Antonio Carlos Ligocki Campos

Assessment and nutritional aspects of wound healing

Purpose of reviewThe aim of this study is to review the physiopathology and the nutritional aspects of wound healing. Recent findingsWound healing consists of a perfect and coordinated cascade of events that result in tissue reconstitution. The healing process is common to all wounds, independent of the agent that has caused it. It is divided didactically into three phases: inflammation, proliferation, and remodeling or maturation. Collagen is the most abundant protein in the human body and is also the main component of the wound matrix. It is organized in a thick and dynamic net, resulting from constant collagen deposition and reabsorption. Wound scar is the result of the interaction between collagen synthesis, degradation, and remodeling. There are several ways to evaluate wound healing: tensiometry, collagen morphometry, immunohistochemistry, and, more recently, the dosage of growth factors. Malnutrition adversely affects wound healing. On the contrary, the healing process can be stimulated by preoperative feeding and by certain nutrients such as glutamine, arginine, butyrate, and antioxidants. SummaryWound healing is a complex process that started to be fully understood only in recent years. Recent research has been directed to act in the nutrition modulation of the healing process.

Limitations and validation of bioelectrical impedance analysis in morbidly obese patients

Purpose of reviewSeveral factors limit the use of bioelectrical impedance analysis as a valid predictor of the amount of body fat in morbidly obese individuals. The purpose of this review is to examine the theory and assumptions that may limit the use of bioelectrical impedance analysis in such individuals. Recent findingsThere is currently insufficient validation of bioelectrical impedance analysis equations in obese individuals with body mass indices greater than 34 kg/m2. Several factors limit the application of bioelectrical impedance analysis in morbidly obese individuals. Obese individuals have a relatively high amount of extracellular water and total body water, which may overestimate fat-free mass and underestimate fat mass. Central body fat will generally overestimate the percentage of fat-free mass and underestimate the percentage of fat mass in overweight and obese adults with the use of prediction formulas developed in normal weight individuals. SummaryA relatively increased amount of total body water and a relative increase in extracellular water will result in an underestimation of the percentage of body fat and an overestimation of fat-free mass in the morbid obesity state. A different body build disposition (mainly in those with severe abdominal obesity) will result in an overestimation of the percentage of body fat. New equations are needed to validate bioelectrical impedance analysis in morbidly obese patients.

Nutritional support in surgical practice: Part II

On admission, a group of high-risk patients who are potential candidates for surgery can be identified, in whom prompt initiation of preoperative enteral or parenteral nutrition may reduce postoperative morbidity and mortality irrespective of the nutritional status. Among these are patients with inflammatory bowel disease, gastrointestinal fistulas, and pancreatitis. Substantial nutritional support has little or no direct effect upon the pathogenesis of the disease, but the discontinuance of oral intake may well have a beneficial effect on the basic disease process. Thus, the provision of enteral or parenteral nutrition gives the patient an optimal opportunity to marshal host defenses in support of healing. In organ system failures, e.g., acute renal failure, liver failure, and pulmonary failure, appropriate nutritional support may assist the patient in coping with the abnormal intermediary metabolism resulting from such failure until satisfactory organ system function returns. From this review, it seems reasonably clear that the initially malnourished patient is less able to successfully withstand the adverse effects of vigorous therapy and/or severe illness than is the well-nourished individual. Hence, correction of malnutrition, either before initiating therapy or concomitant with the treatment, is very likely to be beneficial.

AUTOMATED COMPUTERIZED RAT EATER METER : DESCRIPTION AND APPLICATION

A real-time Automated Computerized Rat Eater Meter was developed by modifying commercially available metabolic cages. Food access via a feeding tunnel was monitored by photocells. Food consumption was measured by an electronic scale. The signals thus generated were processed by a computer. This allowed us to continuously measure the spontaneous feeding behavior of free-feeding nondeprived Fischer rats for a sum total of 35 study days. Based on our data, we defined a meal as an episode of food consumption preceded and followed by at least 5 minutes of no feeding. Fischer rats showed periodic nychthemeral eating behavior. Food consumption, number of meals, meal sniffs, intermeal sniffs, and, consequently, eating activity were greater during the dark cycle than the light cycle. Meal duration, meal size, and thus food consumption rates remained constant throughout both cycles. Our modification of commercially available metabolic cages provides unique data for continuously monitoring rat feeding patterns over prolonged periods of time.

