Relevância do estado de hidratação na interpretação de parâmetros nutricionais em diálise peritoneal / Relevance of hydration status on the interpretation of nutritional parameters in peritoneal dialysis

OBJETIVO: Identificar determinantes do estado de hidratação de pacientes em diálise peritoneal crônica, bem como investigar os efeitos da sobrecarga líquida sobre o estado nutricional. MÉTODOS: Foi feito estudo transversal, realizado em 2006, avaliando 27 pacientes em diálise peritoneal crônica, acompanhados no Hospital das Clínicas da Faculdade de Medicina de Botucatu (SP), quanto a parâmetros clínicos, dialíticos, laboratoriais, antropométricos e de bioimpedância elétrica. Para avaliar a influência de parâmetros sobre o estado de hidratação empregou-se modelo de regressão linear múltipla. A amostra foi estratificada quanto ao estado de hidratação pela relação entre água extracelular e água corporal total (0,47 para homens e 0,52 para mulheres), parâmetros obtidos por meio de bioimpedância elétrica. Comparações foram realizadas por análise de covariância, Mann-Whitney, Qui-quadrado ou teste exato de Fisher. Considerou-se significância estatística quando p≤0,05. RESULTADOS: Pacientes com maior volume urinário e em modalidade dialítica automatizada apresentaram melhor estado de hidratação. Pacientes com maior sobrecarga líquida, comparados àqueles com menor sobrecarga, apresentaram menor ângulo de fase (M=4,2, DP=0,9 vs M=5,7, DP=0,7º; p=0,006), menor albumina (M=3,06, DP=0,46 vs M=3,55, DP=0,52g/dL; p=0,05) e maior por cento prega cutânea tricipital (M=75,3, DP=36,9 vs M=92,1, DP=56,9 por cento; p=0,058), sem outras evidências antropométricas. CONCLUSÃO: Pode-se sugerir que os níveis reduzidos de albumina e ângulo de fase nos pacientes com maior sobrecarga líquida não estiveram relacionados a pior estado nutricional. Para o diagnóstico nutricional em vigência de sobrecarga líquida, deve-se considerar o conjunto de variáveis obtidas por diversos métodos, buscando relacioná-las e interpretá-las de maneira abrangente, possibilitando um diagnóstico nutricional fidedigno.

OBJECTIVE: This study identified determinants of the hydration status of chronic peritoneal dialysis patients and investigated the effects of fluid overload on their nutritional status. METHODS: A cross-sectional study was conducted in 2006 to evaluate 27 chronic peritoneal dialysis patients from the Dialysis Center of the Medical School Hospital of Botucatu (SP), considering clinical, dialytic, laboratory, anthropometric and bioimpedance parameters. A linear multiple regression model was used to evaluate the influence of these parameters on hydration status. The sample was stratified according to hydration status, given by the ratio between extracellular water and total body water (0.47 for males and 0.52 for females), obtained by bioelectrical impedance. Analysis of covariance, Mann-Whitney test, chi-square test, and Fisher's exact test were used for making comparisons. The significance level was set at 5 percent (p≤0.05). RESULTS: Patients with greater urine volume and receiving automatic dialysis presented better hydration status. Patients with higher fluid overload, compared with those with lower overload, presented lower phase angle (M=4.2, SD=0.9 vs. M=5.7, SD=0.7º; p=0.006), lower albumin levels (M=3.06, SD=0.46 vs. M=3.55, SD=0.52g/dL; p=0.05), and higher percentage of triceps skinfold thickness (M=75.3, SD=36.9 vs. M= 92.1, SD=56.9; p=0.058). No other anthropometric differences were observed. CONCLUSION: Low levels of albumin and phase angle in patients with higher fluid overload were not related to worse nutritional status. This result suggests that one must consider the set of variables obtained by many methods and relate and interpret them comprehensively in order to obtain a reliable nutritional diagnosis of patients with fluid overload.

