Mod IV: Regional Anesthesia Part 1 Flashcards
Regional Anesthesia
The first local anesthetic
Cocaine
Spanish Jesuit, Father Burnabe Cobo
1653 Wrote about chewing the leaves of the coca plant to relieve a toothache
Regional Anesthesia
Sigmund Freud (1883-1887) wrote many articles detailing the virtues of cocaine:
Stimulant
Analgesic
Addiction treatment?
It has been argued that much of his early works on psychoanalysis were influenced by his cocaine use
Regional Anesthesia
Karl Kollar, college and friend of Freud, in 1884 demonstrated the local anesthetic properties of cocaine allowing him to perform
“painless” surgery on the eye
This is the first documented application of a drug to produce localized anesthesia
Regional Anesthesia
William Halsted & Alfred Hall, only 8 weeks after Kollar’s announcement they began experimenting with injecting nerves with cocaine, in December 1884 published injecting cocaine SQ into forearm and were able to produce:
Analgesia
Injected directly into Ulnar N. and produced complete anesthesia to its distal distribution
Regional Anesthesia
William Halsted & Alfred Hall, only 8 weeks after Kollar’s announcement they began experimenting with injecting nerves with cocaine, in December 1884 published injecting cocaine directly into Ulnar N. and produced:
Complete anesthesia to its distal distribution
Regional Anesthesia
Brachial plexus blocks were performed by Halsted using a cut-down technique and injecting cocaine directly into:
each nerve root
Regional Anesthesia
1st Percutaneous Blockade performed by G. Hirschel in 1911 was:
Axillary brachial plexus block
Regional Anesthesia
Selective anesthesia and analgesia that is achieved by exposing selected nerves to LA is also known as:
Regional Anesthesia
Regional Anesthesia
Which discipline tells us where nerves travel and what they do?
Applied Anatomy
Regional Anesthesia
We can choose how dense and how long the block will last by using which scientific discipline?
Applied Pharmacology
Regional Anesthesia
What are the different types of Regional Anesthesia?
Topical
Local infiltration
Field Block
Intravenous Regional – Bier block
Peripheral nerve block
Neuraxial
Regional Anesthesia
What are the possible uses of topical anesthesia?
IV placement
Eye procedures
ENT procedures
Awake fiber optic intubations
Dental pain
Surgical wound closure
Acute/chronic pain management
Regional Anesthesia
Which agents are used for topical anesthesia?
EMLA cream/patch
Eutectic Mixture of Local Anesthetics
Mixture of 2.5%Lidocaine and 2.5%Prilocaine
Cocaine, Tetracaine, Proparacaine (Alcaine)
Benzocaine spray
Methhemaglobinemia
Lidocaine jelly/ointment
Skin refrigerant spray
Regional Anesthesia
What the composition of EMLA cream/patch?
Eutectic Mixture of Local Anesthetics
Mixture of 2.5%Lidocaine and 2.5%Prilocaine
Regional Anesthesia
Possible complication a/w the use of Benzocaine spray
Methhemaglobinemia
Regional Anesthesia
What are advantages of Topical anesthesia?
Extremely Easy
Low skill
Low risk
Great for mucous membranes
Regional Anesthesia
What are disadvantages of Topical anesthesia?
Short duration 1-4 hours
Slow onset over skin (Needs soak time!!!)
Doesn’t work well or at all on inflamed or infected tissues
Regional Anesthesia
Type of regional anesthesia where a LA is injected directly into a tissue:
Local infiltration
Regional Anesthesia - Local Infiltration
What the uses for Local Infiltration?
Traumatic Wound closure
Laceration closure in ER
Surgical Wound closure
Injected as wound is closed
Pre-emptive analgesia
Trocar sites - Joint injection
Regional Anesthesia - Local Infiltration
Advantages
Fast and Easy
Low skill
Lower risk
Regional Anesthesia - Local Infiltration
Disadvantages
Short duration 1-6 hours
Doesn’t work well or at all on inflamed or infected tissues
Requires provider to place injections systematically to ensure good coverage
Patchy coverage can be commonplace
Regional Anesthesia
Infiltration of LA around an area you wish to anesthetize:
Field blocks
Regional Anesthesia - Field blocks
Uses:
Carotid endarterectomy
Superficial cervical plexus
I&D of wounds
Intercostobrachial and medial brachial cutaneous nerves
Dentistry
Plastic surgery
Regional Anesthesia - Field blocks
Advantages:
Fast and Easy to perform
Low risk procedure
Multiple LA options
Can be used to supplement patchy peripheral or neuraxial blocks
Regional Anesthesia - Field blocks
Disadvantages:
Inconsistent coverage
Only covers superficial structures
Relatively short duration of action
Regional Anesthesia
Injection of LA into the venous system of an exsanguinated extremity to produce surgical anesthesia for short procedure:
IV Regional Anesthesia or Bier Block
IV Regional Anesthesia or Bier Block
Uses:
Best suited for short soft tissue upper extremity procedures
Can be used for lower extremity
IV Regional Anesthesia or Bier Block
Advantages:
Relatively easy to perform
Provides surgical anesthesia quickly
IV Regional Anesthesia or Bier Block
Disadvantages:
Tourniquet pain limits useful duration
Tourniquet must be inflated for at least 20 minutes
Must be able to obtain IV access on operative limb
Pt habitus must be suitable for proper tourniquet fit
IV Regional Anesthesia or Bier Block
Pt habitus must be suitable for proper tourniquet fit. Failed tourniquets risk:
Acute LA Toxicity
Large volume LA immediately entering central circulation
Bier Block - Procedure
IV Heplock established; where?
