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Questions and Answers
What is the primary method used to locate the epidural space during epidural anesthesia?
What is the primary method used to locate the epidural space during epidural anesthesia?
What is the main purpose of inserting a catheter into the epidural space?
What is the main purpose of inserting a catheter into the epidural space?
Which characteristic of the Tuohy’s needle is specifically designed to prevent dural puncture?
Which characteristic of the Tuohy’s needle is specifically designed to prevent dural puncture?
What happens when the needle pierces the ligamentum flavum and enters the epidural space?
What happens when the needle pierces the ligamentum flavum and enters the epidural space?
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What gauge is the typical Tuohy’s needle used in epidural anesthesia?
What gauge is the typical Tuohy’s needle used in epidural anesthesia?
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What is the primary purpose of local infiltration anesthesia?
What is the primary purpose of local infiltration anesthesia?
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Which of the following local anesthetics is typically used for brachial plexus block?
Which of the following local anesthetics is typically used for brachial plexus block?
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At which vertebral level should a spinal anesthesia puncture be performed?
At which vertebral level should a spinal anesthesia puncture be performed?
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Which technique can be utilized to locate nerves for a regional block?
Which technique can be utilized to locate nerves for a regional block?
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What is an important consideration when preparing for spinal anesthesia?
What is an important consideration when preparing for spinal anesthesia?
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What anatomical landmark is typically used as a guide for spinal anesthesia puncture?
What anatomical landmark is typically used as a guide for spinal anesthesia puncture?
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How long does bupivacaine (0.5%) typically last when used for nerve blocks?
How long does bupivacaine (0.5%) typically last when used for nerve blocks?
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What is the maximum recommended dose of xylocaine (1-2%) for nerve blocks?
What is the maximum recommended dose of xylocaine (1-2%) for nerve blocks?
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What is the primary characteristic of the sitting position for lumbar puncture?
What is the primary characteristic of the sitting position for lumbar puncture?
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What is the recommended action after verifying the tip of the spinal needle is in the subarachnoid space?
What is the recommended action after verifying the tip of the spinal needle is in the subarachnoid space?
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Which approach may be attempted for lumbar puncture when the patient has densely calcified ligaments?
Which approach may be attempted for lumbar puncture when the patient has densely calcified ligaments?
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What is the significance of positioning the needle bevel parallel to the fibers of the ligamentum flavum and dura?
What is the significance of positioning the needle bevel parallel to the fibers of the ligamentum flavum and dura?
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What primary technique is emphasized during the lumbar puncture procedure?
What primary technique is emphasized during the lumbar puncture procedure?
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In the paramedian approach for lumbar puncture, where is the needle introduced?
In the paramedian approach for lumbar puncture, where is the needle introduced?
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What happens when the local anesthetic agent is injected after CSF aspiration?
What happens when the local anesthetic agent is injected after CSF aspiration?
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Why might the sitting position be hazardous for a sedated patient during lumbar puncture?
Why might the sitting position be hazardous for a sedated patient during lumbar puncture?
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Study Notes
Regional Anesthetic Techniques
- Regional anesthetic techniques involve injecting anesthetic drugs near nerves, ganglia, or plexuses to block pain signals.
- Types of regional anesthetic techniques include surface (topical), local infiltration, nerve block, ganglion block, plexus block, central neuronal block (spinal and epidural), and local intravenous anesthesia.
Local Infiltration Anesthesia
- Local infiltration involves injecting the local anesthetic (LA) drug around the affected area (like a lipoma), blocking nerve endings.
- Commonly used LA drugs are xylocaine (0.5-1%) and bupivacaine (0.25%).
Nerve or Plexus Blocks
- Nerve or plexus blocks involve injecting LA around nerve trunks, to numb the area served by those nerves.
- The procedure's name relates to the specific area injected (e.g., brachial plexus block, median nerve block).
- Xylocaine (1-2%, lasting 1-1.5 hours, max dose 400-500 mg) and bupivacaine (0.5%, lasting 5-7 hrs, max dose 200 mg) are commonly used.
- Techniques for nerve localization include anatomical landmarks, peripheral nerve stimulation, and ultrasound (US).
