Pain Kate Black Kate Brazzale Lisa Molony
Pain • Aetiology • Disorder/Disease • Clinical Manifestations • Pathophysiology • Diagnosis • Pharmacological Management • Non-Pharmacological Management • Complications • Implications for Nursing Practice • Pain Case Study
What is pain? According to the International Association for the Society of Pain, Pain is “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage”. (Loeser, 2011)
Aetiology: What causes pain? • “Pain can be due to a wide variety of diseases, disorders and conditions that range from a mild injury to a debilitating disease” (Williams, 2011)
Examples of Pain • Injury (Broken bone) • Disease (Cancer) • Condition (Arthritis) • Illness (Influenza) • Surgery (Caesarean Section)
Acute Pain “The terms acute and chronic refer exclusively to the time course of the pain, irrespective of aetiology”(Craft, Gordon, and Tiziani, 2011, p.144). Acute Pain: • Usually lasts less than 3 months • Sudden onset • Usually know the cause of the pain • Usually well defined • Predicable ending (healing) • Can lead to chronic pain if left untreated • Examples: cut to the finger, broken bone
Chronic Pain Chronic Pain: • Persistent or recurring pain • Continues for more than 3 months • May last for months or even years • Can be difficult to diagnose and treat • Primary goal is not total pain relief but reducing pain relief • Examples include: arthritis and back pain
Categories of pain Another way to categorise pain is on the basis of origin: • Nociceptive • Neuropathic • Psychogenic
Nociceptive Pain Nociceptive pain is directly related to tissue damage and can be either external (somatic) or internal (visceral) External / Somatic • Most common type of pain • Can be superficial -in the skinbut may extend to the underlying tissues. • Usually described as: sharp, shooting, throbbing, burning, stinging • well defined area • Usually lasts from a few seconds to a few days • Examples include: paper cut, sprained ankle
Nociceptive Pain Internal / Visceral (Deep) • Less common and usually more severe • Originates in the walls of visceral organs • Poorly defined area • Described as: deep, aching, pressing or aching • Usually lasts a few days to weeks • Virtually a symptom of all diseases at some point during disease progression. • Often associated with feeling sick • Examples include: Major surgery, labour pain, irritable bowel.
Neuropathic Pain • Injury or disease of the central nervous system rather than the peripheral tissue. • May be due to nerve compression, inflammation or trauma • Usually lasts between a few months to many years. • Difficult to treat due to the lack of knowledge of the underlying cause. • Often associated with paraesthesia, hyperalgesia and allodynia • Burning, shooting or pins and needles (not sharp like nociceptive).
Psychogenic Pain • Psychological, psychiatric or psychosocial are the primary causes • Severe and persistent pain • Appears to have no underlying pathology. • Less common now due to medical technology • Pain experienced (Headaches, abdominal pain, back pain) is indistinguishable from that experienced by people with identifiable injuries or diseases. • This kind of pain can be very frustrating to sufferers and can interfere with their ability to function normally.
Clinical Manifestations Pain Tolerance: The maximum level of pain that a person is able to tolerate without seeking avoidance of the pain or relief What affects Pain Tolerance? • Fatigue, anger, boredom, apprehension, sleep deprivation. Alcohol consumption, medication, hypnosis, warmth, distracting activities and strong beliefs or faiths. “No two people are likely to experience the same level of pain for a given painful stimulus”(Craft et al., 2011, p.150).
Clinical Manifestations Pain tolerance is influenced by a number of factors including; • Age • Cultural perceptions • Expectations • Gender • Physical and mental health
Clinical Manifestations Age: • Different reaction to pain • Understanding of pain Gender: • “Females display greater sensitivity to pain than males do. There are differences in the way women cope with pain, report pain and respond to pain”(Crisp & Taylor, 2009, p.1096). Physical & Mental Health • Physical mobility • Depression, difficulty coping, fatigue.
Cultural Variations Cultures vary in the meaning of pain, how if it expressed and how it is treated: • Meaning • Expression • Treatment
Pain Threshold • Pain Threshold is the lowest point at which pain can be felt • Entirely subjective • May vary from person to person but changes little in the same individual over time.
Location It is important record a patients pain location to be able to monitor any changes. Pain can feel like it is coming from one part of the body but in fact it is another, this type of pain is called referred pain.
