Intraventricular hemorrhage in very low birth weight infants: associated risk factors and outcome in the neonatal period

Intraventricular hemorrhage (IVH) is a severe complication in very low birth weight (VLBW) newborns (NB). With the purpose of studying the incidence of IVH, the associated risk factors, and the outcomes for these neonates, we studied all the VLBW infants born in our neonatal unit. Birth weight, gestational age, presence of perinatal asphyxia, mechanical ventilation, length of hospitalization, apnea crisis, hydrocephalus, and periventricular leukomalacia were analyzed. The diagnosis of IVH was based on ultrasound scan studies (Papile's classification) performed until the tenth day of life and repeated weekly in the presence of abnormalities. Sixty-seven/101 neonates were studied. The mortality rate was 30.6% (31/101) and the incidence of IVH was 29.8% (20/67) : 70% grade I, 20% grade III and 10% grade IV. The incidence of IVH in NB <1,000 g was 53.8% (p = 0.035) and for gestational age <30 weeks was 47.3% (p = 0.04), both considered risk factors for IVH. The length of hospitalization (p = 0.00015) and mechanical ventilation (p = 0.038) were longer in IHV NB. The IVH NB had a relative risk of 2.3 of developing apnea (p = 0.02), 3.7 of hydrocephalus (p = 0.0007), and 7.7 of periventricular leukomalacia (p < 0.00001). The authors emphasize the importance of knowing the risk factors related to IVH so as to introduce prevention schemes to reduce IVH and to improve outcomes of affected newborns.

Use of corticosteroids and the outcome of infants with bronchopulmonary dysplasia

Ventilator-dependent premature infants are often treated with dexamethasone. Several trials showed that steroids while improve pulmonary compliance and facilitate extubation, some treated infants may have adverse effects, such as alterations of growth curves. We conducted this retrospective study to evaluate the effects of steroids on mechanical ventilation, oxygen therapy, hospital length stay and mortality, in ventilator-dependent infants with bronchopulmonary dysplasia (BPD) (defined as the need of oxygen supplementation at 28 days of life). Twenty-six newborns with BPD were evaluated during 9 -- 42 days postpartum (mean = 31 days) and were divided into two groups: Group I - 14 newborns that did not receive dexamethasone, and Group II - 12 newborns that received dexamethasone at 14 --21 days of life. Dexamethasone was given at a dose of 0.25 mg per kilogram of body weight twice daily intravenously for 3 days, after which the dose was tapered. RESULTS: There were no statistically significant differences in the mean length of mechanical ventilation (Group I - 37 days, Group II - 35 days); oxygen supplementation (Group I - 16 days, Group II - 29 days); hospital stay (Group I - 72 days, Group II - 113 days); mortality (Group I - 35.7%, Group II - 41.6%). At birth, Group II was lighter (BW: Group I - 1154 grams ± 302, Group II - 791 grams ± 165; p < 0.05) and smaller (height: Group I - 37.22 cm ± 3.3, Group II - 33.5 ± 2.4; p< 0.05) than Group I. At 40 weeks, there were no statistically significant differences between groups in relation to anthropometric measurements. CONCLUSIONS: The use of corticosteroids in bronchopulmonary dysplasic infants may influence the somatic growth during its use. However, after its suspension, a recovery seems to occur, suggesting that its influence could be transitory.

Urinary tract infection in full-term newborn infants: risk factor analysis

OBJECTIVE: To analyze the correlation of risk factors to the occurrence of urinary tract infection in full-term newborn infants. PATIENTS AND METHODS: Retrospective study (1997) including full-term infants having a positive urine culture by bag specimen. Urine collection was based on: fever, weight loss > 10% of birth weight, nonspecific symptoms (feeding intolerance, failure to thrive, hypoactivity, debilitate suction, irritability), or renal and urinary tract malformations. In these cases, another urine culture by suprapubic bladder aspiration was collected to confirm the diagnosis. To compare and validate the risk factors in each group, the selected cases were divided into two groups: Group I - positive urine culture by bag specimen collection and negative urine culture by suprapubic aspiration, and Group II - positive urine culture by bag specimen collection and positive urine culture by suprapubic aspiration . RESULTS: Sixty one infants were studied, Group I, n = 42 (68.9%) and Group II, n = 19 (31.1%). The selected risk factors (associated infectious diseases, use of broad-spectrum antibiotics, renal and urinary tract malformations, mechanical ventilation, parenteral nutrition and intravascular catheter) were more frequent in Group II (p<0.05). Through relative risk analysis, risk factors were, in decreasing importance: parenteral nutrition, intravascular catheter, associated infectious diseases, use of broad-spectrum antibiotics, mechanical ventilation, and renal and urinary tract malformations. CONCLUSION: The results showed that parenteral nutrition, intravascular catheter, and associated infectious diseases contributed to increase the frequency of neonatal urinary tract infection, and in the presence of more than one risk factor, the occurrence of urinary tract infection rose up to 11 times.

