21.4 Pituitary Disorders

Clinical Manifestations

The main clinical manifestations of DI are extreme thirst (polydipsia) and the production of large amounts of urine (polyuria)—more than 3 liters in a 24-hour period. This occurs both day and night, making them distinguishing features of DI (Perkins, 2020). Other common signs and symptoms are dehydration, hypernatremia, fatigue, hypotension, tachycardia, dizziness, weakness, fatigue, and loss of consciousness. Patients with DI are also at risk for hypovolemic shock.

Diagnostics and Laboratory Values

Assessing for DI relies on a thorough patient history and assessment. Diagnostic testing can confirm a parathyroid disorder when signs and symptoms are present. Diagnosis of DI involves confirming polyuria, determining which type of DI is present, and figuring out the underlying cause (Perkins, 2020). A 24-hour urine sample will be collected to identify polyuria. Urine and blood osmolality will also be measured, showing a decreased urine osmolality and increased serum osmolality. Serum sodium levels will also be evaluated. Other assessments that may be completed include the fluid deprivation test and the hypertonic saline infusion test.

A fluid deprivation test involves restricting the patient’s fluid intake while monitoring the patient’s body weight and urine concentration. A positive test will show continued urine dilution and decreased urine osmolality.

Nursing Care of the Patient with Diabetes Insipidus

When caring for patients with DI, it is important to closely monitor intake and output, daily weights, vital signs, changes in level of consciousness, skin turgor, mucus membranes, and laboratory values. Accurate, strict intake and output is important to monitor the patient for dehydration. It is also important to monitor the patient at the same time each day, using the same scale if possible. Assessment of skin turgor and mucus membranes can also be quick indications of the patient’s hydration status. Evaluation of laboratory values is also important to monitor for electrolyte imbalances and kidney dysfunction.

Recognizing Cues and Analyzing Cues

A patient constantly requesting water to drink and taking multiple trips to the bathroom is a cue for the nurse that the patient may have DI. It is important to utilize acute assessment skills along with targeted subjective questions to gather the appropriate data. When completing a subjective assessment, ask the patient targeted questions about their quality of life. Questions may include:

• Do you struggle with fatigue or feeling unwell?
• Are you having problems with irritability or concentration?
• How often do you urinate? Does it interfere with sleep?
• Have you had unplanned weight loss?

Obtain an accurate list of all medications the patient is currently taking, as some medications can cause polydipsia, polyuria, and hyponatremia. An objective assessment of a patient with DI may reveal tachycardia, hypotension, and dry skin and mucous membranes.

Prioritizing Hypotheses, Generating Solutions, and Taking Action

Additional cues, such as large volumes of clear urine, poor skin turgor, and dry mucus membranes, may further support a hypothesis that the patient has DI. The nurse should be sure to collaborate with the interdisciplinary team to identify and treat the underlying cause, implement appropriate interventions, re-evaluate therapies and plan of care, and include the patient and family in the plan of care.

When educating the patient and family, be sure to emphasize the following points:

• Importance of monitoring intake and output at home
• Daily weight checks at the same time and using the same scale
• Signs and symptoms of dehydration to report to the practitioner (e.g., dry skin and mucous membranes, persistent and intense thirst, reduced urine output or concentrated dark-colored urine, low blood pressure with associated dizziness or lightheadedness, a rapid heart rate)
• Benefits of wearing a medical alert bracelet stating the patient has DI

Evaluation of Nursing Care of the Patient with Diabetes Insipidus

The nurse should evaluate the outcomes of care with both the patient and their family. For patients with DI, positive outcomes would be intake, output, and electrolyte balance. If these outcomes are not met, the nurse should evaluate what could have been done differently. Was the patient engaged in during their treatment? How could the nurse modify care interventions to meet goals?

Evaluating Outcomes

Effective nursing care prevents complications of DI, provides the patient with education about the disease, and identifies signs and symptoms of dehydration or hypovolemic shock. Questions the nurse can ask to evaluate nursing care include:

• Did the patient maintain a balanced intake and output?
• Did the patient actively participate in monitoring their intake and output?
• Did the patient experience any electrolyte imbalances?
• Did communication remain open between the patient, nurse, and practitioner throughout care?

Medical Therapies and Related Care

Treatment strategies for DI include treating the underlying cause and ensuring the patient drinks enough fluids to maintain hydration. Desmopressin is typically administered to replace vasopressin in the body and act as an antidiuretic hormone to treat polyuria. If a tumor is present, the pituitary gland may be removed—a procedure called a hypophysectomy. Discontinuing nephrotoxic medications may return the kidneys to normal function. A thiazide diuretic may be prescribed in cases of low ADH production to reduce urine production (Perkins, 2020).

Clinical Manifestations

Clinical manifestations of SIADH are usually due to decreased extracellular fluid osmolality and hyponatremia. This causes cerebral edema. Early signs and symptoms of SIADH are malaise, nausea, and vomiting. As sodium levels continue to fall, lethargy, headache, obtundation, and seizures may occur, followed by coma and respiratory arrest if sodium levels fall below 120 mEq/L.

