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PubMed1990

Stability of total nutrient admixtures in a dual-chamber flexible container.

The stability of total nutrient admixtures (TNAs) prepared from dextrose and amino acid injections commercially packaged in a dual-chamber container and a safflower-soybean oil fat emulsion was studied. The admixtures studied were divided into two groups. Group 1 admixtures represented 14 combinations of Aminosyn II, dextrose, and Liposyn II. Group 2 admixtures represented 10 combinations of Aminosyn II with Electrolytes, dextrose, and Liposyn II. Amino acid concentrations of 7, 8.5, and 10%, dextrose concentrations of 10, 20, 40, and 50%, and 10 and 20% fat emulsion were used. After the amino acid and dextrose injections were mixed in their original container (Nutrimix, Abbott Laboratories), the fat emulsion was added. One of two combinations of electrolytes and trace metals was then added. Multivitamins were added to each TNA just before 24-hour storage at room temperature (25 +/- 4 degrees C). Admixtures were tested initially and at the conclusion of storage periods of 24 hours at room temperature or nine days at 5 degrees C followed by 24 hours at room temperature. Measurements of pH, emulsion particle size, and weight percent of oil particles larger than 5 microns in diameter (HIAC) were made after visual inspection of each admixture. In selected admixtures, concentrations of individual amino acids and dextrose were determined by chromatographic techniques initially and at the conclusion of storage. The TNAs retained a uniform milk-like appearance throughout both storage periods. The pH values, particle size, HIAC measurements, and amino acid and dextrose concentrations remained essentially unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1987

Stability of total nutrient admixtures using various intravenous fat emulsions.

The stability of four lipid emulsions with amino acids and dextrose in total nutrient admixtures (TNAs) was studied. The admixtures were divided into three groups. In group 1, 24 admixtures representing 20 different combinations of Liposyn II (safflower oil-soybean oil fat emulsion) with various manufacturers' amino acids (FreAmine III, Travasol, Novamine, Nephramine, and RenAmin) were tested. In group 2, 19 TNAs representing 14 combinations containing soybean-oil emulsions (Intralipid, Travamulsion, and Soyacal) and Aminosyn II amino acids were studied. In group 3, 14 TNAs representing 9 combinations containing the above soybean oil emulsions and Aminosyn II with Electrolytes were tested. Both 10% and 20% concentrations of fat emulsion, various amino acid concentrations ranging from 5.4% to 11.4%, and dextrose injections of 10, 20, 40, 50, and 70% were used. The admixtures were compounded in an ethylene vinyl acetate container. The mixing sequence involved transfer of fat emulsion to the empty container, followed by amino acids and dextrose. One of two electrolyte and trace metal profiles was added to each core admixture after compounding. Multivitamins were added just before the 24-hour room-temperature (25 +/- 4 degrees C) storage. Admixtures were tested initially and after one day at room temperature or nine days at 5 degrees C plus one day at room-temperature storage. Measurements of pH, emulsion particle size, osmolality, and zeta potential (electrostatic surface charge of lipid particles) were made after visual inspection of each admixture. In general, the TNAs retained a uniform, milk-like appearance under both storage conditions. The values of pH, zeta potential, particle size, and osmolality remained essentially unchanged throughout the study. Under the conditions of this study, the TNA formulations tested are stable for up to 10 days.

Chemical Phenomena↗
PubMed1985

Osmolality of small-volume intravenous admixtures.

Osmolalities of commonly administered small-volume i.v. admixtures were determined, and use of diluents with lower osmolality to achieve osmolality values less than 400 mOsm/kg was studied. The theoretical osmolality of 218 hypothetical admixtures of various concentrations of 34 injectable drugs in 50- or 100-mL quantities of 5% dextrose injection or 0.9% sodium chloride injection was calculated using sodium chloride equivalents. If the calculated osmolality value was greater than 400 mOsm/kg, an actual admixture was prepared and osmolality and density were measured. To determine how admixtures with osmolality values less than 400 mOsm/kg could be prepared, theoretical osmolality was calculated using 0.45% sodium chloride injection or sterile water for injection as the diluent. The calculated osmolality value was greater than 400 mOsm/kg for 52 (23.9%) of the 218 admixtures tested. Of the 52 measured osmolality values, 47 were within 15% of the calculated value. Calculated osmolality values for all admixtures were less than 400 mOsm/kg when 0.45% sodium chloride injection or sterile water for injection was used as the diluent. Admixture osmolality should be considered when preparing drugs for i.v. injection. For drugs with high osmolalities, 0.45% sodium chloride injection or sterile water for injection may be used as the diluent.

