Zulkifli Amin1, Martin Winardi2
1Division of Respirology and Critical Care, Department of Internal Medicine,
Faculty of Medicine, Universitas Indonesia, Cipto Mangunkusumo Hospital, Indonesia 2Department of Internal Medicine, Faculty of Medicine,
Universitas Indonesia, Cipto Mangunkusumo Hospital, Indonesia

ABSTRACT
Background: Decreased oxygen supply due to acute physiological deterioration may increase mortality risk, particularly in critically ill patients with inadequacy to compensate such changes. The aim of the study was to evaluate peripheral oxygen saturation (SpO2) at admission in predicting mortality of emergency patients with critical conditions at Cipto Mangunkusumo Hospital (CMH), the national referral hospital in Indonesia. Methods: We performed a retrospective cohort study of emergency patients with critical conditions at Emergency department (ED), CMH from October to November 2012. SpO2 was meassured within 15 minutes after patients’ arrivals. Subjects were divided into two groups: group 1 consisted of subjects with SPO2 more or equal to 95% and subjects with SpO2 less than 95% were in group 2. Primary outcome measured was in-hospital mortality. Log-rank test was used to analyze survival between groups. Risk of in-hospital mortality was analyzed with Cox proportional hazard model.
Results: In-hospital mortality rate was observed in 69 (40.1%) from 172 patients. Patients with SpO2 less than 95% had a significantly lower survival rate (mean survival 21.3 vs 28.6 days, log-rank p = 0.011). The hazard ratio of mortality was 1.8 (95% CI 1.13 to 2.90) in patients whose SpO2 fell below 95%.
Conclusions: Peripheral oxygen saturation below 95% at admission was significantly associated with increased risk of in-hospital mortality. Given the ease of its measurement, SpO2 should be considered as a predictor of mortality in emergency patients with critical conditions.
Keywords: Peripheral oxygen saturation, critical conditions, emergency, mortality