Week 7: Pain & Anesthetics Flashcards
(147 cards)
1
Q
Immediate goal of pain management
–Reduce pain to level that allows patient to:
A
perform reasonable ADLs
2
Q
Key principles of pain management
–Patient should be considered_______of their pain.
–Pain management is a patient _______.
–Nonpharmacologic interventions _____________.
▪Combination of therapies optimal
A
–Patient should be considered expert of their pain.
–Pain management is a patient right.
–Nonpharmacologic interventions encouraged.
▪Combination of therapies optimal
3
Q
Acute vs Chronic pain
A
▪Acute pain = Abrupt onset but brief duration
▪Chronic pain = persists longer than 6 months
–Chronic nonmalignant pain
–Chronic malignant = Cancer pain
4
Q
Nociceptor vs Neuropathic pain
A
▪Nociceptor = Responds well to analgesics
–Somatic = Localized muscles or joints
–Visceral = Organs
▪Neuropathic = caused by Injury or irritation to nerve tissue
5
Q
Phases of pain physiology
- _____________: trauma stimulates ____________
- Transmission in ___________________
- Transmission in ____________________
- ______________ [cerebral cortex recognizes the pain stimulus]
- ____________: limbic system reacts to pain
A
- Transduction: trauma stimulates nociceptors
- Transmission in peripheral nerves
- Transmission in spinal tracts
- Perception [cerebral cortex recognizes the pain stimulus]
- Modulation: limbic system reacts to pain
6
Q
Nonpharmacologic therapies are used to attain adequate pain relief in place of drugs
– Serve as adjuncts to analgesics
Improved comfort, lower doses, potential for fewer drug related
adverse events
Examples:
A
▪Acupressure and acupuncture
▪Hypnosis, massage, meditation
▪Application of cold or heat
▪Biofeedback therapy & Electrical nerve stimulation
▪Distraction = Art/music therapy/ Laughter
▪Physical therapy
▪Yoga
7
Q
Drug classes for pain meds
A
▪Nonopioids
–NSAIDs, centrally acting agents, or acetaminophen
–Used for mild to moderate pain
▪Opioid drugs
–Used to treat severe pain
▪Adjuvant analgesics
–Used to treat chronic pain that’s neuropathic in nature
8
Q
Combination drugs for pain
–Opioid & nonopioid drugs
–Available as fixed-dose tablets or capsules
–Dose ceiling due to toxicities of nonopioid analgesic
▪Such as risk of acute liver failure when taking acetaminophen
–Common examples: ?
A
–Opioid & nonopioid drugs
–Available as fixed-dose tablets or capsules
–Dose ceiling due to toxicities of nonopioid analgesic
▪Such as risk of acute liver failure when taking acetaminophen
–Common examples: Endocet, Norco, Percocet
9
Q
Management of cancer pain
A
–Radiation therapy
–Nerve blocks
▪Alcohol / other neurotoxic substance
▪Local anesthetics / steroid hormones
10
Q
Patient-controlled analgesia
A
–Infusion pump allows patient to self-administer.
–May reduce anxiety of waiting for drug administration
–Morphine usually used.
–Requires patient be conscious and capable of understanding pump operation
11
Q
Opium (Papaver somniferum)
–Extracted from unripe :
A
poppy plant seeds
12
Q
Opiates
–Natural substances obtained from:
–Include:
A
–Natural substances obtained from opium
–Include morphine and codeine
13
Q
Opioid
–Synthetic drug with _____________ activity
–Can be _________ or __________
A
–Synthetic drug with morphine-like activity
–Can be natural or synthetic
14
Q
Opioids are usually used for:
A
moderate to severe pain
15
Q
Opioids when used for prolonged periods at high doses, can cause :
A
physical and psychological dependence
16
Q
Narcotic: _________________ drug used to alleviate pain
A
Morphine-like
17
Q
3 common receptors that opioids work with:
A
Mu
Kappa
Delta
18
Q
Opioid agonists activate ___________________ receptors
A
mu and kappa
19
Q
Opioid antagonists block _______________ receptors
A
mu and kappa
20
Q
Mixed opioid agonist-antagonists work on one receptor but :
A
block or have no effect on another
21
Q
Opioids
–Neither lower threshold for pain at nociceptor level nor _________________1_____________________
–Alter _______2_________, emotional response
▪Patient knows pain exists, but it does not cause concern or anxiety.
