SpO2/FiO2 ratio: a prognostic marker for influenza patients

Vrinda Sahasrabhojney, Prasad D. Game, Dipti Chand, Vinay Meshram, Mahesh Kharade, Rahul Deotale


Background: The objective of the study was to study the utility of SpO2 /FiO2 ratio for monitoring and predicting the outcome of   H1N1 positive patients of category C.

Methods: This study is a hospital based observational study done at Government Medical College, Nagpur, Maharashtra, India from 14th January to 15th April 2015.  In this study, 156 H1N1 positive patients of category C were included.

Results: 156 Patients were included. 96 were female and 60 were male patients. SpO2/FiO2 ratio was calculated on day one and values were used to divide patients into 5 groups. Highest mortality (70%) is seen in a group with SpO2/FiO2 ratio < 150. SpO2/FiO2 ratio progressively dropped in patients who died. SpO2/FiO2 ratio gradually improved in patients who survived.

Conclusions: SpO2/FiO2 ratio on day 1 can be used as a prognostic marker in H1N1 positive patients. SpO2/FiO2 ratio was found to be a reliable marker to monitor the patients.


SpO2/FiO2 ratio, H1N1, Influenza, Prognostic marker

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