Chronic Pain & Drug Therapy – Pharmacology

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Chronic Pain & Drug Therapy – Pharmacology

This quiz is about chronic pain and drug therapy of pharmacology.


Visceral Pain

Arises from internal organs
Deep aching or sharp stabbing pain


Neuropathic Pain

Arises from injury to nerves
Burning, shooting, stabbing
Abnormal pain processing
Makes difficult to treat


Types of Pain

Acute
Chronic
Caner Chronic Pain
Chronic Non-Cancer Pain


Acute Pain

Short duration (< 3-6 months)
Identifiable cause
Acute pain ↓ as healing occurs
Severity of pain equals acuity of the injury or disease process
Specific & localized in nature
Drugs usually work
Sympathetic nervous system response
Fight or Flight Response
hypertension, tachycardia, restlessness, anxiety, diaphoresis/pallor, urinary retention, anxiety/agitation/confusion


Chronic Pain

Caner Chronic Pain
Chronic Non-Cancer Pain
Pain lasts > than 3-6 months.
Sometimes identifiable cause
Pain severity > stage of the injury or disease
Often periods of waxing and waning
Requires more and more drug therapy
Persists beyond healing stage
NO sympathetic nervous system responses.
Depression, irritability, flat affect, fatigue, decrease physical activity, withdrawal


Characteristics of Pain
Acute

Mild to severe
Sympathetic NS response
Related to tissue injury
Restless and anxious
Reports pain
Behavior indicative of pain


Chronic

Mild to severe
Parasympathetic NS response
Continues beyond healing
Depressed and withdrawn
Does not mention pain
unless asked
Pain behavior often absent


Pain Relief

Endorphins
Morphine-like substance
Able to “close the gate”


Gate Control Theory

Theory about how pain is transmitted and blocked
Proposes that only one pain pathway (gate) is open at one time. The brain therefore does not perceive pain while it is preoccupied with other sensory input.
Explains how massage, vibration, heat, and cold reduce pain sensations
Melzack & Wall, (1965)


When should you assess for pain?

on admission
pain is the 5th vital
at all encounter with pt
be alert for pain
identify pt at risk
for pain
Don’t wait to be told


Pain Assessment
PQRST

PQRST
Provoking factors
Quality
Region or radiation
Severity or intensity
Time


Pain Assessment
COLDERR

Character
Onset
Location
Duration
Exacerbation
Relief
Radiation


Pain Assessment
OLDCART

Onset
Location
Duration
Characteristics
Agravating
Relieving
Treatment


Why Use a Pain Scale ???

Quantify data with a number
Maintain consistency between ratings
Make the data objective
Note: Some facilities may make it policy to use one or more particular scales


Non-Verbal Pain Assessment

Observe the patient for 3-5 minutes
Behavioral Pain indicators
Facial Expressions
Vocalizations
Behavior changes


American Geriatric Society Panel On Persistent Pain In Older Persons

Identified 6 common pain indicators
Facial expressions of grimacing, 1.crying
2.Verbalizations
3.Body movements
4.Changes in interpersonal interactions
5.Changes in activity or routines
6.Mental status changes


Psychosocial Aspects of Pain

Meaning of pain to patient and family
Past experiences with pain
Effect on:
all aspects of all life
daily activities
relationship
enjoyment
family and financial
Spiritual & Cultural


Addiction

Chronic
Many factors influence addiction
Occurs over time
Defined:
Impaired control over drug
Compulsive use
Continued use despite harm and craving


Pseudoaddiction

Addictive Behaviors” because pain is under treated
Anger/esculating demands for more meds
Results in suspicion and avoidance by staff
Common with chronic pain
Behavior resolved when pain is adequately treated


Tolerance vs. Physical Dependence
Tolerance

Tolerance
Repeated use decreases the effect of drug over time
patient need increasing doses to achieve same pain relief.


