Impact of the COVID-19 pandemic: Community and hospital shared pharmaceutical care model. Satisfaction and acceptability of patients with HIV infection on antiretroviral treatment.

OBJECTIVE: The health crisis due to the COVID-19 pandemic is a challenge in the dispensing of outpatient hospital medication (OHM). Models of Antiretroviral Therapy (ART) based on community pharmacy support (ARTCP) have proven to be successful. The aim was to evaluate the degree of satisfaction, acceptability and limitations of the implementation of ARTCP, in the context of a pandemic, in our environment. METHODS: Descriptive cross-sectional study carried out in a Barcelona hospital, during the months of July-November 2020. A telephone survey was carried out via a questionnaire on the quality dimensions of the model (degree of satisfaction, acceptability) and associated inconveniences. Data collected: demographics, antiretroviral treatment (ART), concomitant medication, drug interactions (DDIs), CD4 lymphocyte count and plasma viraemia. Data analysis included descriptive statistics. RESULTS: A total of 533 (78.0%) HIV patients receiving ART were included. 71.9% (383/533) of these patients were very satisfied and 76.2% preferred attending the community pharmacy rather than the hospital. The mean satisfaction rating was 9.3 (DS: 1.4). The benefits reported were: 1) proximity to home (406: 76.1%); 2) lower risk of contagion of COVID-19 (318: 59.7%); 3) shorter waiting time (201: 37.1%); 4) time flexibility (104: 19.5%); 5) reduction of financial expenses (35: 6.57%). A total of 11 (2%) patients reported no benefit. Only 22.9% reported disadvantages associated with ARTCP: 1) lack of privacy (65: 12.2%); 2) lack of coordinationorganization (57: 10.7%). CONCLUSIONS: The COVID-19 pandemic has had an impact on the provision of pharmaceutical care for HIV patients. The ARTPC model has proved efficient, with patients reporting a high degree of satisfaction.

The optical response of artificially twisted MoS[Formula: see text] bilayers.

Two-dimensional layered materials offer the possibility to create artificial vertically stacked structures possessing an additional degree of freedom-the interlayer twist. We present a comprehensive optical study of artificially stacked bilayers (BLs) MoS[Formula: see text] encapsulated in hexagonal BN with interlayer twist angle ranging from 0[Formula: see text] to 60[Formula: see text] using Raman scattering and photoluminescence spectroscopies. It is found that the strength of the interlayer coupling in the studied BLs can be estimated using the energy dependence of indirect emission versus the A[Formula: see text]-E[Formula: see text] energy separation. Due to the hybridization of electronic states in the valence band, the emission line related to the interlayer exciton is apparent in both the natural (2H) and artificial (62[Formula: see text]) MoS[Formula: see text] BLs, while it is absent in the structures with other twist angles. The interlayer coupling energy is estimated to be of about 50 meV. The effect of temperature on energies and intensities of the direct and indirect emission lines in MoS[Formula: see text] BLs is also quantified.

Resonance and antiresonance in Raman scattering in GaSe and InSe crystals.

The temperature effect on the Raman scattering efficiency is investigated in [Formula: see text]-GaSe and [Formula: see text]-InSe crystals. We found that varying the temperature over a broad range from 5 to 350 K permits to achieve both the resonant conditions and the antiresonance behaviour in Raman scattering of the studied materials. The resonant conditions of Raman scattering are observed at about 270 K under the 1.96 eV excitation for GaSe due to the energy proximity of the optical band gap. In the case of InSe, the resonant Raman spectra are apparent at about 50 and 270 K under correspondingly the 2.41 eV and 2.54 eV excitations as a result of the energy proximity of the so-called B transition. Interestingly, the observed resonances for both materials are followed by an antiresonance behaviour noticeable at higher temperatures than the detected resonances. The significant variations of phonon-modes intensities can be explained in terms of electron-phonon coupling and quantum interference of contributions from different points of the Brillouin zone.

Neutral and charged dark excitons in monolayer WS2.

