Roland N. Dickerson

A randomized trial of isonitrogenous enteral diets after severe trauma. An immune-enhancing diet reduces septic complications

OBJECTIVE The authors randomized patients to an enteral diet containing glutamine, arginine, omega-3 fatty acids, and nucleotides or to an isonitrogenous, isocaloric diet to investigate the effect of septic outcome. A third group of patients, without enteral access but eligible by severity of injury, served as unfed controls and were studied prospectively to determine the risk of infection. SUMMARY BACKGROUND DATA Laboratory and clinical studies suggest that diets containing specialty nutrients, such as arginine, glutamine, nucleotides, and omega-3 fatty acids, reduce septic complications. Unfortunately, most clinical trials have not compared these diets versus isonitrogenous, isocaloric controls. This prospective, blinded study randomized 35 severely injured patients with an Abdominal Trauma Index > or = 25 or a Injury Severity Score > or = 21 who had early enteral access to an immune-enhancing diet ([IED] Immun-Aid, McGaw, Inc., Irvine, CA; n = 17) or an isonitrogenous, isocaloric diet (Promote [Ross Laboratories, Columbus, OH] and Casec [Mead-Johnson Nutritionals, Evansville, IN]; n = 18) diet. Patients without early enteral access but eligible by severity of injury served as contemporaneous controls (n = 19). Patients were evaluated for septic complications, antibiotic usage, hospital and intensive care unit (ICU) stay, and hospital costs. RESULTS Two patients died in the treatment group and were dropped from the study. Significantly fewer major infectious complications (6%) developed in patients randomized to the IED than patients in the isonitrogenous group (41%, p = 0.02) or the control group (58%, p = 0.002). Hospital stay, therapeutic antibiotics, and the development of intra-abdominal abscess was significantly lower in patients receiving the IED than the other two groups. This improved clinical outcome was reflected in reduced hospital costs. CONCLUSIONS An IED significantly reduces major infectious complications in severely injured patients compared with those receiving isonitrogenous diet or no early enteral nutrition. An IED is the preferred diet for early enteral feeding after severe blunt and penetrating trauma in patients at risk of subsequent septic complications. Unfed patients have the highest complication rate.

Hypocaloric enteral tube feeding in critically ill obese patients

OBJECTIVE We respectively compared the nutritional and clinical efficacies of eucaloric and hypocaloric enteral feedings in 40 critically ill, obese patients admitted to the trauma or surgical intensive care unit. METHODS Adult patients, 18 to 69 years old, with weights greater than 125% of ideal body weight, normal renal and hepatic functions, and who received at least 7 d of enteral tube feeding were studied. Patients were stratified according to feeding group: eucaloric feeding (>or=20 kcal/kg of adjusted weight per day; n = 12) or hypocaloric feeding (<20 kcal/kg of adjusted weight per day; n = 28). The goal protein intake for both groups was approximately 2 g/kg of ideal body weight per day. Clinical events and nutrition data were recorded for 4 wk. RESULTS Patients were similar according to sex, age, weight, body mass index, Second Acute Physiology and Chronic Health Evaluation score, Trauma score, and Injury Severity Score. The hypocaloric feeding group received significantly fewer calories than the eucaloric group (P<or= 0.05). The hypocaloric group had a shorter stay in the intensive care unit (18.6 +/- 9.9 d versus 28.5 +/- 16.1 d, P < 0.03), decreased duration of antibiotic therapy days (16.6 +/- 11.7 d versus 27.4 +/- 17.3 d, P < 0.03), and a trend toward a decrease in days of mechanical ventilation (15.9 +/- 10.8 d versus 23.7 +/- 16.6 d, P = 0.09). There was no statistically significant difference in nitrogen balance or serum prealbumin response between groups. CONCLUSION These data suggest that hypocaloric enteral nutrition support is as least as effective as eucaloric feeding in critically ill, obese patients.

Resting energy expenditure in patients with pancreatitis.

