POA EXAM 3: Induction & Emergence

What are the major types of anesthesia listed in the induction/emergence notes?

Local anesthesia, regional anesthesia, sedation/monitored anesthesia care (MAC), and general anesthesia.

What are the three main goals of anesthesia?

Analgesia, amnesia, and akinesis; these help determine anesthetic type and depth.

How is local anesthesia described?

It numbs a localized nerve region for less invasive surgery; sedation may not be needed unless the patient is anxious.

How is MAC/sedation described in the notes?

A twilight/semi-unconscious state where the patient is sleepy, spontaneously breathing, usually maintains BP/HR, and may remember events.

What is topical local anesthesia used for in the notes?

EMLA cream for IV placement.

What is infiltration anesthesia and when is it used?

Local anesthetic is injected into subcutaneous tissue to block sensory nerves in a specific area; used for superficial/smaller procedures like cyst removal.

What is a Bier block and why is it not used often?

An IV regional block using tourniquet isolation and large-volume local anesthetic distal to the cuff; not used frequently due to LAST risk.

How is local anesthetic handled during and after a Bier block?

The tourniquet keeps LA in the arm bathing terminal nerves; cuffs are released gradually after enough LA is absorbed/metabolized/eliminated to limit systemic toxicity.

How do field blocks work?

Large volumes of LA are injected in the plane of a target nerve bundle so it absorbs anesthesia; they are less specific than PNBs.

What are examples and key features of field blocks?

Examples: ankle block, TAP block. They can be done by anatomy without ultrasound; aspirate and inject in different areas.

How do peripheral nerve blocks differ from field blocks?

PNBs are more specific; ultrasound identifies nerve roots/bundles and LA is injected around the nerve base.

When can a peripheral nerve block be the primary anesthetic?

When it blocks surgical stimulation well enough; no other anesthesia may be needed, though sedation can be added for comfort.

What does a peripheral nerve block prevent?

Sensory stimulation to branches distal to the nerve root.

What are examples of peripheral nerve blocks listed?

Brachial plexus, adductor canal, and popliteal blocks.

What are neuraxial blocks and examples?

Spinal and epidural blocks; examples include total joint surgery, labor and delivery, and C-section.

Where are neuraxial blocks injected and what area do they affect?

Injected into intrathecal or epidural space; they can run up the entire lower half.

When sedation is added to local/regional anesthesia, what is its role?

Sedation is supplemental for comfort; local/regional anesthesia remains the primary anesthetic.

What does MAC officially describe?

A specific anesthesia service by a qualified anesthesia provider for a diagnostic or therapeutic procedure; it does not describe sedation depth.

Why is MAC considered broad terminology?

The provider can titrate sedation to different depths, including potential conversion to general or regional anesthesia.

What terms are more specific than simply saying MAC?

Light/minimal, moderate, and deep sedation.

What characterizes minimal sedation?

Often for eye/endoscopic surgery; usually a little Versed/fentanyl; patient responds to speech, spontaneously ventilates, and maintains CV function.

What characterizes moderate sedation?

Patient is sleepy when unstimulated but opens eyes with arousal or movement; may use propofol or another sedative.

When might moderate sedation be useful?

Anxious patients or total joint surgery with spinal anesthesia when OR noise/tourniquet discomfort is an issue.

What characterizes deep sedation?

Higher propofol; unconscious; no response to speech or limb movement; may respond to painful stimulation.

What are airway/ventilation expectations in deep sedation?

The patient breathes spontaneously and usually maintains CV function, but the airway may be compromised.

How can OSA affect deep sedation airway management?

The tongue may fall back and obstruct; use an oral airway if needed, not an LMA just to hold the airway open.

When should deep sedation be converted to general anesthesia?

If surgical stimulation is too painful or cannot be covered by deep sedation with local anesthesia.

What characterizes general anesthesia?

Unconsciousness with blunted respiratory/CV function; may require ETT/LMA and pressors.

What factors determine the depth of anesthesia needed?

Surgical stimulation, how involved the surgery is, and how sick the patient is.

How should anesthesia be approached in sicker patients when possible?

Use local/regional anesthesia to cover pain and keep sedation minimal/moderate if respiratory/CV support is not needed.

What must you always be ready to do during sedation?

Transition to general anesthesia.

Who are good candidates for conscious sedation?

Patients with reassuring airway, cooperative behavior, and ASA I-II status.

Who are poor candidates for conscious sedation?

