Age-related differences in network structure and dynamic synchrony of cognitive control.

Cognitive trajectories vary greatly across older individuals, and the neural mechanisms underlying these differences remain poorly understood. Here, we investigate the cognitive variability in older adults by linking the influence of white matter microstructure on the task-related organization of fast and effective communications between brain regions. Using diffusion tensor imaging and electroencephalography, we show that individual differences in white matter network organization are associated with network clustering and efficiency in the alpha and high-gamma bands, and that functional network dynamics partly explain individual differences in cognitive control performance in older adults. We show that older individuals with high versus low structural network clustering differ in task-related network dynamics and cognitive performance. These findings were corroborated by investigating magnetoencephalography networks in an independent dataset. This multimodal (fMRI and biological markers) brain connectivity framework of individual differences provides a holistic account of how differences in white matter microstructure underlie age-related variability in dynamic network organization and cognitive performance.

O papel terapêutico do Programa Farmácia Viva e das plantas medicinais / The therapeutic role of the Program Farmacia Viva and the medicinal plants in the center-south of Piauí

RESUMOEste trabalho realizou um levantamento sobre o uso de plantas medicinais na cidade de Picos-PI, identificou as plantas cultivadas no horto pertencente ao Laboratório Fitoterápico de Picos (LAFIPI), e analisou o uso de fitoterápicos dispensados pelo Programa Farmácia Viva no triênio 2008-2010. Do total dos 750 entrevistados, 37,6% foram homens e 62,4 % mulheres, dentre os quais a maioria não concluiu o segundo grau (69,2%) e 77,2% possuíam renda mensal de até dois salários mínimos. Com relação ao consumo de plantas medicinais, 76,3% afirmaram utilizá-las para tratar doenças, principalmente por considerá-las mais saudáveis (84,8%). A indicação do uso foi orientada, sobretudo, por familiares (82,2%), embora a maioria adquira as plantas em feiras livres (32,8%). Das 127 plantas relatadas, as mais citadas foram erva-cidreira, boldo e hortelã, sendo as folhas a parte mais utilizada (42,3%), predominantemente por infusão (39,4%). As aplicações mais lembradas foram para tratar dores em geral (17%), distúrbios respiratórios (16,5%) e digestivos (16%). As espécies mais cultivadas no horto são chambá (Justicia pectoralis), alecrim pimenta (Lippia sidoides), malva santa (Plectranthus barbatus) e erva cidreira (Lippia alba). O lambedor de chambá foi o fitoterápico mais procurado pela população entre 2008 e 2010. Esse estudo descreveu, pela primeira vez, o uso tradicional de plantas medicinais no município de Picos e demonstrou, também de forma inédita, a relevância de investimentos do Programa Farmácia Viva no município de Picos e sua inclusão no Programa Saúde da Família como forma de disponibilizar à população de baixa renda fitoterápicos produzidos localmente a custos reduzidos.

ABSTRACTThis study performed a research about the use of medicinal plants in Picos city, identifying the plants grown in the garden belonging to the Laboratory of Phytotherapics in Picos (LAFIPI) and analying the use of phytotherapics distributed by the Farmácia Viva Project between 2008-2010. From the total of 750 interviewed participants, 37.6% were men and 62.4 % women. Most of them do not have secondary education (69.2%) and 77.2% had an income of up until two minimum wages. Regarding consumption of medicinal plants, 76.3 % used them to treat diseases, mainly because they considered them to be healthier (84.8%). The indication of use of the plants was mainly suggested by relatives (82.2%), even though the majority of the participants acquires plants in open markets (32.8%). From the 127 plants mentioned, the most cited ones were balm, boldo and mint, and leaves were the most utilized parts (42.3%), predominantly by infusion (39.4%). The most common reasons for the usewere to treat pain in general (17%), and respiratory (16.5%) and digestive disorders (16%). The most cultivated species in the garden were chambá (Justicia pectoralis), alecrim pimenta (Lippia sidoides), malva santa (Plectranthus barbatus) and erva cidreira (Lippia alba). The "chambá licker" was the most herbal medicine searched by the population between 2008 and 2010. This investigation described, for the first time, the traditional use of medicinal plants in Picos and demonstrated,alsounprecedentedly, the relevance of investments in the Farmácia Viva Project in Picos city and its inclusion in the Family Health Program as a strategyin order to provide locally producedphytotherapics for low-income population at low costs.

Influence of age, disease onset and ApoE4 on visual medial temporal lobe atrophy cut-offs.