Physical dependence

Physical Dependence
Results in physical withdrawal symptoms when drug abruptly discontinued, rapid dose reduction or reversal agent given

Occurs in everyone who takes opioids over long period of time


Withdrawal

Important role of nurse is to assess for and prevent withdrawal
Symptoms of opioid withdrawal:
Nausea, vomiting
Abdominal cramping
Sweating
Delirium
Muscle twitching
Convulsions


Substance Abusers

Often result of traumatic injury or health problems that cause pain
Patients with chronic pain medication use should not have medications stopped abruptly
May require higher doses of conventional drugs
Should be identified so appropriate therapy can be prescribed


Placebo Therapy

Only indicated use is in research studies
Need informed consent
Is unethical to administer placebos to your patients


Before Administering Pain Medications

The nurse should:
Assess for drug allergy
Ask patient’s current medications
Assess the patient’s current pain status
Check vital signs


Drug Groups

Non-Opioids
Opioids
Adjuvants


Pain Treatment

Mild (1-3)
Non-opiods
Moderate (4-6)
Weak opioids
Severe Pain (7-10)
Strong opioids

Adjuvants: Can be used at every level of pain


Non-Opioid Analgesics

Most Common
Acetylsalicylic acid (aspirin)
Acetaminophen (Tylenol)
Most are NSAIDs, including aspirin:
Adverse effects: GI disturbances, bleeding
COX-2 inhibitors for long-term use


Opioid Analgesics

Used in management of all types of pain
Work centrally to block release of neurotransmitters in spinal cord
Bind to MU receptors to block release of substance P which prevents the transmission of pain
Most opiods are similar in effect
Response varies widely
Can be administered in many different routes


Opioids

Opioid Agonists: Bind and cause analgesia. By binding to pain receptors they block the transmission of pain to the brain.
Example: Morphine Sulfate
Opioid antagonists: bind to receptors but do not cause analgesia.
Example: Naloxone (Narcan). It is used for overdose, oversedation secondaryto opioids.


Opioids

There is no analgesic dosage ceiling (limit)
Side effects include:
Respiratory depression
Sedation
Constipation
Itching
Nausea & vomiting
Urinary retention
Postural Hypotension
Also have antitussive and antidiarrheal properties


Equalanalgesic Dosing

Not all opioids are the same strength
Morphine sulfate is the gold standard
standard against all other opioids are measured


Weak Opioids

Used for moderate pain and are often found in combination medications
Codeine and Tylenol (Tylenol#3)
Hydrocodone and Tylenol (Vicodin, Loratab)
Oxycodone and Tylenol (Percocet,Tylox).


Strong Opioids

Opioids for moderate to severe pain
Morphine Sulfate
Hydromorphone (Dilaudid)
8 times stronger than morphine
Fentanyl (Duragesic)
IV (acute pain, on pump)
Patches, oral (chronic and cancer pain)
Meperidine (Demerol)
Methadone (Dolophine)-chronic pain or drug dependent patients


Meperidine-Demerol

Synthetic opioid
Toxic metabolite, normeperidine that can cause seizures.
Meperidine half life 2-4 hours
Normeperidine half life 24-48 hours with normal renal function.
Should only be used for a short period of time (2-3 days)


Meperidine Toxicity

-Older adults at high risk
People with decreased renal clearance
Assess patients for complaints of numbness, twitching, confusion and seizures


Professional Role of Nurse:
Ensure Comfort and Safety

Assess for pain
Monitor BP & Respirations prior to administration
Believe the patient
Medicate with appropriate medication
Assess for adverse effects
Expected Outcomes: Pain relief and drowsiness

Sedation occurs before respiratory depression


Respiratory Assessment

Monitor rate and depth of respirations
Especially while sleeping
Severe respiratory depression usually seen with IV administration or in patient with no tolerance to opioids


Treatment for Respiratory Depression

Attempt to arouse patient
Administer opioid antagonist Naloxone (Narcan) IV
Fast acting
Reverses opiod effect
Pain will quickly return
Continue to monitor as effects of respiratory depression will outlast the Narcan and respiratory depression can reoccur


