الفهرس 
Diabetes MellitusOnly 14 pages are availabe for public view
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Abstract
Nutritional support has become a routine part of the care of the critically ill patient. It is an adjunctive therapy, the main goal of which is to attenuate the development of malnutrition. The effectiveness of nutritional support is often stymied by an underlying hostile metabolic milieu. The design of a nutritional support regimen must, therefore, take into consideration this disordered metabolic situation (Martindale et al., 2009)
The field of nutrition support is based on two closely
related concepts first is that thenutrient depletion is associated
with increased morbidity and mortality, and second is this
association is causative, the prevention or correction of nutrient
depletion can minimize or eliminate malnutrition-related
morbidity and mortality. This construct leads to three potential
goals of nutrition assessment (Dietitians Association of
Australia., 2011)
Physical examination of the patient is important during the
initial assessment, particularly in critical illness when other
indicators are affected by the patient’s acute condition (Dietitians
Association of Australia DAA., 2011).
Day-to-day management of an enterally fed patient requires attention to practical aspects of tube feeding. (See complications section for management of feeding problems.) (Dietitians Association of Australia DAA., 2011)..
There has been increased emphasis on using the enteral route for nutritional support occasioned by the desire to maintain gut integrity and so lessen the translocation of bacteria from the gut. Lack of enteral intake, such as occurs among postoperative and critically ill patients receiving only parenteral nutrition, is associated with small intestinal villus atrophy, decreased villus cell count and reduced mucosal thickness, but not with changes in crypt cell count. Intestinal permeability, measured using the urinary lactulose :mannitol ratio, is increased. Also, crypt length is increased and mucosal surface patterns change from finger-like to leaf-like microvilli (American Society of Parenteral and Enteral Nutrition (ASPEN) Giudlines2009).
These changes were reversed with enteral feeding. Similar changes, along with activation of the lamina propria mononuclear cells and enterocytes, were seen during nutritional depletion. Interestingly, there was no evidence of mucosal atrophy among patients who had received 10 days of preoperative parenteral nutrition. It is thought that these anatomic changes in and of themselves do not lead to bacterial translocation, but that further insult is needed. One such insult is ischaemia– reperfusion injury to
the small intestines after resuscitation from an episode of shock,
which may also itself change gut integrity. Furthermore, in the
stressed patient there is the possibility that the constantly
proliferating gut tissues (epithelial and lymphoid cells) may have an
inadequate supply of nutrients, further compromising gut integrity
(Martindale et al., 2009).
These changes in gut integrity have led many to consider
whether after a systemic insult intestinal translocation of bacteria
occurs in critically ill humans. This concern is based on studies of
animal models that describe the translocation of gut organisms
across intestinal mucosa with enhanced permeability. This
bacterial translocation leads to local activation of the gut’s
immune inflammatory system (Peyer’s patches and hepatic
Kuppfer cells). The released cytokines and other mediators then
exacerbate the already existing systemic inflammatory response
syndrome leading to multiple organ failure (Rice et al., 2012).
This ‘gut hypothesis of multiple organ failure’ has led to the recommendation that enteral nutrition be started as soon as possible after surgery or in nonsurgical patients after admission to the intensive care unit. It is hoped that enteral nutrition will preserve splanchnic flow and prevent mucosal breakdown. Further impetus to begin enteral nutrition early has been lower stress hormone concentrations, lower infection rates, shorter hospital
stays and better survivals in some, but not all studies in which nutrition was started within 4–24 h, and not more than 24 h after admission (Rice et al., 2012).
Many different enteral formulas are available, through several different companies. The dietitian selects an appropriate formula based on an individual nutrition assessment of the patient.The choice of feed to be given via ETF is influenced by a patient’s nutritional requirements, any abnormality of gastrointestinal absorption, motility, or diarrheal loss, and the presence of other system abnormality, such as renal or liver failure. Most commercial feeds contain 1.0 kcal/ml, with higher energy versions containing 1.5 kcal/ml. They are generally available in fibre free and fibre enriched forms. They are nutritionally complete but expert dietetic advice should be sought. Producing feeds locally by using a liquidiser is not recommended due to the high infective risks and potentially poor nutritional quality in terms of micronutrient provision (McAtear et al .,1999).
There are many specialty formulae available in addition to the ones listed above. For example, formulae specifically designed for people with diabetes or respiratory disorders; formulae for wound healing; low sodium formulae; low energy formulae etc. In many cases the evidence for their benefit is limited and should be reviewed critically in order to assess the
formula’s appropriateness for an individual patient.”
• Parenteral nutrition (PN) should not be instituted when adequate oral or enteral nutrition is possible.