Hand preferably
Bier Block - Procedure
Double Pneumatic tourniquet to upper arm. What should you do with the arm prior to protect it?
Pad with cotton
Bier Block - Procedure
How do Exsanguinate Arm/leg prior to Bier block?
Raise arm/leg up
Apply Esmarch bandage in a spiral from hand/leg to proximal cuff of tourniquet
Bier Block - Procedure
Tourniquet pressure to:
50-100mmHg above SBP
Bier Block - Procedure
Tourniquet cuff Sequence:
1 – Inflate Distal cuff
2 – Inflate Proximal cuff
3 – Deflate Distal cuff
Bier Block - Procedure
Injection of LA:
30-50ml 0.5% Lidocaine
3mg/kg MAX
Use NO OTHER LA!!
Bier Block - Procedure
When should you remove Heplock?
After you have injected LA
Bier Block - Procedure
After injection of LA, how long till onset?
< 5 minutes
Bier Block - Procedure
What should you do when tourniquet pain starts?
Inflate distal cuff, then
Deflate proximal
Bier Block - Procedure
From injection, never deflate cuff less than
20 minutes
Bier Block - Procedure
When would you use Two stage tourniquet deflation?
For short procedures (<30-45minutes)
Bier Block - Procedure
What happens during Two stage tourniquet deflation?
Deflate for 10 seconds
Inflate for 1 minute
Bier Block - Procedure
What’s the result of Two stage tourniquet deflation?
more gradual LA washout
Regional anesthesia
When is Peripheral Nerve Block indicated?
Surgical anesthesia
Post-op pain control
Vascular dilation
Chronic pain
Regional Anesthesia - Peripheral Nerve Block
What are some applications Peripheral Nerve Blockade?
Podiatry
Hammer toe, bunion, etc
Hand and wrist
Trigger finger, carpal tunnel
Hernia
Inguinal hernia repair
Chronic pain
Trigeminal
Airway blocks
Eye blocks
etc.
Regional Anesthesia - Peripheral Nerve Block
Advantages:
Specific control of what is being blocked
And possibly more import what is not blocked
Requires working knowledge of fine anatomic detail
Can avoid systemic side effects of neuraxial techniques
Continuous Perineural catheters can be used
Regional Anesthesia - Peripheral Nerve Block
Disadvantages:
Anatomical variability and technical difficulty can lead to failure
Especially in landmark techniques
Inadvertent blockade of nerves due to proximity
Phrenic nerve block
Regional Anesthesia - Peripheral Nerve Block
Which nerve should you be concerned about inadvertently blocking with a Peripheral Nerve Blockade approach?
Phrenic nerve
“C3, C4, C5 Keep the diaphragm alive”
Regional Anesthesia
Neuraxial approaches include:
Epidural, Spinal, Caudal
Regional Anesthesia - Neuraxial
Indicated for pain control when?
Surgical and Post-op pain control
Regional Anesthesia - Neuraxial
Uses:
OB
Hip and lower extremity
Multiple Thoracic, Abdominal, and pelvic surgeries
Esophagectomy
Lobectomy
Prostate
etc
Regional Anesthesia - Neuraxial
Advantages:
Provide coverage to large sections of the body
Catheter placement allows for analgesic control
Regional Anesthesia - Neuraxial
Disadvantages:
Can be technically difficult
Sympathectomy
Contraindicated for many comorbidities and pt specific factors
Regional Anesthesia - Neuraxial
Contraindicated for many comorbidities and pt specific factors, including:
Coagulopathy/anticoagulation
Uncooperative pt
Stenotic heart valve lesions
etc.
