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OBJECTIVE: To evaluate empyema formation in rats through the injection of two bacteria (Pasteurella multocida and Staphylococcus aureus), using a simple, easy-to-use surgical technique. METHODS: Twenty four anesthetized Wistar white rats, 250-300g in weight, submitted to right anterior thoracotomy, muscular retraction and injection of a 0.2ml solution into pleural space according the following scheme: Group I (n=12): injection of 10(10) Pasteurella multocida cultured in brain heart infusion broth. Group II (n=8): injection of 10(10) Staphylococcus aureus cultured in brain heart infusion broth. Group III (n=4): injection of bacterium-free brain heart infusion (control). The rats were sacrificed after seven days, and pleural reaction was assessed by macroscopy. Mortality, and intrathoracic liquid volume were evaluated, and bacteriological tests were also performed. RESULTS: Seven rats died within the first 48 hours in Group I (Pasteurella multocida); five completed the experiment, but none of them presented empyema. Only one animal died within the first 24 hours in Group II (Staphylococcus aureus); seven (88%) presented empyema at the time of sacrifice. All animals survived in Group III (control), without empyema or thoracic abnormalities. Pleural inoculation of Staphylococcus aureus (Group II) was significantly associated with empyema formation (P<0.001). In this group, the amount of pleural liquid ranged from 0.9 to 3.9ml. CONCLUSION: It is possible to induce empyema in rats through Staphylococcus aureus pleural injection by a simple surgical technique. Differently from other experiments, the pleural injection of Pasteurella multocida did not provoke empyema in rats.
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OBJECTIVE: To alert about the great variability of clinical and radiological features of Mycoplasma pneumoniae pneumonia in pediatric patients. Although it has been referred as a prevalent entity in children, its diagnosis is, many times, retarded due to the lack of a pattern that can really be considered classic.METHODS: The authors present 5 cases of mycoplasma pneumonia in children. Diagnostic difficulties, clinical features, radiological findings and evolution after treatment are discussed. The cases have their significant peculiarities confronted with the findings of medical literature of the last two decades, obtained through a bibliographic research in Medline about the subject.RESULTS: All the patients were between 6 and 9 years old, characteristically the most prevalent age group for this infection. In none of the cases the possibility of mycoplasma infection was considered at first. Clinical hypothesis like sinusal aspirative pneumonia, tuberculosis, and asthma were initially considered, but later on discarded. Except for one, all the other patients referred previous treatment with antibiotics. The initial radiological findings were different among the cases: bronchopneumonic consolidations, pleural effusion, perihilar adenopathy with interstitial infiltrated, and atelectasic areas. After the institution of specific therapy, clinical and radiological evolution was favorable in all cases.CONCLUSIONS: Mycoplasma pneumoniae pneumonia has a great sort of clinical presentations. In the same way the complementary radiological investigation may also demonstrate different patterns of presentation. Due to its great variability, mycoplasma is not commonly considered as the first diagnosis, even though it is a prevalent disease at pediatric age. This may lead to a delay in the diagnosis and institution of an appropriate treatment.
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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.
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OBJECTIVE: To present current concepts on diagnosis and treatment of upper airway obstruction, mainly related to differential diagnosis between acute viral laryngotracheobronchitis and epiglottitis.METHODS: Bibliographic review covering the last ten years, using both Medline system and direct research. The most relevant articles published about the subject were selected.RESULTS: Viral laryngotracheobronchitis is an acute self-limited disease of the upper airway in a child, clinically characterized by barking cough, stridor, hoarse voice, and upper respiratory symptoms. The disease is diagnosed by clinical signs and symptoms. Rarely, if no immediate airway management is needed, radiography of the neck may help to exclude other entities that cause laryngeal obstruction. In contrast to viral laryngotracheobronchitis, epiglottitis is characterized by inflammation of the supraglottic tissues and is caused mainly by Haemophilus influenzae type b. A previously healthy child suddenly develops a sore throat and fever. Within hours after the onset of symptoms the patient looks toxic, swallowing is painful and breathing is difficult. Drooling and cervical hyperextension are frequently present. Lateral neck radiograph is rarely required to the diagnosis and may delay appropriate management of the airway. Moderate viral laryngotracheobronchitis with stridor at rest and retractions should be treated with steroids (systemic or nebulized) and nebulized epinephrine. Severe viral laryngotracheobronchitis should be treated aggressively while arregements are made for endotracheal intubation. The diagnosis of epiglottitis requires immediate endotracheal intubation in the appropriate unit (emergency department, intensive care unit or surgical unit) and antimicrobial therapy. Alternatively at some medical centers children with severe upper airway obstruction have been treated with a mixture of helium and oxygen (70 to 80% concentration of helium) instead of room air or pure oxygen to avoid intubation.CONCLUSIONS: There are different levels of care for patients with upper airway obstruction, depending on their clinical presentation. The clinical manifestations of viral laryngotracheobronchitis may be confused with the presentation of epiglottitis. Despite this observation we believe that differential diagnosis between viral laryngotracheobronchitis and epiglottitis rests on clinical grounds.
