Investigation for primary hyperaldosteronism and concurrent post partum thyroiditis whilst continuing to breast feed (BF) is difficult and challenging for both the woman and the clinical team.
A 28 year old woman presented with palpitations, headache, BP 190/110 mmHg, p 120. No history of hypertension, normal to low BP in recent pregnancy, currently BF 4 month old child.
Lab results- hypokalaemia 2.4mmol/L (n 3.5-5.0 mmol/L), suppressed TSH <0.01 mIU/L, freeT4 28.9
pmol/L (n 9.0-22.0 pmol/L), fT3 10.8 pmol/L (n 2.5-6.5pmol/L). Initial care focused on normalizing K+ with supplements and treating hypertension. Potassium requirements were significant, titrated up to 14 supplements daily. A calcium channel blocker (verapamil) was a safe antihypertensive for use in lactation but also allowed ongoing assessment and interpretation plasma aldosterone. The aldosterone level was 1084 pmol/L (n 80-1040 pmol/L) with suppressed renin <40fmol/L. TFT’s normalised without treatment.
The Endocrine Clinical Nurse Consultant’s (CNC) role throughout the following months included
explanation, education, psychological support and the diagnostic testing. A saline load test (SLT) was performed. A potassium infusion was required to treat progressive hypokalaemia over the 4 hour test. In the presence of undetectable plasma renin, the aldosterone level was not suppressed, only decreasing from 1067 to 700 pmol/L at the end of the SLT (n < 135pmol/L). A non contrast CT scan was performed allowing BF to continue. It showed 2 cm adenoma of the right adrenal.
Adrenal vein sampling (AVS) was coordinated by the CNC. This involves an iodine load which potentially raises breast milk iodine content. Infant exposure to high iodine levels could cause transient hypothyroidism therefore expressed breast milk was analysed daily for iodine content before BF could recommence. AVS confirmed an aldosterone producing adenoma with levels of >800,000pmol/L from the right adrenal. The patient proceeded to successful right adrenalectomy with rapid improvement in K+ and cessation of all medications.
This case required continual reflection on how every test or treatment may impact on the breast milk
quality and quantity, as well as maternal and infant well being. The CNC was closely involved in timing of diagnostic tests and radiological scans. Continual monitoring of medical therapy was required to ensure that BF could be continued for as long as possible without compromising the woman’s clinical condition.