The Journal for Nurse Practitioners
Volume 6, Issue 7 , Pages 546-550, July 2010

Recognizing and Managing Pyschogenic Polydipsia in Mental Health

  • Sharon Valente

      Affiliations

    • Sharon Valente, RN, PhD, is the associate chief nurse of research and education and Diane Fisher, RN, CNS, works in informatics at the Department of Veteran Affairs in Los Angeles, CA.
    • ,
  • Diane Fisher

      Affiliations

    • Sharon Valente, RN, PhD, is the associate chief nurse of research and education and Diane Fisher, RN, CNS, works in informatics at the Department of Veteran Affairs in Los Angeles, CA.

Article Outline

Abstract 

Psychogenic polydipsia (PPD) or water intoxication with polyuria and polydipsia is common among patients with psychiatric disorders. Although the underlying pathology is unclear, PPD or drinking more than 3 liters of fluid daily can be a highly disabling and life-threatening condition. In half of the cases, it can lead to mortality because of cerebral edema and central nervous system dysfunction with delirium, seizures, coma, and death. Excessive drinking can accompany other repetitive behaviors in schizophrenic, bipolar, or psychotic patients. A screening program can detect cases early to minimize morbidity and mortality. This article describes the evidence-based screening, evaluation, and management of water intoxication or polydipsia and includes a case study to illustrate evaluation and management.

Keywords:  polydipsia , psychogenic , water intoxication

 

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Introduction 

Detection of polydipsia (e.g., hyperhydration or water intoxication) is a challenge for psychiatric nurses. It occurs when the consumption of water exceeds safe limits and creates a potentially fatal disturbance in brain function. It is rare among normal and healthy individuals and does not usually occur accidentally.1 The mechanisms of polydipsia are not well understood or diagnosed. It may progress from excessive water intake to complications (e.g., impaired water excretion and hyponatremia).2, 3, 4 Polydipsia may occur among 1% to 20% of people with chronic schizophrenia.4, 5 Polydipsia may have a slow and erratic course. It presents with excessive water intake that initially does not interrupt sleep with excess urination. While it is asymptomatic in mild and early forms, it becomes more severe with time, progressing to a syndrome with neurological abnormalities (e.g., headache, muscle cramps, blurred vision, weakness, tremors, restlessness, confusion, lethargy, delirium, seizures, coma, and death), behavioral and cognitive problems, gastrointestinal symptoms, urinary tract disease (e.g., incontinence, hydronephrosis, renal failure), congestive heart failure, and metabolic abnormalities (e.g., hypocalcemia, osteopenia).4 Risk factors in psychiatric patients include a lifelong history of excessive drinking, extended hospitalization, heavy smoking, and medications that cause dry mouth or thirst.6 When polydipsia progresses and includes hyponatremia, the diagnosis is often missed in psychiatric settings until the hyponatremia becomes severe and the patient has life threatening seizures. The nurse needs to recognize the risk of developing polydipsia, detect its symptoms, notify the attending psychiatrist, and monitor complications including seizures and coma.

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Case Example 

Nurses knew “Mr. Jones” well; he was a schizophrenic patient with a history of substance abuse, who was hospitalized for an acute exacerbation of schizophrenic symptoms (auditory hallucinations, ideas of persecution). The treatment goals were to start medications and stabilize the acute symptoms. The nurses' notes indicated that he was frequently disoriented, restless, and forgetful (i.e., symptoms of polydipsia) and would leave the day room to pace in the hall. He complained of weakness. He was always drinking water and juice. He was a loner who had minimal interaction with others. Because nurses had emphasized hand washing to reduce the risk of multidrug-resistant Staphylococcus sp infection and influenza, they thought his frequent trips to the restroom were for hand washing. Staff did not realize that the disorientation, forgetfulness, and excess fluid intake and output signaled polydipsia.

A night nurse was suspicious; she thought he drank a lot of water and she recommended diabetes screening, but the results were normal. The nurses noted that his confusion and forgetfulness increased along with flushing and sweating but did not identify these as increasing symptoms of polydipsia. One evening he was rushed to the emergency department with confusion and hyponatremia. These experienced psychiatric nurses were amazed that he went to emergency. In retrospect, a few thought he might have had diabetes, but no one considered polydipsia or looked for its symptoms. During treatment, his serum sodium level reached 140 meq/L. His hyponatremia was treated with diuresis and electrolyte replacement. Because of the potentially fatal complications, nurses wanted to know how to detect, evaluate, and prevent polydipsia and water intoxication.