Neuromuscular blockade in children

Neuromuscular blocking agents (NMBAs) have been widely used to control patients who need to be immobilized for some kind of medical intervention, such as an invasive procedure or synchronism with mechanical ventilation. The purpose of this monograph is to review the pharmacology of the NMBAs, to compare the main differences between the neuromuscular junction in neonates, infants, toddlers and adults, and moreover to discuss their indications in critically ill pediatric patients. Continuous improvement of knowledge about NMBAs pharmacology, adverse effects, and the many other remaining unanswered questions about neuromuscular junction and neuromuscular blockade in children is essential for the correct use of these drugs. Therefore, the indication of these agents in pediatrics is determined with extreme judiciousness. Computorized (Medline 1990-2000) and active search of articles were the mechanisms used in this review.

Earthen plasters based on illitic soils from Barrocal region of Algarve: contributions for building performance and sustainability

Clayish earth-based mortars can be considered eco-efficient products for indoor plastering since they can contribute to improve important aspects of building performance and sustainability. Apart from being products with low embodied energy when compared to other types of mortars used for interior plastering, mainly due to the use raw clay as natural binder, earth-based plasters may give a significant contribution for health and comfort of inhabitants. Due to high hygroscopicity of clay minerals, earth-based mortars present a high adsorption and desorption capacity, particularly when compared to other type of mortars for interior plastering. This capacity allows earth-based plasters to act as a moisture buffer, balancing the relative humidity of the indoor environment and, simultaneously, acting as a passive removal material, improving air quality. Therefore, earth-based plasters may also passively promote the energy efficiency of buildings, since they may contribute to decreasing the needs of mechanical ventilation and air conditioning. This study is part of an ongoing research regarding earth-based plasters and focuses on mortars specifically formulated with soils extracted from Portuguese ‘Barrocal’ region, in Algarve sedimentary basin. This region presents high potential for interior plastering due to regional geomorphology, that promote the occurrence of illitic soils characterized by a high adsorption capacity and low expansibility. More specifically, this study aims to assess how clayish earth and sand ratio of mortars formulation can influence the physical and mechanical properties of plasters. For this assessment four mortars were formulated with different volumetric proportions of clayish earth and siliceous sand. The results from the physical and mechanical characterization confirmed the significantly low linear shrinkage of all the four mortars, as well as their extraordinary adsorption-desorption capacity. These results presented a positive correlation with mortars´ clayish earth content and are consistent with the mineralogical analysis, that confirmed illite as the prevalent clay mineral in the clayish earth used for this study. Regarding mechanical resistance, although the promising results of the adhesion test, the flexural and compressive strength results suggest that the mechanical resistance of these mortars should be slightly improved. Considering the present results the mortars mechanical resistance improvement may be achieved through the formulation of mortars with higher clayish earth content, or alternatively, through the addition of natural fibers to mortars formulation, very common in this type of mortars. Both those options will be investigated in future research.

Assessing initial embodied energy in building structures using LCA methodology

The considerable amount of energy consumed on Earth is a major cause for not achieving sustainable development. Buildings are responsible for the highest worldwide energy consumption, nearly 40%. Strong efforts have been made in what concerns the reduction of buildings operational energy (heating, hot water, ventilation, electricity), since operational energy is so far the highest energy component in a building life cycle. However, as operational energy is being reduced the embodied energy increases. One of the building elements responsible for higher embodied energy consumption is the building structural system. Therefore, the present work is going to study part of embodied energy (initial embodied energy) in building structures using a life cycle assessment methodology, in order to contribute for a greater understanding of embodied energy in buildings structural systems. Initial embodied energy is estimated for a building structure by varying the span and the structural material type. The results are analysed and compared for different stages, and some conclusions are drawn. At the end of this work it was possible to conclude that the building span does not have considerable influence in embodied energy consumption of building structures. However, the structural material type has influence in the overall energetic performance. In fact, with this research it was possible that building structure that requires more initial embodied energy is the steel structure; then the glued laminated timber structure; and finally the concrete structure.

