Hypoxic/ischemic models in newborn piglet: Comparison of constant FiO(2) versus variable FiO(2) delivery

A comparison of a constant (continuous delivery of 4% FiO(2)) and a variable (initial 5% FiO(2) with adjustments to induce low amplitude EEG (LAEEG) and hypotension) hypoxic/ischemic insult was performed to determine which insult was more effective in producing a consistent degree of survivable neuropathological damage in a newborn piglet model of perinatal asphyxia. We also examined which physiological responses contributed to this outcome. Thirty-nine 1-day-old piglets were subjected to either a constant hypoxic/ischemic insult of 30- to 37-min duration or a variable hypoxic/ischemic insult of 30-min low peak amplitude EEG (LAEEG < 5 mu V) including 10 min of low mean arterial blood pressure (MABP < 70% of baseline). Control animals (n = 6) received 21% FiO(2) for the duration of the experiment. At 72 h, the piglets were euthanased, their brains removed and fixed in 4% paraformaldehyde and assessed for hypoxic/ischemic injury by histological analysis. Based on neuropathology scores, piglets were grouped as undamaged or damaged; piglets that did not survive to 72 h were grouped separately as dead. The variable insult resulted in a greater number of piglets with neuropathological damage (undamaged = 12.5%, damaged = 68.75%, dead = 18.75%) while the constant insult resulted in a large proportion of undamaged piglets (undamaged = 50%, damaged = 22.2%, dead = 27.8%). A hypoxic insult varied to maintain peak amplitude EEG < 5 mu V results in a greater number of survivors with a consistent degree of neuropathological damage than a constant hypoxic insult. Physiological variables MABP, LAEEG, pH and arterial base excess were found to be significantly associated with neuropathological outcome. (c) 2006 Elsevier B.V. All rights reserved.

Uroscopic rainbow: modern matula medicine

Visual inspection of a patient's urine has long been used by physicians, with colour recognised as having important clinical implications. In this review the authors will revisit this ancient pastime with relevance to contemporary medical practice.

The effect of caudal block on functional residual capacity and ventilation homogeneity in healthy children

Caudal block results in a motor blockade that can reduce abdominal wall tension. This could interact with the balance between chest wall and lung recoil pressure and tension of the diaphragm, which determines the static resting volume of the lung. On this rationale, we hypothesised that caudal block causes an increase in functional residual capacity and ventilation distribution in anaesthetised children. Fifty-two healthy children (15-30 kg, 3-8 years of age) undergoing elective surgery with general anaesthesia and caudal block were studied and randomly allocated to two groups: caudal block or control. Following induction of anaesthesia, the first measurement was obtained in the supine position (baseline). All children were then turned to the left lateral position and patients in the caudal block group received a caudal block with bupivacaine. No intervention took place in the control group. After 15 nun in the supine position, the second assessment was performed. Functional residual capacity and parameters of ventilation distribution were calculated by a blinded reviewer. Functional residual capacity was similar at baseline in both groups. In the caudal block group, the capacity increased significantly (p < 0.0001) following caudal block, while in the control group, it remained unchanged. In both groups, parameters of ventilation distribution were consistent with the changes in functional residual capacity. Caudal block resulted in a significant increase in functional residual capacity and improvement in ventilation homogeneity in comparison with the control group. This indicates that caudal block might have a beneficial effect on gas exchange in anaesthetised, spontaneously breathing preschool-aged children with healthy lungs.

Solubilisation of drugs within liposomal bilayers:alternatives to cholesterol as a membrane stabilising agent

Objectives The aim of this work was to investigate the effect of cholesterol on the bilayer loading of drugs and their subsequent release and to investigate fatty alcohols as an alternative bilayer stabiliser to cholesterol. Methods The loading and release rates of four low solubility drugs (diazepam, ibuprofen, midazolam and propofol) incorporated within the bilayer of multilamellar liposomes which contained a range of cholesterol (0–33 mol/mol%) or a fatty alcohol (tetradecanol, hexadecanol and octadecanol) were investigated. The molecular packing of these various systems was also investigated in Langmuir monolayer studies. Key findings Loading and release of drugs within the liposome bilayer was shown to be influenced by their cholesterol content: increasing cholesterol content was shown to reduce drug incorporation and inclusion of cholesterol in the bilayer changed the release profile of propofol from zero-order, for phosphatidyl choline only liposomes, to a first-order model when 11 to 33 total molar % of cholesterol was present in the formulation. At higher bilayer concentrations substitution of cholesterol with tetradecanol was shown to have less of a detrimental impact on bilayer drug loading. However, the presence of cholesterol within the liposome bilayer was shown to reduce drug release compared with fatty alcohols. Monolayer studies undertaken showed that effective mean area per molecule for a 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) : cholesterol mixture deviated by 9% from the predicted area compared with 5% with a similar DSPC : tetradecanol mixture. This evidence, combined with cholesterol being a much more bulky structure, indicated that the condensing influence of tetradecanol was less compared with cholesterol, thus supporting the reduced impact of tetradecanol on drug loading and drug retention. Conclusions Liposomes can be effectively formulated using fatty alcohols as an alternative bilayer stabiliser to cholesterol. The general similarities in the characteristics of liposomes containing fatty alcohols or cholesterol suggest a common behavioural influence for both compounds within the bilayer.

