Exam 2 Castillo Flashcards
Define Sedative
A drug that induces a state of calm or sleep
Define Hypnotic
A drug that induces hypnosis or sleep
Define Anxiolytic
A drug that reduces anxiety and that has sedation as a side effect
Define Sedative-Hypnotics
A drug that reversibly depresses the activity of the CNS
Define General Anesthesia
State of drug-induced unconsciousness
5 Components of anesthesia
- Hypnosis 2. Analgesia 3. Muscle Relaxation 4. Sympatholysis 5. Amnesia
Besides sedation, what useful dose dependent effect do volatile anesthetics have?
Dose dependent muscle relaxation
What are the 4 stages of General Anesthesia?
- Analgesia 2. Delirium 3. Surgical Anesthesia 4. Medullary Paralysis (Gone too far)
What do you see first in Medullary Paralysis, htn/tachycardia or hypotension/bradycardia?
Hypertension and Tachycardia
Describe Anesthesia Stage 1: Analgesia
Begins with the initiation of an anesthetic agent and ends with the loss of consciousness
What are the airway protective reflexes, and which are lower airway reflexes?
- Sneezing (upper airway) 2. Swallowing (lower airway) 3. Coughing (lower airway) 4. Gagging (lower airway)
What sensory and mental depression signs are associated with stage 1 of anesthesia?
- Able to open eyes on command 2. Breathe normally 3. Maintain protective reflexes 4. Tolerate mild stimuli
Describe Anesthesia Stage 2: Delirium
Starts with the loss of consciousness to the onset of automatic rhythmicity of vital signs
What has caused stage 2 of anesthesia to go more quickly?
Anesthetic agent becoming more rapid and the use of short acting barbituates
What is stage 2 of anesthesia characterized by?
Excitement such as undesired CV instability, dysconjugate ocular movement, laryngospasm and emesis
What is the response to stimuli in stage 2 of anesthesia?
Exaggerated and violent
When would you place an IV in pedi patients?
AFTER stage 2 of anesthesia
Describe Anesthesia Stage 3: Surgical Anesthesia
Absence of response to surgical stimulation
What 5 signs of nervous system depression are associated with stage 3 of anesthesia?
- Hypnosis 2. Analgesia 3. Muscle relaxation 4. Sympatholysis 5. Amnesia
Describe Anesthesia Stage 4: Medullary Paralysis
Associated with cessation of spontaneous respiration and medullary cardiac reflexes
What 4 characteristics are associated with stage 4 of anesthesia?
- All reflexes absent 2. Flaccid paralysis 3. Marked hypotension with weak, irregular pulse 4. May lead to death
When a patient is emerging from anesthesia, how do you determine what signs of distress you should be looking for as time goes by?
The patient will come out of anesthesia the opposite of how the went in, meaning a patient will go from stage 3 to stage 2 to stage 1 during emergence
What is an example of a noninvasive maneuver to treat laryngospasm?
continuous positive pressure ventilation
What was the issue with diethyl ether?
It was slow, unpleasant and a more dangerous tool for induction of general anesthesia
Why are barbiturates not used anymore?
Because they were part of the lethal injection cocktail for capital punishment
When can we use barbiturates in OB patients?
As a last resort if epidural is not working to ease pain
What is the mechanism of action of barbiturates?
Potentiate GABA-a channel activity (directly mimic GABA)
What type of receptors do barbiturates act on?
Glutamate, adenosine, and neuronal nicotinic acetylcholine receptors
What effect if any do barbiturates have on cerebral blood flow?
They cause cerebral vasoconstriction, causing a decrease in CBF and decrease in cerebral metabolic requirement of oxygen by 55%
What is the primary target of barbiturates?
the brain
Why do we see rapid awakening when using barbiturates?
There is a rapid uptake and distribution of the drug to other tissues
What is the onset time of barbiturates?
30 seconds
What is the half-time of barbiturates?