Emergency/full stomach patients, difficult airway patients, ASA ≥III patients, and patients requiring high-dose narcotics.

Why is full stomach a concern for deep sedation?

Reflexes may be blunted in a semi-conscious state, increasing vomiting/aspiration risk.

What anesthetic approach is suggested for full stomach/high aspiration risk?

General anesthesia with ETT and inflated cuff to help protect lungs from aspiration.

Why is difficult airway concerning during moderate/deep sedation?

Sleepiness can cause airway compromise; it is not the time to struggle with an airway when breathing is already compromised.

What is Guedel Stage 1?

Analgesic state; patient can still talk; fentanyl/lidocaine may be given.

What is Guedel Stage 2 and why is it dangerous?

Delirium stage with dysconjugate eyes, unresponsiveness, hyperactive reflexes, and high laryngospasm risk; do not stimulate or intubate here.

When is Stage 2 more commonly seen?

With inhalation induction, especially pediatrics; IV induction usually skips to Stage 3.

Why is inhalation induction common in pediatrics?

Children may not allow IV placement beforehand, so they are induced with gas.

What is Guedel Stage 3?

Surgical anesthesia stage; desired stage for unresponsiveness and muscle relaxation.

What are Stage 3 planes 1-2 useful for?

LMA placement; patient may still breathe with support; eyelid/corneal reflexes are lost.

What are Stage 3 planes 3-4 useful for?

ETT placement; more breathing support; pupillary light reflex, glottic reflex, and all reflexes are lost.

What is Guedel Stage 4?

Medullary depression; avoid this because hemodynamic and full physiologic support are needed.

What should be done instead of going to Stage 4 to prevent movement?

Keep the patient at Stage 3 and paralyze them if appropriate.

How are Guedel stages related to inhalation vs IV agents?

They apply to both, but are more prominent with inhalation agents.

What is MAC Awake?

0.3-0.5 MAC; 50% will not respond to command; associated with amnesia and light anesthesia/Stages 1-2.

What is MAC 1.0?

Standard anesthetic dose where 50% will not move to surgical stimulus.

What is MAC BAR?

1.5-2.0 MAC; 90-95% will not move to surgical stimulus; BAR = blunting adrenergic response; associated with CV depression/Stage 4 risk.

When can paralytic be added to prevent movement?

If the patient still moves to surgical stimulus, but only if they have an ETT.

What should be reviewed in the chart during pre-anesthetic evaluation?

Medications, anesthetic history, medical history, labs, EKG, and imaging.

What airway assessment items are listed?

Mallampati/MP score, neck ROM, mouth opening, upper lip bite test, and facial hair.

What is noted about MP 1 and MP 2?

MP1: vocal cords wide open. MP2: can still see vocal cords.

What is noted about MP 3?

Not a horrible intubation status; tongue may be larger; cannot see cords; may need bougie or GlideScope because DL may have poor view.

What is noted about MP 4?

Difficult airway; cannot see cords; mouth may be too small for tongue; hard to maneuver tools.

What does MSMAIDS stand for?

Machine, suction, monitors, airway, IV, drugs, and special equipment.

What machine checks are listed?

AGM, volatile level, emergency Ambu-bag, and O2 source.

What suction setup is required?

Suction on, working, clean, attached to Yankauer/canister; on max at first; can clamp tubing to stop noise.

What monitors are listed for induction setup?

ECG, pulse oximeter, NIBP, and temperature; get all numbers before starting anesthesia.

What airway equipment is listed for setup?

ETT/LMA, adjuncts/backups, blades, bite blocks, and tongue depressor.

What airway equipment is suggested for the appendectomy case?

About 7.5-8.0 ETT with backup sizes, blade, GlideScope, and oral airway available.

Why might GlideScope be chosen early in the case?

DL attempts can increase aspiration risk and the airway needs to be secured quickly.

What IV setup points are listed?

Check supplies if needed, IV patency/location, and fluids; most appendectomy patients may only need one IV.

What drug setup is required?

Prepare induction medications and emergency medications.

What special equipment is listed?

Positioning equipment, PNS/TOF, Bair Hugger, OGT/NGT, eye tape, and possibly BIS/temp probe.

When and why are eyes taped?

Before intubation to prevent corneal abrasion.

When might BIS be used?

If worried about running the patient too deep or doing half gas/half TIVA.

Why are OGT and TOF relevant in laparoscopic/robotic cases?

OG after asleep; TOF because the patient is paralyzed.

What are the first steps of standard induction?

