The growth of microorganisms in total parenteral nutrition admixtures

Total nutrient admixtures (TNAs) containing glucose, amino acids, and lipid emulsion in one container and amino acid/dextrose solutions [conventional total parenteral nutrition (TPN) formulations] were studied in a controlled laboratory experiment for their ability to support the growth of microorganisms. Both TNA and conventional TPN formulations for peripheral and central venous administration with standard additives were inoculated with microorganisms to provide 10(1)-10(2) colony-forming units/ml (CFU/ml) of Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Candida albicans. The admixtures were stored at room temperature and samples for quantitative microbiology were taken at time 0, 6, 12, 24, 48, 72, and 96 hr. K. pneumoniae, E. coli, and P. aeruginosa were able to proliferate in central TNAs, but the growth of these organisms was retarded in conventional TPN solutions. In the peripheral formulations, K. pneumoniae and E. coli proliferated in both the TNA and conventional TPN systems, whereas P. aeruginosa grew well only in the peripheral TNA. S. epidermidis was not able to grow in any admixtures tested; however, C. albicans grew well in all admixtures, but growth was slower in the conventional central TPN. In conclusion, peripheral and central TNAs supported the growth of microorganisms significantly better than conventional TPN solutions.     

Emulsion stability in total nutrient admixtures containing a pediatric amino acid formulation.

Emulsion stability of total nutrient admixtures containing TrophAmine amino acid injection admixed with Intralipid, Nutrilipid, and Liposyn II was studied. High and low electrolyte concentrations were added to each total nutrient admixture before storage at 4 degrees C for 48 hours then at 20-22 degrees C for 24 hours. Stability studies were also performed on total nutrient admixtures containing higher concentrations of fat emulsion and total nutrient admixtures with added cysteine hydrochloride and carnitine. High electrolyte concentrations only were added to these total nutrient admixtures before being stored refrigerated for 24 hours then at room temperature for 24 hours. Visual assessment, pH determination, and particle size analysis were performed immediately after compounding and after refrigerated and room temperature storage. Particle size was assessed by measuring the mean diameter of the fat emulsion and the percent of oil volume in particles greater than 5 microns. Repeated-measures analyses of variance were used to determine significance of type or concentration of fat emulsion, electrolyte concentrations, or time on mean diameter or percent particles greater than 5 microns. There were minimal changes in pH values over time. Creaming was observed in all total nutrient admixtures at all sampling times except time zero. This was reversible upon agitation. Results of particle size analysis over time indicated little change in mean diameter or percent particles greater than 5 microns. These minimal changes did not seem to be clinically significant. It is concluded that total nutrient admixtures prepared with this pediatric amino acid formulation are stable when prepared and stored as reported.     

Physicochemical stability of two types of intravenous lipid emulsion as total nutrient admixtures

BACKGROUND: Recent data have demonstrated that total nutrient admixtures (TNAs) are unstable when the percentage of fat (PFAT) globules >5 microm in diameter constitute >0.4% of the total fat present and therefore can be considered pharmaceutically unfit for human administration. METHODS: We studied five nutritionally balanced TNAs using two different products of different oil composition designed to feed adult patients weighing 40 to 80 kg in 10 kg increments, which were given in final volumes equal to 25 mL/kg. Final concentrations of amino acids, dextrose, and lipids were held constant for each weight level. To provide cationic stress within clinical limits, calcium and magnesium were given in amounts equal to three times the usual daily dose, at 15 mmol each. Five TNAs were made in duplicate and for each product (n = 20) and studied over 5 days. Lipid droplet counts were determined by laser light extinction and conducted at five intervals; immediately after preparation at time 1 (T1), after 4 days at 4 degrees C +/- 2 degrees C (T2), and then at 6 (T3), 24 (T4), and 30 (T5) hours during storage at 25 degrees C +/- 1 degree C. At T3, a simulated patient infusion, set at a rate to deliver the entire volume over the next 24 hours, was begun. Samples taken at T3, T4, and T5, equal to 0, 18, and 24 hours, respectively, of the simulated patient infusion, were collected from the terminal infusion port of the i.v. administration set. Mean particle size (MPS) was determined by dynamic light scatter at T1, T3, and T5. Dependent variable analyses included the PFAT globules > 1.75 and 5 microm and MPS. A repeated-measure two-way ANOVA assessing treatment and time was performed. RESULTS: The MCT/LCT-based TNAs had significantly fewer enlarged fat globules >1.75 microm (p < .0001) and >5 microm (p = .046), and smaller MPS (p < .0001) than TNAs made with the pure LCT emulsion. Of the 20 TNAs studied, 4 demonstrated visible evidence of instability (ie, heavy creaming or free oil), each occurring on day 5 only with the 70- and 80-kg LCT-based TNAs, and no evidence of instability with admixtures prepared from MCT/LCT lipid emulsions (chi2 analysis: p < .05). CONCLUSIONS: Because the final macronutrient concentrations were held constant, the instability seen with the LCT-based TNAs of higher volumes may result from dilution of the electrolyte concentrations that unfavorably alters the electrical double layer and irreversibly commits the emulsion to an unstable state. The greater physicochemical stability achieved with the MCT/LCT-based TNAs, in turn, likely results from the smaller lipid droplet sizes, which may be an inherent property of MCTs.     

