Growth of bacteria and fungi in parenteral nutrition solutions containing albumin

The ability of total parenteral nutrition (TPN) solutions containing albumin to support bacterial and fungal growth was studied. The following solutions were tested for microbial growth: (A) thioglycolate broth, (B) solution A with preservatives, (C) albumin 6.25 g in 500 ml 0.9% sodium chloride injections, (D) solution C with preservatives, (E) amino acid and dextrose TPN solution with magnesium sulfate and folic acid, (F) solution E with albumin 6.25 g in 500 ml, (G) amino acid and dextrose TPN solution with calcium gluconate and multivitamins, and (H) solution G with albumin 6.25 g in 500 ml. Each solution was inoculated with 1 X 10(5) bacteria/ml or 1 X 10(3) yeast/ml in 12 serial dilutions using minimum inhibitory concentration (MIC) plates. These were incubated at 37 degrees C for 48 hours, and cultures were visually rated on a scale of 0 (no growth) to 4 (maximal growth). Each culture was repeated for a total of 10 samples. Microbial growth was not affected by the low concentrations of preservatives available from the TPN additives. Undiluted TPN solutions were able to sustain fungal growth only. There was a significant increase in microbial growth in diluted TPN solutions containing albumin for S. aureus, C. albicans, T. glabrata, K. brier, S. marcescans, and E. coli. The presence of vitamins (solution G) impaired the ability of gram-negative bacteria to proliferate, and the addition of albumin (solution H) had no significant effect on the growth characteristics of the organisms in the solution. The presence of albumin had no effect on the growth of S. faecalis or Ps. aeruginosa. The addition of albumin to crystalline amino acid TPN solutions increases the potential of these solutions to support the growth of fungi and bacteria. Hence, it is recommended that albumin be administered separate from amino acid TPN solutions.

Stability of amino acids and the availability of acid in total parenteral nutrition solutions containing hydrochloric acid

The stability of amino acids and the availability of acid from total parenteral nutrition (TPN) solutions containing hydrochloric acid were studied. Hydrochloric acid in the concentrations of 40 (TPN 1), 60 (TPN 2), and 100 (TPN 3) meq/liter was added to TPN solutions (4.25% amino acids, 25% dextrose monohydrate) containing various electrolytes (TPN control). Amino acid concentrations were determined from one sample of each solution using a Technicon Automatic Amino Acid Analyzer. Samples were analyzed 24 hours after mixing and compared with the TPN control at 24 hours. Tryptophan was assayed using a specific colorimetric assay at 0, 6, 24, and 48 hours. The concentrations of proline (76.2 of control) and histidine (85.7% of control) wee decreased in TPN 3. This phenomenon appeared to be dependent upon the concentration of hydrochloric acid in the TPN solution. There was no appreciable loss of any of the other amino acids in the test solution as compared with the control. Tryptophan levels fell in both the TPN control and the test solutions independent of the hydrochloric acid concentration. The pH of the solutions decreased with increasing concentrations of hydrochloric acid from 5.87 in the TPN control to 3.18 in TPN 3. The titratable acidity increased with increasing concentrations of hydrochloric acid (28.21 meq/liter in the TPN control to 115.54 meq/liter in TPN 3). Concentrations of some amino acids decreased in the presence of hydrochloric acid. Because of the short-time period in which these solutions will usually be infused (4-24 hours), this probably has a negligible effect on patients' nutritional therapy. The availability of acid from these solutions makes this combination useful in treating severe metabolic alkalosis.

Monitoring protein requirements of the patient receiving hemodialysis and total parenteral nutrition

