General anesthetics, local anesthetics, and muscle relaxants

Question 1

Why would general anesthetics be used rather than local?

Answer 1

used for more extensive surgeries/procedures bc the pt is unconscious

Question 2

What are the 7 things an anesthetic agent must be able to do?

Answer 2

Rapid onset of anesthesia (loss of consciousness and sensation)
Skeletal muscle relaxation (this goal is met by using a skeletal mm blocker with a general anesthetic)
Inhibition of sensory and autonomic reflexes
Easy adjustment of the anesthetic dosage during the procedure
A minimum of toxic side effects
Rapid, uneventful recovery after the drug is stopped
Amnesia (no recollection of what happened during surgery)

Question 3

If a patient is losing sensation, but is still aware of what is happening, what stage of general anesthesia are they?

Answer 3

1

Question 4

If a patient is unconscious, but they are restless and agitated, what stage of general anesthesia are they?

Answer 4

2

Question 5

What is the most desirable stage of general anesthesia for surgery?

Answer 5

3 (want to get pt here as quick as possible & stay)

Question 6

What is another name for stage 4 of general anesthesia and what are the side effects?

Answer 6

Medullary paralysis – deep – cessation of spontaneous respiration because respiratory control centers are inhibited. BP regulation is affected, cardiovascular collapse can occur. If this stage is reached respiratory and circulatory support must be provided or patient can die

Question 7

In what ways can a general anesthesia be administrated?

Answer 7

intravenous, inhaled, IV

Question 8

What is a pro & con of having inhaled general anesthetic?

Answer 8

doses can easily be adjusted based on how patient is responding, but causes increased length of time required for onset

Question 9

what drug specifically is good for short procedures with rapid recovery so able to mobilize quickly?

Answer 9

Proposal (diprivan)

Question 10

_____ drug typically given first to get the patient to stage 3 of general anesthetic and _____ is used to keep a pt there during a procedure

Answer 10

IV & inhaled

Question 11

What is the ONLY inhaled general anesthetic

Answer 11

nitrous oxide

Question 12

The pharmokinetics of general anesthetics results in the possibility of the drugs being stored where and what is the effect of that?

Answer 12

Anesthetics may become stored in adipose tissue and then will be re-released or washed out as the patient recovers from surgery – this can cause confusion, disorientation, lethargy

Question 13

How do general anesthetic work?

Answer 13

Decrease activity of neurons in the reticular activating system in the brain which causes sedation, hypnosis, and amnesia
Inhibit neuronal function in the spinal cord which causes immobility and inhibits responses to pain (such as surgery incisions)
Bind to specific receptors located on the outer surface of the CNS neurons enhancing CNS inhibition

Question 14

what are the 2 types of adjuvants (related to general anesthetics)

Answer 14

preoperative meds & neuromuscular blockers

Question 15

Why might a patient be given preoperative medications (general anesthetics) and what are some examples?

Answer 15

Helps to relax the patient and reduce anxiety before getting to the OR
Examples: Barbiturates, benzodiazepines, opioids

Question 16

Why might a patient be given neuromuscular blockers in addition to general anesthetics?

Answer 16

In order to ensure skeletal mm paralysis neuromuscular blockers and requires smaller dose of general anesthetics

Question 17

How do NM blockers work?

Answer 17

Work by blocking the postsynaptic acetylcholine receptor located at the skeletal neuromuscular junction

Question 18

Your patient had a neuromuscular blocker during surgery. What is something that a PT should be aware of?

Answer 18

residual effects of neuromuscular blockers can persist after surgery, including residual paralysis, skeletal muscle contractions remain depressed for several hours

Question 19

What is a side effect of general anesthetics that a PT should be worried about and how should it be addressed?

Answer 19

Bronchial secretions may accumulate in the lungs in patients recovering from general anesthesia due to suppressed recovering from general anesthesia due to suppressed mucociliary clearance which can lead to infections

PTs should address this through early mobilization and breathing exercises or postural drainage

Question 20

What population is at greatest risk for detrimental effects on memory, attention and cognition following surgery?

Answer 20

Most prevalent in older adults who had some cognitive decline before surgery

The degree of this is related to the type of anesthesia used, how long it was administered and how deeply the patient was sedated

Question 21

Why would local anesthetics be used vs general?

Answer 21

used when the surgery area is a small, defined area, used when the patient needs to remain conscious during surgery

Question 22

What is the primary disadvantage of local anesthetics?

Answer 22

length of time required to establish an anesthetic effect and the risk that it could be incomplete

Question 23

What is the goal of local anesthetics?

Answer 23

to block afferent nerve transmission along the peripheral nerve so that a procedure is painless

Question 24

T/F: An epidural is an example of a local anesthetic?

Answer 24

True: Can be introduced at the spinal cord and the transmission of impulses at a specific level of the cord may be blocked

Question 25

What are the dangers of a local anesthetic reaching the circulatory system?

