Valores espirométricos en niños y adolescentes chilenos sanos / Spirometric values in healthy Chilean children and adolescents

Background: Spirometric flow and volume measurement are essential to evaluate patients with pulmonary disease. In Chile, several reference equations are used. Aim: To measure flow and expiratory volumes in healthy children and adolescents and compare their results with theoretical values according to Knudson, Quanjer, Gutierrez and NANHES III. Subjects and Methods: Spirometries were performed according to international standards in 1589 healthy children and adolescents aged 6 to 18 years (861 females) who lived in Santiago, Chile. Results: The obtained values for forced vital capacity, expiratory volume in one second, peak expiratory flow, were significantly higher than those calculated according to the above mentioned standards (p < 0.0001) with differences up to 18.7%. We constructed reference formulas for ages ranging from 6 to 18 years, separated by gender, using age, weight and height as independent variables. The latter had the greater influence on formula construction. Conclusions: The use of these new local formulas with allow the correct interpretation of spirometric results obtained in Chilean children and adolescents.

Post-mortem findings and piglet mortality in relation to strategic use of straw at farrowing.

Piglet survival is the outcome of complex interactions between the sow, the piglet and their environment. In order to facilitate nest-building and to provide a suitable environment for the newborn piglets, a strategic method to supply loose housed sows with large quantities of straw at farrowing has been developed by Swedish piglet-producing farmers. The objectives of this cohort study were to use post-mortem findings to assess the causes of death and to quantify the effect of a large quantity of straw provided before farrowing compared to limited small daily amounts on stillbirths, post-mortem findings in piglets dying within 5 days after birth and the pre-weaning mortality. On each of four commercial piglet-producing farms in South-West Sweden, one batch of sows was studied during two consecutive lactations. At inclusion, sows were randomly assigned to two treatment groups, and sows remaining in the batch during the next lactation switched treatment group. In the STRAW group (n=181 litters) sows were provided with 15-20 kg of chopped straw 2 days prior to the calculated date of farrowing. Sows in the CONTROL group (n=182 litters) received 0.5-1 kg of chopped straw on a daily basis plus about 2 kg for nest-building when the stockperson judged the sow to be about to farrow. After onset of farrowing, additionally 1-2 kg was given. Post-mortem examination was performed in all piglets that died within 5 days after birth (n=798). The three major post-mortem findings were starvation (34%) crushing by the sow (28%), and enteritis (24%). In conclusion, strategic use of large quantities of straw reduced the number of stillborn piglets per litter by 27% (p=0.007). Under the conditions studied, the pre-weaning mortality of liveborn piglets was not affected by treatment; however, the distribution of post-mortem findings differed with fewer piglets dying due to starvation and more due to crushing and enteritis in STRAW litters.

[Spirometric values in healthy Chilean children and adolescents]. / Valores espirométricos en niños y adolescentes chilenos sanos.

BACKGROUND: Spirometric flow and volume measurement are essential to evaluate patients with pulmonary disease. In Chile, several reference equations are used. AIM: To measure flow and expiratory volumes in healthy children and adolescents and compare their results with theoretical values according to Knudson, Quanjer, Gutierrez and NANHES III. SUBJECTS AND METHODS: Spirometries were performed according to international standards in 1589 healthy children and adolescents aged 6 to 18 years (861 females) who lived in Santiago, Chile. RESULTS: The obtained values for forced vital capacity, expiratory volume in one second, peak expiratory flow, were significantly higher than those calculated according to the above mentioned standards (p < 0.0001) with differences up to 18.7%. We constructed reference formulas for ages ranging from 6 to 18 years, separated by gender, using age, weight and height as independent variables. The latter had the greater influence on formula construction. CONCLUSIONS: The use of these new local formulas with allow the correct interpretation of spirometric results obtained in Chilean children and adolescents.

Large quantities of straw at farrowing prevents bruising and increases weight gain in piglets.

Two major welfare issues in current pig production are the lack of nesting material for farrowing sows and poor claw health in suckling piglets. Therefore, a strategic method to supply loose housed sows with large quantities of straw at farrowing has been developed by Swedish piglet-producing farmers. The objective of this cohort study was to estimate the effect of a large quantity of straw (15-20 kg) supplied before farrowing compared to limited daily amounts (0.5-1 kg) on bruising and growth performance in pre-weaning piglets. On each of four commercial piglet-producing farms in south-west Sweden, one batch of sows was studied during two consecutive lactations. At inclusion, sows were randomly assigned to two treatment groups, and sows remaining in the batch during the second lactation switched treatment group. In the STRAW group (n=181 litters) sows were provided with 15-20 kg of chopped straw 2 days prior to expected farrowing. Sows in the CONTROL group (n=182 litters) received 0.5-1 kg of chopped straw on a daily basis plus 2 kg for nest building when the stockperson judged the sow to be about to farrow. Piglets were individually weighed within 36 h after birth, at 3-7 days after birth and at weaning. On day 3-7, limbs and feet were clinically examined for the presence and location of lesions. In conclusion, the provision of 15-20 kg of straw 2 days prior to farrowing effectively prevents the piglets from developing skin abrasions (IRR=0.38) and soft heel/sole erosions (IRR=0.08-0.35). We also conclude that the strategic use of large quantities of straw has a positive effect on weight gain, increasing the expected mean body weight at weaning by 0.33 kg.

