Lecture Notes for Mar 7, 2010

Pain Lecture Intro- The experience of Pain ? Complex phenomenon ? Inique to each person ? "Pain is whatever the patient says it is and exists whenever the patient says it does" ? Influenced by the following systems: ? Sensory/discriminative system ? Motivational/affective ? Cognitive/evaluative system ? Pain Categories ? Phsyiologic ? Temporal ? Regional ? Etiological ? Pain can be classified in more than one category Neurophysiology of Pain ? Increases perception ? Prostaglandins ? Lymphokines ? Substane P ? Norpinephrine ? Sympathomimetics ? Serotonin ? Calcitonin-gene-related peptide ? Decrease perception ? Endorphins ? B-Lipotrophin ? Enkephalin ? Dynorphin ? Endomorphins Acute Vs. Chronic Pain ? Acute Physiologic Response ? Increased BP initially ? Increased Pulse ? Increased Resp ? Dilated pupils ? Perspiration ? Acute Behavioral Response ? Restlessness ? Inability to concentrate ? Apprehension ? Distress ? Chronic Physiologic Response ? Normal BP, pulse, and resp rate ? Normal pupils ? Dry skin ? Chronic Behavioral Response ? Immobility or physical inactivity ? Withdrawal ? Despair ? Depression Pain Management ? NSAIDS ? Opiod agonists ? Strong opiod agonist: morphine ? Moderate to Stronge Opiod agonist: codeine ? Agonist-antagonist Opiods ? Patient Controlled analgesia- PCA pumps Action of Opiods ? Bind strongly to mu receptors ? Bind weakly to kappa receptors ? Mimic effect of endorphins to produce analgesia, euphoria, sedation ? Adverse effects: ? respiratory depression, hypotension related to vasodilation, cognitive impairment, urinary retention, increased ICP. ? Dosing Guidelines ? Dosing depends on route of administration ? Half life depends on drug formulation ? Tolerance occurs with prolonged use ? Physical dependence may also occur ? Nursing Considerations ? Accurate pain assessment to guide dosing and monitor efficacy ? Monitor for adverse effects ? Consider potential for drug interactions ? Patient education Nonpharmacologic Pain Management ? Guided relacation ? touch, massage, heat, cold ? Distraction and diversion ? Emotional/psychological support ? Body position ? Environmental management ? Transcutaneous electrical nerve stimulation ? TENS Mechanisms of Arousal ? One hemispheric cortex ? Reticular activating system ? Thalamus ? Common causes of altered arousal ? Impaired cerebral perfusion ? Stroke ? Increased ICP ? CPP= MAP-ICP ? Structural disorders ? Trauma ? Space occupying masses ? Degenerative disorders ? Metabolic imbalanced ? Decreased oxygenation/CO2 narcosis ? Infection ? Fluid and Electrolyte imbalances, impaired glucose metabolism ? Drugs and toxins Manifestations of altered arousal ? Altered level of conciousness ? Agitation/confusion ? Disorientation ? Lethargy ? Obtundation ? Stupod ? coma (ranges from light to deep) ? Persistent Vegetative state (PVS) ? Vomiting ? Pupillary changes ? Oculomotor Changes ? Motor Responses ? Posturing ? Seizure Activity ? Partial seizures- begins with local focus ? simple- no impairmentof consciousness ? complex- impaired consciousness ? Generalized seizures- bilaterally symmetric ? tonic, clonic, or tonic-clonic ? Absence ? simple- loss of consciousness ? complex- with motor involvement ? Specialized epileptic syndromes ? Status epilepticus Common Causes of Seizure ? Causes differ by age but can overlap ? Causes that occur at all ages: ? CNS infection ? Trauma ? Drug or alcohol withdrawal ? Idiopathic ? Hypoxia/ischemia ? metabolic disturbances Antiepileptic Drugs (AED) ? Drug selection is influenced by seizure type ? Most commonly used ? Carbamazepine ? Oxcarbazepine ? Phenytoin ? Valporic Acid ? Mechanisms of Action ? Inhibition of neuronal state via: ? Supression of sodium influx ? Supression of calcium influx ? GABA potentiation ? Nursing considerations ? Monitoring efficacy and adverse effects ? Promoting compliance ? Safe withdrawal from AEDs ? Drug interactions