A lung computed tomographic assessment of positive end-expiratory pressure-induced lung overdistension

The aim of this study was to assess positive end-expiratory pressure (PEEP)-induced lung overdistension and alveolar recruitment in six patients with acute lung injury (ALI) using a computed tomographic (CT) scan method. Lung overdistension was first determined in six healthy volunteers in whom CT sections were obtained at FRC and at TLC with a positive airway pressure of 30 cm H2O. In patients, lung volumes were quantified by the analysis of the frequency distribution of CT numbers on the entire lung at zero end-expiratory pressure (ZEEP) and PEEP. In healthy volunteers at FRC, the distribution of the density histograms was monophasic with a peak at -791 ± 12 Hounsfield units (HU). The lowest CT number observed was -912 HU. At TLC, lung volume increased by 79 ± 35% and the peak CT number decreased to -886 ± 26 HU. More than 70% of the increase in lung volume was located below -900 HU, suggesting that this value can be considered as the threshold separating normal aeration from overdistension. In patients with ALI, at ZEEP the distribution of density histograms was either monophasic (n = 3) or biphasic (n = 3). The mean CT number was -319 ± 34 HU. At PEEP 13 ± 3 cm H2O, lung volume increased by 47 ± 19% whereas mean CT number decreased to -538 ± 171 HU. PEEP induced a mean alveolar recruitment of 320 ± 160 ml and a mean lung overdistension of 238 ± 320 ml. In conclusion, overdistended lung parenchyma of healthy volunteers is characterized by a CT number below -900 HU. This threshold can be used in patients with ALI for differentiating PEEP-induced alveolar recruitment from lung overdistension.

Effects of contrast material on computed tomographic measurements of lung volumes in patients with acute lung injury

Background. Intravenous injection of contrast material is routinely performed in order to differentiate nonaerated lung parenchyma from pleural effusion in critically ill patients undergoing thoracic computed tomography (CT). The aim of the present study was to evaluate the effects of contrast material on CT measurement of lung volumes in 14 patients with acute lung injury. Method. A spiral thoracic CT scan, consisting of contiguous axial sections of 10 mm thickness, was performed from the apex to the diaphragm at end-expiration both before and 30 s (group 1; n=7) or 15 min (group 2; n=7) after injection of 80 ml contrast material. Volumes of gas and tissue, and volumic distribution of CT attenuations were measured before and after injection using specially designed software (Lungview®; Institut National des Télécommunications, Evry, France). The maximal artifactual increase in lung tissue resulting from a hypothetical leakage within the lung of the 80 ml contrast material was calculated. Results. Injection of contrast material significantly increased the apparent volume of lung tissue by 83 ± 57 ml in group 1 and 102 ± 80 ml in group 2, whereas the corresponding maximal artifactual increases in lung tissue were 42 ± 52 ml and 31 ± 18 ml. Conclusion. Because systematic injection of contrast material increases the amount of extravascular lung water in patients with acute lung injury, it seems prudent to avoid this procedure in critically ill patients undergoing a thoracic CT scan and to reserve its use for specific indications.

Efeito da posição do prematuro no desmame da ventilação mecânica

Objective: the purpose of this study was to determine the effects of prone positioning on cardiorespiratory stability and weaning outcome of preterm infants during weaning from mechanical ventilation. Methods: from January to December 1999, a sample of 42 preterm infants, with birthweight < 2,000 g, mechanically ventilated in the first week of life, were randomly divided, in the beginning of the weaning process, in two groups according to the position: supine position (n = 21) or prone position (n = 21). Heart rate, respiratory rate, transcutaneous oxygen saturation and ventilatory parameters were recorded every one hour. Length of the weaning process and complications were also assessed. Results: in both groups the mean gestational age was 29 weeks, most of the patients presented very low birthweight and respiratory distress syndrome. The mean length of the weaning process was 2 days. There were no differences between the groups regarding respiratory rate, heart rate and transcutaneous oxygen saturation, however, oxygen desaturation episodes were more frequent in supine position (p = 0.009). Ventilatory parameters decreased faster and reintubation was less frequent in the prone group (4% versus 33%). No adverse effects of prone positioning were observed. Conclusion: these results suggest that prone position is a safe and beneficial procedure during the weaning from mechanical ventilation and may contribute to weaning success in preterm infants.

Uso do óxido nítrico em pediatria

Objective: To review the literature on inhaled nitric oxide and to describe its main clinical applications in pediatrics. Sources of data: A 10 year literature review with selection of the most important publications on inhaled nitric oxide, using the Medline and Cochrane Systematic Review databases. Summary of the findings: This review was organized as follows: introduction; metabolism and biological effects; clinical applications; dosage, gas administration and weaning; precautions and side-effects. Inhaled nitric oxide use was described in persistent pulmonary hypertension and hypoxia of the newborn, acute respiratory distress syndrome, primary pulmonary hypertension, heart surgery, chronic obstructive pulmonary disease, sickle cell anemia, and bronchospastic disease. Conclusions: Inhaled nitric oxide is a therapeutic approach with wide clinical applications in pediatrics. Its use is safe when administered in pediatric intensive care units under strict monitoring. As a pulmonary vasodilator, nitric oxide has beneficial effects on gas exchange and ventilation. Controlled trials, focusing on early gas administration should be performed under many clinical conditions, especially acute respiratory distress syndrome.

