BERKELEY, CA (UroToday.com) - Adrenal gland surgery is a serious issue for a surgical team to deal with. This type of surgery is usually considered when primary or secondary adrenal tumors, incidentalomas, and hormone-secreting adrenal tumors are diagnosed. Non-hormone-secreting adrenal tumors are usually only occasionally diagnosed and have poor clinical presentation; patients are generally referred to a urologist after ultrasound or computerized tomodensitometry examinations. Hormone-secreting adrenal tumors present important challenges to the multidisciplinary team, which is comprised of an endocrinologist, surgeon, anesthesiologist, and intensivist. These types of tumors are often associated with very specific clinical features. It is well known that hypokalemia, hypertension, fatigue, muscle cramps, and persistent untreatable metabolic alkalosis often correlate with Conn’s syndrome. Central obesity, moon face, buffalo hump, thin skin, irregular menstruation, abdominal striaes, hypertension, diabetes, and hypokalemia strongly suggest Cushing’s disease or syndrome. The most aggressive clinical features are caused by pheochromocytomas and include paroxystic severe hypertension, tachycardia, arrhythmias, flashes, and sweating. Patients suffering from hormone-secreting adrenal tumors are usually referred to the surgical team by an endocrinologist after the diagnosis is determined and the patient is well-prepared, preoperatively.
In the perioperative period, the patient undergoing adrenal removal for Conn’s syndrome needs to be placed on spironolactone (a diuretic that posses antialdosterone effects) and must have a medically stable hemodynamic status and a corrected blood potassium level. After the Cushing’ s syndrome has been determined as adrenal gland in origin, based on the endocrinologist’s consult and imaging examinations, the endocrinologist usually begins drugs that inhibit cortisol synthesis, such as ketokonazole, metyrapone, or mitotane. In the perioperative period, the anesthesiologist and endocrinologist closely cooperate to prepare the patient for anesthesia and surgery, correcting diabetes, hypertension, and screening for cardio-pulmonary defects. Due to obesity and hypertension, patients suffering from Cushing syndrome present with restrictive pulmonary disease and various degrees of cardiac impairment function, up to heart failure. Epidural anesthesia and analgesia (as a supplement of general anesthesia), seems to be a suitable anesthetic choice. These issues are important to the anesthesiologist in the intraoperative and postoperative period. Nevertheless Cushing’s syndrome seems to be more benign than pheochromocytoma to the anesthesiologist as pheochromocytoma presents a much greater challenge to the anesthesiologist, and a good preoperative preparation is required to guarantee success. Several authors have recently reported treatment regimens, but we strongly encourage the use of competitive α1-adrenergic receptors blockers (for example doxazosin 2-6 mg daily) to prepare these patients for surgery. A potential advantage of competitive, selective α1-blockade is that, once the tumor has been resected and excess catecholamine release eliminated, α-adrenergic receptors return quickly to normal function, leading to less hypotension. Phenoxybenzamine (a non-selective α-adrenergic receptors blocker) causes a more severe and prolonged hypotension after adrenal gland removal, and is usually stopped 24-48 hours before surgery. Β-adrenergic blockers are used only after the α-adrenergic blockade is effectively instituted. Large-bore peripheral and central venous catheters are required to administer appropriate amounts of liquids and vasoactive drugs. Several drugs (pancuronium, ketamine, and desflurane) that can simulate the sympathetic system -- inducing hypertension, and tachycardia -- are best avoided. In order to ensure a smooth endotracheal intubation without increasing sympathetic tone, the anesthesiologist must ensure adequate anesthesia depth, using vasodilators (nitropruside, nitroglycerine, urapidil, nicardipine), short acting β-blocking drugs (esmolol), magnesium sulfate, and anesthetic drugs (remifentanil and propofol). The combination of propofol and remifentanil, and dexmetedomidine use, are a modern anesthetic regimen treating option in order to provide an adequate depth of anesthesia and blunting of the sympathetic response during intraoperative surgical manipulation. In our institution, we do not encourage chemical block using the epidural route because of unpredictable and often difficult-to-treat hemodynamic effects.
The postoperative period is almost the same for the three types of hormone-secreting adrenal tumors. Postoperative care is focused on hemodynamic and respiratory stability, preventing deep venous thrombosis and stress gastric ulcers, and correcting all acido-basic and electrolytes disturbances. An important issue of postoperative care is the laboratory screening of remaining adrenal gland function, preventing adrenal gland function failure. According to laboratory findings, supplements of exogenous cortisol (hydrocortisone) must be considered.
In our institution, we treated more than 40 cases of hormone-secreting adrenal tumors during a 5-year period. The majority of cases were pheochromocytoma, whereas only 2 cases were with Conn’s syndrome and four cases with Cushing’s syndrome, No deaths were recorded and there was no increased mortality. Despite strict preoperative patient evaluation and optimization, the employment of modern anesthetic techniques, and intraoperative monitoring, we believe that the most important step that can guarantee success is a multidisciplinary team, an attentive anesthesiologist, and a skillful urologist.
Written by:
Rudin Domi, MD, PhD as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
Associated Professor of Anesthesiology, Department of Surgery, Division of Anesthesiology and Intensive Care Medicine, “Mother Teresa” University Hospital Center, Tirana, Albania
Anesthetic considerations on adrenal gland surgery - Abstract