A
1- slow/block transmission of pain impulse
2- perception
22
Q
Opioids Cause CNS depression:
A
Sedation, euphoria, intense relaxation
23
Q
Opioids side effects
A
– GI side effects
▪Nausea, vomiting, constipation
– Urinary retention
– Pruritus
– Respiratory depression
– Orthostatic hypotension
– Increased intracranial pressure (ICP)
– Risk of physical and psychological dependence
– Dizziness, hallucinations, anxiety
– Tolerance
24
Q
Prototype drug: Morphine sulfate (Astramorph PF, Duramorph RF, Roxanol)
–Therapeutic classification-
–Pharmacologic classification-
A
–Therapeutic classification
▪Narcotic analgesic
–Pharmacologic classification
▪Opioid agonist
25
Prototype drug: Morphine sulfate (Astramorph PF, Duramorph RF, Roxanol)
–Therapeutic effects and uses
▪Acute and severe _______________
▪Off label
–Preanesthetic __________ and to calm severely agitated patients
–Relieve _________________________ associated with end-stage cancer, heart failure, or pulmonary edema
▪Acute and severe chronic pain
▪Off label
–Preanesthetic sedation and to calm severely agitated patients
–Relieve shortness of breath associated with end-stage cancer, heart failure, or pulmonary edema
26
Prototype drug: Morphine sulfate (Astramorph PF, Duramorph RF, Roxanol)
–Mechanism of action
▪Occupies mu and kappa receptor sites in brain and dorsal horn of spinal cord that alter release of afferent neurotransmitters
▪Alters perception of and emotional response to pain
▪Produces analgesia and euphoria
▪Mimics actions of endogenous endorphins
27
Prototype drug: Morphine sulfate (Astramorph PF, Duramorph RF, Roxanol)
–Adverse effects
-Black box warning
▪CNS depression
▪Respiratory depression
▪Constipation, nausea, vomiting
▪Urinary retention
▪Sedation, dizziness, anxiety, disorientation
▪Orthostatic hypotension
▪Pruritus with IV or epidural route
–Black box warning
▪Schedule II controlled substance with high
potential for physical and psychologic dependence
▪Extended release forms prescribed for opioid tolerant patients only and are not intended for prn use
28
Prototype drug: Morphine sulfate (Astramorph PF, Duramorph RF, Roxanol)
–Contraindications/precautions
▪Hypersensitivity
▪Premature infants
▪Precautions
–Older adults
–Undiagnosed abdominal pain
–Hepatic/renal impairment
–Shock
–CNS depression
–Head injury/increased ICP
–COPD
29
Morphine sulfate
–Drug interactions
▪Increased sedation
–CNS depressants
▪Reversed effect with opioid antagonist
–Naloxone
▪Additive constipation
–Antidiarrheal
30
Morphine sulfate
–Herbal/food
▪Kava, valerian, or chamomile can increase CNS depression
▪St. John’s wort may decrease analgesic action
31
Morphine sulfate Treatment of overdose
▪Overdose can cause coma & respiratory depression
–Immediate treatment
–Naloxone for morphine intoxication
32
Mixed agonist-antagonist opioids
–Fewer ________ effects
▪Less ___________ depression
▪Lower potential for dependence
–Used to treat ____________ pain
–Fewer adverse effects
▪Less respiratory depression
▪Lower potential for dependence
–Used to treat moderate pain
33
Buprenorphine (Buprenex, Butrans, Suboxone)
–Partial agonist at ____ receptors
–Antagonist at _____ receptors
–Parenteral route
▪Relief of moderate to severe pain
–Sublingual route
▪Management of opioid withdrawal & dependence
–Schedule III drug
–Partial agonist at mu (μ) receptors
–Antagonist at kappa receptors
34
Butorphanol (Stadol)
–Agonist at ? receptors
–Weak antagonist at ? receptors
–IV or IM route
▪Moderate to severe pain
▪Preanesthesia or general anesthesia adjunct
–Nasal spray
–Schedule III drug
–Agonist at kappa receptors
–Weak antagonist at mu receptors
35
Nalbuphine (Nubain)
