Intrathecal Key Concepts and Techniques 29 May 25 Flashcards
(121 cards)
1
Q
Where are the veins located in the epidural space?
A
Lateral component
The lateral location of veins is clinically significant for determining midline placement when inserting a needle.
2
Q
What is the landmark used to ensure midline placement during spinal and epidural procedures?
A
Spinous process
The spinous process serves as a guide for accurate needle placement in the midline.
3
Q
What is the clinical significance of seeing continuous blood flow when inserting a needle in the epidural space?
A
Indicates the needle is not at midline
Continuous blood flow suggests the needle has hit a lateral vein rather than being positioned correctly at midline.
4
Q
What is flica mediana dorsalis?
A
Connective tissue dividing the epidural space
This tissue can contribute to unilateral blocks during anesthesia.
5
Q
What is the subarachnoid space also known as?
A
Intrathecal space
The subarachnoid space is where local anesthetics are administered for spinal anesthesia.
6
Q
What components are found in the subarachnoid space?
A
- Cerebrospinal fluid (CSF)
- Nerve roots
- Spinal cord
These components are crucial for achieving sensory blockade during spinal anesthesia.
7
Q
What is the primary concern when administering spinal anesthesia?
A
Sensory blockade
The goal is to prevent the patient from feeling pain during surgical procedures.
8
Q
How is sensory blockade typically tested during spinal anesthesia?
A
Using cold sensation tests, such as alcohol swabs
Cold sensation testing helps confirm that the sensory blockade is effective.
9
Q
What is the significance of the pia mater in spinal anesthesia?
A
Reabsorbs local anesthetic
The pia mater’s role in reabsorption can affect the duration and effectiveness of the anesthetic.
10
Q
What are the three layers of meninges from outermost to innermost?
A
- Dura mater
- Arachnoid mater
- Pia mater
Understanding the layers is important for spinal procedures and anesthesia administration.
11
Q
How many cervical nerves are there?
A
Eight cervical nerves
This is important for understanding the anatomy relevant to spinal anesthesia.
12
Q
What dermatome level is associated with the nipple area?
A
T4
Knowing dermatome levels is essential for effective sensory blockade during procedures.
13
Q
What provides sensory innervation to the face?
A
Cranial nerve number five (Trigeminal nerve)
This is relevant for understanding airway blocks and regional anesthesia considerations.
14
Q
What are the three branches of the trigeminal nerve?
A
- V1 (Ophthalmic)
- V2 (Maxillary)
- V3 (Mandibular)
These branches are important for regional anesthesia in facial procedures.
15
Q
What is the potential consequence of administering local anesthetic in the subdural space?
A
Ineffective block leading to high cranial spread
Mistakes in placement can result in serious complications.
16
Q
What is the primary concern when local anesthetic is placed in the epidural space?
A
Achieving effective sensory blockade
Proper placement is crucial for the success of the procedure.
17
Q
True or False: The subdural space contains veins.
A
False
The subdural space is similar to the epidural space but lacks veins.
18
Q
What is the significance of dermatome levels in nursing procedures?
A
Dermatome levels are crucial for determining sensory blockade during procedures like spinal anesthesia.
Understanding dermatome levels helps in effectively administering anesthesia and managing patient care in surgical settings.
19
Q
What is the typical injection site for local anesthetic in a spinal block?
A
L4-L5 or L3-L4.
These sites are commonly used for spinal anesthesia to achieve the desired sensory blockade.
20
Q
What is differential blockade in the context of spinal anesthesia?
A
Differential blockade refers to the ability to achieve varying levels of sensory blockade despite the injection site.
This technique allows for targeted anesthesia based on the surgical procedure being performed.
21
Q
What is the typical sensory blockade level required for a C-section?
A
T4.
This level ensures adequate anesthesia for the surgical area during a Cesarean section.
22
Q
What should a CRNA prepare ahead of time when administering spinal anesthesia?
A
Drugs and general anesthesia setup.
Being prepared with necessary medications and equipment is critical in case of emergencies during the procedure.
23
Q
What are the potential consequences of a spinal block that reaches T4?
