A Multicenter, Propensity Score-Matched Assessment of Endoscopic Versus Microscopic Approaches in the Management of Pituitary Adenomas.

BACKGROUND AND OBJECTIVES: There is considerable controversy as to which of the 2 operating modalities (microsurgical or endoscopic transnasal surgery) currently used to resect pituitary adenomas (PAs) is the safest and most effective intervention. We compared rates of clinical outcomes of patients with PAs who underwent resection by either microsurgical or endoscopic transnasal surgery. METHODS: To independently assess the outcomes of each modality type, we sought to isolate endoscopic and microscopic PA surgeries with a 1:1 tight-caliper (0.01) propensity score-matched analysis using a multicenter, neurosurgery-specific database. Surgeries were performed between 2017 and 2020, with data collected retrospectively from 12 international institutions on 4 continents. Matching was based on age, previous neurological deficit, American Society of Anesthesiologists (ASA) score, tumor functionality, tumor size, and Knosp score. Univariate and multivariate analyses were performed. RESULTS: Among a pool of 2826 patients, propensity score matching resulted in 600 patients from 9 surgery centers being analyzed. Multivariate analysis showed that microscopic surgery had a 1.91 odds ratio (OR) ( P = .03) of gross total resection (GTR) and shorter operative duration ( P < .01). However, microscopic surgery also had a 7.82 OR ( P < .01) for intensive care unit stay, 2.08 OR ( P < .01) for intraoperative cerebrospinal fluid (CSF) leak, 2.47 OR ( P = .02) for postoperative syndrome of inappropriate antidiuretic hormone secretion (SIADH), and was an independent predictor for longer postoperative stay (ß = 2.01, P < .01). Overall, no differences in postoperative complications or 3- to 6-month outcomes were seen by surgical approach. CONCLUSION: Our international, multicenter matched analysis suggests microscopic approaches for pituitary tumor resection may offer better GTR rates, albeit with increased intensive care unit stay, CSF leak, SIADH, and hospital utilization. Better prospective studies can further validate these findings as matching patients for outcome analysis remains challenging. These results may provide insight into surgical benchmarks at different centers, offer room for further registry studies, and identify best practices.

Chloride and Potassium Assessment Is a Helpful Tool for Differential Diagnosis of Thiazide-Associated Hyponatremia.

CONTEXT: Differential diagnosis of thiazide-associated hyponatremia (TAH) is challenging. Patients can either have volume depletion or a syndrome of inappropriate antidiuresis (SIAD)-like presentation. OBJECTIVE: To evaluate the impact of the simplified apparent strong ion difference in serum (aSID; sodium + potassium - chloride) as well as the urine chloride and potassium score (ChU; chloride - potassium in urine) in the differential diagnosis of TAH, in addition to assessment of fractional uric acid excretion (FUA). METHODS: Post hoc analysis of prospectively collected data from June 2011 to August 2013 from 98 hospitalized patients with TAH < 125 mmol/L enrolled at University Hospital Basel and University Medical Clinic Aarau, Switzerland. Patients were categorized according to treatment response in volume-depleted TAH requiring volume substitution or SIAD-like TAH requiring fluid restriction. We computed sensitivity analyses with ROC curves for positive predictive value (PPV) and negative predictive value (NPV) of aSID, ChU, and FUA in differential diagnosis of TAH. RESULTS: An aSID > 42 mmol/L had a PPV of 79.1% in identifying patients with volume-depleted TAH, whereas a value < 39 mmol/L excluded it with a NPV of 76.5%. In patients for whom aSID was inconclusive, a ChU < 15 mmol/L had a PPV of 100% and a NPV of 83.3%, whereas FUA < 12% had a PPV of 85.7% and a NPV of 64.3% in identifying patients with volume-depleted TAH. CONCLUSION: In patients with TAH, assessment of aSID, potassium, and chloride in urine can help identifying patients with volume-depleted TAH requiring fluid substitution vs patients with SIAD-like TAH requiring fluid restriction.

A Nationwide Analysis of Aneurysmal Subarachnoid Hemorrhage Mortality, Complications, and Health Economics in the USA.

