Usage of High Flow Nasal Cannula in Preventing Desaturations in Elderly Patients Going for Lower Limb Surgeries

Comparing Intraoperative High Flow Nasal Cannula Therapy and Convetional Oxygen Therapy in Preventing Perioperative Hypoxaemia In Elderly Patients Undergoing Orthopaedic Surgery: A Randomized Controlled Study

To study the effect of high flow nasal cannula in comparisons with nasoprong used intraoperatively in patients oxygenation status

To observe the effect of high flow nasal cannula used intraoperatively compared to normal oxygen therapy (nasoprong) at a same fraction of inspired oxygen (FiO2) in elderly patients who are going for orthopaedic surgeries under central neuraxial block.

oxygenation will be access with intermittent blood gas. atelectasis will be access via chest x-ray , compared to a baseline chest x-ray, validated by a blinded radiologist

Inclusion Criteria:

1. American Society of Anesthesiologists (ASA) I, II or III patients.
2. Patients age 60 years and above
3. Patients scheduled for total knee replacement therapy and hip surgeries under central neuraxial block under the elective and emergency list.

Exclusion Criteria:

1. Patients with pre-operative spO2<94%
2. Patients delirious or demented / unable to give consent.
3. Patients with pre-existing pneumonia (defined as the initiation of antibiotics for suspected infection with one or more of the following: new or changed sputum; new or changed lung opacities; fever; white blood cell count >12 × 109 litre-1 )15
4. BMI ≥35