<s>[INST] context: Choice of glucocorticoid in patient with acute adrenal insufficiency

In a patient without a previous diagnosis of adrenal insufficiency.

- Dexamethasone 4 mg i.v. is preferred because in contrast to hydrocortisone it is not measured in serum
cortisol assays so it does not interfere with the measurement.

For patients with known diagnosis of adrenal insufficiency.

- Dexamethasone, i.v. hydrocortisone or any intravenous glucocorticoid preparation may be used.

This can rapidly decrease the inappropriate vasopressin production with increased clearance of free water and correction of hyponatremia.
In contrast to glucocorticoid replacement, mineralocorticoid replacement is not necessary acutely because it takes several days for its sodium retaining effects to appear and adequate sodium replacement can be achieved by intravenous saline alone.
However in patients with known primary adrenal insufficiency with potassium > 6.0 meq./L hydrocortisone is preferred because of its mineralocorticoid activity.

Treatment of acute adrenal insufficiency (adrenal crisis) in adults
Emergency measures

Establish intravenous access with a large-gauge needle.
Draw blood for immediate serum electrolytes and glucose and routine measurement of plasma cortisol and ACTH. Do not wait for lab results.
Infuse 2 to 3 liters of isotonic saline or 5 percent dextrose in isotonic saline as quickly as possible. Frequent hemodynamic monitoring and measurement of serum electrolytes should be performed to avoid iatrogenic fluid overload.
Give 4 mg dexamethasone as intravenous bolus over one to five minutes and every 12 hours thereafter. Dexamethasone is the drug of choice because it does not interfere with the measurement of plasma cortisol. If dexamethasone is unavailable, intravenous hydrocortisone, 100 mg immediately and every six hours thereafter, may be used.
Use supportive measures as needed.

Subacute measures after stabilization of the patient

Continue intravenous isotonic saline at a slower rate for next 24 to 48 hours.
Search for and treat possible infections precipitating causes of the adrenal crisis.
Perform short ACTH stimulation test to confirm the diagnosis of adrenal insufficiency, if patient does not have know adrenal insufficiency.
Determine the type of adrenal insufficiency and its cause if not already known.
Taper parenteral glucocorticoid over one to three days, if precipitating or complicating illness permits, to oral glucocorticoid maintenance dose.
Begin meneralocorticoid replacement with fludrocortisone, 0.1 mg by mouth daily, when saline infusion is stopped.

 
Pheochromocytoma [/INST] question: DOC in adrenal insufficiency?a) Hydrocortisoneb) Adrenalinec) Dexamethasoned) Fludrocortisone | options: A: a B: bc C: ad D: ac | answer: D </s>