title: Prevalence and prediction of hypoxemia in children with respiratory infections in the Peruvian Andes.
abstract: To determine the effect of respiratory infections on oxyhemoglobin saturation in a high-altitude population, we recorded clinical signs, oxyhemoglobin saturation determined by pulse oximetry, and findings on radiographs of the chest of 423 children with acute respiratory infections; the children were living at an altitude of 3750 m in the Peruvian Andes. We defined hypoxemia as an oxyhemoglobin saturation value greater than 2 SD below the mean value for 153 well children in this population. Eighty-three percent of children with clinical bronchopneumonia, but only 10% of children with upper respiratory tract infection, had hypoxemia (p less than 0.001). Compared with previous studies of children living at lower altitudes, the presence of tachypnea was relatively nonspecific as a predictor of radiographically determined pneumonia or of hypoxemia, especially in infants. A history of rapid breathing was 74% sensitive and 64% specific in the prediction of hypoxemia, and performed as well as a standard World Health Organization case management algorithm in the prediction of radiographic pneumonia or hypoxemia. Radiographic pneumonia was not a sensitive predictor of hypoxemia or clinically severe illness. In contrast, the presence of hypoxemia was a useful predictor of radiographic pneumonia, with both sensitivity and specificity of 75% in infants. We conclude that acute lower respiratory tract infection in children living at high altitude is frequently associated with hypoxemia, and that oxygen should be administered to children with a diagnosis of pneumonia in these regions. Case management algorithms developed in low-altitude regions may have to be modified for high-altitude settings. In this setting, pulse oximetry is a good predictor of pneumonia. Because pulse oximetry is more objective and cheaper than radiography, its role as a clinical and investigative tool merits further exploration.
authors.affiliation: Johns Hopkins University School of Medicine, Departments of International Health, Baltimore, Maryland.
authors.forename: D S
authors.initials: DS
authors.lastname: Reuland
authors.forename: M C
authors.initials: MC
authors.lastname: Steinhoff
authors.forename: R H
authors.initials: RH
authors.lastname: Gilman
authors.forename: M
authors.initials: M
authors.lastname: Bara
authors.forename: E G
authors.initials: EG
authors.lastname: Olivares
authors.forename: A
authors.initials: A
authors.lastname: Jabra
authors.forename: D
authors.initials: D
authors.lastname: Finkelstein
mesh_terms: D000208:Acute Disease; D000531:Altitude; D002675:Child, Preschool; D006801:Humans; D000860:Hypoxia / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology; D007223:Infant; D010568:Peru / Q000453:epidemiology; D015995:Prevalence; D011652:Pulmonary Circulation / Q000502:physiology; D012016:Reference Values; D012129:Respiratory Function Tests; D012141:Respiratory Tract Infections / Q000150:complications* / Q000453:epidemiology