–Agonist at ? receptors
–Weak antagonist at ? receptors
–IV, IM, subcutaneous routes
▪Moderate to severe pain
▪Preanesthesia or anesthesia adjunct
–Not a scheduled drug
–Agonist at kappa receptors
–Weak antagonist at mu receptors
36
Pentazocine (Talwin)
–Agonist at ? receptors
–Weak antagonist at ? receptors
–PO and parenteral routes
▪Moderate to severe pain
–Agonist at kappa receptors
–Weak antagonist at mu receptors
37
NSAIDs (Aspirin, ibuprofen)
– Preferred medications ^^
– Have antipyretic and anti-inflammatory properties
– Act at ______________, inhibiting pain mediators at _______________ level
– Preferred medications
– Have antipyretic and anti-inflammatory properties
– Act at peripheral sites, inhibiting pain mediators at nociceptor level
38
NSAIDs (Aspirin, ibuprofen) do not produce severe adverse effects of narcotics
▪No physical or psychological dependence
▪Most prominent effects:
–GI related
* Ulceration of mucosa
–Dizziness, headache, and rash
39
Miscellaneous analgesics such as
▪Clonidine (Catapres, Duraclon)
▪Ziconotide (Prialt)
–Tramadol (Ultram, others)
▪More widely prescribed
–Act on : ?
CNS
40
Tramadol (Ultram, others)
–Therapeutic classification
–Pharmacologic classification
–Therapeutic classification
▪Analgesic
–Pharmacologic classification
▪Mixed opioid-nonopioid analgesic
41
Tramadol (Ultram, others)
–Therapeutic effects and uses:
▪___________ pain
▪Off-label uses
–Neuropathic pain
–______________ ________ syndrome
▪Moderate pain
▪Off-label uses
–Neuropathic pain
–Restless leg syndrome
42
Tramadol (Ultram, others)
–Mechanism of action
▪Drug and one of metabolites bind to _______________ site
–Weak opioid agonist activity
▪Inhibits_________________________________________ reuptake in spinal neurons
–Inhibits transmission of pain impulses
▪Drug and one of metabolites bind to mu receptor site
–Weak opioid agonist activity
▪Inhibits norepinephrine and serotonin reuptake in spinal neurons
–Inhibits transmission of pain impulses
43
Tramadol (Ultram, others)
–Adverse effects
▪Vertigo / Dizziness
▪Headache
▪Nausea / Vomiting
▪Constipation
▪Lethargy
▪CNS stimulation effects
▪Seizures
▪Respiratory depression
▪Possible physical dependence
44
Tramadol (Ultram, others)
– Contraindications/precautions
▪Hypersensitivity
▪History of depression or suicidal ideation
▪Pregnancy
▪Precautions
–Codeine allergies
–History of drug abuse
–Chronic Obstructive Pulmonary Disease (COPD)
–Renal/hepatic impairment
–Increased ICP
–History of seizures
–Contraindicated in children younger than age 12
45
Tramadol (Ultram, others)
–Drug interactions
▪Increased risk of seizures
–Carbamazepine, certain antidepressants
–MAOIs
▪Sudden death if combined with ethanol
▪Reduced analgesic effect
–Inhibitors of CYP2D6 enzyme
▪Herbal/food
–Food significantly affects absorption of
extended release form
–St. John’s wort contraindicated; possibility of
serotonin syndrome
–Caution with valerian or kava; additive CNS
depressant effect
46
Tramadol (Ultram, others) –Treatment of overdose
▪Serious CNS depression, respiratory depression, death possible
▪Naloxone
–May precipitate convulsions
47
Adjuvant analgesics
–Diverse group of drugs used to : ?
enhance analgesia for specific indications
48
* Adjuvant analgesics
Primary indications
▪Pain refractory to opioids (such as intractable cancer pain)
▪Neuropathic pain
49
Preferred drugs for abusers:
Morphine, meperidine, and heroin
* OxyContin
–Major drug of abuse in recent years
–Long-acting form of oxycodone
▪Beneficial to patients with chronic pain
▪Can be crushed, injected, snorted
–Potent and dangerous
50
Acute opioid intoxication - Respiratory depression
▪Treat with : ?
