Feb 2, 2009

Caring for patients with Diabetes Insipidus

Diabetes insipidus is a disorder in which there is abnormal urine output which is followed by increased fluid intake and thirst. According to the article, it is a metabolic disorder that occurs when the body can't secrete or utilize antidiuretic hormone (ADH). ADH is synthesized in the hypothalamus and stored in the posterior pituitary. ADH or vasopressin is the hormone responsible for regulating the body's retention of water.It is released when the body becomes dehydrated so the the kidneys could decrease the release of water, thereby decreasing urine output. When Diabetes Insipidus occurs, this mechanism is altered and the body wastes water and urine output increases. The patient may produce 3-15 liters of urine daily. The three hallmark signs of Diabetes Insipidus includes polydipsia, polyuria and dehydration.


Mechanism of ADH and water regulation in the body


The two main types of Diabetes Insipidus- Neurogenic and Nephrogenic. Neurogenic DI occurs when the pituitary cant release ADH when stimulated. This could be due to any trauma or damage to the hypothalamus or posterior pituitary. Intracranial tumor, neurosurgery or cerebral edema are just a few possible causes of this type of prohibited release. The Nephrogenic occurs when there is polycystic disease or pyelonephritis present. These prevents the renal tubules from reabsorbing water in response to antidiuretic hormone.

The patients experiencing DI may crave cold liquids to compensate for the thirst response. Based on fluid loss experienced, patients may be unable to adequately replace that fluid loss which consequently leads to dehydration. Signs exhibited may include dry mucous membranes, dry skin turgor and decreased saliva and sweat production. According to the article hypovolemia, hypotension and electrolyte imbalances may occur evidently. It was also stated that without adequate fluid replacement hyponatremia may affect the patients cerebral function causing decreased level of consciousness or coma.

Diagnosing this illness is mainly done by checking the plasma and urine osmolality . These values would be decreased due to the urine loss.. A fluid deprivation test would also be done to determine the extent of the type of DI, whether it be neurogenic or nephrogenic.

The major role of the nurse in managing this disease process would include:-
  • Assessing patients input and output records to ensure adequate fluids replacement and balance, giving oral and intravenous fluids as prescribed.

  • Assess the patient's vital signs to note any changes that may require medical intervention. Note the patient's heart rate and blood pressure. Hypotension may be indicative of hypovolemia and hypertension may indicate water intoxication.Instill hydrostatic hypotension precautions and teachings.

  • Monitor fluid and electrolyte status.

  • Monitor patient's level of consciousness, changes in behavior, mood and anxiety level. This may be indicative of altered cerebral function.

  • Weigh patient daily, at the same time each morning with the same clothes.

  • Administer prescribed ADH therapy, monitoring for signs of toxicity, and signs that require visit to the physician.

  • Teach patients about the disease process and its management.

  • Provide an environment that encourages clarification of any questions the patient may have.



Ref. article: Caring for patients with Diabetes Insipidus. Bryson,M.K. Nursing.96 http://search.ebscohost.com/login.aspx?direct=true&db=hch&AN=9606043595&site=ehost-live

Feb 1, 2009

Diabetic Retinopathy

Diabetes has become one of the most common disorders in the United States. Among the complications of the disease process, nerve damage occurs in 60-70% of individuals affected by this illness. According to the article, Diabetes is the leading cause of kidney failure and new cases of blindness in adults. Diabetic retinopathy affects the nerves of the retina. There are two categories : nonproliferative diabetic neuropathy and proliferative diabetic neuropathy, both ranging from mild to severe. Mild includes microaneurysms only, while severe involves severe retinal hemorrhages or venous beading in quadrants of the eye.


Diabetic neuropathy causes damage of the blood vessels in the retina. This occurs as a result of hyperglycemia which causes vascular damage. This also causes increased vascular permeability, decreased vascular tone, vascular leakage and edema. New blood vessels grow to compensate for the existing damaged blood vessels. These new blood vessels may be fragile which easily adhere to the vascular leakage which may cause blurred vision. They may also cause hemorrhage aneurysms which give symptoms of floaters or black spotted areas in the vision. All these lead to reduced visual acuity and ultimately to blindness.


Diabetic retinopathy mainly affects the retina of the eye. The retina contains the highest concentration of photoreceptors. According to the article, diabetic retinopathy may begin to develop years before an actual clinical diagnosis of diabetes is made. The standard tool used in testing Diabetic retinopathy is the visual acuity chart. This measures how well one can see at different distances or the visual acuity loss that occurred due to the disease process.

Description: Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity chart

Dilated eye exam may be done to widen or dilate the pupil enabling better visual of the eye and inner structures. eg. damaged nerve changes in the blood vessels, pale fatty deposits of retina (signs of leaking blood vessels) and retinal swelling. Tonometry may also be used in eye testing; this instrument measures the pressure inside the eye. The article further goes on to state that the three main mechanisms that contribute to blindness in diabetic retinopathy causing blindness includes: macular ischemia, retinal and vitreous hemorrhage and retinal detachment. Macular ischemia can be a slow process, which destroys light sensitive cells and retinal detachment can occur suddenly. This is an ophthalmic emergency as permanent loss of vision can occur if medical intervention is not immediately obtained.
Ref. article: Etiology and natural history of diabetic retinopathy: An overview. Morello, Candis M. American Journal of Health-System Pharmacy; 9.1.07 Supplement, Vol. 64,