High-gradient magnetophoretic bead trapping for enhanced electrochemical sensing and particle manipulation.

Magnetic particles are routinely used in many biochemical techniques. As such, the manipulation of these particles is of paramount importance for proper detection and assay preparation. This paper describes a magnetic manipulation and detection paradigm that allows sensing and handling highly sensitive magnetic bead-based assays. The simple manufacturing process presented in this manuscript employs a CNC machining technique and an iron microparticle-doped PDMS (Fe-PDMS) compound to create magnetic microstructures that enhance magnetic forces for magnetic bead confinement. Said confinement, generates increases in local concentrations at the detection site. Higher local concentrations increase the magnitude of the detection signal, leading to higher assay sensitivity and lower limit of detection (LOD). Furthermore, we demonstrate this characteristic signal enhancement in both fluorescence and electrochemical detection techniques. We expect this new technique to allow users to design fully integrated magnetic bead-based microfluidic devices with the goal of preventing sample losses and enhancing signal magnitudes in biological experiments and assays.

Characterization of muscle mass, strength and mobility of critically ill patients with SARS-CoV-2 pneumonia: Distribution by sex, age, days on mechanical ventilation, and muscle weakness.

Objective: Quantify and categorize by sex, age, and time spent on mechanical ventilation (MV), the decline in skeletal muscle mass, strength and mobility in critically ill patients infected with SARS-CoV-2 and requiring mechanical ventilation while at intensive care unit (ICU). Design: Prospective observational study including participants recruited between June 2020 and February 2021 at Hospital Clínico Herminda Martin (HCHM), Chillán, Chile. The thickness of the quadriceps muscle was evaluated by ultrasonography (US) at intensive care unit admission and awakening. Muscle strength and mobility were assessed, respectively, through the Medical Research Council Sum Score (MRC-SS) and the Functional Status Score for the Intensive Care Unit Scale (FSS-ICU) both at awakening and at ICU discharge. Results were categorized by sex (female or male), age (<60 years old or ≥60 years old) and time spent on MV (≤10 days or >10 days). Setting: Intensive care unit in a public hospital. Participants: 132 participants aged 18 years old or above (women n = 49, 60 ± 13 years; men n = 85, 59 ± 12 years) admitted to intensive care unit with a confirmed diagnosis of severe SARS-CoV-2 and requiring MV for more than 48 h were included in the study. Patients with previous physical and or cognitive disorders were excluded. Interventions: Not applicable. Results: Muscle thickness have significantly decreased during intensive care unit stay, vastus intermedius (-11%; p = 0.025), rectus femoris (-20%; p < 0.001) and total quadriceps (-16%; p < 0.001). Muscle strength and mobility were improved at intensive care unit discharge when compared with measurements at awakening in intensive care unit (time effect, p < 0.001). Patients ≥60 years old or on MV for >10 days presented greater muscle loss, alongside with lower muscle strength and mobility. Conclusion: Critically ill patients infected with SARS-CoV-2 and requiring MV presented decreased muscle mass, strength, and mobility during their intensive care unit stay. Factors associated with muscle mass, such as age >60 years and >10 days of MV, exacerbated the critical condition and impaired recovery.

Continuous prolonged prone positioning in COVID-19-related ARDS: a multicenter cohort study from Chile.

BACKGROUND: Prone positioning is currently applied in time-limited daily sessions up to 24 h which determines that most patients require several sessions. Although longer prone sessions have been reported, there is scarce evidence about the feasibility and safety of such approach. We analyzed feasibility and safety of a continuous prolonged prone positioning strategy implemented nationwide, in a large cohort of COVID-19 patients in Chile. METHODS: Retrospective cohort study of mechanically ventilated COVID-19 patients with moderate-to-severe acute respiratory distress syndrome (ARDS), conducted in 15 Intensive Care Units, which adhered to a national protocol of continuous prone sessions ≥ 48 h and until PaO2:FiO2 increased above 200 mm Hg. The number and extension of prone sessions were registered, along with relevant physiologic data and adverse events related to prone positioning. The cohort was stratified according to the first prone session duration: Group A, 2-3 days; Group B, 4-5 days; and Group C, > 5 days. Multivariable regression analyses were performed to assess whether the duration of prone sessions could impact safety. RESULTS: We included 417 patients who required a first prone session of 4 (3-5) days, of whom 318 (76.3%) received only one session. During the first prone session the main adverse event was grade 1-2 pressure sores in 97 (23.9%) patients; severe adverse events were infrequent with 17 non-scheduled extubations (4.2%). 90-day mortality was 36.2%. Ninety-eight patients (24%) were classified as group C; they exhibited a more severe ARDS at baseline, as reflected by lower PaO2:FiO2 ratio and higher ventilatory ratio, and had a higher rate of pressure sores (44%) and higher 90-day mortality (48%). However, after adjustment for severity and several relevant confounders, prone session duration was not associated with mortality or pressure sores. CONCLUSIONS: Nationwide implementation of a continuous prolonged prone positioning strategy for COVID-19 ARDS patients was feasible. Minor pressure sores were frequent but within the ranges previously described, while severe adverse events were infrequent. The duration of prone session did not have an adverse effect on safety.

