Correlation Between Intraoperative End Tidal Carbon Dioxide Value And Post Operative Oxygen Requirement In Patients Under Going Spinal Anaesthesia With Opioid As An Additive Drug Observational Cross Sectional Study.

This is an observational cross-sectional study designed to evaluate the relationship between intraoperative end-tidal carbon dioxide Value levels and postoperative oxygen requirements in patients undergoing spinal anaesthesia with an opioid additive.

Spinal anaesthesia is commonly used for lower limb and lower abdominal surgeries. Intrathecal opioids enhance analgesia but may cause respiratory depression, leading to postoperative hypoxia. Monitoring intraoperative end-tidal carbon dioxide Value  provides an early indicator of ventilatory compromise, while postoperative oxygen requirement serves as a clinical marker of respiratory adequacy.

The study will be conducted in a tertiary care teaching hospital between August 2025 and January 2027, including 60 adult patients (ASA I–II, aged 18–65 years) scheduled for elective lower limb or lower abdominal surgeries under spinal anaesthesia with opioid additive.

Primary Objective: To evaluate the correlation between intraoperative end-tidal carbon dioxide Value  levels and postoperative oxygen requirement.

Secondary Objectives: To assess the requirement and duration of postoperative oxygen therapy and to analyze the relationship between intraoperative sedation and postoperative respiratory outcomes.

Intraoperative end-tidal carbon dioxide Value  will be monitored continuously using a sidestream capnograph, and postoperative oxygen saturation will be assessed for 24 hours in the Post Anaesthesia Care Unit. Supplemental oxygen will be provided if  Saturation falls below 92%.

The findings are expected to provide insights into predicting postoperative oxygen needs, enabling early identification of patients at risk of opioid-induced respiratory compromise and guiding safer perioperative management.