Understanding cognition: Models of hemispheric dominance ? Common model focuses on manual and language dominance ? Functional dominance- each hemisphere is dominant for particular function ? Frontal ? Executive ? Temperal ? Auditory ? Occipital ? Visual ? Attention: the doorway to memory ? Models of attention ? Positive vs. Negative memories ? Attention spotlight Age-Related Cognitive Changes ? Healthy Aging: ? Slowed information processing ? Reduced mental flexibility ? slow learning ? intact test performance ? Age associated memory impairment ? Memory performance worse than young controls ? Aging Associated Cognitive Decline ? Cognition > SD worse than age-matched controls ? Milk Cognitive Impairment ? Memory complaints ? Verbal memory test performance 1.5 SD below mean ? High risk for AD conversion AAN Guidelines: Diagnosis of Dementia ? DSM-IIIR criteria for dementia should be used ? DSM-III-R criteria ? Impaired memory ? One or more of the following: ? Impaired abstract thought ? Impaired judgement ? Disturbed focal cortical function ? (e.g. aphasia, apraxia, agnosia) ? Personality change ? Interferes with daily function ? No acute cause (e.g. labs negative) ? DSM-IV criteria for AD (or NINCDS-ADRDA) should be used ? Memory Impairment ? One or more of ? Aphasia (language disturbance) ? Apraxia (impairment in skilled familiar objects) ? Agnosia (failure to recognize familiar objects) ? Disturbances in executive functioning (planning, organizing, abstract thought) ? Insidious onset and continued decline ? Decline from previously higher level of function ? Negative laboratory evaluation ? Structural imaging is appropriate ? No genetic markers are reliable enough for routine use ? Screening for depression, Vitamin B12 deficiency and hypothyroidism should be performed routinely Differential Diagnosis ? Alzeimer's Disease ? Vascular Dementia (VaD) ? Parkinsonian ? Dementia with Lewy Bodies ? Creutfeld-Jakob disease ? Structural lesion other than stroke Diagnostic Testing ? Detailed history ? Mental Status Examination ? Three word memory ? Clock drawing ? Neuro Imaging ? Blood chemistries ? Chem-20;CBC ? Thyroid function testing ? Vitamin B12 Pharmacologic Management ? Cholinesterase inhibitors (ChEl) ? Donepezil (aricept)- about 2/3 of Rx's ? Galantamine ? Rivastigmine ? NMDA receptor modulator ? Memantine (namenda) Mechanisms of AchI action ? Inhibits enzyme that is responsible for breaking down acetylcholine ? Increases availability of acetycholine in the synapse ? Nursing Considerations ? Adverse effects are cholinergic: muscle cramping, N/V (most common) ? Anticholinergic medications are contraindicated such as bladder antispasmodics (ditropan) ? Therapeutic goal is to delay disease progression, difficult to tell if patient has achieved maximum benefit ? Time to mortality is not changed ? Mechanisms of action of NMDA receptor antagonist ? Glutamate recycling by glial cells is impaired by beta amyloid produced in Alzheimer's disease ? Excess glutamate develops in synaptic cleft and masks signal transmission ? NMDA receptor antagonist blocks effects of excess glutamate and improves signal transmission ? Adverse effects of memantine ? Fatigue ? Pain (HA, back pain) ? Elevated BP ? Dizziness ? Somnolence ? Confusion, hallucination ? GI disturbances (vomiting, constipation) ? Coughing, difficulty breathing ? Nonpharmacologic Management ? Interdisciplinary Management ? Caregiver support ? Patient/Caregiver quality of life ? Conservation of family resources ? Patient protection ? End of life decision making ? Management of behavioral problems Delirium Key DSM-IV Features ? Disorganized cognition ? Two or more of: ? Reduced consciousness ? Perceptual disturbances (e.g. hallucination) ? Altered sleep-wake cycle ? Psychomotor agitation OR retardation ? Disorientation ? Memory impairment ? Evolves over hours to days ? Fluctuating arousal and cognition Overlap with Dementia