Balbino, Vanessa

Silva, Orlando de Castro e

English

Cadernos Espinosanos (E-Journal)

Medicina (Ribeirão Preto) 2012;45(1): 1-4The functional integrity of the liver is essential for the utilization of nutrients. The liverinfluences the nutritional status by its production ofbile acids and its role in the intermediate metabolismof proteins, carbohydrates, fats and vitamins.1Both acute and chronic liver injuries frequentlyhave nutritional consequences directly proportional totheir severity which may progress to hepatic cirrho-sis.1 Hepatic cirrhosis is characterized by chronic andirreversible alteration of the liver parenchyma due tomodifications of both hepatic structure and of the func-tional capacity of the hepatocytes and of the portalcirculation.1 Together, these alterations result in a pro-gressive loss of liver shape and function, compromis-ing to a varying extent the nutritional status and bodyhomeostasis of patients affected by the disease.1Hepatic cirrhosis is multifactorial and, accord-ing to its etiology, can be classified as metabolic, viral,alcoholic, drug-induced, autoimmune, biliary, and cryp-togenic.1 One of the methods used to assess the prog-nosis of hepatic disease is the Child-Pugh (CP) classifi-cation, table 1, which considers five factors that mayaffect prognosis and survival, i.e., ascites, hepatic en-cephalopathy, bilirubin and albumin levels, and pro-thrombin time.2Unfortunately, this classification does not con-sider the nutritional status. Although albumin is con-sidered to be a marker of nutritional status, in this caseNutritional assessment of cirrhoticpatients: A new approach based onelectrical bioimpedanceAvaliação nutricional do paciente cirrótico: Uma nova abordagem atravésda bioimpedância elétricaVanessa Balbino1, Orlando de Castro e Silva21. Nutricionista graduada em Nutrição e Metabolismo pela FMRP-USP, com aprimoramento em Nutrição Hospitalar pelo HCFMRP-USP2. Professor titular do Departamento de Cirurgia e Anatomia da FMRP-USP e Editor da Revista MedicinaTable 1Child-Pugh classification2POINTS 1 2 3ENCEPHALOPATHY ABSENT 1-2 3-4Ascites Absent Mild or controlled At least moderatewith a diuretic despite diuretic therapyBilirubin < 2 2 – 3 > 3Albumiin (mg/DL) > 3.5 2.8 - 3. 5 < 2.8Prothrombin time INR < 1.7 1.70 – 2.3 > 2.3CHILD A: 5-6 points CHILD B: 7-9 points CHILD C: 10-15 pointsEDITORIAL2Medicina (Ribeirão Preto) 2012;45(1): 1-4http://www.fmrp.usp.br/revistaBalbino V, Castro e Silva O.Editorialit may be altered due to changes inherent to the he-patic disease itself and not necessarily to malnutrition.According to the score obtained, patients can be clas-sified as Child-Pugh class A (mild), B (moderate) and C(severe).2Alberino et al3 demonstrated that malnutritionis an independent predictor of survival and that theinclusion of arm muscle circumference (AMC) and tri-cipital skin fold (TSF) improves the prognostic preci-sion of the CP classification. Thus, it is probable thatnutritional status could be a useful addition to CP clas-sification in the evaluation of the prognosis of cirrhoticpatients.3 The problem is that these anthropometricmeasures depend on the training of the anthropometristand are not precise.Although the CP classification has been themodel most widely used to assess the prognosis of cir-rhotic patients, its use is limited in individuals withclosely similar laboratory markers and due to the sub-jective nature of measurements for the quantitation ofascites and encephalopathy. Thus, as an alternativefor the assessment of prognosis, the Model End-StageLiver Disease (MELD) has been used.2 This model usesthree laboratory indices: international normalized ratio(INR), bilirubin and serum creatinine and can discrimi-nate in a more effective manner between patients whoare likely to die and patients who will survive for atleast three months.4 Like the CP classification, theMELD does not incorporate measurements of nutri-tional status. The potential prognostic value of addingnutritional status to both the CP classification and theMELD is unknown.Nutritional status is considered to be a predic-tor of morbidity and mortality in patients with advancedhepatic disease. Malnutrition also has important impli-cations in liver transplantation and it has been demon-strated that patients with a worse nutritional statusbefore the transplant have increased postoperativecomplications and higher mortality rates.5In a study on 300 patients, Carvalho et al6showed that more than 55% of those with advancedhepatic disease had some degree of malnutrition, whichwas moderate to severe in 40%. In the same study,95% of Child-Pugh class C patients were malnourished,as also were 74% of class B and 46% of class A pa-tients.6 The high prevalence of malnutrition even inpatients in the early stages of the disease is a sourceof concern. Among the causes of malnutrition in thesepatients, particularly important are insufficient foodintake, malabsorption and