ObjectiveTo assess the resting energy-expenditure of hospitalized patients with pancreatitis. DesignProspective, case-referent study. SettingNutrition support service in a university tertiary care hospital. PatientsPatients referred to the Nutrition Support Service with the diagnosis of pancreatitis. Excluded from study entry included those with cancer, obesity (>150% ideal body weight), those measured within 3 postoperative days, or patients requiring ventilator support with an Fio2 of >0.5. Forty-eight patients with either acute pancreatitis (n = 13), chronic pancreatitis (n = 24), acute pancreatitis with sepsis (n = 7), or chronic pancreatitis with sepsis (n = 7) were studied. The two septic groups were combined into a single pancreatitis-with-sepsis group, since no significant differences among measured variables were observed between individual septic groups. InterventionsNone. Measurements and Main ResultsResting energy expenditure was measured by indirect calorimetry and compared with the predicted energy expenditure, as determined by the Harris-Benedict equations. Resting energy expenditure (percent of predicted energy expenditure) was significantly (p < .02) greater for patients with pancreatitis complicated by sepsis (120 ± 11%) compared with the nonseptic chronic pancreatitis group (105 ± 14%). Resting energy expenditure for the nonseptic acute pancreatitis patients (112 ± 17%) was not significantly different from the other groups. The septic pancreatitis group had the largest percentage (82%) of hypermetabolic (resting energy expenditure >110% of predicted energy expenditure) patients, whereas 61% and 33% of the acute and chronic pancreatitis groups were hypermetabolic, respectively (p < .02). ConclusionsResting energy expenditure is variable in patients with pancreatitis (77% to 139% of predicted energy expenditure). The Harris-Benedict equations are an unreliable estimate of caloric expenditure. Septic complications are associated with hypermetabolism and may be the most important factor influencing resting energy expenditure in pancreatitis patients. (Crit Care Med 1991; 19:484)

Sequential single doses of cisapride, erythromycin, and metoclopramide in critically ill patients intolerant to enteral nutrition: A randomized, placebo-controlled, crossover study

Objective: To evaluate the comparative efficacy of enteral cisapride, metoclopramide, erythromycin, and placebo for promoting gastric emptying in critically ill patients with intolerance to gastric enteral nutrition (EN). Design: A randomized, crossover study. Setting: Adult medical intensive care unit at a university‐affiliated private hospital and trauma intensive care unit at a university teaching hospital. Patients: Ten adult, critically ill, mechanically ventilated patients not tolerating a fiber‐containing EN product defined as a single aspirated gastric residual volume >150 mL or two aspirated gastric residual volumes >120 mL during a 12‐hr period. Interventions: Patients received 10 mg of cisapride, 200 mg of erythromycin ethylsuccinate, 10 mg of metoclopramide, and placebo as 20 mL of sterile water every 12 hrs over 48 hrs. Acetaminophen solution (1000 mg) was administered concurrently. Gastric residual volumes were assessed, and plasma acetaminophen concentrations were serially determined by TDx between 0 and 12 hrs to evaluate gastric emptying. Measurements and Main Results: Gastric residual volumes during the study were not significantly different between agents. No differences in area under the concentration vs. time curve or elimination rate constant were identified between agents. Metoclopramide and cisapride had a significantly shorter mean residence time of absorption than erythromycin (6.3 ± 4.5 [SEM] mins and 10.9 ± 5.8 vs. 30.1 ± 4.5 mins, respectively [p < .05]). Metoclopramide (9.7 ± 15.3 mins) had a significantly shorter time to peak concentration compared with erythromycin and placebo (60.7 ± 8.1 and 50.9 ± 13.5 mins, respectively [p < .05]). The time to onset of absorption was significantly shorter for metoclopramide vs. cisapride (5.7 ± 4.5 vs. 22.9 ± 5.7 mins [p < .05]). Conclusion: In critically ill patients intolerant to EN, single enteral doses of metoclopramide or cisapride are effective for promoting gastric emptying in critically ill patients with gastric motility dysfunction. Additionally, metoclopramide may provide a quicker onset than cisapride.

