Hypoxaemia among children with severe or very severe pneumonia at Kenyatta National Hospital

Abstract

Background: Pneumonia is the leading cause of childhood morbidity and mortality' in developing countries with hvpoxaemia as the most common and fatal complication. Oxygen therapy is an important intervention for children with hypoxaemia. In many settings in Kenya, clinical signs are used to identify children who require oxygen. The Government of Kenya (GoK) has provided criteria for oxygen therapy. It states that oxygen should be administered to a child with any of these signs: cyanosis, inability to drink/breastfeed, impaired consciousness, grunting or head nodding. While there is data exploring the utility of clinical signs to identify hypoxaemic children, this GoK ‘decision rule' has never been evaluated. There is paucity of information on some of the signs included in the GoK criteria and little local information on the prevalence of hypoxaemia among children with severe forms of pneumonia. Objectives: To determine the prevalence of hypoxaemia and evaluate the sensitivity and specificity of the GoK criteria for oxygen therapy for children with severe or very severe pneumonia admitted at Kenyatta National Hospital, Nairobi, Kenya, to determine whether Human Immunodeficiency Virus (HIV) infection was a risk factor for hypoxaemia and to evaluate the association between hypoxaemia and short term inpatient mortality. Methodology: This was a hospital based short longitudinal survey. We enrolled 343 children aged two to 59 months, assessed them for presence of clinical signs associated with hypoxaemia, measured their arterial oxygen saturation using a portable hand held pulse oximeter and had them tested for HIV infection. We followed up the children for five days to determine mortality outcome. Results: Prevalence of hypoxaemia was 50.7% in the study population. Stratified by severity, 39.7% and 59.4% of children with severe and very severe pneumonia respectively were hypoxaemic. Cyanosis and grunting were found to be independent predictors of hypoxaemia. The GoK criteria had a sensitivity of 65.5% and a specificity of 53.8% for detecting children who required oxygen therapy. Thirty one children (9.0%) were HIV infected. Oxygen saturation of <85% was associated with increased mortality (OR 3.3. 95% CI= 1.5 to 7.1, P=0.005). Conclusions: Hypoxaemia is frequent, occurring in 50.7% of children hospitalized with severe or very severe pneumonia at Kenyatta National Hospital. The GoK criteria for oxygen therapy have a low sensitivity (65.5%) and specificity (53.8%) for predicting hypoxaemia. Severe hypoxaemia (Sp02 <85%) is associated with a 3.3 fold increased mortality. Recommendations: The Government of Kenya should consider promoting the use of pulse oximetry in all public hospitals to detect hypoxaemia. A cost-benefit study on the use of pulse oximeters vis-a-vis continued use of clinical signs to determine which children require oxygen therapy should be carried out.