BACKGROUND: Visual assessment of medial temporal lobe atrophy (MTA; range 0-4, from no atrophy to increasing atrophy of the choroid fissure, temporal horns and hippocampus) is a sensitive radiological marker of Alzheimer's disease (AD). One of the critical elements for visual MTA assessment is the cut-off score that determines deviation from normality. METHODS: In this study, we assessed the sensitivity and specificity of different MTA cut-off scores to classify control subjects, individuals with mild cognitive impairment (MCI) and AD patients from two large independent cohorts, AddNeuroMed and Alzheimer's Disease Neuroimaging Initiative. Of note, we evaluated the effects of clinical, demographic and genetic variables on the classification performance according to the different cut-offs. RESULTS: A cut-off of ≥1.5 based on the mean MTA scores of both hemispheres showed higher sensitivity in classifying patients with AD (84.5%) and MCI subjects (75.8%) who converted to dementia compared to an age-dependent cut-off. The age-dependent cut-off showed higher specificity or ability to correctly identify control subjects (83.2%) and those with MCI who remained stable (65.5%). Increasing age, early-onset disease and absence of the ApoE ε4 allele had a stronger influence on classifications using the ≥1.5 cut-off. Above 75 years of age, an alternative cut-off of ≥2.0 should be applied to achieve a classification accuracy for both patients with AD and control subjects that is clinically useful. CONCLUSION: Clinical, demographic and genetic variables can influence the classification of MTA cut-off scores, leading to misdiagnosis in some cases. These variables, in addition to the differential sensitivity and specificity of each cut-off, should be carefully considered when performing visual MTA assessment.

A randomized, double-blind, and placebo-controlled study with tranexamic acid of bleeding and fibrinolytic activity after primary coronary artery bypass grafting.

Cardiopulmonary bypass is frequently associated with excessive blood loss. Platelet dysfunction is the main cause of non-surgical bleeding after open-heart surgery. We randomized 65 patients in a double-blind fashion to receive tranexamic acid or placebo in order to determine whether antifibrinolytic therapy reduces chest tube drainage. The tranexamic acid group received an intravenous loading dose of 10 mg/kg, before the skin incision, followed by a continuous infusion of 1 mg kg(-1) h(-1) for 5 h. The placebo group received a bolus of normal saline solution and continuous infusion of normal saline for 5 h. Postoperative bleeding and fibrinolytic activity were assessed. Hematologic data, convulsive seizures, allogeneic transfusion, occurrence of myocardial infarction, mortality, allergic reactions, postoperative renal insufficiency, and reopening rate were also evaluated. The placebo group had a greater postoperative blood loss (median (25th to 75th percentile) 12 h after surgery (540 (350-750) vs 300 (250-455) mL, P = 0.001). The placebo group also had greater blood loss 24 h after surgery (800 (520-1050) vs 500 (415-725) mL, P = 0.008). There was a significant increase in plasma D-dimer levels after coronary artery bypass grafting only in patients of the placebo group, whereas no significant changes were observed in the group treated with tranexamic acid. The D-dimer levels were 1057 (1025-1100) microg/L in the placebo group and 520 (435-837) microg/L in the tranexamic acid group (P = 0.01). We conclude that tranexamic acid effectively reduces postoperative bleeding and fibrinolysis in patients undergoing first-time coronary artery bypass grafting compared to placebo.

A randomized, double-blind, and placebo-controlled study with tranexamic acid of bleeding and fibrinolytic activity after primary coronary artery bypass grafting

Cardiopulmonary bypass is frequently associated with excessive blood loss. Platelet dysfunction is the main cause of non-surgical bleeding after open-heart surgery. We randomized 65 patients in a double-blind fashion to receive tranexamic acid or placebo in order to determine whether antifibrinolytic therapy reduces chest tube drainage. The tranexamic acid group received an intravenous loading dose of 10 mg/kg, before the skin incision, followed by a continuous infusion of 1 mg kg-1 h-1 for 5 h. The placebo group received a bolus of normal saline solution and continuous infusion of normal saline for 5 h. Postoperative bleeding and fibrinolytic activity were assessed. Hematologic data, convulsive seizures, allogeneic transfusion, occurrence of myocardial infarction, mortality, allergic reactions, postoperative renal insufficiency, and reopening rate were also evaluated. The placebo group had a greater postoperative blood loss (median (25th to 75th percentile) 12 h after surgery (540 (350-750) vs 300 (250-455) mL, P = 0.001). The placebo group also had greater blood loss 24 h after surgery (800 (520-1050) vs 500 (415-725) mL, P = 0.008). There was a significant increase in plasma D-dimer levels after coronary artery bypass grafting only in patients of the placebo group, whereas no significant changes were observed in the group treated with tranexamic acid. The D-dimer levels were 1057 (1025-1100) æg/L in the placebo group and 520 (435-837) æg/L in the tranexamic acid group (P = 0.01). We conclude that tranexamic acid effectively reduces postoperative bleeding and fibrinolysis in patients undergoing first-time coronary artery bypass grafting compared to placebo.