Microfluidic-controlled manufacture of liposomes for the solubilisation of a poorly water soluble drug

Besides their well-described use as delivery systems for water-soluble drugs, liposomes have the ability to act as a solubilizing agent for drugs with low aqueous solubility. However, a key limitation in exploiting liposome technology is the availability of scalable, low-cost production methods for the preparation of liposomes. Here we describe a new method, using microfluidics, to prepare liposomal solubilising systems which can incorporate low solubility drugs (in this case propofol). The setup, based on a chaotic advection micromixer, showed high drug loading (41 mol%) of propofol as well as the ability to manufacture vesicles with at prescribed sizes (between 50 and 450 nm) in a high-throughput setting. Our results demonstrate the ability of merging liposome manufacturing and drug encapsulation in a single process step, leading to an overall reduced process time. These studies emphasise the flexibility and ease of applying lab-on-a-chip microfluidics for the solubilisation of poorly water-soluble drugs.

Nanotechnology and microfluidics:formulation design and on-chip manufacture of nanoparticles

Nanoparticles offer an ideal platform for the delivery of small molecule drugs, subunit vaccines and genetic constructs. Besides the necessity of a homogenous size distribution, defined loading efficiencies and reasonable production and development costs, one of the major bottlenecks in translating nanoparticles into clinical application is the need for rapid, robust and reproducible development techniques. Within this thesis, microfluidic methods were investigated for the manufacturing, drug or protein loading and purification of pharmaceutically relevant nanoparticles. Initially, methods to prepare small liposomes were evaluated and compared to a microfluidics-directed nanoprecipitation method. To support the implementation of statistical process control, design of experiment models aided the process robustness and validation for the methods investigated and gave an initial overview of the size ranges obtainable in each method whilst evaluating advantages and disadvantages of each method. The lab-on-a-chip system resulted in a high-throughput vesicle manufacturing, enabling a rapid process and a high degree of process control. To further investigate this method, cationic low transition temperature lipids, cationic bola-amphiphiles with delocalized charge centers, neutral lipids and polymers were used in the microfluidics-directed nanoprecipitation method to formulate vesicles. Whereas the total flow rate (TFR) and the ratio of solvent to aqueous stream (flow rate ratio, FRR) was shown to be influential for controlling the vesicle size in high transition temperature lipids, the factor FRR was found the most influential factor controlling the size of vesicles consisting of low transition temperature lipids and polymer-based nanoparticles. The biological activity of the resulting constructs was confirmed by an invitro transfection of pDNA constructs using cationic nanoprecipitated vesicles. Design of experiments and multivariate data analysis revealed the mathematical relationship and significance of the factors TFR and FRR in the microfluidics process to the liposome size, polydispersity and transfection efficiency. Multivariate tools were used to cluster and predict specific in-vivo immune responses dependent on key liposome adjuvant characteristics upon delivery a tuberculosis antigen in a vaccine candidate. The addition of a low solubility model drug (propofol) in the nanoprecipitation method resulted in a significantly higher solubilisation of the drug within the liposomal bilayer, compared to the control method. The microfluidics method underwent scale-up work by increasing the channel diameter and parallelisation of the mixers in a planar way, resulting in an overall 40-fold increase in throughput. Furthermore, microfluidic tools were developed based on a microfluidics-directed tangential flow filtration, which allowed for a continuous manufacturing, purification and concentration of liposomal drug products.