metabolic disorders.5 Insuf-ficient food intake may be caused by a series of fac-tors. As is the case for other chronic diseases, ano-rexia makes a significant contribution to malnutrition,possibly being caused by physical symptoms of discom-fort such as nauseas, swelling, fatigue and vomiting.Patients with ascites often have early satiety resultingfrom the mechanical effects of ascitic fluids that com-press the stomach.5In addition, the loss of appetite may be relatedto the increased regulation of inflammation and of ap-petite mediators.5 Besides the hormonal influences andphysical discomfort, the lack of interest in food mayresult from food restrictions and changes in taste.5Dietary limitations such as sodium restriction forthe control of ascites, preoperative fast, and limitationof protein intake due to severe hepatic encephalopa-thy may reduce the variety of foods and many patientsdo not accept the recommended foods. Althoughchanges in taste may be commonly attributed to mi-cronutrient deficiencies, several investigators havequestioned whether they might be a consequence ofcirrhosis itself.5It is also important to consider the anorexia re-lated to alcohol. According to the American Liver Foun-dation, 10% -20% of chronic alcohol users developcirrhosis. A poor and irregular diet is common amongpatients with alcoholic cirrhosis.5Malabsorption may be caused by pancreatic in-sufficiency and cholestasis and may be related to drugsthat cause diarrhea (lactulose, antibiotics, diuretics,and cholestyramine).5 Several mechanisms can leadto the malabsorption of nutrients, fats in particular, incirrhotic patients. A complication that affects nutrientabsorption is the portosystemic shunt. With the pro-gression of cirrhosis, the nutrients bypass the liverthrough the portosystemic shunt without being proc-essed metabolically.5 In addition, many patients withcirrhosis due to alcohol abuse have chronic pancreati-tis, which contributes to malabsorption.5Another factor that leads to fat malabsorptionin patients with cirrhosis is bile deficiency, which im-pairs the formation of micelles and the absorption oflong-chain fatty acids through the usual lymphatic sys-tem. Portal absorption of these fatty acids may alsooccur in patients with cirrhosis.5Among the metabolic disorders we may men-tion hypermetabolism during complications such asinfections, hemorrhage, decompensation and ascites;Medicina (Ribeirão Preto) 2012;45(1):1-4http://www.fmrp.usp.br/revista3Balbino V, Castro e Silva O.Editorialincreased protein catabolism due to inflammation andimpaired hepatic synthesis; reduced glucose homeos-tasis due to hepatic insulin resistance caused bychanges in gluconeogenesis, low glycogen stores andimpaired glycogenolysis; increased lipolysis and lipidoxidation, and proinflammatory cytokines (TNFα,interleukins and leptin).5Malnutrition may also be related to iatrogeniccauses involved in investigative procedures, to fastingperiods, protein restriction during periods of encepha-lopathy, and to large volumes of paracentesis.5Energy expenditure is also known to contributeto the decline of nutritional status.5 While most cir-rhotic patients have a resting energy expenditure (REE)similar to predicted values, 15% to 30% of them arehypermetabolic. Hypermetabolism may be defined asan REE of 120% compared to predicted values.5The nutritional assessment of these patients isa challenge and should be performed with caution sincechanges inherent to the liver disease itself such asedemas, ascites and protein changes impair this task,preventing the use of the more traditional parametersfor nutritional assessment. The 2006 guidelines of theEuropean Society of Enteral and Parenteral Nutrition(ESPEN) recommend the use of subjective global as-sessment (SGA), anthropometric analysis and hand gripstrength test (HGS) to identify patients with cirrhosiswho are at risk for malnutrition.5 SGA is a rapid toolfor assessment used to collect information about foodintake, changes in weight and gastrointestinal symp-toms, including observations of loss of subcutaneousfat, loss of muscle mass, edema, and ascites. Thistool is commonly used to assess patients with hepaticdisease because it is simple and inespensive.5Although the traditional anthropometric meas-urements such as weight, arm circumference and tri-cipital skin fold are considered to be adequate for thedetermination of the nutritional status of cirrhotic pa-tients, this assessment should be careful.Albumin is a poor nutritional marker because itis typically reduced in patients with advanced hepaticdisease and fluctuates during periods of inflammation.5The HGS measures the strength of hand andforearm muscles. It is a simple and rapid tool for theassessment of nutritional status, although its use as asingle evaluation has not been well established.5 Themuscle strength test was compared to SGA in cirrhoticpatients and proved to be a superior predictor of clini-cal complications