Análise da composição corporal materna pela impedância bioelétrica e sua aplicação na Obstetrícia / Maternal body composition analysis by bioelectrical impedance and its Obstetrical appliance

A análise da impedância bioelétrica é o método de avaliação da composição corporal, que é rápido e fácil de ser aplicado, permitindo a determinação da massa livre de gordura, da massa celular corporal e da água corporal total, extra e intracelular. Várias técnicas são descritas na literatura, com diferentes métodos de análise da impedância. É frequentemente utilizada na prática clínica em diversas situações como: adultos e idosos saudáveis. Porém, a análise deve ser ajustada de acordo com a raça, etnia, idade, sexo e alterações de massa livre de gordura e gordura corporal. Existem poucos estudos sobre sua aplicabilidade em mulheres grávidas, apesar de ser método de fácil aplicação para avaliar a composição corporal, além de não expor a gestante a radiações. Particularidades da gestação, tais como a hemodiluição, a alteração da geometria corporal e o acúmulo de líquido na cavidade amniótica são aspectos que podem influenciar os resultados da análise. Sua aplicabilidade na obesidade e na desnutrição demanda, algumas vezes, equações ajustadas para a população alvo. A origem da análise da impedância bioelétrica é fundamentada pelas propriedades elétricas dos tecidos que são relacionados ao seu conteúdo de água e eletrólitos. Apesar de a impedância bioelétrica ser método promissor na avaliação da composição corporal materna, é necessário que estudos obtenham informações mais precisas e validadas.(AU)

The bioelectrical impedance analysis is a method to evaluate body composition, easy and fast applied, allowing the determination of the fat-free mass, body cell mass and total body water, extra and intracellular. A lot of techniques are described in the literature, with different methods of impedance analysis. It is frequently used at clinical practice in healthy elderly and adults. However, the analysis may be adjusted with race, ethnic group, age, sex, fat free mass and body fat. There are few studies about applicability in pregnancies, despite of being an easy method to evaluate body composition and do not expose the pregnant woman to radiation. Pregnancy particularities as maternal hemodilution, body geometry change, and the fluid accumulation in amniotic cavity are aspects that may influence the results. Its applicability in obesity and malnutrition demand, sometimes, equations adjusted for target population. The origin of the bioelectrical impedance analysis is supported by electrical properties of the tissues that are related to their water and electrolytes content. The bioelectrical impedance is a promissory method to evaluate maternal body composition. However, more studies are needed to establish its accuracy and validity.(AU)

Detachment of descemet's membrane following stromal hydration in phacoemulsification surgery

Descemet's membrane detachment is mostly seen as a complication at the time of corneal incision. Stromal hydration for wound closure towards the end of phacoemulsification procedure is an unusual stage of surgery for this complication to occur. We report successful apposition of detached Descemet's membrane by using intracameral sulphur hexafluoride [SF6] gas in such a case

Assessment of Hydration on the Stratum Corneum and the Influencing Factors in Neonates / 간호학회지

PURPOSE: The study was conducted to investigate the skin hydration level in various body sites and identify the influencing factors in neonates. METHODS: An exploratory comparison study was designed to measure the stratum corneum hydration, using a National DM-R2 on the forehead, abdomen, buttocks, and the back of the hands and feet of 198 neonates including 92 premature infants. RESULTS: The results showed 32.7%-36.5% of stratum corneum hydration for all sites. Premature infants revealed a higher hydration level on the peripheral sites (dorsal hand and feet) than those of the full-term infants, possibly resulting from therapeutic regimens including an incubator or radiant warmer. Infants in an incubator showed a higher hydration level than those in radiant warmers, suggesting more attention to fluid management for infants in the open environment. In addition, all stratum corneum hydration measurements except one, from the forehead, showed a positive correlation with postnatal age in full-term infants while showing no relation to any measurements in premature infants. CONCLUSION: The study demonstrated the very low skin hydration levels in hospitalized neonates, particularly in premature neonates with more susceptible skin hydration instability despite therapeutic interventions for fluid balance. More vigilant fluid management is imperative in neonates, particularly those in the open environment.