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Etiology and Pathophysiology 

Although drinking water appears healthy, over-hydrating can lead to swelling of the brain and disrupt vital functions, such as breathing, and cause death. Usually healthy kidneys eliminate 1 liter of water per hour or about 20 L/day, but stress and disease can reduce this amount.2 Nerve transmission and muscle function require adequate sodium balance, and even a slight reduction in sodium can cause imbalance. The kidneys, pituitary gland, and hypothalamus, as well as volume receptors in the aortic arch and cardiac atria, interact to control thirst and production of urine. When the anterior hypothalamic thirst center is stimulated, polydipsia occurs. Polydipsia is the consumption of greater amounts of water than normal. Normally, when excess thirst occurs, it stimulates polydipsia to compensate for the thirst. It then stimulates polyuria to eliminate the excess fluid. When you drink too much water but do not excrete it adequately, the fluid overpowers the kidneys so they cannot process and eliminate the fluid effectively. The excess water lowers salt and electrolyte concentrations, dilutes the blood, and moves to the cells and organs, such as the brain, where it causes swelling. The skull prevents the brain from expanding. The swelling causes confusion, forgetfulness, and tremors. Among inpatients, hyponatremia is the electrolyte most commonly disrupted, so clinicians consider the common medical causes of hyponatremia and may not think about polydipsia.4 It may also be caused by kidney dysfunction or increased action of antidiuretic hormone.

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Assessment 

The evaluation of polydipsia is a challenge because symptoms such as confusion are often misdiagnosed as drug abuse or a medical condition. Risk factors include psychiatric disorders, gastritis, endurance sports, pregnancy, and medical disorders (e.g., tumors, diuresis, deficient mineralocorticoids, osmotic diuresis [e.g., uncontrolled diabetes with hyperglycemia], human immunodeficiency virus (HIV) infection, and AIDS-related disorders can commonly cause electrolyte imbalance with or without water intoxication.2, 4 Occasionally, parenteral nutrition can cause an overload if fluids are not carefully balanced and monitored.

Medical history includes questions about the nature and duration of the polydipsia and any recent increase in symptoms or psychiatric, cardiac, or thyroid problems. Potential causes of the disorder include medications, exercise, heart failure, or acute dehydration. Information about urine color and amount of urinary output, frequency of urination at night, and dependent edema would help differentiate the medical causes of polydipsia. Questions about nocturnal drinking and cognitive symptoms (e.g., dizziness, confusion, forgetfulness) would be useful. Often patients cannot easily estimate the amount of fluid they drink, so providing typical containers of different sizes such as a cup, an 8-oz water bottle, and a larger drink container as visual aids help patients describe fluid intake.

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Screening 

Most self-report screening instruments are brief and easy to use and take about 5 to 10 minutes to complete. Screening instruments provide objective data that can support the need for further evaluation or treatment. Screening tests should apply to the population of interest; address the symptoms and help clinicians with assessment. The instrument should demonstrate reliability and validity and be well tested in the population. Once a screening tool indicates scores above normal, the patient typically requires a comprehensive evaluation. The 17-item Polydipsia Screening Tool (PST) helps evaluate patients who are at risk.6 This tool screens patients efficiently, particularly in settings where staff may have limited experience in identifying at-risk patients. The items and symptoms were derived from a review of the literature. The tool was tested for interrater reliability (where r 5 0.84) and validity.

Routine screening in clinic and at admission should be used to evaluate those with a diagnosis of schizophrenia, bipolar disorder, psychosis, mental retardation, psychosis, substance abuse, and organic mental syndromes. Schizophrenia typically accounts for 80% of the diagnoses of polydipsia and water intoxication.6 While dilute urine characterizes compulsive water drinking and diabetes insipidus, baseline hyperosmolarity suggests the latter. Serum sodium and urine osmolality can be tracked.

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Differential Diagnosis 

Diagnosis of polydipsia reflects an awareness of pathology and the pattern of associated symptoms (e.g., polyuria, polyphagia, weakness, and weight loss).2 Some combination of these symptoms may be present but not necessarily all of them. A medical history will rapidly differentiate the common causes of polydipsia (e.g., hyperglycemia, renal insufficiency, cardiac problems, or surgery without fluid replacement). A pattern of polydipsia, polyuria, and excessive appetite suggests diabetes mellitus or hyperthyroidism. Polydipsia and polyuria would indicate diabetes insipidus. If poor transport and excretion of fluid are the causes, shock or congestive heart failure should be considered.7 The laboratory workup involves checking intake and output, blood glucose level (to rule out diabetes), electrolytes, and a thyroid profile. Some medications (e.g., lithium) can be accompanied by water intoxication and require consideration. Disorders such as dehydration, diabetes, Cushing's syndrome, diarrhea, and fever should be ruled out.