Comparison of total nutrient admixture stability using two intravenous fat emulsions, Soyacal and Intralipid 20%

The safe clinical use and physical stability of a total nutrient admixture (TNA) system containing a soybean oil emulsion (Intralipid) has been reported. A study was conducted to compare the physical stability of four admixtures which were divided into two groups based upon the ratios (1:1:1 and 2:1:1) of amino acids (8.5%), dextrose (70%), and fat emulsion (20%). The fat component in each group contained either a new soy bean fat emulsion, Soyacal, or Intralipid. The quantities of all electrolytes, trace elements and vitamin additives were the same. All solutions were stored at 4 degrees C for 28 days and then held at ambient temperature for 5 days for a total 33-day study period. Each admixture was serially analyzed on days 0, 1, 2, 3, 5, 7, 14, 21, 28, 29, 30, 31, 32, and 33. Examination of gross visual appearance and determinations of pH were performed. Osmolality was measured by means of freezing point depression (Advanced Digimatic Osmometer, Advanced Instruments, Inc., Needham Heights, MA). A Brookhaven particle analyzer was used to measure lipid particle size and particle size distribution. Electron and light microscopy were used to verify maximum particle size and distribution on days 0, 7, 14, 21, 28, and 29. The type of lipid emulsion used did not affect the pH or osmolality of the admixtures. Admixtures prepared with the 2:1:1 ratio had slightly higher pH (0.07) and lower osmolality (350 mOsm/kg). The range of mean diameters for the admixtures prepared with Soyacal and Intralipid were 0.283 to 0.310 micron and 0.314 to 0.351 micron, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hepatic Indicators of Oxidative Stress and Tissue Damage Accompanied by Systemic Inflammation in Rats Following a 24‐Hour Infusion of an Unstable Lipid Emulsion Admixture

Background: Use of lipid emulsions in parenteral nutrition therapy is an important source of daily energy in substitution of potentially harmful glucose calories when given in excess in the intensive care unit. When added to parenteral nutrition (PN) admixtures as a total nutrient admixture (TNA), the stability and safety of the emulsion may be compromised. Development of a rat model of a stable vs unstable lipid infusion would enable a study of the potential risk. Design: Prospective, randomized, controlled study. Methods: Surgical placement of a jugular venous catheter for the administration of TNAs was performed. Two groups were studied: a stable or s‐TNA (n = 16) and an unstable or u‐TNA (n = 17) as a 24‐hour continuous infusion. Stability of TNAs was determined immediately before and after infusion using a laser‐based method approved by the United States Pharmacopeia. Results: Blood levels of aspartate aminotransferase, glutathione‐S‐transferase, and C‐reactive protein were significantly elevated in u‐TNA vs s‐TNA (P < .05). Also, liver tissue concentrations of malondialdehyde were significantly higher in the u‐TNA group (P < .05), and triglyceride tissue levels were also higher in u‐TNA and approached statistical significance (P = .077). Conclusions: Unstable lipid infusions over 24 hours produce evidence of hepatic accumulation of fat associated with oxidative stress, liver injury, and a low‐level systemic inflammatory response.     