Low temperature and polarization resolved magneto-photoluminescence experiments are used to investigate the properties of dark excitons and dark trions in a monolayer of WS2 encapsulated in hexagonal BN (hBN). We find that this system is an n-type doped semiconductor and that dark trions dominate the emission spectrum. In line with previous studies on WSe2, we identify the Coulomb exchange interaction coupled neutral dark and grey excitons through their polarization properties, while an analogous effect is not observed for dark trions. Applying the magnetic field in both perpendicular and parallel configurations with respect to the monolayer plane, we determine the g-factor of dark trions to be g ∼ -8.6. Their decay rate is close to 0.5 ns, more than 2 orders of magnitude longer than that of bright excitons.

Measurement of the spin-forbidden dark excitons in MoS2 and MoSe2 monolayers.

Excitons with binding energies of a few hundreds of meV control the optical properties of transition metal dichalcogenide monolayers. Knowledge of the fine structure of these excitons is therefore essential to understand the optoelectronic properties of these 2D materials. Here we measure the exciton fine structure of MoS2 and MoSe2 monolayers encapsulated in boron nitride by magneto-photoluminescence spectroscopy in magnetic fields up to 30 T. The experiments performed in transverse magnetic field reveal a brightening of the spin-forbidden dark excitons in MoS2 monolayer: we find that the dark excitons appear at 14 meV below the bright ones. Measurements performed in tilted magnetic field provide a conceivable description of the neutral exciton fine structure. The experimental results are in agreement with a model taking into account the effect of the exchange interaction on both the bright and dark exciton states as well as the interaction with the magnetic field.

The effect of metallic substrates on the optical properties of monolayer MoSe2.

Atomically thin materials, like semiconducting transition metal dichalcogenides (S-TMDs), are highly sensitive to the environment. This opens up an opportunity to externally control their properties by changing their surroundings. Photoluminescence and reflectance contrast techniques are employed to investigate the effect of metallic substrates on optical properties of MoSe2 monolayer (ML). The optical spectra of MoSe2 MLs deposited on Pt, Au, Mo and Zr have distinctive metal-related lineshapes. In particular, a substantial variation in the intensity ratio and the energy separation between a negative trion and a neutral exciton is observed. It is shown that using metals as substrates affects the doping of S-TMD MLs. The explanation of the effect involves the Schottky barrier formation at the interface between the MoSe2 ML and the metallic substrates. The alignment of energy levels at the metal/semiconductor junction allows for the transfer of charge carriers between them. We argue that a proper selection of metallic substrates can be a way to inject appropriate types of carriers into the respective bands of S-TMDs.

Temperature dependence of photoluminescence lifetime of atomically-thin WSe2 layer.

At cryogenic temperatures, the photoluminescence (PL) spectrum of monolayer WSe2 features a number of lines related to the recombination of so-called localized excitons (LEs). The intensity of these lines strongly decreases with increasing temperature. In order to understand the mechanism behind this phenomenon we carried out a time-resolved experiment, which revealed a similar trend in the PL decay time. Our results identify the opening of additional non-radiative relaxation channels as a primary cause of the observed temperature quenching of the LEs' PL.

Energy Spectrum of Two-Dimensional Excitons in a Nonuniform Dielectric Medium.

We demonstrate that, in monolayers (MLs) of semiconducting transition metal dichalcogenides, the s-type Rydberg series of excitonic states follows a simple energy ladder: ε_{n}=-Ry^{*}/(n+δ)^{2}, n=1,2,…, in which Ry^{*} is very close to the Rydberg energy scaled by the dielectric constant of the medium surrounding the ML and by the reduced effective electron-hole mass, whereas the ML polarizability is accounted for only by δ. This is justified by the analysis of experimental data on excitonic resonances, as extracted from magneto-optical measurements of a high-quality WSe_{2} ML encapsulated in hexagonal boron nitride (hBN), and well reproduced with an analytically solvable Schrödinger equation when approximating the electron-hole potential in the form of a modified Kratzer potential. Applying our convention to other MoSe_{2}, WS_{2}, MoS_{2} MLs encapsulated in hBN, we estimate an apparent magnitude of δ for each of the studied structures. Intriguingly, δ is found to be close to zero for WSe_{2} as well as for MoS_{2} monolayers, what implies that the energy ladder of excitonic states in these two-dimensional structures resembles that of Rydberg states of a three-dimensional hydrogen atom.