Prevalence of habitual snoring and associated neurocognitive consequences among Chilean school aged children.

OBJECTIVE: To assess the prevalence of habitual snoring and symptoms of sleep disordered breathing (SDB) and their association with neurocognitive consequences in school-aged children. METHODS: A population based cross-sectional study was carried out in a low income urban setting in Santiago, Chile. A parental SDB-questionnaire was adapted and applied to a community based sample of children aged 7-17 years. Hyperactive/inattentive behavior was assessed using the Conner's rating scale. School grades were obtained and the associations between questionnaire's results and risks for poor academic performance were investigated. RESULTS: Of 700 questionnaires sent; 523 (75%) returned correctly filled in. Mean age of the subjects was 11.0±2.5 years; 246 (47%) were boys. Prevalence of habitual snoring was 18%. The Conner's rating scale correlated significantly with the SDB-questionnaire's score (r(s)=0.47). Children with habitual snoring showed significantly lower (mean±standard deviation) school grades in Spanish language (5.6±1.2 vs. 5.4±0.9, p-value=0.04) and general average school grades (5.9±0.6 vs. 5.7±0.6, p-value=0.05). After adjustment for possible confounding factors, children with an abnormal SDB questionnaire score had significantly higher risk for poor academic performance in Spanish language, odds ratio (95% confidence interval): 1.82 (1.01-3.27) and physical education 1.85 (1.05-3.26). DISCUSSION: There was a high prevalence of habitual snoring and symptoms of SDB in this survey of Chilean children, being among the highest reported. The presence of habitual snoring and an abnormal SDB questionnaire were associated with poor academic performance and hyperactive behavior.

Scoring tail damage in pigs: an evaluation based on recordings at Swedish slaughterhouses.

BACKGROUND: There is increasing interest in recording tail damage in pigs at slaughter to identify problem farms for advisory purposes, but also for benchmarking within and between countries as part of systematic monitoring of animal welfare. However, it is difficult to draw conclusions when comparing prevalence's between studies and countries partly due to differences in management (e.g. differences in tail docking and enrichment routines) and partly due to differences in the definition of tail damage. METHODS: Tail damage and tail length was recorded for 15,068 pigs slaughtered during three and four consecutive days at two slaughterhouses in Sweden. Tail damage was visually scored according to a 6-point scale and tail length was both visually scored according to a 5-point scale and recorded as tail length in centimetres for pigs with injured or shortened tails. RESULTS: The total prevalence of injury or shortening of the tail was 7.0% and 7.2% in slaughterhouse A and B, respectively. When only considering pigs with half or less of the tail left, these percentages were 1.5% and 1.9%, which is in line with the prevalence estimated from the routine recordings at slaughter in Sweden. A higher percentage of males had injured and/or shortened tails, and males had more severely bitten tails than females. CONCLUSIONS: While the current method to record tail damage in Sweden was found to be reliable as a method to identify problem farms, it clearly underestimates the actual prevalence of tail damage. For monitoring and benchmarking purposes, both in Sweden and internationally, we propose that a three graded scale including both old and new tail damage would be more appropriate. The scale consists of one class for no tail damage, one for mild tail damage (injured or shortened tail with more than half of the tail remaining) and one for severe tail damage (half or less of the tail remaining).

Flexible fiberoptic bronchoscopy in children with heart diseases: a twelve years experience.

In children, cardiac diseases and respiratory disorders are tightly linked entities whose evaluation should be performed integrally. Flexible fiberoptic bronchoscopy (FB) presents a diagnostic and therapeutic role by assessing the airway anatomically, dynamically, and through the performance of several procedures. The present study describes our experience on FB assessment in children with congenital and acquired cardiac diseases, providing a characterization of the principal demographic and clinical features. Records of 72 patients under 14 years (mean age 21 months) with heart diseases, corresponding to 104 FB performed between January 1993 and October 2004 were reviewed. The principal cardiac diseases were left-to-right shunt (51.9%), followed by right-to-left shunt (17.3%) and miscellaneous cardiopathies (8.7%). The main indications for FB assessment were study of atelectasis (35%), stridor (14%), and pneumonia (14%). Airway malacias, as a group, were the commonest finding, represented mainly by left main bronchus malacia (24%). The second most common finding was stenosis by extrinsic compression, and among these, 75% corresponded to left main bronchus compression. Sixteen different types of clinically meaningful utilities were obtained. No mortality was reported and in only one procedure was there a major complication, which was easily managed. We concluded that FB is an important and safe diagnostic-therapeutic tool in the health care of neonates, infants, and children with a variety of cardiac diseases.

