Morbidity and mortality associated with vasopressin replacement therapy in children

Central Diabetes Insipidus in Infancy With or Without Hypothalamic Adipsic Hypernatremia Syndrome: Early Identification and Outcome

CONTEXT

Neonatal central diabetes insipidus (CDI) with or without adipsia is a very rare complication of various complex hypothalamic disorders. It is associated with greater morbidity and a high risk of developing both hypernatremia and hyponatremia, due to the condition itself or secondary to treatment with vasopressin analogs or fluid administration. Its outcomes have yet to be evaluated.

OBJECTIVE

To investigate the clinical outcomes of patients with neonatal-onset CDI or adipsic CDI with hypernatremia.

DESIGN, SETTING, AND PARTICIPANTS

All patients diagnosed with neonatal CDI in a university hospital-based observational study and followed between 2005 and 2015 were included and analyzed retrospectively.

MAIN OUTCOME MEASURES

The various causes of CDI were grouped. Clinical outcome and comorbidities were analyzed.

RESULTS

Ten of the 12 patients had an underlying condition with brain malformations: optic nerve hypoplasia (n = 3), septo-optic dysplasia (n = 2), semilobar holoprosencephaly (n = 1), ectopic neurohypophysis (n = 3), and unilateral absence of the internal carotid artery (n = 1). The other two were idiopathic cases. During the median follow-up period of 7.8 (4.9-16.8) years, all but one patient displayed anterior pituitary deficiency. Transient CDI was found in three (25%) patients for whom a posterior pituitary hyperintense signal was observed with (n = 2) and without (n = 1) structural hypothalamic pituitary abnormalities, and with no other underlying cerebral malformations. Patients with permanent CDI with persistent adipsia (n = 4) and without adipsia (n = 5) required adequate fluid intake and various doses of desamino-D-arginine-8-vasopressin. Those with adipsia were more likely to develop hypernatremia (45 vs 33%), hyponatremia (16 vs 4%) (P < .0001), and severe neurodevelopmental delay (P < .05) than those without adipsia. Comorbidities were common. The underlying cause remains unknown at the age of 23 years for one patient with CDI and normal thirst.

CONCLUSION

Neonatal CDI may be transient or permanent. These vulnerable patients have high rates of comorbidity and require careful monitoring.

Treatment of hypopituitarism in patients receiving antiepileptic drugs

Evidence suggests that there may be drug interactions between antiepileptic drugs and hormonal therapies, which can present a challenge to endocrinologists dealing with patients who have both hypopituitarism and neurological diseases. Data are scarce for this subgroup of patients; however, data for the interaction of antiepileptic drugs with the pituitary axis have shown that chronic use of many antiepileptic drugs, such as carbamazepine, oxcarbazepine, and topiramate, enhances hepatic cytochrome P450 3A4 (CYP3A4) activity, and can decrease serum concentrations of sex hormones. Other antiepileptic drugs increase sex hormone-binding globulin, which reduces the bioactivity of testosterone and estradiol. Additionally, the combined oestrogen-progestagen contraceptive pill might decrease lamotrigine concentrations, which could worsen seizure control. Moreover, sex hormones and their metabolites can directly act on neuronal excitability, acting as neurosteroids. Because carbamazepine and oxcarbazepine can enhance the sensitivity of renal tubules, a reduction in desmopressin dose might be necessary in patients with central diabetes insipidus. Although the effects of antiepileptic drugs in central hypothyroidism have not yet been studied, substantial evidence indicates that several antiepileptic drugs can increase thyroid hormone metabolism. However, although it is reasonable to expect a need for a thyroxine dose increase with some antiepileptic drugs, the effect of excessive thyroxine in lowering seizure threshold should also be considered. There are no reports of significant interactions between antiepileptic drugs and the efficacy of human growth hormone therapy, and few data are available for the effects of second-generation antiepileptic drugs on hypopituitarism treatment.

Surgery for pediatric craniopharyngiomas: is less more?

Surgery for craniopharyngiomas, especially in childhood and adolescence, has evolved from an era of aggressive strategies - with the primary goal of gross total removal and accepting an impaired functional outcome - to a more individually tailored therapy that avoids immediate treatment-related and long-term morbidity. Modern imaging techniques and a wider understanding of hypothalamic risk factors have led to surgical strategies adapted to the localization of these inhomogenously grown pathologies. Whereas purely infradiaphragmatic as well as supradiaphragmatic/infrachiasmatic tumors have a favorably surgical outcome with higher gross total resection rates in experienced hands, lesions within the third ventricle extending beyond the mammillary bodies remain a problem. The same is valid for lesions beyond 3 cm in diameter, more or less independent of their localization. Aside from the traditional microscopic approach via the subfrontal or pterional craniotomy, transsphenoidal approaches and other minimal invasive surgical methods, e.g., catheter implantation into cystic formations of the tumor have become popular. Radiotherapy, with its risks and limitations, can effectively be added to avoid recurrences. Nowadays, surgery as part of an interdisciplinary treatment strategy is still the typical first choice. However, taking the patient's long-term prognosis into considertaion, the surgical complication rates have to be minimized.

