Predictors of failure to respond to fluid restriction in SIAD in clinical practice; time to re-evaluate clinical guidelines?

BACKGROUND: Fluid restriction is recommended as first line therapy for Syndrome of Inappropriate Antidiuresis (SIAD), despite of lack of good evidence base to support its use, and poor efficacy in clinical practice and in the literature. AIM: We set out to determine how many patients with well-defined SIAD had pre-treatment criteria which would predict failure to fluid restriction. DESIGN AND METHODS: This was a consecutive, prospective evaluation of 183 patients with a diagnosis of SIAD in two different hospitals. Full ascertainment of the diagnostic criteria for SIAD was obtained in all patients. RESULTS: About 47% of patients had a urine volume <1500 ml in 24 h, 41% had initial urine osmolality > 500 mOsm/kg, 26% a Furst-equation ratio > 1. About 59% had one criterion predicting failure to respond to fluid restriction, 37% two criteria, and 3% three criteria. CONCLUSIONS: Our data suggest that up to 60% of patients with SIAD had criteria which recent clinical guidelines suggest would predict nonresponse to fluid restriction. This may explain why the recommended first line therapy for SIAD has been shown to be ineffective.

ANCA-associated vasculitis: a comparison of cases presenting to nephrology and rheumatology services.

BACKGROUND: Anti-neutrophil cytoplasmic antibody (ANCA) -associated vasculitis (AAV) is a disease characterized by inflammation of small vessels and detectable ANCA in the circulation. Patients may develop a broad spectrum of clinical features ranging from indolent sino-nasal disease and rashes to fulminant renal failure or acute life-threatening pulmonary haemorrhage. Consequently, patients with AAV present to a variety of specialties including nephrology and rheumatology, whose training and approaches to management of such patients may differ. There is little literature comparing patients presenting to different specialties and their outcomes. METHODS: We compared two cohorts of patients with ANCA-positive AAV presenting to either the rheumatology or nephrology department at Galway University Hospitals from June 2002 to July 2011. A standardized data collection form was used to collect information regarding baseline demographics, manifestations of AAV, initial management, relapses and complications. RESULTS: Forty-five patients were included in this study (15 rheumatology/30 nephrology). The nephrology cohort was older, had a higher C-reactive protein, Birmingham Vascular Activity Score and ANCA titer at presentation compared to the rheumatology group. Induction treatment varied between the cohorts with rheumatology patients most commonly receiving a combination of oral corticosteroids (73%) and methotrexate (60%) and nephrology patients receiving a combination of intravenous corticosteroids (93%) and cyclophosphamide (90%). Fifty-three percent of the rheumatology patients who completed induction therapy relapsed compared to 30% of the nephrology patients. CONCLUSION: This study presents two different cohorts of patients with the same disease that were managed by two different disciplines. It highlights the heterogeneity of AAV and the importance of interdisciplinary communication and cooperation when managing these patients.

SIAD: practical recommendations for diagnosis and management.

Hyponatremia is the commonest electrolyte disturbance encountered in hospitalized patients, and the syndrome of inappropriate antidiuresis (SIAD) is the most frequent underlying disorder. There is a well-recognized relationship between hyponatremia and increased morbidity and mortality. Therefore, to provide appropriate treatment is critical to improve the clinical outcome related to SIAD-hyponatremia. There have been important advances in the treatment of SIAD over the last decade, leading to the publication of several clinical guidelines. In particular, the introduction of the vasopressin-2 receptor antagonists provides a potent pharmacological tool to target the underlying pathophysiology of SIAD. The evidence base recommendations of the available therapies for SIAD are discussed in this study. Fluid restriction is considered the first-line therapy by the recent published guidelines, but it is certainly ineffective or unfeasible in many patients with SIAD. We discuss a number of relevant points to the use of fluid restriction in this study, including the lack of good evidence-based recommendations to support its use. Conversely, the clinical efficacy of oral tolvaptan in SIAD supported by good quality randomized, placebo controlled, clinical trials. However, the cost of the therapy and the need for long-term safety data may limit its widespread use. Finally, new recommendations for the management of acute hyponatremia with a focus on the use of bolus therapy with 3 % hypertonic sodium chloride are described in this study.

A review of the management of positive biochemical screening for phaeochromocytoma and paraganglioma: a salutary tale.

BACKGROUND: Phaeochromocytomas (PC) and paragangliomas (PGL) are rare neuroendocrine tumours of chromaffin cells. Diagnosis depends on biochemical evidence of excessive production of catecholamines. This is straightforward when test results are orders of magnitude above the concentrations expected in healthy individuals and those with essential hypertension. Equivocal results pose a management dilemma. AIM: We reviewed biochemical screens that were positive and the ensuing management for PC/PGL at our institution. The objective was to inform the development of a standardised approach to investigation and clinical follow-up. METHOD: All records of positive biochemical screening for PC/PGL were extracted from the laboratory information system between January 2004 and June 2012. Clinical notes of patients with positive results were reviewed. RESULTS: A total of 2749 biochemical screens were performed during the evaluation period. Of these, 106 (3.9%) performed on 82 patients were positive. Chart review determined that 12/82 patients had histologically confirmed PC/PG. Of the 70 patients remaining, the most common indication for biochemical screening was hypertension and the medical subspecialty most frequently requesting the test was Endocrinology. The primary team carried out repeat testing on 35/70 (50%) patients and in 29 results normalised. Notably, 35/70 (50%) patients did not have any follow-up of positive test results. CONCLUSION: This study highlights the necessity for a standardised diagnostic protocol for PC/PGL. We suggest that appropriate follow-up of borderline-elevated results should first include repeat biochemical testing. This should be performed under standardised pre-analytical conditions and where possible off all potentially interfering medications, measuring plasma free metadrenalines.

Validation of a vision-based, three-dimensional facial imaging system.

OBJECTIVE: The aim of this study was to assess the accuracy of a newly developed three-dimensional (3D) imaging system in recording facial morphology. METHODS: Twenty-one infants with cleft lip each had a full-face alginate impression taken at the time of primary lip repair, and a stone cast was constructed from each impression. Five anthropometric points were marked on each cast. Each cast was digitized, and the 3D co-ordinates of the five points were obtained using a co-ordinate measuring machine (CMM, Ferranti) of documented accuracy (9.53 microm). Each cast was scanned in four positions using a computerized stereophotogrammetry (C3D) system. The five points were located on the 3D images, and their 3D co-ordinates were extracted by three operators. The co-ordinate systems produced by C3D were aligned, via translation and rotation, to match the CMM co-ordinate system using partial ordinary procrustes analysis. The displacements of the adjusted C3D co-ordinates from the reference co-ordinates were then measured. Three different types of errors were identified: operator, system, and registration errors. RESULTS: Operator error was within 0.2 mm of the true co-ordinates of the landmarks. C3D was accurate within 0.4 mm. The average displacement of points over the 21 casts at four positions for the three operators was 0.79 mm (median 0.68). CONCLUSIONS: The presented 3D imaging system is reliable in recording facial deformity and could be utilized in recording cleft deformities and measuring the changes following surgery