8 Anesthesia Flashcards by Ryan Bird

Concerning findings on airway exam for anesthesia?

BMI >31
Interincisor or intergingival distance >3cm
Class III or IV mallampati classification
Inability to protrude lower incisors to meet or extend past upper incisors
Radiation changes or thick obese neck
Limited extension or possible unstable cervical spine
Presence of full beard

How well did you know this?

Not at all

Perfectly

Mallampati classification of the airway

Class I - Can see everything
Class II - cannot see all of pillars or uvula
Class III - cannot see pillars
Class IV - Cannot see anything

How well did you know this?

Not at all

Perfectly

MAC

Minimum alveolar concentration - smallest conc of inhalation agent at which 50% of patients will not move with incision
Small MAC - more lipid soluble = more potent
Speed of induction is inversely proportion to solubility

How well did you know this?

Not at all

Perfectly

Common AE for inhaled anesthetics?

Unconsciousness, amnesia, analgesia
Blunt hypoxic drive
Myocardial depression, increase cerebral blood flow and decrease renal blood flow

How well did you know this?

Not at all

Perfectly

Nitrous oxide

Fast
Minimal myocardial depression
Tremors at induction

How well did you know this?

Not at all

Perfectly

Halothane

Slow onset/offset
Highest degree of cardiac depression and arrhythmias
Least pungent - good for children

How well did you know this?

Not at all

Perfectly

Halothane hepatitis

Fever
eosinophilia
Jaundice
Increased LFTs

How well did you know this?

Not at all

Perfectly

Sevoflurane

Fast
Less laryngospasm
Less pungent
Good for mask induction

How well did you know this?

Not at all

Perfectly

Isoflurane

Good fro neurosurgery - lowers brain consumption, no increase in ICP

How well did you know this?

Not at all

Perfectly

Enflurane

Can cause seizures

How well did you know this?

Not at all

Perfectly

Sodium thiopental

Barbiturate
Fast acting
AE: decreased cerebral blood flow and metabolic rate; decreased blood pressure

How well did you know this?

Not at all

Perfectly

Propofol

Very rapid distribution and on/off
Amnesia, sedative, NOT analgesic
AE: Hypotension, respiratory depression, egg allergy
Metabolized in liver and by plasma cholinesterases

How well did you know this?

Not at all

Perfectly

Ketamine

Dissociation of thalamic/limbic systems
Cataleptic state (amnesia, analgesia)
AE: Hallucinations, catecholamine release (increased CO2, tachycardia), increased airway secretions, increased cerebral blood flow
CI: head injury
Good for children

How well did you know this?

Not at all

Perfectly

Etomidate

Fewer hemodynamic changes
Fast acting
Continuous infusions can lead to adrenocortical suppression

How well did you know this?

Not at all

Perfectly

What is the last muscle to go down and first muscle to recovery from paralytics?

Diaphragm

How well did you know this?

Not at all

Perfectly

What is the first muscle to go down and last muscle to recover from paralytics?

Neck muscles and face

How well did you know this?

Not at all

Perfectly

Succinylcholine

Fast, short acting
AE: Fasciculations, increase ICP, malignant hyperthermia
CI: Hyperkalemia, open-angle glaucoma, atypical pseudocholinesterases

How well did you know this?

Not at all

Perfectly

Malignant hyperthermia

Defect in calcium metabolism
Calcium release from sarcoplasmic reticulum causes muscle excitation-contraction syndrome
AE: increase ETCO2, fever, tachycardia, rigidity, acidosis, hyperkalemia
Treatment: dantrolene, cooling blankelts, HOC3, glucose, supportive care

How well did you know this?

Not at all

Perfectly

What is the first sign of malignant hyperthermia?

Increased ETCO2

How well did you know this?

Not at all

Perfectly

Dantrolene - MOA, dose

Inhibits Ca release and decouples excitation complex

Dose 10mg/kg

How well did you know this?

Not at all

Perfectly

Hyperkalemia and succinylcholine

Depolarization release more K

CI: Severe burns, neurologic injury, neuromusclar disorders, spinal cord injury, massive trauma, acute renal failure

How well did you know this?

Not at all

Perfectly

Atypical pseudocholinesterases and succinylcholine

Causes prolong paralysis

Seen in Asians

How well did you know this?

Not at all

Perfectly

Non-depolarizing paralytic agents

Inhibit neuromuscular junctions by competing with acetylcholine
Get prolongation of these agents with myasthenia graves

How well did you know this?

Not at all

Perfectly

Cis-atracurium

Hoffman degradation
Can be used in liver and renal failure
Causes histamine release

How well did you know this?

Not at all

Perfectly

Rocuronium

Fast, intermediate duration | Hepatic metabolism

Pancuronium

Slow acting, long-lasting Renal metabolism AE: tachycardia

Neostigmine | Edrophonium

Blocks acetylcholinesterase, increasing acetylcholine

Reversing drugs for non-depolarizing agents

Neostigmine Edrophonium Atropine/glycopyrrolate - given with to counteract the effects of generalized acetylcholine overdose

MOA - local anesthetics

Works by increasing action potential, preventing Na influx

Why are infected tissues hard to anesthetize?

