Clinical predictors ofacuteradiological pneumonia andhypoxaemia athighaltitude

Fastbreathing hasbeenrecommended as a predictor of childhood pneumonia. Children living athighaltitude, however, may breathefaster inresponsetothe loweroxygenpartial pressure, whichmay changetheaccuracyofprediction ofa highrespiratory rate.To assesstheusefulness ofclinical manifestations inthe diagnosis ofradiological pneumonia or hypoxaemia, or both,athighaltitude (2640 m abovesealevel), 200children aged 7 daysto36monthspresenting to an urbanemergency roomwithcoughlasting lessthansevendayswerestudied. Parents were interviewed and the children evaluated usingstandardforms.The results ofchestradiographs andpulse oximetry obtained after clinical examinationwereinterpreted blind. Radiological pneumoniaand haemoglobin oxygen saturation <88% were usedas 'gold standards'. Onehundredandthirty (65%) and125(63%)children hadradiological pneumonia andhypoxaemia respectively. Crepitations anddecreased breath sounds werestatistically associated withpneumonia,andrapidbreathing asperceived by thechild's mother,chestretractions, nasalflaring, and crepitations with hypoxaemia. Thebestsingle predictor of thepresence ofpneumonia isahighrespiratory rate, although theresults arenot asgoodasthosereported byotherstudies. A respiratory rate¢50/minute hadgood sensitivity (76%)andspecificity (71%)for hypoxaemia ininfants. Hypoxaemia hada goodsensitivity andspecificity forpneumoniamainlyininfants (83%and73%, respectively). Logistic regression analysis showedthatdecreased or increased respiratory soundsandcrepitations were associated withpneumonia, and that hypoxaemia isthebestpredictor when auscultatory findings areexcluded. These results suggestthatsome clinical predictors appearto be lessaccuratein Bogotathaninplaces atloweraltitude, andthatpulseoximetry canbeusedfor predicting pneumonia. (Arch DisChild 1994; 71:323-327)