Diagnostics and Laboratory Values

A subjective assessment for SIADH involves asking the patient targeted questions about their quality of life. Diagnostic testing can further evaluate disease progression. Serum osmolality and serum sodium will both be low in patients with SIADH. Urine sodium levels will be elevated due to increased free water absorption in the renal collecting tubules. The state of having a normal volume of fluids in the body, or euvolemia, will be present.

Diagnostic testing should rule out underlying causes, such as hypothyroidism or adrenal insufficiency. Other tests—such as kidney and liver function testing, thyroid profile, fasting lipid profile, serum electrolytes, and serum cortisol levels—should also be evaluated. Patients with pulmonary symptoms or a history of smoking may have a CT scan or chest X-ray to rule out lung cancer (Yasir & Mechanic, 2023).

Nursing Care of the Patient with SIADH

Similar to DI care, the nurse should closely monitor intake and output, daily weights, vital signs, changes in level of consciousness, mental status, and laboratory values. It is also important to assess for Cheyne-Stokes respirations and to monitor the patient’s weight at the same time each day, using the same scale if possible. Evaluation of laboratory values is also important to monitor for electrolyte imbalances and acute kidney injury.

Recognizing Cues and Analyzing Cues

When completing a subjective assessment, questions may include:

• Do you struggle with headaches, lethargy, dizziness, or confusion?
• Are you having GI problems, such as nausea and vomiting?
• Have you had unplanned weight gain?
• Are you having any chronic pain?
• Have you had any head trauma?

Obtain an accurate list of all medications or illicit drugs the patient is currently taking.

An objective assessment of a patient with suspected SIADH may reveal normal skin turgor, moist mucus membranes, and absence of edema. A detailed neurological assessment may show lethargy, speech difficulties, sluggish deep tendon reflexes, and tremor. A respiratory assessment may show Cheyne-Stokes respirations in severe cases. These are characterized by cyclical episodes of hyperventilation and apnea and are a sign of cardiac damage.

Prioritizing Hypotheses, Generating Solutions, and Taking Action

Signs of fluid overload and heart failure are a high priority. The nurse will closely monitor the patient’s cardiac output through blood pressure, heart rate, respiratory rate, and absence of chest pain. Intake and output, as well as daily weights, are also important to monitor fluid balance. Because of the excess water in the body, patients with SIADH are at risk for cerebral edema and seizures from low levels of sodium, so patient safety measures such as seizure precautions should be initiated. The nurse should ensure the proper administration of prescribed loop diuretics to aid in the elimination of excess water.

When educating the patient and family, be sure to include:

• The importance of monitoring intake and output at home
• Daily weight checks at the same time and using the same scale
• Signs and symptoms of hyponatremia to report to the practitioner

Evaluation of Nursing Care of the Patient with SIADH

Nursing interventions should always remain flexible in order to meet goals. Modifications to the nursing plan of care should be based upon the evaluation of the effectiveness of measures implemented to correct SIADH. A patient who isn’t compliant with a fluid restriction, for example, may need re-education about its importance and goal adjustment to increase compliance.

Evaluating Outcomes

Effective nursing care prevents complications of SIADH, provides the patient with education about the disease, and identifies signs and symptoms of severe hyponatremia. A primary patient outcome related to SIADH management is to prevent further accumulation of excess water in the body. This can be evaluated through intake and output monitoring. Laboratory values can also show trending sodium and osmolality. Questions the nurse can ask to evaluate nursing care include:

• Did the patient maintain a balanced intake and output?
• Did the patient actively participate in monitoring their intake and output?
• Did the patient experience any signs or symptoms of hyponatremia?
• Was the patient compliant with fluid restrictions?
• Did communication remain open between the patient, nurse, and practitioner throughout care?

Medical Therapies and Related Care

Treatment for SIADH involves treating the underlying condition (such as pulmonary or CNS infection) and preventing any further decrease in sodium levels. For patients with mild symptoms of hyponatremia, an oral fluid restriction of less than 800 ml/day is initiated. If hyponatremia persists, oral or intravenous sodium chloride is given. Loop diuretics, such as furosemide, may be given to increase water excretion and decrease urine concentration.

Patients with severe symptoms, such as seizures and delirium, are given 100 mL IV boluses of hypertonic saline over three to four hours in addition to a water restriction. Serum sodium levels are closely monitored in between boluses to prevent rapid sodium increase. The brain is able to adjust to chronic hyponatremia and protect itself from severe brain swelling from the increase in water. When sodium levels raise too rapidly, the brain is unable to adjust and water is pulled from the nerve cells, causing dehydration damage to the brain that can be permanent.

Vasopressin receptor agonists, such as tolvaptan or conivaptan, may be prescribed for persistent SIADH. These medications prevent free water retention caused by ADH excess and help correct hyponatremia.