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S S Barreto

Publications and source records attributed to S S Barreto.

6 recordsLinked to original sources
PubMed1998

[Respiratory failure in the child]

OBJECTIVE: To describe the main physiopathologic mechanism of the respiratory failure in the child, as well as to discuss some aspects of the differential diagnosis and treatment. SOURCE OF DATA: The main national and international textbooks and articles about respiratory failure in the child were used as sources of data for this research. RESULTS: Respiratory failure is defined as the incapacity to maintain a paO(2) over 50 mmHg associated or not to a paCO(2) over 50 mmHg in children breathing ambient air at sea level. This failure may be classified as hypoxemic or hypercapnic, or even as acute or chronic. The main alterations may be hypoventilation, ventilation perfusion mismatch and diffusion defect. It may be secondary to a central origin, upper or lower airway compromise, parenchyma disease, or due to pleural or thorax wall affection. The hypoxemia evaluation may be done by hemoglobin saturation, alveolar capillary gradient of oxygen (D[A-a]O(2)) or by the paO(2) / FiO(2) index. COMMENTS: The knowledge of the physiopathologic mechanisms that cause respiratory failure in the child is important to define the more efficient therapeutic strategy for each cause.

Journal Article↗
PubMed1993

Reduction of lung diffusion for carbon monoxide in patients with lung carcinoma.

A retrospective study to investigate the prevalence and severity of impairment of the lung diffusing capacity for carbon monoxide (DCO) in patients with lung carcinoma was done using a case-control matched design. A group of 70 patients with the histologic diagnosis of lung carcinoma was matched on a one-to-one basis with a group of patients with chronic bronchitis and/or pulmonary emphysema (COPD); the matching was done based on the FEV1 within 10 percent of each other for all pairs. The groups of lung carcinoma and COPD had similar history of smoking consumption and pulmonary function, except that the Dco was reduced in the carcinoma group (mean +/- SD: 56.4 +/- 12.8 percent of predicted) compared with the control group (64.4 +/- 20.1 percent of predicted; p = 0.0027). Among the carcinoma group, only one patient had a Dco above 75 percent of the predicted value, while in the control group, 22 patients had a Dco above 75 percent of predicted values. It appears that Dco is more frequently reduced in patients with lung carcinoma than in a group of patients with similar FEV1 and smoking history who have chronic bronchitis and/or emphysema but had no evidence of lung carcinoma. We speculate that the reduction of Dco in patients with lung carcinoma could be due to the concurrent presence of pulmonary emphysema.

Aged↗
PubMedDate not supplied

[Randomized clinical trial of intravenous magnesium sulfate versus salbutamol in early management of severe acute asthma in children]

OBJECTIVE: To study the efficacy of intravenous magnesium sulfate and intravenous salbutamol in the treatment of severe asthma in children. METHODS: Randomized, double-blind, placebo-controlled clinical trial, including children above 2 years of age with severe acute asthma admitted to the observation ward of the Pediatric Intensive Care Unit of Hospital São Lucas. All patients received conventional treatment (oxygen, corticoids, beta-adrenergics) on admission, and later received one of the following solutions: a) IVMg (50 mg/kg); b) intravenous salbutamol (1 micro g/kg); c) saline solution. Clinical assessments, electrolyte concentration, and arterial blood gas analyses were recorded before intravenous infusion and one hour after that. RESULTS: Fifty patients participated in this study (of whom 53% were females, mean age = 4.5 years). There were no significant differences among the three groups. The group that received IVMg presented lower blood pressure during administration, which reached normal levels one hour afterwards, along with an increase in serum magnesium (P<0,001) and serum pH, and reduction of PaCO(2). The group that received intravenous salbutamol had lower respiratory rate (P=0.05) and higher blood pressure (P=0.01), and one hour after administration, these patients showed decreased respiratory rate (P=0.02); lower levels of serum potassium (P=0.009); higher pH, and reduced PaCO(2). This group required fewer nebulizations (P=0.009), fewer nebulizations per day (P<0.001) and less oxygen therapy than the IVMg and placebo groups. Acidosis was more persistent (P<0.01) in the placebo group. No difference as to the length of hospital stay was observed in any of the three groups. Artificial ventilation was necessary in 10% of the patients. CONCLUSIONS: The early intravenous administration of magnesium sulfate, especially salbutamol, achieved a rapid clinical response with excellent prognosis and no significant side effects.