▪Repeat small doses until patient exhibits opioid withdrawal symptoms
–Maintain patent ____________
–Have resuscitation equipment available
▪Treat with naloxone (Narcan)
▪Repeat small doses until patient exhibits opioid withdrawal symptoms
–Maintain patent airway
–Have resuscitation equipment available
51
* Evzio
–Handheld autoinjector containing naloxone to treat individual with :
known or suspected opioid overdose
52
–Tension headache
▪Muscles of head & neck tight due to :
▪Treat with :
▪Muscles of head & neck tight due to stress
▪Self-limiting
▪Treat with OTC analgesics
53
Migraine headache
▪Throbbing, pulsating pain
▪Preceded by aura
–Sensory warning of imminent attack
▪Patients appear to have___________________ that overreact to various triggers.
▪Neurotransmitter _______________ plays key factor.
▪Throbbing, pulsating pain
▪Preceded by aura
–Sensory warning of imminent attack
▪Patients appear to have blood vessels that overreact to various triggers.
▪Neurotransmitter serotonin plays key factor.
54
About ____ of patients with migraines have a first degree relative with a history of migraine.
70%
55
Before puberty, more boys have migraines than girls;
after puberty, women are _______ more likely to have migraines than men.
3 times
56
History of migraine is associated with an increased incidence of __________________________________, especially if the patient experiences migraines with aura.
major cardiovascular disease
57
* Migraines are rare after age:
50
58
Mild migraine (occasional headaches with no other functional impairment) treatment
–NSAIDs
–Acetaminophen combined with NSAID and caffeine
–Oral serotonin 5-HT agonists
▪Triptans/ergot alkaloids
59
Moderate migraines (moderate headaches, nausea, some functional impairment) treatment
–Oral, intranasal, subcutaneous serotonin (5-HT) agonists
▪If contraindicated or ineffective, then dopamine agonists prescribed
60
Severe migraine (severe headaches more than 3 times/month, marked nausea or vomiting, functional impairment) treatment
–Subcutaneous, IM or IV serotonin agonists
–Second-choice parenteral dopamine agonist
–Narcotic analgesics for refractory pain
61
Triptans
–Selective for 5-HT1 receptor subtype
–Constrict certain intracranial vessels
–Effective in aborting migraines with or without auras
–Not effective at __________ migraines
preventing
62
Ergot alkaloids
–For patients unresponsive to triptans
▪Separate use by 24 hours
–Constrict ________________________
–Regular daily use can cause physical dependence.
both arteries and veins
63
Sumatriptan (Imitrex, Onzetra)
–Therapeutic classification
–Pharmacologic classification
–Therapeutic classification
▪Antimigraine agent
–Pharmacologic classification
▪Serotonin (5-HT1) receptor agonist
64
Sumatriptan (Imitrex, Onzetra)
Therapeutic effects and uses:
▪Acute migraine headaches
65
Sumatriptan (Imitrex, Onzetra)
–Mechanism of action
▪Activates : 5-HT1 _______________________________ on intracranial and extracerebral blood vessels
–Cranial vessel constriction
–Reduced transmission in trigeminal pain pathways
▪Activates 5-HT1 serotonin receptors on intracranial and extracerebral blood vessels
–Cranial vessel constriction
–Reduced transmission in trigeminal pain pathways
66
Sumatriptan (Imitrex, Onzetra)
–Adverse effects
▪Mild, transient dizziness
▪Nausea
▪Diarrhea
▪Myalgia
▪Inflammation or pain at injection site
▪Headache recurrence
▪Serious adverse cardiac effects
67
Sumatriptan (Imitrex, Onzetra)
–Contraindications/precautions
▪Epilepsy
▪CAD
▪Cerebrovascular disease
▪Peripheral vascular disease
▪Uncontrolled hypertension, hypercholesterolemia
▪Family history of cardiovascular disease
▪Renal/hepatic impairment
▪Pregnancy
68
Sumatriptan (Imitrex, Onzetra)
–Drug interactions
▪MAOIs, SSRIs- should not be used within 2 weeks of such drugs
▪Avoid use within 24 hours of ergot alkaloids or other 5-HT1 agonist
▪Serotonin syndrome possible
▪Drugs that increase serotonin levels or activity
–Herbal/food
▪St. John’s wort and feverfew avoided
69
–Treatment of overdose
Sumatriptan (Imitrex, Onzetra)
▪Few recorded
▪Supportive of side effects
70
Preventive treatment is recommended for headaches that occur 3 or more times a month.