Anti-Bacterial Agents↗
PubMed1979

Compounding times and contamination rates associated with the preparation of intravenous admixtures in three types of plastic containers.

The compounding times and contamination rates associated with the preparation of admixtures in three different plastic i.v. containers of dextrose 5% in water were compared. The time required for a technician to prepare, in a laminar air flow hood by the needle and syringe technique, 120 admixtures in each of three different plastic i.v. containers was measured and recorded by two investigators. The 360 admixtures were tested within one hour of preparation for sterility using an enriched brain heart infusion broth. The total time required to compound the i.v. admixtures varied significantly with container design (p less than 0.01), preparation being fastest with the Accumed container, followed by the LifeCare then the Viaflex containers. The major contributing factors to increased compounding time were (1) removal of outer wrap, (2) swabbing of LifeCare and Viaflex medication ports with isopropyl alcohol pads and (3) freeing of the hangar flap from the Viaflex container. Sterility tests revealed no detectable contamination of any of the admixtures. Container design of plastic i.v. containers did influence the preparation time for admixtures but did not influence admixture sterility.

Drug Combinations↗
PubMed1979

Adventitious contamination of intravenous admixtures during sterility testing.

The extent to which contamination of intravenous fluids measured by inhospital sterility-testing may be due to adventitious contamination (i.e., contamination introduced during the sterility-testing procedure) was studied. All one-liter admixtures prepared during a three-day period in a busy centralized i.v. admixture service were studied. Samples of i.v. admixtures were cultured before and after administration by direct ioculation or by culturing the membrane through which the admixture was filtered. Samples of similarly cultured large-volume parenterals served as controls. Contamination rates for control and admixture samples were not significantly different (p = 0.23). Of 10 control and test (admixture) solutions showing contamination before administration, only one test solution again showed contamination after administration but this was with a different microbe. The results suggest that adventitious contamination during sampling/culturing procedures is a component of, and possibly a dominant factor in, the contamination rates detected by inhospital sterility tests. Combined with infection surveillance, sterility tests may be of value when infections are possibly related to admixture contamination.

Bacteria↗
PubMed1988

Effects of English admixture and geographic distance on anthropometric variation and genetic structure in 19th-century Ireland.

The analysis of anthropometric data often allows investigation of patterns of genetic structure in historical populations. This paper focuses on interpopulational anthropometric variation in seven populations in Ireland using data collected in the 1890s. The seven populations were located within a 120-km range along the west coast of Ireland and include islands and mainland isolates. Two of the populations (the Aran Islands and Inishbofin) have a known history of English admixture in earlier centuries. Ten anthropometric measures (head length, breadth, and height; nose length and breadth; bizygomatic and bigonial breadth; stature; hand length; and forearm length) on 259 adult Irish males were analyzed following age adjustment. Discriminant and canonical variates analysis were used to determine the degree and pattern of among-group variation. Mahalanobis' distance measure, D2, was computed between each pair of populations and compared to distance measures based on geographic distance and English admixture (a binary measure indicating whether either of a pair of populations had historical indications of admixture). In addition, surname frequencies were used to construct distance measures based on random isonymy. Correlations were computed between distance measures, and their probabilities were derived using the Mantel matrix permutation method. English admixture has the greatest effect on anthropometric variation among these populations, followed by geographic distance. The correlation between anthropometric distance and geographic distance is not significant (r = -0.081, P = .590), but the correlation of admixture and anthropometric distance is significant (r = 0.829, P = .047). When the two admixed populations are removed from the analysis the correlation between geographic and anthropometric distance becomes significant (r = 0.718, P = .025). Isonymy distance shows a significant correlation with geographic distance (r = 0.425, P = .046) but not with admixture distance (r = -0.052, P = .524). The fact that anthropometrics show past patterns of gene flow and surnames do not reflects the greater impact of stochastic processes on surnames, along with the continued extinction of surnames. This study shows that 1) anthropometrics can be extremely useful in assessing population structure and history, 2) differential gene flow into populations can have a major impact on local genetic structure, and 3) microevolutionary processes can have different effects on biological characters and surnames.

Adult↗
PubMed2003

Relation of risk of systemic lupus erythematosus to west African admixture in a Caribbean population.