Brazilian isolates of Trypanosoma cruzi from humans and triatomines classified into two lineages using mini-exon and ribosomal RNA sequences.

Traditional molecular and biochemical methods, such as schizodeme analysis, karyotyping, DNA fingerprinting, and enzyme electrophoretic profiles, have shown a large variability among Trypanosoma cruzi isolates. In contrast to those results, polymerase chain reaction (PCR) amplification of sequences from the 24S alpha ribosomal RNA gene and from the mini-exon gene nontranscribed spacer indicated a dimorphism among T. cruzi isolates, which enabled the definition of two major parasite lineages. In the present study, 86 T. cruzi field stocks (68 isolated from humans with defined presentations of Chagas' disease and 18 from triatomines) derived from four Brazilian geographic areas were typed by the PCR assay based on the DNA sequences of the mini-exon and 24S alpha rRNA genes. These stocks were ordered into the two major T. cruzi lineages. Lineage 1 was associated mainly with human isolates and lineage 2 with the sylvatic cycle of the parasite.

Trypanosoma cruzi: parasite detection and strain discrimination in chronic chagasic patients from northeastern Brazil using PCR amplification of kinetoplast DNA and nonradioactive hybridization.

Blood samples from 172 individuals from northeastern Brazil were subjected to PCR amplification of Trypanosoma cruzi-specific kDNA sequences. This method enabled us to detect parasite DNA in 21 of 47 patients that were serologically positive. In addition, 1 patient that gave doubtful results with chagasic serology was confirmed as positive by PCR. We applied the same PCR detection method to the feces of wild triatomines captured in the same region, obtaining three positive results that were confirmed by microscopic examination. The 25 amplified products obtained in this study were then reamplified with primers that gave a final amplicon containing sequences from the most variable region of kDNA minicircles. These were used as probes in hybridization experiments aimed at defining the degree of relatedness between the strains infecting humans and insects based on kDNA homologies. We found that the amplification products from the three triatomines were related and showed no cross-hybridization with those obtained from human infections. Eight amplified products from human infections showed no cross-hybridization and did not hybridize with products from other patients. This indicates that the strains of T. cruzi circulating in the region present a high level of genetic heterogeneity. Finally, a number of amplified products hybridized with amplicons that did not hybridize with each other, indicating that infections with a parasite population presenting a mixed kDNA content (either due to different strains of T. cruzi or to a hybrid parasite) are a more frequent event than previously thought.

Schistosomiasis in a low prevalence area: incomplete urbanization increasing risk of infection in Paracambi, RJ, Brazil.

The risk of schistosomiasis infection and heavy infection in the locality of Sabugo was evaluated in relation to housing in areas with different urbanization development and to residential supply with snail-infested water. Critical sanitary conditions were found in areas of incomplete urbanization, where healthy water supply sources were scarce, and draining of sewage, without previous treatment, was made directly to the water-bodies used for domestic and leisure activities, despite being Biomphalaria tenagophila snail breeding-places. Stool examinations (Kato-Katz and Lutz methods) showed prevalence of 2.9% mean intensity of 79 eggs per gram of stool and 47% of positive cases presenting intense infection. The use of snail-contaminated water for domestic purposes was considered a risk factor for infection. It is concluded that incomplete urbanization would facilitate transmission, probably enhancing the intensity of infection and that a low prevalence could hide a highly focal transmission. The relevance of these facts upon the efficiency of epidemiologic study methods and disease control planning are then discussed.

Use of a simplified polymerase chain reaction procedure to detect Trypanosoma cruzi in blood samples from chronic chagasic patients in a rural endemic area.

