Lecture 3 Flashcards
1
Q
General Anesthesia
A
- Reversible state of unconsciousness
2
Q
Induction Stages of general anesthesia
A
Stage 1: Analgesia - lost somatic sensation
Stage 2: Excitement (delirium) - patient unconscious
Stage 3: Surgical anesthesia
Stage 4: Medullary paralysis - too much anesthesia
3
Q
Inhaled anesthetics
A
- easily be mixed with air or oxygen
- endotracheal tube or a mask
- easy adjustment of rate and concentration
- advanced tracking / feedback systems
4
Q
Barbiturates
A
fast onset
5
Q
Benzodiazepines
A
“Pam” endings - to induce or maintain general anesthesia
6
Q
Ketamine
A
- Dissociative anesthesia
7
Q
Propofol
A
- Short acting hypnotic that takes effect rapidly
- maintain anesthesia
- recovery may be most rapid, good for early mobilization
8
Q
Symptoms of recovering from anesthesia
A
- confusion
- disorientation
- lethargy
9
Q
Elimination and biotransformation primarily though?
A
elimination through the lungs and biotransformation in the liver
10
Q
Mechanism of action
A
- Widespread CNS inhibition through binding to 1 or more neuronal receptors in the CNS
- influenced by receptor selectivity / location
11
Q
Antihistamines
A
- sedation and antiemesis
12
Q
Anti inflammatory steroid
A
- to improve post-op pain and vomiting
13
Q
What is essential for surgical procedures? and how does it work?
A
- Skeletal muscle paralysis is essential
- work by blocking postsynaptic acetylcholine receptor
14
Q
Side effects of Neuromuscular blockers include
A
- cardiovascular problems (tachycardia)
- Increased histamine release
- residual muscle pain and weakness
- immunological reactions such as anaphylaxis
15
Q
Residual effects
A
In-patient PTs
Post-op in out-patient
Pre-op in out-patient
16
Q
Post-op effects of anesthesia
A
- confusion/delirium post-op
- muscle weakness
- airways, bronchial secretions and muscle issues
17
Q
Local anesthesia
A
- loss of sensation in a specific body part or region
- rapid recovery and lack of residual effects
- Disadvantages: takes longer to have an effect
18
Q
Local anesthesia with use of topicals/ patches should be careful during
A
- Exercise
- Manual therapy
- No heat agents
19
Q
Scheduling sessions while anesthetic is in effect
A
- reestablish normal sympathetic function and blood flow
20
Q
Local anesthetics is chosen based on
A
- location
- nature of procedure
- patient health
- patient size
- duration of action
21
Q
Spinal anesthesia can be
A
a single peripheral nerve block
22
Q
Routes of administration of local anesthesia
A
- Topical
- Transdermal
- Peripheral nerve block
- Central neural blockade
- Sympathetic blockade
23
Q
Pharmacokinetics of local anesthetics
A
- can be cardiotoxic in the bloodstream
- sometimes used with vasoconstricting agent
- metabolized in the liver
- kidneys excrete metabolites
24
Q
Differences of local anesthetics lie in?
A
administration routes
25
Topical administration
- Symptomatic relief of minor surface irritation / injury
- Applied directly to skin / mucous membranes
26
Transdermal administration
- Iontophoresis / Phonophoresis
- Transdermal Patch
- No heat agents!
27
Peripheral nerve block
- Anesthetic is injected close to the nerve trunk
- The higher up the more it blocks
- can be used postoperatively with join replacements
28
For peripheral nerve block, what do PTs need to know?
- what a specific nerve block means for the session
- need to report excessive muscle pain and signs of infection
29
Central neural blockade
- injected into the spaces surrounding the spinal cord
- Epidural nerve block: into the epidural space
- Caudal block: Lumbar epidural space through the sacral hiatus
- Spinal nerve block: subarachnoid space
30
Where can you do Central neural blockade
- could be done anywhere in the spine but usually lumbar levels
31
Sympathetic block
- riskier block
- especially useful in complex regional pain syndrome (CRPS)
- reduce sympathetic outflow to affected extremity
- block usually occurs with peripheral and central blocks
32
Local anesthetics inhibit?