• Critically ill patients without symptoms of malnutrition, who probably cannot be adequately nourished enterally for a period of <5 days, do not require full PN but should be given at least a basal supply of glucose (Ziegler ., 2009).
Patients who can be nourished orally or enterally should certainly be nourished this way. The negative consequences of PN observed in earlier studies probably occurred as a result of unphysiologic composition and infrequent monitoring of PN (too high energy used, badly monitored BS (blood sugar) levels) rather than because of the parenteral substrate administration. Recent studies have shown that, compared with enteral nutrition, there is not necessarily a connection between PN and a higher rate of complications or a worse prognosis (Sacks et al., 2009).
Patients receiving ETF should be closely monitored, particularly early after instigation. Monitoring allows quantification of losses to enable daily estimation of replacement requirements, maintenance of metabolic balance, detection of toxicity/deficiency states, and early detection of complications. As well as recording the volume and type of feed administered, early
monitoring requires blood glucose to be checked at 4–6 hour intervals and plasma sodium, potassium, magnesium, and phosphate to be checked daily. This is especially true in patients who have had a prolonged period with little or no nutrient intake.
Liver function tests and full blood counts must be repeated weekly until the patient is stable. Blood pressure, pulse, and temperature records are also needed regularly and careful fluid balance records are essential. Body weight should be measured weekly, unless more frequent weighing is indicated, in order to monitor fluid status. If possible, trace element and vitamin levels should be measured on commencing ETF and patients on long term feeding should have periodic checks of vitamin and trace element status. Discussed in details in nutrition assessment part.
Critically ill patients should be given, as PN, a mixture consisting of amino acids, carbohydrates, (around 60% of the non-protein energy) and fat (around 40% of the non-protein energy) as well as electrolytes and micronutrients (Sacks et al.,2009).
.Critically ill patients should be nourished parenterally from the beginning of intensive care if they are unlikely to be adequately nourished orally or enterally even after 5–7 days.Accordingly, the indication for PN should be made
prospectively in critically ill patients. The number of days required to re-establish adequate enteral or oral nutrition should be considered at the beginning of the therapy. There are, at present, no established criteria, which could help in determining, with absolute certainty, which patients are to be nourished parenterally. Therefore, it cannot be avoided that occasionally there are patients on PN who are adequately nourished enterally sooner than expected, and some patients who unexpectedly deteriorate and an indication for PN is established too late ((Sacks et al., 2009).
ADA (American Diabetes Association) recommends for individuals with DM in a nonhealth care situation that blood glucose levels be maintained in the normal or as close to normal range as possible when safely indicated . For hospitalized patients, ADA recommends that blood glucose levels of critically ill individuals be maintained at 110 mg/dL (6.1 mM) and <140 mg/dL (7.8 mM) . For noncritically ill patients, the absence of clear evidence for specific blood glucose goals prevents a specific recommendation by the ADA. However, as the ADA notes, reasonable goals, if safely achievable, are a fasting glucose concentration of <126 mg/dL (7.0 mM) and all other random glucose assessments of <180-200 mg/dL «10.0-11.1 mM). This approach is based upon data that suggest outcomes among hospi-talized, non-critically ill patients, are improved if blood glucose
values are maintained at these levels (American Diabetes Association, 2008)
Over the past several years, different enteral for Over the past several years, different enteral formulations have been specifically developed for the patient with DM or hyperglycemia. With respect to available nitrogen and total energy, all of the currently available DSEF differ only marginally from the average standard enteral formula (SEF), and usually provide values rang-ing from approximately 18%-20% total kcal as protein (approximately 40-60 g/L) and approximately 1,000-1,500 kcal/L total energy(Chen & Peterson., 2009) .
The major differences between DSEF and SEF involve the relative amounts and percentages of total energy provided in the form of CHO and fat, and, differences in the amount and source of fiber (Table 1). Relative to the average SEF, the DSEF currently available provide a decreased amount of CHO, and an increased amount of fat. These relatively high fat, low CHO formulations yield values for DSEF that range from approximately 80-120 gIL CHO (35%-50% of total kcal) and approximately 30-60 gIL (35%-50% oftotal kcal) as fat Chen & Peterson., 2009).
Distribution of macronutrients in the diet for patients with DM has historically been 55%–60% carbohydrate (CHO), 25%-30% fat, and 10%-20% protein. However, in 2008, revised
recommendations from the ADA for weight loss include either a low-CHO or low-fat calorie-restricted diet up to one year. The ADA also recommends for patients on low-CHO diets, the routine monitoring of lipid profiles, renal function and protein intake (in those patients with nephropathy).. Also, as consistent with the general population, people with DM are encouraged to achieve the U.S. Department of Agriculture (USDA) recommendation of 14 g fiber/1000 kcals (American Society of Parenteral and Enteral Nutrition ASPEN 2009).