Week 11: Acute Pain

Question 1

Pain increases ?

Answer 1

• sympathetic output
• Increases myocardial oxygen demand
• Increases BP, HR

Question 2

problems with pain decreasing mobility

Answer 2

• Increases risk for DVT/PE
• Increases risk for pneumonia, atelectasis secondary to splinting

Question 3

Pain assessment

Answer 3

• Intensity: pain scale, and pain level you could function at
• Location
• Onset
• Duration
• Radiation
• Exacerbation
• Alleviation

Question 4

Acute Pain

Answer 4

• Brief duration, goes away with healing, usually 6 months or less.
• Not necessarily more severe than chronic
• May be sudden onset or slow in onset
• Examples are broken bones, strep throat, and pain after surgery or injury

Question 5

Chronic Cancer Pain

Answer 5

• Pain is expected to have an end, with cure or with death.
• Aggressive treatment
• Addiction not a concern

Question 6

Chronic Non-Malignant Pain

Answer 6

• Pain has no predictable ending
• Difficult to find specific cause
• Often can’t be cured
• Frequently undertreated

Question 7

Nociceptive

Answer 7

• caused by activation of pain receptors in the body. It can be divided into somatic pain and visceral pain.
• Somatic: Somatic pain is usually characterized as sharp and well-localized and related to pain in skin, soft tissue, muscle or bone.
• Visceral: pain is generally more vague and related to activation of pain receptors in the visceral organs like the kidney or liver

Question 8

-Neuropathic pain

Answer 8

• often characterized as burning, shooting, tingling or electric. It is related to abnormal functioning of sensory nerves (i.e. by transection, compression, etc.)
• damage to sensory nerves

Question 9

Categories of pain by type: Somatic

Answer 9

• Source: Skin, muscle, and connective tissue
• Examples: Sprains, headaches, arthritis
• Description: Localized, sharp/dull, worse with movement or touch
• Pain med:Most pain meds will help, if severe, need a stronger medication

Question 10

Categories of pain by type: Visceral

Answer 10

• Source:Internal organs
• Examples: Tumor growth, gastritis, chest pain
• Description: Not localized, refers, constant and dull, less affected with movement
• Pain Med: Stronger pain medications

Question 11

Categories of pain by type: Bone Pain

Answer 11

• Source: Sensitive nerve fibers on the outer surface of bone
• Examples:Cancer spread to bone, fx, and severe 0steoporosis
• Description:Tends to be constant, worse with movement
• Pain Med: Stronger pain meds, opiates with NSAIDS as adjunct
• Will need nonsteroidals with their opiates

Question 12

Categories of Pain by Type: Neuropathic

Answer 12

• Source: Nerves
• Examples:Diabetic neuropathy, phantom limb pain, cancer spread to nerve plexis
• Description:Burning, stabbing, pins and needles, shock-like, shooting
• Pain Meds:Opioates+tricyclic antidepressants or other adjuvant
• Opioids, neurontin

Question 13

Rule of thumb common sense rules for treatment of pain

Answer 13

• Use the lowest effective dose by the simplest route.
• Start with the simplest single agent and maximize it’s potential before adding other drugs.
• Use scheduled, long-acting pain medications for constant or frequent pain, with prn, short-acting medication available for breakthrough.
• Treat breakthrough pain with one-third the 12 hours scheduled dose.
• If three or more prn doses are used in a day, increase the scheduled dose. Increase by ¼ - ½ of the prior dose. Increase the prn dose when you increase the scheduled dose.
• Be vigilant at assessing the side effects of medication. Treat or prevent side effects, such as constipation and nausea. Change medication as necessary.
• Use the WHO’s step-wise approach, also called WHO Analgesic Ladder, Subsection 2.7 in Manual.
• Reevaluate and adjust medications at regular intervals and as necessary.
• Do not stop pain medication in terminal patients. Change the route if needed.

Question 14

multimodal analgesia

Answer 14

• Several analgesics with different mechanisms of action, each working at different sites in the nervous system
• Acetaminophen
• Non-steroidal anti-inflammatory drugs (NSAIDs)
• Opioids
• Anticonvulsants
• Antidepressants
• Local anaesthetics
• NMDA Antagonists
• Non-pharmacologic methods
• Lower doses of each drug can be used therefore minimizing side effects
• With the multimodal analgesic approach there is additive or even synergistic analgesia, while the side-effects profiles are different and of small degree

Question 15

opioid efficacy is limited to side effects

Answer 15

• The harder we “push” with single mode analgesia, the greater the degree of side-effects
• Ex: There is no single silver bullet. With many patients, especially knee arthroplasty and shoulder repairs, it is not possible to achieve satisfactory analgesia devoid of side-effects that both pose a risk to the patient and also slow down the recovery process, ie. Sedation, slow progress in rehab.

Question 16

Opioids

Answer 16

• Potent analgesics
• Drug of choice for moderate to severe pain
• Unfortunately, they are often the only drug ordered
• Side effects:Sedation, nausea, decreased bowel motility, urinary retention, pruritis, respiratory depression, etc.
• 10 fold variability between patients
• All opioids have same side effects but efficacy:side effect ratio is different for everyone
• Stick with what works and keep it simple
• Always by mouth if possible
• Avoid pro-drugs ie. codeine
• Avoid combo preparations

Question 17

Equianalgesia

Answer 17

PO vs.