- the opening of sodium channels located on nerve membranes
- blocking action potential propagation along neuronal axons
33
Anesthetic needs to affect?
- Just one specific segment to prevent sensory or motor information from being transmitted through the blocked point
34
The ability of a local anesthetic dose to block specific nerve fibers groups depend on?
- size (diameter) of the fibers
35
Fiber sensitivity to anesthetic effects
- Smaller: most sensitive
- Larger: least sensitive
* Different sizes transmit different information
36
What is the intent of a local anesthetic?
produce a regional effect on specific neurons
37
Local anesthetics can sometimes be absorbed into?
general circulation and can be toxic
38
Systemic effects of local anesthetics
- Local anesthetic systemic toxicity (LAST)
- Mostly CNS and cardiac issues
- More likely to occur with high doses, increased absorption, drug injected into systemic circulation
39
Skeletal muscle relaxants
- Treat hyperexcitable skeletal muscle - spasticity and muscle spasms
- normalize muscle excitability without a decrease in muscle function
40
Long term muscle relaxant use is not?
- practical due to addictive properties, tolerance, and physical dependence
41
Spasticity
- exaggerated muscle reflex and neurological tone
- usually related to CNS injuries
- Abnormal reflex activity that is velocity dependent
42
Spasm
- Increased muscle tension which is involuntary
- usually an orthopedic or nerve root issue
43
Antispasm drugs: Diazepam (Valium)
- likely works by interacting in both the spinal cord and the brain
- More sedative effect
- used for both spasm and spasticity
- can cause tolerance and physical dependence
44
Antispasm drugs: other
- Polysynaptic inhibitors: work in the spinal cord to reduce pain
- Increase sedation in the CNS → generalized sedation → Skeletal muscle relaxation
- Short term relief of muscle spasms
- Controlled substances
45
Antispasticity drugs: Baclofen
- Does not penetrate blood-brain barrier
- Inhibitory effect on alpha motor neurons in the spinal cord
- Decreased firing of the alpha motor neuron with subsequent relaxation of the skeletal muscle
- Used orally for spasticity associated with lesions of the spinal cord
- Less generalized muscle weakness than dantrolene
- can also be used to treat alcohol abuse
46
Intrathecal baclofen
- severe, intractable spasticity
- specific level of the spinal cord
- * increased effectiveness, smaller doses
- fewer systemic side effects
- May also interrupt chronic pain pathways
47
Antispasticity drugs: Dantrolenen sodium (Dantrium)
- only muscle relaxant that exerts effect directly on the skeletal muscle
- inhibits channel opening, reduces muscle contraction, enhances relaxation
- not used to treat MSK injury / related spasms or tension
- side effects → generalized muscle weakness, hepatotoxicity, drowsiness, dizziness, nausea, diarrhea
48
Antispasticity drugs: Gabapentin (neurontine)
- Effective in decreasing the spasticity associated with SCI and MS
- neuropathic pain
- side effects → sedation, fatigue, dizziness, and ataxia
49
Tizanidine
- Pre and postsynaptic inhibition of alpha-2 receptors in the CNS
- Used to control spasticity resulting from spinal lesions, sometimes in cerebral lesions
- Treat chronic headaches and chronic pain
- Side effects → sedation, dizziness, dry mouth, but less cardiac side effects
50
Botulinum Toxin ( Botox)
- Controls localized muscle hyperexcitability
- Loss of presynaptic acetylcholine release results in paralysis of the muscle fiber → disrupting synaptic transmission at the NMJ
- Help to reestablish a more reasonable level of excitation at the cord level
- Treat muscle Dystonias
- Symptoms may return in 2 to 3 months
