Nutrition in Clinical Practice

Evidence-based practice merges the best and most relevant clinical research data with clinician experience, pathophysiology of disease state, and the specifics of individual patient care. Currently, there is a significant gap between the best research evidence in healthcare and application of this evidence to clinician practices. Consistent with this finding, nutrition support is not always applied effectively or consistently, despite available scientific evidence that could be used to enhance a given treatment protocol. Cited obstacles that prevent the incorporation of research evidence into daily practice include lack of time, inadequate research skills, and information overload. Identification and application of the most valid primary research and evidence summaries (clinical guides to practice and meta-analyses) should, however, be an integral part of appropriate nutrition care. Consequently, it is important that clinicians develop and improve upon the basic skills required to allow efficient and accurate searches and evaluations of the literature. This review describes the basic and practical components of evidence-based medicine and provides tools to determine whether current nutrition practices are based upon an analysis of valid clinical evidence or anecdotal nutrition traditions and myths.

One way in which we learn new information is to read the medical literature. Whether or not we do primary research, it is important to be able to read literature in a critical fashion. A seemingly simple concept in reading is to interpret p values. For most of us, if we find a p value that is <.05, we take the conclusion to heart and quote it at every opportunity. If the p value is >.05, we discard the paper and look elsewhere for useful information. Unfortunately, this is too simplistic an approach. The real utility of p values is to consider them within the context of the experiment being performed. Defects in study design can make an interpretation of a p value useless. One has to be wary of type I (seeing a “statistically significant” difference just because of chance) and type II (failing to see a difference that really exists) errors. Examples of the former are publication bias and the performance of multiple analyses; the latter refers to a trial that is too small to demonstrate the difference. Finding significant differences in surrogate or intermediate endpoints may not help us. We need to know if those endpoints reflect the behavior of clinical endpoints. Selectively citing significant differences and disregarding studies that do not find them is inappropriate. Small differences, even if they are statistically significant, may require too much resource expenditure to be clinically useful. This article explores these problems in depth and attempts to put p values in the context of studies.

Surrogate nutrition markers are used to assess adequacy of nourishment and to define malnutrition despite evidence that fails to link nourishment, surrogate markers, and outcomes. Markers such as serum levels of albumin, prealbumin, transferrin, and IGF-1 and delayed hypersensitivity and total lymphocyte count may be valid to help stratify risk. However, it is not appropriate to consider these as markers of adequacy of nourishment in the sick patient.

Albumin is the predominant product of hepatic protein synthesis and one of the more abundant plasma proteins. Among its multiple physiologic roles, it plays an essential part in the generation of colloid-oncotic pressure. In the United States, the indications for which albumin therapy are considered include hypovolemia or shock, burns, hypoalbuminemia, surgery or trauma, cardiopulmonary bypass, acute respiratory distress syndrome, hemodialysis, and sequestration of protein-rich fluids. The use of this relatively expensive therapy accounts for up to 30% of the total pharmacy budget in certain hospitals. The use of albumin therapy in different clinical situations and its influence in morbidity and mortality have been reviewed in multiple randomized controlled trials and meta-analyses. Despite frequent reviews, the use of albumin remains controversial in several clinical situations. At the same time, these valuable reviews seem to have documented the advantages of albumin therapy in the management of ascites and clarified the use of albumin in volume resuscitation. More studies have been recommended to investigate the use of albumin in different doses and its role in hypoalbuminemia. This article will provide an overview of albumin metabolism, use of albumin for volume expansion, the potential therapeutic role of albumin in liver disease, and the role of albumin therapy in nutrition.

The concept of nonprotein calories has been used in a variety of ways by nutrition support clinicians. Nonprotein calories may refer to the combined energy from lipid and carbohydrate but are also used to describe the balance between energy and protein in the form of the nonprotein calorie-to-nitrogen ratio. Nonprotein calories have been used as the basis for calculating nutrient needs, but this practice is no longer recommended as it may result in overfeeding. The purpose of this paper is to examine the nonprotein calorie concept using a clinical scenario and review of the literature.

Significant weight loss is a common complication of a major burn injury. Before the modern era of early enteral nutrition support, such a complication contributed significantly to impaired wound healing, raised risk of infectious morbidity, and ultimately increased mortality. Nutrition management of the burn patient is designed to promote wound healing while minimizing loss of lean body mass. The burn patient characteristically demonstrates an increase in energy expenditure after the initial injury and period of resuscitation. Studies have demonstrated that early institution of enteral feeding can attenuate the stress response, abate hypermetabolism, and improve patient outcome.

Clinicians in nearly all practice areas are confronted with the challenges associated with delayed and impaired wound healing. Although nutrition plays a critical role in the healing process, controversy exists regarding the optimal nutrition regimen. This article reviews literature related to nutrition interventions that facilitate wound healing. The limitations of the research that forms the scientific basis of many nutrition recommendations are also examined. The limited availability of rigorously performed clinical studies to develop evidence-based guidelines for nutrition support in wound care emphasizes the need for further research and underscores the importance of individualizing the nutrition care plan for each patient.