The feasibility of using DNA amplification by the polymerase chain reaction (PCR) for specific detection of Trypanosoma cruzi in human blood specimens was investigated. One hundred blood samples were collected in an endemic area of Minas Gerais, Brazil. They were submitted to DNA extraction and PCR amplification with kinetoplast DNA-specific primers using a simplified boiling procedure that linearized most minicircle molecules without the aid of chemical reagents. Samples that gave negative results were checked for possible inhibition of amplification using primers derived from a human-specific sequence, and those showing some level of inhibition were retested after a new DNA extraction. Of 86 patients previously diagnosed as chagasic by serologic techniques, 83 were positive in our PCR test (sensitivity = 96.5%), including all the xenodiagnosis-positive patients and 21 (87.5%) of 24 xenodiagnosis-negative individuals. In addition, four of six patients with doubtful serologic results were confirmed as positive by PCR. Our results suggest that the PCR may be a useful complement to serology in the diagnosis of Chagas' disease, and that it is the most powerful technique available for parasite detection in patients with chronic disease.

Serodiagnosis of Chagas' disease by enzyme-linked immunosorbent assay using two synthetic peptides as antigens.

An enzyme-linked immunosorbent assay (ELISA) was developed for detecting antibodies against Trypanosoma cruzi. Two synthetic T. cruzi peptides, TcD and PEP2, were used. The specificity and sensitivity of the peptide ELISA were determined with 260 serum samples from individuals living in an area in which Chagas' disease is endemic. ELISAs were performed with the peptides singly or in combination. The evaluation of these tests showed that 168 (93.8%) of 179 serum samples from T. cruzi-infected patients were positive when TcD peptide was used as antigen; 164 (91.6%) samples were positive with PEP2, and 178 (99.4%) samples were positive when the two peptides were combined. Thus, the sensitivity of the ELISA using the two peptides exceeded 99%. The specificity was evaluated by using a panel of 118 serum samples that included samples from 81 individuals living in an area of endemicity with negative serology for Chagas' disease and from 37 patients from areas in which T. cruzi was not endemic but with other pathologies, such as leishmaniasis, tuberculosis, and leprosy. Only two false-positive serum samples were found in this group of individuals, giving a test specificity of more than 98%. Because these peptides can be synthesized and are very stable at room temperature, the use of such reagents can improve the standardization and reproducibility of ELISAs for the serodiagnosis of T. cruzi infection.

Chagas' disease diagnosis: evaluation of several tests in blood bank screening.

Blood transfusion is one of the principal routes of transmission of Chagas' disease, a major endemic disease in Latin America. Methods for blood screening are not accurate and may yield false results that lead to high social and economic costs. This study compares two methods of diagnosing Chagas' disease (indirect immunofluorescence and hemagglutination) and several enzyme-linked immunosorbent assays (ELISAs) with regard to specificity and sensitivity, by using human sera with known serologic and parasitologic characteristics, as well as samples with discrepant results on conventional serologic tests. An ELISA using recombinant antigens showed no cross-reactivity with sera that were positive for other diseases. All evaluated ELISAs performed well, and their use may lead to a reduction of more than 50 percent in the number of discordant sera. Further improvements are needed in view of the complexity of the serologic diagnosis of Chagas' disease.

Detection of Trypanosoma cruzi in blood specimens of chronic chagasic patients by polymerase chain reaction amplification of kinetoplast minicircle DNA: comparison with serology and xenodiagnosis.

A panel of 114 blood samples from chronic chagasic patients and nonchagasic patients was screened for Trypanosoma cruzi by xenodiagnostic, serologic, and polymerase chain reaction (PCR) amplification tests. Blood samples were preserved in a guanidine-EDTA buffer, and total blood DNA was isolated after chemical nuclease cleavage with 1,10-phenanthroline-copper ion and used as a template for PCR amplification of the conserved and variable regions of T. cruzi minicircle molecules. The PCR products were screened by Southern blot hybridization with a digoxigenin-labeled oligonucleotide probe specific for the conserved region of the minicircle. The method showed a sensitivity of 100% compared with the serologic test. In addition, all of the serology-positive, xenodiagnosis-negative samples were positive by PCR. This demonstrates that PCR amplification of T. cruzi kinetoplast minicircle DNA could replace xenodiagnosis for evaluation of parasitemia in chronic chagasic patients and could serve as a complement for serologic testing in the screening of blood bank donors.

Surgical repair of ventricular aneurysms. Early results with Cooley's technique.

