Lecture 1.pdf

Lecture 1 Introduction to Pain Management (Historic Overview) Chapters 1,2,3, & 4  OBJECTIVES To recognize the origins of understanding and treating pain. To recognize some eminent leaders in pain treatment and management To recognize the application of...

Lecture 1 Introduction to Pain Management (Historic Overview) Chapters 1,2,3, & 4  OBJECTIVES To recognize the origins of understanding and treating pain. To recognize some eminent leaders in pain treatment and management To recognize the application of systems theory to biopsychosocial patient care Identify the different types of pain and their implications for quality of life Understand the different component of pain understand the subjective experience of pain as a computational neural and mental event  OBJECTIVES Understand the mechanisms of pain information transfer from the periphery to the central nervous system Recognize that the complex systems models of pain include the two-way transfer of information and that socio-cultural factors impact on pain experience Recognize the prevalence of types of chronic pain for population age groups  A Historic View of Pain Ancient Greece emphasize the experience of pain related to war and fighting. Hippocrates was the first ancient Greek physician to change the concept of causes of disease from punishment by the gods to natural causes. Descartes explained sensation, and especially pain, as a way of understanding the union of soul and body. He described how the soul ‘is linked with every part of the body all at once.  A Historic View of Pain He located the soul in the pineal gland because it was a single gland and not replicated.  Anaesthetics and the Transition to Pain-Free Surgery By 1840, some doctors considered pain an evil to be defeated at all costs. Anton Mesmer was an eighteenth-century doctor who introduced into his own clinical practice the hypnotic effect produced in patients known as “mesmerism”. The first anesthesia procedure can be attributed to Crawford Williamson Long in the US (1842). He performed surgery for the first time under general anesthesia by ether. John Snow (1813–1858), the first anesthetist, became a role model for good practice, high standards, and patient safety in surgical anesthesia  The Biopsychosocial Model of Patient Care The holistic care philosophy of nursing has been fundamentally influenced by this system’s approach to patient care, which is known as the biopsychosocial model. From the perspective of patients’ pain experience, it is now agreed that individual A. biological: genetic, gender, and age. B. Psycho: emotional, cognitive, and spiritual. C. Social: cultural, environmental, and ethnic/racial factors all contribute to the subjective experience of pain. There was a need to see patients as people inseparable from their psychological and social context, instead of as just physical bodies separated from minds. This led to major changes in treating and managing pain in advanced cancer and at the end of life, from the patient's perspective  Definitions of Pain The International Association for the Study of Pain (IASP) defines pain as: ‘An unpleasant sensory and emotional experience associated with actual or potential tissue damage. This definition accepts the psychological impact of the pain experience, that pain is always (1) subjective, (2) unpleasant, and (3) influenced by cognitive, affective, and environmental factors.  Types of Pain Two major types of pain: Nociceptive (physiological): is the body's reaction to painful stimuli (stimulation of nociceptors). Neuropathic (pathological): pain initiated or caused by a primary lesion or dysfunction in the nervous system (e.g., phantom pain, painful diabetic polyneuropathy).  Type Nociceptive Pain (Origin) 1. Nociceptive somatic pain: Injury in the skin, subdermal layers, muscle, connective tissues, bones, and joints. A.Superficial somatic pain: activation of cutaneous (body surface) nociceptors and is usually sharp, stabbing, and sometimes burning in quality. B. Deep somatic pain: Activation nociceptors in muscles, bones, joints or connective tissue, and is often described as dull, crampy, and aching. Both superficial and deep somatic pain are usually well localized and often involve local inflammation of injured tissues. 2. Visceral pain: arises from nociceptors in visceral organs such as the gastrointestinal tract or the pelvic region. Visceral acute pain may be vague and poorly defined.  Types of Pain 1. Acute Pain: results when injury activation of primary nociceptive afferents (nerve fibers which respond to pain) leads to acute pain perception, a limited time span, depending on the cause (trauma; some disease processes; invasive interventions). 2. Chronic Pain (non-malignant): is subjective pain experience linked to a previous, not very recent, injury or chronic disease. – The distinction between acute and chronic pain is marked by a time interval, varying between three to six months. – Undertreated and unrelieved severe acute pain is a major predictor of chronic pain. 3. Cancer Pain: highly complex, comprising elements of both acute and chronic pain, both nociceptive and neuropathic in origin.  Pain and Suffering The suffering associated with pain is a personal experience. The person's subjective pain experience must be seen as related to their particular individual, social and cultural context. Listening to the patient's narrative of their pain experience is a particularly important aspect of nursing care. Suffering can be relieved by : A. Source of pain is known B. When the pain can be controlled and will be a relatively short time C. Meaning of Pain.  