Morphine: 10 mg
Codeine:~ 60-100mg (4-fold variability)
Hydromorphone:2 mg
Oxycodone:5 mg

Parenteral

Morphine: 5 mg
Codeine: N/A
Hydromorphone: 1 mg
Oxycodone: N/A

Question 18

naloxone (narcan)

Answer 18

• Mu opioid antagonist
• Dilute 1 mL of naloxone 0.4 mg/mL (ie. one vial) with 9 mL of NS for a total of 10 mL of solution and a final concentration of 0.04 mg/mL
• Administer 0.04 mg at a time until reversal of respiratory depression has been achieved, ie. when they’re sitting up awake and talking to you!
• Half life of 30 minutes while opioids have a half life of 2 hours

Question 19

pain management in the elderly

Answer 19

_ Elderly present several pain management problems:_

• Little attention in the literature for physicians or nurses on topic of pain in the elderly.
• Elderly report pain differently due to changes in aging-physically, psychologically, culturally.
• Institutionalized elderly often stoic about pain.
• Cognitive impairment, delirium, and dementia present barriers to pain assessment.
• Pronounced effect therefore, lower doses
• Cognitive dysfunction is a major issue
• Organ dysfunction/insufficiency affects metabolism
• Interaction with other medications, increased incidence of polypharmacy
• Opioids produce higher plasma concentrations in older persons
• Greater sensitivity in both analgesic properties and side effects
• Smaller starting doses required
• Consider duration of action, formulation availability, side-effect profile, and resident preference.
• Review for drug interactions

Question 20

opioid use in elderly pain control/fentanyl patch

Answer 20

• Older persons may have fluctuating pain levels and require rapid titration or frequent breatkthrough medication.
• Long-acting are generally suitable once steady pain levels have been achieved.
• Once steady pain relief levels are achieved, controlled-released formulas can be used.
• Fentanyl patches should not be placed on areas of the body that may receive excessive heat. Patches may be contraindicated with exceptionally low body fat.

Question 21

pediatric pain

Answer 21

• Often under-treat children’s pain
• When initiating pain medications, consider a standing regimen
• Avoid combination products (i.e. Vicodin) at first
• Constantly re-assess your pain plan
• Infants: Face, Legs, Activity, Cry, Consolability (FLACC)
• Verbal Children: Scale of 1-10 (may use faces and/or numbers), Non-verbal clues

Question 22

FLACC

Answer 22

Face, legs, activity, cry, consolable. Scale of 0-2. 0 no reaction, usually calm, 2 is really reacting/acting out

Question 23

Acetaminophen for pediatric patients

Answer 23

• PO: 10-15 mg/kg every 4-6 hours
• PR: Loading dose 35-50 mg/kg; Maintenance dose 20 mg/kg every 6 hours
• NO MORE THAN 5 DOSES in 24 hours

Question 24

Ibuprofen in peds

Answer 24

• PO: 5-10 mg/kg every 6-8 hours
• MAX 40 mg/kg/day
• Contraindicated in active GI bleeding, hypersensitivity to NSAIDs
• Caution in severe asthmatics

Question 25

Ketorolac in peds

Answer 25

• NSAID
• Available PO, IV, IM
• Potential opioid sparing effect
• Cannot be used for a long time
• No more than 24-72 hours in children less than 2 years
• No more than 5 days in children 2 and older

Question 26

Morphine in peds

Answer 26

• PO: 0.2-0.5 mg/kg every 4-6 hours
• IV: 0.05-0.2 mg/kg every 2-4 hours
• PCA: 0.015 mg/kg/hr basal with 0.015 mg/kg PCA dose q10 min lockout

Question 27

oxy, fentanyl, hydromorphone in peds

Answer 27

Oxycodone

• 4-5 hour duration

Fentanyl

• Potent (100x morphine), short duration
• Transdermal patch has long onset and long acting (2-3 days)

Hydromorphone

• 5x more potent than morphine
• 4-6 hour duration

Question 28

Addiction

Answer 28

*Primary, chronic, neurobiologic disease, with genetic, psychosocial, and environmental factors influencing its development and manifestations.

*Characterized by behaviors that include one or more of the following:

• impaired control over drug use
• compulsive use
• continued use despite harm
• craving

Question 29

Incentive sensitization

Answer 29

• Casual use sensitizes reward system
• high motivation to repeat rewarding behaviour for pleasurable experience

Question 30

Hedonic allostasis

Answer 30

• Chronic exposure and production of stress factors and negative emotional state, withdrawal and anxiety
• Use to avoid negative-affect state

Question 31

Positive reward

Answer 31

• Reward system responds – corticotropic releasing factors and stress factors reduced

Question 32

End of drug salience

Answer 32

Dopamine reward threshold increases, pleasure decreases

Question 33

Drug use based on negative affect and stress

Answer 33

Modulation of withdrawal, stress and anxiety

Question 34

Physical dependence

Answer 34

State of adaptation that is manifested by a drug class-specific withdrawal syndrome that can be produced by abrupt cessation, rapid dose reduction, decreasing blood level of the drug, and/or administration of an antagonist

Question 35

tolerance

Answer 35

• The body’s physical adaptation to a drug:
• Greater amounts of the drug are required over time to achieve the initial effect as the body adapts to the intake

Question 36

pseudo addiction

Answer 36

• Term used to describe patient behaviors that may occur when pain is undertreated
• May become focused on obtaining medications, “clock watch,” seem inappropriately “drug seeking.”
• Illicit drug use and deception can occur in the patient’s efforts to obtain relief
• Distinguished from true addiction in that the behaviors resolve when pain is effectively treated.

