Pain Management

LEARNING OBJECTIVES

On completion of the chapter, the learner will be able to:

1. Differentiate between acute pain, chronic pain, and cancer pain. 2. Describe the negative consequences of pain. 3. Describe the pathophysiology of pain. 4. Describe factors that can alter the perception of pain. 5. Demonstrate appropriate use of pain measurement instruments. 6. Explain the physiologic basis of pain relief interventions. 7. Explain the impact of aging on pain. 8. Discuss when opioid tolerance may be a problem. 9. Identify appropriate pain relief interventions for selected groups of

patients. 10. Compare the various types of neurosurgical procedures used to treat

intractable pain. 11. Develop a plan to prevent and treat the adverse effects of opioid

analgesic agents. 12. Use the nursing process as a framework for the care of patients with

pain.

Pain Management Pain (from Ancient Greek ποινή - poine) is defined by

the International Association for the Study of Pain (IASP) as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage”.

Pain is a highly complex and subjective experience that originates from the CNS or peripheral nervous system or both.

Nociceptors- specialized nerve endings that detect painful sensations from the periphery and transmit them to the CNS

Nociceptors are located within the skin, connective tissue, muscle, and the thoracic, abdominal, and pelvic viscera

Nociceptors and Pain Scientists studying the nervous system

have discovered small nerve endings in the skin and other tissues that respond only to strong stimuli, such as a pinch. When these nociceptors are activated, they transmit signals to the brain that can lead to pain. This discovery led to an understanding of how pain occurs and how nociceptors can be altered after injury, resulting in improved methods of pain relief.

NOCICEPTION:

Nociception is the term used to describe how noxious stimuli are typically perceived as pain.

Nociceptors: Peripheral receptors for pain. Nociceptors include receptors which are sensitive to painful mechanical stimuli, extreme heat or cold, and chemical stimuli. All nociceptors are free nerve endings

Can be divided into four phases: TRANSDUCTION TRANSMISSION PERCEPTION MODULATION

TRANSDUCTIONOccurs when a noxious stimuli takes place in the peripheryThese injured tissues then release a variety of chemicalsThese chemicals are neurotransmitters that propagate a pain

message along nerve fibers to the spinal cord TRANSMISSIONTransmission-the pain impulse moves from the level of the spinal

cord to the brainPERCEPTIONPerception-indicates the conscious awareness of a painful

sensationMODULATIONThe pain message is inhibited through the phase of MODULATIONDescending pathways from the brain stem to the spinal cord

produce a third set of neurotransmitters that slow down or impede the pain impulse, producing a analgesic effect

SOURCES OF PAIN:

Pain sources are based upon their origin:

VISCERAL DEEP SOMATIC PAIN CUTANEOUS PAIN REFERRED PAIN

VISCERAL Originates from the larger interior organs (kidney, stomach,

intestine, gallbladder, pancreas) Can stem from direct injury to the organ or from stretching of

the organ Ex: acute appendicitis, ulcer pain

Visceral pain is the pain we feel when our internal organs are damaged or injured and it is, by far, the most common form of pain.

All of us have experienced, at one time or another, pain from our internal organs, from the mild discomfort of indigestion to the agony of a renal colic. Many forms of visceral pain are particularly prevalent in women and are associated with their reproductive life (period pains, labour pain or postmenopausal pelvic pain) and for both men and women, pain of internal origin is the number one reason to consult a doctor.

DEEP SOMATIC PAIN Comes from sources such as the

blood vessels, joints, tendons, muscles, and bone.

Injury may result from pressure, trauma, or ischemia

CUTANEOUS PAIN Derived from skin surface and subcutaneous

tissues. The injury is superficial, with a sharp, burning

sensationREFERRED PAIN Pain that is felt at a particular site but originates

from another location Both sites are innervated by the same spinal nerve May originate from visceral or somatic structures Ex: inflamed appendix RLQ of abdomen may have

referred pain in the periumbilical area

TYPES OF PAIN:

Pain can be classified by its durationACUTE pain -short term and self-limiting, often follows a predictable

track, and ends after an injury heals Ex: surgery, trauma, and kidney stones Acute pain warns the person of actual or potential tissue

damageCHRONIC pain -diagnosed when the pain continues for 6 months or longer.

It can last 5,15, or 20 years and beyond Chronic pain can be divided into malignant and

nonmalignant Malignant-cancer related Nonmalignant- often associated with musculoskeletal

conditions such as arthritis, low back pain, or fibromyalgia Chronic pain does not stop when the injury heals

Effects of painAcute: It can affect pulmonary, cardiovascular, gastrointestinal,

endocrine and immune systems. The stress response: is a neuroendocrine response to

stress occurs with trauma also with other causes of severe pain.

Pain effect is increased in cases of elderly, illness and injury.

Stress response result in increased metabolic rate and cardiac output, impaired insulin response, increased cortisol production and increased fluid retention.

Chronic: The same as acute pain in addition to that: it can result in

depression and disability

Factors influencing pain response:

-Past experience-Anxiety and depression-Culture-Age-Gender-Placebo effect: occurs when a person responds to a

medication or other treatment because of an expectation that the treatment will work more than that actually do. It results from the natural production of endorphins in the descending control system.

Characteristics of Pain

IntensityTimingLocationQualityPersonal meaningAggravating and alleviating factorsPain behaviors

Characteristics of pain

Intensity: It depends on the patient’s pain threshold

(the smallest stimulus for which a person reports pain) and pain tolerance (the maximum amount of pain a person can tolerate).It ranges from none to mild, moderate..,

Timing: some times etiology of pain can be determined when time aspects are known.

Location: Referral pain: pain that radiates.Quality: describe e.g. burning, stapping, squeezing.. ,

Personal meaning: how pain affect the person’s daily life.Aggravating and alleviating factors :

Ascertain whether environmental factors influence pain

Ascertain whether activity influence painPain behaviour: the way person expresses pain (nonverbal and behavioural expression) e.g. grimace, cry, rub the affected area, immobilize it, moan Physiologic response to pain such as: tachycardia, tachypnea, hypertension, pallor, diaphoresis, increased muscle tone, mydriasis,

Nurses role in pain management

- Help in relieving pain by administering relieving interventions.

- Assess the effectiveness of these interventions.

Monitoring for side effects.- Serving as advocate for patient when

prescribed interventions are ineffective.- Serving as educator for patient and family to

enable them to manage the prescribed interventions them selves.

General categories of analgesic agents

1- Local anaesthetic agentsIt works by blocking nerve conduction when applied directly to the nerve

fibres e.g.Topical application,Intraspinal administration 2- Opioids analgesic agents: can be administered through different

routes. side effects: - Respiratory depression and sedation - Nausea and vomiting - Constipation - Inadequate pain relief - Allergies - Tolerance and addiction Tolerance: the need for increasing doses of opioids to achieve the

same therapeutic levelAddiction: is a behavioural pattern of substance use characterized

by a compulsion to take the drug primarily to experience its psychic effect.

General categories of analgesic agents

3- Non Steroidal Anti Inflammatory Drugs (NSAID):

They decrease pain by inhibiting cyclo-oxygenase.

Side effects: stomach irritation, bleeding tendency, and renal impairment.

Second: Non pharmacological interventions

1- Cutaneous stimulation and message: include rubbing the skin

2- Ice and heat therapies 3- Transcutaneous Electrical Nerve Stimulation

(TENS): producing tingling, vibrations, or buzzing sensation in the area of pain.

4- Distraction: involving focusing patient’s attention on some thing other than pain.

5- Relaxation techniques 6- Guided imaginary 7- Hypnosis