Metabolic response and parenteral nutrition in trauma, sepsis, and burns

Comparative Quantitative Acid-Base Analysis in Coronary Artery Bypass, Severe Sepsis, and Diabetic Ketoacidosis

The main objective of this study was to assess the relationship of standard base excess (SBE) to delta strong ion difference effective (ΔSIDe) in critical illness. Critical illness is characterized by variable plasma nonvolatile weak acid components (ΔA-), and SBE becomes discordant with ΔSIDe. The author hypothesized that both acid-base models are equivalent when SBE and ΔSIDe are corrected for ΔA-. A retrospective chart review was performed to assess this hypothesis by looking at changes in SBE, ΔSIDe, and ΔA-in 30 coronary artery bypass graft surgery patients, 30 severe sepsis patients, and 15 diabetic ketoacidosis patients. SBE equals the sum of the ΔSIDe and ΔA-. The SBE quantifies the magnitude of the metabolic acid-base derangement, the ΔSIDe quantifies the plasma strong cation/anion imbalance, and the ΔA-quantifies the magnitude of the hypoalbuminemic alkalosis. The partitioning of SBE into physicochemical components can facilitate analyses of complex acid-base disorders in critical illness.

Antifactor Xa Levels in Four Patients with Burn Injuries Who Received Enoxaparin to Prevent Venous Thromboembolism

Four patients with severe burn injuries received enoxaparin 40 mg twice/day subcutaneously for the prophylaxis of venous thromboembolism (VTE). Peak antifactor Xa levels were measured 4 hours after administration of a dose, and trough antifactor Xa levels were measured 30 minutes before the next scheduled dose. Ultrasonography was performed once/week to assess the presence of VTE. Any occurrence of major bleeding was documented in the patients' charts. All patients had trough antifactor Xa levels below 0.1 U/ml. Enoxaparin dosages were subsequently adjusted to achieve trough antifactor Xa levels of 0.1-0.2 U/ml. This required dosages higher than those typically recommended for VTE prophylaxis (40 mg every 24 hrs or 30 mg every 12 hrs). One patient needed more than 60 mg every 12 hours. No patient had a venous thromboembolic event or major bleeding. The low antifactor Xa levels that were observed suggest that a reduced dose-response relationship may exist between subcutaneously administered enoxaparin and antifactor Xa activity in patients with severe burn injuries. Prospective studies should be performed to further investigate this relationship.

Early versus late enteral feeding in patients with acute cervical spinal cord injury: a pilot study

STUDY DESIGN

A prospective randomized clinical pilot study to compare early versus late enteral feeding in patients with acute cervical spinal cord injury.

OBJECTIVES

To compare the incidence of infections in patients with acute cervical spinal cord injury who received early versus late enteral feeding. Secondary objectives included assessing nutritional status, feeding tolerance, the number of ventilator hours, and acute-care hospital length of stay.

SUMMARY OF BACKGROUND DATA

Early nutritional support has been found to be beneficial in critically ill patients. However, the same benefits may not be realized in patients with acute cervical spinal cord injury because of their unique nutritional challenges.

METHODS

Eligible patients were randomized to early feeding (initiated before 72 hours after injury) and late (initiated more than 120 hours after injury). Patients were stratified on the basis of their neurologic level. Patients were assessed daily for the first 15 days. After that time, infections (according to Center for Disease Control criteria), ventilator hours, and length of acute-care hospital stay were tracked.

RESULTS

Twenty-three patients met the eligibility criteria, and 17 patients were included in the analysis. There were 7 patients in the early group and 10 in the late group. The early group had a mean of 2.4 +/- 1.5 infections compared with the late group, which had a mean of 1.7 +/- 1.1 infections. Secondary outcomes were not substantially different between the two groups.

CONCLUSIONS

This pilot study failed to detect any differences in the incidence of infection, nutritional status, feeding complications, number of ventilator hours, or length of stay between patients receiving early versus late initiation of enteral feeding. These data will assist in the determination of an adequate sample size for future studies.

Nutritional support for the burn-injured patient

The nutritional needs of the bum-injured patient are exaggerated and change constantly with the patient's stage of convalescence. Nurses working closely with other members of the health care team, specifically the nutritional specialist, can positively affect the patient's survival by optimizing the nutritional assessment,delivering enteral feedings that meet established goals,minimizing the negative consequences of hyperglycemia, and minimizing unnecessary energy expenditures by the patient. Adequate nutritional is required for wound healing, immunocompetence, and, ultimately,patient survival.