Diagnosis Of Polyuria Research Articles

Accidental ketosis-induced polyuria in a toddler: a case report

BackgroundIn the pediatric population, parental concern of recent onset frequent or large volume urination in young children is common.Case presentationA 2-year-old male with no significant past medical history and unremarkable family history was brought to his pediatrician by his mother who reports that the child had been “soaking through his diapers” for the previous two to 3 days. Mother states that patient has not had an appreciable change in the number of wet diapers per day, just the perceived weight/volume of each diaper. The patient’s mother denied any recent illness, apparent abdominal pain, dysuria, or recent changes in his bowel movements. She similarly denied polydipsia, polyphagia, or gross hematuria in the patient. Patient’s diet consists of eating a low carbohydrate with mostly high protein and fat diet that was similar to the paleo-type diet consumed by her and her husband. Meals over the recent days were even lower in carbohydrates than usual as the family was actively trying to consume healthier food options.On physical exam the child was found to be afebrile with a normal physical exam. A urine dipstick was performed and was positive for 2+ ketones and 1+ protein. Urine leukocytes and nitrites were negative, as was urinary glucose. A fingerstick blood glucose sample was 83 mg/dL.Based on the patient’s physical examination, laboratory findings, and the history which revealed a very-low carbohydrate diet, a preliminary diagnosis of ketosis-induced polyuria was made. The patient’s mother was advised to incorporate a greater portion of carbohydrates into her son’s diet, with a follow-up scheduled for the following week. At the follow-up appointment the mother reports that she had continued the patient’s carbohydrate intake and the excessive urine amount per wet diaper has not returned. Repeat urine dipstick confirmed the resolution of the ketonuria and proteinuria.ConclusionThis case illustrates the inadvertent consequences that can occur when parents impose new fad diets on their young children. The recent increase in the popularity of fad diets makes the consideration of alternative diets important to review in the patient history and subsequently include in the differential diagnosis of polyuria.

A Comparison of Plasma Vasopressin Measurements With a Standard Indirect Test in the Differential Diagnosis of Polyuria

The diagnoses provided by a standard indirect test of vasopressin function were compared with those obtained by radioimmunoassay of plasma vasopressin in 24 patients with nonglucosuric polyuria. All seven cases of severe neurogenic diabetes insipidus diagnosed by the indirect tests were confirmed by the vasopressin assay. However, two of six patients with partial neurogenic diabetes insipidus by indirect criteria had normal vasopressin secretion by the direct assay; one was found to have primary polydipsia, and the other nephrogenic diabetes insipidus. Moreover, three of 10 patients diagnosed as having primary polydipsia by the indirect test had clear evidence of partial vasopressin deficiency by the direct assay. The inability of the indirect test to distinguish accurately between partial neurogenic diabetes insipidus and primary polydipsia may be explained by increased sensitivity to low concentrations of vasopressin in the former disorder and a reduction of maximal concentrating ability in both. We conclude that the incorporation of a vasopressin assay improves accuracy in the differential diagnosis of polyuria.

Diabetes Insipidus Following Cardiorespiratory Arrest

Diabetes insipidus following cardiac arrest and hypoxemic encephalopathy occurred in two patients. In both, severe hypoxemic brain damage was followed within three days by clinical and laboratory features of diabetes insipidus, which were corrected by administration of exogenous vasopressin. Hypothalamic injury resulting in diabetes insipidus should be considered in the differential diagnosis of polyuria and dehydration occurring in critically ill patients who have suffered cardiorespiratory arrest.