A.S.P.E.N. Clinical Guidelines Nutrition Support of Hospitalized Adult Patients With Obesity

BACKGROUND Due to the high prevalence of obesity in adults, nutrition support clinicians are encountering greater numbers of obese patients who require nutrition support during hospitalization. The purpose of this clinical guideline is to serve as a framework for the nutrition support care of adult patients with obesity. METHOD A systematic review of the best available evidence to answer a series of questions regarding management of nutrition support in patients with obesity was undertaken and evaluated using concepts adopted from the Grading of Recommendations, Assessment, Development and Evaluation working group. A consensus process, that includes consideration of the strength of the evidence together with the risks and benefits to the patient, was used to develop the clinical guideline recommendations prior to multiple levels of external and internal review and approval by the A.S.P.E.N. Board of Directors. QUESTIONS (1) Do clinical outcomes vary across levels of obesity in critically ill or hospitalized non-intensive care unit (ICU) patients? (2) How should energy requirements be determined in obese critically ill or hospitalized non-ICU patients? (3) Are clinical outcomes improved with hypocaloric, high protein diets in hospitalized patients? (4) In obese patients who have had a malabsorptive or restrictive surgical procedure, what micronutrients should be evaluated?

Manganese intoxication and parenteral nutrition

Since the introduction of long-term parenteral nutrition for patients with intestinal failure, morbidity due to inadequate replacement of micronutrients has been well described. More recently, recognition of hypermanganesemia and its associated complications has become an issue in the patient receiving long-term parenteral nutrition. The intent of this report is to provide a brief overview of manganese in parenteral nutrition and offer some practical suggestions to avoid manganese intoxication. A normal 70-kg person contains about 12 to 20 mg of manganese, which is widely distributed in tissues as the two manganesecontaining metalloenzymes, pyruvate carboxylase and superoxide dismutase, both of which are located in the mitochondria.1,2

Treatment of hypophosphatemia in patients receiving specialized nutrition support using a graduated dosing scheme : results from a prospective clinical trial

OBJECTIVE To determine the safety and efficacy of a graduated dosing scheme of phosphorus replacement therapy in patients with hypophosphatemia receiving specialized nutrition support. DESIGN Prospective clinical trial. SETTING A 455-bed tertiary care institution, with Level I trauma designation. PATIENTS Seventy-eight adult patients, followed and co-managed by a multidisciplinary Nutrition Support Service, with a serum phosphorus concentration of < 3 mg/dL (< 0.97 mmol/L) and no evidence of renal insufficiency, calcium or parathyroid disorders, or obesity. INTERVENTIONS Patients were enrolled into one of three categories based on their serum phosphorus concentration: mild hypophosphatemia (2.3 to 3 mg/dL [0.74 to 0.97 mmol/L]), moderate hypophosphatemia (1.6 to 2.2 mg/dL [0.52 to 0.71 mmol/L]), or severe hypophosphatemia (< 1.5 mg/dL [< 0.48 mmol/L]). Each patient received one intravenous phosphorus bolus dose, based on the assigned category of hypophosphatemia, according to a graduated dosing scheme: 0.16 mM/kg (mild), 0.32 mM/kg (moderate), or 0.64 mM/kg (severe). Serum/blood concentrations of phosphorus, calcium, albumin, magnesium, urea nitrogen, and creatinine were measured for three consecutive days. MEASUREMENTS AND MAIN RESULTS Sixty-seven patients completed the protocol. There were 31 patients with mild hypophosphatemia, 22 patients with moderate hypophosphatemia, and 14 patients with severe hypophosphatemia. Serum phosphorus concentrations increased significantly (p < .001) in all groups after the phosphorus bolus: 2.6 +/- 0.6 to 3.3 +/- 0.6 mg/dL (0.84 +/- 0.19 to 1.1 +/- 0.19 mmol/L) for the mild group; 1.9 +/- 0.6 to 2.7 +/- 0.6 mg/dL (0.61 +/- 0.19 to 0.87 +/- 0.19 mmol/L) for the moderate group; 1.3 +/- 0.8 to 2.3 +/- 0.8 mg/dL (0.42 +/- 0.26 to 0.74 +/- 0.26 mmol/L) for the severe group. There were no clinically significant changes in serum/blood calcium, albumin, urea nitrogen, or creatinine concentrations and no adverse reactions to the phosphorus regimens throughout the 3-day study period. CONCLUSION The graduated dosing scheme of phosphorus replacement therapy is both safe and efficacious in patients receiving specialized nutrition support.

