Anesthesia

Question 1

What is the Mallampati class in this image? https://images.cram.com/images/upload-flashcard/47/88/15/33478815_m.jpg

Answer 1

2

Question 2

Name two inhalation anesthetics and one depolarizing muscle relaxant which trigger MH

Answer 2

– All the inhalation anesthetics can cause MH: desflurane, sevoflurane, isoflurane, methoxyflurane halothane, enflurane\n\n\n– Depolarizing muscle relaxant: succinylcholine

Question 3

Indications for a difficult intubation

Answer 3

– Mallampati of 3 or 4\n– Mento–hyoid distance of less than 3 finger breadths\n– Reduced degree of head extension (<90 degrees)\n– Reduced jaw protrusion

Question 4

What are the predictors of poor bag mask ventilation

Answer 4

Beard\nObese (>26)\nNo teeth\nElderly (>55)\nSnores

Question 5

Why does CPAP use before surgery improve outcomes

Answer 5

Consistent use of CPAP, before and after surgery, as well as in hospital, reduces the risk of peri–operative complications.

Question 6

Choosing Wisely:\nDon’t order these 2 types of tests for asymptomatic patients undergoing low–risk non–cardiac surgery.

Answer 6

Lab tests\nElectrocardiograms

Question 7

Choosing Wisely:\nDon’t order these 2 types of tests for asymptomatic patients undergoing low–risk to intermediate risk non–cardiac surgery .

Answer 7

Echocardiogram\nCardiac stress testing

Question 8

Choosing Wisely: \n\nDon’t order a baseline chest X–ray in asymptomatic patients, except as part of ______ or __________evaluation.

Answer 8

Don’t order a baseline chest X–ray in asymptomatic patients, except as part of surgical or oncological evaluation.

Question 9

Describe the ASA Physical Status Classification System (1 to 5)

Answer 9

1. Healthy\n2. Mild systemic disease (smoker, well controlled DM)\n3. Severe systemic disease that is not incapacitating (non recent hx of MI, poorly controlled HTN)\n4. Incapacitating disease that is a threat to life (morbid obesity, ESRD without dialyses, recent MI)\n5. Moribund, not expected to survive more than 24 hours

Question 10

Why is spinal anesthetic contraindicated in aortic stenosis?

Answer 10

Post spinal hypotension

Question 11

What are the two life events promoting smoking cessation.

Answer 11

Pregnancy and Surgery\n\n\n (Smokers experience bronchospasm, increased secretions which increase pneumonia risk, lower oxygen delivery to surgical site increases infection risk)

Question 12

What are the As of Anesthesia

Answer 12

Awareness (unconscious)\nAmnesia\nAnalgesia (remove subconscious pain)\nAkinesia \nAnxiolysis

Question 13

Stages of Anaesthesia

Answer 13

Preparation\nInduction\nMaintenance\nEmergence \nRecovery

Question 14

When is rapid sequence induction (RSI) used?

Answer 14

When the patient is at increased risk for aspiration (e.g. decreased integrity of lower esophageal sphincter)\nUsed in emergencies, but only because the person has not been NPO

Question 15

What are the components of a rapid sequence induction?

Answer 15

Ready the suction apparatus\nPre–oxygenate the patient (no bag masking)\nInduction with pre–calculated induction agent\nIntubating dose of depolarizing muscle relaxant (succinylcholine or high dose rocuronium). \nAssistant applies cricoid pressure (Sellick’s maneuver) \n\nIntubation of trachea, cuff inflation and verification of proper tube position.

Question 16

What is the purpose of the Sellick Maneuver?

Answer 16

Occludes the esophagus to reduce the risk of passive aspiration

Question 17

Where is the cricoid cartilage, find it on yourself

Answer 17

https://images.cram.com/images/upload-flashcard/53/52/92/33535292_m.jpg

Question 18

Why shouldn’t people take diuretics and ACE inhibitors the day of surgery

Answer 18

Their NPO status is already putting them at an increased risk of hypovolemia and hemodynamic instability, no need for an additional diuretics and anti–hypertensives.

Question 19

IV induction agents

Answer 19

propofol, ketamine,thiopental or etomidate, (followed by non depolarizing muscle relaxant)

Question 20

What are some reasons to avoid using Succinylcholine in a patient?