Nursing Interventions to Prevent Side Effects of Opiods

Ongoing assessment for over sedation and respiratory depression
Assess for constipation
Push fluids & encourage ambulation
Administer stool softeners & laxatives as ordered
Nausea & vomiting
Administer antiemetics as prescribed


Routes of Administration
oral

Oral
Preferred route for pain control
Especially chronic
Expect onset in 30 minutes

Long acting and controlled release available
May not be crushed


Routes of Administration
Intramuscular

Intramuscular
Variable absorption rates
Tissue fibrosis and abscess can form after repeated injections
Onset 30-45 minutes
Not recommended for pain control
Intravenous
Onset within minutes
Most efficient


Routes of Administration
Transdermal

Transdermal
Fentanyl (Duragesic)
Long duration of action (48-72 hours)


Rectal Suppository

Absorbed through the rectal mucosa
Many opioids can be administered via this route
Slower onset of action


Sublingual/ Buccal

Sublingual-placed under tongue
Buccal: Fentanyl (Actiq) oral transmucosal system


Intranasal

Butorphanol (Stadol) agonist-antagonist
Sumtatriptan for migraines
Good for out-patient use


PCA

PCA (Patient Controlled Analgesia)
Patient controls delivery of medication
Dosage preset
Advantages
Use less drug
Fewer side effects
Less time for nurse
Vital Signs, pain level,side effects monitored closely


Patient Controlled Analgesia
PCA

Settings: continuous, PCA or continuous with PCA
Example of an order:
Morphine Sulfate
Loading dose 2 mg
0.5mg continuous
PCA dose 1mg
Lockout 6 minutes
4 hour limit: 20mg


Benefits and Risks

Benefits
Empowers patients
Better control of pain
Reduces patient anxiety
Risks
Over sedation and respiratory depression
Drug administration set-up errors
Others besides patients pushing the button


Nursing Responsibilities

Monitor for adverse effects & follow protocols
VS & sedation levels every 2 hours
Assess for other side effects:
-Urinary retention
-Nausea
-Itching
-Consitpation
Educate patients on proper use and what to report
Obtain other pain therapies for patients who cannot administer PCA competently


Adjuvant drugs

Not true analgesics
Work alone or in combination to relieve pain
Enhance or potentate effectiveness of pain relief
Good with chronic pain and complex pain syndromes
Examples
Tricyclic antidepressants
Antiseizure medications
Antianxiety drugs
Corticosteroids


Topical and Local Anesthesia

Topical anesthesia
Local anesthetic infusion pumps: ON-Q Pump


Adjuvant Drugs

Benefits:
-Reduce need for opiods
-Work better for some types of pain
-Treat associated symptoms of depression and sleep disorders with chronic pain


Best Practices for Scheduling of Medication

-Pre-medicate for painful procedures/activities
-Around the clock dosing preferred
–Assess minimum every 4 hours
-Treat pain early for better effect
-Breakthrough dosing for cancer pain
-Follow BRN of CA guidelines


Nonpharmacological Interventions

Cognitive-Behavioral Measures
Alternative Medicine
Complementary Medicine


Cutaneous Stimulation

-Application of heat and cold
-Therapeutic touch
-Vibration
-Massage


Trancutaneous Electrical Stimulation

TENS
Cutaneous electrical stimulation
Usually initiated by PT
Empowers patient and gives some control


Physical Measures

Physical Therapy & Occupational Therapy
Goal to increase function, decrease pain
Methods:
–Splints
–Exercise
–Heat and cold therapies


Pain

#1 reason to seek medical attention


Cognitive-Behavioral Therapy

Distraction
Very effective
Transient, best used with other measures
Guided imagery
Hypnosis
Modify environment
Meditation
Vibration
Music


Alternative Therapies

Acupuncture
Accupressure
Magnet therapy
Aromatherapy


Pain Management In The Elderly Patient

Pain is prevalent in the elderly
At risk for under treatment
Don’t describe the pain as “pain” but may call it discomfort, or soreness
Tend to report less often
May view as sign of weakness or
something to be lived with
Don’t want to be a bother


