local and regional aneasthesia Flashcards
definition of local anaesthesia
infiltration of a local anesthetic agent at the surgical site
definition of regional anesthesia
blockade of the nerve supply to a surgical site rendering it insensate using local anesthetics via numerous methods
advantages of local and regional anesthesia
- complications and adverse reactions are less frequent and less severe than general
- non explosive
- consciousness allows the patient to cooperate therefore => easy to apply and implement
- economical (cheaper)
*
Disadvantages of local and regional anesthesia
no muscle relaxation acheived unlike general
can’t be used in some surgical interventions e.gintradermal, skin transplants
contraindications of local and regional anesthesia
coagulopathy, shock, sepsis, raised ICP
which LA has the strongest surface anesthetic action on the mucous membranes
Cocaine- highly toxic - (therefore applied only to mucous membranes)
additonal properties include
- local vasoconstrictor
- dilates the pupils - eye practice
which LA has the least toxicity
Procaine (Novocaine)
disadvantantages
- short-term effect with poor penetration ability
- local vasodilator effect worsening/causing weak effect
- lack of superficial anesthetic action on the mucous membranes (opposite of cocaine)
Which LA is a better version of novocaine with a very wide application including antiarrythmic action
Lidocaine
advantages over novocaine
- faster acting and longer-lasting action
- better tissue permeability
- good anesthetic effect on mucous membranes
- good antiarrhythmic action
- weak local vasodilatory effect
- less toxicity
which LA is
used in longer interventions as it’s more potent and longer-lasting action than Lidocaine
provides some postoperative analgesia
Bupivacaine (Marcaine)
pro’s
no local vasodilator action
more potent, longer acting
post op analgesia
con
more toxic than lidocaine (more potent duh)
when is local and regional anesthesia indicated
superficial and non invasive surgical, diagnostic and therapeutic interventions
dental anaesthesia
Outpatient procedures
in cases where General Anesthesia is CI
when the pt is calm and ready to cooperate
is allergy to a LA a complete or relative CI
C O M P L E T E
other C.I
- mentally ill pts ( not calm and can’t coop)
- pt’s in very serious critical condition
complications/ ADR’s of LA
- Hypersensitivity
-
Local anesthetic toxicity - when injected into a blood vessel
- periooral numbness, metallic taste, dizziness,
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Local Anesthetic Systemic Toxicity- progression of LAT inittially mild then severe
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Nerological manifestations
- mild: confusion, LAT sx
- severe: 1) CNS excitation: seizures, agitation=> 2)CNS depression: bradypnea & bradicardia , coma
- cardiovascular
- initial hypertensive and tachycardic excitatory phase wiith ventricular arrhythmias,
- subsequent cardiac depression with bradycardia, myocardial depression, conduction block, asystole and cardiac arrest
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Nerological manifestations
list some examples of regional anesthesia
- stem
- spinal
- epidural
- sacral epidural
- peripheral nerve block
define STEM regional anesthesia
anesthetic injected into nerve trunk innervationg entire course from the brain to the terminal branches
which RA involves blockade of the spinal cord and cauda equina by injection of LA into the intrathecal space usually at or below. L2 level, with 1% lidocaine
spinal anesthesia
- L2: only the filum terminale is located and there is no danger of injuring the spinal cord.
- blocks the sensory, motor and autonomic fibers all 3
- commonly used *1% lidocaine solution*
- performed in a sitting or lateral position.
- shaking of the feet after about 3 minutes shows effect
- complete anesthesia occurs after 10-15 minutes.
- The height of the blockade is determined by area requiring req
- high spinal block (T6 to S5) the puncture is made at L3
- middle spinal block (T10 to S5), the puncture at L4-L5.
- Low spinal block - S2 - S5.
RA where a catheter is placed into the epidural space at any point along the spinal column
Epidural block