Fisiología respiratoria hipoxemia / Hypoxemia

La hipoxemia ocurre producto de una inadecuada captación de oxígeno a nivel pulmonar y se manifiesta como presión arterial de oxígeno menor a 60 mmHg o saturación arterial de oxígeno menor de 90%. Los mecanismos fisiopatológicos por los cuales se puede producir hipoxemia son hipoventilación, alteración del equilibrio ventilación perfusión, shunt cardiaco, alteración de la difusión y disminución de la presión inspirada de oxígeno. La comprensión de estos mecanismos es fundamental para entender su presentación clínica en distintas enfermedades.

Hypoxemia is the name given to inadequate uptake in the lung and is defined as an arterial oxygen pressure less than 60 mmHg or arterial oxygen saturation less than 90%. The pathophysiological mechanisms that can produce hypoxemia are: hypoventilation, ventilation perfusion mismatch, cardiac shunt, diffusion impairment and decreased inspired oxygen pressure. Full comprehension of these mechanism facilitates the understanding of hypoxemia among different diseases.

A Single-Layer PDMS Chamber for On-Chip Bacteria Culture.

On-chip cell culture devices have been actively developed for both mammalian cells and bacteria. Most designs are based on PDMS multi-layer microfluidic valves, which require complicated fabrication and operation. In this work, single-layer PDMS microfluidic valves are introduced in the design of an on-chip culture chamber for E. coli bacteria. To enable the constant flow of culturing medium, we have developed a (semi-)always-closed single-layer microfluidic valve. As a result, the growth chamber can culture bacteria over long duration. The device is applied for the whole-cell detection of heavy metal ions with genetically modified E. coli. The platform is tested with culturing period of 3 h. It is found to achieve a limit-of-detection (LoD) of 44.8 ppb for Cadmium ions.

Concordance in Discriminating Recordings of Different Lung Sounds Between Physiotherapists.

BACKGROUND: Auscultation is a fundamental part of the physical examination, but its utility has been questioned due to the low inter-rater concordance. We therefore sought to evaluate the concordance of the discrimination of lung sound recordings between experienced physiotherapists. METHODS: Lung sound recordings were selected and validated by an expert panel when Fleiss κ concordance was > 0.75. Eleven recordings were played for subject recognition using a portable computer in their workplace. Results were analyzed using Fleiss κ when looking for concordance between physiotherapists. Univariate regression was performed to determine if there was an association with clinical training, years of experience, academic accomplishment, or university affiliation. RESULTS: Sixty-nine physiotherapists with a median of 4 years of working experience (interquartile range 2-6 y) completed the study. There was moderate concordance (κ = 0.562; 95% CI 0.462-0.605) for overall lung sound recording discrimination. For continuous and noncontinuous lung sound recordings, discrimination concordance was substantial (κ = 0.63 and κ = 0.76, respectively). A bivariate analysis revealed that years of experience presented an inverse association with stridor recognition. CONCLUSIONS: Concordance between physiotherapists in discriminating recorded lung sounds was moderate. The ability to recognize stridor was inversely associated with years of work experience.

