Describe the 3 types of diabetes Insipidus. There are three types of diabetes insipidus, neurogenic, nephrogenic and dipsogenic. Neurogenic diabetes insipidus is the most common of the diabetes insipidus and it is cause by insufficient amounts of ADH (McCance and Huether, 2014). Neurogenic DI Occurs in three phases, the first one is polyuria that is due to the inhibition of ADH. The second phase is characterized by a near normal urinary output because of the release of stored ADH. The third phase is permanent excessive urinary output due to depletion of stored ADH is loss of the functioning cells that have produces ADH (John & Day, 2012). Nephrogenic DI is an insensitivity of the renal collecting tubules to ADH, this can be either genic or acquired. Nephrogenic DI causes complete or partial resistance of the kidneys to arginine vasopressin (Nephrogenic Diabetes Insipidus, 2018). Vasopressin is an antidiuretic hormone used by the kidneys to manage water balance in the body (Nephrogenic Diabetes Insipidus, 2018). Dipsogenic diabetes insipidus is when excessive fluid intake lowers the plasma osmolarity to the extent that it decreases below the threshold for ADH secretion (McCance & Huether, 2014). The consumption of excessive water will damage the kidneys, when this happens it suppresses ADH and stops the body from being able to concentrate the urine (Perkins, Yuan, & Welch 2006). 2) What lab values would you expect to see with each type? With Neurogenic DI the healthcare provider would note the patient’s specific gravity would be less the 1.005, urine osmolality would be less than 200 mOsm/kg, their serum osmolality would be elevated and the serum sodium level will be elevated as well (John & Day, 2012). Nephrogenic DI the healthcare provider will note that the patient has high levels of sodium in the blood, and very diluted urine. The healthcare provider may order a water deprivation test, this test measures urine production, electrolyte levels, and weight measurements throughout a 12 hours period where the patient is not allowed to drink (Nephrogenic Diabetes Insipidus, 2018). At the end of the test the healthcare provider injects vasopressin, and if the body responds to the vasopressin the diagnosis is confirmed. Testing for Dipsogenic DI testing includes the same methods as neurogenic and nephrogenic DI, a water deprivation test, urinalysis, and a MRI (Perkins, Yuan, & Welch 2006). 3) Describe the causes/potential causes of each type and how the treatment varies between the 3 types and why Neurogenic DI is usually caused by damage to the posterior part of the pituitary gland where ADH is stored and secreted. Neurogenic DI is also associated with neurosurgery, tumors, increased intracranial pressure, brain death, meningitis or encephalitis (John & Day, 2012). Treatment for neurogenic DI is to correct the ADH deficiency and to restore fluid balance by promoting sodium and water reabsorption. Desmopressin, vasopressin, or lypressin may be administered, patients are encouraged to continue drinking as much fluid as possible and if needed fluid can be replaced intravenously. Nephrogenic DI can be caused by drug use, kidney disease, or obstruction of the ureters. Nephrogenic DI can also be a temporary complication that is associated with pregnancy. Hereditary nephrogenic DI are inherited as X- linked recessive disorders (Nephrogenic Diabetes Insipidus, 2018). Treatment for dipsogenic DI is different then with neurogenic and nephrogenic DI. Medications are administered to the body to get rid of the excessive fluids, it is also important that the healthcare provider makes sure that the patients electrolyte balance is maintained (Perkins, Yuan, & Welch 2006). 4) What would indicate a “red flag “symptom in any of them and require urgent treatment Symptoms for nephrogenic, neurogenic and dipsogenic DI that would indicates a red flag would be excessive thirst and increased urine output. Case Study: A 30 yr. old female comes to see you for complaints of fatigue. She is 8 months post-partum and delivered a healthy baby. She thought her fatigue was initially due to post-partum, but states that the fatigue is worsening. She is also bothered by some weight gain over the past few months. What else would you want to ask in her review of systems? I would also want to ask if there was a history of thyroid disorders or if she had a family history of thyroid disorders. I would also ask her if she had any sensitivity to cold, dry skin, and problems having a bowel movement, and if she was having a hard time concentrating (Groer & Jevitt, 2014). 2) What specifics would you look for on physical exam? On her physical exam I would make sure to determine if her hear rate is bradycardic, puffiness around the eyes, and if the patient has a delayed relaxation phase with their deep tendon reflexes (Groer & Jevitt, 2014). I would also assess the thyroid by palpation and determine if it is irregular, firm, and nontender (Groer & Jevitt, 2014). 3) How would you explain to her the most likely cause of her symptoms and why this is happening? I would explain to her that Postpartum thyroiditis is an autoimmune disorder that causes thyroid dysfunction. Postpartum thyroiditis affects women in the first year after delivery (Groer & Jevitt, 2014). Postpartum thyroiditis can be related to Hashimoto’s disease, and that during pregnancy the immune system is partially suppressed and it rebounds drastically after delivery that causes an increase risk for autoimmune thyroid disease in patients with thyroid peroxidase antibodies (Groer & Jevitt, 2014).