Background: Proper enteral access to deliver specialized nutrition support in critically injured patients can be difficult, time consuming, and costly. We designed a protocol with interdisciplinary input to facilitate early enteral access in our trauma patients. Our primary objective was to determine if the protocol improved our ability to obtain small-bowel access in patients within 48 hours of their admission to the surgical intensive care unit (SICU). Secondary objectives were to examine the efficacy of the protocol by evaluating parenteral nutrition (PN) use, adequacy of enteral caloric delivery, and clinical outcomes including pneumonia and sepsis rates, SICU length of stay (LOS), hospital LOS, and mortality before and after its implementation. Methods: The medical records of 51 trauma patients admitted to the SICU, who met inclusion criteria, were reviewed retrospectively and divided into 2 groups. Patients in group 1 were admitted before protocol implementation (1997–1998, n = 17). Patients in group 2 were admitted after protocol implementation (1998–2000, n = 34). Results: Small-bowel access was achieved earlier in group 2 compared with group 1 [2.2 ± 2 days vs 5.4 ± 8 days, respectively (p = .04)]. PN was used less frequently in group 2 at 41.2% (14/34) as opposed to 64.7% (11/17) in group 1 (p = .05). There was a reduction in the number of days to reach caloric goal from 4.9 days in group 1 to 3.9 days in group 2 (n.s.). Clinical outcomes were similar in both groups. Conclusions: The use of a protocol was effective in the achievement of prompt small bowel access. The number of days to reach caloric goal decreased after protocol implementation, but not to a statistically significant degree. However, we were able to detect a significant reduction in the use of PN.

Previous data clearly showed profound differences in nursing practices and techniques within the state of Texas regarding the administration of medications through enteral feeding catheters (EFCs) between long-term care (LTC) facilities that predominantly serve a rural vs an urban population. This study aims to determine the incidence and characteristics of medication administration through EFCs in the LTC setting in the United States with particular emphasis on the delineation between practices in facilities that predominantly serve a rural vs an urban population. A 36-item validated survey was mailed to the Directors of Nursing of the 16,400 LTC facilities registered with the U.S. Medicare LTC facility database registry. In all, 1278 (7.8%) surveys were included in this analysis. The majority of nurses responding were RNs (93%), with extensive years of experience (19 years), working in facilities predominantly serving a rural area (58%). There were significant differences between rural and urban facilities with regard to the percent of patients receiving medications through EFCs (6.6% vs 9.0%, p < .0001), number of oral medications/day (8.3 vs 9.4, p = .0003), amount of flush before and after administering medications (64 mL vs 59 mL, p = .0127), those attending a seminar/in-service on medication administration through EFCs (45% vs 56%, p < .0001), and medication obstruction rate (6.4% vs 3.9%, p = .0227). Medication obstruction rate was significantly increased when nurses used 3 or more inappropriate techniques (8.1% vs 4.8%, p = .0171), particularly crushing enteric-coated (8.9% vs 4.6%, p = .0003) and sustained-release dosage forms (8.5% vs 4.7%, p < .0001). Medication obstruction through EFCs is significantly increased when 3 or more inappropriate techniques are utilized. Techniques, complications, and sources of information vary significantly from rural to urban facilities and various parts of the country. A universal set of guidelines to administer medications through EFCs should be adopted and widely disseminated particularly to LTC facilities in rural areas.

We investigated whether intervention with antioxidant vitamins C and E in enteral feeding influenced oxidative stress and clinical outcome in critically ill patients. Two-hundred sixteen patients expected to require at least 10 days of enteral feeding completed the study. One-hundred five patients received enteral feeding supplemented with antioxidants, and 111 control patients received an isocaloric formula. Plasma lipoperoxidation (by thiobarbituric acid reactive substances [TBARS] and prostaglandin F_2α isoprostane levels), low-density lipoprotein (LDL) oxidizability, and LDL tocopherol content were determined at baseline and at the end of the 10-day period. The clinical 28-day outcome was also assessed. Plasma TBARS and isoprostanes were 5.33 ± 1.26 nM/mL and 312 ± 68 pg/mL, respectively, before treatment and 2.42 ± 0.61 nM/mL and 198± 42 pg/mL after intervention (p < .01 for both comparisons). Antioxidants improved LDL resistance to oxidative stress by approximately 30% (the lag time before treatment was 87 ± 23 minutes and was 118 ± 20 minutes after treatment; p < .04). There was a significantly reduced 28-day mortality after antioxidant intervention (45.7% in the antioxidant group and 67.5% in the regular-feeding group; p < .05). Isoprostanes may provide a sensitive biochemical marker for dose selection in studies involving antioxidants.

Objective: To evaluate the obstetric and medical complications with hyperemesis gravidarum, comparing those who were supported with total parenteral nutrition (TPN group) and those who did not receive TPN (non–TPN group). Study Design: The medical records of women with a diagnosis of hyperemesis gravidarum (ICD-9 code 643) admitted to Crouse Hospital, Syracuse, New York, between January 1995 and December 1998 were reviewed. A total of 166 subjects were identified and 192 admissions reviewed. Information was gathered for age, gestational age, gravity and parity, marital status, length of stay, and number of admissions, and a review of electrolyte, albumin, and thyroid function was performed. An assessment of pregnancy complications and outcomes was undertaken. Results: Of the cases reviewed, 16% (27/166) were treated with PN. The 2 groups were similar regarding incidence of pregnancy-related and maternal medical complications. The groups were similar when comparing objective measures, such as serum potassium, bicarbonate, albumin, and thyroid function. The PN group had a significantly increased incidence of complications directly attributed to parenteral therapy. Among multiparous patients in both groups, 69% had a prior pregnancy that had ended in spontaneous or induced abortion. Conclusion: The PN group had a marked and significant increase in serious complications directly related to PN use. These data suggest that great care should be taken to assess the need for parenteral therapy in patients with hyperemesis gravidarum. A history of loss in the antecedent pregnancy may be a risk factor for a subsequent pregnancy complicated by hyperemesis gravidarum.