Laparoscopic Adrenalectomy After Ten Days of Phenoxybenzamine
A 44-year-old man with 12 months of paroxysmal headache, sweating and palpitations has a 5 cm right adrenal mass and 24-hour urinary metanephrines six times the upper limit of normal. He has been on phenoxybenzamine 10 mg twice daily for 10 days, plus amlodipine 5 mg. In clinic his blood pressure is 138/86 mmHg seated with a heart rate of 96, and 108/64 mmHg standing with a heart rate of 120; he reports mild postural dizziness but no syncope. Haematocrit 0.35, sodium 137 mmol/L, potassium 3.4 mmol/L, glucose 8.1 mmol/L. The ECG shows left ventricular hypertrophy with strain and occasional ventricular ectopics; echocardiography shows mild LVH with an ejection fraction of 55%. Laparoscopic right adrenalectomy is scheduled tomorrow morning. He weighs 92 kg, has a BMI of 31 and no other comorbidity, and the surgeon plans carbon dioxide insufflation to 14 mmHg.
1. Is he adequately prepared for surgery? What would you change, and what would you use as the endpoints of adequate alpha blockade?
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He is only partially prepared, and proceeding tomorrow carries real risk.
Endpoints of adequate alpha blockade: seated blood pressure below 130/80 mmHg, standing systolic pressure of at least 90 mmHg with a postural drop but no syncope, symptom relief, no ECG strain changes or significant arrhythmia, and a haematocrit below about 45% (reflecting volume re-expansion). He meets the postural criterion only partially, has a standing heart rate of 120, persistent LVH with strain and ventricular ectopics on the ECG, and is still on a very low phenoxybenzamine dose (20 mg/day for a 92 kg man, versus a typical requirement of about 1 mg/kg/day).
What I would change:
- Increase phenoxybenzamine to 20 mg twice daily or more, titrated over a further 7–14 days, with a high-salt diet (over 5 g/day) and 2 L of oral or intravenous fluid daily to re-expand the contracted intravascular volume.
- Beta blockade only after adequate alpha blockade, at a low dose such as metoprolol 25 mg twice daily, for reflex tachycardia (heart rate 96 seated and 120 standing). Given before alpha blockade, it causes unopposed alpha-mediated vasoconstriction, hypertensive crisis and pulmonary oedema.
- Correct potassium to around 4 mmol/L and recheck glucose; both are driven by catecholamine excess and will change abruptly after resection.
- Aspirin and other drugs reviewed, VTE prophylaxis, and a further cardiology review of the ECG changes.
My judgement would be to delay surgery by 1–2 weeks and intensify blockade rather than proceed tomorrow, unless the surgical team and endocrinologists agree the tumour is rapidly progressive.
2. Describe your intraoperative plan: monitoring, choice and avoidance of drugs, and management of both the hypertensive crisis on tumour handling and the hypotension after venous ligation.
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Monitoring and preparation:
- Arterial line sited awake, before induction; large-bore peripheral access; central line and urine output; temperature; hourly (then half-hourly) blood glucose; consider transoesophageal echocardiography if there is cardiac dysfunction or major fluid shifts. Benzodiazepine premedication to blunt sympathetic surges.
- Drugs to avoid: ketamine, ephedrine, droperidol, metoclopramide, atropine, morphine and atracurium (histamine release), and desflurane for its sympathetic stimulation. Succinylcholine is best avoided because of fasciculations.
- Induction: propofol, remifentanil and rocuronium, with adequate depth before laryngoscopy, plus lidocaine 1.5 mg/kg, esmolol 0.5–1 mg/kg and magnesium 2 g to blunt the pressor response.
Hypertensive crisis on tumour handling: first deepen anaesthesia and increase remifentanil; then phentolamine 1–5 mg boluses, or sodium nitroprusside 0.5–5 micrograms/kg/min, or nicardipine/clevidipine infusions. Magnesium infusion 1–2 g/h is a useful adjunct. Tachycardia is treated with esmolol 10–50 mg boluses, avoiding large beta-blockade in a catecholamine-loaded ventricle.
Hypotension after venous ligation: anticipate it, give 500–1000 mL crystalloid or colloid, stop all vasodilators, reduce volatile concentration (catecholamine levels fall abruptly; keep the patient asleep with remifentanil and propofol), and start noradrenaline 0.05–0.2 micrograms/kg/min or vasopressin 0.5–2 units/h. Check glucose every 30 minutes; hypoglycaemia can occur within an hour. Give hydrocortisone 100 mg if the adrenal cortex has been resected or the patient remains refractory to vasopressors. Pneumoperitoneum at 14 cmH2O reduces venous return, so release it if hypotension is severe.
3. Where would you recover this patient, when would you extubate, and which specific postoperative complications would you actively look for?
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Disposition: I would plan for invasive monitoring and ICU or high-dependency care for at least 24 hours. The indications here are intraoperative haemodynamic lability, a catecholamine-secreting tumour with abrupt haemodynamic swings, a moderately dilated LV with LVH and ectopy, and the possibility of significant blood loss from the adrenal bed.
Extubation: at the end of surgery if he is warm, haemodynamically stable on minimal or no vasopressor, with adequate respiratory effort and gas exchange and a controlled blood pressure. If he has needed large fluid volumes, high-dose vasopressors or has ongoing bleeding, keep him sedated and ventilated overnight.
Complications to look for:
- Hypoglycaemia from rebound hyperinsulinaemia after catecholamine withdrawal - check glucose every 30–60 minutes for the first 4–6 hours, then hourly for 24 hours.
- Adrenal insufficiency if the whole gland was resected or the contralateral gland is suppressed: unexplained hypotension, hyponatraemia, hyperkalaemia, hypoglycaemia - check a morning cortisol and treat empirically with hydrocortisone.
- Bleeding into the retroperitoneum - a falling haemoglobin and rising vasopressor requirement.
- Haemodynamic instability in either direction; treat hypertension with a short-acting agent and hypotension with fluids and noradrenaline.
- Respiratory complications of laparoscopy: atelectasis, pneumothorax, carbon dioxide embolism, and shoulder-tip pain.
- Pancreatic injury or pancreatitis after right adrenalectomy - check amylase and lipase if there is epigastric pain; ileus; wound infection. Follow-up: repeat metanephrines at 2–4 weeks, lifelong surveillance for recurrence, and genetic testing for hereditary phaeochromocytoma syndromes (about 10–15% of cases), including MEN2, VHL and SDH mutations.