Pharm Quiz 2 Flashcards
What is the goal of general anesthesia?
absence of all perceived sensations
What is the purpose of general anesthesia?
Allow detailed surgical procedures with minimal harm to patient
What was the “anesthesia” before 1846?
- Unconsciousness from strangulation or blow to head
- Drugs for pain
- Physical restraint
What was anesthesia after 1846?
- First use of ether
- Development of safer, less toxic drugs
What are the general requirements of general anesthesia?
- Loss of consciousness (perceived sensation)
- Amnesia
- Inhibition of reflexes
- Skeletal muscle relaxation
- Safe, transient, predictable
What are the stages of general anesthesia?
- Analgesia
- Excitement/delirium
- Surgical anesthesia
- Medullary paralysis
What are the general anesthetics inhalation agents?
- Halogenated liquids
- Nitrous oxide
- Other gases
What are the general anesthetic IV agents?
- barbiturates
- benzodiazepines
- opioids
Injected anesthetic take effect (BLANK) but are (BLANK) to control level
quickly
more difficult
Inhaled anesthetic take effect (BLANK) but (BLANK) to control level
slowly
easier
What is the general protocol to how general anesthesia is administered?
- Patient start with small dose of injected to get patient under quickly
- Switch to inhaled agent for duration of procedure
- Start to withdrawal inhaled agent ASAP
How is balanced anesthesia provided?
Use 2 or more agents
What is the mechanism of action for general anesthetics?
Increase inhibition or decrease excitation throughout CNS by directly effecting neuronal receptors or combo of lipid & receptor effects
What is the purpose of anesthetic adjuvants given pre/post op?
- Relax & sedate patient prior to surgery
- Reduce post-op nausea & vomiting
- Reduce of there problems related to anesthesia
What do Neuromuscular junction blockers do?
- Paralyze skeletal muscles to facilitate positioning on table, prevent spasms, allow easier mechanical ventilation
What are the 2 type of NMJ blockers?
- Depolarizing
- Nondepolarizing
How long do the effects of NMJ blockers last?
Short durations- lasting from a few minutes to an hour or so
What can NMJ blockers cause post op?
Muscle soreness
What is a very rare effect of NMJ blockers?
- Some patients may lack certain metabolizing enzymes and remain paralyzed at end of surgery
What is dissociative anesthesia?
Patient remains conscious but indifferent to surroundings
How is dissociative anesthesia achieved?
Use of ketamine or combo of antipsychotic with opioid
When is dissociative anesthesia useful?
-Diagnostic/radiologic procedures
- Dressing changes
- Emergency surgeries
What are some residual effects of general anesthesia?
-Chills/shivering
- Nausea, vomiting
- Sore throat
- Cognitive effects
What short term cognitive effects can occur from general anesthesia?
-Confusion
- Lethargy
What populations will see some possible long-term cognitive effects of general anesthesia?
In older adults and patients with comorbidites
What is the Rehabilitation concerns of general anesthetics?
- muscle soreness
- respiratory hygiene
- confusion, altered cognition
What is the goal of local anesthesia?
Interrupt nerve condition at site of application
What is the purpose of local anesthesia?
Prevent or relieve pain without loss of consciousness or systemic effects
What is the suffix of typical local anesthetics?
-Caine
What is the mechanism of local anesthetics?
-Bind to sodium channels in nerve membrane
- Inactivate sodium channels, prevent action potential conduction
How are local anesthesias administrated?
-Topical
- Transdermal
- Inflitration
- Nerve block
- Spinal/ epidural block
- Sympathetic block
- Intravenous regional anesthesia
Where is topical local anesthesia applied?
surface of skin
What is topical local anesthesia applied for?
Pain relief
Minor burns
Abraison
Prior to injections or IV insertion
How is transdermal application enhanced by?
- Electricity (iontophoresis)
- Ultrasound (Phonophoresis)
- other chemicals
Where is infiltration local anesthesia applied?
- Injected subcutaneously
- Allowed to penetrate/infiltrate into selected area
When is infiltration commonly used?
Before suturing wounds
Where are peripheral nerve blocks injected and commonly used for?
- Injected close to nerve or nerve plexus
- Commonly used for dental procedures, other minor surgeries
Where is an epidural administered?
