Anesthesia

Responsibilities of anesthesiologist

1. Induction

2. Amnesia

3. Analgesia

4. Secure airway/monitoring

5. Safe emergence/reversal of NMBA

6. Treatment of any anesthesia emergencies during induction, procedure, emergence

Most important risk factor for anesthesia complications

cardiac

Revised cardiac risk index

1. High-risk surgery (e.g., vascular, intraperitoneal, intrathoracic)

2. History of ischemic heart disease (e.g., angina, MI)

3. History of congestive heart failure (CHF)

4. History of cerebrovascular disease (e.g., stroke, TIA)

5. Pre-op insulin use

6. Creatinine >2.0 mg/dL

Should beta blockers and statins be discontinued perioperatively for cardiac patients?

no. continue meds

renal considerations for anesthesia

1. fluid balance

2. electrolytes

3. renal dosing

Signs of liver disease

Ascites

Hypoalbuminemia

Coagulation disorders

→ affects Anesthetic metabolism

which DM has higher risk of hypo/hyperglycemia

Type 1- higher risk for hyper and hypogylcemia

when should metformin be held before anesthesia for DM2

24 hrs prior to anesthesia

why should you check for thyroid labs and symptoms before surgery

concern for thyroid storm w the stress surgery has on body

What neurologic conditions are important to assess preoperatively for anesthesia, and why?

Intracranial mass, midline shift, or ↑ intracranial pressure (ICP)

bc → Risk of brain herniation with anesthesia induction

thyroid meds during surgery?

CONTINUE MEDS!

perioperative NSAIDs?

HOLD 72 hours bc bleeding risk

GLP-1 risk w anesthesia

delays gastric emptying → inc risk of aspiration

hold or continue ACE/ARBs for BP during surrgery

HOLD! (but dont d/c BB)

upper airway examination

1. Cervical spine ROM

2. Thyroid cartilage to mentum distance

3. Mouth opening

4. Dentition

5. Jaw alignment

6. Facial hair (interfere w mask seal)

7. Mallampati classification score

classify

Mallampati Class 1

Classify

mallampati class 4

classify

mallampati class 2

classify

mallampati class 3

Risk factors for difficult airway

1. Prior difficult airway

2. Increased neck circumference

3. Secretions or blood in airway

4. Short neck

5. Large tongue

What ASA classification: normal and healthy without acute or chronic disease

ASA 1

What ASA classification: Mild systemic disease without substantive functional limits

ASA 2

What ASA classification: severe systemic disease with substantive functional limitations

ASA 3

What ASA classification: severe systemic disease w a constant threat to life

ASA 4

What ASA classification: moribund and not expected to survive without surgery

ASA 5

What ASA classification: brain dead; organs removed for donation

ASA 6

components of anesthesia informed consent

1. Role of anesthesia provider

2. Review of medical history

3. Review of NPO time

4. Plan for pre-medication, induction, plan for airway management, plan for recovery/pain management

5. Discussion of increased risks based on particular comorbidities  (cardiac, neurologic, respiratory)

6. PONV

7. Aspiration

8. Injury to teeth/dental work

9. Damage to vocal cords

10. Rare complication of needing higher level of care- ICU admission, intervention, procedure, surgery

11. Answer questions/concerns

12. Written or verbal

minimum fasting after having clear liquids by mouth

2 hours

minimum fasting after having non-clear liquids or LIGHT meal

6 hours

minimum fasting after fried, fatty foods or meat

8 hours or more

general anesthesia vs sedation

general anesthesia → fully unconscious

sedation → decreased level of consciousness but not fully

order of general anesthesia

1. pre-oxygenate

2. mask/IV induction

3. patient unconscious

4. airway management

5. maintain anesthesia

6. emergence/ reversal of anesthesia agent

which general anesthetic causes cardiovascular stimulation rather than depression

ketamine (protective airway but cause delirium and hallucinations)

Etomidate uses

RSI, induction of anesthesia

Fluorinated ethers vs nitrous oxide

Fluorinated ethers has less risk of post-op nausea and vomitting

which general anesthetic helps w post-op cognitive and behavioral dysfunction

Dexmedetomidine

Neuromuscular Blocking Agents (NMBAs) purpose

paralyze voluntary muscles and decrease muscle tone

*NO sedation or analgesic effects

depolariizing NMBA

succinylcholine

non-depolarizaing NMBA

1. Rocuronium

2. vecuronium

NMBA reversal agents

1. neostigmine

2. sugammadex

Possible analgesics

1. Opioids→ Analgesia, supplement sedation, post-op pain management

2. NSAIDS

3. Ketamine

4. Tylenol

Antiemetic options

1. Ondansetron

2. Metoclopramide

3. Dexamethasone

4. Meclizine/promethazine

5. Scopalomine

what is monitored anesthesia care (MAC)

anesthesia where pt is sedated but can breath on own (natural airway) →

IV sedation + local anesthetic and then monitor throughout to readily adjust or convert to general anesthesia if needed

Pros and cons of MAC over general anesthesia

1. less side effects

2. less airway injury risk

3. faster cognitive recovery

cons:

1. more frequent hypoexmic episodes than general anesthesia

2. can over sedate → apnea

3. challenging emergency airway management

whats procedural sedation

done by physician performing procedure, not anesthesiologist

administer sedatives/analgesics during procedure

difference between spinal and epidural anesthesia

epidural leaves catheter in epidural space while spinal is just a shot

4 things monitored for anesthesia

1. Oxygenation →pulse ox

2. Ventilation →Capnography

3. Circulation → EKG, arterial blood pressure monitor, HR

4. Temp → oral, skin, nasal, or bladder temp probes

complications of anesthesia

1. Malignant hyperthermia

2. Pseudocholinesterase deficiency

3. Anesthesia Awareness

4. Hypothermia

5. PONV

6. Peripheral Nerve Injury

7. Respiratory, cardiac and neurologic complications

how to recognize malignant hyperthermia early

check core temp

how to treat malignant hyperthermia

1. stop triggering agent

2. intubate

3. dantrolene

malignant hyperthermia

rare genetic reaction to certain anesthetics causing abnormal calcium release which leads to rapid muscle contraction, high fever, and a life-threatening metabolic crisis.

Pseudocholinesterase Deficiency

deficiency in Pseudocholinesterase enzyme that breaks down NMBA like succinylcholine → prolonged paralysis

just need to be sedated and ventilated til muscle strength returns

anesthesia awareness is associated with

1. NMBA (pt cant move to to signal awareness)

2. Total Intravenous Anesthesia (TIVA)

risk factors for post op nausea and vomiting

1. Female sex

2. History of PONV or motion sickness

3. Non-smoker

4. Postoperative opioid use

5. Use of volatile anesthetics and nitrous oxide