Perfil clínico y epidemiológico de los casos de tuberculosis atendidos en una red de salud universitaria en Santiago de Chile entre los años 2000-2010 / Clinical and epidemiological profile of tuberculosis in a university hospital in Santiago, Chile

Background:The incidence and epidemiological profile of tuberculosis (TB) has changed significantly in the recent years in Chile. Aim: To evaluate the clinical and epidemiological characteristics of TB cases diagnosed in the last decade at a university hospital in Santiago. Material and Methods: The Mycobacterium tuberculosis culture registry of the microbiology laboratory was reviewed. Medical records of patients with a positive culture registered between 2000 and 2010 were retrieved and analyzed. Results: Two hundred forty positive Mycobacterium tuberculosis cultures were identified and the medical records of 158 of these patients were accessed for analysis. The median age was 53 years (range: 3 to 89), 55.1% were female and nearly 42% had extra-pulmonary TB. Among known risk factors, 32.9% of patients were older than 65 years, 4.4% were health care workers and 3.9% immigrants. Twenty eight percent (41/145) had some type of immunosuppression at diagnosis: 11.7% HIV infection and 16.6% were using immunosuppressive drugs. In this group, a previous tuberculin skin test was done in only 5 cases (12.2%). Adverse events related to TB treatment were reported in 21.3% of cases (17/80). No cases of fulminant hepatitis or death from this cause were identified. Four of 92 patients that had a complete follow up during treatment, died. Two of these patients were receiving steroids. Conclusions:Almost one third of TB cases occurred among immunosuppressed patients and 42% were extra-pulmonary forms. The prevention of TB reactivation in this group should be strengthened.

[Clinical and epidemiological profile of tuberculosis in a university hospital in Santiago, Chile]. / Perfil clínico y epidemiológico de los casos de tuberculosis atendidos en una red de salud universitaria en Santiago de Chile entre los años 2000-2010.

BACKGROUND: The incidence and epidemiological profile of tuberculosis (TB) has changed significantly in the recent years in Chile. AIM: To evaluate the clinical and epidemiological characteristics of TB cases diagnosed in the last decade at a university hospital in Santiago. MATERIAL AND METHODS: The Mycobacterium tuberculosis culture registry of the microbiology laboratory was reviewed. Medical records of patients with a positive culture registered between 2000 and 2010 were retrieved and analyzed. RESULTS: Two hundred forty positive Mycobacterium tuberculosis cultures were identified and the medical records of 158 of these patients were accessed for analysis. The median age was 53 years (range: 3 to 89), 55.1% were female and nearly 42% had extra-pulmonary TB. Among known risk factors, 32.9% of patients were older than 65 years, 4.4% were health care workers and 3.9% immigrants. Twenty eight percent (41/145) had some type of immunosuppression at diagnosis: 11.7% HIV infection and 16.6% were using immunosuppressive drugs. In this group, a previous tuberculin skin test was done in only 5 cases (12.2%). Adverse events related to TB treatment were reported in 21.3% of cases (17/80). No cases of fulminant hepatitis or death from this cause were identified. Four of 92 patients that had a complete follow up during treatment, died. Two of these patients were receiving steroids. CONCLUSIONS: Almost one third of TB cases occurred among immunosuppressed patients and 42% were extra-pulmonary forms. The prevention of TB reactivation in this group should be strengthened.

Experiencia clínica de la utilidad del lavado broncoalveolar en pediatría / Bronchoalveolar lavage in children

Introducción: Se ha descrito que el lavado broncoalveolar (LBA) tiene utilidad en la determinación etiológica de pacientes con neumonías de evolución inhabitual y en pacientes inmunodeprimidos. La información publicada es en su mayoría extranjera, existiendo escasa información en Chile. Objetivo: revisar restrospectivamente la experiencia clínica de LBA realizados en el servicio de pediatría del Hospital Clínico de la Universidad Católica entre abril 1993 y julio 2001. pacientes y métodos: Se utilizó un fibrobroncoscopio olympus de 3,6 mm de diámetro externo, con una vieocámara sony DXC-C1 utilizando para el LBA 4 a 6 alícuotas de 1 cc/kg (volumen máximo: 15 ml) de suero fisiológico al 0,9 por ciento c/u, tomando muestras de secreción bronquial, las que fueron enviadas para estudio viral, bacteriológico, tuberculosis, hongos y pneumocystis carinii. Resultados: se realizaron un total de 97 LBA, analizándose el resultado de 82 LBA de 74 pacientes. hubo 60 LBA en inmunosuprimidos, cuyos diagnósticos fueron: neumonía 15, neumonía intersticial 9, neumonía con atelectasia 3, distrés respiratorio agudo 3. de estos 30 LBA, hubo un total de 14 resultados positivos (46,6 por ciento), 10 para germen patógeno (33,3 por ciento); CMV 5, reacción de polimerasa en cadena (PCR) (+) pneumocystis carinii 2, CMV + pneumocystis carinii2. De los 52 LBA en inmunocompetentes los diagnïsticos fueron de neumonía con o sin atelectasia 32, sospecha de hemosiderosis 7, tuberculosis 4, bronquiectasias 3 y 6 misceláneos. Hubo un total de 21 de 44 cultivos positivos (47,7 por ciento), aislándose haemophilus influenzae en 7, pseudomona aeruginosa 4, CMV 3 y staphylococcus aureus 2. El LBA cambió la conducta en 29 pacientes (35,3 por ciento) y ésta incluyó: cambio de terapia antibiótica en 14 pacientes, inicio de ganciclovir en 7. Conclusiones: el LBA es una herramienta de gran ayuda en el paciente que presenta una neumonía inhabitual, en especial en inmunodeprimidos, ya que al determinar un diagnóstico preciso nos permite una elección adecuada de tratamiento