A method of determining nitrogen balance in patients receiving total parenteral nutrition (TPN) and hemodialysis was evaluated. Daily nitrogen intake (NI), pre- and postdialysis weight, BUN, and creatinine values were determined. Urea-nitrogen accumulation (UNA) was calculated as the increase in total body urea-nitrogen (g) between two consecutive hemodialysis procedures. Urea-nitrogen accumulation was substituted for urine urea-nitrogen excretion in the nitrogen balance formula, and nitrogen balance was estimated as NI minus UNA. The results from eight patients were evaluated separately based on the TPN formulations administered. Group 1 received solutions containing 15 g of amino acids and 350 g of dextrose. Group 2 received solutions with 42.5 g of amino acids and 350 g of dextrose. The nitrogen intake of Group 2 (9.4 +/- 4.4 g/day, mean +/- S.D.) was greater than Group 1 (2.3 +/- 1.2 g/day), but the UNA was approximately the same for both groups (10.6 +/- 6.5 and 9.8 +/- 7.9 g/day for Groups 2 and 1, respectively). Nitrogen balance estimates for Group 2 (-0.9 +/- 8.4 g/day) were greater than for Group 1 (-7.4 +/- 7.1 g/day) with four of the seven patients in Group 2 and none of the patients in Group 1 achieving a positive nitrogen balance. The rate of rise of BUN (19 mg/dl/day) was the same for both groups. By using estimated nitrogen balance values and changes in BUN levels and BUN-to-creatinine ratios, nitrogen use by patients receiving both TPN and hemodialysis can be monitored and adequate doses of amino acids can be provided.

Home parenteral nutrition programs

The technique of home parenteral nutrition (HPN) is becoming a more widely used method to treat patients who cannot eat for prolonged periods; to date, more than 500 patients have been trained nationwide. Training has been limited for the most part to larger centers which have more experience in providing this complex patient education. As this technique becomes more widely accepted, however, other less experienced health care professionals will be called upon to develop HPN training programs. For this reason, it is important to simplify these training programs, with initial attention directed toward the procedures used to prepare the total parenteral nutrition solution. The chance of potential errors can be reduced by using amino acid solutions with electrolytes included in the formulation. When possible, complexity can be reduced by administering vitamins and extra electrolytes orally. The teaching program can be simplified by developing or using existing training manuals, which standardize procedures so that consistent methods are taught and performed. The manual can serve as a reference for patient and teacher alike. Distribution of supplies can be simplified by employing commercially available shipment programs; but, while these are very convenient for the patient and pharmacy, the costs of such programs could be a limitation. Finally, the extensive work required to arrange reimbursement for services and supplies also can be simplified. Often a social worker can facilitate this process because of experience and training in dealing with payment problems. In addition, training fees should be negotiated with third party payors early in the development of HPN programs. By simplifying these basic elements in an HPN, the task of training patients is less imposing and can be made more widely available to those who need this treatment modality.

Clinical comparison of two 8.5% amino acid injection products

A comparative clinical trial of Travasol 8.5% without electrolytes and FreAmine II 8.5% was performed. Thirty-six patients were admitted to the double-blind study and assigned randomly to receive either Travasol (16 patients) or FreAmine II (20 patients). All patients had abnormal renal and liver function. Nitrogen balance was compared, and metabolic complications were monitored by evaluating BUN, serum creatinine, creatinine clearance, serum CO2, SGOT, SGPT, serum LDH, and serum alkaline phosphatase. There were no significant differences found in nitrogen balance of patients receiving either Travasol or FreAmine (p greater than 0.05). The Bun for days 1--5 in the Travasol group was significantly greater (p = 0.02), but the difference (3 mg/dl) was not considered clinically significant. All other comparative measurements of renal function, liver function, and acid-base balance remained the same throughout the study period (p greater than 0.05). Based on these results, the use of either FreAmine II or Travasol can promote positive nitrogen balance in a TPN patient population with normal renal and hepatic function with no difference in metabolic complications.

Albumin in TPN solutions: potential savings from a prospective review

As a result of the common usage of albumin in total parenteral nutrition (TPN) solutions at The Ohio State University Hospitals, a review of the use of this product was performed. Albumin therapy in 18 patients was evaluated using prospective criteria. Therapy was considered appropriate if the serum albumin level was less than or equal to 3.0 g%. Using these criteria, 12 of 18 patients (67%) received albumin in the TPN solution. Of these 12 patients, 7 received albumin unnecessarily. During the 3-week review, a total of 168 vials of 50 ml, 25% albumin (2100 g) were administered to patients with serum albumin concentrations greater than 3.0/100 ml at a cost of $6,014. Over a year, this could mean over $100,00 in costs which could be eliminated. Criteria for use of albumin in malnourished patients receiving TPN are not well established. This study demonstrated that developing simple criteria for the prospective review of albumin in TPN solutions and using them to monitor albumin therapy closely, can result in very significant cost savings to patients receiving TPN.