Podcast
Questions and Answers
Which of the following is NOT a reason for using regional anesthesia?
Which of the following is NOT a reason for using regional anesthesia?
For what kinds of surgeries is spinal anesthesia ideal?
For what kinds of surgeries is spinal anesthesia ideal?
What is the typical location for inserting a spinal needle?
What is the typical location for inserting a spinal needle?
What type of anesthetic is administered during a spinal procedure?
What type of anesthetic is administered during a spinal procedure?
Signup and view all the answers
Which of the following is a contraindication for regional anesthesia?
Which of the following is a contraindication for regional anesthesia?
Signup and view all the answers
Which of these factors can affect the distribution of spinal anesthesia?
Which of these factors can affect the distribution of spinal anesthesia?
Signup and view all the answers
What is the most effective way to treat hypotension caused by spinal anesthesia?
What is the most effective way to treat hypotension caused by spinal anesthesia?
Signup and view all the answers
Which of the following is NOT a common immediate complication of spinal anesthesia?
Which of the following is NOT a common immediate complication of spinal anesthesia?
Signup and view all the answers
Which of the following is a recommended treatment for post dural puncture headache (PDPH)?
Which of the following is a recommended treatment for post dural puncture headache (PDPH)?
Signup and view all the answers
What does the anesthetic do to the body during spinal anesthesia?
What does the anesthetic do to the body during spinal anesthesia?
Signup and view all the answers
Flashcards
Spinal Anesthesia
Spinal Anesthesia
A medical procedure that numbs the body below the injection site generally done without a catheter.
Factors Affecting Distribution
Factors Affecting Distribution
Elements that influence the effectiveness of spinal anesthesia, including injection site and shape of the spinal column.
Cardiovascular Effects
Cardiovascular Effects
Effects of spinal anesthesia on the heart, mainly venodilation affecting blood flow and pressure.
Spinal Headache
Spinal Headache
Signup and view all the flashcards
PDPH Treatment Options
PDPH Treatment Options
Signup and view all the flashcards
Regional Anesthesia
Regional Anesthesia
Signup and view all the flashcards
Indications for Regional Anesthesia
Indications for Regional Anesthesia
Signup and view all the flashcards
Contraindications for Regional Anesthesia
Contraindications for Regional Anesthesia
Signup and view all the flashcards
Preparation for Regional Anesthesia
Preparation for Regional Anesthesia
Signup and view all the flashcards
Study Notes
Regional Anesthesia
- Regional anesthesia uses local anesthetics to block pain signals from a specific area of the body (e.g., arm, leg, abdomen).
- Indications for regional anesthesia include avoiding general anesthesia (e.g., difficult intubation), providing high-quality postoperative pain relief, and facilitating early return to function.
- Uncooperative or restless patients and some psychiatric patients are contraindicated for regional anesthesia.
Preparation Before Local Anesthetic Injection
- Intravenous cannula is necessary.
- A tilting table or trolley is used for patient positioning.
- Facilities for intermittent positive pressure ventilation (IPPV) with oxygen are required.
- Patient monitoring (ECG, non-invasive blood pressure, pulse oximetry, end-tidal carbon dioxide) is essential.
- Suction equipment and catheters should be readily available.
- Syringes and ampoules of tranquilizers (e.g., midazolam), induction agents (e.g., propofol), muscle relaxants (e.g., suxamethonium), atropine, and pressor agents (e.g., ephedrine) are crucial.
- Solutions for infusion (crystalloid and colloid solutions) are needed.
- Full resuscitation equipment and drugs (including a defibrillator) are important.
Spinal Anesthesia (Intradural)
- Anatomy: The spinal cord ends at the level of L1 in adults and L3 in children.
- Indications: Ideal for surgeries of lower limbs, perineum, pelvis, abdomen, Renal failure, cardiac disease, liver disease, obstetric anesthesia, full stomach, and upper airway distortions.
- Levels of block: sympathetic paralysis, sensory block, and motor nerve blockade.
- Technique: Small needle injected directly into cerebrospinal fluid between the third and fourth lumbar vertebrae.
- Effects: Numbs the body below the injection site; sometimes above as well, temporarily impairing leg movement until the anesthetic wears off.
Epidural Anesthesia (Extradural)
- Anatomy: Potential space between the dura mater and ligament flavum, containing vasculature, nerves, fat, and lymphatic fluids.