Effect of amino acid solutions on total nutrient admixture stability

The stability of total nutrient admixture (TNA) systems containing a soybean oil emulsion (Soyacal) has been reported with only one amino acid (AA) solution. This study was conducted to compare the physical stability of 10 TNA systems varied only by the AA solution used. All systems contained electrolytes, vitamins, trace elements, and heparin. The volume ratios of AA, dextrose 70% and lipid emulsion 20% were 1:1:1. Solutions were stored at 4 degrees C for 14 days and then held at ambient temperature for an additional 4 days. Each TNA was serially analyzed on days 0, 1, 3, 5, 7, 14, 15, 16, 17, and 18 for gross visual appearance, pH, osmolality, mean particle diameter, and particle size distribution. The AA solutions evaluated include: Travasol 8.5% and 10%; Aminosyn 8.5% and 10%, Aminosyn RF 5.2%; FreAmine III 8.5% and 10%; FreAmine HBC 6.9%; HepatAmine 8.0%; and NephrAmine 5.4%. The pH values of the Aminosyn solutions were lower than those of other products; however, the pH values of all TNA systems were greater than 5.7, which supported particle stability. The osmolality was not affected by the AA solutions. Based upon particle size distribution, 95% of all particles were less than 0.608 micron in diameter, with means ranging from 0.286 micron to 0.309 micron. The largest particle observed by light microscopy was 6.9 micron. These data indicate that TNA systems prepared with the 10 AA solutions and Soyacal 20% are physically stable.     

儿科用静脉营养液中加入蔗糖铁对脂肪乳剂稳定性的影响

目的评估静脉营养液（TNA）中加入蔗糖铁对脂肪乳剂稳定性的影响。方法根据静脉营养配制操作规范在100mlTNA中分别加入0、0．25、0．50、0．75、1．00mg铁剂,每组各10袋。在0、24、48、72h时,采用扫描电镜观察各组脂肪颗粒直径,计算出直径〉0．5μm颗粒的百分比;并测定各组TNA的pH值及渗透浓度。结果不同时间点各组TNA的脂肪颗粒直径、直径〉0．5μm的颗粒百分比、pH值及渗透浓度差异均无统计学性意义（P均〉0．05）。在72h内,各组脂肪颗粒平均直径均〈0．5μm,各组均未见到直径〉5μm的脂肪颗粒。结论含蔗糖铁浓度0．25—1．00mg／100ml的TNA是稳定的。     

Effect of Intralipid, amino acids, container, temperature, and duration of storage on vitamin stability in total parenteral nutrition admixtures

This study was designed to determine the stability of certain vitamins added to total parenteral nutrition (TPN) admixtures with or without Intralipid iv fat emulsion and with each of four amino acid solutions stored in either glass bottles or plastic bags at either ambient room (25 degrees C) or refrigerator (5 degrees C) temperature for a 48-hr period. Riboflavin and folacin were not affected by the experimental conditions. The presence of Intralipid resulted in higher levels of vitamin E due to Intralipid's inherent vitamin E content; no other experimental conditions affected vitamin E. Thiamin levels decreased in admixtures containing the amino acid solution C and stored at 25 degrees C. Vitamin A levels were lower in admixtures stored in plastic but were maintained in admixtures containing Intralipid and stored in glass bottles at either temperature. Vitamin C levels were maintained in admixtures stored at 5 degrees C for all experimental conditions. The greatest vitamin C losses occurred in admixtures containing amino acid solutions C or D stored in plastic bags, or containing D stored in glass bottles at 25 degrees C.     