Efficacy of Hydrochlorothiazide and low renal solute feed in Neonatal Central Diabetes Insipidus with transition to Oral Desmopressin in early infancy

BACKGROUND

The treatment of central diabetes insipidus (DI) with desmopressin in the neonatal period is challenging because of the significant risk of hyponatremia with this agent. The fixed anti-diuresis action of desmopressin and the obligate high fluid intake with milk feeds lead to considerable risk of water intoxication and hyponatremia. To reduce this risk, thiazide diuretics, part of the treatment of nephrogenic DI, were used in conjunction with low renal solute feed and were effective in a single case series of neonatal central DI.

AIM

We evaluated the efficacy of early treatment of neonatal central DI with hydrochlorothiazide with low solute feed and investigated the clinical indicators for transition to desmopressin during infancy.

METHODS

A retrospective chart review was conducted at Princess Margaret Hospital, Perth of neonates diagnosed with central DI and treated with hydrochlorothiazide, between 2007 and 2013. Four newborns were identified. Mean sNa and mean change in sNa with desmopressin and hydrochlorothiazide treatment were recorded along with episodes of hyponatremia and hypernatremia. Length and weight trajectories during the first 12 months were assessed.

RESULTS

The mean change in sNa per day with hydrochlorothiazide and low renal solute feed was 2.5 - 3 mmol/L; on desmopressin treatment, the mean change in sNa was 6.8-7.9 mmol/L. There was one episode of symptomatic hyponatremia with intranasal desmopressin with no episodes of hyponatremia or hypernatremia during treatment with hydrochlorothiazide or following transition to oral desmopressin. Transition to oral desmopressin between 3 to 12 months of age was associated with good control of DI. Following introduction of solids, sNa remained stable but weight gain was slow. This improved following transition to desmopressin in one infant.

CONCLUSIONS

Hydrochlorothiazide with low renal solute feed is a safe and effective treatment option in neonatal central DI. However, transition to desmopressin should be considered early in infancy following initiation of solids to facilitate growth.

Clinical characteristics and management of cranial diabetes insipidus in infants

AIM

Cranial diabetes insipidus (CDI) is rare in infants with no guidelines on its management. We describe the first case series, characterizing the clinical features and treatment challenges.

METHOD

Retrospective case note review of infants diagnosed with CDI between April 1992 and February 2011.

RESULTS

Nineteen infants (52% male) were identified. Eight were born preterm. Median (range) age at diagnosis was 24 days (5-300); preterm babies were younger at diagnosis (21 vs. 46 days). In 58% (11/19) of infants, hypernatraemia was discovered incidentally. In 37% of cases there was associated midline anomalies, however, only four patients (21%) had absent posterior pituitary signal on a magnetic resonance imaging brain scan. The most frequent (5/19) underlying diagnosis was septo-optic dysplasia. Eight patients had isolated CDI and 11 had multiple pituitary hormone deficiencies. Isolated CDI tended to be more common in preterm, compared to term babies (p=0.11). Des-amino arginine vasopressin (DDAVP) was administered intranasally in eight and orally in 11 infants. Plasma sodium nadir following DDAVP administration was lower following intranasal compared to an oral route of administration (median: 128 vs. 133 mmol/L, p=0.022). No cases resolved on follow-up.

CONCLUSIONS

CDI in infants is often diagnosed incidentally. Aetiology, clinical, and imaging features are very variable, with some differences between preterm and term infants. Oral DDAVP appears to be superior to intranasal with less pronounced serum sodium fluctuations.

Prenatal presentation of transient central diabetes insipidus

INTRODUCTION

Nephrogenic diabetes insipidus (DI) in the foetus has been described as a rare presentation of severe polyhydramnios.

DISCUSSION

We report a case of foetal central DI, characterised by severe polyhydramnios. Significant polyuria was noted at birth. Serum AVP level was un-measurable (<0.5 pg/ml). A dramatic response to intravenous dDAVP (desmopressin) was noted confirming central DI. Further investigations did not reveal a recognised cause for central or nephrogenic DI. The infant thrived well on a small dose of oral desmopressin until the age of 12 months. At 13 months, a water deprivation test revealed a normal ability to concentrate urine without desmopressin, and subsequently, the infant has thrived without further treatment. The transient nature of the central DI remains obscure but could be explained by a maturational delay in the tissues involved in AVP synthesis or release, during intrauterine life and infancy.

