Pharmacology

Pain Management

Pain Management

• Analgesics relieve pain without producing loss of consciousness or reflex activity

• Should be potent• Should not cause dependence• Should exhibit little adverse effects: constipation,

hallucinations, respiratory depression, N/V• Should not cause tolerance• Should act promptly 7 over a long period w/little

amount of sedation

Pain Management

• Classifications:• Opioid Agonist• Partial Opioid Agonist• Opioid Antagonists• Salicylates• NSAIDs• Misc. Analgesic Agents

Pain Actions

• Pathways to pain tranasmission from the site of injury to the brain for processing & reflexive action

• First step:• Nociceptors– Transduction – Transmission– Perception– modulation

Pain Action

• Nociceptor– Stimulation of receptors at nerve endings (skin,

blood vessel, joints, SQ, periosteum, viscera)– Classified—thermal, chemical, mechanical-

thermal based on type of sensation they transmit

Pain Actions

• Important to Nociceptors is the transduction phase for meds to causing their effects

• Transduction– 1. noxious stimuli causes cell damage with release of

sensitizing chemicals• Prostaglandins• Bradykinin• Serotonin• Substance P• Histamine

– 2. these substances activate nociception and lead to generation of action potential

Pain Actions

• Neurotransmitters role in tranmission of nerve impulses

• Somatostatin• Cholecystokinin• Substance P

Pain Actions

• In the CNS there are 4 pain-transmitting pathways to various areas of the brain for response—opiate receptors– Mu—induce central analgesia, euphoria, dependence,

miosis, resp. depression– Delta—limbic for euphoria– Kappa—responsible for analgesia, sedation, dysphoria– Epsilon-– Sigma (opioid & partial agonists)—autonomic

stimulation, hallucinations, sysphoria

Pain Actions• Blocking chemicals:• Histamine• Prostaglandins• Serotonin• Leukotrienes• Substance P• Bradykinin• Antihistamines—benadryl,• Prostglandins Inhibitors—NSAIDs• Substance P Antagonists—capsaicin• Antidepressants—prolong norepinephrine and serotonin-TCA, SSRI

Pain Actions• Adjunct Agents• Adrenergic

– Norepinephrine– Clonidine

• GABA Receptor Stimulants—block nociceptor activity• Baclofen• Gabapentin• Valproic Acid--block trigeminal neuralgia• Phenytoin• Gabapentin• Caarbamazepine• TCA—inhibit reuptake of serotonin & norepinephrine causing rapid anagelsia• Bisphosphonate—pamidronate effective treating bony metastases

Pain Stepwise Approach

1. Non-opioid +/- Adjuvant—pain persisting or increasing

2. Opioid for mild to moderate pain—pain persisting or increasing

+/- Non-opioid+/-Adjuvant

3. Opioid for moderate to severe painNon-opioid+/- Adjuvant

Pain Recommendations

• Mild acute pain—ASA, NSAIDs, or Tylenol• Inflammatory pain—NSAIDs• Unrelieved moderate pain—moderate potency—

codeine or oxycodone often combination w/Tylenol or ASA

• Severe acute pain—opioid agonist-Morphine, hydromorphone, levophanol

• Severe chronic pain—Morphine sulfate• Other adjunctive—antidepressants or anticonvulsants

—depending on pain cause!

Joint Commission Standards• Primary therapeutic outcomes:• Relief of pain intensity and duration of pain complaint• Prevention of the conversion of persistent pain to chronic

pain• Prevention of suffering and disability associated with pain• Prevention of psychological & socioeconomic

consequences associated with inadequate pain management

• Control of adverse effects• Optimization of the ability to perform ADL’s• Placebo therapy should never be used with pain

management

Nursing Process: Pain Management

• Pain is 5th Vital Sign• Assessed every time VS are taken & recorded• Pain flow sheets• Evaluate pain immediately before and after administration at

1, 2, and 3 hour intervals PO• At 15-30 min intervals after parenteral administration• Data Sheets:• Rating before and after• Nonpharmacologic measures initiated• Patient teaching performed• Breakthrough pain measures implemented

Nursing Process: PM

• Believe patients report• Consider past history, subjective experiences, feelings• Consider psychological, physical and environmental factors—rest, low lighting, quiet,

hydration, back rub, repositioning, hot or cold applications, relaxation techniques, diversion activities

