What is the anaesthetic management of severe aortic stenosis in a patient undergoing short gamma nail for neck of femur (NOF) fracture?

From the Guidelines

The anesthetic management of severe aortic stenosis in a patient undergoing short gamma nail for NOF fracture should ideally involve a carefully titrated neuraxial technique, specifically a continuous spinal anesthesia, to maintain hemodynamic stability while providing adequate anesthesia for the procedure. This approach is supported by the 2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery, which recommends elevated-risk elective noncardiac surgery with appropriate intraoperative and postoperative hemodynamic monitoring in patients with asymptomatic severe aortic stenosis 1.

To achieve this, insert a spinal catheter and administer small incremental doses of local anesthetic (e.g., 0.5-1 ml of 0.5% bupivacaine) to achieve a controlled, limited sensory block to T10 level. Preoperatively, ensure adequate volume status with careful fluid administration and continue all cardiac medications including beta-blockers 1. Intraoperatively, maintain normal sinus rhythm, avoid tachycardia and bradycardia, and preserve systemic vascular resistance.

Key considerations include:

• Use invasive monitoring including arterial line and consider central venous pressure monitoring
• Have vasopressors readily available (phenylephrine 50-100 mcg boluses or norepinephrine infusion 0.01-0.1 mcg/kg/min) to maintain mean arterial pressure within 20% of baseline
• Avoid general anesthesia if possible due to the risks of myocardial depression and vasodilation
• Patients with severe aortic stenosis have fixed cardiac output, rely on adequate preload and afterload, and are extremely sensitive to hemodynamic changes that can precipitate cardiovascular collapse 1.

By following this approach, the risks associated with severe aortic stenosis, such as decreased coronary perfusion pressure, development of arrhythmias or ischemia, myocardial injury, cardiac failure, and death, can be minimized 1.

From the Research

Anaesthetic Management for Severe Aortic Stenosis

The anaesthetic management of severe aortic stenosis in a patient undergoing short gamma nail for neck of femur (NOF) fracture involves careful consideration of the patient's haemodynamic status. Key points to consider include:

• Avoiding hypotension and arrhythmias, as these can increase perioperative morbidity and mortality 2
• Using minimally invasive haemodynamic monitoring to closely monitor the patient's haemodynamic parameters 2
• Considering the use of continuous spinal anaesthesia, which has been shown to be a valid alternative to general or epidural anaesthesia in patients with severe aortic stenosis undergoing lower limb surgery 2
• The use of femoral nerve block with dexmedetomidine, which has been reported to be useful for fracture fixation of an intracapsular fracture of the femoral neck in a patient with severe aortic stenosis 3
• Combined lumbar plexus and sciatic nerve block with mild sedation, which has been used successfully in patients with severe aortic stenosis undergoing femoral neck fracture repair 4

Haemodynamic Considerations

Haemodynamic considerations are crucial in the anaesthetic management of patients with severe aortic stenosis. Key points to consider include:

• The importance of avoiding circulatory disturbance, which can be achieved by using combined lumbar plexus and sciatic nerve block at the injured side 4
• The use of careful monitoring of anesthesia to minimize the risk of perioperative events, such as intraoperative hypotension 5
• The potential benefits of using neuroaxial blockade, which has been reported to improve outcome compared with conventional analgesia 6

Anaesthetic Techniques

Various anaesthetic techniques have been used in patients with severe aortic stenosis undergoing noncardiac surgery. These include:

• Continuous spinal anaesthesia with minimally invasive haemodynamic monitoring 2
• Femoral nerve block with dexmedetomidine 3
• Combined lumbar plexus and sciatic nerve block with mild sedation 4
• General anesthesia, which has been used in some cases, but may carry a higher risk of perioperative complications 5
• Neuroaxial blockade, which has been reported to be a useful alternative to general anaesthesia in patients with aortic stenosis, but requires careful management and monitoring 6