Answer 20

Patients with hyperkalemia and renal failure\nPatients with history/ family history of malignant hyperthermia\nPatients with pseudocholinesterase deficiency(this is not an exhaustive list)

Question 21

Drug classes used in the maintenance phase

Answer 21

Inhaled agents, opioids, vasoactive medications, and non–depolarizing muscle relaxants (NDMR)

Question 22

What inhaled drugs are used for anesthesia maintenance?

Answer 22

Volatile agents (desflurane, isoflurane, sevoflurane)\nNitrous oxide

Question 23

What is the Minimum Alveolar Concentration?

Answer 23

MAC refers to the concentration of the inhaled agent in alveolar gas necessary to prevent movement of 50% of patients when a standard incision is made

Question 24

Which factors are associated with a lower MAC in a patient?

Answer 24

Advanced age, pregnancy, hypothermia, alcohol intoxication, depressant drugs (muscle relaxants, opioids, benzos, central antihypertensives)

Question 25

Risk associated with volatile agents

Answer 25

Trigger malignant hyperthermia

Question 26

Risks associated wtih Nitrous oxide (N2O)

Answer 26

Expands volume of gas containing spaces because it diffuses so easily across membranes. \nAs a result, increases size of pneumothorax, emphysematous bleb, distended bowel loop.

Question 27

Which inhaled agent is best for an extended surgery in an obese patient.

Answer 27

Desflurane is a better choice, it is less fat soluble so has a faster onset and offset.\nOn the other hand, sevoflurane is fat soluble, and is absorbed over the extent of a long surgery.

Question 28

What benefit does sevoflurane have in the context of COPD?

Answer 28

Bronchodilating effect and less irritating to airway.

Question 29

Why are opioids given in the maintenance phase?

Answer 29

Provide analgesia, and to reduce the requirement of other maintenance agents.

Question 30

What opioids are used intraoperatively?

Answer 30

fentanyl, sufentanil, remifentanil and alfentanil because they are short acting, giving the anesthesiologist more control.

Question 31

What is the max N2O you can give

Answer 31

70% (leave 30% for O2)

Question 32

When are opioids generally admistered?

Answer 32

As a loading dose before induction. Helps blunt response to intubation and provides baseline plasma level for anaesthetic throughout the surgery.

Question 33

What anticholinesterase is most frequently used to reverse neuromuscular blockade?

Answer 33

neostigmine – acts by inhibiting acetycholinesterase enzymes, and thereby increasing the amount of acetylcholine in the neuromuscular junction

Question 34

How does a neuromuscular junction work?

Answer 34

stimulation causes ACh to be released from presynaptic neuron —>diffuses and binds to AChR on post–synaptic motor end plate —> Ca release—> muscle excitation + contraction. \n\n ACh released from AChR —> degraded by ACh–esterase enzyme.

Question 35

How does a neuromuscular blockade work with Rocoronium? Succinylcholine?

Answer 35

Rocuronium\nRocuronium binds to receptor so acetylcholine cannot bind. It is non depolarizing, so it does not trigger the release of calcium and the resulting muscle contraction.\nSuccinylcholine\nAlso binds to acetycholine receptor. However, it is depolarizing, meaning that it actually triggers a muscle contraction. However, after that contraction ends no additional contraction is possible because succinylcholine cannot be degraded by ACh–esterase enzyme

Question 36

How does a neuromuscular blockade reversal work?

Answer 36

Acetylcholinesterase breaks down acetylcholine. Acetylcholinesterase inhibitors (e.g., neostigmine) prevent this breakdown, increasing acetylcholine levels. The additional acetylcholine out competes the Rocuronium.

Question 37

Benefit of sugammadex

Answer 37

Removes rocoronium from acetylcholine receptor (exact mechanism unknown) . Works when neostigmine won't.

Question 38

What is the "Train of Four"

Answer 38

Device delivers four electrical stimuli to muscle.\nMuscle response as measured by machine suggests the degree to which acetylcholine receptors have been blocked \nFull blockade (less than two twitch responses) suggests neostigmine cannot yet help acetycholine to out compete rocuronium

Question 39

Side effects of neostigmine

Answer 39

Parasympathetic response: bradycardia and SLUDD – salivation, lacrimation, urination, defecation, digestion\nNB: excess salivation can present an aspiration risk

Question 40

Four Drugs for Post Operative Nausea and Vomiting

Answer 40

Metoclopramide\nOndansetron\nDexamethasone\nGravol

Question 41

What are the stages of post op pain management? Why is pain management important?

Answer 41

Walk down the WHO analgesia ladder, starting with intense analgesia to prevent chronic pain syndromes and avoid the negative hemodynamic effects of pain.