Journal of Research and Innovation in Anesthesia
Volume 7 | Issue 1 | Year 2022

Anesthesia Considerations of a Case of Conn Syndrome

Pallavi A Kharat1, Naina P Dalvi2, Tejaswini Bagde3, Madhur M Chole4

1-4Department of Anaesthesiology, HBT Medical College and Dr. R. N. Cooper Hospital, Mumbai, Maharashtra, India

Corresponding Author: Pallavi A Kharat, Department of Anaesthesiology, HBT Medical College and Dr. R. N. Cooper Hospital, Mumbai, Maharashtra, India, Phone: +91 9819689428, e-mail:


Conn’s syndrome is caused due to increased secretion of aldosterone from the adrenal glands. It could be because of an adrenal adenoma or adrenal hyperplasia. Excessive aldosterone levels lead to water retention, hypertension, and hypokalemia. We hereby report a case of a 37-year-old female who presented to the emergency department with quadriparesis and malignant hypertension. On investigating, she was found to have hypokalemia, metabolic alkalosis, rhabdomyolysis, raised aldosterone levels, and a right adrenal adenoma in the CT abdomen. Hypokalemia was treated and she was started on tablet spironolactone. She underwent laparoscopic adrenalectomy under general anesthesia. Her perioperative course was uneventful. Anesthesia management of a case of Conn’s syndrome presents various challenges for the anesthesiologist. Good coordination between anesthesiologists, endocrinologists, and surgeons is required for the successful management of such a case.

How to cite this article: Kharat PA, Dalvi NP, Bagde T, et al. Anesthesia Considerations of a Case of Conn Syndrome. J Res and Innov Anesth 2022;7(1):22-24.

Source of support: Nil

Conflict of interest: None

Keywords: Conn syndrome, Hyperaldosteronism, Hypertension, Hypokalemia, Spironolactone


Adrenal adenomas (Fig. 1) and adrenal hyperplasia are the common cause of primary hyperaldosteronism or Conn’s syndrome. It is commonly seen in females (F:M = 2.5:1) between the age-group of 30-50 years of age and rarely seen in children.1 It may be associated with pheochromocytoma, primary hyperparathyroidism, or acromegaly.2 The incidence of primary hyperaldosteronism in patients is 0.5-1%.3,4 It is the most treatable cause of hypertension. These patients usually present with generalized weakness, fatigue, muscle cramps, and hypertension. These manifestations are due to excessive secretion of aldosterone hormone from the cortex of the adrenal gland. Some patients can have incidental diagnoses of adrenal adenomas which are asymptomatic and are then called incidentalomas.1 Hyperaldosteronism leads to sodium and water retention which causes resistant hypertension and decreased levels of renin. Increased sodium absorption causes potassium loss through urine and metabolic alkalosis.

Fig. 1: Adrenal adenoma

These patients develop muscle cramps and weakness secondary to severe hypokalemia. Hypokalemia needs to be treated vigorously by either intravenous or oral supplementation depending on the serum potassium levels. Also, hypertension is resistant to treatment and hydration with fluids. These patients are started on tablet spironolactone for hypertension and to avoid hypokalemia.

Anesthesia management of these patients involves preoperative optimization of blood pressure and serum potassium levels. Anesthesiologists have to be ready to deal with the sudden rise in blood pressure during handling of the adrenal glands. A laparoscopic approach is ideal for the removal of the adrenal gland as it reduces postoperative cardiorespiratory complications and helps in early ambulation and faster recovery. The serum electrolytes levels are monitored and spironolactone supplementation is stopped in the postoperative period.


