What is the recommended general anesthesia plan for a 61-year-old male with Hypertension (HTN), Obstructive Sleep Apnea (OSA), and obesity undergoing knee irrigation and debridement?

General Anesthesia Plan for 61-Year-Old Male with HTN, OSA, and Obesity Undergoing Knee Irrigation and Debridement

For this patient with hypertension, OSA, and obesity undergoing knee irrigation and debridement, regional anesthesia (spinal) with minimal sedation is preferred over general anesthesia due to reduced airway complications, better postoperative pain control, and reduced need for opioids. 1 However, if general anesthesia is required, the following plan should be implemented:

Preoperative Assessment and Preparation

• Assess airway thoroughly (neck circumference, Mallampati score) as obesity increases difficult intubation risk by 30% 2
• Continue CPAP therapy until time of surgery 1
• Consider antacid premedication due to increased aspiration risk 2
• Ensure CPAP device is available for immediate postoperative use 1
• Verify appropriate-sized equipment (operating table, BP cuffs, extra-long airway equipment) 2
• Secure two IV access sites due to potentially difficult vascular access 1

Induction Plan

• Position patient in ramped position with tragus of ear level with sternum 1
• Preoxygenate with 100% O₂ for 3-5 minutes with PEEP 8-10 cmH₂O 1
• Slow induction with propofol 20 mg every 10 seconds (approximately 0.5-1.5 mg/kg) 3
• Avoid rapid bolus induction to prevent cardiorespiratory depression 3
• Use rocuronium 0.6-0.7 mg/kg with sugammadex immediately available 1
• Secure airway with video laryngoscope and ETT 1

Maintenance Plan

• Use pressure-controlled ventilation with:
  • Tidal volume 6-8 mL/kg ideal body weight
  • PEEP 8-10 cmH₂O
  • Periodic recruitment maneuvers 1
• Maintain anesthesia with:
  • Desflurane or sevoflurane (preferable to isoflurane due to faster offset in obese patients) 1
  • Propofol infusion at 100-200 mcg/kg/min 3
  • Opioid analgesia (reduced doses)
• Maintain MAP within 20% of baseline 1
  • Treat hypotension with phenylephrine or norepinephrine infusion
  • Treat hypertension by deepening anesthesia or labetalol IV boluses

Emergence Plan

• Ensure full reversal of neuromuscular blockade with sugammadex 2-4 mg/kg guided by TOF monitoring 1
• Extubate when fully awake with return of airway reflexes in semi-upright position 1
• Apply CPAP as soon as patient can tolerate it 1

Postoperative Management

• Implement multimodal analgesia to minimize opioid use:
  • Acetaminophen
  • NSAIDs (if not contraindicated)
  • Local anesthetic infiltration of surgical site 1
• Provide supplemental oxygen to maintain baseline saturation 1
• Continuous pulse oximetry monitoring for at least 3 hours in PACU 1
• Position patient semi-upright or lateral to minimize airway obstruction 1
• Early mobilization to reduce VTE risk 1
• VTE prophylaxis with LMWH and compression stockings 1

Special Considerations

• Anticipate reduced safe apnoea time due to obesity and OSA 2
• Consider level-2 care if longer-acting opioids are necessary due to risk of developing hypercapnia 2
• Monitor closely for signs of respiratory depression, especially on postoperative days 3-4 1
• Be prepared for potential difficult airway management (have backup devices readily available) 2

Common Pitfalls to Avoid

• Underestimating the degree of airway difficulty in obese patients with OSA
• Inadequate preoxygenation leading to rapid desaturation
• Overreliance on opioids for analgesia, increasing risk of respiratory depression
• Insufficient reversal of neuromuscular blockade before extubation
• Premature discontinuation of monitoring in the postoperative period
• Failure to apply CPAP early in the postoperative period

This anesthesia plan addresses the specific risks associated with this patient's comorbidities while providing adequate anesthesia and analgesia for knee irrigation and debridement.