– Identify personal triggers for migraines:
▪Foods/diet
▪Adopting regular sleep patterns and meals
▪Aerobic exercise
▪Avoiding alcohol (especially red wine)
▪Smoking cessation
▪Keeping a diary
▪Relaxation exercises
▪Meditation
▪Yoga
▪Progressive muscle relaxation
71
Preventive treatment is recommended for headaches that occur 3 or more times a month.
–Pharmacologic treatment:
▪________________ blockers
▪_______________blockers
▪Anti____________
▪Anti____________
▪Beta-adrenergic blockers
▪Calcium channel blockers
▪Antidepressants
▪Antiseizure drugs
72
General anesthesia
–Loss of ___________ throughout whole body
–Accompanied by loss of:
–Loss of sensation throughout whole body
–Accompanied by loss of consciousness (LOC)
73
Local anesthesia
–Loss of __________ to limited body area without LOC
sensation
74
Regional anesthesia
–Similar to local
–Encompasses :
larger body area, such as entire limb
75
–Minimal sedation (anxiolysis)
▪Patient responds to
responds to verbal commands.
76
Moderate (conscious) sedation
▪Patient responds to: ?
verbal or light tactile prompting
77
–Deep sedation/analgesia
▪Patient aroused by : ?
▪Airway, ventilation interventions
▪Cardiovascular functions usually adequate
▪Patient aroused by repeated or painful stimulation
▪Airway, ventilation interventions
▪Cardiovascular functions usually adequate
78
General Anesthesia
* Purposes
–Analgesia [blocks pain sensation]
–Relaxation [relieves anxiety]
–Hypnosis
–Amnesia
–Loss of reflexes
79
Balanced anesthesia
–Combination of medications:
▪___________ blockers
▪Short-acting ___________
▪Opioids
▪General ___________
▪Neuromuscular blockers
▪Short-acting benzodiazepines
▪Opioids
▪General anesthetics
80
4 stages of general anesthesia
* Stage I
–________ = lose sensation, but may remain awake
* Stage II
–______________ and ________________
▪May have irregular pulse and respirations with
increased blood pressure
* Stage III
–Surgical ______________ = Skeletal muscle relaxation
* Stage IV [avoided]
–Paralysis of _____________ = Death could result
* Stage I
–Analgesia = lose sensation, but may remain awake
* Stage II
–Excitement and hyperactivity
▪May have irregular pulse and respirations with
increased blood pressure
* Stage III
–Surgical anesthesia = Skeletal muscle relaxation
* Stage IV [avoided]
–Paralysis of medulla = Death could result
81
Intravenous Anesthetics
* Commonly used classes :
–Opioids
–Benzodiazepines
–Miscellaneous agents
82
* Neurolept analgesia
–Feelings of ______________ to patient's surroundings
indifference
83
Fentanyl (Sublimaze)
–Therapeutic classification
–Pharmacologic classification
–Therapeutic classification
▪Analgesic
▪Anesthetic
–Pharmacologic classification
▪Opioid agonist
84
Fentanyl (Sublimaze)
–Therapeutic effects and uses
▪Short-duration analgesia
▪Chronic, persistent pain
85
Mechanism of action of Fentanyl (Sublimaze)
▪________________ against mu and kappa receptors
▪More _________onset of action than morphine
▪Opioid agonist against mu and kappa receptors
▪More rapid onset of action than morphine
86
Fentanyl (Sublimaze)
–Adverse effects
▪Most common = Respiratory depression (5-15 min
after IV), apnea, skeletal muscle rigidity,
bradycardia, nausea, vomiting, constipation
▪Transdermal patches
–Localized pain
–Irritation
–Ulceration
–Bleeding
87
Fentanyl (Sublimaze)
–Black box warning
▪High risk for misuse, abuse, or diversion
▪High risk for death due to overdose or respiratory
depression
▪Concurrent use with CYP450 3A4 inhibitors
–Increase fentanyl plasma concentrations
▪Concurrent use with CNS depressants
–Profound sedation, respiratory depression,
coma, and death
88
Fentanyl (Sublimaze)
–Contraindications/precautions
▪Head trauma
▪Lactation
▪Respiratory impairment
▪Bradydysrhythmia
▪Hepatic or chronic kidney disease
89
Fentanyl (Sublimaze)
–Drug interactions
▪Additive CNS depression
–Other CNS depressants
▪Interacts with drugs that induce/inhibit CYP450
enzyme
▪Cardiovascular depression
–Nitrous oxide
–Herbal/food
▪St. John’s wort may intensify or prolong effects.