Answer 25

confusion, agitation, excitation, seizures, decreased cardiac excitation, heart rate, and force of contractions

Question 26

When might a topical local anesthetic be used?

Answer 26

Used to reduce pain prior to minor surgical procedure (wound cleaning, circumcision, cataract surgery)

Question 27

When might a transdermal local anesthetic be used?

Answer 27

Can treat localized musculoskeletal pain – OA, LBP, fractures, and neuropathic pain

Question 28

When might a peripheral nerve block local anesthetic be used?

Answer 28

Common in dental procedures and in surgeries for the foot and hand, but can be used near near larger nerves (sciatic) or around a plexus (brachial plexus) anesthetize a larger area of UE or LE (Common after joint replacements, ligament reconstruction, and other orthopedic surgeries)

Question 29

When might a central neuronal blockade (local anesthetic) be used?

Answer 29

used whenever analgesia is needed for a large region: common during obstetrics and chronic pain relief

Question 30

When might a sympathetic blockade (local anesthetic) be used?

Answer 30

Useful with diseases such as complex regional pain syndrome as it reduces excessive sympathetic outflow to an affected extremity

Question 31

How do local anesthetics work?

Answer 31

inhibit the opening of sodium channels located on nerve membranes which blocks action potential progression along a nerve axon

Question 32

What are important side effects that you should be aware of during PT with anesthetics?

Answer 32

• don’t put modalities on transdermal patch
• if pt has continuous nerve block be aware that if you are exercising a joint the patient will not feel pain if you over stress the joint tissues
• patient receiving local anesthetic injections for treatment of chronic pain schedule the rehab immediately after each injection
  -central nerve blockade sensation may be diminished below so check sensation & strength before ambulating & be careful with STIM

Question 33

Why might a patient be taking skeletal muscle relaxants and what is their goal?

Answer 33

treat conditions where there is hyper-excitable skeletal muscles: spasticity and muscle spasms

to normalize muscle excitability without a decrease in muscle function

Question 34

T/F diazepam & centrally acting anti-spasm drugs are both antispasm drugs

Answer 34

True

Question 35

Which anti-spasm drug is most applicable for short term management due to its tolerance and dependence, withdrawal after prolonged used which can cause seizures, anxiety, and agitation

Answer 35

diazepam and centrally acting anti-spasm drugs

Question 36

How does diazepam reduce spasticity

Answer 36

Increases the inhibitory effects of GABA on alpha motor neuron activity in the spinal cord

Question 37

Centrally acting anti-spasm drugs reduce spasticity by what possibilities?

Answer 37

By inhibiting the neurons in the polysynaptic pathways these drugs could decrease alpha motor neuron excitability and cause relaxation of skeletal mm or sedation of the CNS

Question 38

What is most effective: Baclofen or intrathecal baclofen & why?

Answer 38

Baclofen intrathecal because its injected directly into the subarachnoid space at a specific SC level & can have smaller doses due to injection site

Question 39

Which drug has less side effects and why? Baclofen or intrathecal baclofen?

Answer 39

intrathecal baclofen because the drug stays in the area injected and there is less chance it gets into systemic circulation

Question 40

T/F: There is a small window between baclofen that reduces spasticity and when it begins to inhibit voluntary motor function

Answer 40

True

Question 41

What is the only mm relaxant that effects skeletal muscle cell directly thus is used to treat severe spasticity but not spasms

Answer 41

Dantrolene Sodium

Question 42

What drug is this based on the facts below:
OG developed as an anti-seizure drug
Trade name is Neurontin
Decreases spasticity associated with SCI and MS
Also used to treat neuropathic pain
Side effects: sedation, fatigue, dizziness, and ataxia

Answer 42

Gabapentin

Question 43

Why might a doctor prescribe tizandine for muscle spasm rather than baclofen or those alike?

Answer 43

has milder side effects and less mm weakness so would be better to maintain adequate strength for functional movements

Question 44

T/F Tizandine is used following both acute brain injury and cerebral lesions

Answer 44

False: It might slow the recovery of an acute brain injury

Question 45

What form of botulinum toxin is most commonly used & what is it common name?

Answer 45

Type A: Botox

Question 46

How does botulinum toxin work?

Answer 46

Decreases mm excitation by disrupting synaptic transmission at the neuromuscular junction creating control over localized hyper-excitability

Question 47

How often would a patient need to get botox injections?

Answer 47

Within 3 months as sx return

Question 48

Why can only 1-2 mm be injected with botox?

Answer 48

it can become toxic

Question 49

What conditions can botox be used for?

Answer 49

reduce spasticity in specific mm due to CP, TBI, CVA, and SCI
Injecting it into the bladder detrusor mm can help those with stress urinary incontinence
Also used to treat those with chronic pain syndrome, migraines, neuropathic pain

Question 50

What are the goals of therapy when it comes to a patient on muscle relaxant drugs?

Answer 50

PT should perform aggressive therapy when drugs have created decrease in spasticity so that optimal motor function can be achieved so drugs can be discontinued as quickly as possible.