What are the benefits of general anesthetics (GAs) for patients undergoing surgical procedures, particularly those with significant medical histories or cardiovascular and respiratory conditions?

Benefits of General Anesthesia for Surgical Procedures

General anesthesia is reasonable and safe for patients undergoing noncardiac surgery, with both volatile agents and total intravenous techniques showing equivalent cardiac outcomes and no difference in myocardial ischemia or MI rates. 1

Core Advantages of General Anesthesia

Complete Surgical Control

• General anesthesia provides complete airway control, patient immobilization, and optimal surgical conditions without risk of inadequate anesthesia or intraoperative conversion. 2, 3
• Patients remain completely immobilized with no pain perception, allowing constant control of respiration and circulation throughout the procedure. 3
• The technique eliminates patient anxiety and is generally preferred by patients as it is less anxiety-provoking than regional techniques. 4

Cardiovascular Safety Profile

• For patients at risk for myocardial ischemia undergoing noncardiac surgery, general anesthesia demonstrates equivalent safety to regional techniques, with no significant difference in intraoperative hemodynamics, cardioactive drug use, or ischemic incidents. 5
• In a multicenter study of 214 patients aged 40-87 years at mild-to-moderate risk for myocardial ischemia, sevoflurane-N₂O showed no significant difference from isoflurane-N₂O for hemodynamics or ischemic events. 5
• Both volatile anesthetics and total intravenous anesthesia are reasonable choices, with the decision determined by factors other than prevention of myocardial ischemia and MI (Class IIa recommendation, Level of Evidence A). 1

Potential Cardioprotective Effects

• Volatile anesthetic agents have demonstrated cardioprotective benefits in cardiac surgery, though this has not been definitively proven in noncardiac surgery. 1
• Volatile agents are recommended for major noncardiac surgery in patients with heart disease based on their cardioprotective properties demonstrated in animal models and cardiac surgery. 6

Modern Agent Advantages

• The availability of short-acting agents with high clearance (propofol, desflurane, sevoflurane, remifentanil) has made general anesthesia much safer and more predictable with quick, full recovery and minimal postoperative side effects. 4
• Sevoflurane has a nonpungent odor and is particularly suitable for mask induction in pediatric patients. 5

Specific Clinical Scenarios

Obstetric Surgery

• In cesarean section, sevoflurane demonstrated equivalent safety to isoflurane with no untoward effects on mother or neonate, with Apgar scores averaging 8 and 9 at 1 and 5 minutes respectively. 5
• Neurological and Adaptive Capacity Scores were equivalent (average 29.5) between volatile agents. 5

Neurosurgery

• General anesthesia with sevoflurane or isoflurane showed no difference in intracranial pressure (ICP) response at 0.5,1.0, and 1.5 MAC concentrations during N₂O-O₂-fentanyl anesthesia. 5
• ICP response to hyperventilation (PaCO₂ from 40 to 30) was preserved with sevoflurane at both 0.5 and 1.0 MAC concentrations. 5

Hepatic and Renal Impairment

• In patients with mild-to-moderate hepatic impairment, neither sevoflurane nor isoflurane adversely affected hepatic function as measured by lidocaine MEGX assay. 5
• General anesthesia can be safely administered in patients with compromised organ function when appropriately managed. 5

Safety Record in Office-Based Settings

• An 18-year consecutive study of more than 23,000 office-based procedures under general anesthesia reported zero intraoperative or postoperative deaths and no significant complications. 7
• This contradicts the common perception that general anesthesia is too risky for aesthetic surgery procedures. 7

Important Caveats

Comparison to Regional Techniques

• General anesthesia shows no cardioprotective advantage over neuraxial techniques for intraoperative management in eligible patients. 1
• For abdominal aortic surgery specifically, neuraxial anesthesia for postoperative pain relief can be effective to reduce MI (Class IIa, Level B), though this benefit relates to postoperative analgesia rather than the intraoperative anesthetic choice. 1

Monitored Anesthesia Care Considerations

• While general anesthesia is safe, monitored anesthesia care (MAC) was associated with the highest 30-day mortality in one large-scale study, likely reflecting selection bias where patients with significant comorbidities were chosen for MAC rather than general anesthesia. 1
• MAC provides poor blockade of stress response unless the regional block provides profound anesthesia, and inadequate blocks may require excessive sedation, potentially negating safety advantages. 8

Pediatric Considerations

• Sevoflurane use has been associated with seizures, predominantly in children and young adults starting from 2 months of age, requiring clinical judgment in patients at risk for seizures. 5
• Cases of life-threatening ventricular arrhythmias have been reported in pediatric patients with Pompe disease after sevoflurane induction. 5