Corneal hydration intra-operatively during phacoemulsification.

PURPOSE: To evaluate incidence and risk factors for corneal hydration intra-operatively during phacoemulsification (CHIP). METHODS AND MATERIALS: This was a randomised, clinical trial, where 240 eyes of 240 patients with senile cataracts undergoing phacoemulsification were prospectively randomised to receive one of three possible types of incision architecture - single, two or three planes. Viscoelastic injection through paracentesis, before instruments were withdrawn from the main incision, was randomly done. Incision length was grouped into 1.5, 2 and 2.5 mm. CHIP was graded as nil, mild, moderate or severe: nil - no visible CHIP, mild-CHIP involving pillars of the incision, moderate - CHIP involving pillars and lateral extension, severe - extension of CHIP in front into the clear cornea. Moderate and severe categories were combined as 'significant' CHIP. Statistical analysis was done by logistic regression. RESULTS: The incidence of significant CHIP was 17.9 % (43 eyes out of 240). Five out of 80 eyes (6.25%) single plane, 8 out of 80 (10%) two plane and 30 out of 80 (37.5%) three- plane incisions developed significant CHIP (p = 0.005). Fifteen out of 120 (12.5%) with and 28 out of 120 (23.3%) without injection of viscoelastic developed significant CHIP (p = 0.044). Eighteen out of 43 (42.8%) and 25 out of 43(58.1%) with incision lengths 2 and 2.5 mm developed significant CHIP respectively (p<0.001). CONCLUSIONS: The incidence of significant CHIP was 17.9 %. Three-plane incisions, not injecting viscoelastic prior to retraction of instruments and incision length 2 mm or more are risk factors for significant CHIP.

Efecto citotóxico en colon humano de Escherichia coli enterohemorrágico aislado de terneros con diarrea sanguinolenta / Cytotoxic effect in human colon of enterohemorrhagic Escherichia coli isolated from calves with bloody diarrhea

Escherichia coli productor de toxina Shiga (STEC) es el patógeno emergente en alimentos de mayor impacto, siendo su principal reservorio el ganado bovino. STEC puede causar diarrea, colitis hemorrágica y síndrome urémico hemolítico. El presente trabajo estudió la acción citotóxica de dos cepas de STEC aisladas de heces de terneros diarreicos en colon humano in vitro. Los fragmentos se montaron como un diafragma en una cámara de Ussing y se incubaron con las cepas patógenas. El flujo neto absortivo de agua (Jw) disminuyó y la corriente de cortocircuito (Isc) aumentó significativamente (P < 0,01) con respecto al control negativo. Los tejidos presentaron erosión de la mucosa, exfoliación del epitelio, y presencia de pseudomembranas en el lumen. A nivel de la lámina propia se observaron lesiones circulatorias leves. Una moderada infiltración de neutrófilos se observó en el lumen y en las células epiteliales. Las criptas colónicas no se vieron afectadas. El grado de lesión fue similar en ambas cepas experimentales. Este es el primer estudio que demuestra que cultivos de cepas de STEC aisladas de ganado bovino producen efectos citotóxicos en colon humano in vitro.

Shiga toxin-producing E. coli (STEC) is one of the most important emergent pathogen in foods, being its main reservoir bovine cattle. STEC can cause diarrhea, hemorrhagic colitis and hemolytic-uremic syndrome. The present work have studied the cytotoxic action in human colon of cultures of two STEC strains isolated from faeces of calves with bloody diarrhea. Colonic mucosa was mounted as a diaphragm in a Ussing chamber and incubated with the cultures of pathogenic strains. Net water flow (Jw) decreased and the short-circuit current (Isc) increased significantly (p < 0,01) compared to negative control. Tissues showed an erosion of the mucose, epithelial exfoliation, and presence of pseudo-membranes in the lumen. Mild circulatory lesions were observed in the lamina propia. A moderate neutrophils infiltration was observed in the lumen and into the epithelial cells. Colonic crypts were not disrupted. Both experimental strains caused a similar lesion on colon tissues. This is the first study that shows that cultures of STEC strains isolated from bovine cattle produce cytotoxic effects in vitro in human colon.