Probing and Manipulating Valley Coherence of Dark Excitons in Monolayer WSe_{2}.

Monolayers of semiconducting transition metal dichalcogenides are two-dimensional direct-gap systems which host tightly bound excitons with an internal degree of freedom corresponding to the valley of the constituting carriers. Strong spin-orbit interaction and the resulting ordering of the spin-split subbands in the valence and conduction bands makes the lowest-lying excitons in WX_{2} (X being S or Se) spin forbidden and optically dark. With polarization-resolved photoluminescence experiments performed on a WSe_{2} monolayer encapsulated in a hexagonal boron nitride, we show how the intrinsic exchange interaction in combination with the applied in-plane and/or out-of-plane magnetic fields enables one to probe and manipulate the valley degree of freedom of the dark excitons.

Upconverted electroluminescence via Auger scattering of interlayer excitons in van der Waals heterostructures.

The intriguing physics of carrier-carrier interactions, which likewise affect the operation of light emitting devices, stimulate the research on semiconductor structures at high densities of excited carriers, a limit reachable at large pumping rates or in systems with long-lived electron-hole pairs. By electrically injecting carriers into WSe2/MoS2 type-II heterostructures which are indirect in real and k-space, we establish a large population of typical optically silent interlayer excitons. Here, we reveal their emission spectra and show that the emission energy is tunable by an applied electric field. When the population is further increased by suppressing the radiative recombination rate with the introduction of an hBN spacer between WSe2 and MoS2, Auger-type and exciton-exciton annihilation processes become important. These processes are traced by the observation of an up-converted emission demonstrating that excitons gaining energy in non-radiative Auger processes can be recovered and recombine radiatively.

Raman scattering from the bulk inactive out-of-plane [Formula: see text] mode in few-layer MoTe2.

We report a study of Raman scattering in few-layer MoTe2 focused on high-frequency out-of-plane vibrational modes near 291 cm-1 which are associated with the bulk-inactive [Formula: see text] mode. Our temperature-dependent measurements reveal a double peak structure of the feature related to these modes in the Raman scattering spectra of 4- and 5-layer MoTe2. In accordance with literature data, the doublet's lower- and higher-energy components are ascribed to the Raman-active A1g/[Formula: see text] vibrations involving, respectively, only the inner and surface layers. We demonstrate a strong enhancement of the inner mode's intensity at low temperature for 1.91 eV and 1.96 eV laser light excitation which suggests a resonant character of the Raman scattering processes probed under such conditions. A resonance of the laser light with a singularity of the electronic density of states at the M point of the MoTe2 Brillouin zone is proposed to be responsible for the observed effects.

Singlet and triplet trions in WS2 monolayer encapsulated in hexagonal boron nitride.

Embedding a WS2 monolayer in flakes of hexagonal boron nitride allowed us to resolve and study the photoluminescence response due to both singlet and triplet states of negatively charged excitons (trions) in this atomically thin semiconductor. The energy separation between the singlet and triplet states has been found to be relatively small reflecting rather weak effects of the electron-electron exchange interaction for the trion triplet in a WS2 monolayer, which involves two electrons with the same spin but from different valleys. Polarization-resolved experiments demonstrate that the helicity of the excitation light is better preserved in the emission spectrum of the triplet trion than in that of the singlet trion. Finally, the singlet (intravalley) trions are found to be observable even at ambient conditions whereas the emission due to the triplet (intervalley) trions is only efficient at low temperatures.

The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals.

The electronic band structure of van der Waals (vdW) layered crystals has properties that depend on the composition, thickness and stacking of the component layers. Here we use density functional theory and high field magneto-optics to investigate the metal chalcogenide InSe, a recent addition to the family of vdW layered crystals, which transforms from a direct to an indirect band gap semiconductor as the number of layers is reduced. We investigate this direct-to-indirect bandgap crossover, demonstrate a highly tuneable optical response from the near infrared to the visible spectrum with decreasing layer thickness down to 2 layers, and report quantum dot-like optical emissions distributed over a wide range of energy. Our analysis also indicates that electron and exciton effective masses are weakly dependent on the layer thickness and are significantly smaller than in other vdW crystals. These properties are unprecedented within the large family of vdW crystals and demonstrate the potential of InSe for electronic and photonic technologies.

