Total parenteral nutrition and enteral nutrition in diabetes

New Insulin Analogues and Perioperative Care of Patients with Type 1 Diabetes

While insulin remains the mainstay of managing type 1 diabetes, much has changed over the last 15 years. These changes should help in managing patients with type 1 diabetes during the perioperative period. More flexible insulin therapy has three components: 1) basal, 2) prandial and 3) corrective. Many patients, particularly younger patients, are using genetically modified recombinant human insulin analogues. Two of these analogues, aspart and lispro insulin, are rapid-acting with faster onset and offset than subcutaneous regular insulin, allowing both prandial and corrective boluses. Other insulin analogues, particularly glargine and possibly detemir, have a flat profile of up to 24 hours, providing improved basal insulin delivery. Basal insulin can also be provided by a continuous subcutaneous infusion of rapid-acting insulin via a computerised pump that also provides boluses on demand. There is little evidence to help choose the best management of patients with type 1 diabetes during surgery. Some authors still recommend glucose-potassium-insulin infusions for all patients with type 1 diabetes. We challenge this approach, given the flexibility of the newer insulin analogues and delivery systems. We suggest that for many procedures, patients’ usual regimens can be maintained in the perioperative period, providing less disruption and, possibly, greater safety. Both hyperglycaemia and hypoglycaemia reflect poor management: we suggest a target glucose range of 5 to 10 mmol/l. The importance of frequently measuring blood glucose and appropriate responses cannot be overemphasised.

The addition of fiber and the use of continuous infusion decrease the incidence of diarrhea in elderly tube-fed patients in medical wards of a general regional hospital: a controlled clinical trial

GOALS

To determine if feeds high in fiber continuously administered might minimize diarrhea.

BACKGROUND

The addition of soluble fiber to enteral feedings has not consistently decreased diarrhea in controlled clinical trials, and the effect of the use of intermittent or continuous infusions on the rate of diarrhea is similarly controversial.

STUDY

We studied 148 of 160 selected elderly well-nourished patients with acute disease prohibiting oral intake in a controlled clinical trial in the setting of an internal medicine departments in a regional hospital who were divided into 4 groups and fed according to combinations of intermittent or continuous systems, with fiber-free or fiber rich formulas. The 5-day rate of diarrhea was defined as 2 liquid stools or 3 or more semisolid or liquid bowel movements during a 24-hour period. Other outcome variables included mortality, hospital days, prolonged hospitalization (over 20 d), fever, and stools positive for Clostridium difficile cytotoxin A/B.

RESULTS

The increased relative risk of the continuous/fiber-free, intermittent/fiber, and intermittent/fiber-free groups compared with the continuous/fiber group was 2.8 [95% confidence interval (CI)=1.0-8.1], 2.5 (95% CI=0.9-7.1), and 5.0 (95% CI=1.9-13.2), respectively. These findings were independent of age (>80 y), female sex, being treated with antibiotics for respiratory or urinary infections, receiving respiratory support, or being fully conscious. There were no significant differences in the other outcomes.

CONCLUSIONS

We conclude that in elderly well-nourished hospitalized patients with acute diseases prohibiting oral intake, continuous and closed enteral feedings with the addition of fiber is effective in reducing the rate of diarrhea.

Glycaemic control in type II diabetic tube-fed patients with a new enteral formula low in carbohydrates and high in monounsaturated fatty acids: a randomised controlled trial

OBJECTIVES

To investigate the effects of long-term treatment with a new enteral formula low in carbohydrates and high in monounsaturated fatty acids (MUFAs), in comparison with a standard formula, on glycaemic control in tube-fed type II diabetic patients.

DESIGN

Randomised, double-blind, controlled, multi-centre trial.

SETTING

Early rehabilitation centres, primary care and nursing facilities.

SUBJECTS

A total of 78 patients with insulin-treated type II diabetes with HbA(1C) > or =7.0% and/or fasting blood glucose >6.66 mmol/l, who required enteral tube feeding due to neurological dysphagia.

INTERVENTIONS

Patients received 113 kJ (27 kcal)/kg of body weight of either test feed or an isoenergetic, isonitrogenous enteral formula (control) for 12 weeks. Glycaemic control (total daily insulin dosage (IU), fasting blood glucose, and HbA(1C)) and gastrointestinal tolerance were monitored daily.

RESULTS

After 12 weeks, median values for changes from baseline were as follows (test group vs control group, 'data as available' analysis): total daily IUs -6.0 vs 0.0 (P=0.0024), fasting blood glucose (mmol/l) -1.59 vs -0.08 (P=0.0068); HbA(1C) (%) -0.8 vs 0.0 (P=0.0016). Both formulas were tolerated comparably.

CONCLUSIONS

This study indicates that in tube-fed insulin-treated type II diabetic patients, the new low-carbohydrate, high MUFA formula results in a more effective glycaemic control than the standard diet, while being comparable in safety.

Application of dietary fiber in clinical enteral nutrition: A meta-analysis of randomized controlled trials

AIM: To evaluate the effects of dietary fiber (DF) as a part of enteral nutrition (EN) formula on diarrhea, infection, and length of hospital stay.

METHODS: Following electronic databases were searched for randomized controlled trials about DF: Chinese Biomedicine Database (CBM), MEDLINE, EMBASE and Cochrane Controlled Trials Register. RevMan 4.1 was used for statistical analysis.

