Severe Aortic Stenosis and a Hip Fracture: Choosing and Rescuing the Anesthetic
78-year-old woman with severe aortic stenosis (aortic valve area 0.8 cm2, mean gradient 44 mmHg, EF 55%, dyspnea climbing one flight) falls at home and sustains a displaced femoral neck fracture. Surgery is booked for the next morning. Medications: metoprolol 25 mg daily, aspirin 81 mg, atorvastatin. BP 136/70 mmHg, HR 58, SpO2 96% on room air. She is anxious and mildly confused after morphine given in the emergency department. The orthopedic surgeon prefers general anesthesia for speed; the ward team asks you to just do a spinal.
1. Choose an anesthetic technique and defend it, including what you would refuse to compromise on.
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The honest answer. Trial data show no meaningful mortality difference between spinal and general anesthesia for hip fracture; the outcome is driven by hemodynamic control, analgesia, and time to surgery, not by the technique label. So either is defensible - and that is exactly the reasoning to give.
Physiology that constrains both. Severe AS means fixed stroke volume; cardiac output is preload- and rate-dependent, coronary perfusion depends on diastolic pressure, and tachycardia is poorly tolerated. Goals: sinus rhythm, HR 60–80, adequate preload, MAP near baseline, no drop in SVR.
Case for low-dose spinal. Avoids airway manipulation in a possibly full stomach with post-morphine confusion, provides dense analgesia. But sympathectomy drops SVR, and with a fixed orifice that means hypotension. If chosen: small incremental dose (e.g., 7.5 mg bupivacaine), no high block, vasopressor drawn up before the needle, fluid preload modest because she is preload-dependent but also at risk of pulmonary edema.
Case for general. Full control of rate and afterload, controlled ventilation, airway protection given the altered mental status. Costs: induction hypotension with propofol, blunted sympathetic response.
Non-negotiables. A fascia iliaca block for analgesia regardless of technique; arterial line for beat-to-beat pressure; phenylephrine immediately available; surgery tomorrow rather than delayed for cardiac workup. Declining the case or the block because of the valve would be the wrong call.
2. Ten minutes after a low-dose spinal, BP is 76/38 with HR 52. Walk through your management and the reasoning behind each step.
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Interpretation. Sympathectomy has dropped SVR; with a fixed stenotic orifice, stroke volume cannot rise to compensate, and the bradycardia further reduces output. Coronary perfusion pressure is now critically low in a hypertrophied ventricle - this is the dangerous scenario, treat it fast.
Stepwise management
- Phenylephrine 50–100 mcg boluses, repeated and titrated to MAP. It restores SVR without adding chronotropy, which is what you want first.
- Left uterine-type displacement / leg elevation only if tolerated; a small 250 mL crystalloid bolus, but stop early - over-resuscitation in severe AS causes pulmonary edema.
- If bradycardia persists below 50 with hypotension, phenylephrine alone will not help because output is rate-limited. Add ephedrine 5–10 mg or glycopyrrolate 0.2 mg to restore a sinus rate of 60–70.
- Avoid tachycardia deliberately - do not overshoot with ephedrine; a rate of 110 in severe AS causes ischemia and a fall in output.
- Escalate if refractory: stop surgery, convert to general anesthesia with careful induction, consider a low-dose epinephrine infusion, and call for help.
What not to do. Neuraxial opioid top-ups or a fluid bolus alone; both miss the mechanism and delay definitive treatment of a falling coronary perfusion pressure.
3. The ward team proposes delaying three days for cardiology consultation and possible valve intervention. How do you respond?
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Frame the competing harms. Hip fracture mortality rises with delay beyond about 48 hours - immobility, delirium, pneumonia, thromboembolism, pressure injury. Against that, an unoperated severe AS carries perioperative risk, but the risk is modifiable with hemodynamic management, not removable within days.
What would actually change management? Neither TAVR nor surgical valve replacement can be delivered inside the fracture window, and a patient with dyspnea only on stairs and no rest symptoms does not have an emergent valve indication. Cardiology input is useful for risk discussion and for planning definitive valve therapy after recovery, but it should run in parallel, not ahead of surgery.
What would justify delay. Active decompensation: resting ischemia, pulmonary edema, syncope, new arrhythmia, or an uncontrolled infection at the surgical site. None are present here.
Practical answer. Proceed tomorrow with an arterial line, a plan for tight rate and afterload control, regional analgesia for the fracture, and a documented note stating that cardiology has been consulted for postoperative planning. Ask the cardiologist for a same-day curbside opinion or phone discussion instead of a formal consult that pushes the case. This is a system-level judgment call, not a knowledge recall item, and it should be documented with reasoning.