4; 95% CI: 2.5 to 4.6). 29 In the evaluation of 229 patients admitted to the ICU for AVB, age was found to be inversely proportional to the time spent in the ICU and time in ventilatory support; 30 the same was observed in a prospective study of 1,456 patients with AVB, which compared hospitalization in the ICU and in the hospital ward and showed that age younger than 2 months was as a risk factor for ICU admission (26% versus 53%; OR = 4.1; Selisistat order 95% CI: 2.1 to 8.3). 31 In the evaluation of 310 patients younger than 12 months with

AVB, it was concluded that younger age was the main factor associated with the severity of clinical manifestations, 32 which was also observed in the evaluation of 284 patients admitted to the ICU for AVB, where age less than 6 weeks was the main risk factor, accounting for 45% of the patients. 23 The younger the child, the lower the levels of hemoglobin oxygen saturation in www.selleckchem.com/products/Rapamycin.html 206 patients hospitalized for AVB by RSV; it was shown that for each month younger the child was, there was a reduction in 0.41% in oxygen saturation. 28 The relationship of age and presence of hospitalization for respiratory infection could be observed in the evaluation of 347 patients with acute respiratory infection, 234 inpatients and 112 outpatients, where the age of hospitalized patients was younger (8 versus 19 months, p < 0.001). 33 Breastfeeding is protective factor against severe

AVB. A study of 12,474 children with bronchiolitis, of whom 1,588 required hospitalization, demonstrated that breastfeeding not starting in the maternity ward lead to a higher risk factor for hospitalization for AVB.20 A Brazilian study with 175 children hospitalized for AVB demonstrated that duration of exclusive breastfeeding was inversely related to the duration of oxygen use and of hospitalization, indicating that for every month of exclusive breastfeeding there was a decrease of 11 hours in the time of oxygen use.34 Children weaned before one month of life had a 7.7-fold greater risk of being hospitalized for AVB.7 Megestrol Acetate The importance of breastfeeding was further demonstrated in a study with 240 children hospitalized for AVB that concluded that breastfeeding an infant for less

than four months was a risk factor for severe outcome and longer hospitalization time.26 The presence of chronic pulmonary disease, mainly bronchopulmonary dysplasia, is related to the greater severity of AVB.21 and 35 Infants with bronchopulmonary dysplasia have a 6.7-fold risk of death from AVB when compared to infants without this condition.36 The presence of congenital heart disease is associated with increased severity of AVB.21 A recent study found that the length of hospitalization was higher in children who had congenital heart disease (6 versus 5 days; p < 0.0001), 29 and a retrospective study of 764 hospitalized patients with AVB showed that the presence of congenital heart disease was associated with a 50% longer length of hospital stay than in children without heart disease.