A patient with pericardial effusion and an endocrine problem

An elderly man with diabetes and chronic renal failure was diagnosed with a pericardial effusion a few months ago. He underwent pericardial aspiration and analysis of the pericardial fluid at another hospital before coming to us. The cardiologist in that hospital felt that the pericardial effusion was due to his renal failure. This patient presented to us because of a feeling of extreme tiredness and a history of hypoglycemic episodes. We initially attributed his tiredness to his hypoglycemic episodes. He was on oral Glibeclamide for diabetes and we stopped that drug. When his blood reports showed a severe degree of hyponatremia and his physical examination showed pigmentation of the palms, palate and lips, we considered another diagnosis.

Discussion

The pigmentation over the skin and mucosa along with the hyponatremia and hypoglycemia are suggestive of adrenal insufficiency or Addison's disease. Since this patient has chronic renal failure and is on a long acting sulphonylurea - Glibenclamide - the hypoglycemic episodes can also be blamed on the inappropriate use of glibenclamide. The suspicion of Addison's disease can be tested by doing a random plasma cortisol level. If the random plasma cortisol value is more than 25mcg/dL in a patient whose serum albumin is normal, Addison's disease is unlikely. Confirmation of diagnosis of Addison's disease can be done by doing the ACTH stimulation tests to see if the adrenal cortex responds appropriately by producing glucocorticoids and mineralocorticoids to an injection of ACTH. Treatment of Adrenal insufficiency for this patient can be initiated with a higher than usual replacement doses of hydrocortisone (for example, 100mg three times a day for one day followed by 50mg three times a day for one day and tapering thereafter). Maintenance doses of hydrocortisone for Addison's disease is usually between 15 and 20mg per day: a larger portion of hydrocortisone (10 -15mg) is given in the morning and a smaller portion (5 -10mg) is given in the late afternoon. When hydrocortisone is given at night, it may cause insomnia and that is why it is preferable to give the evening dose in the late afternoon. One thing to remember is that the adrenal gland produces both glucocorticoids and mineralocorticoids and replacement for both is needed. However, since hydrocortisone has a slight degree of mineralocorticoid activity, it is not necessary to add a separate mineralocorticoid drug (fludrocortisone) if more than 100mg per day of hydrocortisone is being given. When maintenance doses of hydrocortisone are being used, fludrocortisone is needed.

The following facts are nice to know:

1. Cortisol is the name of the glucocorticoid produced by the adrenal gland. This is the same as hydrocortisone.

2. Cortisone is the inactive form of cortisol. When given as a tablet, it is converted to cortisol in the body.

3. Prednisolone is the active form of prednisone. This is a synthetic glucocorticoid. Prednisolone is preferred over prednisone in patients with liver disease.

4. All glucocorticoid hormones have anti-inflammatory activity. These are graded as:

5mg of prednisolone being equivalent to 20mg of hydrocortisone / 25mg cortisone / 0.75mg dexamethasone /4mg methylprednisolone.