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating neurological condition. Endovascular coiling or surgical clipping have equivocal success rates, but relatively little is known regarding the health economics and complications of these procedures at the population level. We aimed to analyze the complication profiles and healthcare resource utilization (HRCU) associated with the treatment of aSAH in the USA. We performed a retrospective analysis utilizing the IBM MarketScan database between 2008 and 2015. Primary outcomes included economic analysis stratified by post-operative complication; determination of the effect of several factors on total cost by multivariable regression; and analysis of the incidence, timing, and associated HCRU of aSAH-related post-operative complications. Of the 2374 patients meeting inclusion criteria for economic analysis, 1783 (75.1%) patients had at least one of the ten complications. The most common complications included hydrocephalus (43.8%), transient cerebral ischemia (including vasospasm) (30.6%), ischemic stroke (29.1%), syndrome of inappropriate antidiuretic hormone (SIADH)/hyposmolarity/hyponatremia (22.1%), and seizures (14.9%). Patients who experienced complications had higher median 90-day total costs [$161,127 (Q1 to Q3, $101,411 to $257,662)] than those who did not [$97,376 (Q1 to Q3, $55,692 to $147,447)]. Length of stay was longest for those with pulmonary embolism and pneumonia (27 days) and shortest for those with SIADH/hyposmolarity/hyponatremia (16 days). Brain compression/herniation had the highest mortality rate (19.5%). In total, 14.6% of all patients experienced a readmission within 30 days. In conclusion, patients with aSAH have high post-operative complication rates and costs. Development of novel interventions to reduce complications and improve outcomes is crucial.

Management of hyponatremia: causes, clinical aspects, differential diagnosis and treatment.

INTRODUCTION: Hyponatremia is the most frequent electrolyte disorder in hospitalised patients. Acute and severe hyponatremia may be a life-threatening situation. However, also mild and chronic hyponatremia may negatively affect the health status (i.e. gait disturbances, attention deficits, falls and fractures, and bone loss) and may increase the risk of death. Therefore, it is of paramount importance for clinicians to have an in-depth knowledge on this topic, in order to appropriately manage patients affected by hyponatremia. AREAS COVERED: This review will cover different areas related to this electrolyte disorder. Because many pathologic conditions may be associated with hyponatremia, thorough investigations have to be performed in order to establish the underlying etiology. To establish the cause of hyponatremia is of great importance, because an appropriate therapeutic strategy is strictly dependent on a correct diagnosis. A description of the different available therapeutic approaches for the correction of hyponatremia, including vaptans, will follow. EXPERT COMMENTARY: Undoubtedly, the studies that have been published in recent years and the introduction of vaptans in clinical practice have contributed to increase the awareness on hyponatremia among clinicians. Nevertheless, additional studies are needed in order to clarify some partially uncovered areas.

Recurrent Rathke's Cleft Cysts: Incidence and Surgical Management in a Tertiary Pituitary Center over 2 Decades.

BACKGROUND: Limited data exist pertaining to outcomes following surgery for recurrent Rathke's cleft cysts (RCC). OBJECTIVE: To determine treatment outcomes in patients undergoing reoperation for recurrent or residual RCCs. METHODS: A retrospective analysis of 112 consecutive RCC operations in 109 patients between 1995 and 2017 was conducted. RESULTS: Eighteen patients underwent 21 RCC reoperations with a mean follow-up of 58 mo. Patient symptoms prior to reoperation included headaches (14, 66.7%) and vision loss (12, 57.1%). Thirteen of 18 patients (72.2%) required hormone supplementation prior to reoperation including 5 with diabetes insipidus (DI). Mean RCC diameter was 16 mm and 76% had suprasellar extension. Compared to index RCC cases, intraoperative cerebrospinal fluid leak repair was more common in reoperation cases (15/21, 71% vs 43/91, 47%, P = .05). There was 1 carotid artery injury without neurological sequelae, and 2 postoperative cerebrospinal fluid (CSF) leaks (9.5%). Rates of transient hyponatremia (3/10, 30% vs 4/91, 4.4%, P = .04) and transient DI (5/10, 50% vs 17/91, 18.7%, P = .04) were higher in the reoperation vs index group. Improved headaches and vision were reported in 4/12 (33%) and 8/12 (61.5%) of RCC reoperation patients, respectively. Two patients developed new permanent DI. A higher proportion of reoperation patients had RCC squamous metaplasia (24% vs 5.4%, P = .02) or wall inflammation (42.9% vs 2.2%, P < .001) on pathological examination. CONCLUSION: Reoperation for RCCs is generally safe at tertiary pituitary centers and often results in improved vision. Hypopituitarism is less likely to improve following reoperation for recurrent RCCs. Several histopathological features may help characterize "atypical RCCs" with a higher likelihood of recurrence/progression.

