Reliable Quantification of the Potential for Equations Based on Spot Urine Samples to Estimate Population Salt Intake: Protocol for a Systematic Review and Meta-Analysis.

BACKGROUND: Methods based on spot urine samples (a single sample at one time-point) have been identified as a possible alternative approach to 24-hour urine samples for determining mean population salt intake. OBJECTIVE: The aim of this study is to identify a reliable method for estimating mean population salt intake from spot urine samples. This will be done by comparing the performance of existing equations against one other and against estimates derived from 24-hour urine samples. The effects of factors such as ethnicity, sex, age, body mass index, antihypertensive drug use, health status, and timing of spot urine collection will be explored. The capacity of spot urine samples to measure change in salt intake over time will also be determined. Finally, we aim to develop a novel equation (or equations) that performs better than existing equations to estimate mean population salt intake. METHODS: A systematic review and meta-analysis of individual participant data will be conducted. A search has been conducted to identify human studies that report salt (or sodium) excretion based upon 24-hour urine samples and spot urine samples. There were no restrictions on language, study sample size, or characteristics of the study population. MEDLINE via OvidSP (1946-present), Premedline via OvidSP, EMBASE, Global Health via OvidSP (1910-present), and the Cochrane Library were searched, and two reviewers identified eligible studies. The authors of these studies will be invited to contribute data according to a standard format. Individual participant records will be compiled and a series of analyses will be completed to: (1) compare existing equations for estimating 24-hour salt intake from spot urine samples with 24-hour urine samples, and assess the degree of bias according to key demographic and clinical characteristics; (2) assess the reliability of using spot urine samples to measure population changes in salt intake overtime; and (3) develop a novel equation that performs better than existing equations to estimate mean population salt intake. RESULTS: The search strategy identified 538 records; 100 records were obtained for review in full text and 73 have been confirmed as eligible. In addition, 68 abstracts were identified, some of which may contain data eligible for inclusion. Individual participant data will be requested from the authors of eligible studies. CONCLUSIONS: Many equations for estimating salt intake from spot urine samples have been developed and validated, although most have been studied in very specific settings. This meta-analysis of individual participant data will enable a much broader understanding of the capacity for spot urine samples to estimate population salt intake.

Hepatotoxic effects of therapies for tuberculosis.

Hepatotoxic effects attributable to antituberculosis therapy are considered unique among drug-related liver problems because almost all first-line antituberculosis medications have such adverse effects, which vary in severity according to the drug and the regimen. In addition, all regimens for the treatment of active tuberculosis include a combination of medications that must typically be administered for at least 6 months to ensure complete cure of the disease and to minimize the development of drug-resistant bacterial strains. Hepatotoxic effects are a serious problem in patients who are undergoing treatment for tuberculosis, not only because of the morbidity and mortality they directly cause, but also because the liver symptoms can necessitate interruption of therapy or affect a patient's adherence to it, which can limit the efficacy of the antitubercular regimen.

Fully covered Alimaxx esophageal metal stents in the endoscopic treatment of benign esophageal diseases.

BACKGROUND: Expandable esophageal stents are widely used for the palliation of dysphagia in patients with esophageal cancer and are also beginning to be used in patients with benign esophageal diseases such as refractory strictures and fistulas. There is concern regarding the increased risk of migration of the fully covered Alimaxx metal esophageal stent and experience with this stent in benign esophageal pathology has been reported in only a small series of patients. AIMS: To evaluate the technical success in placement and removal, efficacy and complications of the Alimaxx esophageal stent for benign esophageal diseases. METHODS: Our endoscopy database was retrospectively reviewed from 1/2003 to 2/2009 to identify patients with Alimaxx esophageal stent placement for benign diseases. Chart review was performed for age, gender, indication, site of the lesion, success of placement, outcome, and incidence of complications. RESULTS: Twenty-eight stents were successfully placed in 14 patients with benign esophageal diseases (mean: two stents/patient; range 1-7). Indications included esophageal fistula in seven (50%) and benign strictures in 7/14 (50%). Dysphagia improved in all patients while the fistula resolved in 6/7 (85.8%) patients. Complications related to stents included pain (2/28, 7%), stent related gastric ulcer (1/28, 4%), nausea and vomiting (3/21, 11%) and stent migration (11/28, 39%). All migrated stents were successfully endoscopically retrieved. CONCLUSIONS: The fully covered and removable Alimaxx stent is effective in the endoscopic management of benign esophageal strictures or fistulas, despite its relatively high rate of migration. Stent migration was successfully managed endoscopically without complications.

Spot urinary sodium for assessing dietary sodium restriction in cirrhotic ascites.

AIM: To evaluate the accuracy of spot urinary Na/K and Na/creatinine (Cr) ratios as an alternative to 24-h urinary sodium in monitoring dietary compliance in patients with liver cirrhosis and ascites treated with diuretics. METHODS: The study was carried on 40 patients with liver cirrhosis and ascites treated with diuretic therapy. Patients were divided into two groups according to 24-h urinary sodium. We measured spot urine Na/K ratio, Na/Cr ratio and 24-h urinary sodium. Student's t test was used to compare the interval variables and chi(2) test to compare the nominal variables between the two groups. Receiver operator characteristic curve was used to identify the best cutoff point for Na/K and Na/Cr ratio. RESULTS: The best cutoff point for Na/K ratio was 2.5 (P < 0.001) and area under the curve (AUC) was 0.9, and for Na/Cr ratio, the best cutoff point was 35 (P < 0.001) and AUC was 0.885. Na/K ratio showed higher sensitivity and accuracy compared to Na/Cr ratio (87.5% and 87% for Na/K ratio; 81% and 85% for Na/Cr ratio, respectively). CONCLUSION: Spot urine Na/K ratio has adequate accuracy for assessment of dietary sodium restriction compared with 24-h urinary sodium in patients with liver cirrhosis and ascites.

Evaluation and management of patients with refractory ascites.

Some patients with ascites due to liver cirrhosis become no longer responsive to diuretics. Once other causes of ascites such as portal vein thrombosis, malignancy or infection and non-compliance with medications and low sodium diet have been excluded, the diagnosis of refractory ascites can be made based on strict criteria. Patients with refractory ascites have very poor prognosis and therefore referral for consideration for liver transplantation should be initiated. Search for reversible components of the underlying liver pathology should be undertaken and targeted therapy, when available, should be considered. Currently, serial large volume paracentesis (LVP) and transjugular intrahepatic portasystemic stent-shunt (TIPS) are the two mainstay treatment options for refractory ascites. Other treatment options are available but not widely used either because they carry high morbidity and mortality (most surgical options) rates, or are new interventions that have shown promise but still need further evaluation. In this comprehensive review, we describe the evaluation and management of patients with refractory ascites from the prospective of the practicing physician.