Journal Article↗
PubMedDate not supplied

[The use of helium-oxygen mixture in the ventilation study of children with chronic obstructive lung disease]

OBJECTIVE: To study the distribution of Tc-99m DTPA radioaerosol when heliox or oxygen are used in the nebulization of children and adolescents with chronic obstructive pulmonary disease during pulmonary ventilation scintigraphy. MATERIAL AND METHODS: Clinical randomized and controlled trial. Patients with chronic obstructive pulmonary disease (5 to 18 years old) who required pulmonary scintigraphy between March 1996 and September 1998 were included. Obstruction of the lower airway was measured by spirometry. Patients were randomized into two groups according to the gas used for nebulization during scintigraphy: heliox (80% helium and 20% oxygen) or oxygen. Scintigraphy studies were expressed as slope of the cumulative pulmonary radioactivity uptake curve and as the maximal cumulative radioactivity in the lung. The mean diameter of the Tc-99m DTPA particles generated by heliox and oxygen was measured by laser diffraction. RESULTS: Ten patients were allocated in each group. There were no statistical differences (P>0.05) in terms of gender, main diagnosis, signs of malnutrition, mean values of weight, height, body area, or spirometry results. The mean slope in the heliox group (5,039-/+1,652) was significantly different (P=0.018) from the mean slope of the oxygen group (3,410-/+1,100). The mean slope of patients with severe airflow obstruction in the heliox group was statically different (P=0.017) from the mean slope of patients with airflow obstruction in the oxygen group. In both groups, patients without evidence of airflow obstruction were similar in terms of mean slopes (P=0.507) and mean cumulative radiation in the lung (P=0.507). The mean diameter of heliox-generated Tc-99m DTPA particles was 2.13 m (-/+0.62). This was statistically different (P=0.004) from the mean diameter of oxygen-generated particles (0.88-/+0.99 m). CONCLUSIONS: Nebulization with heliox was more efficacious than nebulization with oxygen for distribution and dispersion of Tc-99m DTPA radioaerosol in the lungs of children and adolescents with chronic obstructive pulmonary disease submitted to ventilation scintigraphy. The benefits of heliox over oxygen are more evident in the presence of lower airway obstruction. Without airway obstruction, we did not observe any difference in the distribution and dispersion of radioaerosol in the lungs. Although the mean diameter of the Tc-99m DTPA particles generated by heliox and oxygen was significantly different, the particles generated by both gases were still within the recommended range (between 1 and 5 m). Therefore, this difference does not account for the effects of heliox observed in this study.

Journal Article↗
PubMedDate not supplied

[Factors related to severe acute asthma in childhood - epidemiologic and clinical aspects].

OBJECTIVE: To study the epidemiologic and clinical factors related to severe acute asthma in patients hospitalized in pediatric intensive care unit (PICU). STUDY PROFILE: Prospective, epidemiologic. All admissions were observed. PATIENTS AND METHODS: All children with severe asthma admitted to PICU-HSL-PUCRS between January, 1994, and December, 1994. Their parents were asked to answer a questionnaire about clinical history and precipitating factors of bronchospasm. Clinical evolution was observed in each patient. RESULTS: 31 children were admitted on 42 occasions to the PICU for the treatment of severe asthma (7.3% of all admissions). The male: female ratio was 1.2:1.0 and the age mean was 25 months. Respiratory viral infections were the main precipitating factor of asthma attacks (74%). Family history of asthma, atopy or tabagism were observed in 97% of the cases. A longer hospitalization period was associated with less than 1 year age (p=0.0005), family history of tabagism (OR= 2.3) and occurrence of pneumonitis (p= 0.03). The long stay in PICU was associated with previous PICU admission (p=0.03), family history of tabagism (OR=2.0) and occurrence of pneumonitis (p=0.02). The main complication observed, especially in patients under 1 year receiving public health care, was pneumonitis, that was diagnosed in 42% of these children. Patients assisted by a private doctor had a shorter hospitalization period and less pneumonitis complication. Mechanical ventilation was necessary in 10% of these patients. There was no death in our series. CONCLUSIONS: The incidence of severe acute asthma, associated with long staying in PICU and hospitalization, is related to low age (under 1 year), previous hospitalization due to bronchospasm, family history of asthma, atopy or tabagism, and ineffective medical care. These factors seem related to frequent crises causing more hospitalization indications. These children frequently present pneumonitis during their clinical evolution. Early and aggressive management in general benefit the clinical course of severe acute asthma. The mortality ratio for children with acute asthma who need PICU admissions is small.

English Abstract↗