脂肪乳剂在全合一营养液中的稳定性研究

目的对长链脂肪乳注射液及中／长链脂肪乳注射液,分别配制成各种全合一(All-in-One)营养混合液,进行脂肪乳剂乳粒稳定性的对比研究。     

Effects of pH, temperature, concentration, and time on particle counts in lipid-containing total parenteral nutrition admixtures

It has been standard practice in the United States to separate lipid emulsion from the other components of total parenteral nutrition (TPN) due to the reported instability of admixed intravenous lipid emulsions. Some clinicians, however, have combined all TPN components into one container and administered these admixtures to patients without apparent difficulties. Infusion of all nutrients from one container has many advantages. In this study standard and concentrated admixtures were aseptically prepared using generally accepted guidelines of the nutritional requirements for a 70-kg patient. Treatments of standard and concentrated admixtures consisted of: storing at 4 degrees C without adjusting the pH; increasing the pH to 6.6 and storing at 4 degrees C; increasing the pH to 6.6 and storing at room temperature. Samples were monitored for 3 weeks by means of Coulter Counter analysis, pH determinations, and visual observations. The pH of the admixtures did not change over 3 weeks. Mean counts of particles with sizes between 1.6 and 25.4 mu increased over time for each treatment group. Within treatments, concentrated admixtures had significantly greater particle counts than the corresponding standard admixtures. Within the standard and within the concentrated admixtures, the particle counts were significantly greater for group one than for group three. Particle counts in group two tended to lie between the values of group one and three. Visual signs of emulsion deterioration were greatest in those admixtures in which the pH was not adjusted and occurred earlier in concentrated admixtures.     

Dizziness, tiredness and the risk of a stroke

In a recent study, Bos et al. (JAMA 2007) showed that patients with nonfocal transient neurological attacks (TNA) have a higher risk of major vascular disease, comparable to patients with focal TNAs. This may prompt GPs to take a more active approach when dealing with patients experiencing short-lasting attacks of dizziness, paraesthesia and weakness. However, the category of nonfocal TNAs in the abovementioned study was very broad, and subgroup analysis for specific symptoms was not possible. Moreover, a third of nonfocal TNAs consisted of loss of consciousness or decreased consciousness, which might be responsible for the heightened risk of cerebrovascular accident. Also, a quarter of patients with nonfocal TNA had not presented their symptoms to a physician and reported the symptoms during a follow-up meeting, leaving room for recall bias. Since symptoms like dizziness are very frequent among elderly patients and nonfocal TNAs are difficult to recognize, both physicians and education campaigns should be careful not to arouse anxiety without good reason.     

Clinical use of total nutritional admixtures

The administration of a single mixture of the components of total parenteral nutrition (TPN) constitutes total nutritional admixture (TNA), the safety and efficacy of which in a variety of clinical settings have been confirmed by controlled trials. According to the nitrogen balance and stable isotope methods, TNA is as efficacious as the old system of three bottles with piggyback intravenous fat emulsion in maintaining body nitrogen mass, visceral protein, and liver function. Also, serum concentrations of electrolytes, trace elements, and vitamins can be maintained adequately using the TNA system. The other advantages are the timesaving to the nursing staff, with its hidden savings in cost; the avoidance of a peripheral catheter solely for the infusion of lipid emulsion in addition to the central catheter for TPN in hospitalized patients; and the facility of use in home nutrition programs. The ease of home use has resulted in a greater degree of patient compliance; thus patients receive a mixed-fuel system while avoiding the hazards of a piggyback infusion, with all its potential complications. Among the perceived disadvantages of TNA are a supposed higher frequency of catheter-related sepsis, a view based on in vitro studies that is not borne out by in vivo studies; catheter occlusion by precipitation of calcium salts; and enhanced ability to clear fat and thus fat tolerance with continuous infusion of lipids. Numerous studies have shown that these concerns are unwarranted.     

Emulsion stability in a total nutrient admixture for total parenteral nutrition.

A total parenteral nutrition solution containing lipid was tested up to 28 days at 4 degrees C followed by an additional 2 days at 22 degrees C (room temperature) for stability of the emulsion. The total nutrient admixture (TNA) contained 1000 ml 10% FreAmine, 1000 ml 50% dextrose, 500 ml 10% Soyacal, electrolytes, vitamins and trace elements. Stability was determined by direct observation, light and electron microscopy, Coulter counter, pH, osmolality, and fatty acid profile. Samples were tested when fresh at 0 hours, after 2 days at 22 degrees C, 14 days at 4 degrees followed by 2 days at 22 degrees C, and 28 days at 4 degrees C followed by 1 and 2 days at 22 degrees C. Light microscopy measured particles greater than 2 microns in diameter; 99% of these particles were less than 6 microns, with no increase with time. Electron microscopy found that lipid particle size increased slightly up to 30 days, at which time the mean diameter was 0.36 +/- 0.01 micron. Coulter counter studies found that lipid droplet diameter increased while at 22 degrees C; however, on day 30, 99% of the particles were less than 1.97 microns. Mean pH and osmolality were 6.35 +/- 0.04 and 1880 +/- 14.5 mOsm/kg, respectively, with no change over time. Analysis of fatty acids by gas chromatography showed that fatty acid profiles and amounts of triglyceride, phospholipid and total lipid did not change. Thus, the emulsion in the TNA was stable for 28 days refrigeration, followed by 2 days at room temperature.     