DESCRIBING SLEEP AND SEDATION PRACTICES IN THE ICU: A MULTINATIONAL SURVEY

Introduction Sleep disturbances are common in critically ill patients treated in the intensive care unit (ICU) with the potential for serious consequences and long-term effects on health outcomes and patient morbidity.
Objectives Our aim was to describe sleep management and sedation practices of adult ICUs in ten countries and to evaluate roles and responsibilities of the ICU staff in relation to key sleep and sedation decisions.
Methods A multicenter, self-administered survey sent to nurse managers of adult ICUs across 10 countries. The questionnaire comprised four domains: sleep characteristics of the critically ill; sleep and sedation practices; non-pharmacological and pharmacological interventions used to improve sleep; and the autonomy and influence of nurses on sleeping practices in the ICU.
Results Overall response rate was 66% (range 32% UK to 100% Cyprus), providing data from 522 ICUs. In all countries, the most frequent patient characteristic perceived to identify sleep was lying quietly with closed eyes (N=409, 78%) (range 92% Denmark to 36% Italy). The most commonly used sedation scale was the Richmond Agitation-Sedation Score (RASS) (N=220, 42%) (range 81% UK to 0% Denmark, Cyprus where most ICUs used the Ramsay score). In most ICUs, selection of sleep medication (N=265, 51%) and assessment of effect (N=309, 59%) was performed by physicians and nurses based on collaborative discussion. In a minority of ICUs (N=161, 31%), decisions and assessments were made by physicians alone. The most commonly used (in all countries) non-pharmacological intervention to promote sleep was reducing ICU staff noise (N=473, 91%) (range 100% Denmark, Norway to 78% Canada). Only 95 ICUs (18%) used earplugs on a frequent basis (range 0% Greece, Cyprus, Denmark to 57% Sweden). Propofol was the drug used most commonly for sedation (N=359, 69%) (range 96% Sweden to 29% Canada). Chloral hydrate was used by only 63 (12%) ICUs (range 0% Greece, Cyprus, Denmark, Italy to 56% Germany). Sedation scales were used on a routine basis by 77% of the 522 ICUs. Participants scored nursing autonomy for sleep and sedation management as moderate; median score of 5 (scale of 0 to 10), range 7 (Canada, Greece, Sweden) to 4 (Norway, Poland). Nursing influence on sleep and sedation decisions was perceived considerable; median score 8, range 9 (Denmark) to 5 (Poland).
Conclusions We found considerable across country variation in sleep promotion and sedation management practices though most have adopted a sedation scale as recommended in professional society guidelines. Most ICUs in all countries used a range of pharmacological and non-pharmacological interventions to promote sleep. Most units reported inter-professional decision-making with nurses perceived to have substantial influence on sleep/sedation decisions.

Evaluación de cuatro protocolos anestésicos fijos en diferentes técnicas quirúrgicas en Caninos

El presente estudio se llevó a cabo en la clínica veterinaria ubicada en la Facultad de Ciencia Animal de la Universidad Nacional Agraria . Se determinaron diferentes variables a evaluar para comparar la acción de 4 distintos protocolos anestésicos en caninos, utilizando propofol, ketamina, d iazepam, xilacina 2%, m idazolam, sulfato de atropina, maleato de acepromacina y ketoprofeno mediantes los cuales se evaluó el comportamiento de los 14 pacientes quirúr gicos determinándose los siguientes resultados: La frecuencia respiratoria promedio en los diferentes tiempo s fue: pre operatorio : 76 – 20 con una media de 48 , trans operatorio : 56 – 10 con una media de 33 y post operatorio : 36 – 8 con una media de 22 movi mientos por minuto. La frecuencia cardiaca promedio en los diferente tiempos fue: pre operatorio : 140 – 40 con una media de 90 , trans operatorio : 180 – 64 con una media de 122 y post operatorio 160 - 40 con una media de 100 pulsaciones por minuto. La temper atura rectal promedio en los di ferentes tiempo fue: pre operatorio : 40.4 - 37. 5 con una media de 38.9 , trans operatorio : 40 – 37 con una media de 38.5 y post operatorio : 39.2 - 37.2 con una media de °C. El porcentaje de hematocrito promedio en los diferentes tiempos fue: pre operatorio : 47 – 25 con una media de 37 , trans operatorio : 3 9 – 24 con una media de 31.5 y post operatorio : 39 – 24 con una media de 31.5 % . Donde al comparar la acción de estos protocolos en los diferentes tiempos, no conllevaron a ninguno de los pacientes intervenidos a situaciones críticas que condujeran a emergencias en el intraoperatorio, concluyendo que los protocolos empleados tienen amplio margen de seguridad y garantizaro n integralmente los cuatro puntos cardinales de la anestesia