RESULTS: Seven randomized controlled trials with 400 pat-ients were included. The supplement of DF in EN was compared with standard enteral formula in five trials. Combined analysis did not show a significant reduction in occurrence of diarrhea, but there were valuable results for non-critically ill patients. Combined analysis of two trials observing the infection also did not show any valid evidence that DF could decrease the infection rate, though the length of hospital stay was reduced significantly.

CONCLUSION: Based on the current eligible randomized controlled trials, there is no evidence that the value of DF in the diarrhea can be proved. Though length of hospital stay was shortened by the use of DF, there is no available evidence in preventing infection by DF. Further studies are needed for evaluating the value of DF in EN.

The implementation of nutritional advice for people with diabetes

These consensus-based recommendations emphasize the practical implementation of nutritional advice for people with diabetes, and describe the provision of services required to provide the information. Important changes from previous recommendations include greater flexibility in the proportions of energy derived from carbohydrate and monounsaturated fat, further liberalization in the consumption of sucrose, more active promotion of foods with a low glycaemic index, and greater emphasis on the provision of nutritional advice in the context of wider lifestyle changes, particularly physical activity. Monounsaturated fats are now promoted as the main source of dietary fat because of their lower susceptibility to lipid peroxidation and consequent lower atherogenic potential. Consumption of sucrose for patients who are not overweight can be increased up to 10% of daily energy provided that this is eaten in the context of a healthy diet and distributed throughout the day [corrected]. Evidence is presented for the effectiveness of advice provided by trained dieticians. The increasing evidence for the importance of good metabolic control and the growing requirement for measures to prevent Type 2 diabetes in an increasingly obese population will require major expansion of dietetic services if the standards in National Service Frameworks are to be successfully implemented.

Postoperative management of the diabetic patient

Diabetic patients are at increased risk for adverse outcomes of surgery. These adverse outcomes are related to pre-existing complications of diabetes, especially atherosclerotic disease, nephropathy (and perhaps increased susceptibility to other renal toxins), and peripheral and autonomic neuropathy. Hyperglycemia is associated with likely risks for poorer wound healing, increased susceptibility to infection, and probable loss of administered nutrients through glycosuria. Insulin use has the flexibility of timing and dose in the postoperative management of most diabetic patients. The combinations of intermediate-acting and long-acting insulins and short-acting insulins usually are related to the experience and preferences of the treating physicians and allied health professionals. Intravenous insulin (always R) may be limited to administration in the ICU because of the need for frequent blood glucose monitoring and rapidity of glucose response to intravenous insulin. The use of short-acting insulin analogues has been shown to work well as premeal insulin or for rapidly treating marked hyperglycemia in the outpatient setting. Meal delivery in the hospitalized patient may not be timed as precisely as in the home situation. Nurses may be responsible for many patients. The rapid-acting analogues may be associated with increased risk for hypoglycemia in the hospitalized patient if insulin cannot be given immediately before a meal. These rapid-acting insulin analogues usually are limited to circumstances in which the patient can determine the dose and self-administer just before ingestion of the meal. The long-acting insulin analogues may not afford enough flexibility in many situations in which daily dosages changes are occurring in intermediate-acting and long-acting insulins. Oral glucose-lowering agent use in the postoperative state usually is limited to selected patients, including patients who have been on such agents before surgery, who have only mild elevations of blood glucose, who are able to ingest oral medications, and who do not have significant comorbid conditions (or significant risk for such conditions) that may be contraindications to use of such agents (see Table 3). Sulfonylureas and other insulin secretagogues (e.g., meglitinide, nateglinide) lower glucoses acutely. The risk for hypoglycemia is slightly less with the nonsulfonylurea agents. Efficacy and side effects limit the use of carbohydrase inhibitors for hospitalized patients. The glucose-lowering effects of biguanides and thiazolidinediones usually are not rapid enough for hospitalized patients who have never taken these medications. For patients who have been on a biguanide or thiazolidinedione before admission, these agents often are restarted in the postoperative period when oral intake of medications is possible and hepatic and renal function are stable. The hospital period affords an opportunity to review long-term management issues related to diabetes and its complications. Instruction on the importance of medical nutrition therapy, glycemic control, management of hypertension, dyslipidemia, and aspirin use as well as basic guidelines for foot care should be carried out during the hospitalization and at the time of discharge. Similarly, appropriate arrangements for medical nutrition therapy, general diabetes education (especially for newly diagnosed diabetic patients), and regular medical follow-up are important to ensure long-term, excellent surgical and medical outcomes.

Feeding the intensive care patient

The present review highlights recent findings (focusing on papers published between October 1999 and December 2000) in nutritional support of intensive care unit patients. During the past year, research focused on the use of enteral nutrition versus parenteral nutrition, and on the best composition of enteral nutrition and parenteral nutrition according to the clinical condition of the patient. With regard to enteral nutrition, the pH of nutritional support, the timing of administration and the technique of tube placement were debated. Immunomodulating agents and hormonal manipulations may improve outcomes of critically ill patients, but still warrant further research before they can be recommended for routine clinical use.

Preparing the azotemic diabetic patient for surgery

Azotemic diabetic patients have more risk of complications during or after surgery than those without diabetes and azotemia. These complications include infection, excessive bleeding, cardiovascular events, and electrolyte imbalance. The appropriate preoperative evaluation, measures to be taken to avoid the complications, and how to adequately manage blood sugar during surgery is discussed.