Risk of systemic lupus erythematosus (SLE) is higher in people of west African descent than in Europeans. The objective of this study was to distinguish between genetic and environmental explanations for this ethnic difference by examining the relationship of disease risk to individual admixture (defined as the proportion of the genome that is of west African ancestry); 124 cases of SLE and 219 matched controls resident in Trinidad were studied. Analysis of admixture was restricted to 52 cases and 107 controls who reported no Indian or Chinese ancestry. These individuals were typed with a panel of 26 single-nucleotide polymorphisms and five insertion/deletion polymorphisms chosen to have large allele frequency differentials between west African, European and Native American populations. A Bayesian model for population admixture, individual admixture and locus ancestry was fitted by Markov chain simulation. Mean west African admixture (M) was 0.81 in cases and 0.74 in controls (P=0.01). The risk ratio for SLE associated with unit change in M was estimated as 32.5 with a 95% confidence interval (CI) of 2.0-518. Adjustment for measures of socioeconomic status (household amenities in childhood and years of education) altered this risk ratio only slightly (adjusted risk ratio: 28.4, 95% CI 1.7-485). These results support an additive genetic model for the ethnic difference in risk of SLE between west Africans and Europeans, rather than an environmental explanation or an "overdominant" model in which risk is higher in heterozygous than in homozygous individuals. This conclusion lays a basis for localizing the genes underlying this ethnic difference in risk of SLE by admixture mapping.

Adult↗
PubMed1995

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.

Journal Article↗
PubMed2001

Analysis of all-in-one parenteral nutrition admixtures by liquid chromatography and laser diffraction: study of stability.

All-in-one parenteral nutrition admixtures are complex lipid emulsions (oil/water) which require absolute sterility, stability and no precipitates. Particle diameter must be in the range 0.4--1 microm in order to mime the size of chylomicra. Added vitamins must not degrade during infusion time (24 h). In this study, the physicochemical stability of parenteral nutrition admixtures was tested in the course of time at different storage temperatures. Two liquid chromatographic methods, based on solid phase extraction (SPE), were developed for fat-soluble vitamin determination. Stability studies were carried out on three industrial lipid emulsions and on six compounded all-in-one admixtures. They were stored at three different temperatures: 4 degrees C (storage), 25 degrees C (compounding) and 37 degrees C (infusion); then they were analyzed at starting time and at 24, 48 and 72 h after compounding. Particle diameter was determined by means of Laser Particle Sizer Analysette 22, which uses laser diffraction technique (light scattering -- reverse Fourier optics). Fat-soluble vitamins (retinol palmitate and alpha-, delta-, gamma-tocopherol) were determined in admixtures with a branded vitamin compound called Idroplurivit Liofilizzato. Samples were extracted by SPE on C(18) cartridges, then they were separated by reversed-phase liquid chromatography (LC) and detected by ultraviolet detection (retinol palmitate) and electrochemical detection (tocopherols). Laser diffraction analysis pointed out that particle size did not change in the course of time at the tested temperatures. LC analysis showed that vitamins interact each other and degrade after compounding at different times and storage temperatures; only retinol palmitate is stable at 37 degrees C. Retinol palmitate recovery was 98%, coefficient of variation (CV) 5.4%, detection limit 25 microg/l, limit of quantitation 75 microg/l and there were not interfering substances. Tocopherols average recovery was 99%, CV 3.5%, detection limit 15 ng/l and limit of quantitation 50 ng/l. In conclusion, all-in-one parenteral admixtures were proved to be physically stable under analysis conditions, but degradation of retinol palmitate and tocopherols requires admixtures with vitamins to be infused within 24 h after compounding.

Chromatography, Liquid↗
PubMed2006

Improving the safety of intravenous admixtures: lessons learned from a Pentostam overdose.

CASE STUDY: Weaknesses in the multistep process of admixture preparation and administration resulted in a patient with cutaneous leishmaniasis (CL) receiving a 10-fold intravenous (IV) overdose of Pentostam (sodium stibogluconalte), a rarely used drug. LESSONS LEARNED: A review of this adverse event resulted in five recommendations: (1) Provide staffing continuity among pharmacists and pharmacy technicians preparing and nurses administering the admixture; (2) Take time to ensure thorough and deliberative consideration ofquestions or concerns about admixture preparation; (3) Use due diligence in performing double checks of admixture calculations; (4) Know the drug and seek clarification when appropriate; and (5) Examine label information carefully. PROGRESS UPDATE: Two changes were made to improve patientsafety. First, a form was developed to accompany the preparation of complex IV drugs, including chemoltherapy solutions and nonformulary IV admixtures; the form is consistently used. Second, the pharmacy service developed information sheets for 12 high-risk drugs frequently used in IV admixtures. DISCUSSION: The medical center had processes in place to prevent medication errors, yet an error occurred nonetheless. Weaknesses were identified in staff communication, quality assurance checks, and product labeling. Also, nurses and pharmacists had less than adequate information about new or unusually dosed medications.