Traqueobroncomalacia en pacientes pediátricos: experiencia clínica / Tracheobronchomalacia in pediatric patients: clinical experience

Background: Tracheobronchomalacia is characterized by a deficiency in the cartilaginous support of the trachea and bronchi and hypotony in the myoelastic elements, that lead to different levels of airway obstruction. Aim: To report our experience in the treatment of traqueobronchomalacia. Material and methods: Retrospective review of 24 patients with tracheomalacia of different levels (3 tracheobronchomalacia, 3 laryngotracheomalacia) and 8 patients with bronchomalacia. Results: The age at diagnosis ranged from 9 days to 9 years. Clinical presentation was recurrent wheezing in 19 patients, stridor in 6 and atelectasis in 4. The associated factors were neurological impairment in 8, congenital heart disease in 10 and prolonged mechanical ventilation in 4. The diagnosis was done by flexible bronchoscopy in all patients, using sedation and allowing spontaneous breathing. At the moment of diagnosis, treatment consisted in oxygen supply in 14 patients, physiotherapy in 21, õ2 adrenergic agonists in 27, racemic epinephrine in 8, mechanical ventilation in 12, ipratropium bromide in 5 and inhaled steroids in 13. After diagnosis, 24 patients received bronchodilator therapy with ipratropium bromide, 15 received racemic epinephrine and 22 received inhaled steroids. In 21, õ2 adrenergic agonists were discontinued. Thirteen patients required ventilation support and home oxygen. Twenty two patients showed a satisfactory clinical evolution and 6 patients died. Conclusions: The clinical presentation of tracheobronchomalacia is varied and diagnosis is done by flexible bronchoscopy. Treatment will depend on the severity of the disease, but õ2 adrenergic agonists should be excluded

Análisis acústico de las sibilancias en lactantes con obstrucción bronquial aguda: estudio de seguimiento / Acoustic analysis in wheezy infants: a follow up study

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 5.5ñ0.7 months (mean ñ SD), 62 RSV (+) and 32 RW infants (20 boys), aged 11.4ñ2 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 0.1ñ0.02L/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 percent) AB vs 30/34 (88 percent) RW sinusoidal wheezing (p <0.01; chi2) were observed and a positive bronchodilator response was obtained in 37/76 (49 percent) AB vs 32/34 (94 percent) RW (p <0.01; _2). 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: _2) and 30/34 in RW (p <0.01; _2). IgE values at 18 months were higher in s-w compared to c-w (63ñ7 vs 24ñ5 Iu/mL (p <0.01) and 96ñ11 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

Tienda invertida de administración de oxígeno para uso domiciliario: descripción de un caso clínico / The use of inverted tent in home oxygen therapy: a clinical case

Los avances en medicina pediátrica han permitido el desarrollo de la oxigenoterapia en domicilio para pacientes con Insuficiencia Respiratoria Crónica. Existen diversos equipos para la administración de oxígeno en domicilio que se ocupan de acuerdo a las características clínicas de cada paciente. Presentamos el caso clínico de un niño de tres años con síndrome de Down, displasia broncopulmonar y apnea obstructiva del sueño que se presentó con hipoxemia nocturna severa debido a la mala tolerancia a la cánula nasal y otros equipos. Este paciente fue sometido a oxigenoterapia nocturna a través de una tienda invertida alimentada con un concentrador y un sistema venturi, observándose una mejoría en la saturación promedio de oxígeno de 87 ñ 3 a 95 ñ 3 por ciento. La tienda fue construida de material sintético, económico y disponible. Sugerimos que la tienda invertida de oxígeno puede ser una alternativa en pacientes con malformaciones cráneo-faciales y/o intolerancia a equipos convencionales de administración de oxígeno