An economic analysis of tolvaptan compared with fluid restriction among hospitalized patients with hyponatremia.

OBJECTIVE: The vasopressin-receptor antagonist tolvaptan is used for the treatment of hyponatremia (HN) in hospitalized patients with congestive heart failure (CHF) or syndrome of inappropriate antidiuretic hormone secretion (SIADH). The objective of this economic modeling study was to assess the potential cost and health outcomes associated with tolvaptan in comparison with fluid restriction (FR). METHODS: A decision-analytic model was developed to estimate potential cost and health outcomes associated with tolvaptan compared with FR among hospitalized CHF and SIADH patients with severe HN (serum sodium [SS] levels < 125 mEq/L). The model, which was populated with data from the published literature, assumes that response to treatment influences hospital length of stay, probability of an intensive care unit (ICU) admission, and probability of a 30-day all-cause hospital readmission. One-way and probabilistic sensitivity analyses (PSAs) assessed the influence of parameter uncertainty on model results. RESULTS: Model results suggest that, among hospitalized CHF patients with severe HN, the use of tolvaptan compared with FR may lead to reductions of 7.2% and 4.6% in ICU admissions and 30-day readmissions, respectively. Compared with FR, tolvaptan may result in total cost-savings of $156 per hospitalized CHF patient. Among hospitalized SIADH patients with severe HN, the model suggested reductions of 14.6% and 5.1% in ICU admissions and 30-day readmissions, respectively. Compared with FR, tolvaptan may result in total cost-savings of $135 per hospitalized SIADH patient. PSAs found that the probabilities of net cost-savings from the use of tolvaptan compared with FR were 64% and 59% among patients with severe HN with CHF and SIADH, respectively. CONCLUSIONS: Decision-analytic modeling based on published data for hospitalized CHF and SIADH patients with severe HN, indicates that tolvaptan compared with FR has the potential to improve health outcomes and produce cost-savings that more than offset the cost of tolvaptan.

The V2 receptor antagonist tolvaptan raises cytosolic calcium and prevents AQP2 trafficking and function: an in vitro and in vivo assessment.

Tolvaptan, a selective vasopressin V2 receptor antagonist, is a new generation diuretic. Its clinical efficacy is in principle due to impaired vasopressin-regulated water reabsorption via aquaporin-2 (AQP2). Nevertheless, no direct in vitro evidence that tolvaptan prevents AQP2-mediated water transport, nor that this pathway is targeted in vivo in patients with syndrome of inappropriate antidiuresis (SIAD) has been provided. The effects of tolvaptan on the vasopressin-cAMP/PKA signalling cascade were investigated in MDCK cells expressing endogenous V2R and in mouse kidney. In MDCK, tolvaptan prevented dDAVP-induced increase in ser256-AQP2 and osmotic water permeability. A similar effect on ser256-AQP2 was found in V1aR -/- mice, thus confirming the V2R selectively. Of note, calcium calibration in MDCK showed that tolvaptan per se caused calcium mobilization from the endoplasmic reticulum resulting in a significant increase in basal intracellular calcium. This effect was only observed in cells expressing the V2R, indicating that it requires the tolvaptan-V2R interaction. Consistent with this finding, tolvaptan partially reduced the increase in ser256-AQP2 and the water permeability in response to forskolin, a direct activator of adenylyl cyclase (AC), suggesting that the increase in intracellular calcium is associated with an inhibition of the calcium-inhibitable AC type VI. Furthermore, tolvaptan treatment reduced AQP2 excretion in two SIAD patients and normalized plasma sodium concentration. These data represent the first detailed demonstration of the central role of AQP2 blockade in the aquaretic effect of tolvaptan and underscore a novel effect in raising intracellular calcium that can be of significant clinical relevance.

Cost-effectiveness of tolvaptan for the treatment of hyponatraemia secondary to syndrome of inappropriate antidiuretic hormone secretion in Sweden.

