CLINICAL PREDICTORS OF ACUTE RADIOLOGICAL PNEUMONIA AND HYPOXEMIA AT HIGH-ALTITUDE

Fast breathing has been recommended as a predictor of childhood pneumo nia. Children living at high altitude, however, may breathe faster in response to the lower oxygen partial pressure, which may change the ac curacy of prediction of a high respiratory rate. To assess the usefuln ess of clinical manifestations in the diagnosis of radiological pneumo nia or hypoxaemia, or both, at high altitude (2640 m above sea level), 200 children aged 7 days to 36 months presenting to an urban emergenc y room with cough lasting less than seven days were studied. Parents w ere interviewed and the children evaluated using standard forms. The r esults of chest radiographs and pulse oximetry obtained after clinical examination were interpreted blind. Radiological pneumonia and haemog lobin oxygen saturation < 88% were used as 'gold standards', One hundr ed and thirty (65%) and 125 (63%) children had radiological pneumonia and hypoxaemia respectively. Crepitations and decreased breath sounds were statistically associated with pneumonia, and rapid breathing as p erceived by the child's mother, chest retractions, nasal flaring, and crepitations with hypoxaemia. The best single predictor of the presenc e of pneumonia is a high respiratory rate, although the results are no t as good as those reported by other studies. A respiratory rate great er than or equal to 50/minute had good sensitivity (76%) and specifici ty (71%) for hypoxaemia in infants. Hypoxaemia had a good sensitivity and specificity for pneumonia mainly in infants (83% and 73%, respecti vely). Logistic regression analysis showed that decreased or increased respiratory sounds and crepitations were associated with pneumonia, a nd that hypoxaemia is the best predictor when auscultatory findings ar e excluded. These suggest that some clinical predictors appear to be l ess accurate in Bogota than in places at lower altitude, and that puls e oximetry can be used for predicting pneumonia.