Post Covid SPO2 fall & pulse increase.

My mother admitted for 10 days in Hospital as SPo2 falles and CT score 10/25 doctor tells might be fibrosis developed . Now it's 12 days from Discharge and 25 days from Positive On Oxygen @0.5 ltr/min but Spo2 level not Maintain a d sudden increase in pulse . Sop2 during sleep with Oxygen 94- 97 Spo2 during sleep without Oxygen goes upto 85 Spo2 when not slept with oxygen 94-98 (on bed) Spo2 when not slept without oxygen 91-95(onBed) During movement on Bed Or side Change  Fall in SPo2 up to 85-87 and sudden spike in Pulse from 75 to 125/130 CRP  - 12 mg/dl D Dimer - 0.25 ug/ml 3 day earlier Now Medicine Nintedanib 150 mg -BD Apixaban 2.5 mg -BD Vic C-OD Zincovit -OD Nebulization dolin&buducort BD Mucinac 600  - SOS