Page 336 - Critical Care Nursing Demystified

Chapter 7 CARE OF THE PATIENT WITH ENDOCRINE DISORDERS 321

Nursing Interventions

Obtain daily weights to determine fluid retention or fluid loss.
Assess urine and blood laboratory values and act upon changes.
Assess skin turgor and signs of tenting.
Monitor fluid intake and urine output; output should exceed intake.

Diabetes Insipidus (DI)

What Went Wrong?
Diabetes insipidus is caused by an underproduction of ADH. It occurs when there
is a deficit or hypofunctioning of ADH, leading to water diuresis and dehydration.
With an absence of ADH, the kidneys cannot reabsorb water or control fluid
output. The body is then deprived of necessary fluid hydration and the kidney
tubules cannot conserve enough water to reduce sodium levels. Hypernatremia
and increases in serum osmolality occur, which stimulate the thirst receptors as
the individual attempts to replace lost bodily fluids and prevent dehydration and
severe hypernatremia. There are three types of diabetes insipidus:
1. Neurogenic or central DI – An interruption in the synthesis and release of Downloaded by [ Faculty of Nursing, Chiangmai University 5.62.158.117] at [07/18/16]. Copyright © McGraw-Hill Global Education Holdings, LLC. Not to be redistributed or modified in any way without permission.
ADH. ADH levels can be low. Causes include
Primary – Abnormalities within the posterior pituitary gland, hypothala-
mus, or the infundibular stalk prevent the release of ADH. The cause can
be sporadic or idiopathic in nature, which means the cause is either un-
known or it has an abrupt onset.
Secondary – Occurs from trauma or a pathologic condition such as benign
or malignant tumors, neurosurgery, radiation, and infections of the poste-
rior pituitary gland. Frequently found in patients in critical care units with
head injuries or fluid loss from intracranial surgery.
2. Nephrogenic DI (NDI) – Enough ADH is available, but there is a de-
creased response to circulating ADH by the kidney. The problem can be
drug induced by long-term use of lithium carbonate, which reduces kid-
ney tubule responsiveness to ADH. The ADH level remains normal, the
signs of diabetes insipidus are apparent, serum osmolality is elevated, and
urine output is increased.
3. Dispogenic DI or psychogenic DI – A rare form of overhydration or water
intoxication associated with excessive fluid intake of 5 or more liters per
day. The individual generally favors iced or cold beverages. The ADH level
remains normal but pure water is lost from the kidney leading to hyper-
natremia.