nonpharmacologic
measures
Exclusions for self-treatment of
fever:
1.
2.
3.
4.
5.
6.
7.
patients > 3 months old with rectal temperature ≥
40 ° C
children < 3 months old
Symptoms of infection
impaired O2 utilization (e.g. severe COPD,
respiratory distress, heart failure)
Impaired immune function (e.g. cancer, HIV)
CNS damage (e.g. head trauma, stroke)
Children with Hx of febrile seizures or seizures
Non-pharmacologic:
- light clothing, remove blankets, room
temp (25.6° C)
- increase fluid supply (by at least
1oz/hour)
- if > 40° C- sponging with tepid water, 1
hour after antipyretic intake
Not recommended in children < 40 ° C (why?)
Treatment of Fever:
children predisposed to seizure:
- The doctor should be contacted at the 1st
sign of fever
- Antipyretic should be given every 4 hours
with one dose during the night
- Anticonvulsants given by the doctor
- If febrile-seizure occurred  sponge with
tepid water