What type of anesthesia is recommended for medical procedures?

Anesthesia Selection for Medical Procedures

Primary Recommendation

The choice of anesthesia type should be determined by the specific procedure, patient comorbidities, and surgical requirements rather than a single universal approach, with four main classifications available: local anesthesia, regional anesthesia (including peripheral nerve blockade and neuraxial blockade), monitored anesthesia care (MAC), and general anesthesia. 1

Classification of Anesthesia Types

Local Anesthesia

• Lidocaine is the most commonly used agent for office-based dermatologic and minor surgical procedures 2
• Topical anesthetics are recommended as first-line for dermal laceration repair, especially in children, minor skin procedures including small biopsies and excisions, and nonablative laser treatments 2
• Infiltrative local anesthesia is recommended for larger incisions and excisions, procedures requiring deeper tissue manipulation, and areas with thicker skin where topical agents may be insufficient 2

Regional Anesthesia

• Includes peripheral nerve blockade and neuraxial blockade (epidural or spinal anesthesia) 1
• For lower-limb revascularization, neuraxial anesthesia shows no cardioprotective benefit over general anesthesia, with equivalent 4% MI rates in both groups 1
• For abdominal aortic surgery, thoracic epidural combined with light general anesthesia demonstrates no significant difference in myocardial ischemia and MI rates compared to general anesthesia alone 1
• Neuraxial anesthesia for postoperative pain relief can be effective in patients undergoing abdominal aortic surgery to decrease the incidence of perioperative MI 1
• Perioperative epidural analgesia may be considered to decrease the incidence of preoperative cardiac events in patients with hip fracture 1

Monitored Anesthesia Care (MAC)

• Involves intravenous sedation with or without local anesthesia 1
• MAC is the first choice in 10-30% of all surgical procedures 3
• The three fundamental elements are: safe sedation, control of patient anxiety, and pain control 3
• Patients undergoing conscious sedation are able to respond to commands appropriately and protect airways 3

General Anesthesia

• Includes volatile-agent anesthesia, total intravenous anesthesia, or a combination of both 1

General Anesthesia: Volatile vs. Total Intravenous Anesthesia

Use of either a volatile anesthetic agent or total intravenous anesthesia is reasonable for patients undergoing noncardiac surgery, and the choice is determined by factors other than the prevention of myocardial ischemia and MI 1

Evidence Base

• A meta-analysis of >6000 patients undergoing noncardiac surgery demonstrated no difference in MI rates between patients who received volatile anesthesia versus total intravenous anesthesia 1
• Although volatile anesthetic agents show benefit in cardiac surgery, reduction in myocardial ischemia or MI has not been demonstrated in noncardiac surgery 1
• Randomized comparison of volatile versus total intravenous administration in noncardiac surgery showed no difference in either myocardial ischemia or MI 1

Multimodal Anesthesia Approach

Preemptive and multimodal anesthesia and analgesia should be employed for all painful procedures 1

Key Principles

• Preemptive refers to administration of analgesics before the painful insult to minimize postprocedure pain, usually given at time of anesthetic induction 1
• Multimodal anesthesia refers to using different pharmacological classes of anesthetics and analgesics to minimize pain 1
• Combine local anesthesia at the site of incision with systemic administration of opioids and nonsteroidal anti-inflammatory drugs 1
• Frequently used anesthetics in rodents (e.g., gas anesthesia) have generally no or minimal analgesic properties and therefore require additional analgesics 1

Specific Agent Selection

Propofol for Induction and Maintenance

• Most adult patients under 55 years of age classified as ASA-PS I or II require 2 mg/kg to 2.5 mg/kg of propofol for induction when unpremedicated or premedicated with oral benzodiazepines or intramuscular opioids 4
• For elderly, debilitated, or ASA-PS III or IV patients, approximately 1 mg/kg to 1.5 mg/kg (approximately 20 mg every 10 seconds) is required for induction 4
• A rapid bolus should not be used in high-risk patients, as this will increase the likelihood of undesirable cardiorespiratory depression including hypotension, apnea, airway obstruction, and/or oxygen desaturation 4
• For maintenance, anesthesia can be maintained by administering propofol by infusion at 100 mcg/kg/min to 200 mcg/kg/min with 60% to 70% nitrous oxide and oxygen 4

Inhaled Anesthetics

• Desflurane, isoflurane, and sevoflurane are preferred because they have adequate potency, appropriate solubility, and minimal to no risk for hepatotoxicity 5
• Nitrous oxide potency is too small to produce anesthesia by itself 5
• Halothane is too soluble and poses a risk of severe hepatotoxicity 5

Special Population Considerations

Duchenne Muscular Dystrophy Patients

• Inhaled anesthetic agents such as halothane, isoflurane, and sevoflurane should be considered contraindicated for patients with DMD due to increased risk for extreme hyperthermic events and rhabdomyolysis 1
• Succinylcholine is contraindicated in patients with DMD due to risk of acute rhabdomyolysis, hyperkalemia, and cardiac arrest 1
• Procedural sedation should be performed with an anesthesiologist in attendance and with full monitors and safety measures 1

COPD Patients

• COPD significantly increases the risk of postoperative pulmonary complications during general anesthesia, with patients having a 2.7-4.7-fold higher risk compared to those without COPD 6
• Preoperative FVC < 50% of predicted indicates increased risk, while FVC < 30% of predicted indicates high risk for respiratory complications 6
• Continue beta-adrenergic agonists and anticholinergic agents until the day of surgery in symptomatic COPD patients 6
• Consider preoperative training in the use of noninvasive positive pressure ventilation (NPPV) for high-risk patients 6

Critical Safety Principles

Anesthetic Depth

• Painful procedures must only be performed when achieving surgical plane of anesthesia (i.e., pain reflexes absent) 1
• Anesthetic depth and duration should be appropriate to the scope and duration of the procedure 1

Perioperative Care

• Animals/patients should be kept warm in the pre-, intra- and postoperative phase 1
• Vital signs and reflexes should be checked on a regular basis to confirm the appropriate level of anesthesia 1
• Monitoring equipment (e.g., electrocardiogram, pulse oximeter) should be used for more complicated surgical procedures 1

Drug Interactions

• The induction dose requirements of propofol may be reduced in patients with intramuscular or intravenous premedication, particularly with narcotics and combinations of opioids and sedatives 4
• The concomitant use of valproate and propofol may lead to increased blood levels of propofol; reduce the dose of propofol when co-administering with valproate 4

Common Pitfalls

• Performing incisions without anesthesia is not appropriate standard of care in modern medical practice 2
• Rapid bolus administration in elderly, debilitated, or ASA-PS III or IV patients increases cardiorespiratory effects including hypotension, apnea, airway obstruction, and oxygen desaturation 4
• Failure to reduce the infusion rate in patients receiving propofol for extended periods may result in excessively high blood concentrations 4
• At least 3 deaths have been reported due to failure to reactivate ICD tachytherapies in patients who had ICD therapy inactivated preoperatively 1