5 minutes
What is the effect of prolonged infusions of barbiturates on its pharmacokinetics?
Lengthy context sensitive half-time
Describe the 4 compartments of drug distribution
- Compartment 1 = Blood 2. Compartment 2 - Vessel rich groups such as the brain, lungs, kidneys, heart, and liver 3. Compartment 3: Vessel poor groups such as the subcutaneous fat and ligaments 4. Compartment 4: Even more vessel poor groups such as the hair, skin and nails
Where are barbiturates metabolized and excreted?
99% hepatocyctes metabolism and excreted in kidneys
What pharmacokinetics do we take into account when giving pediatric patients barbiturates?
Elimination half time is shorter (Pediatric metabolism is very high and requires higher and more frequent dosing)
What do barbiturates bind to in the body?
70-85% bound to albumin
What is the initial site of redistribution for barbiturates?
Skeletal muscles
How fast does barbiturate redistribution to skeletal muscle reach equilibrium with the plasma?
15 minutes
When would redistribution of barbiturates be decreased? Mass decreased?
Decreased: Shock Mass decreased: Elderly
What is dosing of barbiturates based on and why?
Barbiturates dosing is based on lean body weight because larges doses show cumulative effect as fat is a reservoir for the drug
Describe non-ionized drugs
More lipid soluble and favored in acidosis
Describe ionized drugs
Less lipid soluble and favored in alkalosis
4 Previous uses of barbiturates
- Premedication for hangovers (not anymore) 2. Grand mal seizures (benzos have replaced) 3. Rectal admin w/ uncooperative/young patients 4. Increased ICP, cerebral protection and induction
What are the oxybarbiturates?
- Methohexital 2. Phenobarbital 3. Pentobarbital
What are the thiobarbiturates?
- Thiopental 2. Thiamylal
Which isomer, S or R is more potent?
S-isomer
Dose of thiopental (sodium pentothal)?
4mg/kg IV
How long after administering sodium pentothal is only 10% of the drug found in the brain?
30 minutes (will need to re-dose)
What is the dose of thiopental calculated based off of?
ideal body weight
How does methohexital (brevital) compare to pentathol?
- Has a lower lipid solubility 2. At normal pH, 76% is nonionized compared to pentothals 61% 3. Faster metabolism 4. More rapid recovery (still a change of re-sedation)
What is administration of methohexital associated with?
Excitatory phenomena such as myoclonus an hiccoughs
IV dose of methohexital? Rectal dose?
IV dose: 1.5mg/kg Rectal dose: 20-30mg/kg
What adverse effect do we see in patients post methohexital infusion?
1 out of 3 patients will have seizure activity
What effect does methohexital have that is useful for ECT patients?
Duration of seizures are 35-45% less than if etomidate was used
What effect does methohexital have on seizure threshold?
lowers seizure threshold
Cardiovascular effects when given 5mg/kg of thiopental and normovolemia?
- Transient 10 to 20 mmHg decrease in SBP 2. Transient 15 to 20 BPM increase in heart rate
What does the lack of baroreceptor response when using barbiturates cause?
Hypovolemia, CHF, beta blockade
What type of allergic response is seen with a patient who has had previous exposure to thiopental is administered it again?
Anaphylactoid (non-IGE mediated)
What effect if any do barbiturates have on ventilation?
- Dose dependent depression of ventilatory centers 2. Ventilatory centers are less sensitive to CO2
What area do barbiturates effect that are involved in the ventilatory centers?
- Medullary and pontine
What effect do barbiturates have on the return to spontaneous ventilation?
Slow frequency and lower tidal volumes
What is the immediate response if barbiturates are injected intraarterially?
Intense vasoconstriction and excruciating pain that radiates along the distribution of the artery
What is the treatment if intraarterial injection of barbiturates occurs?
- Vasodilators such as lidocaine or Papaverine 2. Sustain adequate blood flow
What is seen with the artery and side effect of intraarterial injection of barbiturates?
