The incidence and clinical significance of intravenous fat emulsion contamination during infusion.

So that the actual contamination rate of intravenous fat emulsions, as well as the type of microbial contamination, could be quantified, 103 bottles of 10% fat emulsion were collected near infusion completion from patients' bedsides. All samples were cultured and compared according to actual hanging time, in addition to the amount and type of microbial contamination. Recovered organisms included Escherichia coli, Staphylococcus epidermidis, diphtheroids, and Micrococcus. Sample analysis failed to demonstrate significant differences in extrinsic microbial contamination rate or organism multiplication between samples infusing for less than or equal to 12 hr and those infusing longer. Although these products support microbial growth, the contaminants introduced into the infusate by environmental or touch contamination yielded minimal colony growth. No patient developed signs or symptoms of bacteremia during the study period. Therefore, infusion of intravenous fat emulsion products over extended periods of time in this study did not increase the risk of developing infectious complications.

Providing 24-hour nutrient infusions to critically ill patients.

The outcome of critically ill patients receiving total parenteral nutrient (TPN) therapy was evaluated, and the percentage of wasted TPN solutions administered as one-per-day (2- or 3-L) or multiple-per-day (750-mL or 1-L) infusions was determined. Between March 31 and June 1, 1984, all patients who were treated by the nutritional support service (NSS) and who met the study criteria were included in the study. The 24-hour nutrient content of each TPN solution was determined using a published method. Patient outcome was determined using TPN therapy data that were collected from the patients' medical charts and NSS records. To determine waste, all discarded TPN solutions were recorded. A total of 20 patients (10 men and 10 women) were included, representing 23.6% of the 76 patients who received TPN therapy during the study period. Study patients received 24-hour nutrient solutions for a mean of 16.4 +/- 12.9 days and required a mean of 3.9 +/- 4.6 days to reach sufficient metabolic stability to qualify for 24-hour infusions. During the study period, 56 (2.8 +/- 2.5 per patient) orders were changed. The percentage of wasted TPN solutions was low; 4.3% (17 of 1326) multiple-per-day and 1.7% (5 of 292) one-per-day solutions were wasted. Twenty-four-hour TPN solutions can be used successfully in critically ill patient populations.

Retinol-binding protein and prealbumin: useful measures of protein repletion in critically ill, malnourished infants.

Plasma prealbumin (PA) and retinol-binding protein (RBP) concentrations were serially measured in 25 critically ill, malnourished infants requiring parenteral nutrition to determine if these visceral protein markers are useful in assessing acute protein repletion. Significant increases in both proteins (p less than 0.05) were noted as early as 5 to 7 days after institution of parenteral nutrition and continued significantly above baseline values through 2 weeks of observation. Gestational development (in infants less than 4 weeks old) and mean protein intake influenced visceral protein responses. Appropriate for gestational age neonates had more rapid and quantitatively greater PA responses (p less than 0.05) than small for gestational age neonates. Small for gestational age neonates never exceeded baseline RBP responses. Average protein intake of less than or equal to 2 g/kg/day resulted in PA and RBP concentrations below baseline and significantly lower than infants on higher protein intakes (p less than 0.05), at the end of 2 weeks. Average calorie intake of greater than 100 cal/kg/day had no differential influence on PA or RBP when compared with infants on less calories. Prealbumin values correlated with RBP values observed simultaneously (r = 0.588, p less than 0.0001). We conclude that PA and RBP are useful measures of protein repletion in critically ill infants requiring parenteral nutrition.

Clinical effect of nonthrombotic total parenteral nutrition catheters.

Radiographic evidence of subclavian vein thrombosis has been shown to occur in 33% of total parenteral nutrition patients. This incidence can be significantly reduced to 8% when heparin is administered concomitantly in total parenteral nutrition solutions. To evaluate the thrombotic risk of a newly developed polyurethane catheter, 20 concurrent patient pairs were prospectively cannulated with either a standard polyethylene catheter plus heparin or a polyurethane catheter without heparin in a sequential statistical study. Radionuclide venograms (Tc99m) were performed within 72 hr of catheterization, at biweeky intervals, and at termination of total parenteral nutrition administration. No patient in either group developed clinical (pain, arm swelling, collateral veins) or venogram evidence of thrombosis after catheterization during an overall cannulation period of 820 days. Use of polyurethane catheters and elimination of heparin in total parenteral solutions may be particularly important since contraindications to heparin use are common. Additionally, heparin elimination can decrease admixture work and confusion (ie, subcutaneous heparin double dosing) without increasing the risk of subclavian vein thrombosis.

Nutritional support of patients with renal disease.

Current concepts in the nutritional support of patients with renal disease are reviewed. In chronic renal failure, alterations in fat, carbohydrate, and glycogen metabolism usually occur and may be worsened by acute illness. Total parenteral nutrient (TPN) therapy is rarely required unless complications occur. In contrast, acute renal failure is generally associated with hypovolemia, sepsis, soft tissue injury, and coagulation defects, all of which influence metabolism and extracellular fluid volume; the gluconeogenesis that often occurs in these patients masks the metabolic effects of uremia. Nutritional support of patients with renal disease aims at providing adequate nutrients while limiting accumulation of nitrogenous waste. Current concepts concerning essential amino acids (EAAs), nonessential amino acids (NEAAs), and urea recycling are reviewed. The caloric needs of patients with renal failure are assumed to be similar to those of other hospitalized patients. There is no clinically important advantage of using an EAA formulation rather than mixed (EAA and NEAA) amino acids. Since fluid restriction is recommended and protein use is improved with diets with a high calorie-to-nitrogen ratio, the use of TPN solutions with dextrose 350 g is recommended. If glucose intolerance is severe, fat should be considered as a calorie source. Recommendations for monitoring the metabolic status of patients with renal failure receiving nutritional support are reviewed. Monitoring the metabolic status of patients with renal disease is crucial to providing safe and effective nutritional therapy. There appears to be no clinically important advantage to amino acid products specially formulated for use in renal disease.