Glycemic control and nutrition in the intensive care unit

[Guidelines for specialized nutritional and metabolic support in the critically-ill patient. Update. Consensus of the Spanish Society of Intensive Care Medicine and Coronary Units-Spanish Society of Parenteral and Enteral Nutrition (SEMICYUC-SENPE): hyperglycemia and diabetes mellitus]

Hyperglycemia is one of the main metabolic disturbances in critically-ill patients and is associated with increased morbidity and mortality. Consequently, blood glucose levels must be safely and effectively controlled, that is, maintained within a normal range, avoiding hypoglycemia on the one hand and elevated glucose concentrations on the other. To accomplish this aim, insulin is often required, avoiding protocols designed to achieve tight glycemic control. To prevent hyperglycemia and its associated complications, energy intake should be adjusted to patients' requirements, avoiding overnutrition and excessive glucose intake. Protein intake should be adjusted to the degree of metabolic stress. Whenever patients require artificial feeding, the enteral route, if not contraindicated, should be used since parenteral nutrition is associated with a higher frequency of hyperglycemia and greater insulin requirements. Enteral nutrition should be administered early, preferably within the first 24 hours of admission to the intensive care unit, after hemodynamic stabilization. Specific diets for hyperglycemia, containing low glycemic index carbohydrates and fibre and enriched with monounsaturated fatty acids, can achieve good glycemic control with lower insulin requirements.

Understanding glycemic control in the critically ill: 2011 update

Intensive monitoring of blood glucose concentrations in critically ill patients has become a standard of care in intensive care units over the past 10 years, following the publication of a single-center randomized trial targeting euglycemia in postoperative patients. This article summarizes the literature describing the relationship between hyperglycemia and mortality in the critically ill, the main findings of the major interventional trials of intensive insulin therapy, the association between hypoglycemia and increased glycemic variability with adverse outcomes, and the impact of a preexisting diagnosis of diabetes. A framework for understanding dysglycemia in the critically ill, an approach that recognizes disturbances in the "3 domains" of glycemic control--hyperglycemia, hypoglycemia, and increased glycemic variability--is presented. Finally, practical considerations relating to the implementation of glycemic management protocols are discussed.

Clinical need for continuous glucose monitoring in the hospital

Automation and standardization of the glucose measurement process have the potential to greatly improve glycemic control, clinical outcome, and safety while reducing cost. The resources required to monitor glycemia in hospitalized patients have thus far limited the implementation of intensive glucose management to patients in critical care units. Numerous available and up-and-coming technologies are targeted for the hospital patient population. Advantages and limitations of these devices are discussed herewith in.

Relationship of serum C-reactive protein and blood glucose levels with injury severity and patient morbidity in a pediatric trauma population

PURPOSE

Serum markers of inflammation and of glucose production are known to reflect the immediate metabolic response to injury. We hypothesized that monitoring of the early C-reactive protein (CRP) and blood glucose (BG) concentrations would correlate with clinical morbidity and outcome measures in pediatric trauma patients.

METHODS

A five-year retrospective chart review of pediatric trauma patients admitted to our Level I pediatric trauma center was conducted to establish the relationships between early (first 3 hospital days) serum CRP and BG concentrations, Injury Severity Score (ISS), and hospital length of stay (HLOS). Statistical significance (P < 0.05) was determined using Student's t-test.

RESULTS

Forty-two trauma patients (8.0 +/- 5.2 years) were evaluated. The early inflammatory response (CRP >or= 10 vs <10 mg/dl) was significantly correlated to the glycemic response (BG;121 +/- 24 vs 97.3 +/- 14.2 mg/dl, P < 0.05). Severely injured patients (ISS >or= 25 vs <25) were significantly more hyperglycemic (BG;156 +/- 56.9 vs 125 +/- 31.6 mg/dL, P = 0.003). Both increased inflammatory response (CRP;8.1 +/- 6.4 vs 2.5 +/- 3.5 mg/dL) and increased glycemic response (BG;111 +/- 15.9 vs 97.4 +/- 11.7 mg/dL) were independently and significantly associated with prolonged hospitalization (HLOS > 7 vs <or=7 days, P < 0.05).

CONCLUSION

This study establishes a significant relationship between the early inflammatory and glycemic injury response and the association of that response with pediatric trauma patient morbidity and outcome measures.

Clinical experience with tight glucose control by intensive insulin therapy

OBJECTIVE

To describe the current status and the clinical data related to the effects of tight glucose control by intensive insulin therapy in critically ill patients.

DESIGN

Review article.

SETTING

University hospital.

PATIENTS

Medical and surgical critically ill patients in whom a correlation between blood glucose and outcome variables were searched.

INTERVENTIONS

Tight glucose control by intensive insulin therapy.

MEASUREMENTS AND MAIN RESULTS

In contrast to the decreases in mortality and to low severity of adverse effects reported when insulin rate was titrated to keep blood glucose between 80 and 110 mg/dL, the benefits were not confirmed in multicenter prospective studies. Retrospective data found an association between a mean blood glucose level of <140-150 mg/dL and improved outcome. Currently unanswered issues include the optimal target for blood glucose, the effects of high blood glucose variability, the risks and hazards of hypoglycemia, and the potential influence of the underlying disorder on the effects of tight glucose control.

CONCLUSIONS

Recommendations regarding the practical aspects of tight glucose control by intensive insulin therapy cannot be presently issued. An intermediate target level for blood glucose of 140-180 mg/dL seems to be associated with the lowest risk-to-benefit ratio.

Current controversies around tight glucose control in critically ill patients

PURPOSE OF REVIEW

This review updates our knowledge on the benefits and risks of tight glucose control by intensive insulin therapy in critically ill patients, as well as discussing unanswered questions related to the subject.

RECENT FINDINGS

At the cellular level, the toxic effects of elevated and highly variable glucose concentration are related to an increase in oxidative stress and to several toxic intracellular derivates generated as by-products of the glycolytic pathway. Clinically, several recent studies have suggested that the optimal target for blood glucose may be higher than the 'normal' values of 4.4-6.1 mmol/l for various categories of patients. Also, the variability in glucose level appears to be an important determinant of glucose toxicity. Conflicting data on the hazards of hypoglycaemia are emerging.

SUMMARY

Practical recommendations for the implementation of tight glucose control using intensive insulin therapy cannot be disseminated until questions relating to optimal blood glucose level and the corresponding categories of patients have been resolved. The issues of glucose variability and the most efficient method of preventing hypoglycaemia will probably represent important parameters for comparing the safety and quality of protocols used for tight glucose control.

Is it time for implementation of tight glycaemia control by intensive insulin therapy in every ICU?

The second study on tight glycaemia control by intensive insulin therapy (IIT) confirmed in medical intensive care unit patients the decrease in hospital mortality reported by the same team in the first IIT trial in surgical patients. However, methodological concerns, the high rate of hypoglycaemia in spite of the infusion of large doses of parenteral glucose and the frequent use of steroids presently preclude considering these results as recommendations in other intensive care units, but rather argue for the need for large-scale assessment of the IIT approach by multi-centre studies to confirm the efficacy and safety of this therapeutic modality.