Preeclampsia: Early and late neonatal outcomes

Newborn infants exposed to preeclampsia (PE) present increased short-term morbidity, mainly respiratory diseases such as respiratory distress syndrome and bronchopulmonary dysplasia. Gastrointestinal problems are also frequent, although a higher risk of necrotizing enterocolitis has not been confirmed. These problems could be related not just to PE itself but also to prematurity or intrauterine growth restriction, which frequently occur in this maternal disease. Other findings, however, seem to be due to the direct effect of the maternal disease; these findings include an increased frequency of neutropenia and thrombocytopenia and a lower incidence of cerebral disorders, such as periventricularintraventricular hemorrhage and cerebral palsy. The evaluation of long-term outcome shows increasing evidence that PE has important implications for the future health of the mother and her child, suggesting that PE is not a simple gestational disorder but a clinical syndrome with an unclear etiology, a genetic component, and a complex pathophysiology. This syndrome involves important maternal and fetal vascular alterations that can persist and cause diseases in later life. The divergence in results on outcomes for children exposed to PE could, in part, be due to methodological differences in the studies, most of which are retrospective case-control studies. Better evidence on prognosis is obtained from cohort studies. Even in the cohort studies, differences in patient characteristics and severity of maternal disease, as well as sample size, follow-up time, and main outcome measures certainly contribute to the variability in results reported in the literature. © 2012 by the American Academy of Pediatrics. All rights reserved.

Congenital diaphragmatic Bochdaleck hernia: Case report

Congenital diaphragmatic Bochdaleck hernia is an anatomical defect of the diaphragm, which allows protrusion of abdominal viscera into the chest, causing serious pulmonary and cardiac complications in the neonate. In this study we aimed to present a case of congenital Bochdaleck hernia. We investigated a 40 weeks old child, with a pregnancy carried out in a public hospital in Passo Fundo, Rio Grande do Sul, Brazil. We suggest that if diagnosis occurs in the prenatal period, the prognosis of this disease improves. As a consequence, it allows the parity of the fetus to occur in a higher complexity center, optimizing the chances of survival. © 2012 Lava et al.; licensee BioMed Central Ltd.

Annexin-A1 peptide down-regulates the leukocyte recruitment and up-regulates interleukin-10 release into lung after intestinal ischemia-reperfusion in mice

Background: Intestinal ischemia/reperfusion (IR) injury is a serious and triggering event in the development of remote organ dysfunction, from which the lung is the main target. This condition is characterized by intense neutrophil recruitment, increased microvascular permeability. Intestinal IR is also responsible for induction of adult respiratory distress syndrome, the most serious and life-threatening form of acute lung injury. The purpose of this study was to investigate the effect of annexin-A1 protein as an endogenous regulator of the organ remote injury induced by intestinal ischemia/reperfusion. Male C57bl/6 mice were subjected to intestinal ischemia, induced by 45 min occlusion of the superior mesenteric artery, followed by reperfusion. Results: The intestinal ischemia/reperfusion evoked a high intensity lung inflammation as indicated by the number of neutrophils as compared to control group. Treatment with annexin-A1 peptidomimetic Ac2-26, reduced the number of neutrophils in the lung tissue and increased its number in the blood vessels, which suggests a regulatory effect of the peptide Ac2-26 in the neutrophil migration. Moreover, the peptide Ac2-26 treatment was associated with higher levels of plasma IL-10. Conclusion: Our data suggest that the annexin-A1 peptidomimetic Ac2-26 treatment has a regulatory and protective effect in the intestinal ischemia/reperfusion by attenuation of the leukocyte migration to the lung and induction of the anti-inflammatory cytokine IL-10 release into the plasma. The anti-inflammatory action of annexin-A1 and its peptidomimetic described here may serve as a basis for future therapeutic approach in mitigating inflammatory processes due to intestinal ischemia/reperfusion. © 2013 Guido et al.; licensee BioMed Central Ltd.

Comparação entre ventilação mandatória intermitente e ventilação mandatória intermitente sincronizada compressão de suporte em crianças

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparação entre posiçao prona e posiçao supina, associadas à ventilação oscilatória de alta frequência, em modelo experimental de lesão pulmonar aguda

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Efeito do óxido nítrico inalatório associado à ventilação mecânica protetora na lesão pulmonar aguda induzida experimentalmente

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparação dos efeitos da posição prona associada à ventilação oscilatória de alta frequência e à mecânica convencional protetora em lesão pulmonar aguda induzida experimentalmente

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Na companhia do vírus: concepções e vivências de adolescentes portadores do HIV/Aids

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Doenças respiratórias neonatais em prematuros de mães hipertensas e normotensas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Distribuição regional de gás e tecido na síndrome da angústia respiratória aguda: consequências do efeito da pressão expiratória final positiva

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência da terapia pré-natal com betametasona sobre o desenvolvimeto da prole, do nascimento à vida adulta reprodutiva, em ratos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)