Síndrome Takotsubo após procedimento anestésico em idade pediátrica - um caso clínico

A síndrome Takotsubo (STT) é uma forma adquirida e transitória de disfunção sistólica, cuja apresentação clínica e eletrocardiográfica mimetiza um enfarte agudo do miocárdio. A STT é também conhecida como miocardiopatia de stress, síndrome do «coração partido», balonamento apical, insuficiência cardíaca aguda reversível, miocárdio «atordoado» (forma neurogénica) ou miocardiopatia aguda das catecolaminas. Os autores descrevem uma apresentação rara de STT após procedimento anestésico. Adolescente de 14 anos, sexo feminino, com antecedentes pessoais de enxaqueca hemiplé- gica e quisto pineal, submetida a ressonância magnética (RM) cranioencefálica de controlo. Durante a indução anestésica com propofol verificou-se bradicardia, revertida com atropina, seguida de taquidisritmia ventricular, revertida com lidocaína e murro pré-cordial. Nas primeiras horas de internamento evoluiu para edema pulmonar associado a insuficiência respiratória global por disfunção ventricular esquerda aguda. O ecocardiograma transtorácico mostrou dilatação do ventrículo esquerdo com hipocinesia global e fração de ejeção reduzida (< 30%). O eletrocardiograma revelou taquicardia sinusal persistente e alterações inespecíficas do segmento ST. Os biomarcadores cardíacos encontravam-se elevados (troponina 2,42 ng/ml, proBNP 8248 pg/ml). Foi medicada com diuréticos, IECA, digitálico e dopamina, com melhoria clínica, bioquímica e ecocardiográfica ao quarto dia. Os ecocardiogramas subsequentes mostraram normalização da função ventricular. A doente teve alta medicada com carvedilol, que suspendeu após normalização da função cardíaca e RM cardíaca não ter revelado alterações. Estão descritos poucos casos de STT em idade pediátrica. Alguns são desencadeados por patologia aguda do sistema nervoso central, mas nem todos cumprem os critérios de diagnóstico clássicos. Neste caso, o procedimento anestésico poderá ter desencadeado a STT.

Safety and risk factors for difficult endoscopist-directed ERCP sedation in daily practice: a hospital-based case-control study

Background: There are limited data concerning endoscopist-directed endoscopic retrograde cholangiopancreatography deep sedation. The aim of this study was to establish the safety and risk factors for difficult sedation in daily practice. Patients and methods: Hospital-based, frequency matched case-control study. All patients were identified from a database of 1,008 patients between 2014 and 2015. The cases were those with difficult sedations. This concept was defined based on the combination of the receipt of high-doses of midazolam or propofol, poor tolerance, use of reversal agents or sedation-related adverse events. The presence of different factors was evaluated to determine whether they predicted difficult sedation. Results: One-hundred and eighty-nine patients (63 cases, 126 controls) were included. Cases were classified in terms of high-dose requirements (n = 35, 55.56%), sedation-related adverse events (n = 14, 22.22%), the use of reversal agents (n = 13, 20.63%) and agitation/discomfort (n = 8, 12.7%). Concerning adverse events, the total rate was 1.39%, including clinically relevant hypoxemia (n = 11), severe hypotension (n = 2) and paradoxical reactions to midazolam (n = 1). The rate of hypoxemia was higher in patients under propofol combined with midazolam than in patients with propofol alone (2.56% vs. 0.8%, p < 0.001). Alcohol consumption (OR: 2.674 [CI 95%: 1.098-6.515], p = 0.030), opioid consumption (OR: 2.713 [CI 95%: 1.096-6.716], p = 0.031) and the consumption of other psychoactive drugs (OR: 2.015 [CI 95%: 1.017-3.991], p = 0.045) were confirmed to be independent risk factors for difficult sedation. Conclusions: Endoscopist-directed deep sedation during endoscopic retrograde cholangiopancreatography is safe. The presence of certain factors should be assessed before the procedure to identify patients who are high-risk for difficult sedation.

