Fluid & Electrolytes: ADH Disorders

Flashcards covering the concepts of SIADH and Diabetes Insipidus, including pharmacology and physiological effects on blood and urine concentration.

Anti-diuretic hormone (ADH)

Also known as vasopressin (Pitressin), this hormone is found in the pituitary gland and regulates water retention or loss.

SIADH

Syndrome of Inappropriate ADH Secretion, characterized by 'too many letters, too much water,' leading to fluid volume excess, concentrated urine, and diluted blood.

Diabetes Insipidus (DI)

A condition resulting from 'not enough ADH' that causes the body to lose (diurese) water, leading to fluid volume deficit, diluted urine, and concentrated blood.

Vasopressin (Pitressin)

Another name for anti-diuretic hormone (ADH), which can also be utilized as a replacement drug in clinical cases of diabetes insipidus.

Desmopressin acetate (DDAVP)

A drug utilized as an ADH replacement in patients with diabetes insipidus.

Transsphenoidal hypophysectomy

A surgical procedure involving going through the sphenoid sinus to remove the pituitary gland (hypophysis).

Urine in SIADH

Characterized as concentrated, which causes the urine specific gravity, sodium, and hematocrit numbers to go up.

Blood in SIADH

Characterized as diluted because of the retained water, which causes the blood numbers to go down.

Urine in Diabetes Insipidus (DI)

Characterized as diluted because of the excessive output of water (diuresis).

Blood in Diabetes Insipidus (DI)

Characterized as concentrated due to the loss of volume from the body.

Pituitary gland

The location where ADH is found; any injury or surgery to this area can lead to ADH production problems.

Triggers for ADH problems

Conditions such as craniotomy, head injury, sinus surgery, or any condition leading to increased intracranial pressure (ICP).

Diuresis

Increased urine output; in the context of Diabetes Insipidus, this can reach levels such as $3,000\,mL$ and lead to shock.