PAIN

• Pain


  An unpleasant sensory and emotional experience, primarily associated with tissue damage or described in terms of such damage
• Pain is the fifth vital sign
• McCaffery and Pasero (1999): 'Pain is whatever the person says it is'
• Gate Control Model


  • Emphasizes the importance of the central nervous system mechanisms of pain
• Nociceptors


  Peripheral nerve endings stimulated by the source of pain which transmit sensations to the central nervous system
• Types of stimuli


  • Mechanical
  • Thermal
  • Chemical - including chemical reactions in tissues causing ischemia or spasm
• Locations of nociceptors


  • Skin, subcutaneous tissue, skeletal muscle joints, peritoneal surface, pleural membranes, dura mater membrane covering the brain, and blood vessel walls
• Physiologic process in nociception

  1. Transduction

  2. Transmission

  3. Modulation

  4. Perception
• Transduction


  Begins when a mechanical, thermal, or chemical stimulus results in tissue injury or damage stimulating the nociceptors
• Transmission


  Initiated by the inflammatory process, resulting in the conduction of an impulse in the primary afferent neurons to the dorsal horn of the spinal cord
• Modulation


  Inhibits pain message and involves the body’s own endogenous neurotransmitters in processing the pain stimuli
• Perception


  Emotional status affects the level of pain perceived and reported by patients, involving the hypothalamus, limbic system, and frontal cortex
• Physiological reactions to pain

  1. Sympathetic stimulation

  2. Parasympathetic stimulation
• Physiologic responses to pain

  Triggering the sympathetic nervous system resulting in physiological responses such as anxiety, fear, hopelessness, sleeplessness, thoughts of suicide, and more
• Classification of pain


  • Duration, Location, Etiology, Severity
  • Acute pain
  • Chronic nonmalignant pain
  • Cancer pain
• Classification of pain location

  • Cutaneous pain
  • Visceral pain
  • Deep somatic pain
• Other types of pain

  • Phantom Pain
  • Neuropathic pain
  • Intractable pain
• Pain


  It is radiating or perceived both at the source and extending to other tissues or referred pain
• Other types of pain

  • Phantom Pain
  • Neuropathic pain
  • Intractable pain
• Phantom Pain can be perceived in nerves left by a missing amputated or paralyzed body part
• Other types of pain not easily classified in the categories mentioned are neuropathic pain and intractable pain
• Neuropathic pain causes an abnormal processing of pain messages and results from past damage to peripheral or central nerves due to sustained neurochemical levels. Exact mechanisms for the perception of neuropathic pain are still unclear
• Intractable pain is defined by its high resistance to pain relief so in this case many patients may have opioid addiction
• 7 Dimensions of Pain

  • Physical
  • Sensory
  • Behavioral
  • Sociocultural
  • Cognitive
  • Affective
  • Spiritual
• Physical dimension includes the patient's perception of the pain and the body's reaction to the stimulus
• Sensory dimension concerns the quality of the pain and how severe the pain is perceived to be. It includes the patient's perception of the pain's location, intensity, and quality
• Behavioral dimension involves verbal and nonverbal behaviors associated with pain
• Sociocultural dimension refers to the effect of social and cultural backgrounds on the experience of pain
• Cognitive dimension includes thoughts, beliefs, attitudes, intentions, and motivations related to the experience of pain (management)
• Affective dimension involves feelings and emotions that result from pain. The pain can affect the emotions and the emotions can affect the perception of pain
• Spiritual dimension relates to the ultimate meaning and purpose attributed to pain, self, others, and the divine
• Pain Assessment


  • Developmental Level
  • Pain in Persons Unable to Provide a Self-Report
  • QUESTT Principles for Pain in Children
  • Cancer Pain
  • Cultural Expressions of Pain
• Pain assessment strategies usually use quantitative and qualitative information because pain has both sensory and emotional components
• Fetuses at least by 26 weeks gestation are known to perceive pain and may feel pain as early as 20 weeks
• Studies have shown that 33 million people aged 65 or older, 62% of nursing home residents, and 25 to 50% of elders living in the community experience significant pain
• Under-treated pain in children can lead to chronic pain conditions when they become adults
• Self-report is always preferred for pain assessment, but if unable, other methods like observing patient behaviors, surrogate reporting, and analgesic trials can be used
• QUESTT Principles for Pain in Children: Question the child, Use pain rating scales, Evaluate behavior and physiological changes, Secure parents’ involvement, Take cause of pain into account, Take action and evaluate results
• Cancer pain may be caused by the cancer itself, its treatment, or its metastasis. It can be acute or chronic and may involve somatic, visceral, or neuropathic pain
• About 90% of patients with advanced cancer experience severe pain, which is often undertreated