A
It can lead to hypotension and bradycardia.
Monitoring blood pressure and heart rate is essential to prevent complications during anesthesia.
24
Q
Which drug is typically chosen for hypotension during spinal anesthesia?
A
Ephedrine.
Ephedrine is commonly used to manage hypotension due to its vasopressor effects.
25
What is the role of local anesthetic volume in epidural anesthesia?
Volume is crucial for achieving effective anesthesia in the epidural space.
## Footnote
Unlike spinal anesthesia, where dosages are smaller, epidural anesthesia requires careful volume management.
26
What are the two types of solutions discussed in relation to local anesthetics?
Hyperbaric and isobaric.
## Footnote
These solutions affect the spread of local anesthesia within the cerebrospinal fluid.
27
What does the spread of local anesthetic in the subarachnoid space resemble?
Cream spreading in coffee.
## Footnote
This analogy helps visualize how local anesthetic disperses in the cerebrospinal fluid.
28
What factors can affect the height of sensory blockade during spinal anesthesia?
Patient position, baricity of the solution, and dosage of local anesthetic.
## Footnote
Understanding these factors is essential for achieving the desired anesthesia level.
29
What is the typical sensory blockade level for knee and hip surgery?
T10.
## Footnote
Knowing the appropriate sensory blockade level is vital for effective pain management during orthopedic surgeries.
30
Fill in the blank: The first thing to know for hysterectomy anesthesia is _______.
T6.
## Footnote
This level is important for ensuring adequate anesthesia during a hysterectomy.
31
True or False: It is acceptable to put the endotracheal tube in the esophagus as long as you recognize it.
True.
## Footnote
Recognizing the placement of the tube is crucial, as it allows the practitioner to correct the mistake.
32
What is the importance of the vocal cords' appearance during intubation?
They should appear white and inverted V-shaped.
## Footnote
Proper visualization of the vocal cords is essential for successful intubation.
33
What should CRNA students focus on during their training?
Hands-on practice and proficiency in procedures like intubation and anesthesia administration.
## Footnote
Practical experience is critical for developing skills necessary for patient safety and effective anesthesia care.
34
What is the significance of knowing the half-life of muscle relaxants?
It helps in managing patient recovery and avoiding prolonged sedation.
## Footnote
Understanding drug half-lives is essential for effective anesthesia management.
35
What is the primary focus for a new CRNA student?
Understanding local anesthesia and working well with their CRNA.
## Footnote
Emphasis on the importance of collaboration and learning from experienced CRNAs.
36
What is the significance of the site of injection in local anesthesia?
It determines the height and spread of the anesthesia.
## Footnote
The choice of injection site affects how far the anesthetic will travel in the body.
37
Why is the L3-L4 space preferred for injection over L4-L5?
L3-L4 has a bigger gap between spinous processes, making it easier to insert the needle.
## Footnote
The anatomy of the vertebrae impacts the ease of access for injection.
38
What is barbotage in the context of spinal anesthesia?
The technique of mixing local anesthetic with CSF by aspirating and reinjecting.
## Footnote
Barbotage is believed to enhance the mixing of anesthetic, though evidence on its effectiveness is debated.
39
True or False: The speed of injection affects the spread of local anesthetic.
False.
## Footnote
Data suggests that the speed of injection does not significantly affect the spread of the anesthesia.
40
What position should the patient assume for optimal spinal anesthesia injection?
Curved back towards the provider, often referred to as the 'Halloween cat' position.
## Footnote
This position helps in accessing the lumbar spine effectively.
41
What is the relationship between CSF volume and local anesthetic spread?
Lower CSF volume leads to higher spread of local anesthetic.
## Footnote
Factors like pregnancy and age can reduce CSF volume, affecting anesthesia distribution.
42
Fill in the blank: The higher the volume of local anesthetic injected, the more likely it is to reach _______.
T4 level.
## Footnote
This is particularly relevant in epidural anesthesia where the goal is to achieve specific sensory levels.
43
What gauge needles are typically used for spinal anesthesia?
22 to 25 gauge needles.
## Footnote
These needles are small to minimize patient discomfort during the procedure.