- Distal arterial pulses are obscured 2. Blanching of the extremity followed cyanosis 3. Gangrene and permanent nerve damage
What enzyme variability must we be aware of when utilizing barbiturates?
- Enzyme induction is approximately 2 to 7 days of infusion 2. Accelerated metabolism of anticoagulants, phenytoin, TCAs, digoxin, coritocosterioids, bile salts and vitamin K 3. May persist for 30 days
What effect on the kidneys do we see from barbiturates?
Modest, transient decrease in RBF and GFR
What type of monitoring should we utilize when administering barbiturates?
SSEP (somatosensory evoke potential)
What is the fat/blood partition coefficient of thiopental?
11
What is propofol an agonist of?
Relatively selective to GABA-a receptors
Dose of propofol for induction, conscious sedation and maintenance?
Induction: 1.5-2.5mg/kg IV Conscious sedation: 25 to 100 mcg/kg/min Maintenance: 100-300 mcg/kg/min
How quickly does rapid injection of propofol lead to unconsciousness?
30 seconds
What can happen to the soybean oil droplets in propofol solution?
They can coalesce and cause pulmonary embolism
What part of the egg is lecithin found?
The yolk
What are 3 components found in propofol constitutions that we should be aware of?
- Soybean oil 2. Glycerol 3. Purified egg phosphatide (lecithin)
Disadvantages to propofol constitutions?
- Supports bacterial growth, will turn the medication from white to green after 6 hours 2. Causes increased plasma triglyceride concentrations in prolonged infusions (6-24 hours) 3. Pain on injection (do not mix with lidocaine)
How long after drawing up a syringe of propofol is it required of you to discard the entire syringe?
1 hour
2 key points associated with Ampofol as compared to propofol
- Low-lipid emulsion with no preservative 2. Higher incidence of pain on injection
3 key points associated with Aquavan as compared to propofol
- Prodrug that obviates pain on injection 2. By-product causes dysesthia 3. Slower onset, larger Vd and higher potency
What is a strange side effect associated with lidocaine administration?
metallic taste in the mouth
What occurs when GABA-a receptors are activated?
Transmembrane chloride conductance increases causing hyper polarization of the postsynaptic cell membrane and functional inhibition of the postsynaptic neuron
Would you contribute the immobility from propofol anesthesia to spinal cord depression?
No, immobility associated with propofol is not associated with skeletal muscle relaxation
Describe the clearance pharmacokinetics of propofol
- Plasma (lungs) > hepatic 2. Tissue uptake > CYP450
How is propofol metabolized and then excreted?
Hepatic metabolism leads to water-soluble sulfates and glucuronic acid metabolites that are excreted by the kidneys
What is the elimination half time and context sensitive half time of propofol?
- Elimination half-time: 0.5-1.5 hours 2. Context-sensitive half-time: 40 minutes (8 hour infusions)
What is the effect of propofol on systemic blood pressure and heart rate?
Decrease both
What is the effect of etomidate on systemic blood pressure and heart rate?
No change or decreased systemic blood pressure, but no change at all in heart rate
What is the effect of ketamine on systemic blood pressure and heart rate?
Increases both
What effect does cirrhosis of the liver have on propofol?
Similar awakening time with alcoholic and normal patients
What is the effect of renal dysfunction on propofol clearance?
Renal dysfunction has no influence on propofol clearance
What concerns do we have when utilizing propofol on pregnant patients?
Propofol crosses the placenta but is rapidly cleared in neonatal circulation, nonetheless, you will stay have some bradycardia
What do we give prior to propofol administration to counteract the expected bradycardia?
Glycopyralate 3 minutes prior
What type of solution of propofol is used in the ICU to reduce the amount of lipid emulsion administered?
2% solution
What meds are not utilized when doing TIVA?
isoflurane, desflurane, and sevoflurane
Why do children require higher doses of propofol?
