describe goals of anesthesia
- MAINTAIN PHYSIOLOGIC HOMEOSTASIS
- Cardiovascular function
- respiratory function
- renal function
- neurologic function
–> amnesia = lack of memory of perioperative/intraoperative period
–> analgesia = pain cnotrol
–> neuromuscular blockade (allows patient to remain still during surgery)
describe the cardiac risk assessment for non-cardiac procedures
- detailed history of patient’s symtpms and clinical course
- exercise tolerance
- clinical predictors (angina, coronary heart disease)
- FUNCTIONAL COPACITIY
–> assessment of cardiac functional status
- of prognostic value (pts with good functional status have lower risk of cardiac complications
–> expressed in metabolic equivalents (METS)
describe metabolic equivalents (METs)
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- indicator of functional status include the following
–> can take care of self, such as eat, dress, or use the toilent (1 MET)
–> can walk up a flgiht of steps or a hill (4 METs)
- inability to climb 2 flights of stairs or walk 4 blocks is one important indicator of poor functional status and an increased risk of postoperative cardiopulmonary complications after major non-cardiac surgery
–> can do heavy work around the house such as scrubbing floors or lifting or moving heavey furniture (between 4 and 1- mets
_** 4 IS THE MAGIC NUMBER**!!!!!!!!!!!_
what are major predictors
- Recent MI or severe angina
- decompensated heart failure or significant valvular heart disease
- significant arrhythmias (defined as high-grade A-V block, sustained ventricular tachycarda, etc)
- Recent PCI (percutaneous coronary intervention)
what are some minor predictors
- advanced age
- abnormal ECG (left bundle branch block, ST-T wave)
- rhythm other than sinus
- uncontrolled systolic hypertension
describe preoperative evaluation of the patient with respiratory disease
- Preexisting pulmonary disease (asthma, COPD)
- thoracic or upper abdominal surgery
- smoking
- obesity
- age > 60 years
- prolonged general anesthesia
AMERICAN SOCIETY OF ANESTHESIOLOGIST (ASA) physical status classification
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- Class I = normal helathy patient
- Class II = mile systemic disease (on one medication), smoker
- Class III = severe systemic disease, but not incapacitation (htn on more than one medication), diabetic with some end organd damage
- Class IV = severe systemic disease that is constant threat to life (unstable angina, oxygen-dependent COPD)
- Class V = moribund, not expected to live 24 hours regardless of operation
- Class IV = organ donor with brain death
define general anesthesia
- altered physiologic state characterized by reversible loss of consciousness, analgesia of the entire body, amnesia, and some degree of muscle relaxation
- divided into three distinct phases: induction, maintenance, and emergence
–> Induction = propofol (most common due to recovery profile), etomidate, ketamine
–> maintenance = volatile anesthetics sevoflurane and desflurane (low hepatotoxicity)
–> Emergence = pts is restored to a state of consciousness
describe femoral nerve block
- the patient is placed in a supine position.
- the common femoral artery is palpated
- the needle is inserted just below the inguinal ligament and 1.5 cm lateral to the artery
define popliteal block
- anesthetizes the sciatic nerve in the popliteal fossa prior to its division into the tibial and the common fibular nerves
ankle blocks
- anesthetizes four branches of the sciatic nerve
spinal anesthesia
- small gauge needle is inserted into lumbar interspace until is reaches SUBARACHNOID SPACE
- local anesthetic is then injected to produce TEMPORARY numbness andmuscle relaxation
describe epidural anesthesia
- acheived with the placement of small guage flexible catheter into the epidural space via a needle
- REPEAT DOSING of local anesthetic and adjunctie medication for prolonged intraoperative management is possible by leaving a catheter in the central neuraxial space for infusion
describe monitored anesthesia
- includes intraoperative physiologic monitoring, provision of analgesia and anxiolysis, and further intervention and support as necessary
- does not involve complete loss of consciousness
–> supplemented with lcoal anesthetic block
–> patient will feel pressure at the oeprative site but should not feel pain
describe concious sedation
- No anesthesia personnel in attendance - sedative and/or anesthesia is administered by surgeon and patient is communicative and conscious (often used in ER setting for reduction of fractures)