44
Which factor significantly impacts the spread of local anesthetic in epidural anesthesia?
Volume of the local anesthetic.
## Footnote
Higher volumes are necessary to achieve the desired sensory level.
45
What is the typical pKa range for chloroprocaine, a local anesthetic?
Around 8 to 9.
## Footnote
The pKa affects the speed of onset for local anesthetics.
46
Why does chloroprocaine work faster than lidocaine despite its higher pKa?
Chloroprocaine has a higher concentration (2-3%) compared to lidocaine.
## Footnote
Higher concentration contributes to faster onset despite the pKa values.
47
What is the effect of pregnancy on local anesthesia?
Pregnancy increases intra-abdominal pressure, affecting CSF volume and anesthesia spread.
## Footnote
Changes during pregnancy can complicate the administration of anesthesia.
48
What should be done before administering an epidural?
Numb the back with lidocaine.
## Footnote
This step minimizes discomfort during the epidural needle insertion.
49
How does the bevel orientation of a needle affect anesthesia administration?
Bevel up is preferred to potentially enhance height of spread, though evidence is inconclusive.
## Footnote
Common practice among CRNAs is to orient the bevel upwards during injection.
50
What is the primary goal when administering an epidural for a C-section?
To achieve sensory blockade at the T4 level.
## Footnote
This level is crucial for adequate anesthesia during the procedure.
51
What is the concentration of local anesthesia typically used?
2% and 3%
## Footnote
Concentrations like 0.125% are not standard for local anesthesia.
52
Does pregnancy affect the spread of local anesthetics in epidurals?
No
## Footnote
Pregnancy does not affect the spread of local anesthetics in epidurals since CSF is not involved.
53
What position can help alleviate pain during epidural anesthesia?
Positioning the patient to the side of the pain
## Footnote
For example, if pain is on the right side, position the patient on the right side.
54
What is the significance of the cervix being 10 cm open?
It indicates readiness for the baby to come out
## Footnote
10 cm is the required dilation for delivery.
55
What should be given if a patient is in pain during labor with an epidural?
Opioids like fentanyl or sufentanil
## Footnote
Local anesthetics may impair the ability to push.
56
What are additives in epidural anesthesia intended to do?
Enhance pain control but not increase spread
## Footnote
Examples include fentanyl and Remifentanil.
57
True or False: Speed of injection affects the spread of local anesthetic in epidurals.
False
## Footnote
The spread is determined by the local anesthetic's diffusion in the epidural space.
58
What is differential blockade?
The sensitivity of different nerve fibers to local anesthesia
## Footnote
Certain fibers are affected before others when local anesthetics are administered.
59
Which nerve fibers are blocked first by local anesthetics?
B fibers
## Footnote
B fibers are responsible for autonomic functions and are affected before C and A fibers.
60
What is the order of nerve fiber blockade by local anesthetics?
* B fibers
* C fibers
* A delta fibers
* A alpha, beta, gamma fibers
## Footnote
This order reflects the sensitivity of the fibers to local anesthesia.
61
How does the sensory level relate to motor blockade in spinal anesthesia?
Sensory level is typically two levels higher than motor blockade
## Footnote
For example, if motor blockade is at T8, sensory will be at T6.
62
What is the clinical significance of the differential blockade?
Understanding which fibers are blocked helps manage patient comfort during surgery
## Footnote
It allows anesthesia providers to ensure pain relief while maintaining motor function.
63
What is the role of sympathetic fibers in relation to sensory and motor levels?
Sympathetic fibers are blocked higher than sensory levels
## Footnote
They can be 2 to 6 segments higher than sensory levels.
64
What should you do if a patient is still moving during spinal anesthesia?
Wait until movement is blocked before proceeding
## Footnote
This ensures adequate anesthesia before surgery.
65
What is the importance of positioning during labor with an epidural?
It can direct the spread of anesthesia
## Footnote
Correct positioning can help manage pain effectively.
66
What is a common challenge when placing an epidural needle?
Difficulty due to the anatomy of the thoracic spine
## Footnote
The spinous processes can make needle placement challenging.