BACKGROUND: Tolvaptan is the only vasopressin V2 receptor antagonist licensed by the European Medicines Agency for the treatment of hyponatraemia (HN) secondary to the syndrome of inappropriate antidiuretic hormone secretion (SIADH). We have investigated the cost-effectiveness of tolvaptan versus no active treatment (NAT) in adult patients within the licensed indication who have either failed to respond to fluid restriction or for whom the use of fluid restriction is not suitable, from the societal perspective in Sweden. METHODS: A cost-utility analysis, considering a 'general SIADH' population and two subpopulations of patients (small-cell lung cancer [SCLC] and pneumonia) to broadly represent the complex clinical pathway of SIADH, was performed. A discrete event simulation was developed to model the progression of individuals through inpatient admissions over a 30-day time horizon (180 days for the SCLC cohort). Clinical data were derived from tolvaptan trials and observational data sources. All costs are given in Swedish kronor (SEK). RESULTS: In the 'general SIADH' population, tolvaptan was associated with reduced costs (SEK 5,779 per patient [€624]) and increased quality-adjusted life-years (QALYs) (0.0019) compared with NAT and was therefore the dominant treatment strategy. Tolvaptan was also associated with reduced costs and increased QALYs in the SCLC and pneumonia subpopulations. The most influential variables in our analysis were reduction in hospital length of stay, duration of treatment and long term treatment with tolvaptan in SCLC patients. CONCLUSIONS: Tolvaptan represents a cost-effective treatment option in Sweden for hospitalised patients with HN secondary to SIADH who have either failed to respond to or are unsuitable for fluid restriction.

[Effectiveness and adequacy of tolvaptan prescription in hospitalized patients]. / Efectividad y adecuación de la prescripción de tolvaptán en pacientes hospitalizados.

PURPOSE: To analyse the effectiveness of the use of Tolvaptan and the adequacy of Tolvaptan prescription at a tertiary level hospital. METHODS: Prospective observational study of Tolvaptan prescrip - tion from October of 2010 to December of 2011. RESULTS: 30 patients (60.0% males) were included, 50.0% of which were diagnosed with heart failure and 30.0% with SIADH. Tolvaptan allowed achieving sodium levels higher than 135 mEq/L in 53.3% of the patients with a mean baseline value of 125.3±7.3 mEq/L. The median treatment duration was 5.0 days (interquartile range=3-45). A significant increase of uric acid associated to Tolvaptan treatment was observed. The prescription was in agreement to what has been established in GFT in 63.3% of the cases. CONCLUSIONS: Tolvaptan increases sodium levels by 7.5 mEq/L, both in SIADH-associated hyponatremia and in heart failure, with an appropriate safety profile.

Objetivo: Analizar la efectividad del uso de tolvaptán y la adecuación de su prescripción en un hospital de tercer nivel. Método: Estudio observacional prospectivo de las prescripciones de tolvaptán desde octubre de 2010 hasta diciembre de 2011. Resultados: Se incluyeron 30 pacientes (60,0% varones), 50,0% diagnosticados de insuficiencia cardíaca y 30,0% de SIADH. Tolvaptán permitió alcanzar niveles de sodio superiores a 135 mEq/L en el 53,3% de los pacientes que partían con una media de 125,3±7,3 mEq/L. La mediana de días de tratamiento fue de 5,0 (rango intercuartílico = 3-45). Se observó un incremento significativo de los niveles de ácido úrico asociado al tratamiento con tolvaptán. La prescripción se adecuó a lo establecido en la GFT en el 63,3% de los casos. Conclusiones: Tolvaptán incrementa un 7,5 mEq/L los niveles de sodio tanto en hiponatremia secundaria al SIADH como en insuficiencia cardiaca.

Perspectives on the management of hyponatraemia secondary to SIADH across Europe.

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is the most common cause of euvolaemic hyponatraemia. However, although first described over 50 years ago, the management of hyponatraemia secondary to SIADH is not always straightforward. Some of the issues surrounding the management of hyponatraemia secondary to SIADH were explored in the European Hyponatraemia Survey completed by attendees of the European Hyponatraemia Network Academy Meeting 2011. This article describes the findings of this survey and the specific issues raised regarding the management of hyponatraemia secondary to SIADH in Europe. Some of these issues - including awareness, education, diagnosis, management and cost considerations of the condition - were common to countries across Europe.

Evaluation of costs associated with tolvaptan-mediated hospital length of stay reduction among US patients with the syndrome of inappropriate antidiuretic hormone secretion, based on SALT-1 and SALT-2 trials.