Development of Anthropometry-Based Equations for the Estimation of the Total Body Water in Koreans

For developing race-specific anthropometry-based total body water (TBW) equations, we measured TBW using bioelectrical impedance analysis (TBW(BIA)) in 2,943 healthy Korean adults. Among them, 2,223 were used as a reference group. Two equations (TBW(K1) and TBW(K2)) were developed based on age, sex, height, and body weight. The adjusted R2 was 0.908 for TBW(K1) and 0.910 for TBW(K2). The remaining 720 subjects were used for the validation of our results. Watson (TBW(W)) and Hume-Weyers (TBW(H)) formulas were also used. In men, TBW(BIA) showed the highest correlation with TBW(H), followed by TBW(K1), TBW(K2) and TBW(W). TBW(K1) and TBW(K2) showed the lower root mean square errors (RMSE) and mean prediction errors (ME) than TBW(W) and TBW(H). On the Bland-Altman plot, the correlations between the differences and means were smaller for TBW(K2) than for TBW(K1). On the contrary, TBW(BIA) showed the highest correlation with TBW(W), followed by TBW(K2), TBW(K1), and TBW(H) in females. RMSE was smallest in TBW(W), followed by TBW(K2), TBW(K1) and TBW(H). ME was closest to zero for TBW(K2), followed by TBW(K1), TBW(W) and TBW(H). The correlation coefficients between the means and differences were highest in TBW(W), and lowest in TBW(K2). In conclusion, TBW(K2) provides better accuracy with a smaller bias than the TBW(W) or TBW(H) in males. TBW(K2) shows a similar accuracy, but with a smaller bias than TBW(W) in females.

Normal Values of Total Body Water in Healthy Korean Adults: Comparison with Data from Western Populations

To find reference total body water (TBW) values in healthy Korean adults, we performed single frequency bioelectrical impedance analysis on 2942 healthy adults and compared these data with those of normal western adults. Males were found to have greater TBW than females. Conversely, females were found to have greater percent fat (pFat) than males. In both sexes, body weight (BW) and TBW were significantly lower in age groups of or= 60 years than in the 40 - 49 years age group. pFats were significantly higher in age groups of 50 - 59 and >or= 60 years than in the 40 - 49 years age group. pFats were similar among age groups of < 30, 30 - 39, and 40 - 49 in both sexes. In all age groups, pFats were significantly higher in females than in males. TBW was significantly correlated with BW, height (HT), fat mass, and body mass index (BMI) in both sexes. There was a significant correlation between TBW and age in males(r=-0.15, p=0.00), but not in females (r=-0.02, p=0.45). On linear regression analysis, TBW values were independently associated with BW, HT and age in males and were independently associated with BW and BMI in females. In all age groups, Korean males and females had lower mean TBW than in Western populations. However, this difference was greater in males than in females. In summary, we represented the contemporary normal TBW data in healthy Korean adults. At present, there are no national reference data relating TBW in Korea. We hope the results of this study will be useful as the baseline data for the evaluation of hydration and nutritional status in healthy and ill adults, including end-stage renal disease (ESRD).

Transepidermal water loss during conventional phototherapy in nonhemolytic hyperbilirubinemia term infants.

The evaporation rate from the skin was measured in 40 healthy term infants and 40 non-hemolytic jaundice term infants who required phototherapy. All infants were born at the gestational age of 38-41 weeks. The method for measurement of evaporation rate was based on determination of the water pressure gradient close to the skin surface. Conventional phototherapy was given in open cribs. In the phototherapy group, non of the infants had received phototherapy before the start of measurement. Evaporation rate was measured at the chest, interscapular and buttock. The measurement was made before phototherapy, 30 minutes, and 6 hours after starting phototherapy. The mean evaporation rate increased from 7.2 to 7.8 and 8.4 g/m2 h, respectively (p<0.001). In the control group, the measurement was made at the consecutive time as in the phototherapy group. The mean of the evaporate rate was 7.3, 7.6 and 7.5 g/m2 h (p=0.30). We conclude that conventional phototherapy in full term infants in open cribs increases transepidermal water loss.