We report a case of a 37-year-old female patient who presented with a complaint of pain in both lower limbs for 7 days followed by weakness of all four limbs for 2 days. She was unable to get up from bed and unable to move her upper limbs. She was taken to a tertiary care center where she was found to have a high blood pressure of 210/110 mm Hg and serum potassium level of 1.8 mEq/L, serum magnesium was 2.0 mEq/L, CRP was 12, CPK was 4091 and ABG had metabolic alkalosis pH 7.5, PO2 285, PO2 36, HCO3 28.1. She was treated with intravenous and oral potassium and tablet spironolactone 25 mg bd. Her weakness improved within 24 hours and could walk after 2 days. Her CT abdomen was done which showed a focal lesion in the posterior limb of the right adrenal gland. Renal angiography was normal. Adrenal MRI showed 16 x 14 mm mass attached to medial limb posteriorly with no fat content and no calcification suggestive of a right adrenal adenoma. Her 2DECHO was normal. She had no history of weight gain, no history of similar episodes of weakness in the past, and no history of hirsutism. Endocrinology opinion was taken and found to have DHEA (dehydroepiandrosterone) levels of 30 ng/mL, serum cortisol was 6.03, ACTH (adrenocorticotropic hormone) level was 34.4, and aldosterone levels were 25 ng/dL on treatment with spironolactone. Tablet spironolactone was stopped for 8 days and her DHEA levels were 1.41 ng/mL and aldosterone levels were 22 ng/dL which showed a significant drop. Also, the dexamethasone suppression test was done preoperatively by giving injection dexamethasone 1 mg intravenous at 11 pm and serum cortisol levels were measured a day prior and on the next day at 8 am in the morning. Serum cortisol was 8.2 ugm/dL earlier and to 0.61 ugm/dL in the morning sample. Thus, confirming the diagnosis of hyperaldosteronism. She was planned for laparoscopic right adrenalectomy. The patient was on tab spironolactone 25 mg OD and syrup kesol 1 tablespoon tds. All her routine investigations, serum potassium, ECG, and X-ray chest were within normal limits. The patient was asked to take the morning dose of the tab. spironolactone with sips of water. General anesthesia was decided in view of laparoscopic surgery. The patient was taken to operation theater and a large bore18 G intravenous catheter was secured on left forearm. All standard monitors like ECG, pulse oximeter, non-invasive blood pressure (NIBP), and bispectral index (BIS) were applied. The patient was premedicated with injection glycopyrrolate 0.2 mg, injection midazolam 1 mg, and injection buprenorphine 120 ugms. Anesthesia was induced with injection propofol 100 mgs and injection vecuronium 6 mgs iv. The patient was intubated with 7.0 mm cuffed endotracheal tube and anesthesia was maintained with oxygen: air 50:50, desflurane, and injection vecuronium. The right internal jugular vein was cannulated after induction and her CVP was 6 cm of H2O. The patient was given a left lateral position with a kidney bridge. The patient remained hemodynamically stable throughout the surgery. Total blood loss was around 100 mL and urine output was 700 mL. The surgery lasted for 2 hours and was uneventful. The patient has reversed with injection neostigmine 2.5 mg and injection glycopyrrolate 0.4 mg and was extubated on the table and shifted to anesthesia ICU (AICU) for observation.


Conn’s syndrome is named after Jerome W. Conn (1907-1994), an American endocrinologist, who first described the condition at the University of Michigan in 1955.5 The primary form (Conn’s syndrome) presents the excess of aldosterone due to an adrenal gland disease. A unilateral adenoma is found in the majority (60%) of cases, whereas bilateral adrenal hyperplasia is seen in 30% of cases. It is more common in females than males.6 The adrenal adenoma leads to excessive secretion of aldosterone which causes sodium and water retention, resistant hypertension, and hypokalemia.7 Hypokalemia can present with muscle cramps, weakness, and even paresis of limbs. Hypokalemia if severe can also lead to cardiac arrhythmias which can be fatal.8

The preoperative optimization of patients with Conn’s syndrome involves treatment of hypokalemia and hypertension. Hypokalemia and associated metabolic alkalosis cause prolongation of the action of nondepolarizing muscle relaxants. Also, hypokalemia depresses the baroreceptor tone, so needs to be treated aggressively.8 Hypokalemia is worsened by hyperventilation and so it must be avoided and also sevoflurane.6 Hypertension is mostly the presenting sign in patients with Conn syndrome. Malignant hypertension is known to occur because of increased intracellular volume. The cause is either central or due to aldosterone-induced vasoconstriction.9 These patients are found to have resistant hypertension for which they are usually started on potassium-sparing diuretic like spironolactone on a dose of 100-400 mg/day or amiloride in a dose of 5-15 mg/day. Calcium channel blockers like nifedipine (30-90 mg/day) or ACE inhibitors (captopril) and angiotensin inhibitors (losartan) are also used to treat hypertension.10,11 These patients may either be on a single antihypertensive or a combination of these drugs. A hypertensive emergency can also present with cerebrovascular manifestations like an ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage, transient ischemic attack,12 seizures and coma,13 and cardiac complications like a congestive cardiac failure.

