Polydipsia differential diagnosis
Polydipsia Microchapters |
Diagnosis |
---|
Treatment |
Case Studies |
Polydipsia differential diagnosis On the Web |
American Roentgen Ray Society Images of Polydipsia differential diagnosis |
Risk calculators and risk factors for Polydipsia differential diagnosis |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Psychogenic polydipsia is a type of polydypsia with described in patients with mental illnesses and/or the developmentally disabled. It is present in a subset of schizophrenics. These patients, most often chronic schizophrenics with a long history of illness, often exhibit enlarged ventricles and shrunken cortex on MRI, making the physiological mechanism difficult to isolate from the psychogenic. It is a serious disorder and often leads to institutionalization as it can be very difficult to manage outside the inpatient setting. It should be taken very seriously - it can be life threatening as serum sodium is diluted to an extent that seizures and cardiac arrest can occur. Patients have been known to seek fluids from any source possible.
Polydipsia in Psychiatric patients
In treatment resistant polydipsic psychiatric patients, regulation in the inpatient milieau can be accomplished by use of a weight-water protocol. First, baseline weights must be established and correlated to serum sodium levels. Weight will normally fluctuate during the day, but as the water intake of the polydipsic goes up, the weight will naturally rise. The physician can order a stepped series of interventions as the weight rises. The correlation must be individualized with attention paid to the patient's normal weight and fluctuations, diet, co-morbid disorders (such as a seizure disorder) and urinary system functioning. Progressive steps might include redirection, room restriction, and increasing levels of physical restraint with monitoring. Such plans should also progressive increases in monitoring, as well as a level at which a serum sodium level is drawn.
It is important to note that the majority of psychotropic drugs (as well as many of other classes) can cause dry mouth, but this is not to be confused with true polydipsia in which a dangerous drop in serum sodium will be seen.
While psychogenic polydipsia is generally not found outside the population of those with serious mental disorders, there is some anecdotal evidence of a milder form (typically called 'habit polydispsia' or 'habit drinking') that can occasionally be found in the absence of psychosis or other mental conditions. The excessive levels of fluid intake may result in a false diagnosis of diabetes insipidus, since the chronic ingestion of excessive water can produce diagnostic results that closely mimic those of mild diabetes insipidus.