Premedicate if needed, place monitors, perform time-out, and preoxygenate/denitrogenate.

When might premedication be used or avoided?

Use if anxious; consider avoiding in elderly/confused patients.

What is the preoxygenation goal?

EtO2 80-90% for about 3 minutes or 5 large breaths with a good mask seal.

What apnea-time and patient-size points are listed for preoxygenation?

Good preoxygenation gives about 8 minutes apnea time; larger patients have less due to decreased FRC.

What EtO2 is acceptable but less ideal?

70% is acceptable, but 80-90% is preferred if intubation may be difficult.

How should the bed be positioned for induction?

Bed height between your xiphoid and belly button, with the patient's head near that level.

What medication sequence is used for typical induction?

Amnestic optional → analgesic → sedative → confirm LOC/lash reflex → paralytic.

How do you assess loss of consciousness/lash reflex?

Call the patient's name and confirm they are not arousable and not blinking.

What should be done before paralytic in standard induction?

Attempt bag-mask ventilation first.

What APL setting is used for initial mask ventilation?

APL closed to about 10-20 cm H2O.

Why keep mask ventilation pressure under 20 cm H2O if possible?

To reduce stomach insufflation.

What do you do if mask ventilation is poor?

Check seal/chest rise, reposition, add OPA/NPA, ask for help; if saturation drops, increase APL as needed and consider succinylcholine/RSI-dose rocuronium.

Why confirm mask ventilation before routine paralytic?

If you cannot ventilate after paralytic, you must wait for it to peak while the patient desaturates.

"What does 'mask them to the peak of paralytic' mean?"

Continue ventilation until the paralytic has reached optimal intubating conditions.

What are the standard intubating doses and wait times for common paralytics?

Rocuronium 0.6 mg/kg wait 90-120 sec; vecuronium 0.1 mg/kg wait 2-3 min; cisatracurium 0.1-0.2 mg/kg wait 2-3 min.

When may TOF be checked during induction?

Before intubation, though often clinicians assume optimal conditions after the expected onset time.

What should you do if the cords are closed during laryngoscopy?

Take the blade out and wait longer before trying again.

What are key DL technique points?

Blade in left hand, scissor mouth open, sweep tongue, verbalize view, pass ETT with right hand while watching it pass through cords.

What should happen after ETT passes through the cords?

Have stylet removed while holding tube, remove blade, turn APL to 20, ventilate to confirm placement, and do not forget to turn ventilator on.

How is ETT placement verified?

ETT condensation, chest rise, sustained EtCO2, and bilateral breath sounds.

What is the gold standard for confirming ETT placement in the notes?

Normal-range EtCO2 for at least 3 breaths.

What suggests esophageal intubation or right mainstem intubation?

Esophageal: EtCO2 trails off. Right mainstem: right breath sounds louder than left due to tube too far down.

What should be done after confirming ETT placement?

Secure tube, switch to ventilator, turn on VA, turn down O2 flow/FiO2, maintain vigilance, place Bair Hugger, and document.

What is the preferred general profile of induction medications?

Fast on/off and reversible when possible.

What are the dose, MOA, effects, and reversal for midazolam?

1-2 mg IV; GABA(A) modulator; anxiolytic, sedative, amnestic, anticonvulsant; reversed by flumazenil.

What important issue is listed with flumazenil?

Its duration may be shorter than the benzodiazepine, so redosing may be needed.

What are the dose and MOA of IV lidocaine for induction?

1-1.5 mg/kg IV; voltage-gated Na+ channel blocker inhibiting neuronal depolarization —> motor/sensory blockade dep on fiber; effect: pain —> temp —> touch —> proprioception —> skeletal fx; blunts autonomic response (hemodynamic response to intubation)

Why is lidocaine used during induction?

It decreases propofol burn and blunts hemodynamic reflex response to intubation.

What additional lidocaine details are listed?

Class Ib antiarrhythmic; can block K+ and L-type Ca2+ channels; common IV concentrations are 1% and 2%.

What is the lidocaine LAST dose listed?

4.5 mg/kg, increased to 7 mg/kg with epinephrine due to less systemic absorption.

What are the dose, MOA, and effects of fentanyl?

50-100 mcg; Mu opioid agonist: inhibits adenylate cyclase —> decreases cAMP/Ca2+ conductance + increases K conductance —> analgesia ; analgesia, euphoria, drowsiness, and nausea/vomiting.

How is fentanyl described compared with other opioids?

Highly potent with faster onset and shorter duration.