Sodium restriction in patients with cirrhotic ascites: a protocol for a systematic review

Systematic Reviews, May 2016

Background Avid renal sodium and water retention among other mechanisms produce ascites in patients with cirrhosis. The main guidelines recommend sodium intake reduction in order to counteract this complication. However, some randomized controlled trials have suggested a lack of benefit with a sodium-restricted over an unrestricted diet, and even an increase in ascites and renal complications has been reported. There are no systematic reviews addressing this question. Methods A systematic review protocol has been designed and will be reported in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P). We will search for randomized controlled trials evaluating a salt-restricted versus unrestricted regime in patients with cirrhosis and ascites in EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials. We will also try to identify literature by reviewing reference list of included studies and relevant reviews, screening main conference proceedings, and searching for unpublished and ongoing trials in the World Health Organization (WHO) International Clinical Trials Registry Platform. Two researchers will independently undertake selection of studies, data extraction, and assessment of the quality of included studies. We will estimate pooled risk ratios for dichotomous data and the mean difference or standardized mean difference for continuous outcomes. A random effect model will be used for meta-analyses. Data synthesis and other analyses will be conducted using RevMan software. Ethics and dissemination: no ethics approval is considered necessary. Results of this study will be disseminated via peer-reviewed publications and social networks Discussion Sodium restriction is a widely accepted coadjuvant therapy for ascites; however, this indication is based primarily on expert recommendations. As far as we know, this will be the first systematic review assessing the effects of a sodium-restricted diet for ascites in cirrhotic patients. Our systematic review will aim to provide a high-quality synthesis of current evidence for patients and clinicians about this question. The main limitation might result from the reduced number and quality of primary studies available. Systematic review registration: PROSPERO CRD42015022161

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Sodium restriction in patients with cirrhotic ascites: a protocol for a systematic review

Walbaum et al. Systematic Reviews Sodium restriction in patients with cirrhotic ascites: a protocol for a systematic review Benjamin Walbaum 3 4 María Laura Valda 4 Gabriel Rada 0 1 2 0 Evidence-Based Health Care Program, Faculty of Medicine, Pontificia Universidad Católica de Chile , Santiago , Chile 1 Epistemonikos Foundation , Santiago , Chile 2 Evidence-Based Health Care Program, Faculty of Medicine, Pontificia Universidad Católica de Chile , Santiago , Chile 3 Emergency Department, Faculty of Medicine, Pontificia Universidad Católica de Chile , Lira 63, Santiago , Chile 4 Department of Public Health, Faculty of Medicine, Pontificia Universidad Católica de Chile , Marcoleta 434, Santiago , Chile Background: Avid renal sodium and water retention among other mechanisms produce ascites in patients with cirrhosis. The main guidelines recommend sodium intake reduction in order to counteract this complication. However, some randomized controlled trials have suggested a lack of benefit with a sodium-restricted over an unrestricted diet, and even an increase in ascites and renal complications has been reported. There are no systematic reviews addressing this question. Methods: A systematic review protocol has been designed and will be reported in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P). We will search for randomized controlled trials evaluating a salt-restricted versus unrestricted regime in patients with cirrhosis and ascites in EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials. We will also try to identify literature by reviewing reference list of included studies and relevant reviews, screening main conference proceedings, and searching for unpublished and ongoing trials in the World Health Organization (WHO) International Clinical Trials Registry Platform. Two researchers will independently undertake selection of studies, data extraction, and assessment of the quality of included studies. We will estimate pooled risk ratios for dichotomous data and the mean difference or standardized mean difference for continuous outcomes. A random effect model will be used for meta-analyses. Data synthesis and other analyses will be conducted using RevMan software. Ethics and dissemination: no ethics approval is considered necessary. Results of this study will be disseminated via peer-reviewed publications and social networks Discussion: Sodium restriction is a widely accepted coadjuvant therapy for ascites; however, this indication is based primarily on expert recommendations. As far as we know, this will be the first systematic review assessing the effects of a sodium-restricted diet for ascites in cirrhotic patients. Our systematic review will aim to provide a high-quality synthesis of current evidence for patients and clinicians about this question. The main limitation might result from the reduced number and quality of primary studies available. Systematic review registration:: PROSPERO CRD42015022161 Background Hepatic cirrhosis represents the final stage of progressive and irreversible liver fibrosis observed in chronic hepatic disease. Liver architecture distortion determines portal hypertension. Added neurohumoral changes produce peripheral vasodilation, increased circulating volume, and sinusoidal vasoconstriction. The exact mechanism - of peripheral vasodilatation is still unclear, but apparently, it is due to an imbalance between vasoconstrictors and vasodilators released as response to increased portal vascular resistance [1]. Circulating volume is increased primarily because of avid renal sodium and water retention due to relative hypovolemia sensed by the juxtaglomerular apparatus. Sodium and water reabsorption are mediated by increased secretion of renin, angiotensin, and aldosterone; an increased secretion of antidiuretic hormone retains free water [2, 3]. Ascites occurs as a consequence of these factors, generating a wide range of problems that affect life expectancy starting with general disability, dyspnea, peritoneal infections, renal failure, and finally death [4]. Salt restriction appears as an obvious way to avoid sodium retention and water overload. It is usually posited that in order to avoid fluid retention, oral sodium intake must be significantly reduced in order to achieve a negative sodium balance. Salt restriction would further decrease fluid accumulation by lowering portal pressure through vascular volume depletion. All major guidelines in this topic recommend salt restriction in these patients. However, some authors warn that patients with cirrhotic ascites have low blood sodium levels; therefore, the use of diuretics and sodium restriction could decrease renal perfusion, resulting in further renal impairment and more ascites. Consequently, some randomized controlled studies have suggested there would be no benefit, and even harm, with a sodium-restricted over an unrestricted diet [5, 6]. There (...truncated)


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Benjamin Walbaum, María Valda, Gabriel Rada. Sodium restriction in patients with cirrhotic ascites: a protocol for a systematic review, Systematic Reviews, 2016, pp. 78, 5, DOI: 10.1186/s13643-016-0250-4