▪Valerian or kava may cause additive CNS
depression.
90
–Treatment of overdose for Fentanyl (Sublimaze)
▪Mechanical ventilation
▪Naloxone (Narcan) to reverse serious respiratory
depression
91
Primary indication for benzodiazepine use is to treat symptoms of :
anxiety
92
__________ most commonly used for surgical procedures
Midazolam
93
______________ & ___________ have slower onset, longer duration.
–Used as anesthesia adjuncts
Diazepam and lorazepam
94
Midazolam (Versed)
–Therapeutic classification
–Pharmacologic classification
–Therapeutic classification
▪IV anesthetic
–Pharmacologic classification
▪Benzodiazepine
▪GABA receptor agonist
95
Midazolam (Versed)
Therapeutic effects and uses
▪Reduces anxiety and stress during surgery
▪Off-label use = Status epilepticus
▪Off-label use = Mechanically ventilated patients
96
Midazolam (Versed)
–Mechanism of action
▪Produces CNS depression and skeletal muscle relaxation
▪Acts at limbic, thalamic, hypothalamic regions of brain
97
Midazolam (Versed) –Adverse effects & black box warning
▪Drowsiness
▪Fatigue
▪Ataxia
▪Slurred speech
▪Tremor
–Serious adverse effects
▪Hypotension
▪Tachycardia
▪Cardiovascular collapse
▪Laryngospasm
–Black box warning
▪Respiratory depression and arrest
98
Midazolam (Versed)
–Contraindications/precautions
▪Acute, closed-angle glaucoma
▪Acute alcohol intoxication
▪Shock
▪Coma
▪Depressed vital signs
99
Midazolam (Versed)
–Drug interactions
▪Additive CNS depression
–Other CNS depressants
▪Increased serum phenytoin levels/additive CNS
depression
–Dilantin
▪Interactions with drugs that inhibit or induce
CYP3A4 enzyme
100
Midazolam (Versed)
–Herbal/food interactions
▪Increased sedation with kava or valerian
▪Grapefruit juice may increase serum concentration
▪Melatonin may increase sedation
101
–Treatment of overdose for Midazolam (Versed)
▪General supportive measures
▪Flumenazil (romazicon) - Benzodiazepine antagonist –May induce seizures with rapid reversal
102
Propofol (Diprivan)
– Therapeutic classification
– Pharmacologic classification
– Therapeutic classification
▪IV anesthetic
▪Sedative–hypnotic drug
– Pharmacologic classification
▪N-methyl-D-aspartate (NMDA) receptor agonist
103
Propofol (Diprivan)
– Therapeutic effects and uses
▪IV anesthetic
▪Off-label
–Refractory migraines
–Refractory status epilepticus
–Treatment of agitation associated with alcohol withdrawal
104
Propofol (Diprivan)
–Mechanism of action
▪Exact mechanism not clear
▪Believed to activate GABA receptors, causing
general inhibition of CNS activity
105
Propofol (Diprivan)
Adverse effects
▪Injection site pain
▪Apnea
▪Respiratory depression
▪Hypotension
–Serious adverse effects
▪Metabolic abnormalities
▪Propofol infusion syndrome (PRIS)
106
Propofol (Diprivan)
–Contraindications/precautions
▪Hypersensitivity to soybean and egg products
▪Obstetric patients
▪Intracranial pressure
▪Cardiac or respiratory impairment
107
Propofol (Diprivan)
–Drug interactions
▪Reduced dose in patients receiving preanesthetic
medications
▪Other CNS depressants can cause additive CNS
and respiratory depression
108
Propofol (Diprivan) –Treatment of overdose
▪Mechanical ventilation
▪Increasing flow rate of IV fluids
▪Vasopressor agents
109
_______ are given following administration of IV agents
Gases
110
Today, _______________ is the only gaseous anesthetic in use.
nitrous oxide
111
gaseous anesthetic in use.
