Lecture 2

Question 1

List The “A” components of operative anesthesia

Answer 1

Anesthesia – no feeling
Analgesia – no pain
Akinesia – no movement
Areflexia – blunting of autonomic reflexes
Anxiolysis – relief of anxiety
Amnesia – lack of memory (antegrade and/or retrograde)

Question 2

Descr general anesthesia

Answer 2

Drug-induced loss of consciousness
Not arousable even by noxious stimulus
Often requires a controlled airway

Question 3

Descr risks of anesthesia

Answer 3

Risk of anesthesia-related death estimated 1:100,000-200,000
Pulse oximetry & capnography for all
All agents (inhalation & IV) have adverse physiologic consequences:
Respiratory depression
Cardiovascular depression
Loss (or alteration) of consciousness
Some agents may induce allergic reactions or trigger malignant hyperthermia

Question 4

Most common problems of adverse outcomes of anesthesia are?

Answer 4

Airway compromise
Medication errors
Central venous cannulation

Question 5

List some other concerns of anesthesia

Answer 5

postop nerve injury, ischemic optic neuropathy, coronary ischemia, anesthesia in remote locations, inadequate preop eval & prep

Question 6

Give the risks and benefits of preop NPO

Answer 6

Benefits
Lower risk of pulmonary aspiration
Reduce incidence of nausea & vomiting
Disadvantages
Compliance verification
Discomfort
Poor hydration
Hypoglycemia

Question 7

Factors that delay/inhibit gastric emptying are?

Answer 7

Pregnancy, obesity, abdominal mass
Hiatal hernia, GERD, tube feeding, bowel obstruction, ileus
Side effects of opioids & other medications
Ex. GLP-1 receptor agonists
Extreme age, debilitation

Question 8

List the Anesthetist’s responsibilities

Answer 8

Achieve anesthesia quickly & safely
Maintain & monitor state of anesthesia through procedure
Reverse muscle relaxation & amnesia as needed
Return patient to physiologic homeostasis (maintaining sufficient analgesia)

Question 9

Descr choice of anesthesia

Answer 9

Multiple factors in selecting technique
Some procedures require general anesthesia
ex. thoracotomy
Other procedures may be done under regional, neuraxial, or general
ex. extremity
Combination may be used

Question 10

Descr general anesthesia

Answer 10

Preoxygenation via facemask
Most anesthetics preceded by opiate
Induction commonly achieved with IV agents
Most general anesthetics include muscle relaxant
Rapid sequence induction (RSI)
Inhalation anesthetic may be used (common in children)
Combination inhalation & IV agents may be used
Maintenance commonly achieved with combination inhalation agent, nitrous oxide, opiate, & muscle relaxant

Question 11

Neuraxial (spinal & epidural) anesthesia: Descr both types

Answer 11

Types of regional anesthesia
below waist, below umbilicus, perineum (spinal)
thoracic, spine, intra-abdominal (epidural)

Question 12

Neuraxial (spinal & epidural) anesthesia:
1) Why are they used?
2) What is a common complication for both?

Answer 12

1) Provide excellent muscle relaxation, profound analgesia, avoidance of airway manipulation, allows patient to be conscious
2) Prolonged blockade of parasympathetic fibers innervating bladder (leads to urinary retention –>urinary bladder catheter)

Question 13

How is spinal anesthesia done? Where?

Answer 13

Subdural lidocaine or bupivacaine, 5-10 min onset, 2-5 hours duration
Below L2-L3 interspace (conus medullaris lies just below L1-L2 vertebral interspace)

Question 14

Descr the mc complication of spinal anesthesia

Answer 14

Most common complication is post-spinal headache
Most common in young women
1-2 days following procedure
Treat with hydration, recumbency, & analgesics (ie, Tylenol)
Severe HA may require “blood patch”

Question 15

Epidural anesthesia: Where is it done?

Answer 15

Midthoracic region for thoracotomy
Lower thoracic or lumbar region placement for abdominal or lower extremity procedures
Subdural space not entered; No CSF leak = no spinal headache

Question 16

Epidural anesthesia:
1) Descr the onset
2) What is a pro?
3) What is a con?

Answer 16

1) Much slower onset compared to spinal anesthesia
2) Insertion of small catheter allows continued use (additional anesthetic for higher block or maintenance)
3) Requires high volumes of local anesthetics

Question 17

Why is an initial small test dose done for epidural anesthesia?

