SOCIETY FOR ENDOCRINOLOGY CLINICAL GUIDANCE: Inpatient management of cranial diabetes insipidus

Introduction

Cranial diabetes insipidus (CDI) is due to the relative or absolute lack of the posterior pituitary hormone vasopressin (AVP), also known as anti-diuretic hormone (ADH). AVP is the major determinant of renal water resorption. AVP deficiency results in uncontrolled diuresis. Complete deficiency can lead to polyuria exceeding 10 L/24 h. Given a functioning thirst mechanism and free access to water, patients with CDI can normally maintain adequate fluid balance through increased drinking. Desmopressin (DDAVP, a synthetic AVP analogue) reduces uncontrolled water excretion in CDI and is commonly used in treatment. Critically, loss of thirst perception (through primary pathology or reduced consciousness) or limited access to water (through non-availability, disability or inter-current illness) in a patient with CDI can lead to life-threatening dehydration. This position can be further exacerbated through the omission of DDAVP. Recent data have highlighted serious adverse events (including deaths) in patients with CDI. These adverse outcomes and deaths have occurred through a combination of lack of knowledge and treatment failures by health professionals (1).

Scope of guidance

This guidance is for health care professionals with a role in the care of patients admitted to hospital, intermediate or supported care facilities. It covers the management of adult patients with established CDI. It does not cover the initial diagnosis of CDI, peri-operative management of CDI following pituitary surgery or the treatment of CDI in pregnancy. Important aspects of the decision making process during the management of inpatients with CDI are summarized in Figure 1.

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Important aspects in decision making during the management of inpatients with cranial diabetes insipidus.

Citation: Endocrine Connections 7, 7; 10.1530/EC-18-0154

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Aetiology of CDI and important associated comorbidities

CDI can occur in isolation. However, CDI is commonly found in the context of wider hypopituitarism or indeed as part of a more complex neurodevelopmental or acquired neurological/post-neurosurgical clinical problem (2). Patients with CDI may thus have a range of comorbidities (sensory, motor, communication and cognitive) impacting directly and indirectly on their ability to manage fluid balance and medication independently, especially in an environment with which they are not familiar.

Patients with CDI who require hydrocortisone, prednisolone or other glucocorticoid replacement because of wider hypopituitarism require increased doses and/or parenteral administration in the acute setting during inter-current illness (3). Glucocorticoids enable renal free water excretion. If an acute inter-current illness renders a patient unable to give a history of pre-existing CDI, the problem may only become apparent to the clinician after parenteral glucocorticoid administration.

Given the importance of an intact thirst mechanism in enabling maintenance of fluid balance, patients with adipsia and CDI are particularly vulnerable. Some patients with adipsic CDI have continuous, low level, non-osmoregulated AVP production. This group of patients are thus at risk of both dehydration with hypernatraemia and dilutional hyponatraemia if fluid intake is not managed appropriately (4).

Risk assessment and risk stratification

Certain patient groups with CDI are at particular risk of rapid deterioration (Box 1).

Desmopressin preparations

Desmopressin comes in the form of tablets, intranasal spray and solution, sublingual preparations and injectable forms (Table 1).

Organisational guidance for hospitals and other care facilities

The approach to patients who are able to drink or require maintenance intravenous fluid therapy and care able to take DDAVP

The approach to patients with impaired consciousness or who are unable to manage own fluid intake and medication

The approach to patients who are significantly unwell with inter-current illness or decompensated CDI

Declaration of interest

The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of this guideline.

Funding

This work did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.

Disclaimer

The document should be considered as a guideline only. It is not intended to determine an absolute standard of medical care. The doctor concerned must make the management plan for the individual patient.