Time for change: Renaming Diabetes Insipidus to improve patient safety

Abstract

Diabetes Insipidus (DI) is a name given historically to two conditions, which result in “diabetes,” which is Greek for “syphon” or polyuria. The “Insipidus” refers to urine being insipid. “Cranial DI” is so called because it relates to a cause within the head characterized by deficiency of vasopressin [antidiuretic hormone (ADH)] secretion from the posterior pituitary. Treatment is with desmopressin, a synthetic long-acting analogue of vasopressin. In contrast, “Nephrogenic DI” is due to resistance of the renal tubules to vasopressin action. The term “DI” distinguishes it from diabetes mellitus (DM), which describes polyuria with sweet urine. Over several decades, the word “diabetes” has become synonymous with “Diabetes Mellitus” in most lay and nonendocrine medical arenas. The problem of “DI” terminology is painfully illustrated by a tragic and avoidable death. In 2009, a 22-year-old man was admitted to a London teaching hospital for an elective hip replacement. He was fit and well but was pan anterior and posterior hypopituitary requiring full replacement therapy, including desmopressin, after successful treatment for a suprasellar germinoma the previous year. Treatment for the germinoma with high-dose glucocorticoid therapy had caused avascular necrosis of his hip. A pre-admission assessment had recommended that the endocrine team in the hospital be informed on his admission. On admission to the orthopaedic ward, his drug card was completed with the appropriate pituitary hormone replacement therapy including desmopressin, but the endocrine team was not informed. Although the hip operation the next day was without incident, back on the ward, he became confused. His mother told the ward staff that “he gets like this when he doesn't take his medication.” The following day, he was even more confused and the ward staff found his condition challenging. A psychiatric opinion was sought as he had a history of previous marijuana use. Various options to sedate him were suggested. He was put in a sideward. At this stage, the patient himself called the police by phone and pleaded for help as “I am so thirsty and they are not giving me anything to drink.” The police came to the ward, but were reassured by the ward staff and left. His blood sugar and electrolytes were taken, and although the glucose was normal, the serum sodium was 149 mmol/L. A medical review was requested but did not happen. At just after 09:00 hours, the next morning, the patient had a fatal cardiac arrest with a serum sodium of 169 mmol/L. The Coroner's inquest highlighted the failure to inform the endocrine team on admission and concluded that neither the doctors, nor nurses, nor pharmacists on the ward understood the complexity of the patient's medical condition. No desmopressin had been administered to the patient for 48 hours since his admission. The Coroner summarized the death was due to “dehydration contributed to by neglect.”1 The legal case for this young man ended in 2012. In February 2016, NHS England sent an alert to all doctors informing them of the risk of omitting life-sustaining medication.2 It quoted evidence from NHS England and from the National Reporting and Learning System (NRLS) that from 2009 to 2015, and there had been 471 incidents involving desmopressin. Of these, the wrong dose (n = 56) and omission (n = 76) were the commonest errors. Four of these omissions had resulted in death from severe dehydration. The NHS Alert recommended that measures be put in place in all hospitals to avoid the omission of life-sustaining therapy. One means to avoid this catastrophe is an educational programme in all hospitals, and, where electronic prescribing systems are in place, a mandatory flag is placed for desmopressin with warnings that this is a life-sustaining therapy and must never be omitted, and supplies must be obtained immediately, or a doctor called. (We have also flagged all steroid and insulin prescriptions.) Another way to reduce the chance of failure of recognition of DI by staff and distinguish it from DM would be if the name was changed to avoid the word “diabetes.” Suggestions include use of the term “Pituitary Insipidus” for Cranial DI and “Renal Insipidus” for nephrogenic DI. An advantage of retaining the word “insipidus” would be to keep part of the original description and facilitate search library databases. The terms “Pituitary” and “Renal” would also inform which medical team to call. Whilst endocrinologists find no problem with the term DI, there is clear evidence of confusion and treatment failures, as highlighted in the safety alert.2 Renaming DI would help to inform all healthcare professionals and patients that this is a specialist life-sustaining therapy distinct from DM and that it needs to be continued in all situations with the assistance of endocrine teams. Whilst educating and upskilling the workforce to avoid serious untoward “never” events can be effective, a simple name change may offer patients a better chance of being managed more safely. Renaming a medical condition is not unheard of; for example, in the field of rheumatology, the name of a condition was removed in order to better describe the pathology and to remove an honorific eponym. (Wegener's Granulomatosis was changed to Granulomatosis with Polyangiitis).3 The father of the young man who died in 2009 was asked for his permission to use the story of his son's tragic death, in an attempt to avoid any recurrence, or at least to reduce the chance of death in the future for inpatients with DI. He has fully endorsed the idea of a name change and wished to add his support in any way possible, adding that he was surprised that the name had not been changed already.