The excited spin-triplet state of a charged exciton in quantum dots.

We report on spectroscopic studies of resonances related to ladder of states of a charged exciton in single GaAlAs/AlAs quantum dot structures. Polarization-resolved photoluminescence, photoluminescence excitation and photon-correlation measurements were performed at low (T = 4.2 K) temperature also in magnetic field applied in Faraday configuration. The investigated resonances are assigned to three different configurations of a positively charged exciton. Together with a singlet ground state and a conventional triplet state (involving an electron from the ground state electronic s-shell), an excited triplet state, which involved an electron from the excited electronic p-shell was identified in single dots. The appearance of an emission line related to the latter complex is due to a partially suppressed electron relaxation in the investigated dots. An analysis of this emission line allows us to scrupulously determine properties of the excited triplet state and compare them with those of the conventional triplet state. Both triplets exhibit similar patterns of anisotropic fine structure and Zeeman splitting, however their amplitudes significantly differ for those two states. Presented results emphasize the role of the symmetry of the electronic state on the properties of the triplet states of two holes + electron excitonic complex.

Liver function test alterations associated with parenteral nutrition in hospitalized adult patients; incidence and risk factors / Alteraciones de los parámetros hepáticos asociados con la administración de nutrición parenteral en pacientes adultos hospitalizados; incidencia y factores de riesgo

Background: Parenteral nutrition-associated liver dysfunction can be progressive and irreversible, particularly in children and patients with long-term treatment. This study has assessed the incidence of abnormal liver function tests in hospitalized adults during short term parenteral nutrition (PN) and has investigated risk factors for developing alterations of each parameter. Methods: A prospective cohort study of parenteral nutrition treated patients with preserved liver function at baseline. Variables examined included nutritional and clinical data and laboratory parameters. Determinations were performed before starting PN and weekly until liver function test alteration was observed. Risk factors were investigated by four stepwise forward logistical regressions. Results: Eighty patients were included, 57.5% had liver function test alterations. PN mean duration was 15.9 (8-54) days. Mean days with PN and additional enteral/ oral nutrition were 1.5 (0-20). The following associations were found: gamma-glutamyl-transferase increased with soybean lipid intake and absolute diet; alkaline phosphatase increased with septic shock; alanine transaminase increased with septic shock, hyperglycemia and elevated creatinine; total bilirubin increased with septic shock, absolute diet, low prealbumin and glucose, and high creatinine. Conclusions: The incidence of altered liver function tests is high in adult hospitalized patients treated with short-term PN. However, the effect of nutritional factors in this alteration is low. Oral/enteral nutrition and reduction of soybean lipid supply can reduce increases in some liver function tests such as gamma-glutamyl-transferase and total bilirubin. The high association between all liver function tests and clinical systemic-hypermetabolic variables suggest the importance of specific nutritional strategies for this condition (AU)

Introducción: La alteración hepática asociada a la nutrición parenteral (NP) puede ser progresiva e irreversible particularmente en niños y en tratamientos de larga duración. El objetivo de este estudio es establecer la incidencia de las alteraciones de los parámetros hepáticos en pacientes adultos hospitalizados en tratamiento con NP y estudiar los factores de riesgo asociados al desarrollo de las alteraciones de cada uno de los parámetros hepáticos. Métodos: Estudio prospectivo de cohortes de los pacientes tratados con NP con función hepática normal al inicio del tratamiento. Se estudiaron parámetros clínicos, nutricionales y analíticos. Las determinaciones se hicieron antes de iniciar la nutrición y semanalmente hasta que se detectó la alteración de algún parámetro hepático. Los factores de riesgo asociados a la alteración hepática se estudiaron con 4 regresiones logísticas. Resultados: Se incluyeron 80 pacientes y 57,5% mostraron alteraciones hepáticas. La media de duración de la NP fue 15,9 días (8-54) y la media de días con nutrición enteral u oral concomitantes fue de 1,5 (0-20). Se encontraron las siguientes asociaciones: la gamma-glutamil-transferasa aumentaba con la cantidad de lípidos de soja administrados y los días en dieta absoluta; la fosfatasa alcalina con el shock séptico, la alanina-aminotransferasa con el shock séptico, la hiperglucemia y los valores elevados de creatinina; la bilirrubina total con el shock séptico, la dieta absoluta, valores bajos de prealbúmina y glucosa; y valores altos de creatinina. Conclusiones: La incidencia de alteraciones de los parámetros hepáticos es elevada en pacientes adultos hospitalizados tratados con NP, aunque el efecto de los factores nutricionales en esta alteración es bajo. La nutrición oral/enteral y la reducción de los lípidos en forma de soja pueden reducir el aumento de algunos parámetros hepáticos como la gamma-glutamiltransferasa y la bilirrubina total. La gran asociación entre todos los parámetros hepáticos y las variables sistémicas indicadoras de hiper-metabolismo apuntan a la importancia de las estrategias nutricionales específicas en esta situación (AU)