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Treatment 

When mild intoxication occurs, it may be asymptomatic and need restriction of fluid. When symptoms are more severe, treatment uses diuresis to increase urination (e.g., effective for excess blood volume), and intravenous saline to balance sodium electrolytes, and vasopressin receptor antagonists.8, 9 Some researchers report that urea and clonidine are useful.9, 10 Medications for primary or psychogenic polydipsia in psychiatry include antihypertensives (e.g., propranolol and angiotensin-converting enzyme inhibitors; other interventions involve opioid antagonists as well as clozapine and risperidone). Behavioral treatment can effectively teach and reward psychiatric patients for reduced excess fluid consumption. These interventions are monitored by frequent weighing to monitor diurnal weight gain, involuntary restriction of fluids, and reinforcement programs.

The treatment goal of polydipsia is to help the patient gain independence and restore electrolyte balance. Verghese et al.11 suggest three primary categories of pharmacological interventions. The first category is the use of the antihypertensive medication propranolol (Inderal). Propranolol is a beta-adrenergic receptor antagonist that has been shown to decrease fluid intake in animal and human studies. Patients generally respond well to this drug when it is taken before meals and at bedtime. Mild and transient side effects can occur (e.g., hypotension, low heart rate, abdominal cramping), gastrointestinal symptoms (e.g., diarrhea, constipation). Patients may also report fatigue, weight gain, depression, and wheezing, particularly in cases of asthma. Antacids containing alcohol and aluminum decrease propanolol's effectiveness. Although more study is indicated it is believed that this effect results from a decrease in the production of angiotensin II (AII), which is a known dipsogen.11

Another strategy involves angiotensin-converting enzyme inhibitors. A stimulant of the adrenal cortex, angiotensin prompts release of the hormone aldosterone, which encourages sodium retention and is a potent dipsogen. Captopril and enalapril are two such medications that have both shown promise in a small number of case studies. Captopril is taken regularly before meals and at a routine time each day. Potassium supplements or salt substitutes containing potassium that raise potassium levels should be avoided. Although side effects are rare, potassium supplements can cause serious side effects, such as muscle weakness or bradycardia. Patients may report transient side effects such as being light-headed and having a decreased sense of taste, nonproductive cough, or blurred vision. Patients should promptly report uncommon side effects (e.g., fainting, sexual side effects, tachycardia, and angina). Further study is warranted to determine if these findings are generalizable.

The third approach is the use of opioid antagonists. A fourth approach is the use of clonidine. The exact effect of clonidine on polydipsia is not known, but it is believed that clonidine may significantly recalibrate key clinical parameters of sodium.11, 12 Common side effects that resolve with prolonged therapy or dose reduction include tiredness, sleepiness, constipation, and dry mouth. Patients may also report feeling dizzy or weak and having headaches. Skin redness, itching, and darkening may occur with clonidine patches. Sexual dysfunction may include problems with ejaculation, desire, and impotence. If clonidine is not tapered, rebound high blood pressure can occur.

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Behavioral Therapy 

Behavioral therapies are essential for treating polydipsia and helping families manage this problem at home, in clinic, and in inpatient settings. The care plan needs to reflect monitoring and risk for polydipsia. If the patient does not cooperate in accurately reporting intake and output, diurnal weight gain can track fluid intake.13 Among the most successful therapies is the restriction of water with contingencies. Patients report they drink excessively to cope with anxiety, cognitive difficulties, boredom, and sadness. Nursing education helps the patient develop an increased awareness of water intake and can teach the patient to participate in treatment and goal planning. Patients should record the time, amount, type of fluid, and activity or situation for each liquid they drink. A 500-mL water bottle helps measure fluid intake, and patients can fill it according to a schedule six times daily, about every 2.5 h. If the patient drinks from a fountain or a shower or a beverage in another container is consumed, the equal amount of fluid in the measuring bottle is removed. Intake and output should be tracked as much as practical. Allow the patient to select their preferred reinforcement. Weigh the patient in the morning and evening. Enforce involuntary water restriction if the weight gain is more than 5%. Reward the patient if they do not ask for water anytime other than the specified time. Reward the patient if they have a weight gain of less than 5%.11, 12, 13

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Education 

Teach the patient about the risks of polydipsia and about self-monitoring techniques. Teach family members and all caretakers the signs and symptoms of polydipsia as well as intervention strategies for use in the outpatient setting. The APRN educates the patient, family, or caretakers to

•Monitor the patient's water intake

•Weigh the patient each morning and evening or more frequently if necessary

•Provide frequent positive reinforcement

•Teach the patient and family the signs and symptoms of polydipsia and reinforce the risks of failing to comply with the treatment plan

•Involve the patient in establishing types of positive and negative reinforcement. The patient can identify rewards and penalties that will help encourage the safe consumption of water.