Stability of MCT/LCT‐Based Total Nutrient Admixtures for Neonatal Use Over 30 Hours at Room Temperature

Background: United States Pharmacopeial Chapter <729> places a limit on the percentage of large fat globules >5 µm, expressed as a PFAT5 of <0.05% for all native lipid emulsions. Some adult total nutrient admixtures (TNAs) have also remained below this limit for up to 48 hours. In 2003, medium‐chain/long‐chain triglyceride (MCT/LCT)–based neonatal TNAs with between 2% and 3% amino acid (AA) concentrations were shown to be similarly stable by the PFAT5 parameter. Stability assessment of neonatal TNAs with AA <2% or ≥3% were tested. Methods: Eight neonatal TNAs with various combinations of AA (1%, 1.5%, 3%, and 4%), glucose (G; 5% and 10%), and MCT/LCT (ML; 2% and 4%) and standard concentrations of additives were tested in triplicate (n = 24) over 30 hours (immediately after mixing, then at 6, 24, and 30 hours) at 25°C ± 2°C. PFAT5 determinations for all 24 formulations were made in duplicate, immediately after mixing, and then at 6, 24, and 30 hours later. Mean droplet size (MDS) and pH were assessed at the outset and end of the study. Results: The differences in the PFAT5 levels were significant (P < .001) by a 2‐way analysis of variance based on formula and time as the independent variables. The TNAs with 1% and 1.5% AA with all Gs and MLs (group 1, n = 12) had PFAT5 levels >0.05% (up to 0.50%) in most samples (68 of 96 samples, or 71% of cases) in the study, whereas in the same TNAs, but made with 3% and 4% AA (group 2, n = 12), 100% of samples (all 96 cases) had PFAT5 levels <0.05% (up to 0.04%), and this difference was significant (P < .001). Pairwise comparisons between groups based on overall values of PFAT5, MDS, and pH showed significant differences between groups for all variables. Conclusions: For neonatal TNAs, AA level is the most sensitive determinant of stability, and the PFAT5 parameter is the most sensitive indicator of stability.     

Stabilité galénique de mélanges commercialisés de nutrition parentérale en présence de médicaments. (ii) : médicaments perfusés en Y

The aim of the study was to assess compatibility of 7 commonly used parenteral drugs with 3 commercialized total parenteral admixtures (Kabimix^® 1200, Kabiven^® 1600 and Clinomel^® N7-1000) during simulated Y-site infusion. Parenteral drug (acyclovir, amikacin, heparin, methylprednisolone, ondansetron, ranitidine and vancomycin) were simulated infused during 60 min. Samples were collected at T0 (total parenteral nutrition only), T30min and T60min (simulated Y-site infusion), and T75min (back to parenteral admixtures without drugs). Stability assessment included particle-size analysis, zeta potential measurement, pH determination and visual inspection. Precipitation of acyclovir was found. It depends on acyclovir concentration and on the total parenteral nutrition flow rate. Only maximal flow rate of the parenteral admixture and high drug concentration resulted in acyclovir precipitation. Moreover, precipitation led to a change in particle-size distribution with 3 to 9% of particles greater than 5 μm. The other drugs tested were physically compatible during Y-site infusion with the parenteral admixtures. However, amikacin caused a dramatic increase of the zeta potential which came near the critical emulsion stability zone. This effect must be taken into account in case of parenteral admixtures with initial zeta potential near the critical zone. No difference was found between the 3 commercialized total parenteral admixtures.     

