To describe the clinical characteristics of infants with acute viral bronchiolitis (AVB) and to assess the influence of oxygen desaturation time (DT) as a prognostic test to estimate the evolution of such patients.
We performed a cohort study with 111 hospitalized patients diagnosed with AVB receiving oxygen therapy through nasal prong. The outcomes were: length of admission, length of oxygen therapy and time elapsed to read 95% saturation in room air. A severity score was obtained twice a day based on clinical signs during the time when the patient required oxygen supplementation. After the supply of oxygen was interrupted, the time required for transcutaneous oxygen saturation decreased to 90% and 85%. The Chi2 test or Fisher's exact test were used to compare categorical variables. The t test or Mann-Whitney's test were used for numerical variables. Spearman's correlation was used to evaluate associations in continuous variables with asymmetric distribution.
Most patients (61.3%) were younger than 4 months. Patients with wheezing history (45%) were analyzed separately and had similar results to those of the group with AVB (p< or =0.05). Twenty-six patients (23%) had moderate or severe malnutrition. All patients were using bronchodilators; 20% were using systemic corticosteroids; and 47%, antibiotics. The median time of oxygen therapy required for a reading of 95% oxygen saturation in room air was 83 hours (IQI 55-128). The median of length of admission was 7 days (IQI 5-10.5). Little clinical variability was observed in the period studied. No significant correlations were found between the clinical scores, DT and the outcomes.
DT was not useful as an aid to assess AVB patients on oxygen therapy in this study. It is possible that this tool could have been more useful in patients with more clinical variability.