Apoyo ventilatorio domiciliario en niños con insuficiencia respiratoria crónica: experiencia clínica / Home ventilation in children with chronic respiratory failure: a clinical trial

Introducción: En los últimos años se han desarrollado sistemas de apoyo ventilatorio en domicilio (SAVED), que han logrado tratar pacientes con insuficiencia respiratoria crónica en su hogar. Objetivo: revisar nuestra experiencia en los pacientes con SAVED. Pacientes y Método: se revisaron las fichas de los 15 pacientes ( 9 mujeres) con SAVED dados de alta del Servicio de Pediatría del Hospital Clínico de la Pontificia Universidad Católica de Chile, entre enero de 1993 y diciembre 2000. Se describen las características del grupo y su seguimiento. Resultados: sus edades al alta fluctuaron entre 5 meses y 15 años; 6 tenían enfermedad neuromuscular, 4 daño pulmonar crónico, 1 deformidad torácica y 4 traqueobroncomalacia grave. Doce requirieron traqueostomía, de estos, 4 utilizaron ventilación mecánica (PLV-102, LifeCare) y 8 CPAP con generador de flujo (Downs) y válvula de PEEP, y 3 ventilación nasal a través de BIPAP. El alta fue entre 2 y 4 meses desde el ingreso y la implementación del SAVED entre 1 y 4 meses, de acuerdo a la realidad familiar y previsional. El período de seguimiento fue de 3 meses a 8 años. La tasa de reingreso fue 2,5 y 0,4 ingresos/paciente/año por morbilidad y por falla de sistema respectivamente, el tiempo promedio de estadía en el hospital fue de 16,5 ñ 9 días/año. Se logró la retirada del SAVED en 5 pacientes y 1 niño falleció debido a su enfermedad neurológica. En resumen, nuestra experiencia demuestra que los SAVED son una alternativa real en el manejo de pacientes con insuficiencia respiratoria crónica grave. Esta terapia presenta escasas complicaciones, permite enviar al paciente a su casa y disminuye en forma significativa los costos del tratamiento

Monitorización continua nocturna de saturación arterial de oxígeno en pacientes pediátricos con sospechas de hipoxemia / Continuous nocturnal monitoring of arterial oxygen saturation in paediatric patients with suspected hypoxia

La monitorización de la saturación arterial del oxígeno (SaO2) es utilizada en la detección de hipoxemia en pacientes con daño pulmonar crónico; una medición única diurna (MUD) puede subestimar la presencia de hipoxemia durante el sueño y la alimentación. Describimos los resultados de los estudios de SaO2 con medición nocturna (MCN) realizados entre agosto de 1993 y noviembre de 1998, y evaluamos la sensibilidad y especificidad de una MUD y MCN en la detección de hipoxemias. Se realizaron 290 MCN, en 167 pacientes, utilizando un oxímetro de pulso Ohmeda Biox 3700, con almacenamiento automático de 8 horas de señal de SaO2 y frecuencia cardíaca. Las indicaciones del estudio fueron por sospecha de hipoxemia (SH) en 243 estudios (83,8 por ciento) (130 pacientes: 103 con displasia broncopulmonar (DBP), 66 con daño pulmonar crónico (DPC), 24 con cardiopatía congénita) y por sospecha de apnea (SA) durante el sueño en 47 casos (16,2 por ciento). 42,5 por ciento de los exámenes fueron realizados en menores de 6 meses, y se observó una edad significativamente mayor en SA que en SH (mediana 42 vs 7 meses, respectivamente; p < 0.01 Mann Whitney). De los 167 pacientes, 53,3 por ciento eran hombres y siendo la diferencia significativa solo en el grupo SH con DBP (61 por ciento) vs SH con DPC. En 45,5 por ciento de los pacientes se realizó másde un estudio, correspondiendo 93 por ciento de SH. Se encontraban con oxigenoterapia 44,5 por ciento de los pacientes, de estos 42,1 por ciento tenían DBP y 29,7 por ciento DPC. En 28 estudios se comparó una MUD con MCN de 8 horas, 18 SH con DBP y 10 SH con DPC, encontrando una SaO2 por MUD de 92,2 ñ 2,3 por ciento y 94,1 ñ 1,9 por ciento, respectivamente, y por MCN una SaO2 < 90 por ciento en 23,5 por ciento y 27,7 por ciento del tiempo del estudio, respectivamente. La MUD para indicación de oxigenoterapia mostró una sensibilidad de 15,5 por ciento y específicidad de 100 por ciento, al considerar positiva la indicación con > 10 por ciento del tiempo del estudio MCN con SaO2 < 90 por ciento. Concluímos que la medición única diurna de SaO2 subestima los episodios de hipoxemia, por lo que recomendamos la monitorización continua nocturna de la SaO2 para la evaluación de hipoxemia y manejo de oxigenoterapia en pacientes con sospecha de hipoxemia

