Children with diabetes insipidus associated with the lack of thirst (adipsia) may experience severe oscillations in their serum sodium levels requiring frequent and prolonged hospitalizations. On one hand, they are at risk of hyponatraemia resulting from excessive fluid intake due to absolute or relative overdosage of desmopressin. On the other hand, due to the absence of thirst, they are also at risk of hypernatraemia due to fluid deprivation if lost fluids are not properly replenished.1,2
We present the cases of 3 children with panhypopituitarism with antidiuretic hormone deficiency (central diabetes insipidus) and adipsia as immediate complications of surgical removal of large hypothalamic tumours. After a protracted postoperative hospital stay due to countless episodes of hyponatraemia and hypernatraemia, patients could be discharged home and managed at the outpatient level by providing parents with a portable system for measuring capillary blood sodium levels at home.
The patients were 2 girls and 1 boy aged 5.5, 15 and 9 years, respectively, that had undergone surgery for treatment of craniopharyngioma, optic nerve glioma and mixed germ cell tumour and were hospitalised for 96, 105 and 53 days (42, 9 and 23 of these days in the intensive care unit). The complications from abnormal sodium levels in these patients included status epilepticus and cerebral oedema secondary to hyponatraemia in the 2 younger patients and thromboembolic disease secondary to hypernatraemia in the adolescent patient.
We provided parents with a portable blood analysis device (EPOC point-of-care blood analysis system; Epocal Inc, Ottawa, Canada) that has been validated for measurement of capillary blood sodium concentrations on account of the good correlation of these measurements with those obtained by benchtop methods.3 The system requires 92μL of capillary blood per test and provides results in 3.5min, with an approximate cost of 5 euro per measurement. The device is portable, as it weighs only 680g, and can perform 50 measurements on one battery charge. We held a training session for parents and primary care providers (paediatricians and nurses) on the use of this system, and during the hospital stay we trained parents on how to collect capillary blood samples, on the management protocol and how to respond to abnormal sodium levels. Table 1 presents the contents of the printout of recommendations given at discharge. Families were informed that they could contact the clinic by telephone between 13:30 and 15:00 pm on weekdays.
Printout of recommendations given to parents for home-based care after hospital discharge.
| Prevention of hypernatraemia |
| Administer a fixed amount of fluids daily to cover baseline needs and immediately replenish fluid losses of any kind, including: |
| Polyuria: replenish the volume in excess of the usual urine volume |
| Insensible losses (heat, fever, physical activity or tachypnoea), gastrointestinal losses (diarrhoea, vomiting) or other fluid losses (haemorrhage, effusion, etc) |
| Prevention of hyponatraemia |
| Before administering DP, wait for the effects of the previous dose to be done (abundant and clear urine) |
| Avoid excessive fluid intake |
| Serum sodium measurements |
| Regular measurements (every 1, 2 or 3 days, depending on stability of patient), plus measurement in the event of any disease or symptom |
| Acceptable values in these children range from 138 to 148mEq/L |
| Sodium <138mEq/L (hyponatraemia or level in the lower limit of normal) |
| In case of mild symptoms (nausea, vomiting, headache) or no symptoms: restrict fluids and wait for urine to be abundant and clear before administering another dose of DP. Reduce total daily fluid intake by 5% |
| In case of severe symptoms (confusion, respiratory distress, coma, seizures, apnoea): alert the emergency department to prepare administration of IV hypertonic saline solution |
| Sodium >148mEq/L (significant hypernatraemia) |
| In case of no symptoms or mild symptoms (irritability): replenish dehydration losses properly and increase the total daily fluid intake by 5% |
| In case of severe symptoms (hypertonia, hyperreflexia, decreased level of consciousness): contact emergency department and bring patient for IV rehydration |
DP, desmopressin; IV, intravenous.
The 3 families assumed the responsibility to monitor serum sodium levels at home, which they preferred over visiting a health care centre or laboratory. The patients have returned to school and leisure activities, and parents have returned to work. At the time of this writing, the duration of at-home follow-up in the 3 patients has been of 20, 10 and 7 months, with a follow-up visit at our clinic every 3 months. In this interval, they have needed to visit the emergency department 6 times for reasons related to their sodium levels (Table 2), leading to short hospitalizations (<48h), except in one case in which hypernatraemia triggered acute kidney injury, which prolonged the hospital stay to 14 days.
Emergency department visits during home-based follow-up after hospital discharge with home monitoring of capillary blood sodium levels.
| Patient (age) | Reason | Serum sodium (mEq/L) | Length of stay |
|---|---|---|---|
| 1 (5.5 years) | Convulsive seizures | 139 (previous, 155) | 24h |
| 1 (5.5 years) | Status epilepticus | 126 | 48h |
| 1 (5.5 years) | Convulsive seizures | 132 | 6h |
| 2 (9 years) | Confusion | 132 | 6h |
| 3 (15 years) | Confusion | 170 | 14 days |
| 3 (15 years) | Fever and difficulty eating | 157 | 24h |
Home monitoring of capillary blood sodium levels is a rare practice, with barely half a dozen of children using this approach reported in the current international literature, but this measure is completely accepted by its users.4–6 With its implementation, we are taking another step to increase patient safety, family quality of life and, ultimately, to make paediatrics practice more humane. The use of home serum sodium monitoring could facilitate patient discharge, reduce the frequency of readmissions and the associated lengths of stay, reduce the number of visits to health care centres, allow an earlier return to school, work and leisure activities and open more time for children to enjoy their childhoods. A structured educational programme is essential in this approach to facilitate adherence to treatment by the family and good communication between health professionals (nurse-paediatrician) and between levels of care (primary care-hospital-based care).
Please cite this article as: Peinado Barraso MC, García García E. Monitorización domiciliaria de sodio en niños con diabetes insípida y adipsia. An Pediatr (Barc). 2020;93:262–264.