Total energy expenditure & physical activity level in chronically energy deficient Indian males measured by the doubly labelled water technique.

Total energy expenditure (TEE) and basal metabolic rate (BMR) in the free-living state were measured in healthy south Indians, by the doubly labelled water (DLW) method. From these measurements, estimates of physical activity level (PAL) could be calculated. A total of 18 subjects were studied in 3 groups of 6 subjects each: Group I (urban controls), Group II (urban slum, chronically undernourished) and Group III (rural). The urban slum recruits were chronically energy deficient (CED), and had a low BMI (average 17.0 kg/m2), while the rural subjects had an average BMI of 18.1 kg/m2. The TEE measured by the doubly labelled water technique was 11.2, 7.1 and 12.2 MJ/day for Groups I, II and III respectively. The TEE was significantly lower in the urban CED group as obtained by the one way ANOVA. The estimates of TEE by the DLW technique were compared with estimates made by whole body calorimetry, in the urban groups of subjects. The TEE obtained by calorimetry was 10.3 +/- 1.6 and 7.3 +/- 0.2 MJ/day in Groups I and II respectively. There were no significant differences between the TEE measured by the two methods, in both the groups. The two methods also correlated well, and the mean difference between the methods, in both groups was -0.5 +/- 1.1 MJ/day, which was about 6 per cent of the value of TEE measured by the DLW method. The calculated PAL (by using TEE measured by DLW/BMR) was 1.79, 1.54 and 1.90 for Groups I, II and III respectively. The results showed that the activity of chronically energy deficient subjects, in urban slums, was reduced, and that this may be their method of conserving energy to maintain a stable body weight. Rural males had a high activity level, even though they had a low BMI.

Changes in body fluid and energy compartments during prolonged hunger strike

Prolonged total food deprivation in non-obese adults is rare, and few studies have documented body composition changes in this setting. In a group of eight hunger strikers who refused alimentation for 43 days, water and energy compartments were estimated, aiming to assess the impact of progressive starvation. Measurements included body mass index (BMI), triceps skinfold (TSF), arm muscle circumference (AMC), and bioimpedance (BIA) determinations of water, fat, lean body mass (LBM), and total resistance. Indirect calorimetry was also performed in one occasion. The age of the group was 43.3+/-6.2 years (seven males, one female). Only water, intermittent vitamins and electrolytes were ingested, and average weight loss reached 17.9 percent. On the last two days of the fast (43rd-44th day) rapid intravenous fluid, electrolyte, and vitamin replenishment were provided before proceeding with realimentation. Body fat decreased approximately 60 percent (BIA and TSF), whereas BMI reduced only 18 percent. Initial fat was estimated by BIA as 52.2+/-5.4 percent of body weight, and even on the 43rd day it was still measured as 19.7+/-3.8 percent of weight. TSF findings were much lower and commensurate with other anthropometric results. Water was comparatively low with high total resistance, and these findings rapidly reversed upon the intravenous rapid hydration. At the end of the starvation period, BMI (21.5+/-2.6 kg/m2) and most anthropometric determinations were still acceptable, suggesting efficient energy and muscle conservation. Conclusions: 1) All compartments diminished during fasting, but body fat was by far the most affected; 2) Total water was low and total body resistance comparatively elevated, but these findings rapidly reversed upon rehydration; 3) Exaggerated fat percentage estimates from BIA tests and simultaneous increase in lean body mass estimates suggested that this method was inappropriate for assessing energy compartments in the studied population; 4) Patients were not morphologically malnourished after 43 days of fasting; however, the prognostic impact of other impairments was not considered in this analysis