67
What is the typical size of an epidural needle?
18 gauge
## Footnote
This size allows for the visibility of the bevel during placement.
68
How should the bevel of the catheter be oriented for higher spread?
Point the bevel up
## Footnote
This helps direct the catheter to the desired area.
69
What is the recommended volume of saline to use after loss of resistance in epidural placement?
10 cc
## Footnote
This volume helps create space for the local anesthetic.
70
What factors influence the effectiveness of an epidural?
* Patient positioning
* Concentration of local anesthetic
* Additives used
## Footnote
These factors can impact the spread and effectiveness of the anesthesia.
71
What is the sensory level in relation to spinal anesthesia?
The sensory level is two levels higher than the water level, starting from T8.
72
What is the motor blockade level when starting from T8?
The motor blockade level is at T10.
73
How high can the sympathectomy reach in relation to sensory levels?
The sympathectomy can reach two to six levels higher than sensory levels, as high as T2.
74
What are expected outcomes associated with spinal anesthesia?
Hypertension and bradycardia are expected outcomes.
75
What is the role of the cardio accelerator nerve in spinal anesthesia?
The cardio accelerator nerve is involved in T1 to T4, potentially causing bradycardia.
76
What should be done if hypotension is observed within five minutes of anesthesia administration?
Start giving fluids and potentially vasopressors.
77
What is the goal sensory level for hip and knee replacement surgeries?
The goal sensory level is T10.
78
What is the importance of monitoring vital signs after administering spinal anesthesia?
Vital signs should be monitored every three minutes for the first 30 minutes to track trends.
79
What is the first type of nerve to be blocked when initiating spinal anesthesia?
The first nerve type to be blocked is the B fiber.
80
What is the Bromage scale used for?
The Bromage scale is used to measure motor block from 0 to 3, where 0 means no motor block and 3 means complete motor block.
81
What cardiovascular effects are associated with spinal anesthesia?
* Decreased preload due to sympathectomy
* Decreased afterload due to vasodilation
* Initially normal cardiac output that decreases over time
* Bradycardia due to T1 to T4 blockade
82
What is tachyphylaxis in relation to ephedrine administration?
Tachyphylaxis means that the initial dose will become less effective over time, requiring higher doses.
83
What are two methods of fluid management during spinal anesthesia?
* Preloading
* Co-loading
84
Fill in the blank: The first sign of local anesthesia working is _______.
hypotension
85
True or False: The recovery of nerve function after anesthesia starts with the A fibers.
False
86
What should be done to prevent hypotension and bradycardia during spinal anesthesia?
Consider prophylactic administration of vasopressors like neosynephrine.
87
What is the significance of the vessel gyrus reflex?
It is a protective mechanism that can cause bradycardia when T1 to T4 is blocked.
88
What is the expected outcome of administering ondansetron during spinal anesthesia?
It can help prevent hypotension and bradycardia.
89
What are the two main techniques of fluid management discussed?
Co-loading and pre-loading
## Footnote
Co-loading involves administering fluids during the procedure, while pre-loading involves administering isotonic solutions before the procedure.
90
Define pre-loading in fluid management.
Administering isotonic solutions 30 minutes before a procedure
## Footnote
Pre-loading typically involves 500-750 cc of normal saline to prepare the patient for anesthesia.
91
What is co-loading in fluid management?
Administering fluids during the procedure using a pressure bag
## Footnote
Co-loading aims to provide at least 15 mL per kg of fluid during the procedure.
92
What is the main concern when using fluid management techniques in patients with preeclampsia?
Risk of decreased blood pressure due to fluid overload
## Footnote
Patients with preeclampsia are often treated with magnesium sulfate, which can lower blood pressure.
93
What is the common practice for fluid management before a spinal anesthesia procedure?
Pre-loading with fluids is the most common practice
## Footnote
It is important to ask the clinical team about their specific practices regarding fluid prophylaxis.
94
What is the effect of positioning on hypotension during spinal anesthesia?
Tilting the patient to the left relieves aortic compression
## Footnote
This helps improve preload by relieving pressure on the inferior vena cava.