Acidosis inactivates it

AE of local anesthetics?

``` Tremors Seizures Tinnitus Arrhythmias (CNS symptoms present before cardiac) ```

Epinephrine with local anesthetics?

Allows higher doses to be used - vasoconstriction keeps the anesthetic local CI: arrhythmias, unstable angina, uncontrolled HTN, poor collaterals (penis, ear), uteroplacental insufficiency

AE of opioids

Profound analgesia Respiratory depression (decrease CO2 drive) No cardiac effects Blunt sympathetic response

Morphine

``` Analgesia Euphoria Respiratory depression Miosis Constipation Histamine release (hypotension) Decrease cough ```

Demerol

``` Analgesia Euphoria Respiratory depression Miosis Tremors Fasciulations Convulsions NO histamine release Can cause seizures - build up of normeperidine analogue (renal failure) ```

Methadone

Simulates morphine | Less euphoria

Fentynal

Fast acting 80x strength of morphine No histamine release

Sufentanil | Remifentanil

Fast-acting narcotics | Short half-life

Most potent narcotic?

Sufentanil

Effects of benzodiazepines

``` Anticonvulsant Amnesic Anxiolytic Respiratory depression NOT analgesia Liver metabolism ```

Versed

Midazolam Short acting CI: pregnancy (crosses placenta)

Valium

Diazapam | Intermediate acting

Ativan

Lorazepam | Long acting

Benzo overdose

Flumazenil Competitive inhibitor AE: seizures, arrythmia CI: elevated ICP, status epilepticus

AE of morphine in epidural

Respiratory depression

AE of lidocaine in epidural

Decreased heart rate and hypotension

Treatment of acute hypotension and bradycardia in patient with epidural?

Turn epidural down Fluids Phenylephirine, atropine

CI for epidural

Hypertrophic cardiomyoptahy Cyanotic heart disease (Sympathetic denervation causes decreased afterload, which worsens these conditions)

Spinal anesthesia

Injection into subarachnoid space - spread determined by baricity and patient position - Neurological blockade is above motor blockade CI: hypertrophic cardiomyopathy, cyanotic heart disease

Caudal block

Through sacrum | Good for pediatric hernias and perianal surgery

Epidural and spinal complications

``` Hypotension Headache Urinary retention (require catheter) Abscess/hematoma formation Respiratory depression (with high spinal) ```

Spinal headache

Caused by CSF leak after spinal/epidural Headache gets worse with sitting up Tx: rest, fluids, caffeine, analgesics; blood patch to site if it persists >24 hours

What pre-op conditions are associated with the most post-op hospital mortality?

Renal failure* | CHF

Symptoms of post-op MI

May have no pain or EKG changes | Sx: hypotension, arrhythmias, increased filling pressures, oliguria, bradycardia

What patients need pre-op work up?

``` Angina Previous MI SOB CHF Walk <2 blocks secondary to SOB or CP FEV1 <70% predicted Severe valvular disease PVCs >5/min High grade heart block Age <70 Dm Renal insufficiency Major vascular surgery ```

ASA class 1

Healthy

ASA class 2

Mild disease without limitations (controlled HTN, obesity, DM, sig smoking history, older age)

ASA class 3

Severe disease (angina, previous MI, poorly controlled HTN, DM with complications, mod COPD)

ASA class 4

Severe constant threat to life (unstable angina, CHF, renal failure, liver failure, severe COPD)

ASA class 5

Moribund (ruptured AAA, saddle PE)

ASA class 6

Donor

ASA class E

Emergency

Aortic, major vascular and peripheral vascular surgeries are ___ risk?

High

Carotid endarterectomy is ____ risk?

Moderate

Biggest risk factors for post-op MI?

``` Age >70yo DM Previous MI CHF Unstable angina ```

High cardiac risk Stratification for non-cardiac surgical procedures?

Cardiac risk >5% - Emergent operations (esp elderly) - Aortic, peripheral and other major vascular surgery (except CEA) - Long procedure with large fluid shifts

Intermediate cardiac risk Stratification for non-cardiac surgical procedures?

Cardiac risk <5% - CEA - Head and neck surgery - Intraperitoneal and intrathoracic surgery - Orthopedic surgery - Prostate surgery

Low cardiac risk Stratification for non-cardiac surgical procedures?

Cardiac risk <1% - Endoscopic procedures - Superficial procedures - Cataract surgery - Breast surgery

Best determinant of esophageal vs. tracheal intubation?

ETCO2

Intubated patient undergoing surgery with sudden transient rise in ETCO2

Most likely hypoventilation | Tx: increase TV or increase RR

Intubated patient with sudde drop in ETCO2?

MC: disconnected from the vent | PE - when associated with hypotension

MC PACU complication

Nausea and vomiting

High volume hospitals are associated with lower mortality for:

AAA repair | Pancreatic resection