Phenomenon of Pain Four components are necessary to sufficiently describe the phenomenon of pain. 1. Nociception (activation by noxious stimuli of specialized nerve endings and transmission of pain information to the peripheral and central nervous system). 2. Perception of pain: can be acute or become chronic (if untreated or inadequately treated). 3. Suffering: unpleasant mental state resulting from an event or situation that is perceived to be harmful, uncomfortable, unpleasant, or psychologically or physically painful. – The person in pain frequently reports suffering from pain when they feel out of control, when the source of the pain is unknown, when the meaning of the pain is dire, or when the pain is chronic. 4. Pain behavior: the things that the person says and does or avoids doing due to the presence of pain. Can be influenced by the patient's internal and external environmental contexts and sometimes a result of learning and trying to cope. – Physical changes: like grimacing, limping, poor posture, & reduced mobility and activity – Others: lowered mood, poor sleep.  Pain as a Neural and Mental Experience The pain experience is both neural and mental: 1. the neural component is the activity in nerve cells 2. the subjective experience (emotional , unpleasant) of pain takes place in the mind. Pain is always a psychological state, and the word ‘pain’ can be used to refer to the total experience of both sensation and emotion. The perception of pain is modulated (changed, altered) by the patient's mood, morale, and the meaning of the pain for the patient.  The Neuropsychophysiology of Pain A major function of the central nervous system is to provide information about the occurrence or potential for threat or for injury. This is achieved through neurons and synapses. An afferent neuronal axon carries nerve impulses from a sensory organ to the central nervous system; an efferent neuronal axon carries information from the nervous system to body organs or the periphery. Neurons are classified according to their diameter and conduction velocity (thickness determines speed). Pathophysiology of Pain (The Ascending Pain System) 1. Activation of Nociceptors: action potentials begin polarized from negative to positive potential called depolarization due to pain stimuli. – Tissue injury facilitates increased sensitivity to noxious stimuli and membrane depolarization. 2. Transmission of Pain: information to the dorsal horn of the spinal cord. 3. Ascending of pain signal: through the different neurons of spinothalamic tracts (vary by stimuli types) (Dorsal Horn – Brain Stem – Thalamus – Hypothalamus – Somatosensory Cortex [located in the parietal lobe].  Pathophysiology of Pain (The Descending Pain System) Nociceptive processing by the descending pain pathway can be both: A.inhibitory. B. facilitatory. It is essential to recognize that pain processing is highly dynamic, with information signals traveling up and down the pain pathways, consistent with the concept of a feedback loop. Descending inhibition involves the release of norepinephrine from brainstem nuclei, which inhibits transmitter release from primary afferent pain fibers and limits firing by dorsal horn projection neurons while activation of excitatory serotonin (5HT) appears to enhance spinal processing. The midbrain plays a critical role in pain expression and emotional-related behaviors and has a key role in descending pain modulation. https://youtu.be/5c8maFAhqIc  The Gate Control Theory The theory suggests that the spinal cord contains a neurological “Gate" or Nerve Gate that either blocks pain signals or allows them to continue on to the brain. This gating mechanism takes place in the dorsal horn of the body's spinal cord. 1. Following an injury, pain signals are transmitted to the spinal cord and then up to the brain. 2. the pain messages encounter "nerve gates" that control whether these signals are allowed to pass through to the brain or not. 3. In some cases, the signals are passed along more readily to the brain, and pain is experienced more intensely. In other instances, pain messages are minimized or even prevented from reaching the brain at all.  The Gate Control Theory Tow Types of fiber: A. Small Fibers(Pain Fibers) B. Large Fibers: Normal fibers for touch, pressure, and other skin sensation. Both nerve fibers carry information to two areas of the dorsal horn. These two areas are either the transmission cells that carry information up to the spinal cord to the brain or the inhibitory interneurons which halt or impede the transmission of sensory information.  The Gate Control Theory Large fiber activity excites the inhibitory neurons, which diminishes the transmission of pain information, so people tend to experience less pain. This means that the pain gates are closed. Small Fibers (Pain Fibers) When there is more small fiber activity, it inactivates the inhibitory neurons so that pain signals can be sent to the brain in order for pain perception (also known as nociception) to take place. In other words, the pain gates are now open.  Prevalence of Chronic Pain One in five people in Europe is suffering from chronic pain. A higher prevalence of pain was observed in females compared with males. The most common location for chronic were in the back, joints and neck. Prevalence of Chronic Pain Quality of Pain Management in Jordan Quality of Pain Management in Jordan Quality of Pain Management in Jordan