Answer 17

Potential IV injection (CV compromise or high block)
Potential catheter misplacement into subarachnoid (CV collapse)

Question 18

Descr the 2 main types of peripheral nerve block

Answer 18

Upper extremity: brachial plexus blockade
Lower extremity: blockade of lumbar plexus & major branches

Question 19

Peripheral nerve block:
1) Can it be continuous?
2) What limits duration?

Answer 19

1) Catheter placement near plexus for continuous or post-op pain control (for some procedures)
2) Duration limited by tourniquets (in awake patients)

Question 20

What are some advantages of peripheral nerve blocks?

Answer 20

Avoidance of general anesthetic
Earlier discharge from recovery areas & to home
Lack of admin of large doses of opiates
Less nausea & vomiting
No instrumentation of patient airway
Earlier ambulation

Question 21

Monitored anesthesia care (MAC):
1) What is it?
2) What may be provided?
3) Who is it used for?

Answer 21

1) Previously called “local anesthesia with standby”
Caregiver monitors patient’s condition while surgeon performs procedure under local anesthesia
2) Sedation & analgesia may be provided as needed (conscious sedation)
3) Ideal for patients in frail health
Optional conversion to general anesthesia as needed

Question 22

What is done at completion of surgery?

Answer 22

Intubated patients have muscle relaxant reversed & anesthetic depth decreased
Patient extubated, transferred to stretcher, & transported to PACU
Some critically ill patients transported directly to ICU (still intubated, sedated, & ventilated)

Question 23

Post-Anesthesia Care Unit (PACU):
What is it? Explain

Answer 23

Known as “recovery room”
Post-anesthesia vital signs & initial post-op nursing care
Supplemental O2 to avoid hypoxemia
Equipped same as operating room (specialized, short-stay ICU)
Continual monitoring for ~ 1 hour or until meeting discharge criteria

Question 24

When can pts leave the PACU?

Answer 24

Discharge scoring system (Postanesthetic Discharge Scoring System) of objective criteria
Adult must escort patient home after outpatient surgery
Policies governing discharge from PACU (usually anesthesiologist along with PACU nursing team)

Question 25

What are some other PACU problems besides the MC?

Answer 25

Hypotension, hypertension Hypercapnia/hypoventilation Agitation Inability to void

Question 26

Awareness (Accidental Awareness During General Anesthesia): What is it?

Answer 26

“When a patient becomes conscious when a surgical procedure is performed under a general anesthetic and subsequently has (explicit) recall of these events.”

Question 27

Awareness (Accidental Awareness During General Anesthesia): 1) Is it common? 2) Can you reduce risk of this?

Answer 27

1) Rare under general anesthesia (reported incidence 0.1-0.2%) More common in cardiac, c-sections, and trauma/emergency surgeries under general anesthesia 2) Strategies to lower or eliminate risk incl eliminating benzos, coadministration of propofol or opiods IV, EEG monitoring

Question 28

Peripheral nerve injury: 1) When may it occur? 2) Why does it occur? Where does it occur? 3) What are the Sxs? Do they resolve?

Answer 28

1) May occur under general or regional anesthesia 2) Most always due to positioning Ulnar nerve at elbow is most common Other common sites: peroneal nerve at knee, radial nerve at humerus 3) Reported numbness & possibly motor weakness Usually resolve in short period of time Imperative to properly position & pad patients for surgery

Question 29

Malignant hyperthermia: 1) Is this serious? What is it and why does it occur? 2) What does it result with? 3) What is it common with?

Answer 29

1) True anesthesia emergency Rare, life-threatening, genetically inherited disease with intense muscle contraction Due to uncontrolled & abnormal shift of calcium in skeletal muscle 2) Results in hypermetabolic state: hyperthermia, hypercapnia, tachycardia, metabolic acidosis 3) Common with succinylcholine

Question 30

What should you do if a pt has a Hx or FHx of malignant hyperthermia?

Answer 30

No succs or volatile inhalation agent used  

Question 31

How do you Tx malignant hyperthermia?

Answer 31

Discontinuation of volatile anesthetics Hyperventilation with 100% oxygen Conclusion of surgery asap Maintenance of urine output Active cooling measures Dantrolene

Question 32

Perioperative visual loss: 1) What is it? 2) What is it assoc with? What do you do for it?

Answer 32

1) Partial or complete 2) Associated with cardiac cases or prolonged (> 6.5 hrs) spinal surgery in prone position with large blood losses -POVL most often associated with corneal abrasion: Ophthalmic consultation if no improvement in 1 day -If associated with ischemia optic neuropathy, cerebral vision loss, or central retinal artery occlusion, immediate ophthalmic consultation Risk should be discussed with patients requiring prone positioning