Rapidly absorbed into general circulation
–Very _________ soluble
–Cross _________________ barrier
Rapidly absorbed into general circulation
–Very lipid soluble
–Cross blood–brain barrier
112
Nitrous oxide
–Therapeutic classification
–Pharmacologic classification
–Therapeutic classification
▪Gaseous general anesthetic
–Pharmacologic classification
▪GABA-receptor agonist
▪Opioid agonist
113
Nitrous oxide
Therapeutic effects and uses
▪Minor medical and surgical procedures
114
Nitrous oxide
–Mechanism of action
▪Not fully known
▪Believed to be due to activation of opioid receptors in midbrain
▪Relaxation properties likely due to activation of GABA receptors
115
Nitrous oxide
Adverse effects (at high doses)
▪Anxiety
▪Excitement
▪Combativeness
▪Alveolar hypoxia
116
Nitrous oxide
–Contraindications/precautions
▪Inability to comply with instructions and/or Impaired LOC
▪Undiagnosed abdominal pain, abdominal distention, bowel obstruction, head injury,
pneumothorax
▪Hypotension
▪Shock
▪COPD
▪Chest pain
▪Cyanosis
117
Nitrous oxide
–Drug interactions
▪Exacerbate dysrhythmias
–Adrenergic agonists or caffeine
▪Additive sedation and respiratory depression
–CNS depressants
▪Excessive hypotension
–Amiodarone or antihypertensive
▪Herbal/food
–St. John’s wort discontinued
118
Treatment of overdose of Nitrous oxide
▪Metoclopramide or antiemetic to reduce
associated nausea, vomiting
119
Volatile liquid general anesthetics
–_________________ pressure allows them to vaporize at low temperatures and pressures
▪Anesthesia machine delivers precisely controlled
amounts.
–Very potent but little analgesic effect
–Low vapor pressure allows them to vaporize at low temperatures and pressures
▪Anesthesia machine delivers precisely controlled
amounts.
–Very potent but little analgesic effect
120
Isoflurane (Forane)
–Therapeutic classification
–Pharmacologic classification
–Therapeutic classification
▪Inhaled general anesthetic
–Pharmacologic classification
▪GABA and glutamate receptor agonist
121
Isoflurane (Forane)
Therapeutic effects and uses
▪Induction of general anesthesia
122
Isoflurane (Forane)
–Mechanism of action
▪Unknown
▪Interacts with ________________________in brain, including glutamate and GABA receptors
▪Unknown
▪Interacts with multiple receptors in brain, including glutamate and GABA receptors
123
Isoflurane (Forane)
–Adverse effects
▪Mild nausea
▪Vomiting
▪Tremor
–Serious adverse effects
▪Malignant hyperthermia
▪Respiratory depression
▪Reduction in blood pressure
124
Isoflurane (Forane)
–Contraindications/precautions
▪Malignant hyperthermia
▪Head trauma
▪Brain neoplasms
▪Patient under age 18
▪Older patients
▪Prolonged QT interval
125
Isoflurane (Forane)
– Drug interactions
▪Coughing, breath holding, laryngospasm
–With nitrous oxide
▪Skeletal muscle weakness, respiratory depression, apnea
–Systemic polymyxin, aminoglycosides
▪Additive effects
–Skeletal muscle relaxants
▪Additive hypotension
–Antihypertensive medications
▪Dysrhythmias with adrenergic agonists
▪Discontinue levodopa 6 to 8 hours prior
126
Isoflurane (Forane)
–Treatment of overdose
▪Profound respiratory depression
▪Symptomatic until effects diminish
127
Local Anesthetics
* Block pain transmission in :
* Loss of sensation to small or limited area of the body
peripheral nerves
* Loss of sensation to small or limited area of the body
128
Local Anesthetics
* Methods of delivery:
–Topical (surface) anesthesia
–Nerve block
–Infiltration anesthesia
–Spinal anesthesia
–Epidural anesthesia
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* Two major classes of Local Anesthetics
–Esters
–Amides
▪Lower incidence of allergic reaction
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Ester-type local anesthetics
–Act by decreasing the amount of ________ that enters neuron, depress polarization, prevent conduction of pain impulse
–May be administered with epinephrine as a
vasoconstrictor
–Limit blood loss at surgical site