CONCLUSION

Both nephrogenic and central DI should be considered as a cause of severe polyhydramnios. This may help to guide prompt intensive management and investigation, with attention to vascular access, central venous pressure, urine output monitoring and replacement.

Use of subcutaneous DDAVP in infants with central diabetes insipidus

Traditional methods for treating central diabetes insipidus during infancy, such as fluid therapy or the use of intranasal hormone replacement, have significant potential limitations. In a retrospective study of infants with diabetes insipidus, we examined outcome using subcutaneous (sc) DDAVP, and compared this to infants treated with intranasal lysine vasopressin or DDAVP. After in-patient dosage titration, outpatients' serum sodium concentrations were maintained in a narrower range in the sc group compared with the intranasal group, and the percentage of serum sodium concentrations within the normal range was greater in the sc group. There were no significant complications in either group. We conclude that DDAVP administered subcutaneously can be a safe and effective alternative to traditionally recommended treatments of central diabetes insipidus during infancy.

Morbidity and mortality associated with vasopressin analogue treatment

DDAVP is a drug that should be used with caution for each patient individually. Particular care is needed to avoid fluid overload and rapid fluctuations in sodium concentration. Not only families but physicians as well should be educated and aware of the adverse effects of DDAVP, especially in high risk patients. Extreme caution is needed in children with severe neurological and developmental problems who cannot control their fluid intake themselves. Similarly, caution is needed in patients with hypodipsia and DI who have difficulty in balancing water intake and DDAVP dose. The treatment of DI is water; however, DDAVP is given to avoid a large fluid intake which can result in medullary washout. Frequent home monitoring of body weight and regular determinations of serum sodium may help to disclose the early phase of over-hydration or dehydration. DDAVP therapy should be temporarily interrupted during acute illness, febrile episodes, hot days and other conditions with increased water intake. It should be used with considerable caution in patients with cystic fibrosis, or renal or cardiovascular diseases. In patients with enuresis, it is recommended that DDAVP medication should not be continued for longer than 3 months without stopping for 1 week for full reassessment. Fluid intake should be limited 1 hour before and 8 hours after the dose. Generally, undertreatment with vasopressin analogue is safer than overtreatment. A simple measure to avoid overtreatment is to miss one dose once a week; a rapid onset diuresis ('washout' effect) provides considerable reassurance.

Clinical observations of the effect of antidiuretic hormone on nocturia in elderly men

OBJECTIVE

To evaluate the effect of desmopressin on nocturia, based on patients' subjective scoring of nocturia, as desmopressin is widely used to treat nocturnal enuresis and nocturnal polyuria.

PATIENTS AND METHODS

We investigated a specific subgroup of 28 men with benign prostate obstruction and nocturia who were treated with desmopressin. Patients with nocturnal polyuria were excluded. All the patients were refractory to treatment with antimuscarinics or anticholinergics, e.g. oxybutynin, tolterodine, and propantheline bromide. We assessed the effect of desmopressin using a quantitative nocturia score and analysed its synergistic effect with alpha-blockers.

RESULTS

The mean frequency of nocturia was 6.1 before desmopressin and most (86%) patients had an improvement in nocturia within 1-12 weeks of treatment with desmopressin. There was a 43% reduction in nocturia after using desmopressin (P < 0.001). The correlation coefficient between the number of nocturnal voids and the reduction in nocturia after treatment with desmopressin was 0.756, indicating that the more severe the nocturia, the more effective was desmopressin.

CONCLUSIONS

Desmopressin is effective for refractory nocturia in elderly men with no nocturnal polyuria, and has limited side-effects.

Desmopressin associated symptomatic hyponatremic hypervolemia in children. Are there predictive factors?

PURPOSE

Desmopressin is widely used in primary nocturnal enuresis, bleeding disorders, central diabetes insipidus and diagnostic urine concentration testing. Hyponatremic hypervolemia leading to seizures has been reported as a rare but potentially life threatening side effect of desmopressin therapy. We sought to identify factors that predispose patients to hyponatremia and to find predictive factors associated with increased risk of water intoxication.

MATERIALS AND METHODS

We report 13 novel cases of desmopressin associated water intoxication and review the literature. A total of 93 instances of symptomatic hyponatremia during desmopressin treatment in children were identified. Specific data were reported in 58 of 93 cases. These 58 cases, in addition to our 13 novel cases, were further analyzed.

