Héctor Navarro M

Prevalencia de síntomas de rinitis alérgica y su relación con factores de riesgo en escolares de Santiago, Chile

Background: The prevalence of asthma and allergic rhinitis experienced a steady increase in the last years, probably associated to changes in lifestyles. Aim: To assess the prevalence of allergic rhinitis, to evaluate changes over time (1994-2000), and to describe risk factors. Material and Methods: The International Study of Asthma and Allergies in Childhood (ISAAC) core questionnaire, with questions added about socioeconomic status (SES), was applied to 4594 children between 6-7 years old and 13-14 years old during october-december 2000. Attendance to public or private schools was also used a SES proxy. The results were compared with those of a similar survey in 5281 children, performed in 1994. Rhinitis symptoms (ever) (SR), rhinitis symptoms within last 12 months (SR12) and medical diagnosis of rhinitis (DR) were assessed. Results: There was a significant increase in the prevalence of SR, SR 12 and DR in both age groups in 2000, compared to 1994. SR older children showed a higher prevalence of SR compared with the youngest group (p=0.003). No age differences were observed in the prevalence of SR12 and DR. Both SR and SR12 were more prevalent at schools of medium and low-medium SES (p=0.003 and p=0.002 respectively). DR was significantly more prevalent among children of high SES. A better mother educational level was associated to higher prevalence of SR and SR12 (p=0.03 and p=0.04). Father educational level was associated to DR (p=0.007). The prevalence of SR12 was higher in households with carpets (p=0.017). The prevalence of DR was higher in houses with smokers (p=0.03) and gas heating (p=0.005). None of the three variables were related to gender. Conclusions: The prevalence of SR, SR12 and DR increased significantly in a short time period (6 years). Our results support a positive association between DR and high SES (Rev Med Chile 2006; 134: 456-64).

Identificación de mutaciones en el gen CFTR en pacientes chilenos con fibrosis quística

Background: Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the CFTR gene, that codes for a chloride channel located in the apical surface of epithelial cells. The main role of this protein is the regulation of chloride transport, and secondarily, of sodium and water to the extracellular space. More than 900 gene mutations have been described, and their relative frequency in different populations depends on their ethnic origin. Aim: To report the findings of Chilean patients with cystic fibrosis, in whom the presence of 20 common mutations was analyzed. Patients and methods: Fifty seven patients with established diagnosis or suspicion of CF were studied. The simultaneous identification of 20 mutations and the normal DF508 allele was done using polymerase chain reactions with a commercial assay. Results: Eight mutations were found. Fifty patients fulfilled diagnostic criteria proposed by the Consensus Panel of the CF Foundation and 66% of alleles were identified in this group. ∆F508 mutation was found in 45%. We did not identify mutations in any of the remaining 7 patients. Conclusions: Our results suggest that the majority of undetected mutations are associated with atypical phenotypes or that some patients in this series could have other diseases. We recommend to include mutation analysis in the evaluation of Chilean patients with CF. It is useful to establish prognosis and genetic counselling (Rev Med Chile 2001; 129: 841-7).

Influencia del nivel socioeconómico (NSE) en el asma bronquial y cambios en su prevalencia en población escolar en un periodo de 6 años

Antecedentes: La prevalencia de asma se encuentra mundialmente en aumento, especialmente en paises en desarrollo. Objetivos: Determinar la prevalencia de asma en escolares de Santiago, estudiando la influencia del nivel socioeconomico (NSE) y describir su evolucion en un periodo de 6 anos. Material y metodos: Estudio transversal en poblacion escolar de la Region Metropolitana. Se encuesto a 4.561 escolares de 6-7 y 13-14 anos provenientes de establecimientos publicos de la comuna de Santiago y de colegios particulares pagados ubicados en el sector oriente de la ciudad. Las variables estudiadas fueron diagnostico de asma (DA), sibilancias en los ultimos 12 meses (SIB12) y frecuencia de episodios de sibilancias (FES). Mediante modelos de regresion se calcularon odds ratios para la ocurrencia de estas variables segun la exposicion a diversas variables independientes. Resultados: La prevalencia de DA en el grupo completo de escolares fue mayor en escolares varones respecto de mujeres (13,2% vs . 10,8%) (p = 0,016), siendo estadisticamente mayor en escolares de 13-14 anos respecto del grupo de 6-7 anos (13,8%: vs .10,1%). (p -4 ). Se encontro una asociacion inversa significativa entre NSE y SIB12. Un mayor nivel de educacion materna se asocio a menor prevalencia de SIB12 en ambos grupos de edad y de FES en ninos de 6-7 anos. Un mayor nivel de instruccion paterna determino un incremento en DA entre los mas pequenos. Incrementos significativos en la prevalencia de SIB12 y FES fueron observados entre 1994 y 2000 unicamente en escolares de 6-7 anos de Santiago Centro. Conclusion: Se encontro asociacion significativa entre NSE y el diagnostico y sintomatologia del asma en escolares de Santiago, asi como un incremento de su prevalencia y severidad en el grupo de 6-7 anos en el periodo 1994–2000.