[Empyema and pleural effusion in children]. / Empiema y efusión pleural en niños.

INTRODUCTION: Pleural empyema (PE) is a serious complication of community-acquired pneumonia (CAP). OBJECTIVES: To describe the clinical profile of hospitalized patients with PE in the pediatric ward of the Catholic University Hospital between 2000-2005. PATIENTS AND METHODS: Retrospectively, all pediatric admission due to CAP and pleural effusion (86 children) were identified. In 59 (70%) children > 1 thoracocentesis were performed. We considered PE as the presence in the pleural effusion of pus, and/or a positive gram strain and/ or positive culture, and/or a pH < 7.10. Children with effusions not meeting any criteria were used as controls. RESULTS: Twenty four PE and 25 controls were identified, with a global mean age of 2.9 years (range: 8 months to 14.3 years); 78% were < 5 years, with a significant difference between PE and controls [1.6 vs 3.3 years (p = 0.01)]. The mean duration of symptoms in PE patients before admission was 7 days (range: 2-21), and the most frequent symptoms were fever (100%) and cough (96%). In 15/24 cases a microorganism was identified being Streptococcus pneumoniae (n = 9) the most common. In 48 patients management was conservative and in 4 surgical procedures were required. The mean duration of hospitalization was significantly higher in the PE group vs controls group: 15 (range: 5-38) vs 9 days (range 3-16) (p < 0.01). A chest tube was inserted in 83% of children with EP compared with 36% in the control group (p = 0.002). There were no difference in number of days of oxygen use [6 vs 4.5 (p = 0.36)] or number of chest tubes per child [3 vs 2.5 (p = 0.29)]. No deaths were reported. CONCLUSION: PE in children represented an acute respiratory event associated with more prolonged hospitalization especially at younger ages; the majority of cases did not require surgical intervention.

Corticoides inhalados / Inhaled corticosteroid

Durante muchas décadas, los corticoides inhalados han sido las drogas de elección para el manejo y control del asma crónica, tanto en niños como en adultos. Diversas guías y consensos de manejo (internacionales y nacionales) recomiendan su uso; sin embargo existe pocas revisiones publicadas en nuestro medio de sus aspectos mas básicos. En el presente artículo se revisan los mecanismos de acción y el rol del receptor para glucocorticoides intracitoplasmático, así como sus interacciones moleculares con otros receptores importantes para la expresión de genes que codifican para la síntesis de proteínas específicas pro-inflamatorias y anti-inflamatorias. Se revisan las equivalencias - en términos de dosis - y las principales diferencias entre los corticoides disponibles actualmente, para finalmente describir brevemente los efectos adversos más frecuentes descritos en niños.

Estudios polisomnográficos en niños / Polysomnographic study in children

La polisomnografía es un examen de gran utilidad en pediatría para el estudio de los niños roncadores con sospecha de Síndrome de Apnea-Hipopnea Obstructiva del Sueño (SAHOS). En el pasado se intentaba prevenir la aparición de secuelas cardiovasculares como el cor pulmonale, lo que se ha logrado satisfactoriamente al identificar y tratar a los pacientes claramente sintomáticos. La literatura internacional nos ha mostrado los últimos años la gran cantidad de alteraciones neurocognitivas asociadas al ronquido y SAHOS. A su vez existe una clara relación entre el SAHOS del adulto con la hipertensión arterial y patología cardiovascular.

Muerte súbita del lactante / Sudden infant death

La muerte súbita (MS) del lactante es una de las condiciones más trágicas en la vida de una familia, representando una de las causas mas frecuentes de muerte infantil en los países desarrollados. Pese a todos los esfuerzo se desconoce muchos aspectos fisiopatológicos. Por otra parte, si bien existe una relación con ALTE, ésta aún no es fácil de entender. En ésta breve revisión se analizan algunos datos recientes en la literatura acerca de fisiopatología, factores de riesgo, manejo de MS y las recomendaciones y consensos para prevenir la MS.

Craniofacial and dentofacial development in pigs fed soft and hard diets.