Signs and Symptoms: Signs: • Change in temperature • Blood pressure • Respiratory rate • Heart rate • Short of breath • Sweating • Pallor • Dilated pupils • Swelling • Symptoms: • Fatigue • Feeling sick • Weakness • Numbness • Tenderness • Change in behaviour • Unable to sleep
PATHOPHYSIOLOGY • Pain is not a disorder or disease. • A consequential reaction by the body to noxious stimuli. • Injury • Disease • Pain incorporates • Cognition • Emotion • Behaviour • Simple pathway to the brain; • Transduction • Transmission • Perception • Modulation
PATHOPHYSIOLOGY • Transduction • Process by which afferent nerve endings participate in translating noxious mechanical, chemical or thermal impulses into nociceptive impulses. • Strong physical stimuli and disease processes cause chemical release. • Once activated the chemicals bind to specific receptors. • chemicals such as bradykinin, cholecystokinin and prostaglandins, activate or sensitize nearby nociceptors • Lead to the generation of Action Potentials (AP)
PATHOPHYSIOLOGY • Transmission • 1st Order Sensory Neurons • Located in the dorsal root ganglia in the posterior of the spinal cord. • AP’s are conducted to the CNS primarily via two types of primary afferent neurons • A delta Fibres "Epricritic Pain" • C Fibres "Protopathic Pain" • 2nd Order Sensory Neurons • The impulse crosses the spinal cord and ascends to the thalamus and branches to the brainstem nuclei via central transmission. • Messages cross the cord and ascend to the thalamus via the Spinothalamic pathway, heading to the somatosensory cortex, the insula, frontal lobes and limbic system.
A-delta and c fibres • A delta Fibres • "Epricritic Pain" • Mechanical message • Sharp, Fast pain • Thin Myelinated fibres increase speed of processing • C Fibres • "Protopathic Pain" • Mechanical and Thermal Stimuli • Slow, dull, long lasting pain • Unmyelinated fibres, slower response
Peripheral transmission • Peripheral transmission • An electron micrograph showing • large myelinated Aβ • small lightly myelinated Aδ fibres • unmyelinated fibers C Fibres.
Synaptic transmission • Synaptic transmission • Action potential synapse at the dorsal horn of the spinal cord • Neuroactive excitatory and inhibitory neurotransmitters are released • Lead to generation of action potentials and central transmission of pain signals to higher centres.
PATHOPHYSIOLOGY • Perception • When noxious stimuli is recognised. • Multiple areas of the brain • 3rd Order Sensory Neurons • To the higher brain centres of m Limbic system • Frontal cortex, primary sensory cortex of the post central gyrus of parietal lobe • Sensory-Discriminative Response • result of activity in the somatosensory and the insular cortex • allows the person to identify the type, intensity and bodily location of the noxious event. • Affective-Emotional Response • Mediated by the limbic system. • Defines the response and associated behaviour.
PATHOPHYSIOLOGY • Modulation • Dampening or amplifying pain-related neural signals. • Descending input from the brainstem influences central nociceptive transmission in the spinal cord. • Descending inhibition of nociception through the release of neurotransmitters such as serotonin, norepinephrine and endogenous opioids. • Gate Control Theory (Melzack and Wall, 1965) • The body can reduce or increase the degree of perceived pain through modulation of incoming impulses at a gate located in the dorsal horn of the spinal cord. • The integration determines whether the gate will be opened or closed, either increasing or decreasing the intensity of the ascending pain signal. • Psychological variables in the perception of pain, including motivation to escape pain, and the role of thoughts, emotions, and stress reactions in increasing or decreasing painful sensations.
Diagnosis • Diagnosis of Pain is complicated. • To diagnose pain, Nurses rely on • Objective Data. • Visual signs. • Subjective Data. • Patients descriptions. • Characteristics of Pain.
diagnosis • Characteristics of Pain • OPQRST Mnemonic • Onset • Provocation • Quality • Region/Radiation • Severity • Time
diagnosis • Onset • What was the patient doing at the time? • What precipitated the pain? • Is there any history of this pain in the patient? • Provocation • Aggravating Factors: • What causes the Pain to increase? • Alleviating Factors: • What makes it better or worse?
diagnosis 3.Quality • Get the patient to describe their pain to you in specific terms. • What does it feel like? 4. Region/Radiation • Where is the pain? • Where does the pain radiate? • Is it in one place? • Does it go anywhere else? • Did it start elsewhere and now localised to a different spot?