Using bovine pericardium instead of Dacron for grafting, we performed ventricular endoaneurysmorrhaphy (Cooley's technique) in 13 patients with postmyocardial infarction left ventricular aneurysm. Twelve patients were men and 1 was a woman; their ages ranged from 38 to 67 years (mean, 51.2 +/- 11.4 years). Eight patients had large anterolateral aneurysms, 4 had apical aneurysms, and 1 had a false inferior aneurysm. Postoperatively, the mean cardiac index increased from 2.07 +/- 0.50 to 3.09 +/- 0.99 L/min/m2 (p < 0.05), with a mean percentage increase of 50.17% +/- 37.03%. No patient required postoperative mechanical circulatory assistance, and pharmacologic support could be withdrawn soon after surgery. All patients had uncomplicated recoveries and were asymptomatic upon discharge, at a mean time of 9.0 +/- 2.3 days after surgery. We conclude that ventricular endoaneurysmorrhaphy provides excellent initial results, and we believe, through subjective analysis of ventriculograms, that the use of bovine pericardium for grafting produces better functional results than does the use of Dacron.

Use of recombinant antigens for the accurate immunodiagnosis of Chagas' disease.

We tested two Trypanosoma cruzi recombinant antigens in a diagnostic test for Chagas' disease. These antigens were a cytoplasmic repetitive antigen (CRA) and a flagellar repetitive antigen (FRA). The results indicate that the recombinant antigens give better results when used in combination than when used separately, and that the removal of the beta-galactosidase portion of the recombinant fusion proteins increases the specificity of the diagnostic test for Chagas' disease. In addition, a direct enzyme-linked immunosorbent assay (ELISA), which involves the use of peroxidase-labeled antigens to detect the immune-complexes, was developed and compared with a conventional ELISA. The results indicate that the recombinant (CRA+FRA) ELISA is better than the conventional ELISA in the diagnosis of Chagas' disease, providing 100% specificity and sensitivity in all sera tested to date. The recombinant ELISA was compared with conventional serologic tests (hemagglutination and immunofluorescence) for Chagas' disease diagnosis, and the results show that the recombinant ELISA does not give rise to false-positive results that are observed with the two other tests. The use of the recombinant ELISA should be useful in the prevention of transmission of Chagas' disease by blood transfusions.

[The evolution of chronic chagasic cardiopathy. I. The influence of parasitemia]. / Evolução da cardiopatia chagásica crônica. I--Influência da parasitemia.

During eight years (1982-1990) the evolution of chronic chagasic cardiopathy and its relation to parasitemia was evaluated in 279 patients, 85 men and 194 women, studied by resting electrocardiography and xenodiagnosis. All patients were residents in Virgem da Lapa, State of Minas Gerais, Brazil and their ages varied from 7 to 76 years (average 42.6 y). According to the results of the electrocardiograms the evolution of chagasic cardiopathy was classified as a) unchanged--when there was no change of the initial pattern off the ECG, b) progressive--when there was deterioration of the ECG pattern and c) regressive-when there was normalization or regression of the ECG alterations. Regarding xenodiagnosis 120 were considered with positive parasitemia, one or more xenodiagnoses positive, and 159 with negative parasitemia--all xenodiagnoses negative. The results showed: a) chagasic cardiopathy unchanged in 172 (61.6%) patients, b) progressive in 99 (35.5%) patients and c) regressive in 8 (2.9%). There was no relation between the evolution of chagasic cardiopathy and parasitemia. Independent from parasitemia, the cardiopathy was progressive according to the age of the patients and significantly greater in males. In conclusion we can state that evolution of chronic chagasic cardiopathy is associated with the age and with the male sex, but not with parasitemia, and this may suggest that parasitemia is not related to the development of the chronic chagasic cardiopathy.

[Modified Cooley technique for surgical repair of left ventricular aneurysms]. / Técnica de Cooley modificada para a correção cirúrgica de aneurismas do ventrículo esquerdo.

PURPOSE: To evaluate early postoperative results of modified Cooley's technique of ventricular endoaneurysmorrhaphy. PATIENTS AND METHODS: Eight patients, seven males, with ages ranging 38.0 to 67.0 years (m = 51.2 +/- 11.4 years) and with postinfarction left ventricular aneurysms were submitted to surgical repair by a modified Cooley's technique of ventricular endoaneurysmorrhaphy. RESULTS: No postoperative complication occurred and all patients were discharged from the hospital asymptomatic on a mean time of 9.0 +/- 2.3 days after surgery. The mean cardiac index increased from 2.1 +/- 0.5 to 3.3 +/- 1.1 l/min (p less than 0.05) with a mean percentual increase of 53.0%. No patient required mechanical circulatory assistance after surgery and the pharmacological support could be interrupted soon. CONCLUSION: Ventricular endoaneurysmorrhaphy searchs to restore shape, contour and volume to the left ventricle and has shown excellent initial results.