Spinal Anesthesia (Intrathecal or Subarachnoid Block)
- Spinal anesthesia involves injecting the LA into the subarachnoid space below the spinal cord, to numb the lower half of the body.
- The spinal cord extends to the second lumbar vertebra (L2), and the dura sac extends to the second sacral vertebra (S2).
Anatomical Considerations
- The vertebral column consists of 33 vertebrae (7 cervical, 12 thoracic, 5 lumbar, 5 sacral, 4 coccygeal).
- The subarachnoid space between L2 and S2 contains CSF and nerve roots (cauda equina).
- Spinal anesthesia can be performed only below the L2 vertebra.
- The highest point of the iliac crest is typically at the level of the L4 spinous process (L4-L5 interspace).
Preparations for Spinal Anesthesia
- Preoperative assessment, including explaining the technique.
- Providing adequate sedation.
- Inserting an IV line and giving preloading fluids.
- Monitoring vital signs during the procedure.
- Preparing for general anesthesia if needed.
Technique of Spinal Anesthesia
- Apply antiseptic (betadine) to the skin.
- Remove excess antiseptic with sterile gauze.
- Use a small gauge needle to give local anesthesia before the spinal puncture.
- Use sterile spinal needles, syringes, and LA drugs.
- Arrange all equipment on a sterile trolley before the puncture.
Patient's Position
- Sitting position: The most common for lumbar puncture (LP), easier to perform LP and identify landmarks (helpful for obese patients).
- Lateral position: Useful when the patient can't sit, or when sedation makes sitting risky.
Puncture
- Position the patient with a flexed spine to separate the spinous processes, creating space for the needle.
- Perform the procedure under aseptic conditions.
- Identify the injection site (intervertebral space) using anatomical landmarks.
- Inject the LA.
Spinal Needle Advancement
- Advance the spinal needle with its stylet in place, perpendicular to the skin, aiming slightly cephalad.
- Remove the stylet to ensure the needle is in the subarachnoid space (check for CSF flow).
- Inject the LA after confirming the subarachnoid space.
- After injecting, withdraw the needle and syringe.
- Move the patient to the supine position.
A-Midline Approach
- Anatomical approach involving skin, subcutaneous tissue, supraspinous, interspinous ligaments, ligamentum flavum, epidural space, dura mater, and arachnoid mater on the midline.
B-Paramedian or Lateral Approach
- A slight lateral approach, 1cm lateral to the midline, allowing the needle to penetrate the dura on the midline.
- Includes similar anatomy as the midline approach, but focuses on the paravertebral muscles.
Directions of the Spinal Needle Bevel
- The needle bevel should be parallel to the ligamentum flavum and dura fibers to split the fibers, reducing the chance of CSF leak and post-dural puncture headache.
Epidural Anesthesia
- Epidural anesthesia is a central neuronal block where LA solution is injected into the epidural space outside the dura mater, where the spinal nerve roots pass.
What is the Epidural Space?
- The epidural space is between the dura mater and the ligamentum flavum, outside the spinal cord.
Techniques of Epidural Anesthesia
- The loss of resistance technique is used to locate the epidural space.
- An epidural needle is advanced through the skin and advanced until the spinal ligaments are detected.
- The stylet is removed and an air or saline-filled syringe is attached.
- Slowly advance the needle, when the needle pierces the ligamentum flavum, and there is no resistance, the epidural space is found.
Epidural Procedures: Single Dose vs. Catheter
- A short procedure requires a single dose of LA.
- Longer procedures or when postoperative analgesia is needed, a catheter is inserted for continuous epidural analgesia.
Epidural Needle: Tuohy's Needle
- The standard epidural needle is the Tuohy's needle.
- It is a large gauge needle (typically 18 G).
- It has a curved blunt tip to help avoid dura puncture.
- Some needles have wings for user control.
- Graduations (1 cm) help users track the needle's depth.
Epidural Kit
- Various instruments needed for epidural procedures like syringes, needles, catheters, and sterile coverings are part of this kit.
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Description
This quiz covers various regional anesthetic techniques, including local infiltration, nerve blocks, and their applications. You'll learn about the methods of administering anesthesia and the specific drugs used, such as xylocaine and bupivacaine. Test your knowledge on the types of anesthetic techniques and their effectiveness.
