Anesthesia Flashcards
Types of Anesthesia
General
Sedation
Regional
Define General Anesthesia
Suppression of activity in the CNS
Unconsciousness & total lack of sensation
Define Sedations
Inhibition of transmission of nerve impulses between higher & lower centers of the brain
Inhibition of anxiety & memory
Define Regional Anesthesia
Use of local anesthetics to make a portion of the body insensate by blocking transmission of nerve impulses between a part of the body & the spinal cord
Peripheral Anesthesia
Inhibits sensory perception within a specific location
Nerve blocks
Central Anesthesia
Local anesthetic delivered around the spinal cord & removes sensation of the body below the level of the block
Risks of Anesthesia
Death
MI
PE
Post op N/V
ASA 1
Normal healthy patient
ASA II
Patient with mild systemic disease
Smoking, pregnancy, obesity, well controlled DM or HTN, lung disease
ASA III
Patient with sever systemic disease, not incapacitating
DM, poorly controlled HTN, hx of MI, CVA, TIA, cardiac stent; COPD, ESRD, hepatitis, pacemaker, EF less than 40%, congenital metabolic abnormalities
ASA IV
Patient with severe systemic disease that is a constant threat to life
Recent MI, CVA, TIA, cardiac stent; ongoing cardiac ischemia or severe valve dysfunction; ICD; EF below 25%
ASA V
Moribund patient who is not expected to survive
Ruptured AAA; intracranial bleed; ischemic bowel with significant cardiac path
ASA VI
Delivered brain-dead
Organ donor for transplantation
Regional/Local Anesthesia
Pain blocked from a part of the body using local anesthetics
Types of Regional Anesthesia
Infiltrative Peripheral nerve block IV regional anesthesia Central nerve blockage Topical anesthesia Tumescent anesthesia
Infiltrative Regional Anesthesia
Local anesthetic injected in a small area to stop sensation
Peripheral Nerve Block
Local anesthetic injected near a nerve that provides sensation to a portion of the body
IV Regional Anesthesia
Dilute local anesthetic infused to a limb through a vein with a tourniquet placed to prevent the drug from diffusing out of the limb
Central Nerve Blockage
Infusion or injection of local anesthetic in or around a portion of the CNS
Spinal or epidural
Topical Anesthesia
Special formulation that diffuses through the skin or mucous membranes
Tumescent Anesthesia
Large amount of dilute local anesthesia infiltrated into the subcutaneous tissue used in liposuction
Indications for Neuroaxial Anesthesia
Surgery or pain
Appropriate distribution
Contraindications to Neuroaxial Anesthesia
Patient refusal
Infection
Coagulopathy
Benefits of Spinal Anesthesia
Decreased surgical time
Less blood loss
Less intraoperative transfusion requirements
Decrease the incidence of DVT or PE
Benefits of Epidural Anesthesia & Analgesia
Less blood loss
Reduced platelet aggregation
Reduced stress response to surgery
Decreased incidence of DVT
Improved graft potency after LE revascularization
Patients with general & epidural for aortic surgery had lower incidence of death & major complications
Complications of Spinal/Epidural
Post procedural headahce
Spinal hematoma or abscess
Drug Concentration (%) of Local Anesthetics
% x 10=mg/mL
Epinephrine (g/mL)
1:200,000
5 ug/mL
Why add epinephrine to local anesthetics?
Prolong surgical anesthesia time
Decrease peak serum levels
Intravascular marker
Decrease surgical site bleeding
When to not add epinephrine to lidocaine?
Fingers/toes
Penis
Ear/nose
Skin flaps
Scale of Local Anesthetic Toxicity
Dizziness Tinnitus Nystagmus, dysphoria, shivering Somnolence, muscle twitching Seizures Cardiac arrhythmias Cardiovascular instability & collapse
Treatment of Local Anesthetic Toxicity
Stop injection Call for help Supportive care 20% intralipid 1.5 mL/kg IV bolus (may repeat 1-2 times) Cardiopulmonary bypass