Experiencia clínica en el manejo domiciliario de niños traqueostomizados / Clinical experience in home care of children with a tracheostomy

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

Oxigenoterapia domiciliaria en niños con insuficiencia respiratoria crónica / Home oxygen therapy in children with chronic respiratory failure

Background: Home oxygen therapy improves survival and quality of the life in adults with chronic obstructive airwais disease. The few studies about home oxigen therapy in children show improvements in weight gain, school performance and decreasesin hospitalization expenses. Aim: To report our experience in home oxygen therapy in children followed for six month to four years. Patients and methods: Fifty five children, less than 15 years old, discharged from a University hospital with the diagnosis of chronic respiratory failure, were followed for up at their homes. Results: Dicharge diagnoses were bronchopulmonary dysplasia in 36 percent of children, postinfectious pulmonary damage in 22 percent, neonatal distress in 13 percent, chronic aspiration in 9 percent, cystic fibrosis in 7 percent and miscellaneous in 13 percent. Forty six completed at least 6 months of follow up, five moved to other hospitals, three required ventilatory support and one died. Oxygen was discontinued in 33 patients, and this occurred before the ninth month of follow up in 88percent of those children. Neonatal distress and bronchopulmonary dysplasia had the best prognoses, and oxygen was discontinued at 4ñ1 and 5.7ñ3 months respectively. Patients with postinfectious pulmonary disease had a higher incidence of bronchoneumoniae, and those with bronchopulmonary dysplasia a higher incidence of acute bronchiolitis, that motivated hospital admissions. Expenses due to home oxygen were lower than hospitalization costs. No adverse effects were detected. Conclusions: Infants and newborns on home oxygen therapy have a good prognosis, specially those with reversible diseases. this type of therapy allows an earlier hospital discharge with considerable cost reductions

Intubación endotraqueal: una técnica cuyo conocimiento debe generalizarse / Endotracheal intubation: a technique whose knowledge have to generalize

El manejo adecuado de la vía aérea es una prioridad en la resucitación cardiopulmonar, independiente de la edad del paciente. La intubación endotraqueal en pediatría constituye un procedimiento de gran importancia por el riesgo vital que conlleva y la destreza requerida para realizarla, sea en situación de emergencia o en forma electiva. Este procedimiento obliga al conocimiento de la vía aérea, de la función de los reflejos protectores de la misma, de los medicamentos necesarios para el control de los reflejos y del cuidado integral del niño

Tabaquismo y otros factores de riesgo cardiovascular en una población laboral de Santiago / Smoking and other cardiovascular risk factors in a working population of Santiago, Chile

Tabaquismo, hipertensión arterial, obesidad y otros factores de riesgo cardiovascular fueron estudiados en una población laboral de 4.827 personas del Area Metropolitana (46,61% de mujeres y 53,39% de hombres). La presencia de tabaquismo observado fue de 44,91% para la población total, fue inversamente proporcional a la edad y el índice ponderal (r = -0,978 y r = -0,995 respectivamente). La prevalencia de tabaquismo mostró predominio en el sexo masculino en todos los subgrupos etarios, pero sifnificancia estadística sólo en la cuarta y quinta década (p < 0,01). La presencia de hipertensión arterial en nuestra población fue de 16,98% para hombres y 14,18% para mujeres), valores que se correlacionaron en forma directa con el índice ponderal (r = 0,993). Los niveles de presión arterial sistólica y diastólica fueron significativamente mayores en la población no fumadora (p < 0,01)