Prevalence and Factors Associated with Vitamin D Deficiency and Hyperparathyroidism in HIV-Infected Patients Treated in Barcelona.

Vitamin D deficiency is an important problem in patients with chronic conditions including those with human immunodeficiency virus (HIV) infection. The aim of this cross-sectional study was to identify the prevalence and factors associated with vitamin D deficiency and hyperparathyroidism in HIV patients attended in Barcelona. Cholecalciferol (25OH vitamin D3) and PTH levels were measured. Vitamin D insufficiency was defined as 25(OH) D < 20 ng/mL and deficiency as <12 ng/mL. Hyperparathyroidism was defined as PTH levels >65 pg/mL. Cases with chronic kidney failure, liver disease, treatments or conditions potentially affecting bone metabolism were excluded. Among the 566 patients included, 56.4% were exposed to tenofovir. Vitamin D insufficiency was found in 71.2% and 39.6% of those had deficiency. PTH was measured in 228 subjects, and 86 of them (37.7%) showed high levels. Adjusted predictors of vitamin D deficiency were nonwhite race and psychiatric comorbidity, while lipoatrophy was a protective factor. Independent risk factors of hyperparathyroidism were vitamin D < 12 ng/mL (OR: 2.14, CI 95%: 1.19-3.82, P: 0.01) and tenofovir exposure (OR: 3.55, CI 95%: 1.62-7.7, P: 0.002). High prevalence of vitamin deficiency and hyperparathyroidism was found in an area with high annual solar exposure.

Deficiency of CB2 cannabinoid receptor in mice improves insulin sensitivity but increases food intake and obesity with age.

AIMS/HYPOTHESIS: The endocannabinoid system has a key role in energy storage and metabolic disorders. The endocannabinoid receptor 2 (CB2R), which was first detected in immune cells, is present in the main peripheral organs responsible for metabolic control. During obesity, CB2R is involved in the development of adipose tissue inflammation and fatty liver. We examined the long-term effects of CB2R deficiency in glucose metabolism. METHODS: Mice deficient in CB2R (Cb2 ( -/- ) [also known as Cnr2]) were studied at different ages (2-12 months). Two-month-old Cb2 (-/-) and wild-type mice were treated with a selective CB2R antagonist or fed a high-fat diet. RESULTS: The lack of CB2R in Cb2 (-/-) mice led to greater increases in food intake and body weight with age than in Cb2 (+/+) mice. However, 12-month-old obese Cb2 (-/-) mice did not develop insulin resistance and showed enhanced insulin-stimulated glucose uptake in skeletal muscle. In agreement, adipose tissue hypertrophy was not associated with inflammation. Similarly, treatment of wild-type mice with CB2R antagonist resulted in improved insulin sensitivity. Moreover, when 2-month-old Cb2 (-/-) mice were fed a high-fat diet, reduced body weight gain and normal insulin sensitivity were observed. CONCLUSIONS/INTERPRETATION: These results indicate that the lack of CB2R-mediated responses protected mice from both age-related and diet-induced insulin resistance, suggesting that these receptors may be a potential therapeutic target in obesity and insulin resistance.

Chronically increased glucose uptake by adipose tissue leads to lactate production and improved insulin sensitivity rather than obesity in the mouse.