–Decrease amount of anesthetic absorbed systemically
sodium
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Procaine (Novocaine)
–Therapeutic classification
–Pharmacologic classification
–Therapeutic classification
▪Local anesthetic
–Pharmacologic classification
▪Ester
▪Sodium channel blocker
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Procaine (Novocaine)
–Therapeutic effects and uses
▪Spinal, epidural, and peripheral nerve blocks for
local anesthesia
133
Procaine (Novocaine)
–Mechanism of action
▪Decreases influx of sodium into neuron
–Increases threshold for depolarization
–Prevents conduction of nerve impulse
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Procaine (Novocaine)
–Adverse effects
▪Rare
–Serious adverse effects
▪Respiratory arrest
▪Anaphylaxis
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Procaine (Novocaine)
–Contraindications/precautions
▪Hypersensitivity
▪Generalized septicemia
▪Inflammation
▪Sepsis
▪Heart block
▪Hypotension
▪Hypertension
▪Altered coagulation
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Procaine (Novocaine)
–Drug interactions
▪Antagonizes antimicrobial effects of sulfonamides
▪Increased risk of hypotension
–Antihypertensives
▪Incompatible
–Aminophylline, chlorothiazide, magnesium
sulfate, phenobarbital, phenytoin, secobarbital,
sodium bicarbonate
137
Procaine (Novocaine)
–Treatment of overdose
▪Symptomatic
▪Cardiopulmonary resuscitation may be necessary
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Amide-type local anesthetics
–Less effect on : _______________
–Lower incidence of __________ reactions
–Metabolized by hepatic CYP450 enzymes
▪Exercise caution when administering large
amounts to patients with hepatic impairment
–Less effect on myocardial contractility
–Lower incidence of allergic reactions
–Metabolized by hepatic CYP450 enzymes
▪Exercise caution when administering large
amounts to patients with hepatic impairment
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Lidocaine (Anestacon, Dilocaine, Xylocaine)
–Therapeutic classification
–Pharmacologic classification
–Therapeutic classification
▪Local anesthetic
–Pharmacologic classification
▪Amide
▪Sodium channel blocker
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Lidocaine (Anestacon, Dilocaine, Xylocaine)
–Therapeutic effects and uses
▪Surface or infiltration local anesthetic agent
▪Caudal and spinal block anesthesia
141
Lidocaine (Anestacon, Dilocaine, Xylocaine)
–Mechanism of action
▪Blocks conduction of action potentials by reducing
sodium permeability
142
Lidocaine (Anestacon, Dilocaine, Xylocaine)
–Adverse effects
-Black box warning
▪Erythema
▪Pruritus
▪Dermatitis
▪Burning
▪Alteration in taste
▪Headache
▪Gingivitis
–Serious adverse effects
▪Hypotension
▪Dysrhythmias
▪CV collapse
▪Cardiac arrest
–Black box warning: significant systemic absorption
may occur with topical use.
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Lidocaine (Anestacon, Dilocaine, Xylocaine)
– Contraindications/precautions
▪Hypersensitivity
▪Seriously damaged skin from trauma, burns, eczema (topical)
▪Stokes-Adams syndrome
▪Untreated sinus bradycardia, sinoatrial, AV, or
intraventricular heart block
▪Liver or kidney disease
▪Myasthenia gravis
▪Hypovolemia
▪Debilitated patients
▪Older patients
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Lidocaine (Anestacon, Dilocaine, Xylocaine)
–Drug interactions
▪Toxic effects
–Tocainide, mexiletine
▪Decreased lidocaine activity
–Barbiturates
▪Increased pharmacologic effects
–Cimetidine, beta blockers, quinidine
145
–Treatment of overdose for Lidocaine (Anestacon, Dilocaine, Xylocaine)
▪Symptom management
146
Adjuncts to Anesthesia
Purpose:
–To enhance anesthesia
-make procedure safer/ less unpleasant
147
Preoperative medications
–Reduce -
–Reduce -
–Reduce -
–Reduce anxiety
–Reduce gastric fluid volume and acidity
–Reduce salivary and airway secretions