INTRODUCTION: Several authors have found a correlation between reduced chewing activity and malocclusion. In animal experiments, it has been possible to correlate a diet of low chewing resistance to narrower arches, which predispose the subject to crowding and irregular teeth. METHODS: In this study, 17 pigs were weaned at 5 weeks of age and divided into 2 groups according to diet and housing. The soft-diet, indoor group was housed in conventional pens, and the animals were fed aliquots of barley and oats with soya and a mineral-vitamin premix added. The food was mixed with water at a dry matter content of about 25%. The hard-diet, outdoor group was kept outdoors; the pigs were fed solid food and also ate organic matter in the soil. All pigs were killed at 22 months of age. The skulls were dissected, and transverse and sagittal craniofacial and dentofacial dimensions were measured. RESULTS: Chewing hard food caused considerable occlusal and approximal attrition in the experimental animals. The dental arches were shorter due to this attrition and to mesial migration of the molars and premolars. The approximal attrition also reduced the tendency for crowding and rotation of the teeth. Posterior crossbite was more common among the hard-chewing animals. CONCLUSIONS: The increase in arch width in the hard-diet animals reported in the literature was not duplicated in this study. On the contrary, the soft-diet pigs had significantly wider arches than the hard-diet animals. This was most pronounced in the premolar region and could be the result of an atypical tongue habit, caused by the nonphysiologic feeding of the pigs. The soft-diet pigs also had a greater tendency to postnormal occlusion, especially in the canine region.

[Non-typable Haemophilus influenzae severe pneumonia in an infant: case report]. / Neumonía grave causada por Haemophilus influenzae no tipificable en un lactante: reporte de un caso.

Haemophilus influenzae b (Hib) disease used to be a frequent cause of pneumonia in children. After the widespread use of Hib conjugate vaccines, non-b H. influenzae have become an important cause of pneumonia. We present the case of an infant with severe pneumonia with empyema and bacteremia after he had completed the Hib vaccination schedule. Non typable H. influenzae was recovered from blood and pleural effusion cultures. We review the literature about this unusual clinical presentation in our community and alert about the possible emergence of non typable H. influenzae as a frequent cause of community-acquired pneumonia in children.

Airway anomalies in children with Down syndrome: endoscopic findings.

Down syndrome (DS) is the most common chromosomal anomaly in humans. Numerous congenital malformations associated with DS have been described. However, there are insufficient data available about airway anomalies. Our objective was to characterize the clinical presentation, frequency, and type of airway anomalies in a population of patients with DS. A retrospective evaluation of flexible bronchoscopies performed in 24 DS patients due to significant respiratory morbidity was compared to the findings in 324 non-DS patients during the same time period. The procedure was carried out under sedation, using an Olympus BF3C20 bronchoscope. The main indications for the procedure were atelectasis of the right upper lobe (12/24) and stridor (7/24). The most common associated conditions were congenital heart disease (12/24) and reactive airways disease (12/24). The most important endoscopic findings were: laryngomalacia (12/24), tracheomalacia (8/24), tracheal bronchus (5/24), and bronchomalacia (5/24). Only six patients had a normal examination. Multiple airway anomalies (>/=2) were a common finding in this series. We conclude that patients with DS and respiratory symptoms have a high incidence of airway anomalies compared to non-DS patients. The clinician should have a high index of suspicion for airway anomalies in DS patients with respiratory symptoms.

Clinical characteristics of children with tracheobronchial anomalies.

Tracheobronchial anomalies (TBA) originate between the third and sixteenth week of gestation, and they primarily affect the main bronchi. The reported incidence varies between 1-3% of pediatric endoscopic studies. The objective of our review was to describe the clinical characteristics of patients with TBA diagnosed by flexible bronchoscopy (FB). During the period from March 1993-May 2001, we performed 580 FB at the Pediatric Services of the Catholic University Hospital. During this study period, 52 patients (9.65%) had a TBA (32 males, or 61.5%), with a mean age of 21.2 months (range, 7 days to 6 years). In 39 cases (75%), the diagnosis was made under age 2 years. Thirty-six patients with symptoms related to TBA were symptomatic (70%), and in 16 cases (30%) the TBA was an accidental finding during FB. The main clinical manifestations were recurrent atelectasis of the right upper lobe (RUL), recurrent pneumonia, or congenital stridor. Most of the TBA were localized at the RUL bronchus (47%) and were characterized by an anomaly at its origin, either agenesis or a supernumerary bronchus. Also, we found patients with tracheal bronchus and congenital tracheal stenosis. In 6 patients (12%), we had more than one TBA, the most frequent being the association between RUL and RML anomalies. In 12 cases we found another congenital airway anomaly, mainly laryngomalacia. Patients had associated diseases, such as genetic disorders in 16 cases (particularly Down syndrome), and congenital cardiopathies. In summary, in our clinical experience, TBA are more frequent than previously reported. The majority of young patients have symptoms or signs, and most are localized to the RUL. We found patients with more than one TBA, laryngomalacia associated with TBA, and at a high frequency related to Down syndrome.