AIMS/HYPOTHESIS: In adipocytes, triacylglycerol synthesis depends on the formation of glycerol 3-phosphate, which originates either from glucose, through glycolysis, or from lactate, through glyceroneogenesis. However, glucose is traditionally viewed as the main precursor of the glycerol backbone and thus, enhanced glucose uptake would be expected to result in increased triacylglycerol synthesis and contribute to obesity. METHODS: To further explore this issue, we generated a mouse model with chronically increased glucose uptake in adipose tissue by expressing Gck, which encodes the glucokinase enzyme. RESULTS: Here we show that the production of high levels of glucokinase led to increased adipose tissue glucose uptake and lactate production, improved glucose tolerance and higher whole-body and skeletal muscle insulin sensitivity. There was no parallel increase in glycerol 3-phosphate synthesis in vivo, fat accumulation or obesity. Moreover, at high glucose concentrations, in cultured fat cells overproducing glucokinase, glycerol 3-phosphate synthesis from pyruvate decreased, while glyceroneogenesis increased in fat cells overproducing hexokinase II. CONCLUSIONS/INTERPRETATIONS: These findings indicate that the absence of glucokinase inhibition by glucose 6-phosphate probably led to increased glycolysis and blocked glyceroneogenesis in the mouse model. Furthermore, this study suggests that under physiological conditions, when blood glucose increases, glyceroneogenesis may prevail over glycolysis for triacylglycerol formation because of the inhibition of hexokinase II by glucose 6-phosphate. Together these results point to the indirect pathway (glucose to lactate to glycerol 3-phosphate) being key for fat deposition in adipose tissue.

Nutrición parenteral modular: ¿un nuevo concepto? / Modular parenteral nutrition: a new concept?

Introducción: Definimos Nutrición Parenteral Modular (NPM) como las mezclas de nutrición parenteral (NP) obtenidas a partir de la adición de diferentes macronutrientes a preparados estándar (NPE) tanto binarios (aminoácidos y glucosa) como ternarios (aminoácidos, lípidos y glucosa). Objetivos: El objetivo de este estudio es demostrar que utilizando la NPM se pueden ajustar las fórmulas de NP a las necesidades individuales de cada paciente y disminuir la carga de trabajo. Material y métodos: Estudio retrospectivo de casos y controles de las NP preparadas durante el primer semestre de los años 1995, 2000 y 2005. Las NP se subdividen en: estándar (NPE) —dispensadas sin manipular—, individualizadas (NPI) y modulares. Se comparan los protocolos en los diferentes periodos, y para evaluar la carga de trabajo se relaciona el volumen de fluido trasvasado con el volumen total preparado. Se aplican los tests de chi cuadrado y t de Student con significación para p < 0,05. Resultados: En 1995 prácticamente sólo se utilizaban fórmulas individualizadas. En el año 2000 se introdujeron NPE y NPM para las fórmulas de mantenimiento y las de estrés moderado. Finalmente, en el año 2005 se ha incluido el concepto modular para fórmulas de estrés severo y/o inmunomoduladoras. Como consecuencia de estos cambios, en el protocolo se observa una disminución de las NPI debido a la introducción progresiva de las NPM. En 1995 la NPM representaba un 2,6% del total de elaboraciones, aumentando a un 64,7% en el 2000 y a un 74,7% en el 2005. Este hecho se ha traducido en una disminución en el volumen trasvasado a través del sistema volumétrico de elaboración. En 1995 se trasvasó el 87,3% del volumen total, en el 2000 el 34,3% y finalmente en el 2005 pasó a ser sólo de un 20,6% (diferencias estadísticamente significativas entre los tres periodos; p < 0,05). En el año 2005 se elaboraron 543 NPI, de las cuales 169 (31,1%) fueron para pacientes con encafalopatía hepática o con insuficiencia renal aguda no dializados. A las NPM elaboradas durante este mismo periodo, se ha incorporado: glutamina, emulsiones lipídicas de aceite de pescado, lípidos estructurados, lípidos de patrón de oliva, soluciones poliiónicas y micronutrientes específicos. Discusión: La NPM permite adecuar las fórmulas de NP a un amplio abanico de situaciones clínicas, aunque en determinadas patologías siguen siendo imprescindibles las formulaciones individualizadas. La utilización de NPM se traduce en una disminución de fórmulas individualizadas que se refleja en una menor carga de trabajo