Relationship between the morphologic alterations of vocal cords from adult autopsies and the cause of death

PURPOSE: The purpose of this study was to identify the possible alteration in the thickness of the epithelium basal membrane of the vocal cords and correlate it with the cause of death. METHOD: Larynxes collected from adult autopsies during the period of 1993 to 2001 were utilized. We used the hematoxylin-eosin and periodic acid-Schiff staining methods for the morphological and morphometric analysis. RESULTS: Sixty-six vocal cords were analysed; increased thickness was identified in 14 cases (21.2%), with equal proportions between the genders. Increased vocal-cord thickness was more frequent in patients of the white ethnicity (12 cases, 85.7%). Respiratory alterations were found in 10 (71.4%) of the cases with increased vocal-cord thickness. Of the patients that were maintained with mechanical ventilation before death, 7 (18.4%) had thickening of the basal membrane. Among the smokers, 9 (19.63%) had basal membrane thickening. CONCLUSION: No statistically significant differences were found between the cases in which the cause of death was related to respiratory diseases as compared to non-respiratory diseases and the thickening of the basal membrane of the vocal cords. However, new studies are needed in order to verify the etiopathogenesis of this thickening.

Different doses of exogenous surfactant for treatment of meconium aspiration syndrome in newborn rabbits

OBJECTIVE: To evaluate the effects of 2 different doses of exogenous surfactant on pulmonary mechanics and on the regularity of pulmonary parenchyma inflation in newborn rabbits. METHOD: Newborn rabbits were submitted to tracheostomy and randomized into 4 study groups: the Control group did not receive any material inside the trachea; the MEC group was instilled with meconium, without surfactant treatment; the S100 and S200 groups were instilled with meconium and were treated with 100 and 200 mg/kg of exogenous surfactant (produced by Instituto Butantan) respectively. Animals from the 4 groups were mechanically ventilated during a 25-minute period. Dynamic compliance, ventilatory pressure, tidal volume, and maximum lung volume (P-V curve) were evaluated. Histological analysis was conducted using the mean linear intercept (Lm), and the lung tissue distortion index (SDI) was derived from the standard deviation of the means of the Lm. One-way analysis of variance was used with a = 0.05. RESULTS: After 25 minutes of ventilation, dynamic compliance (mL/cm H2O · kg) was 0.87 ± 0.07 (Control); 0.49 ± 0.04 (MEC*); 0.67 ± 0.06 (S100); and 0.67 ± 0.08 (S200), and ventilatory pressure (cm H2O) was 9.0 ± 0.9 (Control); 16.5 ± 1.7 (MEC*); 12.4 ± 1.1 (S100); and 12.1 ± 1.5 (S200). Both treated groups had lower Lm values and more homogeneity in the lung parenchyma compared to the MEC group: SDI = 7.5 ± 1.9 (Control); 11.3 ± 2.5 (MEC*), 5.8 ± 1.9 (S100); and 6.7 ± 1.7 (S200) (*P < 0.05 versus all the other groups). CONCLUSIONS: Animals treated with surfactant showed significant improvement in pulmonary mechanics and more regularity of the lung parenchyma in comparison to untreated animals. There was no difference in results after treatment with either of the doses used.

Hypophosphatemia in critically ill children

The purpose of this paper is to review clinical studies on hypophosphatemia in pediatric intensive care unit patients with a view to verifying prevalence and risk factors associated with this disorder. We searched the computerized bibliographic databases Medline, Embase, Cochrane Library, and LILACS to identify eligible studies. Search terms included critically ill, pediatric intensive care, trauma, sepsis, infectious diseases, malnutrition, inflammatory response, surgery, starvation, respiratory failure, diuretic, steroid, antiacid therapy, mechanical ventilation. The search period covered those clinical trials published from January 1990 to January 2004. Studies concerning endocrinological disorders, genetic syndromes, rickets, renal diseases, anorexia nervosa, alcohol abuse, and prematurity were not included in this review. Out of 27 studies retrieved, only 8 involved pediatric patients, and most of these were case reports. One clinical trial and one retrospective study were identified. The prevalence of hypophosphatemia exceeded 50%. The commonly associated factors in most patients with hypophosphatemia were refeeding syndrome, malnutrition, sepsis, trauma, and diuretic and steroid therapy. Given the high prevalence, clinical manifestations, and multiple risk factors, the early identification of this disorder in critically ill children is crucial for adequate replacement therapy and also to avoid complications.