Inhibitory effect of high [Mg2+]on the vasopressin-stimulated hydroosmotic permeability of the isolated perfused cortical collecting duct

High magnesium concentration inhibits the effect of arginine vasopressin (AVP) on smooth muscle contraction and platelet aggregation and also influences hepatocyte AVP receptor binding. The aim of this study was to determine the role of magnesium concentration [Mg2+] in AVP-stimulated water transport in the kidney collecting duct. The effect of low and high peritubular [Mg2+&] on the AVP-stimulated osmotic water permeability coefficient (Pf) was evaluated in the isolated perfused rabbit cortical collecting duct (CCD). Control tubules bathed and perfused with standard Ringer bicarbonate solution containing 1 mM Mg2+ presented a Pf of 223.9 + OR - 27.2 µm/s. When Mg2+ was not added to the bathing solution, an increase in the AVP-stimulated Pf to 363.1 + OR - 57.2 µm/s (P<0.05) was observed. An elevation of Mg2+ to 5 mM resulted in a decrease in Pf to 202.9 + OR - 12.6 µm/s (P<0.05). This decrease in the AVP-stimulated Pf at 5 mM Mg2+ persisted when the CCDs were returned to 1 mM Mg2+, Pf = 130.2 + or - 20.3 µm/s, and was not normalized by the addition of 8-[4-chlorophenylthio]-adenosine 3',5'-cyclic monophosphate, a cAMP analogue, to the preparation. These data indicate that magnesium may play a modulatory role in the action of AVP on CCD osmotic water permeability, as observed in other tissues

Body water distribution in newborn infants appropriate for gestational age.

Total body water (TBW), extracellular water (ECW) and intracellular water (ICW) were measured within 6 h of birth in 99 appropriate for gestational age (AGA) infants. The two groups of infants included were term (mean +/- SD gestation 272 +/- 7 days) and preterm (mean +/- SD gestation 238 +/- 11 days) infants. The mean TBW +/- SD was 777 +/- 26 ml/kg in preterm infants and 737 +/- 26 ml/kg in term infants. The corresponding ECW was 349 +/- 26 ml/kg and 331 +/- 30 ml/kg respectively. Weight was the best correlate of TBW (r = 0.98) and ECW (r = 0.92) volumes. TBW per unit of body weight showed significant decline with increasing gestation (r = -0.54) and birth weight (r = -0.51). ICW per kg showed a moderate correlation with TBW (r = 0.63), whereas ECW per kg had a low correlation (r = 0.35) with it. TBW/kg in our infants was comparable to infants from other ethnic groups. ICW/kg, however, was consistently higher and ECW/kg lower at all stages of maturation in Indian infants as compared to Caucacian and Negroid infants.

Effect of moderate & high loadings on the proteoglycans & water content of bovine knee joint articular cartilage.

Variations in proteoglycans and water content of the knee joint cartilage were found to occur when the joint was subjected to articulating motion under moderate and high loadings. It was found that at a moderate load of 150 kg there were an increase in the percentage of proteoglycans but the percentage decreased when the joint was articulated at a high loading of 300 kg. It has also been observed that the ratio of water content and the proteoglycans decreased at moderate load, whereas the ratio increased at high load. The observed changes in proteoglycans and water content in extracellular matrix with moderate and high loadings suggested that articular cartilage properties respond to mechanical stresses.

Depuración osmolar y de agua libre en los trastornos hidroelectrolíticos en pediatría: utilidad clínica / Osmolar and free water clearences in water electrolyte diseases in pediatrics: clinical use

La evaluación clínica de un lactante con un trastorno hidroelectrolítico puede resultar difícil debido a los trastornos osmolares que lo acompañan. La definición de algunos parámetros de laboratorio que puedan informar al clínico de los eventos fisiopatológicos en curso resulta por lo tanto, de inestimable valor. En este artículo se discuten los mecanismos normales involucrados en la mantención del equilibrio hidroelectrolítico, y se analiza la importancia que revisten los conceptos de depuración osmolar y de agua libre en la práctica clínica