• Be consistent• Tools: • Riley for Infants—face, legs, activity, cry consolability FLACC Scale nonverbal client• Pain Observation Scale—young children 1-4 yrs. POCIS• Modified Objective Pain Score MOPS—children 1-4 yrs. after ENT surgery• Toddler-Preschooler Postop Pain Scale TPPPS—following medical or surgical procedures• Postop Pain Score POPS—infants surgical procedures• Neonatal Infant Pain Scale NIPS—preterm and full-term neonates painful procedures• Wong-Baker– 3 yrs. And older as well as adults with language barriers, who don’t read,

select faces

Nursing Process: PM• Scale 0-101—pulsing, throbbing2—shooting, jumping3—pricking, stabbing, boring4—sharp, cutting, lacerating5—pinching, gnawing, cramping, crushing6—tugging, pulling, wrenching7—hot, burning, scalding, searing8—tingling, itchy, stinging9—dull, sore, hurting, aching, heavy10—tender, taut, rasping, splittingOthers11—exhausting 16—annoying, miserable, intense, unbelievable12—sickening, suffocating 17—spreading, radiating, penetrating,

piercing13—fearful, frightening, terrifying 18—tight, numb, squeezing, tearing14—punishing, cruel, vicious, killing 19—cool, cold, freezing15—wretched, blinding 20—nagging, nauseating, agonizing, dreadful,

torturing

Nursing Process: PM

• How does your pain change with time?• 1. Continuous• Steady• Constant• 2. Rhythmic• Periodic• Intermittent• 3. Brief• Momentary• Transient • What kinds of things relieve your pain?• What kinds of things increase your pain?

Nursing Process: PMLifespan Considerations:Maintain steady blood level of analgesic—best controlADME are affected by ageDosages & frequency increased in children, especially teenager (metabolism)Older Adults smaller dosages (slow metabolism & excretion)Make regular assessments on pain levelContact provider for adjustments in dose & frequency based on responsesBefore initiating pain assessment: assess hearing & visual impairment

Nursing Process: PM Assessment• Medication history

– What meds– How effective– Adverse effects

• Patient’s perception—causes• Believe pain experience• Onset—when pain was 1st noticed, abrupt, occur with eating food• Location--exactly where is your pain• Depth—does sensation spreading out or diffusing, localized• Quality—actual sensation felt like dull, sharp stabbing• Duration—continuous or intermittent, how often• Severity—rate your pain using pain methodology

Nursing Process: PM Assessment

• Nonverbal Observations—body position, facial grimace, immobility of particular part, holding extremity, think about developmental differences--clingy to parents, irritable baby, teens deny pain in front of peers

• Pain relief—specific measure, measure tried, beneficial• Physical Data—always examine affected part for

alterations in appearance, sensational changes, limitation or ROM

• Behavioral Responses—coping mechanisms, manages, crying, anger, withdrawal, depression, anxiety, fear, ADL’s

Nursing Diagnoses

• Acute Pain• Chronic Pain• Urinary Retention• Impaired Gas Exchange• Risk for Constipation

Nursing Process: PM Planning

• History of Pain Experience– Evaluate pain location, depth, quality, duration and severity– Perform baseline VS at least Qshift or more by condition and type of meds

• Pain Relief– Goal of treatment established when initiating regimen, prevention, reduction or elimination,

capacity, QOL, and ability to retain independence• Pain at rest < 3• Pain with movement < 5• At least 6 hrs. of sleep uninterrupted by pain• Able to work at hobby

• Update care plan• Implement nonpharmacologic & pharmacology• During 1st 24 hours reassess often evaluate degree of pain relief provide reassurance• Environmental Control of quiet, little distraction of rest, modify schedules, schedule

diversional activities• Psychological Interventions get staff involve in rest, understanding, providing

diversional activities• Med Administration

– Check degree of pain relief– Keep adequate supply

Nursing Process: PM Implementing• Comfort Measures

– Basic hygiene– Back rubs, massage, hot/cold application– Support affected part, give med in advance

• Exercise and Activity– Moderate if not contraindicated

• Non-pharmacologic Approaches– Relaxation– Visualization – Meditation– Biofeedback– TENS