•Monitor chronic-care psychiatric patients for evidence of polydipsia

•Recognize that a family history of alcohol abuse problems may be a risk factor for developing polydipsia

•Encourage family involvement in assessing, monitoring, and treating polydipsia at home

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Prevention 

Balancing the daily intake of water with water losses can prevent polydipsia.9 Tracking intake and output encourages prevention. The PST helps identify those at risk on admission. Most people prevent polydipsia because thirst triggers drinking. Healthy kidneys can eliminate about 1 liter of fluid per hour. Stress, prolonged physical exertion, and diseases can impair normal kidney function. Athletes often use sports drinks because their electrolytes support extended exercise. However, these sports drinks do not provide adequate electrolytes to balance excessive intake. APRNs need to be aware of this overlooked condition that can have dangerous and potentially lethal complications. Since patients generally have a primary psychiatric diagnosis of schizophrenia, and other conditions, the psychopathology also complicates matters

Polydipsia or drinking more than 3 liters of fluid daily can be a highly disabling and life-threatening condition. Accurate assessment and diagnosis are pivotal to preventing these complications. In at-risk populations, clinicians can use the PST to identify those who need further evaluation. Educating patients and families with at-risk factors will help prevent polydipsia. Although management with medications and behavioral therapy is effective, education and prevention are more beneficial. Advising healthy patients who exercise about the dangers of water intoxication is also useful.

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References 

  1. Bird PJ . You can drink too much water . University of Florida; 2007;
  2. Bhanaker SM , Paek R , Vivalala MS . Water intoxication and symptomatic hyponatremia after outpatient surgery . Anesthesia Analog . 2004;1294–1296
  3. Goldman MB . Disorders of water balance in psychiatric patients . Int Drug Ther News . 2007;42(4):27–34
  4. Dundas B , Harris M , Narasimhan M . Psychogenic polydipsia review: etiology, differential, and treatment . Curr Psychiatry Rep . 2000;9(3):236–241
  5. Delva NJ , Chang A , Hawken ER , Lawson JS , Owen JA . Effects of clonidine in schizophrenic patients with primary polydipsia: three single case studies . Prog Neuropsychopharmacol Biol Psychiatry . 2002;26(2):387–392
  6. Reynolds SA . Polydipsia screening tool . Arch Psychiatr Nurs . 2004;8(2):49–59
  7. Bersani G , Pesaresi L , Orlandi V , Gherardelli S , Pancheri P . Atypical antipsychotics and polydipsia: a cause or a treatment? . Hum Psychopharmacol . 2007;22(2):103–107
  8. Gibson CA , Stewart JT . Treatment of psychogenic polydipsia with pindolol . J Clin Psychopharmacol . 2006;26(1):99–100
  9. Webber MA , Ofalabi I , Mahmud W , Herron MS , Shekhar A . Losartan for treatment of psychogenic polydipsia . Ann Pharmacother . 2004;38(10):1750–1751
  10. Verhoeven A , Musch W . Treatment of the polydipsia-hyponatremia syndrome with urea . J Clin Psychiatry . 2005;66(11):1372–1375
  11. Verghese C , de leon J , Josiassen R . Problem and progress in the treatment of polydipsia and hyponatremia . Schizophr Bull . 1996;22(3):455–464
  12. Pavaloinis D , Shutty M , Hundley P . Behavioral interventions to reduce water intake in the syndrome of psychosis, intermittent hyponatremia, and polydispia . J Therapeutics Experiment Psychiatry . 1992;51–57
  13. Costanza ES , Antes LM , Christensen AJ . Behavioral and medical treatment of chronic polydipsia in a patient with schizophrenia and diabetes insipidus . Psychosom Med . 2004;66:283–286

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Uncited references 

  1. de Leon J . Polydipsia: a study in a long-term psychiatric unit . Eur Arch Psychiatry Clin Neurosci . 2003;253(1):37–39
  2. Rosner MH . Severe hyponatremia associated with the combined use of thiazide diuretics and selective serotonin reuptake inhibitors . Am J Med Sci . 2004;327(2):109–111
  3. Ribble DJ , Thelander B . Patients with disordered water balance . J Psychosoc Nurs Ment Health Serv . 1994;32(10):35–42
  4. Umansky L , Sella A . Psychogenic polydipsia leading to water intoxication . Harefuah . 2000;138(1):9–12 87.

 In compliance with national ethical guidelines, the authors report no relationships with business or industry that would pose a conflict of interest.

PII: S1555-4155(10)00158-3

doi:10.1016/j.nurpra.2010.03.004

The Journal for Nurse Practitioners
Volume 6, Issue 7 , Pages 546-550, July 2010

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