Derrame pleural y empiema complicado en niños: Evolución y factores pronósticos

Background: Complicated pleural empyema has a torpid and longer clinical evolution, requiring in some patients surgical management. The predictive factors for surgical treatment are not well known. Aim: To search for clinical, laboratory or radiological predictors for the requirement of surgical treatment in pediatric patients with empyema. Patients and methods: A retrospective review of the charts of 108 patients hospitalized for pneumonia plus pleural effusion at the Pediatric Service of the Catholic University Hospital between January 1985 and July 2000. Results: Eighty one patients had complete radiological evaluation and pleural fluid biochemical analysis. Forty nine (60%) fulfilled the criteria for empyema and 32 (40%) for an exudate. Thirteen patients with empyema required surgery and 36 were treated medically. The mean age was 3 years (range 9 months-6 years) for the surgically treated and 4 years (range 12 months-14 years) for the non-surgical group. The male/female ratio was 5:1 in the surgical group and 1:1 for the non-surgical group. Pleural fluid cultures were positive in 21 of 79 patients. Streptococcus pneumonia was the most frequently isolated agent. No significant differences were found between groups for the average days of fever prior to the diagnosis or total days of fever, days of hospital stay, pleural fluid pH (6.8 and 7.0 respectively) and glucose (21 and 31 mg/dl respectively). No differences were either observed for pleural fluid risk factors (pH < 7 and glucose <20mgdl), the presence of extensive pleural effusions, pleural loculations or bands on pleural ultrasonography and positive Gram stain or cultures in the pleural fluid. Surgical patients required oxygen for more days than medical patients (7.7 and 5.1 days; p=0.037). Conclusions: This study failed to find predictive clinical, radiological or pleural fluid parameters, for the requirement of surgical treatment of empyema (Rev Med Chile 2001; 129: 1289-96).

Correlación genotipo-fenotipo de un grupo de pacientes con fibrosis quística

Background: Cystic fibrosis (CF) is the most common lethal autosomic disease in Caucasians, with a global incidence of 1:3000 newborns. More than 900 mutations have been described, involving the Cystic Fibrosis Transmembrane Regulator (CFTR). The ∆F508 mutation is present in 60% of alleles studied worldwide. Aim: To report 25 patients with cystic fibrosis in whom a genetic study was done. Material and methods: Twenty five patients (14 men, aged between 18 months and 25 years) with a diagnosis of cystic fibrosis based on clinical features plus two abnormal sweat tests are reported. The genetic study considered the 20 most common mutations in cystic fibrosis and was done in genomic DNA of peripheral lymphocytes, by polymerase chain reaction. Results: A mutation was found in 75% of analyzed alleles. DF508 was present in 50% of cases (DF508/DF508 in 8 and DF508/other in 11). When DF508 was present, pancreatic insufficiency was always a feature and nutritional status was worse. Respiratory involvement was variable, both for homozygous and heterozygous cases. Other severe mutations such as W1282X and G542X were related to clinical manifestations similar to those found in DF508 mutation. Diagnosis was made before six months of age in 12 patients. The clinical presentation was meconium ileus and there was a family history of the disease in most cases. The majority of cases of early diagnosis presented severe mutations, but milder respiratory symptoms and lesser nutritional compromise at the time of assessment. Conclusions: Most patients studied had a severe cystic fibrosis mutation, which was associated with more severe respiratory, pancreatic and nutritional involvement. The early diagnosis of the disease, which would allow to improve the prognosis and the quality of life, must be emphasized (Rev Med Chile 2002; 130: 475-81)

Experiencia en 10 años de aplicación de fibrobroncoscopia en pacientes pediátricos

: Records ofprocedures done between January 1993 and September 2002 at the Pediatric Service of the Catho-lic University Hospital, were retrospectively reviewed. We evaluated the clinical indications for theprocedures in relation to patient’s age and the correlation between indications and FB findings.