Compatibility of medications with 3-in-1 parenteral nutrition admixtures

BACKGROUND: The absence of drug compatibility information with 3-in-1 parenteral nutrition admixtures has been problematic. The purpose of this project was to evaluate the physical compatibility of 106 selected drugs during simulated Y-site injection into nine different 3-in-1 parenteral nutrition admixture formulations. METHODS: Four-milliliter samples of each of the representative 3-in-1 parenteral nutrition admixture formulations were combined in a 1:1 ratio with 4-mL samples of each of 106 drugs, including supportive care drugs, anti-infectives, and antineoplastic drugs. Six replicate samples of each combination were prepared. Two samples were evaluated initially after mixing, two more after 1 hour, and the last two after 4 hours at 23 degrees C. At each test interval, the samples were subjected to centrifugation, causing the fat to rise to the top. The top fat layer and most of the aqueous phase were removed, and the remaining liquid was diluted with about 7 mL of particle-free, high-performance liquid chromatography-grade water to facilitate observation of any particulates that might have formed. Visual examinations were performed in normal diffuse fluorescent laboratory light and under high-intensity, monodirectional light. RESULTS: Most of the drugs tested were physically compatible with the 3-in-1 parenteral nutrition admixtures for 4 hours at 23 degrees C. However, 23 drugs exhibited various incompatibilities with one or more of the parenteral nutrition admixtures. Six drugs resulted in the formation of precipitate with some or all of the admixtures. Seventeen drugs caused disruption of the emulsion, usually with oiling out. CONCLUSIONS: Most of the test drugs were physically compatible with the nine representative 3-in-1 parenteral nutrition admixtures. However, the 23 drugs that resulted in incompatibilities should not be administered simultaneously with the incompatible parenteral nutrition admixtures via a Y injection site.     

Total nutrient admixture: a review

The TNA system of nutritional support has become very popular and offers some unique advantages over the traditional method of administering TPN to hospitalized and home patients. However, these advantages as outlined in this review, must be carefully weighed against potential disadvantages before the TNA system is employed as a nutritional support modality. It should also be noted that the stability of TNA systems is not well established since many stability studies do not provide specific information regarding formulations tested. In addition, many studies do not utilize methods to determine the entire spectrum of particle size and distribution. Droplet size in TNA systems attain a diameter several times larger than the 0.2 to 0.4 micron of manufacturer's lipid emulsions and naturally occurring chylomicrons. Although the administration of the TNA system has not been associated with any acute toxicity, the long-term consequences of infusing droplets larger than 0.4 micron is not definitely known. In addition, the biological implications of using the TNA system need to be elucidated. Subtle differences in the properties of the lipid emulsion can affect the way it is metabolized by the body. Wretlind has mentioned that two apparently similar soybean oil emulsions, Intralipid, and Lipofundin are handled differently by the body. Minor differences in the phospholipid layer of the droplets were postulated as a cause. Certainly the nature of the emulsifying layer of phospholipid on TNA system droplets is modified and therefore may be metabolized differently. The recent report of enhanced growth of microorganisms in TNA systems is also worrisome.(ABSTRACT TRUNCATED AT 250 WORDS)     

不同葡萄糖浓度全合一营养液体外稳定性评估

目的 评估不同时间点添加不同葡萄糖浓度全合一营养液的稳定性,为提高临床应用的安全性提供可靠依据.方法 根据临床应用情况,设计5组不同配方静脉营养液,其中葡萄糖终浓度分别为5％、10％、15％、20％和25％,其他营养素浓度每组相同.配制后的营养液于室温下（25±2）℃储存,分别在0、12、24、48、72 h时观察营养液外观变化,应用扫描电镜测量脂肪颗粒大小,并行营养液渗透浓度和pH值测定.结果 （1）肉眼观察各组营养液配制后0、12、24、48、72 h无颜色变化,未观察到沉淀、分层现象.（2）每组全合一营养液在不同时间点脂肪颗粒平均粒径值差异无统计学意义（F组内=1.255,P=0.324; F组间 =0.025,P=0.998; F交互=1.005,P=0.489）.72 h内,各组脂肪颗粒平均直径均＜0.5 μm,各组均未见到直径＞5.0 μm的脂肪颗粒.（3） 72 h内,所有营养液pH值波动于6.08 ±0.00～6.37±0.01之间.不同时间点5组营养液间pH值比较差异有统计学意义（F组内=3 452.846,P=0.000; F组间=4 655.250,P=0.000; F交互=1.952,P=0.079）.（4） 72 h内,所有营养液平均渗透浓度波动于（609.3±2.3）～（1 625.2±3.5） mOsm/L之间.不同时间点5组营养液间平均渗透浓度比较差异有统计学意义（F组内=176 195.911,P=0.000; F组间=14.732,P=0.006; F交互 =1.203,P=0.343）.结论 全合一营养液中葡萄糖终浓度为5％ ～ 15％时,脂肪颗粒、pH值和渗透压均在安全范围内.     