- Level: varies depending on location—widest at L2 (5-6 mm) and narrowest at C5 (1-1.5 mm).
- Volume: 118 mL for average adult. Obese adults may have wider pockets of the epidural space.
- Technique: Hollow needle and catheter inserted into the space between the spinal column and outer membrane of the spinal cord; local anesthetic injected.
- Effects: Creates analgesia by blocking conduction at spinal nerve roots.
Complications
- Immediate: hypotension, bradycardia/cardiac arrest, high/total spinal block leading to respiratory arrest, urinary retention, epidural hematomas, bleeding.
- Late: Post-dural puncture headache (PDPH), backache, nausea, focal neurological deficit, bacterial meningitis, and sixth cranial nerve palsy.
- Spinal headache: More common in women ages 13-40. Treatment includes bed rest, fluids (intravenous or oral), simple analgesics (e.g., paracetamol, aspirin, or codeine). Occasionally, a blood patch is needed.
Factors Affecting Distribution
- Site of injection
- Shape of spinal column
- Patient height
- Angulation of needle
- Volume of CSF
- Characteristics of local anesthetic (density, specific gravity, dose, and volume)
- Patient's position (during and after the procedure)
Cardiovascular Effects (of local anesthetic)
- Predominant action is venodilation and reduction of: venous return, stroke volume, cardiac output, and blood pressure.
- Hypotension: treatment often involves increasing cardiac preload (ex: rapid infusion of intravenous fluid )
Types of Peripheral Nerve Blocks (Bier's Block)
- Intravenous regional technique for the extremities (e.g., below the elbow or knee).
- Useful for short surgical procedures (under 40–60 mins); tourniquet pain usually develops after this period.
- Exsanguination of the extremity is necessary to remove blood. A pneumatic tourniquet is inflated above the patient's systolic blood pressure.
- Anesthetic injections into the affected limb, while the limb is compressed with the tourniquet, allows the anesthetic to diffuse to surrounding tissues.
- Lidocaine (or prilocaine, avoiding bupivacaine) is most common agent used in Bier's blocks
- Use of bupivacaine is NOT RECOMMENDED given its cardiotoxicity.
Ultrasound-Guided Regional Anesthesia (USGRA)
- Ultrasound technology is used to guide needles for peripheral nerve blockade, to improve accuracy and reduce complications.
- PNB (peripheral nerve block) techniques have been demonstrated and used across numerous procedures in different locations and in upper or lower limbs, -US facilitates precise applications and demonstrates the sonoanatomy of affected nerves (ex: Brachial plexus).
Transversus Abdominis Plane (TAP) Block
- A local anesthetic injection that provides analgesia (pain relief) to the anterior and lateral abdominal wall.
- Targeting the anatomical plane between the transversus abdominis and internal oblique muscles to block related nerves (often thoracic and upper lumbar spinal levels). Used in surgeries affecting the abdomen.
Local Anesthetics
- Lidocaine, bupivacaine, levobupivacaine, and ropivacaine are examples.
- Dosage depends on factors such as age, body size, type of surgery, and duration of the procedure
- Dosage requirements are given in milliliters of solution (specific concentration). Spinal blocks are usually lower volume.
Comparison of Spinal and Epidural Anesthesia
- Spinal: Drug delivered into the subarachnoid space (CSF), injected below the 3rd lumbar vertebra, smaller dose (0.5-2ml), quicker onset (2-5mins), duration of effect 20 minutes
- Epidural: Drug delivered outside the dura mater (outside CSF), given at cervical, thoracic, lumber or sacral sites, larger dose, slower onset (5-15 mins), duration of effect 30-45 minutes
Contraindications to Central Neuraxial Blockade (spinal or epidural)
- Absolute: Raised intracranial pressure, coagulopathy/full anticoagulation therapy, and skin sepsis.
- Relative: Mildly impaired coagulation (platelets <80000/µL), should be weighed against the benefits of avoiding general anesthesia.
- Precautions: hypovolaemia, patient refusal, marked spinal deformity
Caudal Block
- Local anesthetic injection into the epidural space via the sacral hiatus to block sacral and coccygeal nerve roots.
- Ideal for superficial procedures on the lower body. (ex: skin grafting, perineal procedures, lower limb surgery)
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the essentials of regional anesthesia, including its uses, indications, and contraindications. This quiz also covers the critical preparations required before administering local anesthetic injections, ensuring patient safety and effective management.