They have a larger central distribution volume and clearance rate
What consideration do we give to elderly patients when administering propofol for induction?
Utilize a 25-50% lower dosage
What are the plasma levels of propofol for unconsciousness on induction and awakening?
Unconsciousness on induction: 2 to 6 mcg/mL Awakening: 1 to 1.5 mcg/mL
Why do patients report “such good sleep” after being on propofol?
Propofol induces REM sleep very quickly
5 key points associated with intravenous sedation utilizing propofol?
- Minimal analgesic and amnestic effects 2. Prompt recovery without residual sedation 3. Low incidence of PONV 4. Anti-convulsant and amnestic properties 5. Midazolam and opioids used as adjuncts
What is the agent of choice in brief GI endoscopy procedures?
Propofol
What is the dose of propofol when administering for anti-emetic properties in the PACU? What is the sub-hypnotic infusion dose?
IV push: 10-20mg (1-2mL) Sub-hypnotic infusion: 10-15mcg/kg/min
What is the mechanism of action that allows propofol to be utilized for PONV?
Depression of subcortical pathways and direct depressant effects on the vomiting center
What dose and what procedure can we use propofol for as an anti-pruritic?
10mg IV post neuraxial opioids or cholestasis
Anti-convulsant dose of propofol?
1mg/kg IV
What are the 6 other benefits associated with propofol?
- Anti-pruritic 2. Anti-convulsant 3. Bronchodilator 4. Potent antioxidant 5. Analgesia at low doses 6. Not a trigger for MH
What are the 2 known triggers for malignant hyperthermia?
- Volatile agents 2. Succinylcholine
5 CNS side effects of propofol?
- Decreases CMRO2, CBF and ICP (auto regulation maintained) 2. Large doses may decrease CPP (may need to support MAP) 3. EEG changes similar to Thiopental (suppresses EEG) 4. No SSEP suppression unless volatiles or nitrous added 5. Excitatory movements on induction/emergency (does not product seizure)
What causes the decrease in SBP with propofol administration?
Inhibition of SNS, vascular smooth muscle relaxation and decreased SVR (See a decrease in intracellular calcium)
When do we see an exaggerated response to decreased SBP when administering propofol?
Hypovolemia, elderly patients, Left ventricular compromise
Why do we see bradycardia with propofol administration?
Decreased SNS response and possible depressed baroreceptor reflexes
What response with heart rate in health adult patients can we see with propofol administration?
Profound bradycardia and asystole
What are the effects of propofol on the pulmonary system?
- Dose dependent depression of ventilation to apnea 2. Synergistic with depression w/ opioids 3. Intact hypoxic pulmonary vasoconstriction response 4. Painful surgical stim`. counteracts the ventilatory depressant effects
What effects does propofol have on liver transaminase enzymes or creatine concentrations?
None, they remain normal
What effects does long term infusion of propofol have on the body?
- Hepatocellular injury 2. Propofol infusion syndrome 3. Green urine from phenol excretion (no alteration in renal function) 4. Cloudy urine from uric acid crystallization (no alteration in renal function)
What are the 3 points of propofol infusion syndrome?
- Lactic acidosis 2. Brady-dysrhythmias 3. Rhabdomyolysis
What decreases the amount of pain felt on injection of propofol?
- Lidocaine prior 2. Using larger veins (AC and up)
6 other side effects of propofol not related to pulmonary, cardiovascular or cerebral.
- Pain on injection 2. Decreased IOP 3. Inhibits platelet aggregation 4. Allergic reactions 5. Prolonged myoclonus 6. Abuse and misuse
What dose of propofol can lead to propofol infusion syndrome?
>75 mcg/kg/min for longer than 24 hours
How would we diagnose propofol infusion syndrome?
ABG and serum lactate concentrations
2 Unique characteristics of etomidate?
- Etomidate is the only carboxylated imidazole-containing compound 2. Etomidate is the only drug with direct systemic absorption in oral mucosa that bypasses hepatic metabolism
When is etomidate water soluble? Lipid soluble?
