Regional anesthesia for arthroscopic knee repair in patient with HOCM under monitored anesthesia care with dexmedetomidine: A Case Report

Julie J. Cunningham¹, Andrew S. Braun², Promil Kukreja²

¹ Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
² Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, USA

Background
Hypertrophic Obstructive Cardiomyopathy (HOCM):
• Most common inherited cardiac malformation (1/500 adults).¹
• Perioperative goals: maintain volume status, systemic vascular resistance, avoid tachycardia, reduce contractility, and select agents with minimal sympathetic effects.¹
Regional Anesthesia (RA):
• Minimizes hemodynamic fluctuations, avoids intubation, reduces pharmacologic side effects, enhances recovery after surgery, and greater patient satisfaction.²
Dexmedetomidine (DEX):
• Highly selective alpha-2 adrenergic agonist
• Indirect and direct cardioprotective effects, minimal respiratory depression, reduced sympathetic response, anxiolysis, sedation, and analgesia.^3,4

Case Description
• 15-year-old female with HOCM, mild cognitive delay, seasonal asthma, and obesity came to UAB for a right knee arthroscopy for patellar instability
• Prior echo: moderately hypertrophic and hyperdynamic LV (EF >65%), mild MV systolic anterior motion, and mild MV chordal abnormality with LV outlet obstruction.
• Preoperative TTE POCUS was performed (Fig. 1)
• Peripheral nerve blocks with ropivacaine:
    • Right femoral nerve block (20 mL, 0.5%)
    • Right fascia iliaca nerve block (20 mL, 0.2%)
• Surgical time: 166 min

Outcome
• Procedure tolerated without hemodynamic compromise and no intraoperative opioid use.
• PACU: no postoperative pain, opiates, or PONV.

Discussion
• HOCM presents challenges for anesthesiologists due to the potential for hemodynamic instability and cardiac arrhythmias.
• Anesthesiologists should recognize that regional and neuraxial techniques offer practical alternatives to general anesthesia, especially for patients with advanced diseases or critical conditions.