BACKGROUND: Two randomized clinical trials, the Study of Ascending Levels of Tolvaptan in Hyponatremia 1 and 2 (SALT-1 and SALT-2), showed that tolvaptan was an efficacious and safe therapy for the treatment of hyponatremic patients with the syndrome of inappropriate antidiuretic hormone secretion (SIADH). HYPOTHESIS: This study evaluated the potential cost savings associated with tolvaptan usage based on the SALT-1 and SALT-2 trials. METHODS: Hospital length of stay (LOS) reduction associated with tolvaptan versus placebo was evaluated among hyponatremic patients with the SIADH (serum sodium < 135 mEq/L) from the combined data of the SALT-1 and SALT-2 trials. The Healthcare Cost and Utilization Project 2009 Nationwide Inpatient Sample database was used to estimate hospital cost and LOS for hospitalizations of adult (age ≥ 18 years) patients with the SIADH. A cost-offset model was constructed to evaluate the impact of tolvaptan on hospital cost and LOS, with univariate and multivariate Monte Carlo sensitivity analyses. RESULTS: In the SALT-1 and SALT-2 trials, patients with the SIADH receiving tolvaptan had a shorter hospital LOS than patients receiving placebo (4.98 vs 6.19 days, respectively). There were 21 718 hospitalizations for the SIADH identified from the Healthcare Cost and Utilization Project Nationwide 2009 Inpatient Sample database, with a mean LOS of 5.7 days and mean total hospital costs of $8667. Using an inpatient tolvaptan treatment duration of 4 days, with a daily wholesale acquisition cost of $250, the cost-offset model estimated an LOS reduction among SIADH hospitalizations of 1.11 days. The total cost offset, including tolvaptan drug cost, was estimated to be $694 per admission. The cost-neutral break-even duration of tolvaptan therapy is 6.78 days. Univariate and multivariate sensitivity analyses demonstrated consistent cost reduction associated with tolvaptan usage. Ten thousand cycles of Monte Carlo simulation showed the 95% CI for cost offset to be $73 to $1405. CONCLUSION: Based on the SALT-1 and SALT-2 trials, tolvaptan usage is associated with a shorter hospital LOS than placebo among patients with the SIADH. Including the drug cost for 4 days of inpatient tolvaptan therapy, tolvaptan is associated with an estimated mean hospital cost reduction of $694 per admission in the United States.

Vaptans are not the mainstay of treatment in hyponatremia: perhaps not yet.

Two vasopressin antagonists ('vaptans') are now in the market for the treatment of euvolemic (Europe) or euvolemic and hypervolemic (United States) hyponatremia: conivaptan for intravenous use and tolvaptan for oral application. Although their specificity and effectiveness are considered established, their indications are not. At present, we do not know which symptoms of hyponatremia and which degree of hyponatremia should serve as indications for vaptans. Other areas of uncertainty relate to the following unanswered questions: do vaptans shorten the duration of hospitalization? Is it justifiable to use them to prevent relapse of hyponatremia in (chronic) SIAD(H)? (In this text we use the abbreviation SIAD(H) instead of the recently proposed abbreviation SIAD to emphasize that vaptans will work only in the presence of ADH ('SIADH') but not in the syndrome of nephrogenic antidiuresis.) Do they decrease the high mortality associated with hyponatremia? How do we justify the cost of chronic vaptan therapy? The optimal vaptan regimen (dose, timing of controls) to treat SIAD(H) is currently not established, as is the procedure to be recommended in a too rapid correction rate of (chronic) hyponatremia. Until these requirements shall be met by additional studies, we are hesitant to consider vaptans a treatment of choice for the appropriate hyponatremias.

Venlafaxine hyponatraemia: incidence, mechanism and management.

OBJECTIVE: This prospective study was performed on patients aged >65 years commencing therapy with venlafaxine, in order to determine the incidence of hyponatraemia induced by the drug, to investigate the underlying pathophysiological mechanisms, and to evaluate a simple approach to management of this condition. METHOD: All patients aged >65 years seen by one author (MR) from all referral sources were entered into the study. Baseline biochemical tests were ordered, and if hyponatraemia developed (plasma Na <130 mmol L(-1)) additional tests were performed to ascertain the mechanism, while the patient continued on venlafaxine and fluid restriction was instituted. RESULTS: A total of 58 patients were seen, of whom 10 developed hyponatraemia, giving an incidence of 17.2%. Of these 10 patients, five were excluded from prolonged observation because of either severe medical illness, side-effects from the antidepressant or being lost to follow up. When hyponatraemia developed, it invariably did so within a few days of starting venlafaxine, and was associated with non-suppression of antidiuretic hormone in the face of a low serum osmolality. Fluid restriction (800 mL day(-1)) was effective in raising the plasma sodium to the normal range within 2 weeks, after which the fluid restriction could be relaxed without relapse occurring. These patients remained well for the follow-up period of up to 6 months. CONCLUSIONS: Patients >65 years of age should have their electrolytes measured 3-5 days after starting venlafaxine therapy. If hyponatraemia develops, it can be managed with modest fluid restriction without discontinuing drug treatment, subject to close continued clinical observation and biochemical monitoring.