diagnosis 5. Severity • Pain Rating • On a scale of 1 to 10, 10 being the worst pain you have experienced, what number would you assign to your discomfort? • Does their pain change with medication? • Wong-Baker Faces Pain Rating Scale. • Used for • Children • People whose first language is not English.
diagnosis 6. Time • When did the pain start? • How long has the patient has this pain? • Are there any Associated Phenomena? • Factors consistent with pain e.g. Anxiety • Physiological responses • Sympathetic stimulation • Parasympathetic stimulation • Vital signs, skin colour, perspiration, pupil size, nausea, muscle tension, anxiety • Behavioural Responses • Posture, gross motor activities
Dermatomes • 3 Categories • Dermatomes • Connective Tissue and Dermis • Myotome • Skeletal Muscle • Sclerotome • Vertebrae • Dermatomes in relation to pain • An area of skin in which sensory nerves derive from a single spinal nerve root.
Dermatomes • Spinal Cord Dermatomatic Relationships • Trigeminal Nerves • V1Ophthalmic Division – Eye • V2 Maxillary Division – Top of Jaw • V3 Mandibular Division – Bottom of Jaw • Cervical (C-2 - C-7) • fingers, neck, funny bone, and the scalp. • Thoracic (T-1 - T-12) • nipples, chest, belly button area, pubic bone, and lower sternum. • Lumbar (L-1 - L-5) • hips, the front of the legs, the shins, knee caps, and most of the feet. • Sacral (S-1 - S-5) • genitals, buttocks, back of the legs, and calves
Diagnostic Tests Tests to verify pain. • Ultrasound Imaging • High frequency sound waves to develop an image of the affected area. • CT/CAT scan • Computed Tomography or Computed Axial Tomography • X-rays to produce an image of a cross-section of the body. • MRI Scan • Large magnet, radio waves and a computer produces detailed images of the body.
Diagnostic - Tests • Discography/Myelograms • A contrast dye is injected into the spinal disk to enhance the X-Ray. • EMG (Electromyography) • Evaluate the activity of the muscles. • Bone Scans • Diagnose and monitor infection and fracture of the bone
Diagnosis • Psychological Assessment • Pain Questionnaires • Determine Psychological Involvement. • Brain functions governing behaviour and decision making, including expectation, attention and learning. • Fear • Anxiety • Depression • Coping • Psychosocial involvement. • Plays a large role in pain perception. • Age, Sex, Culture, previous experiences.
Pharmacological management • The management of pain through analgesics • Analgesic: a compound that relieves pain by altering perception of nociceptive stimuli without producing anaesthesia or loss of consciousness • Three types of analgesics: • Opioids (narcotic) analgesics • Non-opioid analgesics (NSAIDs) • Adjuvants
Pharmacological management • Routes of administration: • Oral • Continuous infusion (via SC or IV routes) • PCA (patient controlled analgesia) • Epidural • Rectally • Transdermal administration • Inhalation
GENERAL PRINCIPLES of pain management • Treat the cause of pain where possible, not just the symptom • Make accurate diagnosis and assessment of pain extent and type • Keep the patient pain free • Dose at regular specified intervals • Avoid the chronic pain stress cycle • Prevent adverse effects of opioids • Develop a patient management plan • Follow the WHO analgesia ladder
Pharmacological management • WHO has developed a three-step ladder for pain relief • If pain occurs, the use of oral of drugs should be administered in the following order: • non-opioids • mild opioids • strong opioids Image: World Health Organization http://www.who.int/cancer/palliative/painladder/en/
Opioids • Generally prescribed for moderate – severe pain • Act on CNS by binding with opiate receptors to modify perception and reaction to pain • The most commonly used opioid is morphine
Opioids • Adverse drug reactions may include: • respiratory depression • excessive sedation • constipation • nausea • vomiting • tolerance • dependence • dysphoria (a mood of general dissatisfaction, restlessness, anxiety)
nsaids • Non-steroidal anti-inflammatory drugs • Used to treat mild – moderate pain • Work by acting on peripheral nerve receptors to reduce transmission and reception of pain stimuli • Common NSAIDs include: • Paracetamol • Aspirin • Ibuprofen • Naxopren (arthritis)