[Development of chronic human chagas cardiopathy in the hinterland of the Paraíba State, Brazil, in a 4.5 year period]. / Evolução da cardiopatia chagásica crônica humana no Sertão do Estado da Paraíba, Brasil, no período de 4,5 anos.

Two sectional studies about chronic Chagas' disease were performed at a 4.5 year interval, involving the urban populations of Agua Branca, Catingueira, Emas, Imaculada, Mãe D'Agua, Olho D'Agua, Piancó and São José de Caiana counties in the Sertão region of the State of Paraíba. The evolution of heart disease was evaluated in 125 matched pairs of chronic chagasic and non-chagasic patients of the same sex, age and county of origin through electrocardiograms (ECG) at rest. The following evaluation criteria were considered: unchanged - no change in the original ECG pattern; progressive-changes in ECG pattern from normal to abnormal or deterioration of ECG abnormalities; and ECG normalization. In chagasic patients evolution of the disease was unchanged in 101 (80.8%), progressive in 13 (10.4%) and ECG normalization in 11 (8.8%), while those observed in non-chagasic patients were respectively values 117 (93.6%), 6 (4.8%) and 2%) patients. Findings indicate that the share of Chagas-linked etiological component affecting the development of chronic Chagas cardiopathy was 5.9% with an estimated annual average of 1.3%. There was no significant difference in the frequency of progressive disease between the sexes either in the chagasic or in the non-chagasic group. On the other hand, progression of heart disease occurred earlier among chagasic patients. Lethality caused by heart disease was 1.6% (2 cases) in the chagasic group and zero in the non-chagasic group during the period under survey. These morbidity and mortality rates were significantly lower than those found in endemic areas such as Virgem da Lapa and Pains-Iguatama in the State of Minas Gerais and can probably be attributed to the weaker pathogenic it of human infection by Trypanosoma cruzi in the Paraíba hinterland.

[Parasitemia in chronic chagasic patients evaluated using the index of infected Triatoma in xenodiagnosis]. / Parasitemia em pacientes chagásicos crônicos avaliada pelo índice de triatomíneos infectados no xenodiagnóstico.

As part of a pre-treatment study of chronic Chagas infections, the parasitemia of 206 patients (85 men and 121 women, aged 7 to 80 y) from Virgem da Lapa, Minas Gerais State Brazil, was evaluated by three xenodiagnoses per patient during a one year period. Each time, 40 3rd or 4th instar nymphs of Triatoma infestans were applied. The parasitemia was arbitrarily classified as: not detected (when all nymphs were negative), low (when the number of infected nymphs was less than 2%), medium (when it was higher than 2% and up to 7%) and high (when higher than 7%). The parasitemia was not detected in 105 (51%) of the patients, and was considered low in 55 (26.7%), medium in 27 (13.1%) and high in 19 (9.2%). There was no significant differences in levels of parasitemia in relation to sex or age, but the high parasitemia was more frequent among the patients with chagasic cardiomyopathy. Persistent parasitemia (all three xenodiagnoses positive) was observed in 100% of the patients with high parasitemia, in 22.2% with medium and in none with low parasitemia.

Novos parâmetros para ventilaçäo controlada em pós-operatório de cirurgia cardíaca em crianças / New parameters for the controlled ventilation in postoperative care of heart surgery in children

O propósito do presente estudo foi determinar parâmetros simples para uso em ventilaçäo pulmonar no pós-operatório de crianças submetidas a cirurgia cardíaca. Inicialmente os autores usaram a idade como parâmetro básico, mas os resultados aleatórios obtidos levaram ao seu abandono. Em uma segunda tentativa foi selecionado o peso corporal, e a partir deste foram estabelecidos o fluxo de admissäo de gases (FAG), o volume corrente (Vt), a freqüência respiratória (f), o tempo inspiratório (T) e o tempo expiratório (TE). As fórmulas utilizadas para o cálculo destas variáveis säo apresentadas. Os autores apresentam, também, uma tabela construída para uso com valores fixos da relaçäo inspiraçäo/expiraçäo (I:E::1:1,5), da complacência interna do aparelho (CI = 0,67 ml/cm H2O) e da pressäo inspiratória (PI = 15 cm H2O). O emprego desta tabela na ventilaçäo pulmonar com o ventilador Bourns BP 200 em 68 crianças resultou em 82,3% de acertos, considerada como acerto a obtençäo de uma P a CO2 de 4,8 kPa ñ 0,8 kPa (36mmHg ñ 6 mmHg)