Tachypnea and Other Danger Signs vs Pulse Oximetry for Prediction of Hypoxia in Severe Pneumonia/Very Severe Disease.

OBJECTIVE: To compare the performance of respiratory rate and other clinical signs against pulse oximetry for predicting hypoxia in children with Severe pneumonia/Very severe disease as per Integrated Management of Neonatal and Childhood Illness (IMNCI) classification.

DESIGN: Cross-sectional study.

SETTING: Pediatric emergency department of a tertiary-care hospital in Delhi, India.

SUBJECTS: 112 hospitalized children (2 mo - 5 y) with Severe pneumonia/Very severe disease as per IMNCI classification.

METHODS: Respiratory rate was recorded at enrolment, along with other clinical signs and symptoms. Oxygen saturation (SpO2) was measured by a pulse oximeter. Clinical predictors of hypoxia (SpO2 <90%) and their combinations (index test) were evaluated for their sensitivity, specificity, positive predictive value and negative predictive value for diagnosis of hypoxia, against pulse oximetry (reference test).

RESULTS: Hypoxia was present in 57 (50.9%) children. Presence of tachypnea, head nodding, irritability, inability to drink/breastfeed, vomiting, and altered sensorium was significantly associated with hypoxia (P<0.05). Multiple logistic regression revealed that age-specific tachypnea (RR≥70/min for 2-12 mo, and RR ≥60/min for ≥12 mo), head nodding, and inability to drink/breastfeed were independent predictors for hypoxia with sensitivity of 70.2%, 50.9% and 75.4%, respectively; and specificity of 88.9%, 96.4%, and 90.9%, respectively. When all three predictors were used in conjunction, the sensitivity increased to 91.2% and specificity was 81.8%.

CONCLUSION: No single clinical sign can perform as well as pulse oximetry for predicting hypoxia in children with severe pneumonia. In settings where pulse oximetry is not available, combination of signs, age-specific tachypnea, head nodding, and inability to drink/breastfeeding has acceptable sensitivity and specificity.