Water soluble: Acidic pH Lipid soluble: Physiologic pH (7.4)
What is the common theme with the 4 medications utilized for induction?
They all cause Myoclonus
What does the 35% propylene glycol mixture with etomidate cause?
Pain on injection
MOA of etomidate?
Selective modulator of GABA-a receptors
Onset of action of etomidate? Elimination half time?
Onset: 1 minute of IV admin Elimination half time: 2-5 hours
What is the metabolism and elimination of etomidate?
Metabolism: Hydrolysis by hepatic microsomal enzymes and plasma esterases Elimination: 85% in urine, 10-13% in bile
What is the Vd of etomidate and what does it tend to bind to in the body?
Vd: large Binds to: 76% bound to albumin
Dose of etomidate?
0.2 to 0.4 mg/kg IV
What is a benefit to using etomidate as an induction medication?
There is no hangover or cumulative drug effect
What patient populations is etomidate best used in?
Unstable cardiac patients who have little or no cardiac reserve (Good for low EF)
Heart induction meds?
1000mcg fentanyl and 10mg versed
Why does myoclonic movement occur?
Alteration in balance of inhibitory and excitatory influences on the thalamocortical tract
How would you attenuate myoclonic activity with administration of etomidate?
Admin opioids such as fentanyl 1-2mcg/kg IV or benzos such as versed prior to administration
What is the occurrence rate of myoclonic activity associated with etomidate administration?
50-80% (higher than thiopental, methohexital and propofol)
Which patient population should we be cautious when giving etomidiate?
Patients with a history of seizure activity, patients who have sepsis or patients who are hemorrhaging
What occurs if we don’t have an adequate stress response?
You will not be able to extubatne the patient after surgery
What effect does etomidate have on the adrenocortical system?
Dose dependent inhibition of the conversion of cholesterol to cortisol
How long does enzyme inhibition last post etomidate administration?
4 to 8 hours
CNS side effects of etomidate?
- Decrease CBF and CMRO2 by 35-45% 2. Similar EEG changes except more frequent excitatory spikes
Why does etomidate decrease CBF and CMRO2?
It is a potent, direct cerebral vasoconstrictor
What considerations should we give to the EEG readings when giving etomidate?
- May activate seiure foci 2. May augment amplitude of SSEP
CV side effects of etomidate? (5)
- CV stable 2. Minimal changes in HR, SV, CO, Contractility 3. Mild decrease in MAP (will have sudden hypotension in hypovolemic patients) 4. No intra-arterial damage 5. Does not release histamine
What induction dose of etomidate predisposes hypovolemic patients to severe, sudden hypotension?
0.45 mg/kg IV
Ventilatory side effects of etomidate?
- Ventilation depressant is less than barbiturates 2. Rapid IV injection leads to apnea 3. Transient (3-5min) tidal volume decrease offset by compensatory increases in frequency of breathing 4. Stimulates CO2 medullary centers
What is ketamine a derivative of?
Phencyclidine (PCP)
What type of anesthesia does ketamine cause?
Dissociative
How will the patient present after administration of ketamine?
Cataleptic state in which the eyes remain open with a slow nystagmic gaze
What does the EEG show after administration of ketamine?
Dissociation between the thalamocortical and limbic systems
What properties does ketamine have as a drug?
Amnestic and analgesic properties
Signs and symptoms of ketamine use?
Noncomunicative, but wakefulness is present; hypertonus and purposeful skeletal muscle movements
What two advantages does ketamine show over propofol and etomidate?
- Lipid emulsion vehicle is not required 2. Profound analgesia at sub anesthetic doses
What psychiatric issue can ketamine assist in treating?
PTSD, bipolar, OCD, pill-resistant depression
2 Disadvantages of ketamine use?
- Frequent emergence delirium 2. Potential for abuse
What preservative is used with ketamine that we have to consider for patient allergies?