Assessment Guidelines In The Elderly Patient

Assume pain is present
Ask about present pain only
Use a standard scale
Use a variety of descriptors
ache, sore, hurt
If cognitively impaired assess for non-verbal symptoms of pain


Management of Pain in the Elderly

Use round the clock dosing
Start low and go slow
Monitor for adverse effects
Drug interactions
Avoid use of meperidine (Demerol)
Use nondrug therapies


Definition of Pain

Unpleasant sensory and emotional experiences associated with actual and potential tissue damage
study of pain 1979


Definition of Pain

Whatever the experiencing person says it is, existing whenever s/he says it does.
Margo McCaffery (1968)


Nurse As An Advocate

Primary role of the nurse in pain management is believing their patients.


The Joint Commission Pain Standards

American Pain Society
Pain Care Bill of Rights
Patients have the right to be taken seriously and treated
Have pain assessed and promptly treated
Have ongoing reassessment & evaluation
Treatment modified if not working
Referral to pain specialist for persistent pain


Myth/Misinformation
Contribute to Ineffective Pain Management

Too much pain medication too frequently constitutes substance abuse, causes addiction, will result in respiratory depression or will hasten death
language barrier
comatos pt
baby
dementia
culture


High Risk Population for Under treatment

Infants and children
Older Adults
minorities
cognitive dysfunction
emotional /mental illness
addicts
pt with terminal ill
cultural difference
pt who speaks a difference langugue


Untreated Pain

Physiologic Impact
Quality-of-Life Impact
Financial Impact


ABCs of Pain Management

A-Ask, Assess
B-Believe
C-Choose appropriate medication
D-Deliver the medication in a timely, logical, coordinated fashion
E-Empower the patient


Nurses’ Attitudes/Barriers

Attitudes of health care providers and nurses affect interaction with patients experiencing pain.
Individual experiences with pain
Personal use of meds or Nonpharmacological methods to manage pain
Family’s or SO’s hx or experience with substances for pain control or mood altering effect


Physiology of Pain

Periphery ——>Noxious stimuli


Physiology of Pain

Nociception
Transduction
Transmission
Perception
Modulation


Transduction
Pain Stimulation

Tissue damage—> release of chemicals——> increase excitability and frequency of nerve impulses


Neurotransmitters

Release of multiple substances
Examples
Potassium
Serotonin
Bradykinin
Histamine
substance P
prostaglandins


Transmission

Pain Transmission

To be perceived the pain stimuli must be transmitted first to the spinal cord
Then signals sent to the central areas of the brain


Transmission

Slow or Express Train?

A Delta fiber small, myelinated fibers; send impulses quickly producing sharp, pricking, well localized pain of a short duration.

C Fiber smallest, unmyelinated fibers, send impulses slower producing dull, aching, burning sensations with a diffuse, slow onset of a long duration


Perception

Conscious experience of Pain

Involves several brain structures
Reticular activating system: autonomic response (sympathetic nervous system)
Somatosensory system: localization and characterization of the pain
Limbic: emotional and behavior responses
Cortical: meaning of pain


Pain Tolerance

Pain tolerance: The maximum degree of pain intensity that a person is willing to experience.

Ex: Bad day….stub toe….worst pain ever experienced


Factors Affecting Pain

Age
Gender
Women have more:
pain in women
Headaches
Arthritis, fibromyalgia

Men have more:
Gout
PVD
Back pain
Sociocultural background
Genetics


Physiologic Sources of Pain

Nociceptive —>normal
Neuropathic—>abnormal


Nocioceptic

Normal processing of pain
2 Types Somatic and Viceral
Somatic
Superficial: Skin and tissues (incisions, drains)
Sharp and burning
Deep somatic: Bone, muscle, blood vessels (muscle spasms, orthopedic procedures
Dull, aching, cramping