What are the recent updates in routine general anesthesia practice for a healthy 70‑kg adult (American Society of Anesthesiologists physical status I‑II, age 18‑65 years) with no organ dysfunction?

Recent Updates in General Anesthesia Practice

Neuromuscular Blockade Management

Quantitative neuromuscular monitoring must be used routinely to verify Train-of-Four (TOF) ratio >90% before extubation when neuromuscular blocking agents are administered. 1, 2 This represents a critical shift from qualitative assessment, as residual paralysis is a major avoidable complication. 1

• Use sugammadex for rapid reversal of rocuronium or vecuronium-induced blockade rather than relying solely on neostigmine, as it achieves TOF ratio of 0.9 in median times of 2.7 minutes (rocuronium) and 3.3 minutes (vecuronium) when administered at reappearance of T2. 3

• Administer sugammadex 2 mg/kg at reappearance of T2 (moderate blockade) or 4 mg/kg at 1-2 post-tetanic counts (deep blockade) for rocuronium or vecuronium reversal. 3

• If quantitative monitoring shows unreliable signal (calibration error, patient movements, defective sensors), systematically antagonize neuromuscular blockade rather than proceeding to extubation. 1

Depth of Anesthesia Monitoring

BIS or entropy monitors should be used routinely to guide anesthetic depth, particularly in patients at higher risk of adverse outcomes including those over 60 years. 1, 2 This prevents relative overdose and reduces postoperative delirium.

• Target BIS values of approximately 50 rather than 35 to reduce postoperative delirium incidence in older patients. 2

• **Avoid BIS values <40 and burst-suppression patterns** on processed EEG in patients >60 years, as these are associated with increased delirium. 2

• The "triple low" phenomenon (low BIS, hypotension, low inspired anesthetic concentration) is associated with higher mortality and prolonged hospital stay. 1

Anesthetic Agent Selection and Dosing

Use rapidly reversible agents—propofol and sevoflurane are the hypnotics of choice—to optimize conditions while allowing rapid return of spontaneous ventilation if needed. 1

• Employ short-acting volatile agents (sevoflurane or desflurane) to facilitate rapid emergence and early return of protective reflexes. 2

• Reduce all induction agent doses by 30-50% in elderly patients due to age-related pharmacokinetic/pharmacodynamic changes causing myocardial depression and impaired blood pressure homeostasis. 4, 5

• Fentanyl requirements decrease by 10% per decade of age from peak dose to age 80 years; propofol by 8%, thiopental by 6%, and isoflurane by 4% per decade. 5

• If using age-adjusted MAC values without depth monitoring, employ a Lerou nomogram to calculate appropriate inhalational anesthetic doses. 1

Airway Management Strategy

Maintain deep anesthesia using rapidly reversible agents to optimize mask ventilation and intubation conditions when difficult intubation is anticipated. 1

• Administer a short-acting muscle relaxant (succinylcholine 1 mg/kg) or one that can be rapidly inactivated when difficult intubation is expected, as this increases success rates. 1

• Quantitatively assess neuromuscular blockade level using a monitor—there is no published data supporting testing mask ventilation before administering neuromuscular blocking agents. 1

• Extubate patients while awake unless there is specific medical or surgical contraindication (e.g., to prevent coughing), particularly in patients at increased perioperative risk. 1

• Verify full reversal of neuromuscular blockade before extubation. 1

Multimodal Analgesia Approach

Implement scheduled (not PRN) multimodal analgesia to reduce opioid consumption and prevent serum level fluctuations. 2

• Administer acetaminophen 1 g IV intraoperatively, then 1 g PO every 6 hours on a fixed schedule for consistent baseline analgesia. 2

• Include gabapentin 300-600 mg preoperatively, then 300 mg three times daily for opioid-sparing and neuropathic pain control. 2

• Prescribe scheduled NSAID (celecoxib 200 mg twice daily for 48 hours) after surgical approval to augment analgesia while monitoring bleeding risk. 2

• Reduce total opioid dose by 20-25% per decade after age 55, reflecting decreased requirements in older adults. 2

• Use scheduled tramadol as baseline opioid, reserving stronger opioids (oxycodone) for breakthrough pain only. 2

Hemodynamic Management

Establish intra-arterial blood pressure monitoring before induction in elderly patients to identify and treat frequent induction-related hypotension. 2

• Maintain systolic arterial pressure within ±10% of pre-induction baseline to reduce postoperative delirium and cognitive decline. 2

• Define hypotension as >20% drop in systolic pressure from baseline and implement immediate corrective measures at this threshold. 2

• Administer fluid in small divided boluses of approximately 250 mL to allow assessment of responsiveness in patients with reduced homeostatic compensation. 1, 2

• Avoid prolonged preoperative fasting; allow clear fluids up to 2 hours before surgery to prevent dehydration. 1

Temperature Management

Maintain core temperature >36°C throughout the procedure using forced-air warming and fluid-warming systems to prevent hypothermia-related coagulopathy, increased bleeding, and delayed wound healing. 1, 2

• Use continuous temperature monitoring (tympanic, pharyngeal, or esophageal) as older adults are more prone to hypothermia and harder to rewarm. 2

• Continue warming during transport to and from the operating theater. 2

PONV Prophylaxis

Provide 2-3 antiemetic agents from different pharmacologic classes for high-risk patients receiving opioids. 2

• Administer dexamethasone 4-8 mg IV at induction for antiemetic effect without increasing wound infection risk. 2

• Give ondansetron 4 mg IV at end of surgery as 5-HT₃ antagonist. 2

• Consider NK1-receptor antagonist (aprepitant) for very high-risk patients, with appropriate QTc monitoring when multiple agents are used. 2

Regional Anesthesia Considerations

Regional anesthesia with minimal or no sedation may reduce hypotension, delirium, cardiorespiratory complications, and opioid requirements compared to general anesthesia in elderly patients. 2, 4

• However, patients with pre-existing cognitive dysfunction may be unable to tolerate regional anesthesia without deep sedation, which negates the cognitive-preserving advantage. 4

• Reduce local anesthetic doses by 30-50% in elderly patients due to increased sensitivity from age-related neural changes. 4

• Major conduction anesthesia (spinal/epidural) should be considered for peripheral procedures. 1

Positioning and Pressure Injury Prevention

Comprehensively pad all potential sites of nerve or pressure injury before incision and reassess at least every 30 minutes during the case. 2

• Elderly patients have thinner skin, reduced vascularity, and diminished muscle bulk, increasing susceptibility to pressure necrosis over bony prominences (especially heels). 2

• Exercise extra caution when transferring patients and removing adhesive devices due to fragile skin. 2