[Pneumonia complicated with empyema in children, to operate or not? Risk factors for surgery and review of the literature]. / Neumonía complicada con empiema en niños, operar o no operar? Factores de riesgo para cirugía y revisión de la literatura.

The precise indication for surgery for pleural empyema is still a controversy. With the aim of identifying the risk factors associated with surgery in pediatric patients with empyema post-pneumonia, a retrospective case control study was performed. From 1992 to 1996, 18 children underwent surgery (cases) and 12 did not (controls). The analyzed variables were those mentioned in the literature as risk factors. More than 25 days of evolution, more than three antibiotic schemes, fever, empyema organizing phase, two or more chest tubes lasting more than nine days, multiple loculations, trapped lung and paquipleura were associated with thoracostomy and decortication (p < 0.05). We conclude that a pediatric patient with a late referral to the hospital, empyema organizing phase, and multiple loculations with large purulent collections no longer susceptible to drainage and complications that impair lung expansion will probably require major surgery.

[Characteristics of medical care related to autopsy authorization in a pediatric hospital]. / Características de la atención médica relacionadas con la autorización de autopsias en un hospital pediátrico.

OBJECTIVE: To identify some differences of patients and medical characteristics related to autopsy authorization. DESIGN: Observational, cross-sectional study. SETTING: Third-level medical care in a pediatric hospital. METHODS: A specific mortality questionnaire was analyzed by members of the mortality staff, because they reviewed deaths which occurred between January 1994 and December 1995. Descriptive statistic and non-parametric tests (X2) were calculated to analyze data. RESULTS: A total of 408 deaths were evaluated, in which 116 autopsies were done (28.4%). Children less than 18 months of age had the highest frequencies of autopsies (33.3%-30.7%). The patients referred by other units and the autopsy application done by a medical resident, had the highest frequencies of acceptance (32.5%, 35.3%, p < 0.05). The detection of diagnostic and therapeutic problems were related with high frequencies of autopsies (37.7%, 36% p < 0.05). CONCLUSIONS: The results show us that some medical care factors are related to higher frequencies of autopsies. It is important to consider them in order to increase the capacity of teaching that a postmortem study has.

[Continuous spectrophotometry as a method to study pulmonary edema in isolated canine pulmonary lobe]. / Espectrofotometría continua como método para el estudio del edema pulmonar en una preparación de lóbulo pulmonar canino aislado.

The aim of this paper is to introduce the spectrophotometric method to the study of pulmonary edema in isolated ex-vivo canine pulmonary lobe preparation. This spectrophotometric method is based on the on-line measure of light transmission in a column of blood, that is proportional to hematocrit. A second light is used to follow Evans blue dyed proteins. With this method we were able to measure the amount of edema in 10 isolated canine lobes. Both the filtration and reflection coefficient of the membrane as well as the characteristics of the filtrate could be calculated. The filtration coefficient was 0.6 +/- 0.4 ml/min (1.3 +/- 0.9 ml/min/100 g pulmonary, tissue) at maximum capillary pressure and the reflection coefficient was 0.53 +/- 0.07. With the spectrophotometric method we have the capability to study different aspects of lung edema formation. This method has the advantage of being exact and independent from pressure and volume induced vascular changes. It also allows the measurement of solute transport.

[Severe respiratory failure secondary to vascular ring. Report of 2 cases]. / Insuficiencia respiratoria grave secundaria a anillo vascular. Informe de dos casos.

Vascular compression of the airways is an infrequent situation that can be masked by inespecific respiratory symptoms. We present two cases with severe respiratory distress, that needed assisted mechanical ventilation in patients with overdistended lungs which improved when the endotracheal cannula was shifted near the carina. The chest radiograph showed hyperinflation of the lungs; an identation was demonstrated in the esophagogram and the endoscopy demostrated extrinsic esophagical compression. The angiogram documented double aortic arch in the first case and aberrant subclavia artery in the second. Vascular section and liberation of trachea and esophagus were performed with good outcome. The decrease of thoracic overdistention when the cannula was placed in the lower part of the trachea gave the clue to the diagnosis of vascular ring. A high index of suspicion is necessary for an early diagnosis.

[Vascular conductance and critical closing pressure in the isolated canine lung in situ. Its natural history]. / La conductancia vascular y la presión crítica de cierre en el lóbulo canino aislado in situ. Su historia natural.

The vascular pressure-flow relationship (P-QL) in West's zone II condition were studied in isolated, in situ, canine, left lower lobe (ISLL) in order to characterize the total resistance in the pulmonary vascular bed (Rp), the normal values for pulmonary vascular conductance (Cv) and for critical closing pressure (PLc). After the basal parameters were obtained, measurements of Cv and PLc were done every 30' in order to know the natural history (NH) of this canine ISLL preparation. The P-QL relationship of the pulmonary vasculature of the ISLL preparation, perfused under classical zone II conditions, can be characterized by a rectilinear segment at high flow, a curvilinear segment at low flow and a pulmonary arterial pressure that exceeds alveolar (PA) pressure at zero flow. This demonstrates the existence of critical closing pressure (PLc) in the pulmonary vascular bed. The mean control Cv and PLc were 38.5 +/- 14 (ml. min)/mmHg and 7.9 +/- 2.2 mmHg respectively; those parameters did not change through the observation of the experiment. PLc was found to be independent of bronchial flow and it was not related to PA when the values for this pressure were less than 5 cm H20. On the contrary, higher levels of PA pressure were significantly related to PLc (r = 0.94, p less than 0.05). We conclude that in this model of ISLL in West's zone II condition it is possible to study the two components of Rp, one given by vessels that determine changes in flow resistance and for the other vessels disclosing critical closure. The values of these components remained stable over 180' of observation.

Diagnosis of lactose intolerance through the quantification of hydrogen in exhaled air.

Considerations are made on diarrhea secondary to intestinal malabsorption of carbohydrates and on the diagnostic means available in our environment, among which are the reactive strip, the clinitest tablet, tolerance curves and research of intestinal enzymes. The quantification of exhaled hydrogen is mentioned as a diagnostic method, used by several other authors, and a review of the literature on the subject is made. Considerations are made on a hydrogen quantification in the breath of patients with a transitory lactose intolerance. 16 patients were studied, 15 of whom showed an increase in the exhaled H2. 32 children with diarrhea, free from lactose intolerance, were studied. The method used did not show a significant increase in the exhaled hydrogen. 27 patients showed no H2 in their breath. In 4 there was elimination of H2 (false positives). 17 diarrhea-free children were studied. A significant difference was found when comparing the children with diarrhea and lactose intolerance to the other two groups who were free from lactose-intolerance. It is considered that this method can be useful in the diagnosis of intolerance to lactose and other sugars.