Experiencia clínica en el manejo domiciliario de niños traqueostomizados

Background: Home care of tracheostomized children is considered a safe and low-cost alternative. Aim: To report the experience with tracheostomized children at the Pediatric Respiratory Unit of the Catholic University Hospital. Patients and methods: The records of 16 children (9 male) with tracheostomy (TQ) in home care between 1992 and 1998 were reviewed. Results: The average age at the moment of TQ was 9 months (range 1-30 months) and the postoperative hospital management period was 5 months (range 1-11 months). The average age at discharge was 13 months (range 3 to 30 months). Surgical indication were upper airway obstruction (congenital or acquired subglotic stenosis in three, upper airway malformations in one, vocal cord palsy in one and tracheobronchomalacia in one) and chronic assisted ventilation (severe tracheobronchomalacia in four, pulmonary hypoplasia in two, myopathy in one, central nervous injury in one and bronchopulmonary displasia in one). Overall rate complications were 2 per 100 tracheostomy months during home care and 8 per 100 tracheostomy months during hospital care. No tracheostomy-related deaths were observed. A parenteral education program to teach about tracheostomy management and cardiopulmonary resuscitation was carried out. Conclusions: Tracheostomized children can be safely managed at home (Rev Med Chile 2000; 128: 1221-26)

Experiencia clínica de la utilidad del lavado broncoalveolar en pediatría

Introduccion: Se ha descrito que el lavado broncoalveolar (LBA) tiene utilidad en la determinacion etiologica de pacientes con neumonias de evolucion inhabitual y en pacientes inmunodeprimidos. La informacion publicada es en su mayoria extranjera, existiendo escasa informacion en Chile. Objetivo: Revisar retrospectivamente la experiencia clinica de LBA realizados en el Servicio de Pediatria del Hospital Clinico de la Universidad Catolica entre abril 1993 y julio 2001. Pacientes y Metodo: Se utilizo un fibrobroncoscopio Olympus de 3,6 mm de diametro externo, con una videocamara Sony DXC-C1 utilizando para el LBA 4 a 6 alicuotas de 1 cc/kg (volumen maximo: 15 ml) de suero fisiologico al 0,9% c/u, tomando muestras de secrecion bronquial, las que fueron enviadas para estudio viral, bacteriologico, tuberculosis, hongos y Pneumocystis carinii. Resultados: Se realizaron un total de 97 LBA, analizandose el resultado de 82 LBA de 74 pacientes. Hubo 30 LBA en inmunosuprimidos, cuyos diagnosticos fueron: neumonia 15, neumonia intersticial 9, neumonia con atelectasia 3, distres respiratorio agudo 3. De estos 30 LBA, hubo un total de 14 resultados positivos (46,6%), 10 para germen patogeno (33,3%); CMV 5, reaccion de polimerasa en cadena (PCR) (+) Pneumocystis carinii 2, CMV + Pneumocystis carinii 2. De los 52 LBA en inmunocompetentes los diagnosticos fueron de neumonia con o sin atelectasia 32, sospecha de hemosiderosis 7, tuberculosis 4, bronquiectasias 3 y 6 miscelaneos. Hubo un total de 21 de 44 cultivos positivos (47,7%), aislandose Haemophilus Influenzae en 7, Pseudomona Aeruginosa 4, CMV 3 y Staphylococcus Aureus 2. El LBA cambio la conducta en 29 pacientes (35,3%) y esta incluyo: cambio de terapia antibiotica en 14 pacientes, inicio de ganciclovir en 7. Conclusiones: El LBA es una herramienta de gran ayuda en el paciente que presenta una neumonia inhabitual, en especial en inmunodeprimidos, ya que al determinar un diagnostico etiologico preciso nos permite una eleccion adecuada de tratamiento