Awake examination versus DISE for surgical decision making in patients with OSA: A systematic review

OBJECTIVE: Traditionally, upper airway examination is performed while the patient is awake. However, in the past two decades, drug-induced sleep endoscopy (DISE) has been used as a method of tridimensional evaluation of the upper airway during pharmacologically induced sleep. This study aimed to systematically review the evidence regarding the usefulness of DISE compared with that of traditional awake examination for surgical decision making in patients with obstructive sleep apnea (OSA). DATA SOURCES: Scopus, PubMed, and Cochrane Library databases were searched. REVIEW METHODS: Only studies with a primary objective of evaluating the usefulness of DISE for surgical decision making in patients with OSA were selected. The included studies directly compared awake examination data with DISE outcome data in terms of possible influences on surgical decision making and operation success. RESULTS: A total of eight studies with 535 patients were included in this review. Overall, the surgical treatment changed after DISE in 50.24% (standard deviation 8.4) cases. These changes were more frequently associated with structures contributing to hypopharyngeal or laryngeal obstruction. However, these differences do not automatically indicate a higher success rate. CONCLUSION: This review emphasized the direct impact of DISE compared with that of awake examination on surgical decision making in OSA patients. However, it is also clear that the available published studies lack evidence on the association between this impact and surgical outcomes

Uso de dexmedetomidina como tratamiento coadyuvante de síndrome de abstinencia alcohólica: revisión sistemática

El objetivo de este estudio es establecer si la dexmedetomidina (DEX) es segura y efectiva para el manejo coadyuvante de síndrome de abstinencia a alcohol (SAA) a través de la búsqueda de evidencia científica. Metodología: se realiza una revisión sistemática de literatura publicada y no publicada desde enero de 1989 hasta febrero 2016 en PubMed, Embase, Scopus, Bireme, Cochrane library y en otras bases de datos y portales. Los criterios de inclusión fueron ensayos clínicos aleatorizados y no aleatorizados, estudios cuasi-experimentales, estudios de cohorte, y estudios de casos y controles; que incluyeron pacientes mayores de 18 años hospitalizados con diagnóstico de SAA y donde se usó DEX como terapia coadyuvante. Resultados: 7 estudios, 477 pacientes, se incluyeron en el análisis final. Se encontraron dos ensayos clínicos aleatorizados, tres estudios de casos y controles y dos estudios de cohorte retrospectivo. Solo uno de los estudios fue doble ciego y utilizó placebo como comparador. Análisis y conclusiones: en los estudios experimentales se determinan que el uso de DEX como terapia coadyuvante en el manejo de SAA tiene significancia clínica y estadística para disminuir dosis de BZD en las primeras 24 horas de tratamiento; pero no demostraron tener otros beneficios clínicos. En los estudios no aleatorizados existe consenso que relaciona el uso de DEX con menores dosis de BZD de forma temprana. Recomendaciones: no se recomienda el uso de DEX en SAA de forma rutinaria. Se recomienda usar DEX solo en casos en el que exista evidencia fallo terapéutico a BZD.

Incidencia de síndrome de abstinencia secundario a opioides y/o benzodiacepinas en dos unidades de cuidados intensivos pediátricos

• Introducción: El síndrome de abstinencia (SA) es el conjunto de síntomas y signos que se producen al suspender bruscamente la administración de un fármaco una vez se haya establecido dependencia física. • Objetivos: Caracterizar los pacientes que presentan SA secundario a opiodes (OP) y/o benzodiacepinas(BZ) durante la hospitalización en las unidades de cuidados intensivos pediátricos de la Clínica Infantil Colsubsidio (CIC) y Hospital del Niño de Panamá (HDN) del 1 de abril al 30 de septiembre del 2016. • Materiales y métodos: se realizó un estudio descriptivo, longitudinal, prospectivo. Incluimos 189 pacientes en la CIC y 144 pacientes en el HDN. Se utilizó la escala SOPHIA para el diagnóstico de SA, las escalas COMFORT para evaluar la sedación en pacientes ventilados no relajados y la escala FLACC para evaluar la analgesia. Se utilizó software StataV12® para el análisis estadístico. • Resultados: se reportó una incidencia global de SA de 6.1/100 días personas. La incidencia acumulada de SA fue de 56.08% y 29.86% para la CIC y el HDN respectivamente. En la CIC el 69.81% de los pacientes que requirieron infusión de OP y BZ desarrollaron SA. Se reportó una dosis acumulada de fentanyl de 530.34 ± 276.49 mcg/kg. Con respecto al HDN, de los pacientes que recibieron opioides y benzodiacepinas el 53.49 % desarrollaron SA. • Conclusión: El SA secundario a opioides y/o benzodiacepinas es frecuente en nuestras unidades con una incidencia variable, es mayor la presentación del SA al usar ambos fármacos, mayores dosis acumuladas y más días de infusión continua.