Benzethonium Chloride
5 Properties associated with S (+) Ketamine?
- Left-handed optical isomer 2. More intense analgesia than racemic and R (-) 3. More rapid metabolism and recovery 4. Less Salivation 5. Lower incidence of emergence delirium
3 Properties of both S (+) and S (-) Isomer of Ketamine?
- Inhibit uptake of catecholamines back into the postganglionic sympathetic nerve endings (cocaine-like) 2. Less fatigue 3. Less cognitive impairment
What receptor does ketamine bind to?
Noncompetitively to the phencyclidine recognition site on NMDA receptors
What occurs when ketamine binds to NMDA receptors?
Inhibition of activation of NMDA receptors by glutamate and decreased presynaptic release of glutamate
6 other receptors that ketamine binds to
- All opioid 2. Monoamingergic 3. Muscarinic 4. Voltage-sensityive sodium channels 5. L-type calcium channels 6. Nueronal nicotinic acetylcholine (Ketamine has weak actions at GABA-a receptors)
Peak plasma concentration and length of duration of action of ketamine?
Peak plasma: 1 minute after IV and 5 mins IM Duration: Short
What does the large Vd of ketamine do to its elimination half time?
Longer elimination half time of 2 to 3 hours
What solubility does ketamine show?
High lipid solubility (5-10x thiopental)
How is ketamine metabolized and then excreted?
Metabolism: Hepatic, CYP450 Excretion: Kidneys
What is the metabolite of ketamine and what effect does it have on analgesia>
Active metabolites norketamine and it prolongs analgesia
Pharmacokinetic consideration when giving ketamine to burn patients?
Tolerance
Induction (IV and IM), sub anesthetic, post sedation and neuraxial doses of ketamine
Induction: 1-2 mg/kg IV ; 4-8mg/kg IM Subanesthetic (analgesic dose): 0.2-0.5 mg/kg IV Post Sedation and Analgesia: 1-2mg/kg/hr (pedi sx) Neuraxial Analgesia: 30mg epidural or 5-50mg in mL of saline intrathecal
What physical effects do we consider when giving ketamine for induction?
- Induction of salivary secretions d/t muscarinic-R stimulation 2. Maintenance of pharyngeal and laryngeal reflexes predisposes to coughing and laryngospasm
What antisialagogue should we use prior to ketamine admin?
Glycopyrrolate>Atropine/Scopolamine
Timing for loss of consciousness IM/IV, timing of return of consciousness, timing of return to full consciousness with ketamine administration
LOC: 30-60 seconds IV ; 2-4min IM ROC: 10-20 minutes Full consciousness: 60-90 minutes
How long would we expect amnesia post ketamine use persist after return of consciousness?
60-90 minutes
7 clinical uses of ketamine
- Acutely hypovolemic patients 2. Asthmatic and MH patients 3. Coronary artery disease cocktail 4. Pediatric induction (IM route especially) 5. Burn dressing changes, debridements and skin grafting 6. Reversal of opioid tolerance 7. Restless leg syndrome (PO)
Patient populations to avoid ketamine use?
Systemic/pulmonary hypertension and Increased ICP
CNS side effects of ketamine?
- Potent vasodilation 2. Excitatory activity on EEG dose not alter seizure threshold 3. Increased amplitude with SSEP reduced by N2O
Why do we worry about ketamine use in patients with high ICP?
Ketamine increases CBF by 60%
At what dose of ketamine do we no longer see increases in ICP?
0.5 to 2 mg/kg IV
CV side effects of ketamine?
- Resembles SNS stimulation so can give to hypovolemic and sepsis patients 2. Increases SBP, PAP, HR, CO, MRO2 3. Unexpected drops in SBP and CO when catecholamine stores are depleted
Why dose ketamine cause increased SBP, PAP, HR, CO, and cardiovascular MRO2?