Análisis acústico de las sibilancias en lactantes con obstrucción bronquial aguda: Estudio de seguimiento

Background: There is some information about wheeze characteristics in infants, however it is not clear whether the different wheeze patterns relates to prognosis and evolution during the first two years of life. Objectives: To characterize wheezing and spectral pattern of lung sounds in infants with acute bronchiolitis (AB) and in infants with recurrent wheeze (RW) as well as to compare these parameters with the clinical evolution 2 years after admission. Methods: Seventy six AB infants (48 boys), aged 5.5±0.7 months (mean ± SD), 62 RSV (+) and 32 RW infants (20 boys), aged 11.4±2 months were studied during the first week of admission at the hospital. Patients were studied during spontaneous sleep, breathing with a face mask connected to a pneumotachograph at flows of 0.1±0.02L/s. Sounds were registered at baseline and 20 minutes after salbutamol using 2 contact sensors placed at both lower lobes levels. Signals were low-pass filtered, amplified and a Fourier analysis was applied to sounds within a target flow range. Spectral analysis was done between 100 and 1000 HZ. Results: In 40/76 (53%) AB vs 30/34 (88%) RW sinusoidal wheezing (p <0.01; chi2) were observed and a positive bronchodilator response was obtained in 37/76 (49%) AB vs 32/34 (94%) RW (p <0.01; c2). Patients with sinusoidal wheezing (s-w) had more wheezing episodes in follow-up, 26/40 vs 8/36 in complex wheezing (c-w), (p <0.01: c2) and 30/34 in RW (p <0.01; c2). IgE values at 18 months were higher in s-w compared to c-w (63±7 vs 24±5 Iu/mL (p <0.01) and 96±11 Iu/mL in RW (p <0.01). Conclusions: a) Wheezing characteristics in acute bronchiolitis vs recurrent wheezing are different; b) Bronchodilator response relates to wheeze characteristics and c) Higher IgE and more recurrent wheezing episodes are seen in acute bronchiolitis with sinusoidal wheezing. These findings suggest that lung sounds analysis is useful in assessing wheezy patients and have a value to identify infants on risk of developing asthma (Rev Med Chile 2002; 130: 760-7)

Estridor en el paciente pediátrico: Estudio descriptivo

Introduccion: El estridor es un ruido respiratorio musical, que se presenta predominantemente durante la inspiracion y que resulta del paso de un flujo turbulento por una zona de obstruccion parcial de la via aerea. En reportes previos, la laringomalacia es su principal causa (65 a 75%) y se ha encontrado asociacion de dos o mas anomalias de la via aerea en un promedio del 15% de los casos. En la literatura nacional existen escasas publicaciones en relacion al tema. Objetivo: Revisar nuestra experiencia de 10 anos en el estudio de pacientes con estridor. Pacientes y metodos: Entre marzo 1993 y julio 2003 se realizaron 806 fibrobroncoscopias flexibles (FBC) con un fibrobroncoscopio Olympus BF3C20 y BF3C30. La indicacion del estudio por estridor se presento en 133 pacientes (16,5%). Todos recibieron sedacion, oxigeno por canula nasal y monitorizacion continua cardio-respiratoria. Resultados: La edad promedio fue 10,6 meses (rango entre 5 dias y 71 meses), 74 casos eran de sexo masculino (55,6%). El estridor fue congenito en 104 casos (78,2%) y las principales anomalias de la via aerea fueron laringomalacia en 95 pacientes (71,4%), estenosis subglotica en 13 casos (9,8%) y traqueomalacia en 10 pacientes (7,5%). De los 95 casos de laringomalacia, 19 (20%) presentaron asociacion con otra lesion de la via aerea en forma concomitante, dentro de las que se incluyen bronquio traqueal, traqueomalacia y paralisis de cuerdas vocales entre otras. Nuestros hallazgos son comparables con los descritos previamente en la literatura internacional. Conclusion: El estudio de un paciente con estridor debe incluir la evaluacion de la via aerea superior e inferior