Use of TPN in Terminally Ill Cancer Patients

Total parenteral nutrition (TPN) is often used as an adjunct to cancer therapy. However, it is increasingly being used in terminally ill cancer patients without clearly defined reasons. To determine the validity of the use of TPN in terminally ill cancer patients, 26 patients with limited life expectancy due to end-stage cancer were given TPN by their physicians, and the validity of its use was evaluated using the criteria of 1) quality of life, and 2) ultimate outcome. Patients were divided into two groups according to the use of TPN. Group I = TPN as adjunct of medical therapy, n = 15 (eight male, seven female), mean age 32 y. Group II = TPN for in-hospital supportive care, n = 11 (two male, nine female), mean age 56 y. Nutritional status on admission, quality of life (assessed by extent of daily activities, pain, and ability to sustain oral intake), and ultimate treatment outcome were determined. Mean weight loss in patients in Group I was 8.6 kg, 11 patients out of 15 were malnourished; mean weight loss in patients in Group II was 21 kg, and all of the 11 patients belonging to this group were malnourished. Two patients of Group I improved their quality of life, while 6 declined and 7 died; in Group II, 3 improved their quality of life, 4 declined, and 4 died. We conclude that when TPN was given either as an adjunct to in-hospital aggressive therapy for cancer or for in-hospital supportive care, quality of life did not improve in the majority of patients; nor did it influence ultimate outcome. These objective data, thus, raise the question of the validity of the use of TPN in terminally ill cancer patients. However, barring the cost factor, it is recognized that subjective reasons for giving TPN to terminally ill cancer patients persist and include compassionate, ethical, religious, or emotional reasons.

The role of nutrition in hepatic encephalopathy.

Purpose of reviewProtein-calorie malnutrition may be observed in all clinical stages of liver disease. Nutritional management in these patients is imperative. It is crucial that protein intake is not restricted ad hoc. Administration of vegetable proteins for patients who cannot tolerate standard proteins and, if necessary, branched-chain amino acid-enriched formulae can be an option to these patients. This issue, however, remains controversial. Recent findingsThis study is an update on the nutritional management of hepatic encephalopathy based on several studies of the last decades, involving dietary protein intake and branched-chain amino acid supplementation. SummaryMalnutrition is a common complication of liver disease and it adversely affects patient outcome. Inadequate dietary protein intake has a very deleterious effect on hepatic encephalopathy, nutritional status, and clinical outcome in these patients and must be avoided. The administration of branched-chain amino acids stimulates hepatic protein synthesis, reduces postinjury catabolism and therefore improves nutritional status. Conflicting results in various different trials, however, exist, and this issue remains unclear.

The impact of bariatric surgery on nonalcoholic fatty liver disease.

Purpose of reviewTo analyze the effects of bariatric surgery on nonalcoholic fatty liver disease by reviewing the most important and recent studies. Recent findingsThe prevalence of obesity has increased dramatically over the last decades. Comorbidities related to obesity, such as nonalcoholic fatty liver disease are also increasing. Nonalcoholic fatty liver disease is a progressive disease with potential evolution to liver cirrhosis and hepatocellular carcinoma. Overweight patients who have nonalcoholic fatty liver disease should be considered for a weight loss program; however, long-term result with dietary interventions and drug therapy has been disappointing. Bariatric surgery is effective in promoting long-term weight loss in morbidly obese patients with control of comorbidities, especially those associated with the metabolic syndrome. On the basis of the early experience with extensive intestinal bypass, it was believed that rapid weight loss could cause liver damage. In contrast, recent prospective and retrospective observational studies and case series have demonstrated that bariatric surgery is well tolerated and is associated with nonalcoholic fatty liver disease regression in a significant number of patients. SummaryThere is good level of evidence that bariatric surgery is associated with nonalcoholic fatty liver disease regression in morbidly obese patients.