It increases plasma epinephrine and norepinephrine levels (Can be blunted by pre-med with benzos or inhaled anesthetics and N2O)
Ventilatory and Airway side effects of ketamine? (6)
- No significant depression of ventilation 2. Ventilatory response to CO2 maintained so will continue to breathe unless given paralytics 3. PaCO2 is unlikely to increase more than 3 mmHG 4. Upper airway skeletal tone and reflex remain intact 5. Bronchodilator activity without histamine release 6. Increased salivary and tracheobronchial mucous gland secretions
Method of action of ketamine that predisposes patients to emergence delirium?
Depression of the inferior colliculus and medial geniculate nucleus
How do we prevent emergence delirium with ketamine use?
Benzos 5 min IV prior to admin of ketamine
Signs and symptoms associated with emergence delirium induced by ketamine
- Visual, auditory, proprioceptive and confusional illusions. 2. Morbid and vivid dreams and hallucinations up to 24 hours
What and why do we expect to see an altered response when administering succinylcholine to a patient who has received ketamine?
What we see: Prolonged apnea Why we see it: Inhibition of plasma cholinesterase’s
What and why do we expect to see an altered response when administering non-depolarizing NMBD’s to a patient who has received ketamine?
What we see: Enhancement of non-depolarizing NMBD’s Why we see it: Inhibition of cytosolic free calcium concentrations
Effects of ketamine on platelets?
Inhibition of platelet aggregation
What is the expected interaction when we administer ketamine with volatile anesthetics?
Hypotension
What are the two components included in the defiintion of pain?
- Sensory-discriminitive
- Motivational-affective
What is the pathway for sensory-discrimintive information?
- Ascending projectiong of spinothalamic and trigeminothalamic tracts
- Cerebral Cortex
- Sensory Processing
- Response
When we feel pain, what information is the cerebral cortex processing?
- Quality of pain: pricking, burning, itching
- Location of the painful stimulus
- Intensity of pain
What are the 4 responses to motivation-affective painful stimuli?
- Attention and arousal
- Somatic and autonomic reflexes
- Endocrine responses
- Emotional Changes
What type of information are most pain signals considered to be?
Afferent
Definition of pain from the international association for the study of pain?
Emphasizes the complex nature of pain as a physical, emotional, and psychological condition
What is the definition of nociception?
The experience of pain with a series of complex neurophysiologic processes
How do medications target causes of pain?
- Actions on transduction
- Transmission
- Interpretation
- Modulation in both PNS and CNS
What is the annual cost of pain?
40 billion
Describe Transduction of pain
Nerve endings: Noxious stimulus to electrical impulses
Describe Transmission of Pain
Conduction of impulses to the dorsal horn of the spinal cord and the thalamus
What are the 3 cortices that recieve pain impulses
- Cingulate
- Insular
- Somatosensory
Describe Modulation of Pain
Process of altering pain transmission; likely both inhibitory and excitatory mechanisms in the PNS and CNS
What is the central relay station for pain that allows us to actually percieve pain?
The thalamus is the central relay station for incoming pain signlas and the primary somatosensory cortex serving for discmination of specific stimulus
5 Locations of Nociceptors
- Skin
- Muscles
- Joints
- Viscera
- Vasculature
Describe afferent pain fibers
Unmyelinated C-fibers and Myelinated A-fibers
What type of pain do C-fibers percieve?
burning pain from heat and pressure from sustained pressure
What type of pain fiber percieves heat, mechanical and chemical stimulus?
Type 1 Myelinated A-fibers (A beta(largest) and A delta)
What type of pain A-fibers percieve heat?
Type 2
What chemical mediators of pain are considered peptides?
- Substance P
- Calcitonin
- CGRP
- Bradykinin (1st released)
What chemical mediators of pain are considered lipids?
- Prostaglandins
- Thromboxanes
- Leukotrines
- Endocannabinoids