Question 37

NSAIDS

Answer 37

• Work at site of tissue injury to prevent the formation of the nociceptive mediators Prostaglandins
• Can decrease opioid use ~30% therefore decreasing opioid-related side effects
• Minor surgeries can use NSAIDs instead of opioids to completely eliminate opioid-associated side effects
• Side effects: GI upset, gastric ulcers, decrease renal medullary blood flow, reversible inhibition of platelet function
• Newer NSAIDS selectively (primarily) inhibit cyclooxygenase-2 (COX-2) which is induced by surgical trauma with minimal effect on COX-1 which is responsible for GI and platelet side effects
• Celecoxib (Celebrex)

Question 38

neuraxial techniques: who gets them

Answer 38

Patient factors: Low pain tolerance, opioid tolerance, Sleep apnea, Narcolepsy, Obesity, COPD, Cardiac disease, Elderly – those at risk for post-operative cognitive dysfunction

Epidural Infusion:

• Used for major surgery ie. oncologic TAH BSO, thoracotomy
• Ideally placed pre-operatively and used in combination with a GA for surgery and continued ~ 2 days
• Usually patient is tolerating diet and ambulation to chair when epidural is D/C

Question 39

ideal epidural infusions

Answer 39

• When placed at the level of the incision and with a constant infusion of LA and opioid:
• Minimal or no pain at all, particularly with movement
• No motor block: Can ambulate
• Speedier return of bowel function: With more LA and less opioid –Cochrane review 2003
• Less nausea
• Less sedation
• Less delerium
• Do not require supplemental IV opioids and associated side effects
• Less pulmonary complications: Quicker extubation, better oxygen saturation, less pneumonia

Question 40

side effects of epidural

Answer 40

Hypotension

• LA causes a sympathectomy which leads to vasodilatation
• Mild volume depletion, which can normally be compensated for with vasoconstriction, will be unmasked with an epidural
• Pts require adequate volume status with an epidural
• Pts will initially c/o dizzyness, lightheadedness and nausea when sitting up or standing
• Can document orthostatic hypotension
• Will then progress to supine hypotension if not corrected
• Major problem POD #1 when 3rd spacing still occurring, minimal IV fluids infusing and pt NPO

Leg weakness or numbness

• Can occur if catheter is too low (low thoracic or lumbar) or if it is one-sided
• Inhibits ambulation and distressing to pt therefore must be fixed
• Infusion can be adjusted or catheter pulled back
• *Must be addressed as this is the first sign of epidural hematoma leading to permanent paralysis*

Post dural puncture headache 1:100

• Only if dura is unintentionally punctured
• More likely in younger people

Infection

• Some reports of epidural abscess as high as 1:1900
• Usually just superficial skin infections
• Increased risk in immunosuppressed

Epidural hematoma

• Most feared complication
• Incidence of 1:180 000 – 1:220 000: Increased with heparin, age, gender, ASA, NSAIDs, traumatic placement, spinal stenosis
• Leg weakness, numbness and bladder/bowel disturbance are first signs
• If not evacuated within 8-12 hours, usually leads to permanent paralysis

Question 41

risk factors for epidural hematoma

Answer 41

• Abnormal coagulation
• Elderly
• Female
• Debilitated patients
• Traumatic insertion
• Unknown spinal pathology

Question 42

anticoagulation and epidurals

Answer 42

• ASA – OK
• NSAIDS – OK
• UFH 5000 sc bid – OK if no other antiplatelets
• UFH 5000 sc tid – sort of OK, but not really (according to ASRA)
• LMWH (Dalteparin)– increased risk – not really OK
• IV heparin – not OK
• Clopidigrel, ticlodipine – not OK
• Coumadin – not OK

Question 43

local anesthesia

Answer 43

Qball

Question 44

non-pharm interventions for pain

Answer 44

• Massage therapy:This may help relax tight muscles and decrease pain.
• Physical therapy: This teaches you exercises to help improve movement and strength, and to decrease pain.
• Aromatherapy: This is a way of using scents to relax, relieve stress, and decrease pain. Aromatherapy uses oils, extracts, or fragrances from flowers, herbs, and trees. They may be inhaled or used during massages, facials, body wraps, and baths.
• Laughter: Laughter may help you let go of stress, anger, fear, depression, and hopelessness.
• Music: This may help increase energy levels and improve your mood. It may help reduce pain by triggering your body to release endorphins. These are natural body chemicals that decrease pain.