What is the recommended anesthetic plan for a 74-year-old female with ASA 3 status, Type 2 Diabetes Mellitus, and hypertension, undergoing laparoscopic cholecystectomy?

Anesthetic Plan for 74-Year-Old ASA 3 Patient Undergoing Laparoscopic Cholecystectomy

Your proposed plan of GETA with midazolam, remifentanil, ketofol, rocuronium RSI, and remifentanil/sevoflurane maintenance is reasonable, but requires several critical modifications to optimize outcomes in this elderly, obese patient with comorbidities.

Critical Pre-Operative Considerations

Age-Related Pharmacology

• Reduce all induction doses by 30-50% from standard adult dosing due to age-related alterations in pharmacokinetic and pharmacodynamic profiles that render elderly patients sensitive to relative overdose, resulting in myocardial depression and reduced blood pressure homeostasis 1.
• The dose required to induce anesthesia is lower and onset time is longer in patients over 74 years 1.
• Implement depth of anesthesia monitoring (BIS or entropy) to prevent excessive anesthetic depth and facilitate faster emergence 1.

Obesity Considerations (89kg)

• Assume significant sleep-disordered breathing regardless of formal testing and modify technique accordingly 1.
• Position patient in 25-30 degree head-up (ramped) position with tragus level with sternum for pre-oxygenation, induction, intubation, and throughout surgery to optimize respiratory mechanics 1.
• Calculate rocuronium dosing based on ideal body weight, not actual weight 1.
• Ensure two large-bore IV cannulae are secured before induction, potentially using ultrasound guidance or considering unusual sites (upper arm, anterior chest wall) 1.

Diabetes Management

• Avoid prolonged preoperative fasting - clear liquids up to 2 hours before induction are safe 1.
• Monitor and prevent both hyperglycemia and hypoglycemia intraoperatively as both worsen outcomes 1.
• Type 2 diabetes is not a contraindication to carbohydrate loading 1.

Modified Induction Plan

Pre-Oxygenation

• Pre-oxygenate for minimum 5 minutes in 25-30 degree head-up position to maximize oxygen reserve 1.
• Consider CPAP during pre-oxygenation if patient uses it at home 2.

Induction Sequence

• Reduce midazolam to 1-2 mg maximum (not weight-based) as benzodiazepines cause cognitive impairment and increase delirium risk in elderly patients 1.
• Ketamine component of "ketofol" should be limited - while ketamine-midazolam combinations are effective 3, 4, the elderly are more sensitive to all agents 1.
• Propofol dose should be reduced by 30-50% from standard adult dosing 1.
• Rocuronium dosing based on ideal body weight with sugammadex immediately available and pre-calculated for emergency reversal 1.

RSI Considerations

• RSI is appropriate given obesity and laparoscopic procedure, but be prepared for potentially difficult airway 1, 2.
• Rocuronium minimizes apnea time if bag-mask ventilation proves difficult 1.

Maintenance Anesthesia

Volatile Agent Selection

• Sevoflurane is acceptable but desflurane is superior in obese patients, providing faster return of airway reflexes 1.
• Commence maintenance promptly after induction due to increased risk of awareness in obese patients 1.
• Use depth of anesthesia monitoring to limit anesthetic load, particularly important with neuromuscular blockade 1.

Remifentanil Infusion

• Remifentanil is an excellent choice as a short-acting agent that facilitates rapid emergence 1.
• Implement multimodal opioid-sparing analgesia including local anesthetic infiltration by surgeon 1.

Ventilation Strategy

• Use pressure-controlled ventilation with PEEP 8-10 cmH2O and recruitment maneuvers to reduce atelectasis 1.
• Maintain slight sitting position (flexed trunk) during laparoscopy to allow increased abdominal excursion and lower airway pressures 1.
• Calculate tidal volumes based on ideal body weight (6-8 mL/kg IBW) 1.

Intraoperative Monitoring

• Implement quantitative neuromuscular monitoring to maintain appropriate block level and ensure complete reversal 1.
• Monitor blood pressure closely - elderly patients have reduced blood pressure homeostasis 1.
• Consider arterial line if significant hemodynamic instability anticipated 1.

Emergence and Extubation Plan

Neuromuscular Reversal

• Use quantitative neuromuscular monitoring - aim for train-of-four ratio >0.9 before extubation 1.
• Sugammadex is preferred over neostigmine for complete and rapid reversal 1.
• Restore motor capacity before waking the patient 1.

Extubation Criteria

• Patient must be fully awake with return of airway reflexes 1, 2.
• Breathing with good tidal volumes before extubation 1.
• Extubate in sitting position (45-90 degrees) 1.
• Have nasopharyngeal airway available to mitigate partial airway obstruction during emergence 1.

Extubation Plan per Difficult Airway Society Guidelines

• Formal extubation plan must be in place as NAP4 and NAP5 showed high incidence of problems during extubation in obese patients 1.

Post-Operative Care

PACU Monitoring

• Observe unstimulated for minimum 1 hour for signs of hypoventilation, apnea, or hypopnea with oxygen desaturation 1, 2.
• Continuous pulse oximetry monitoring until mobile postoperatively 1, 2.
• Maintain head-up position throughout recovery 1.

Discharge Criteria from PACU

• Routine discharge criteria met 1.
• Respiratory rate normal with no periods of hypopnea or apnea for at least 1 hour 1.
• Oxygen saturation returns to pre-operative values with or without supplementation 1.

Ward Care

• Continue oxygen therapy until baseline saturations achieved 1.
• Implement enhanced recovery protocol with early mobilization - patient should be out of bed day of surgery 1.
• Avoid intramuscular injections due to unpredictable pharmacokinetics in obesity 1.
• Use multimodal analgesia - consider PCA with caution, may require level-2 monitoring if significant sleep-disordered breathing suspected 1.

End-of-Surgery Checklist (Age >75)

• Document core temperature 1.
• Document hemoglobin concentration 1.
• Prescribe age-adjusted and renal function-adjusted analgesia doses 1.
• Prescribe postoperative fluid plan 1.
• Assess if patient can safely return to general ward versus requiring level-2 care 1.

Critical Pitfalls to Avoid

• Do not use standard adult dosing - elderly patients require 30-50% dose reduction of all agents 1.
• Do not extubate in supine position - sitting position is mandatory 1.
• Do not discharge from PACU without adequate observation period - minimum 1 hour unstimulated observation required 1.
• Do not rely on clinical assessment alone for neuromuscular recovery - quantitative monitoring is essential 1.
• Do not underestimate sleep-disordered breathing risk - assume it is present and modify technique accordingly 1, 2.
• Do not forget amlodipine - continue antihypertensive through perioperative period unless specifically contraindicated 1.