Outside of dura
Where is a spinal block administered?
Into subarachnoid space
Where is a sympathetic block inserted to target UE?
Stellate ganglion
Where is a sympathetic block inserted to target LE?
L4, L5 chain ganglia
What is an intravenous regional anesthesia (bier block) and how does it remain in limb?
-Local anesthetic injected into venous system of affected arm or leg
- Tourniquet placed proximally to keep drug in limb
How is a continuous nerve block administered and used?
- Admin: Small catheter is implanted near peripheral nerves to a specific region
- Local anesthetic dripped slowly/continuously onto nerve
What is the pro and con of continuous nerve block?
- Pro: excellent post-op pain control
- Con: Loss of sensation, motor function, proprioception when block is in effect
What does differential nerve block effect?
Smallest (unmyelinated fibers 1st) then largest myelinated fibers
What is the typical order of functional loss with differential nerve block?
-Pain
- Temp
-Touch
- Proprioception
- Motor
What does LAST stand for in the local anesthetics?
Local anesthetic system toxicity
What are some symptoms of LAST with CNS toxicity?
-Ringing/buzzing in ears (tinnitus)
- Agitation, restlessness, seizures
- Decrease sensation in tongue and mouth, areas of skin
- Later stages: CNS depression (including respiratory depression/failure)
What are some symptoms of cardio toxicity due to LAST?
- Changes in heart rate (bradycardia)
- Other ECG abnormalities
- Clinical signs of cardiac depression (fatigue, dizziness)
- Cardiac arrest
What is the primary goal of muscle relaxants?
Selective decrease in skeletal muscle excitability
What are muscle relaxants primarily used for?
Muscle spasm spasticity
What is a muscle spasm?
- Injury to muscle, peripheral nerve
- Tonic contraction in paraspinals, traps
What is spasticity?
CNS legion
Exaggerated stretch reflex
What are some agents used to treat muscle spasm?
- Centrally acting anti-spasm drugs
- Diazepam
What are centrally-acting Antispasmodic drugs?
-Diverse groups of drugs
- used commonly in back, neck spasm, other orthopedic injuries
What is the mechanism of Central antispasm drug Carioprodol?
-Enhance GABA inhibition in brain
What is the mechanism of Central antispasm drug cyclobenzaprine?
Increase serotonin in brainstem
How does Diazepam work?
- Works in CNS to increase inhibitory effects of GABA
- Less excitation leads to muscle relaxation
What is Baclofen?
Synthetic GABA
- Stimulates receptors in cord
- Decreases excitation of alpha motor neuron
- Administered intrathecally
When is intrathecal baclofen used and how is it delivered?
- Used in severe spasticity
- Delivered by catheter and pump to deliver drug to subarachnoid space
What are some signs of intrathecal baclofen overdose?
- Decrease respiration
- Decrease cardiac function
- Stupor
- Coma
What are some signs of intrathecal baclofen withdrawal?
- Fever
- Confusion
- Hallucination
- Seizures
What is the primary agent of Alpha- 2 agonists?
Tizanidine
How do Alpha-2 agonist work?
- Stimulates alpha 2 receptors located on spinal interneruon
- Cause inhibition of interneurons (decrease excitatory input onto alpha neuron)
How does Gabapentin work?
- Inhibits Ca entry presynaptic terminals, decrease release of glutamate (other excitatory neurotransmitters)
How does Dantrolene work?
- Only direct- acting muscle relaxant
- Inhibits release of calcium from skeletal muscle SR
What is Botulinum toxin and where is it injected?
- Muscle paralytic
- Injected locally into skeletal muscle for severe spasms
What is the mechanism of botulinum toxin?
Inhibits Ach release at skeletal NMJ
When does relaxation occur and how long does it last after botulinum is injected?
- Occur within 3-7 days
- Lasts 2-3 months
What are some signs of botulinum overdose?
- Drooping eyes
- Difficulty speaking/swallowing
- General muscle weakness
- Respiratory distress
What are the agents used to treat spasticity?
- Diazepam
- Baclofen
- Alpha 2 agonist
- Gabapentin
- Dantrolene
- Botulinum toxin
