[Pediatric tracheostomy: Ten year experience in an Intensive Care Unit]. / Traqueostomía en niños: Experiencia de 10 años en una Unidad de Cuidados Intensivos Pediátricos.

INTRODUCTION: Pediatric tracheostomy indications have changed over the last 30 years, from acute and transient pro cedures secondary to airway obstruction to programmed tracheostomies indicated due to the need for chronic use of mechanical ventilation (MV). OBJECTIVE: To describe indications and morbidity associated with pediatric tracheostomies during a ten-year period. PATIENTS AND METHODS: Descrip tive study. Clinical records review of discharged patients (< 15 years old) tracheostomized during their hospital stay between 2005 and 2015. Demographic and clinical variables were evaluated before and after tracheostomy, stay in intensive care unit, age at the time of the tracheostomy, indication of tracheostomy, early complications (< 7 days), late complications (> 7 days), and mortality. RESULTS: 59 children with tracheostomy were analyzed, 36 (59%) tracheostomies were performed in children under 6 months, and 39 (60%) in males. 23 (39%) had a confirmed or under study genopathy and 25 (42%) had congenital heart disease. The main indications for tracheostomy were 58% secondary to airway disease and 42% due to chronic use of MV. Within the airway disease group, subglottic steno sis, vocal cord paralysis, and tracheobronchomalacia were the principal reasons for indication, and in the group of chronic use of MV, the main causes were bronchopulmonary dysplasia and chronic lung disease. We did not find tracheostomy-related mortality. 89% of the patients were discharged with tracheostomy and 59% with chronic use of MV. The probability of being discharged with a tracheos tomy was higher in younger patients while the chronic use of MV at discharge was higher in patients with a greater number of extubation failures before tracheostomy. CONCLUSION: Tracheostomy is a safe procedure in children, where the predominant causes of indication are airway disease and the need for chronic use of MV. Most children with tracheostomies are discharged with tracheostomy and chronic use of MV. Younger children, those with difficult weaning, confirmed or suspected ge nopathy, or special health needs are at greater risk of needing tracheostomy and chronic use of MV.

[Prevalence of sudden death syndrome among children]. / Síndrome de muerte súbita del lactante: prevalencia y cambios en los últimos años en Chile.

BACKGROUND: The sudden infant's death syndrome (SD) is the leading cause of death in children under one year. Despite advances in its study, the pathogenesis has not been yet fully elucidated. AIM: To assess the prevalence of SD in Chilean infants and its changes in recent years. MATERIAL AND METHODS: Review of birth and death databases of the Ministry of Health from 1997 to 2009. All cases diagnosed as SD, according to the lnternational Classification of Diseases, 10th edition, were selected. A demographic analysis was performed and mortality rates for each year were calculated. RESULTS: We identified 1442 cases of SD (847 males, 517 deaths at home). The median age of death was 2 months (0 to 11.0 months). Ninety six percent of deaths occurred in children aged <6 months. Mortality rate for SD was 0.45/1000 live births. There was a 23% reduction between 1997 and 2009. When analyzing geographic distribution, more cases were found in the Southern latitudes of the country. CONCLUSIONS: The overall rate of SD in Chile is higher than in European countries and in North America. The observed decrease in cases over the years is still far from optimal.

Síndrome de muerte súbita del lactante: prevalencia y cambios en los últimos años en Chile / Prevalence of sudden death syndrome among children

Background: The sudden infant's death syndrome (SD) is the leading cause of death in children under one year. Despite advances in its study, the pathogenesis has not been yet fully elucidated. Aim: To assess the prevalence of SD in Chilean infants and its changes in recent years. Material and Methods: Review of birth and death databases of the Ministry of Health from 1997 to 2009. All cases diagnosed as SD, according to the lnternational Classification of Diseases, 10th edition, were selected. A demographic analysis was performed and mortality rates for each year were calculated. Results: We identified 1442 cases of SD (847 males, 517 deaths at home). The median age of death was 2 months (0 to 11.0 months). Ninety six percent of deaths occurred in children aged <6 months. Mortality rate for SD was 0.45/1000 live births. There was a 23% reduction between 1997 and 2009. When analyzing geographic distribution, more cases were found in the Southern latitudes of the country. Conclusions: The overall rate of SD in Chile is higher than in European countries and in North America. The observed decrease in cases over the years is still far from optimal.

Vía aérea difícil / Difficult airway

Difficult airway is a life-threatening situation which compromises the permeability of the upper airway and thus adequate ventilation and oxygenation. Multiple factors, acute and chronic such as: infectious, neoplastic and trauma have been associated with critical airway. Morbidity and mortality related to a difficult airway management remains as a significant problem in children, so is essential for the pediatric health team to be trained to recognize and anticipate situations that in clinical practice might determine a critical airway. The aim of this review is to provide concepts and guidance to assess patients with potentially difficult airway.