• Medication– Request pain meds– Encourage open communication– PCA

• Pain Control– Anticipate their need

• Nutritional Aspects– Eat well balanced diet high in B-complex, vitamins, limit or eliminate sugar, nicotine,

caffeine, alcohol, 8 glass of water daily

Education and Health Promotion• Orient client, family & significant others to benefits of adequate pain

control• Work with them to determine perception of pain management, use of

drug & non-pharmacologic approaches• Stress addiction is not a major factor with short-term use• With long term use is to obtain sufficient pain control to ensure comfort• Teach what meds are available• Teach how and when to request them• Discuss patient expectations• Ask what level of exercise is attainable without severe pain• Assess changes in expectations• Constantly report duration and intensity to provider• Assist with effective coping• Teach self-administration• Make sure family understand how to obtain assistance

Education and Health Promotion

• Fostering Health Maintenance– Discuss med information– How it will benefit– Combination of meds & comfort measures, relaxation, meditation, stress reduction,

meeting total care needs to ensure ADL’s– Provide important information– Health teaching of adverse effects– Seek cooperation & understanding of:

• Adherence• Name of Meds• Dosage• Route• Times• Common & Serious Adverse effect

• Written Record– Frequency of attack– Activity performed– When– Techniques used for control– Degree of relief

Drug Class: Opiate Agonist• Opiate Agonists—naturally occurring semisynthetic and synthetic drugs

– Relieve severe pain without loss of consciousness– Stimulate opiate receptor in CNS– Produce physical dependence– Prolonged use produce tolerance or psychological & physical dependence (addiction)

• Uses: relieve acute or chronic moderate to severe pain…injury, postop, renal or biliary, MI or cancer

• Perform neurologic assessment: orientation, alertness, hand grip, motor function

• Take VS hold if RR < 12/min• Check prior analgesics• Check bowel sounds and consistency of stools• Review voiding pattern & urine output• CAE: lightheaded, dizziness, sedation, confusion, orthostatic hypotension, N/V,

constipation• SAE: respiratory depression, urinary retention, abuse• Interactions CNS, Dilantin, Tegretol, SSRI—tramadol, warfarin

Class: Opiate Partial Agonist• Nubain, Talwin, Stadol…etc.• Depends of previous agonist administration• Potency 1st few weeks similar to Morphine• Prolonged use tolerance• Increasing dose doesn’t produce increase analgesia but increase adverse effects—

ceiling effect• Will induce withdrawal in those addicted to agonist opioids• Uses: short term relief up to 3 wks of moderate to severe pain in cancer, burns, renal

colic, preop, obstetric• Outcomes: relief of intensity & duration, conversion of persistent pain, prevention of

suffering, control adverse effects, ADL’s• Perform baseline neurocheck: orientation, mental alertness, hand grip, motor

functioning• Take VS• Check bowel sounds and prior opiate agonist use• Review voiding pattern & urine output• CAE: clamminess, sedation, sweating, dizziness, N/V/dry mouth, constipation• SAE: confustion, disorientation, hallucination, respiratory depression, Abuse

Class: Opiate Antagonists

• Naloxone pure because it has no effect on its own other than reverse CNS depressant

• Withdrawal in addicted clients of agonists• Added to Talwin to reduce abuse by blocking euphoria• Choice treatment for reversal of respiratory depression• Neurocheck: orientation, LOC, hand grip, motor functioning• VS: BP, HR, RR at frequent intervals• Check prior dependence of agonists• Have supportive equipment available• Check bowel sign. Review voiding & urine output• CAE: apathy, N/V, anorexia, mental depression

Drug Class: Salicylates• Most common used• Relief of slight to moderate pain• Analgesic, antipyretic, anti-inflammatory• Inhibit formation, production of S/S of inflammation, synthesis &

release of prostaglandins• Combination effects as choice drug for above• Can be taken long term without dependence• Inhibition of platelet aggregation by blocking thromboxane A2

• Enhances bleeding time• Reduce risk of recurrent TIAs or stroke, MI with previous episodes• Outcomes: reduced pain, inflammation, eliminate fever,

antiplatelet

Drug Class: NSAIDs

Drug Class: Misc Analgesics• Acetaminophen—Tylenol• Synthetic non-opiate analgesic• Works by prostaglandin inhibition in CNS• Blocks generation of pain impulses in peripheral tissue• Antipyresis by inhibiting heat regulating center in hypothalamus• Used: discomfort associated with bacterial & viral infection, headache,

musculoskeletal pain• Client who can’t take ASA products, anticoagulants, or possible bleeding

problems from Gastric or Duodenal Gastritis & Hiatus Hernia• Not effective in RA• Outcome: Reduced pain & fever• CAE: gastric irritation• SAE: liver toxicity