Severe hyponatraemia in medical in-patients: aetiology, assessment and outcome.

BACKGROUND: Hyponatraemia is the most commonly identified electrolyte abnormality. Published data on severe hyponatraemia in general medical in-patients is lacking. AIM: To determine the aetiology, adequacy of assessment, and outcome of severe hyponatraemia in general medical in-patients. DESIGN: Retrospective case-note review. METHODS: All general medical in-patients (n = 108) with serum sodium < or =125 mmol/l were identified from the clinical chemistry database, over a six-month period. A full review of notes and computer records was undertaken at the index date and a pre-determined follow-up date. RESULTS: Follow-up data were available in 105 patients. There was a wide range of aetiologies: diuretic therapy (loop and thiazide), congestive cardiac failure and liver disease were the most common, and 75.3% of patients had multiple causes. None of the 48% of patients whose history suggested a possible diagnosis of the syndrome of inappropriate anti-diuretic hormone (SIADH) met the generally accepted diagnostic criteria. Overall mortality was 20% during the index admission and 44.6% at follow-up, vs. 7.1% and 22%, respectively, for other patients admitted to the same directorate over the same time period (p < 0.001). Mortality was linked to aetiology, but not to reduced absolute serum sodium concentration at admission. DISCUSSION: Severe hyponatraemia in general medical patients is associated with a complex, multifactoral aetiology and a very poor prognosis. Outlook is governed principally by aetiology, and not by serum sodium level. Assessment of patients with hyponatraemia requires a practical clinical algorithm for diagnosing SIADH.

Assessment of neuroendocrine dysfunction following traumatic brain injury.

Posttraumatic neuroendocrine pathology may be a clinically significant complication following traumatic brain injury (TBI). Metabolic abnormalities are described after TBI in two cases. A 21 year old male injured in a motor vehicle accident admitted in a minimally responsive condition presented with fluctuating high sodium levels, undetectable serum testosterone, and depressed cortisol and thyroid function. Imaging revealed near complete avulsion of the pituitary stalk leading to panhypopituitarism. A 38 year old male admitted for occipital skull fractures and brain contusions presented with hyponatremia and low serum testosterone. Both patients required hormonal replacement and correction of electrolyte abnormalities. A screening protocol adapted for selected patients at risk for endocrine problems is described. While neuroendocrine screening is not advocated in all TBI patients, physicians should be aware of the importance of neuroendocrine dysfunction following TBI.

Syndrome of inappropriate antidiuretic hormone: assessment and nursing implications.

Syndrome of inappropriate antidiuretic hormone (SIADH) is a condition characterized by serum hypoosmolality and hyponatremia, resulting from the aberrant or sustained secretion of antidiuretic hormone (ADH). Its most frequent cause is malignancy, of which small cell or oat cell bronchogenic carcinoma is most common. Because it mimics the clinical manifestations of various disorders, SIADH often is difficult to diagnose. However, with early detection and prompt management, it can be reversed. The oncology nurse frequently is in a position to assist in the early recognition of this condition. The ability to maintain a high index of suspicion for patients at risk is critical to prompt recognition. Familiarity with the conditions that lead to this crisis and its early signs are essential to establishing a diagnosis and administering prompt treatment.

Assessment of SIADH in psychosis with a water-loading test: case report.

A man taking haloperidol presented with psychosis, polydipsia, and the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). A water-loading test indicated that haloperidol did not cause the SIADH. In patients taking haloperidol or other neuroleptics associated with SIADH who develop psychosis, polydipsia, and complications of SIADH such as hyponatremia, water loading may be helpful in adjusting psychotropic medications so as to control psychosis while avoiding the complications of hyponatremia.