Una vía aérea difícil condiciona una situación con riesgo vital, ya que pone en peligro la permeabilidad de la vía aérea superior y con esto la capacidad de mantener una adecuada ventilación y oxigenación. Múltiples factores, tanto agudos como crónicos, entre ellos factores anatómicos propios del niño/a, complicaciones infecciosas, neoplásicas y/o traumáticas se han asociado con una vía aérea crítica. La morbilidad y mortalidad asociada al manejo inadecuado de esta condición continua siendo un problema significativo en la edad pediátrica; siendo fundamental que el equipo de salud se encuentre entrenado en reconocer y anticipar situaciones que en la práctica clínica podrían asociarse con una vía aérea difícil o crítica. El objetivo de la presente revisión es otorgar conceptos y una orientación en el enfrentamiento de los pacientes con una vía aérea potencialmente difícil.

[Presence of mutations associated with ganciclovir resistance in cytomegalovirus UL97 gene]. / Búsqueda de mutaciones en el gen UL97 asociadas a resistencia a ganciclovir en citomegalovirus obtenidos desde muestras biológicas de pacientes chilenos.

BACKGROUND: Long term use of ganciclovir (GCV) is associated with acquired resistance to it. Ninety percent of the responsible mutations occur in cytomegalovirus (CMV) UL 97 gene. AIM: To search for these mutations, comparing nucleotide sequences of CMV-positive samples from post transplant and immunocompromised patients receiving GCV, with sequences of CMV isolates obtained from subjects not exposed to the drug. PATIENTS AND METHODS: Codons 440 to 465 of gene UL 97, including the most common mutations causing resistance to GCV, were amplified in 33 plasma samples from patients exposed to GCV and in 15 urine samples of newborns. Both populations and their nucleotide sequences were compared with the prototype strain CMV AD169. RESULTS: Samples of exposed patients had multiple mutations but only one had a mutation associated with clinical resistance (M460I). Eight subjects had the D605E mutation, whose role in resistance is controversial. The remaining 150 mutations were silent mutations. CONCLUSIONS: A low frequency of mutations associated with CMV resistance to GCV was found in these exposed and unexposed samples. These mutations may reflect coexistence of multiple genetic variants of CMV. The absence of clinical expression of resistance, even with these mutations, can be explained by the use of GCV for a shorter lapse than that associated with the appearance of resistance.

Búsqueda de mutaciones en el gen UL 97 asociadas a resistencia a ganciclovir en citomegalovirus obtenidos desde muestras biológicas de pacientes chilenos / Presence of mutations associated with ganciclovir resistance in cytomegalovirus UL 97 gene

Background: Long term use of ganciclovir (GCV) is associated with acquired resistance to it. Ninety percent of the responsible mutations occur in cytomegalovirus (CMV) UL 97 gene. Aim: To search for these mutations, comparing nucleotide sequences of CMV-positive samples from post transplant and immunocompromised patients receiving GCV, with sequences of CMV isolates obtained from subjects not exposed to the drug. Patients and Methods: Codons 440 to 465 of gene UL 97, in-cluding the most common mutations causing resistance to GCV, were amplifed in 33 plasma samples from patients exposed to GCV and in 15 urine samples of newborns. Both populations and their nucleotide sequences were compared with the prototype strain CMV AD169. Results: Samples of exposed patients had multiple mutations but only one had a mutation associated with clinical resistance (M460I). Eight subjects had the D605E mutation, whose role in resistance is controversial. The remaining 150 mutations were silent mutations. Conclusions: A low frequency of mutations associated with CMV resistance to GCV was found in these exposed and unexposed samples. These mutations may refect coexistence of multiple genetic variants of CMV. The absence of clinical expression of resistance, even with these mutations, can be explained by the use of GCV for a shorter lapse than that associated with the appearance of resistance.

[Ambulatory management of community acquired pneumonia in the elderly]. / Manejo de la neumonía comunitaria del adulto mayor en el ámbito ambulatorio.

Community Acquired Pneumonia (CAP) is the first cause of death by respiratory disease in Chile and the first specific cause of death in people over 80 years of age. The geriatric population has a greater risk of suffering pneumonia, its complications and consequently dying. This is not only related to chronological age but also to certain factors related to ageing such as the presence of comorbidity, malnutrition, and cognitive impairment. An atypical presentation that delays the diagnosis and treatment also increases the risk of complications. CAP in the elderly is caused by the same pathogens that cause it in younger patients. S pneumoniae is the main pathogen followed by viral infections particularly in winter. An important strategy to reduce CAP related health costs, is the identification of patients who are at low risk of complications and who therefore could be managed at home. Optimum management of CAP in the elderly includes early diagnosis and the definition of clinical severity, early antibiotic treatment at the right dose and for an adequate length of time and a correct decision whether the patient should be managed in hospital or at home.