95
True or False: Delayed treatment of hypotension can increase mortality.
True
## Footnote
Early intervention is crucial to prevent significant complications in patients experiencing hypotension.
96
What are the common medications used to treat hypotension and bradycardia in the operating room?
Ephedrine and phenylephrine
## Footnote
These medications are often used in conjunction with fluid management.
97
What is the role of anticholinergic agents in treating bradycardia during anesthesia?
They antagonize parasympathetic effects to increase heart rate
## Footnote
Atropine and glycopyrrolate are common anticholinergic agents used.
98
What is a potential pulmonary effect of spinal anesthesia?
Small decrease in vital capacity
## Footnote
This is particularly concerning for patients with COPD or other respiratory conditions.
99
What positioning is recommended for morbidly obese patients experiencing difficulty breathing after spinal anesthesia?
Semi-Fowler's position
## Footnote
This position can alleviate respiratory distress without compromising sterility.
100
What is the parasympathetic effect on the GI tract?
Increased peristalsis and sphincter relaxation
## Footnote
The parasympathetic nervous system enhances digestive processes.
101
What is the sympathetic effect on the GI tract?
Inhibition of peristalsis and gastric secretions
## Footnote
The sympathetic nervous system suppresses digestive functions.
102
How does spinal anesthesia affect urinary function?
Causes relaxation of urinary sphincter tone
## Footnote
Sympathetic blockade at T10 can influence urinary retention and sensation.
103
What is the impact of spinal anesthesia on postoperative illness?
Reduction of the incidence of postoperative illness
## Footnote
This is a significant benefit compared to general anesthesia.
104
Fill in the blank: The main arterial blood pressure must be maintained to avoid changes in the _______.
Urinary system
105
What is the effect of opioids on the urinary system during spinal anesthesia?
Decreased contraction of bladder muscles
## Footnote
This may lead to increased bladder capacity and reduced sensation to void.
106
What happens to urinary sphincter tone during spinal or epidural anesthesia?
Urinary sphincter tone relaxation occurs
## Footnote
This can lead to a full bladder in patients.
107
How do opioids affect the GUT system?
Opioids decrease contraction, reducing the sensation to urinate
## Footnote
This can result in a full bladder in patients.
108
Why do patients with regional anesthesia stay longer in recovery?
Because they may have a full bladder
## Footnote
Nurses perform urinary scans before discharge.
109
Which metabolic effects are important in the context of regional anesthesia?
Cardiovascular and pulmonary effects
## Footnote
Endocrine and metabolic effects are also significant.
110
What happens to cortisol and epinephrine levels with regional anesthesia?
They are antagonized
## Footnote
This results in no elevation of these hormones.
111
What is the structure of a tertiary amine?
It has three branches
## Footnote
A quaternary amine has four branches.
112
What is the significance of the intermediate chain in local anesthetics?
It is responsible for drug classification and metabolism
## Footnote
It also influences allergic potential.
113
Which type of local anesthetic has a higher allergic potential?
Esters
## Footnote
This is due to para-aminobenzoic acid.
114
Is there cross-sensitivity between esters and amides?
Yes, there is cross-sensitivity with esters but not with amides
## Footnote
Amides have a decreased allergic reaction potential.
115
What factors affect the onset of local anesthesia?
Dependent on the pKa
## Footnote
Chloroprocaine is an exception.
116
What determines the potency of local anesthetics?
Lipid solubility
## Footnote
All local anesthetics have a benzene ring contributing to this.
117
What influences the duration of action of local anesthetics?
Protein binding
## Footnote
Alpha-1 acid glycoprotein plays a role.
118
Where does local anesthetic block occur?
Inside the cell
## Footnote
It requires entering in a non-ionized form.
119
How does the injection site affect local anesthetic concentration?
IV injections have higher concentration than subcutaneous
## Footnote
This affects the likelihood of toxicity.
120
How are esters metabolized?
In plasma
## Footnote
Amides are metabolized in the liver.
121
What are the three types of local anesthetics based on density?
Hypobaric, isobaric, hyperbaric
## Footnote
These classifications affect their use in procedures.