RESULTS

All children were treated with intranasal or intravenous desmopressin. No patient received oral desmopressin. Younger children are at greater risk for water intoxication than older children. The risk is particularly high at the beginning of desmopressin therapy. A total of 45 patients (63%) had prodromal symptoms, eg nausea, vomiting and headache. In 10 cases (14%) desmopressin was prescribed without an evident need.

CONCLUSIONS

Based on this analysis, we conclude that the use of desmopressin should be cautiously considered, careful monitoring should be performed during the initiation of therapy, and particular care should be taken when treating young children and when prodromal symptoms such as nausea, vomiting and headaches occur.

Nephrolithiasis complicating treatment of diabetes insipidus

A decrease in urine volume is considered the therapeutic goal of the treatment of central diabetes insipidus (DI) with desmopressin (dDAVP). A low urine volume is a risk factor for kidney stone formation. This is the first report of nephrolithiasis in association with DI. It is likely that successful therapy with dDAVP and the patient's own purposeful decreased fluid intake contributed to calcium oxalate stone formation. Prevention of stone recurrence requires an increase in urine volume. The patient's compliance with this recommendation led to an episode of acute hyponatremia, a well-known complication of dDAVP therapy. The challenge of the management of stones in the setting of DI requires balancing the conflicting goals of both decreasing and increasing urine volume.

Diabetes insipidus in children: pathophysiology, diagnosis and management

In diabetes insipidus, the amount of water ingested and the quantity and concentration of urine produced needs to be carefully regulated if fluid volume and osmolality are to be maintained within the normal range. One of the principal mechanisms controlling urine output is vasopressin which is released from the posterior pituitary gland and enhances water reabsorption from the renal collecting duct. In diabetes insipidus, the excessive production of dilute urine, and the causes of this clinical picture can be divided into three main groups: the first is primary polydipsia where the amount of fluid ingested is inappropriately large; the second group is cranial diabetes insipidus where the production of vasopressin is abnormally low; and, the third group is nephrogenic diabetes insipidus where the kidney response to vasopressin is impaired. The history and examination may suggest an underlying explanation for diabetes insipidus but a range of baseline and more extensive investigations may be required before a diagnosis can be reached. These investigations are not without risk, and the results need to be interpreted carefully because children do not always segregate neatly into a particular diagnostic category on the basis of one test alone. Children with cranial diabetes insipidus typically respond to arginine vasopressin or its manufactured analogue, desmopressin, with an increase in urine osmolality and an associated reduction in urine output. Such children usually require neuroimaging to look for evidence of evolving CNS pathology, such as an intracranial tumour. Vasopressin "replacement" with desmopressin is the treatment of choice in patients with cranial diabetes insipidus although extreme caution is required when treating babies or small children because of the danger of fluid overload. Abnormal production of other pituitary hormones in children with CNS disease can also influence fluid balance. Nephrogenic diabetes insipidus can be due to abnormal electrolyte concentrations, therefore these should be measured as part of the initial assessment. In a small number of children the defect is a primary abnormality of the vasopressin receptor or one of the water channel proteins (aquaporins) involved in water transport. The treatment of these patients is difficult and typically involves therapy with a diuretic such as chlorothiazide, as well as indomethacin. These agents enhance urine osmolality by their effect on circulating volume and renal solute and water handling. The fluid intake of most young children with primary polydipsia can be safely reduced to a more appropriate level.

Home sodium monitoring in patients with diabetes insipidus

OBJECTIVE

To determine whether home care givers can accurately measure plasma sodium in children with diabetes insipidus (DI) by using an I-STAT portable clinical analyzer (PCA) and to collect preliminary data on home PCA use.

STUDY DESIGN

Care givers of 4 children with DI and impaired thirst or inability to access water freely were instructed in PCA use. During an initial preclinical phase, the accuracy of sodium concentration measured by care givers was assessed by comparison to simultaneous analysis in a clinical laboratory. Participants were subsequently randomly assigned to daily home PCA monitoring or routine care. All participants crossed over from their original randomized group assignment to the alternate group.

RESULTS

After a single education session, all care givers were able to perform PCA testing. There was good correlation between PCA and laboratory sodium (r = 0.92). On the basis of Error Grid Analysis, use of the PCA sodium would have resulted in treatment decisions identical to those made based on the laboratory sodium value in 62 of 66 instances. Four minor differences in treatment would have occurred. There was no statistically significant difference in clinical outcome during daily monitoring versus routine care.

CONCLUSIONS

Results obtained by care givers using the PCA are sufficiently reliable for assessment of fluid status and making treatment decisions.