Influence of Preoperative Feeding on the Healing of Colonic Anastomoses in Malnourished Rats

BACKGROUND Malnutrition influences healing of gastrointestinal anastomoses. The authors hypothesize that colonic anastomotic healing is decreased by malnutrition and might be improved by preoperative feeding. METHODS Eighty adult male Wistar rats were divided into 4 groups: (1) control rats 1 (C1), fed regular chow ad libitum for 21 days; (2) malnourished pair-fed rats (M), fed 50% of the food ingested by the control rats for 21 days; (3) preoperative nutrition rats (PRE), fed 50% of the average of the controls for 21 days and then fed preoperative nutrition with regular chow ad libitum for 1 week before the operation; and (4) control rats 2 (C2), fed regular chow ad libitum for 28 days. On days 21 (C1 and M) and 28 (PRE and C2), rats underwent 2 colonic transections and, subsequently, 2 end-to-end anastomoses. Rats were killed on postoperative day 5. The anastomoses were resected for tensile strength and histological analysis. RESULTS PRE rats showed increased maximal tensile strength vs the M group (0.09+/-0.01 vs 0.15+/-0.01; P<.05) and similar values of maximal tensile strength as the controls (0.15+/-0.01 vs 0.15+/-0.02; P=.91). Collagen type I was higher in controls vs the PRE group (6.13+/-0.39 vs 4.90+/-1.53; P<.05); nevertheless, the PRE group showed higher collagen type I than M rats (4.90+/-0.36 vs 3.83+/-0.35; P<.05). CONCLUSIONS Preoperative feeding for 7 days increases the maximal tensile strength, as well as the percentage area of mature collagen, approaching similar values as the control group.

Nutrition support in Brazil: past, present, and future perspectives.

The history of nutrition support in Brazil is parallel to its development in the world. Inspired by the publications of the surgical group headed by Professor Rhoads at the University of Pennsylvania, a group of Brazilian physicians pioneered the beginning of parenteral nutrition (PN) therapy. The Brazilian Society of Parenteral and Enteral Nutrition (SBNPE) was officially founded in 1975. Soon, scientific contributions started to appear, reflected by articles in the Journal of Parenteral and Enteral Nutrition and other journals and by books. In many states of Brazil, nutrition support services were created to carry out scientific and educational activities. The relationship with the American Society of Parenteral and Enteral Nutrition was fundamental in the development of clinical nutrition in Brazil because of the strong scientific exchange between the United States and Brazil. However, after the stimulating initial launching, momentum slowed because of the lack of medical awareness and inadequate reimbursement. In Brazil, the federal government is responsible for the majority of health care, but enteral nutrition was not reimbursed. In response to this situation, a study in 4000 hospitalized patients was undertaken in Brazil. It was reported that nearly half of them presented with malnutrition, and > 12% had severe malnutrition. These alarming results were decisive in persuading the Brazilian government to begin reimbursement for enteral nutrition. Today, Brazilian hospitals that assist public health system patients receive reimbursement for enteral nutrition. However, it is required to have an officially registered nutrition support team and a certified and approved facility for enteral feeding preparation. Considering that low nutrition prescription in Brazil could be the result of lack of nutrition education (not required in most medical schools), the SBNPE participated in the creation of 2 very effective, practical, and dynamic courses for the basic teaching of clinical nutrition. These courses were created by the Latin American Federation of Parenteral and Enteral Nutrition: the TNT (Total Nutrition Therapy) Course and the CINC Course (Interdisciplinary Course in Clinical Nutrition). These 2 courses are available to members of all Latin American countries and are regularly offered by the SBNPE to its members all over Brazil. Altogether, > 4000 physicians, dietitians, nurses, and pharmacists have been introduced to the basic principles and practice of clinical nutrition. It is clear that the outstanding ideas of Professors Rhoads, Dudrick, and Wilmore and other collaborators from this group in the field of clinical nutrition have grown and flourished in Brazil.

Dynamics of oral intake resumption after general anesthesia and operation in rats

The influence of general anesthesia and operation on dynamics of postoperative food intake resumption was investigated in eight rats. A laparotomy was performed on each rat under anesthesia induced by intraperitoneally injected chloral hydrate. Spontaneous food intake and feeding indexes were continuously measured using an Automated Computerized Rat Eater Meter (ACREM) before and after operation. Although spontaneous food intake and all feeding indexes were depressed immediately following anesthesia and operation, each feeding index was depressed to a greater degree during the dark vs. the light cycle. Initially, rats fully capable of eating ate fewer, smaller, and shorter meals. The return to normal of each feeding index differed temporally. Thus, although meal number normalized by the third postoperative day, meal size by the sixth postoperative day, and meal duration by the fourth postoperative day, normalization of meal number during the light cycle occurred sooner than during the dark cycle, while the converse occurred with meal size and meal duration.