Open or laparoscopic adrenalectomy is performed in patient with Conn’s syndrome. The laparoscopic approach is preferred as it improves the recovery, has minimal postoperative pain and early discharge. Either unilateral or bilateral adrenalectomy is done depending on the involvement of the adrenal glands. Hemodynamic fluctuations are expected at the time of manipulation of adrenal glands during surgery. They can present with sudden hypertension and tachycardia secondary to the release of catecholamines into the circulation from the adrenal gland. Intraoperative short or intermediate-acting muscle relaxants are preferred like atracurium or cisatracurium. Also, sevoflurane is avoided as it is found to prolong the duration of muscle relaxants. The preoperative fluid status is assessed on the basis of the presence of orthostatism, tachycardia, hypotension, and increased hematocrit.14 Hypovolemia is rare and can be multifactorial due to the use of diuretics, anesthetic drugs, positive pressure ventilation, laparoscopic approach, and the patient’s position. Both hypervolemia and hypovolemia must be aggressively treated. The patients in whom bilateral adrenalectomy is done are supplemented with injection hydrocortisone postoperatively.

In our case, the adenoma was removed laparoscopically. She had no hemodynamic fluctuations and the surgery and anesthesia course was uneventful. Ringer lactate was used as a maintenance fluid. The patient was extubated and shifted to the anesthesia ICU for observation. Postoperatively she was not supplemented with steroids. Her serum electrolytes were normal in the postoperative period. She maintained normal blood pressure and tablet spironolactone was stopped after surgery. Her DHEA levels were sent on 5th postoperative day which was normal and she was discharged.


We conclude that anesthesia management of Conn syndrome poses various perioperative challenges involving the treatment of hypokalemia and resistant hypertension. Proper preoperative hormonal evaluation, optimization and good collaboration with endocrinologists, radiologists, surgeons, and anesthesiologists are required for the successful management of such cases.


1. Williams GH, Dluhy RG. Disorders of the adrenal cortex. In: Fauci AS, Braunwald E, Isselbacher KJ, editors. Harrison’s Principles of Internal Medicine. 17th edition. Chapter 336, page 2259-2260. New York, NY, USA: McGraw-Hill Professional Publishing.

2. Stoelting RK, Stephen F, Dierdorf. Endocrine Diseases In: StoeltingAnesthesia and CoExisting Disease, Fourth Edition, Chapter 22, page 429. Elsevier Churchill Livingstone Publishing.

3. Michael FR, Fleisher LA. Anesthetic Implications of Concurrent Diseases. In: Miller’s Anesthesia, Sixth Edition, Chapter 27, page 1038. Elsevier Churchill Livingstone Publishing.

4. Mattsson C Young WF Jr. Primary aldosteronism: diagnostic and treatment strategies. Nat Clin Pract Nephrol 2006;2(04):198-208. DOI: 10.1038/ncpneph0151

5. Conn JW Louis LH. Primary aldosteronism: a new clinical entity. Ann Intern Med 1956;44(01):1-15. DOI: 10.7326/0003-4819-44-1-1

6. Domi R Sula H Kci M Paparisto S, et al. Anaesthetic considerations on adrenal gland surgery. J Clin Med Res 2015;7(01):1-7. DOI: 10.14740/jocmr1960w

7. Born-Frontsberg E Reincke M Rump LC et al. Cardiovascular and cerebrovascular comorbidities of hypokalemic and normokalemic primary aldosteronism: results of the German Conn’s Registry. J Clin Endocrinol Metab 2009;94(04):1125-1130. DOI: 10.1210/jc.2008-2116

8. Harde M Gyanesh P Tiwatane S, et al. Peri-operative management of Conn’s syndrome - a case report. The Internet Journal of Anesthesiology 2008;19:2.

9. Davies M, Hardman J. Anaesthesia and adrenocortical disease. Continuing Education in Anaesthesia, Critical Care & Pain. 2005;Volume 5,Number 4:122-126.

10. Harde M, Gyanesh P, Tiwatane S, et al. Peri-operative management of Conn’s syndrome - a case report. The Internet Journal of Anesthesiology. 2008Volume 19Number 2.

11. Gockel I Heintz A Kentner R et al. Changing pattern of the intraoperative blood pressure during endoscopic adrenalectomy in patients with Conn’s syndrome. Surg Endosc 2005;19(11):1491-1497. DOI: 10.1007/s00464-004-2286-0

12. Miyaji Y Kawabata Y Joki H et al. Primary aldosteronism in patients with acute stroke: prevalence and diagnosis during initial hospitalization. BMC Neurol 2016;16:177. DOI: 10.1186/s12883-016-0701-5

13. Alseddeeqi E Altinoz A Ghashir NB. Seizure and coma secondary to Conn’s syndrome: a case report. J Med Case Rep 2020;14(01):100. DOI: 10.1186/s13256-020-02434-5

14. Jano A Domi R Berdica L et al. Anaesthetic considerations of Conn syndrome: a case presentation and mini-review the anaesthesiologist and Conn syndrome. Clin Med Res 2014;3(05):132-135. DOI: 10.11648/J.CMR.20140305.14

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