Stability of parenteral nutrition admixtures containing organic phosphates

The use of organic phosphates to avoid calcium phosphate precipitation in parenteral nutrition mixtures has been proposed. The purpose of this study was to evaluate the stability of total parenteral nutrition admixtures containing glucose-1-phosphate or glycerol phosphate as the phosphate source over 3 days. Three parenteral nutrition admixtures, each containing glucose-1-phosphate (30.0 mmol), glycerol phosphate (31.4 mmol) or inorganic phosphate (30.0 mmol), and their corresponding aqueous phases were prepared in 3-L ethylene vinyl acetate plastic bags and infusion bottles, and stored at 5 +/- 1 degrees C or 22 +/- 3 degrees C without light protection. Physical stability analysis and sampling for chemical analysis was performed at 0, 24, 48 and 72 h. Aqueous phases were subjected to physical stability analysis, including pH measurement, visual inspection and nephelometry. Admixtures were subjected to physical stability analysis consisting of pH measurement, and evaluation of emulsion stability by visual inspection, degree of creaming, phase contrast microscopy, zone sensing technique and photon correlation spectroscopy. Chemical analyses of amino-acids, dextrose, triglycerides, phospholipids, Na, K, Cl, Mg, Ca, glucose-1-phosphate, glycerolphosphate and inorganic phosphate were performed. No precipitation was detected in any of the aqueous phases. Admixtures remained acceptable with respect to visual and microscopic appearance, mean droplet diameter and droplet size distribution. All nutrient concentrations assayed in the three admixtures remained constant over the study period. Total parenteral nutrition admixtures for adult patients containing glucose-1-phosphate or glycerolphosphate are physically and chemically stable for 3 days when stored under refrigeration or controlled room temperature without light protection.     

Effect of phototherapy light, sodium bisulfite, and pH on vitamin stability in total parenteral nutrition admixtures

The three sections of this study extend previous research into losses of vitamins A, C, E, thiamin, riboflavin, and folic acid from total parenteral nutrition (TPN) admixtures. First, phototherapy light on TPN admixtures containing one of four amino acid solutions was studied. Experimental conditions included presence or absence of Intralipid iv fat emulsion, plastic bag or glass bottle storage container, and storage time of up to 48 hrs. The second phase studied stability of the same vitamins (except vitamin E) for 48 hrs in admixtures containing the amino acid solution which has no bisulfite, in glass bottles; with or without Intralipid; and with added sodium bisulfite (final concentrations of 0, 1, 2, 3, 4, 5 and 10 mEq/liter). Third, vitamin C and thiamin levels were measured in admixtures containing the amino acid solution with no bisulfite, without Intralipid, stored in glass bottles with various bisulfite concentrations (0, 1, 2, or 3 mEq/liter) and three pH levels (5.5, 6.5, and 6.75 pH). Exposure of TPN admixtures to phototherapy light caused losses of vitamins A, C, and riboflavin. Intralipid inclusion significantly reduced losses of vitamin A and riboflavin, but did not appear to affect vitamin C levels. The smallest vitamin C losses were noted in admixtures containing amino acid solutions A or B. Phototherapy light did not affect thiamin levels. Bisulfite had no affect on vitamin C, riboflavin, or folic acid levels. Vitamin A levels were maintained with bisulfite concentrations less than 3 mEq/liter. At 3 mEq/liter bisulfite, admixtures with Intralipid showed 50% loss of vitamin A.(ABSTRACT TRUNCATED AT 250 WORDS)