Early Nutrition Support Modifies Immune Function in Patients Sustaining Severe Head Injury

BACKGROUND Immunosuppression after severe head injury has been characterized by a depressed CD4 (T-helper/inducer)-CD8 (T-suppressor/cytotoxic) ratio and decreased T-lymphocyte responsiveness. Some investigators propose that this immunocompromized state is the result of an injury-associated hypermetabolic response and inadequate nutrient delivery during the immediate postinjury recovery phase. Previous observations from our institution demonstrated a preserved CD4-CD8 ratio in severe closed-head injury (CHI) patients receiving early parenteral nutrition (PN). It was unclear whether early PN or other aspects of patient care eliminated the characteristic depression in cellular immunity. The purpose of this study was to further investigate the effect of early PN on the immune function of CHI patients. METHODS Nine patients sustaining severe CHI were prospectively randomized to either early PN (n = 4) at day 1 or delayed PN (n = 5) at day 5. Total nutrient administration was delivered at 2 g of protein/kg per day and 40 nonprotein kcal/kg per day for at least the first 14 days of hospitalization. Analysis for T-lymphocyte expression of CD4 and CD8 cell surface antigens and interleukin-6 was performed on days 1, 3, 7, and 14 of hospitalization. T-lymphocyte activation in response to stimulation by concanavalin A (Con A), phytohemagglutinin (PHA), and pokeweed mitogens (PWM) was also assessed on these days. RESULTS Significant increases in total CD4 cell counts (2048 +/- 194 to 2809 +/- 129 vs 1728 +/- 347 to 1825 +/- 563, p < .05) and CD4% (42.6 +/- 4.4% to 56.2 +/- 2.6% vs 36.6 +/- 6.6% to 36.6 +/- 11.3%, p < .05) were observed at day 14 in patients receiving early vs delayed PN. An improved lymphocyte response from baseline to day 14 after Con A stimulation was demonstrated in the early PN group (3850 +/- 1596 to 16144 +/- 5024 cpm, p < .05). A significant rise in the CD4-CD8 ratio over baseline to day 14 was also noted in the early PN group (1.43 +/- 0.17 to 2.38 +/- 0.54, p < .05). CONCLUSIONS The early aggressive nutrition support of CHI patients appears to modify immunologic function by increasing CD4 cells, CD4-CD8 ratios, and T-lymphocyte responsiveness to Con A.

Hypocaloric feeding of obese patients in the intensive care unit.

Purpose of reviewGiven the increased awareness of the detrimental complications of overfeeding, particularly hyperglycemia, the safety and efficacy of specialized nutritional support for the critically ill obese patient is of major concern. The intent of this review is to provide the scientific foundation, supporting and conflicting literature, for the implementation of hypocaloric, high-protein specialized nutritional support for acutely ill, hospitalized patients with obesity. Recent findingsSimilar anabolic equivalencies can be achieved with hypocaloric, high-protein nutritional support compared with a more traditional higher calorie, lower protein regimen. The provision of additional calories worsens hyperglycemia, results in a further accumulation of fat mass, and increases the potential for overfeeding without significant net protein anabolism gain. SummaryThe current literature indicates that hypocaloric, high-protein enteral or parenteral nutrition is promising as the standard of practice for the metabolic support of the critically ill obese patient. The achievement of net protein anabolism and the avoidance of overfeeding complications are the primary goals, with fat weight loss a welcome secondary benefit. Abbreviations BMI: body mass index; ICU: intensive care unit; REE: resting energy expenditure.

Nutrition Therapy of the Severely Obese, Critically Ill Patient: Summation of Conclusions and Recommendations

This report compiles the conclusions and recommendations for nutrition therapy of the obese, critically ill patient derived by the group of experts participating in this workshop on obesity in critical care nutrition. The recommendations are based on consensus opinions of the group after review of the current literature. Obesity clearly adds to the complexity of nutrition therapy in the intensive care unit (ICU). Obesity alters the incidence and severity of comorbidities, tolerance of the prescribed regimen, and ultimately patient outcome through the course of hospitalization. Although the basic principles of critical care nutrition apply to the obese ICU patient, a high-protein, hypocaloric regimen should be provided to reduce the fat mass, improve insulin sensitivity, and preserve lean body mass. The ideal enteral formula should have a low nonprotein calorie to nitrogen ratio and have a variety of pharmaconutrient agents added to modulate immune responses and reduce inflammation.