such as decompensated ascites,hepatic and bacterial encephalopathy, peritonitis andhepatorenal syndrome. Malnutrition starts within thecells with a disequilibrium of the electrolytes, and mus-cle function can reflect this more rapidly.5Thus, SGA, anthropometric measurements andthe HGS are more commonly used in routine nutritionalassessment. However, there is no gold standardmethod of easy application and low cost, without sub-jective data and not influenced by the professional whoperforms it.5The analysis of bioelectrical impedance (BIA) isa sensitive, reproducible, safe and inexpensive methodthat can be used to determine nutritional status. Thismethod is based on the property of the body of con-ducting an electric current, which has been known forhundreds of years. Tissues with a greater amount ofwater, due to the dissolution in electrolytes, are themajor pathways of electric conduction, while body fatand bones are considered to be worse conductors.7 Alow alternating electrical current is conducted througha pair of electrodes while another pair, in which im-pedance is measured, measures the fall in tension.BIA measures parameters such as resistance (R) andcapacitance (Xc), recording the fall in tension in theapplied current. This change in tension is quantitatedgeometrically as the angular transformation of the pro-portion of capacitance to resistance, or phase angle(PA). The PA reflects the relative contribution of fluid(resistance) and cell membranes (capacitance) of thehuman body.7Lean and fat body mass can be calculated. Leanmass is proportional to the amount of water, consider-ing a 53.2% water constant in lean mass. When leanmass is subtracted from weight, fat mass is obtained.Since cirrhotic patients usually have fluid retention andascites, i.e., they do not have a normal distribution ofbody water, this calculation of lean mass and fat massis not indicated.However, the PA has been used as a prognosticmarker in various clinical conditions in which the integ-rity of the cell membrane is compromised and changesin fluid balance are observed, such as the malnutritionof advanced neoplastic diseases.7 This measure hasseveral advantages such as being independent of re-gression equations and the fact that it can be calcu-lated even in situations in which it is not possible toestimate body composition.7 In a recent study,Fernandes et al7 found that the PA is the only param-eter for nutritional assessment that is correlated with4Medicina (Ribeirão Preto) 2012;45(1): 1-4http://www.fmrp.usp.br/revistaBalbino V, Castro e Silva O.Editorialthe severity of hepatic disease assessed by the CP clas-sification and emphasized the importance of establish-ing a cut-off point as a parameter for the classificationof malnutrition in the population of cirrhotic patients.7Thus, the interest in comparing the PA to othermethods used for the nutritional assessment of cir-rhotic patients is clearly justified, in order to obtaindata about its performance as an indicator of the nu-tritional status of these patients. In addition, a precise,low-cost and reproducible nutritional parameter couldbe included in the Child-Pugh and MELD equations,contributing to a better prognosis for patients.REFERENCES1- Friedman S, Schiano T. Cirrhosis and its sequelae. In: GoldmanL, Ausiello D, eds. Cecil Textbook of Medicine. 22nd ed. Phila-delphia: Saunders, 936-44, 2004.2- A Basile-Filho, EA Nicolini, M Auxiliadora-Martins, GC Alkmim-Teixeira, EZ Martinez, OA Martins-Filho, Castro e Silva O. Com-parison of acute physiology and chronic health evaluation IIdeath risk, Child-Pugh, Charlson, and model for end-stageliver disease indexes to predict early mortality after liver trans-plantation. Transplant Proc. 2011; 43:1660-4.3- Alberino F, Gatta A, Amodio P, Merkel C, Di Pascoli L, Boffo G,Caregaro L. Nutrition and survival in patients with liver cirrhosis.Nutrition. 2001;17:445-50.4- Basile-Filho A, Nicolini EA, Auxiliadora-Martins M, Castro eSilva Jr. O. The use of perioperative serial blood lactate lev-els, the APACHE II and the postoperative MELD as predictorsof early mortality after liver trasplantation. Acta cir bras. 2011;26: 535-40.5- Cheung k, Lee SS, Raman M. Prevalence and mechanisms ofmalnutrition in patients with advanced liver disease, and nu-trition management strategies. Clin gastroenterol hepatol. 2012;10: 117-25.6- Carvalho l, Parise ER. Evaluation of nutritional status ofnonhospitalized patients with liver cirrhosis. Arq gastroenterol.2006; 43: 269-74.7- Fernandes SA, Bassani L, Nunes FF, Aydos MED, Alves AV, MarroniCA. Nutritional assessment in patients with cirrhosis. Arqgastroenterol. 2012; 49:19-27.

Nutritional assessment of cirrhotic patients: A new approach based on electrical bioimpedance

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Avaliação nutricional do paciente cirrótico: Uma nova abordagem através da bioimpedância elétrica

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