Modern optimization in earthwork construction

Earthworks tasks are often regarded in transportation projects as some of the most demanding processes. In fact, sequential tasks such as excavation, transportation, spreading and compaction are strongly based on heavy mechanical equipment and repetitive processes, thus becoming as economically demanding as they are time-consuming. Moreover, actual construction requirements originate higher demands for productivity and safety in earthwork constructions. Given the percentual weight of costs and duration of earthworks in infrastructure construction, the optimal usage of every resource in these tasks is paramount. Considering the characteristics of an earthwork construction, it can be looked at as a production line based on resources (mechanical equipment) and dependency relations between sequential tasks, hence being susceptible to optimization. Up to the present, the steady development of Information Technology areas, such as databases, artificial intelligence and operations research, has resulted in the emergence of several technologies with potential application bearing that purpose in mind. Among these, modern optimization methods (also known as metaheuristics), such as evolutionary computation, have the potential to find high quality optimal solutions with a reasonable use of computational resources. In this context, this work describes an optimization algorithm for earthworks equipment allocation based on a modern optimization approach, which takes advantage of the concept that an earthwork construction can be regarded as a production line.

Predicting plateau pressure in intensive medicine for ventilated patients

Barotrauma is identified as one of the leading diseases in Ventilated Patients. This type of problem is most common in the Intensive Care Units. In order to prevent this problem the use of Data Mining (DM) can be useful for predicting their occurrence. The main goal is to predict the occurence of Barotrauma in order to support the health professionals taking necessary precautions. In a first step intensivists identified the Plateau Pressure values as a possible cause of Barotrauma. Through this study DM models (classification) where induced for predicting the Plateau Pressure class (>=30 cm

Intelligent decision support to predict patient barotrauma risk in intensive care units

The occurrence of Barotrauma is identified as a major concern for health professionals, since it can be fatal for patients. In order to support the decision process and to predict the risk of occurring barotrauma Data Mining models were induced. Based on this principle, the present study addresses the Data Mining process aiming to provide hourly probability of a patient has Barotrauma. The process of discovering implicit knowledge in data collected from Intensive Care Units patientswas achieved through the standard process Cross Industry Standard Process for Data Mining. With the goal of making predictions according to the classification approach they several DM techniques were selected: Decision Trees, Naive Bayes and Support Vector Machine. The study was focused on identifying the validity and viability to predict a composite variable. To predict the Barotrauma two classes were created: “risk” and “no risk”. Such target come from combining two variables: Plateau Pressure and PCO2. The best models presented a sensitivity between 96.19% and 100%. In terms of accuracy the values varied between 87.5% and 100%. This study and the achieved results demonstrated the feasibility of predicting the risk of a patient having Barotrauma by presenting the probability associated.

Numerical modeling and assessment of the thermal environment in an industrial premise of automotive components

Dissertação de mestrado em Engenharia Industrial

Indoor biological agents: evaluation of primary schools environments

Dissertação de mestrado em Human Engineering

Assessment of functional capacity through oxygen consumption in patients with asymptomatic probable heart disease

PURPOSE: To compare peak exercise oxygen consumption (VO2peak) of healthy individuals with asymptomatic individuals with probable heart disease. METHODS: Ninety-eight men were evaluated. They were divided into two groups: 1) 39 healthy individuals (group N) with an age range of 50±4.6 years; and 2) 59 asymptomatic individuals with signs of atherosclerotic and/or hypertensive heart disease (group C) with an age range of 51.9±10.4 years. In regard to age, height, body surface area, percentage of fat, lean body mass, and daily physical activity, both groups were statistically similar. Environmental conditions during the ergometric test were also controlled. RESULTS: Maximal aerobic power (watts), VO2peak, maximal heart rate, and maximal pulmonary ventilation were lower in group C (p<0.01) than in group N; weight, however, was lower in group N (p=0.031) than in group C. Differences in the respiratory gas exchange index, heart rate at rest, and the maximal double product of the two groups were not statistically significant. CONCLUSION: Signs of probable heart disease, even though asymptomatic, may reduce the functional capacity, perhaps due to the lower maximal cardiac output and/or muscle metabolic changes.