Prevalence of undiagnosed hypoxemia in adults and children in an under-resourced district hospital in Zambia

Abstract

Background: In adequately resourced clinical environments, diagnosis of hypoxemia via pulse oximetry is routine. Unfortunately, pulse oximetry is rarely utilized in under-resourced hospitals in developing countries.

Aim: The prevalence of undiagnosed hypoxemia among adults and children with illnesses other than pneumonia in these environments remains poorly described.

Methods: This cross-sectional analysis of the prevalence of hypoxemia was conducted in Kapiri Mposhi, Zambia, at the 60-bed District Hospital, which serves a population of 320,000. The resting room air oxygen saturations of two consecutive samples of all adult and pediatric inpatients were measured in December 2008 and March 2009 using handheld pulse oximetry. Hypoxemia was defined as resting room air SpO(2) less than 90%.

Results: A total of 192 patients were enrolled: 68 young children (<5 years old), 15 older children (5-17 years old), and 109 adults (≥18 years old). Five young children (7%), 0 older children (0%), and 10 adults (9%) were hypoxemic. No hypoxemic patients were receiving oxygen therapy at the time of diagnosis. Pneumonia, tuberculosis, and malnutrition were the most common conditions among those with hypoxemia. Oximetry data changed clinical management in all observed cases of hypoxemia and several cases of normoxemia, leading to application of supplemental oxygen, initiation of further diagnostic testing, prolongation of inpatient stay, or expedited discharge home.

Conclusions: Undiagnosed hypoxemia is present among inpatients at this district hospital in rural Zambia with high prevalence in both adults and young children. These results support routine screening for hypoxemia in similar facilities in both age groups. Further investigation is warranted into the clinical impact and cost-effectiveness of pulse oximetry, provision of oxygen concentrators, and training on their use in developing countries.

Keywords: Developing countries; Hypoxemia; Pediatrics; Public health; Pulse-oximetry; Respiratory infections.

Fig. 1

Histogram of inpatient resting room air oxygen saturation levels at Kapiri District Hospital (all ages)

Fig. 2

Prevalence of hypoxemia (resting room air SpO₂ < 90%) at Kapiri District Hospital by age group with 95% confidence intervals of proportions. *Denotes statistical significance for prevalence ≥1% via one-sided, one-sample test of proportion at α = 0.05. **Denotes statistical significance for difference in distribution of oxygen saturation levels among the three groups via Kruskal-Wallis equality-of-populations rank test at α = 0.05