Introduction: We may define Modular Parenteral Nutrition (MPN) as parenteral nutrition (PN) mixtures obtained from adding different macronutrients to standard formulations (SPN) both binary (amino acids and glucose) and ternary (amino acids, lipids, and glucose). Objectives: The aim of this study is to demonstrate that PN formulations may be adapted to individual needs of each patient and workload may be reduced by using MPN. Material and methods: Case-control retrospective study of PN prepared during the first semester of the years 1995, 2000, and 2005. PN are categorized in: standard (SPN) —given without manipulation—, individualized (IPN), and modular parenteral nutrition (MPN). The protocols are compared at the different periods, and the volume of transferred fluid is related with total prepared volume in order to calculate the workload. The Chi squared and student’s t tests with a significance level of p < 0.05 are used. Results: In 1995, virtually only individualized formulations were used. In the year 2000, SPN and MPN were introduced as maintenance formulas as well as those for moderate stress. Finally, in the year 2005, the modular concept has been introduced for severe stress and/or immunomodulatory formulas. As a result of these changes, we observe in the protocol a decrease in IPN due to progressive introduction of MPN. In 1995, MPN represented 2.6% of all elaborations, increasing up to 64.7% in 2000, and to 74.7% in 2005. This fact has resulted in a decrease in transferred volume through the volumetric elaboration system. In 1995, 87.3% of the total volume was transferred, in the year 2000 34.3%, and finally in 2005 only 20.6% (the differences between the three periods are statistically significant; p < 0.05). In the year 2005, 543 IPN were elaborated, of which 169 (31.1%) were for patients with liver encephalopathy or non-dialyzed acute renal failure. The following ingredients have been added to MPN during that same period: glutamine, fish oil lipid emulsions lipídicas, structured lipids, olive-pattern lipids, polyionic solutions, and specific micronutrients. Discussion: MPN allows for adapting PN formulas to a wide range of clinical situations, although individualized formulations still are irreplaceable for some pathologies. The use of MPN is associated with a decrease in individualized formulas that reflects in lower workload

[Modular parenteral nutrition: a new concept?]. / Nutrición parenteral modular: un nuevo concepto?

INTRODUCTION: We may define Modular Parenteral Nutrition (MPN) as parenteral nutrition (PN) mixtures obtained from adding different macronutrients to standard formulations (SPN) both binary (amino acids and glucose) and ternary (amino acids, lipids, and glucose). OBJECTIVES: The aim of this study is to demonstrate that PN formulations may be adapted to individual needs of each patient and workload may be reduced by using MPN. MATERIAL AND METHODS: Case-control retrospective study of PN prepared during the first semester of the years 1995, 2000, and 2005. PN are categorized in: standard (SPN) -given without manipulation-, individualized (IPN), and modular parenteral nutrition (MPN). The protocols are compared at the different periods, and the volume of transferred fluid is related with total prepared volume in order to calculate the workload. The Chi squared and student's t tests with a significance level of p < 0.05 are used. RESULTS: In 1995, virtually only individualized formulations were used. In the year 2000, SPN and MPN were introduced as maintenance formulas as well as those for moderate stress. Finally, in the year 2005, the modular concept has been introduced for severe stress and/or immunomodulatory formulas. As a result of these changes, we observe in the protocol a decrease in IPN due to progressive introduction of MPN. In 1995, MPN represented 2.6% of all elaborations, increasing up to 64.7% in 2000, and to 74.7% in 2005. This fact has resulted in a decrease in transferred volume through the volumetric elaboration system. In 1995, 87.3% of the total volume was transferred, in the year 2000 34.3%, and finally in 2005 only 20.6% (the differences between the three periods are statistically significant; p < 0.05). In the year 2005, 543 IPN were elaborated, of which 169 (31.1%) were for patients with liver encephalopathy or non-dialyzed acute renal failure. The following ingredients have been added to MPN during that same period: glutamine, fish oil lipid emulsions lipidicas, structured lipids, olive-pattern lipids, polyionic solutions, and specific micronutrients. DISCUSSION: MPN allows for adapting PN formulas to a wide range of clinical situations, although individualized formulations still are irreplaceable for some pathologies. The use of MPN is associated with a decrease in individualized formulas that reflects in lower workload.