Introduction: The current global pandemic of the coronavirus severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) is the world’s most critical ongoing healthcare problem,with 8.2% of critically ill patients developing acute respiratory distress syndrome (ARDS) and requiring intensive care unit (ICU) admission. Our study aimed to correlate the computed tomography severity score (CTSS) of the patient at the time of diagnosis with spirometry, 6-minute walk test and breath holding time at 12 weeks after discharge, to determine the nature of the residual pulmonary dysfunction and if CT severity was a predictor of poor lung function post recovery.

Aim: To correlate the CT severity score of the patient with spirometry,6-minute walk test and breath holding time to assess the nature of the residual pulmonary dysfunction and to determine if CT severity was a predictor of poor lung function post recovery.

Methods: Ambi-directional single center study conducted in Saveetha Medical College Hospital.  Patients over the age of 18 with a positive Covid-19 RTPCR report and a CTSS >1 were enrolled into the study after systematic random sampling. PFT, 6-minute walk test and Breath Holding Time were done at a period of 12 weeks post discharge.

Results:  50 patients were enrolled in the study; Mean CT severity score was: 11.48. 26% of the patients had more than 50% lung involvement on CT. There was significant negative correlation observed between FVC and Severity score (r=-0.366, p=.009) and significant negative correlation observed between Breath holding and Severity score (r= -0.339, p=.016) while there was no significant correlation between 6-minute walk test and the CT Severity score

Conclusion: Patients with a significant lung involvement during SARS-COV-2 infection showed impaired pulmonary function test parameters in the form of a reduced FVC and breath holding time, 3 months following diagnosis. Long-term follow up along with pulmonary rehabilitation is crucial to achieve near complete respiratory recovery.

Keywords: Post-COVID, Long COVID, PFT, CT severity score