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Would a new definition and classification of nocturia and nocturnal polyuria improve our management of patients? ICI-RS 2014.
By J.R. Bosch, K. Everaert, J.P. Weiss, H. Hashim, M.S. Rahnama'I, A.S. Goessaert, and J. Aizen.
Neurourology and Urodynamic, Article first published online: 10 APR 2015, DOI: 10.1002/nau.22772
The Nocturia Think-Tank Panel (TTP) of the 2014 Meeting of the International Consultation on Incontinence—Research Society, which took place September 22–24, 2014 in Bristol, UK, tried to to answer the following research question: “Would a new definition and classification of nocturia and nocturnal polyuria improve our patients’ management?” The TTP explored the current literature in order to reconsider and suggest proposals for further research to reach more practical and more clinically meaningful definitions.
Current definition of nocturia: “Nocturia is the complaint that the individual has to wake at night one or more times to void.” The current definition takes into consideration the bother that the individual has due to nocturia. Recent literature suggests a close relationship between nocturia severity (3–4 voids per night) and mortality and this symptom may be the consequence of a serious non-urological disease, such as heart failure, diabetes mellitus, sleep apnoea, diabetes insipidus and nephrotic syndrome. The TTP suggests that severe nocturia should be considered and evaluated regardless of bother. Indeed, to improve the definition of nocturia one should take into consideration the severity of the symptom (that may or may not be bothersome) and other elements such as age and gender. In this respect, the evaluation of the etiology of nocturia is a crucial factor to determine the most adequate treatment.
Definition of nocturnal polyuria: “Nocturnal polyuria is present when an increased proportion of the 24 hour output occurs at night (normally during the 8 hours that the patient spends in bed) The nighttime urine output excludes the last void before sleep but includes the first void of the morning. The nocturnal urine volume (NUV) is currently defined as the total volume of urine passed between the time the individual goes to bed with the intention of sleeping and the time of waking with the intention of rising. In the measurement of NUV, the last voiding before going to bed is excludeed and the first voiding of the morning is included. This leads to misclassification because part of the first volume voided at night is produced before going to bed and part of the first morning void is not produced before getting up in the morning. It should be very important to recognize if this misclassification has an impact on diagnosis and treatment of nocturia.
Other considerations are made by the TTP. The current definition of nocturnal polyuria shows some confusing concepts: if an individual has a good bladder capacity, he or she may not even have to get up to void at night. It means that some individuals with nocturnal polyuria do not present with nocturia. In addition, nocturnal polyuria and the 24 hour polyuria have different units (ratio or % versus volume per time unit), thus they cannot be mathematically compared.
The panelists suggested that new definitions of nocturia and nocturnal polyuria should be tested against new measurements for nocturnal polyuria, such as the kidney function profile. In addition, they propose new fields of research to test new definitions against prevalence, micturition diaries and symptoms.
The following is a report of the proceedings of the Nocturia Think Tank sessions of the annual International Consultation on Incontinence-Research Society, which took place September 22-24, 2014 in Bristol, UK. The report is organized into sections pertaining to the main topic of discussion focussing on the question as to whether a new definition and classification of nocturia and nocturnal polyuria would improve the outcome ofmanagement in our patients. First, discussions identified theoretical and practical shortcomings of current definitions. Secondly, the utility of severalnocturnal polyuria definitions was tested in a real life population in relation to the symptom nocturia, in order to display weaknesses of these definitions. Thirdly, we explored in a clinical population the utility of bladder diary based parameters by asking the question: when nocturia improves, which of these parameters improve most? Based on the above explorations the Think Tank summarized elements of the current definitions that need reconsideration and suggests proposals for further research to reach more practical and more clinically meaningful definitions.