Adult↗
PubMed1988

Admixture as a tool for finding linked genes and detecting that difference from allelic association between loci.

Admixture between genetically different populations may produce gametic association between gene loci as a function of the genetic difference between parental populations and the admixture rate. This association decays as a function of time since admixture and the recombination rate between the loci. Admixture between genetically long-separated human populations has been frequent in the centuries since the age of exploration and colonization, resulting in numerous hybrid descendant populations today, as in the Americas. This represents a natural experiment for genetic epidemiology and anthropology, in which to use polymorphic marker loci (e.g., restriction fragment length polymorphisms) and disequilibrium to infer a genetic basis for traits of interest. In this paper we show that substantial disequilibrium remains today under widely applicable situations, which can be detected without requiring inordinately close linkage between trait and marker loci. Very disparate parental allele frequencies produce large disequilibrium, but the sample size needed to detect such levels of disequilibrium can be large due to the skewed haplotype frequency distribution in the admixed population. Such situations, however, provide power to differentiate between disequilibrium due just to population mixing from that due to physical linkage of loci--i.e., to help map the genetic locus of the trait. A gradient of admixture levels between the same parental populations may be used to test genetic models by relating admixture to disequilibrium levels.

Alleles↗
PubMedDate not supplied

Admixture estimates for Churuguara, a Venezuelan town in the State of Falcón.

BACKGROUND: The present Venezuelan population is the admixture product of Amerindians, Europeans and Africans, a process which was not homogeneous over the country. Blood groups, STRs and VNTRs, specifically D1S80, have been used successfully in admixture studies, but few have been made in Venezuela. AIM: This study aims to estimate the admixture components of Churuguara, Venezuela, and to evaluate the genetic relationship of this population with other Venezuelan as well as worldwide populations through principal component analysis and the study of dendrograms based on genetic distances. SUBJECTS AND METHODS: Gene frequencies of blood groups ABO and Rh (only anti D), of STRs VWA, F13A01, FES/FPS and VNTR D1S80 were studied in a sample of 60 individuals born in Churuguara, a Venezuelan town of admixed ancestry in the State of Falc6n. Admixture was estimated with Chakraborty's gene identity method, and Nei's standard genetic distance was used to build two dendrograms with the neighbour-joining approach, one based on the three STRs and the other based only on D1S80. Principal component analyses with the gene frequencies of these markers were also performed. RESULTS: The frequency of allele ABO*O was 0.788, of ABO*A was 0.187 and of RH*D was 0.74. D1S80 showed 16 different alleles with a heterozygosity of 0.880, whilst the three STRs showed only eight different alleles and heterozygosities between 0.733 and 0.797. The estimates of admixture obtained in this analysis were 52.5% for the Spanish parental group, 27.6% for the African and 19.9% for the Amerindian. Comparison of Churuguara with other Latin American populations shows that its African component is not as high as that observed in Colombian Choco, but it is higher than that observed in other samples from Colombia, Chile and Maracaibo (Venezuela). CONCLUSIONS: Results of the admixture analysis are consistent with those obtained with two dendrograms and principal component analyses, suggesting that the strong initial Amerindian component of 500 years ago has been diluted by the continuous flow of European genes, mainly Spanish, to this region.

ABO Blood-Group System↗
PubMed2001

Estimation of admixture proportions: a likelihood-based approach using Markov chain Monte Carlo.

When populations are separated for long periods and then brought into contact for a brief episode in part of their range, this can result in genetic admixture. To analyze this type of event we considered a simple model under which two parental populations (P1 and P2) mix and create a hybrid population (H). After that event, the three populations evolve under pure drift without exchange during T generations. We developed a new method, which allows the simultaneous estimation of the time since the admixture event (scaled by the population size t(i) = T/N(i), where N(i) is the effective population size of population i) and the contribution of one of two parental populations (which we call p1). This method takes into account drift since the admixture event, variation caused by sampling, and uncertainty in the estimation of the ancestral allele frequencies. The method is tested on simulated data sets and then applied to a human data set. We find that (i) for single-locus data, point estimates are poor indicators of the real admixture proportions even when there are many alleles; (ii) biallelic loci provide little information about the admixture proportion and the time since admixture, even for very small amounts of drift, but can be powerful when many loci are used; (iii) the precision of the parameters' estimates increases with sample size n = 50 vs. n = 200 but this effect is larger for the t(i)'s than for p1; and (iv) the increase in precision provided by multiple loci is quite large, even when there is substantial drift (we found, for instance, that it is preferable to use five loci than one locus, even when drift is 100 times larger for the five loci). Our analysis of a previously studied human data set illustrates that the joint estimation of drift and p1 can provide additional insights into the data.

