Unmasked renal impairment and prolonged hyperkalemia after unilateral adrenalectomy for primary aldosteronism coexisting with primary hyperparathyroidism: report of a case

Prolonged postoperative hypoaldosteronism related to hyperkalemia in patients with aldosterone-producing adenoma

Hyperkalemia is developed in a part of patients with aldosterone-producing adenoma (APA) after adrenalectomy, suspected to be due to the insufficiency of aldosterone secretion. The purpose of this study is to determine the frequency and characteristics of prolonged postoperative hypoaldosteronism (PPHA) using chemiluminescent enzyme immunoassay (CLEIA). We studied 58 patients with APA with long time after adrenalectomy and whose PAC was measured using a CLEIA kit. The PAC value measured using CLEIA was significantly lower than that of using RIA between two consecutive visits before and after the shift of measuring method of PAC (median [interquantile range], 123.0 [99.8-164.0] vs. 39.5 [15.8-64.2] pg/mL, p < 0.01). PAC was below the minimum limit of quantification (4.0 pg/mL) of the CLEIA kit at least once in nine patients (15.5%) who had PPHA. The PPHA group were older (mean ± standard deviation, 61.3 ± 8.5 vs. 50.5 ± 10.1 years, p < 0.01) and had lower eGFR (60.3 ± 14.0 vs. 82.3 ± 22.8 mL/min/1.73 m2, p < 0.01) than the non-PPHA group. The frequency of postoperative hyperkalemia (maximum serum potassium >5.5 mEq/L) was higher in the PPHA group than in the non-PPHA group (55.6% vs. 8.2%, p < 0.01). In conclusion, a few patients with APA long time after adrenalectomy had unmeasurable PAC using CLEIA. PPHA is likely to develop in patients with APA after adrenalectomy who are older and have impaired renal function. Additionally, PPHA is related to the occurrence of postoperative hyperkalemia.

[Persistent and serious hyperkalemia after surgery of primary aldosteronism: A case report]

Hyperkalemia was one of the complications after primary aldosteronism surgery. Hyperkalemia after primary aldosteronism surgery was uncommon in clinical practice, especially persistent and serious hyperkalemia was rare. This complication was not attached great importance in clinical work. A case about persistent and serious hyperkalemia after primary aldosteronism adrenal adenoma surgery was reported and the patient was followed-up for fourteen months in this study. This patient had a laparoscopic adrenalectomy due to primary aldosteronism. Hyperkalemia was detected one month after surgery of this patient, the highest level of plasma potassium was 7.0 mmol/L. The patient felt skin itchy, nausea, palpitation. Plasma aldosterone concentration fell to 2.12 ng/dL post-operation from 35.69 ng/dL pre-operation, zona glomerulosa insufficiency was confirmed by hormonal tests in this patient after surgery. And levels of 24 hours urinary potassium excretion declined. Decrease of aldosterone levels after surgery might be the cause of hyperkalemia. Hyperkalemia lasted for 14 months after surgery and kalemia-lowering drugs were needed. A systemic search with "primary aldosteronism", "hyperkalemia", "surgical treatment" was performed in PubMed and Wanfang Database for articles published between January 2009 and December 2019. Literature review indicated that the incidence of hyperkalemia after primary aldosteronism surgery was 6% to 29%. Most of them was mild to moderator hyperkalemia (plasma potassium 5.5 to 6.0 mmol/L) and transient. 19% to 33% in hyperkalemia patients was persistent hyperkalemia. Previous studies in the levels of plasma potassium reached the level as high as 7 mmol/L in our case were rare. Whether hypoaldosteronemia was the cause of hyperkalemia was not consistent in the published studies. Risk factors of hyperkalemia after primary aldosteronism surgery included kidney dysfunction, old age, long duration of hypertention. This paper aimed to improve doctors' aweareness of hyperkalemia complication after primary aldosteronism surgery. Plasma potassium should be monitored closely after primary aldosteronism surgery, especially in the patients with risk factors. Some patients could have persistent and serious hyperkalemia, and need medicine treatment.

Contralateral suppression of aldosterone at adrenal venous sampling predicts hyperkalemia following adrenalectomy for primary aldosteronism

BACKGROUND

We aimed to determine whether a greater degree of contralateral suppression of aldosterone secretion at adrenal venous sampling predicted the development of postoperative hyperkalemia after unilateral adrenalectomy for primary aldosteronism.

METHODS

A retrospective analysis of patients undergoing unilateral adrenalectomy for primary aldosteronism between 2004-2015 was performed. Clinical and biochemical parameters of patients who developed hyperkalemia (≥5.2 mmol/L) after unilateral adreanlectomy were compared with those who remained normokalemic. The contralateral suppression index was defined as the aldosterone-to-cortisol ratio from the nondominant adrenal vein divided by the aldosterone-to-cortisol ratio from the external iliac vein.

RESULTS

Of 192 patients who met criteria for inclusion, 12 (6.3%) developed hyperkalemia (median serum potassium 5.5 mmol/L, range 5.2-6.2 mmol/L), with a median time to onset of 13.5 days (range 7-55 days). Five patients had transiently increased serum potassium concentrations that normalized spontaneously. Four patients received mineralocorticoid replacement therapy with fludrocortisone. On univariate analysis, hyperkalemic patients had slightly greater preoperative serum creatinine levels (1.2 vs 1.0 mg/dL, P = .01), higher postoperative creatinine (1.3 vs 1.0 mg/dL, P = .02), lesser median contralateral suppression index (0.14 vs 0.27, P = .03), and larger adenomas (1.9 vs 1.4 cm, P = .02). On multivariable logistic regression, the contralateral suppression index remained the only significant predictor of postoperative hyperkalemia (P = .04) with an optimal cut-off of <0.47.

CONCLUSION

Hyperkalemia after unilateral adrenalectomy for primary aldosteronism is uncommon and usually transient, but may require mineralocorticoid supplementation. Patients with a contralateral suppression index of <0.47 require meticulous follow-up and monitoring of serum potassium concentrations after unilateral adrenalectomy.