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OBJECTIVES: The authors review the current literature on acute viral bronchiolitis discussing the points still subject to controversy in regard to its treatment. At the same time, a personal point of view on the management of this disorder based on the authors experience is also expressed.METHODS: The main published papers from the last twenty years were selected from a Medline database search.RESULTS: Acute viral bronchiolitis is an acute viral illness of the lower respiratory tract occuring most frequently during the first year of life. In spite of its important prevalence and the relative risk that this disorder may pose to pediatric patients there is still a lot of controversy in regard to its treatment. However, it seems of paramount importance to mainten an adequate hidration, to prevent cross infection and to offer supplementary oxygen. There are many doubts as to the role of bronchodilators and antivirals such as ribavirin. There are new hopes with the introduction of specific immunoglobulin, mostly as a prophylactic role in respiratory syncycial virus infection in at risk populations. Steroids seem to have no place in the treatment at least in the acute stages of the disease. CONCLUSIONS: Acute viral bronchiolitis is still a disorder which lacks a specific treatment. The routine treatment has little changed for the last 30 years and there is controversy in regard to its management in the different clinical centers.
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OBJECTIVE: The authors describe their experience with theuse of intravenous Beta2 adrenergic (IV terbutaline) in patientsadmitted to a PICU with severe lower airway obstruction. PATIENTS AND METHODS: A retrospective study of all admissions to a PICU was conducted in Santo Antonio Hospital in Porto Alegre (Brazil) during the winter of 1995. The files ofall the patients that were treated with intravenous Beta2 adrenergicas a bronchodilator were selected. The analysis included lengthof use, initial doses, maximal doses, associated phenomena,arterial blood gases and plasma level of potassium. RESULTS: During the three months of study 367 patients wereadmitted to the PICU and 38 (10.3%) used IV terbutaline. Thisgroup of patients had a mean age of 13.8-/+12.2 months old andused IV terbutaline for a mean length of 7.24-/+3.6 days. Theinitial rate of infusion was 0.55-/+0.25 mcg/kg/min with a meantherapeutic dose of 2.45-/+1.18 mcg/kg/min. Twelve patients(31.5%) had increase in their heart rate (over 180 bpm) thatprevented increases in the infusion rate. However this was atemporary effect. The patients under 12 months of age startedwith low infusion rates (0.45-/+0.22 mcg/kg/min), when comparedto children over 1 year old (0.57-/+0.3 mcg/kg/min), p <0.01. No patient developed pathologic heart rate attributed to the drug. The serum levels of potassium decreased significantly (p <0.01) only in the group of patients under 1 year (4.1-/+0.7 to 3.47-/+0.52 mEq/L), but this difference had no clinical relevance. COMMENTS: In view of these results the authors showed that the infusion of IV terbutaline in children is safe and presents alow risk if the criteria of administration and monitoring are followed. In this manner, IV terbutaline is an excellent therapeuticoption for children with severe lower airway obstruction andno response to the conventional treatment.
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It is an on-going practice in the pediatric ICUs to obtain and to maintain a working artificial airway. Nevertheless this procedure bears not infrequent risks of accidental extubation (AE) which ranges in several services from 0.9 to 3.3 for each 100 days of intubation. The risk factors that are involved in AE are related to: sedation level, age-group, intubation path, and others. The purpose of the authors in this article was to observe the incidence of AE in their service and to compare the relative risk in the rate of AE among orotracheal and nasotracheal intubation population. A prospective study was taken during six months, in which every patients with artificial airway admitted at the PICU of the Santo Antonio Hospital in Porto Alegre (Brazil) was included except those with tracheostomy. The total number of cases were 673 patients-day with artificial airway, with an average of 3.7 patients with tracheal tube per day. In the period there were 18 AE, with a rate of 2.7 AE/ 100 days. The incidence rate of AE in the orotracheal group was 3.1% and 1.6% in the nasotracheal group with no statistically significant difference (p=0.6). The authors concluded that the pathway of intubation in their study does not carry any additional risk in the incidence of accidental extubation.
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The authors discuss a case of a two-years-old girl, who had a unilateral previous enucleated retinoblastoma, that died with a suprasellar mass and distant metastasis.