Bayes Theorem↗
PubMed1997

Effect of antihypertensive agents on the arterial partial pressure of oxygen and venous admixture after cardiac surgery.

OBJECTIVE: To determine whether stopping nitroglycerin and sodium nitroprusside (both vasodilators) infusions in hypertensive, postcardiac surgical patients requiring a high FIO2 improves PaO2 and venous admixture. DESIGN: Prospective, clinical trial. SETTING: Intensive care unit in a university-affiliated hospital. PATIENTS: Thirty postcardiac surgical patients who, because of high FIO2 requirements, did not meet the criteria for weaning from mechanical ventilation and who were receiving infusions of nitroglycerin and/or sodium nitroprusside to control blood pressure. INTERVENTIONS: PaO2, venous admixture, and oxygen transport data were determined at baseline using arterial and mixed venous blood gas samples and hemodynamic values from a pulmonary artery catheter. The nitroglycerin and sodium nitroprusside infusions were stopped, and intravenous boluses of labetalol were administered to maintain a target blood pressure. After the vasodilator infusions were stopped, the baseline measurements were repeated to redetermine PaO2, venous admixture, and oxygen transport values. MEASUREMENTS AND MAIN RESULTS: Results included a mean increase in PaO2 from 79.3 +/- 15 torr (10.5 +/- 2.0 kPa) to 118.3 +/- 38 torr (15.7 +/- 5.1 kPa) and a mean decrease in venous admixture from 26.4 +/- 5.8% to 17.6 +/- 5.6% when the vasodilators were stopped. All 30 patients had an increase in PaO2 and a decrease in venous admixture. Because of the improvement in oxygenation, 28 of the 30 patients met the criteria for weaning from mechanical ventilation once nitroglycerin and sodium nitroprusside were stopped or decreased. Labetalol was well tolerated in this group of patients who had preserved ventricular function. CONCLUSIONS: Substituting labetalol for nitroglycerin and sodium nitroprusside improves arterial oxygenation and venous admixture in hypertensive postcardiac surgical patients who require a high FIO2. This change in therapy may allow patients to be weaned from mechanical ventilation sooner.

Aged↗
PubMed2005

On the formula for admixture linkage disequilibrium.

Admixture linkage disequilibrium (ALD), a phenomenon created by gene flow between genetically distinct populations, has for some time been used as a tool in gene mapping. It is therefore important to analyze the pattern of ALD over generations. In this study we explore two models of admixture: the gradual admixture (GA) model, in which admixture occurs at a variable rate in every generation; and the immediate admixture (IA) model, a special case of the GA model, in which admixture occurs in a single generation. In the case of ALD, the well-known formula of linkage disequilibrium (Delta(t)=(1-r)t Delta(0)) is not applicable under these two models. We note the effect of a random mating population (RMP) to the gametic frequencies from the parental population to the offspring population, and provide the correct formula for ALD.

Chromosome Mapping↗
PubMedDate not supplied

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)

Amino Acids↗
PubMedDate not supplied

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.

Amino Acids↗
PubMedDate not supplied

Central line occlusion with three-in-one nutrition admixtures administered at home.

The use of single-container parenteral nutrition admixtures can be cost effective and can simplify home administration. Three-in-one admixtures (dextrose, amino acids, lipid emulsion, and other additives in a single bag) were in use when a marked increase in catheter occlusions was seen in the pediatric home parenteral nutrition population. Insoluble laminar deposits were found in the removed catheters. In all subsequently placed catheters, separate (SPLIT) infusions of lipid and parenteral nutrition solution were used rather than three-in-one admixtures. This was associated with an obvious decrease in catheter occlusions. Catheter life-span was retrospectively determined for 15 catheters of identical size and style that were used in eight patients who had received either infusions of three-in-one admixtures or SPLIT infusions. Life table survival analysis revealed a median survival time of 70 days for the three-in-one group (n = 8) and 290 days for the SPLIT group (n = 7). Survival distributions for the two groups were significantly different (p = .025). During the period of clustered catheter occlusion, the use of three-in-one admixtures that were stored in the home for up to 7 days was associated with a shortened catheter life-span. Occlusion or deposit development was not seen in catheters used for inpatient parenteral nutrition support when admixtures were prepared and infused within 28 hours. Catheter deposits were implicated as sanctuary sites for pathogenic bacteria in two patients. Failure to retrieve and inspect occluded catheters delayed the identification of the deposits.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheterization, Central Venous↗