RAPID PRE-OXYGENATION USING HIGHFLOW OXYGEN, COMPARITIVE STUDY BETWEEN TIDAL VOLUME BREATHING AND DEEP BREATHING

Abstract

Background: Rapid and effective pre-oxygenation is crucial before endotracheal intubation during general anaesthesia in the patients posted for elective surgery. Insufficient arterial oxy-haemoglobin levels can lead to severe complications, including hypoxic brain injury, dysrhythmias, and even death. High-flow oxygen systems, which enhance deep breathing (DB) by delivering oxygen(O2) in excess of peak inspiratory flow, may provide advantages over tidal volume breathing (TVB) in pre-oxygenation. “Aim of this study is to compare the efficacy of tidal volume breathing versus deep breathing for rapid pre-oxygenation at different oxygen flow rates of 10 L/min and 15 L/min by assessing the time and number of breaths required to reach an end-tidal oxygen concentration (EtO2) of 0.9.” Materials and Methods: This comparative study involved 40 patients posted for elective surgeries under general anaesthesia, divided into 4 groups “T10 (TVB with 10 L/min), D10 (DB with 10 L/min), T15 (TVB with 15 L/min), and D15 (DB with 15 L/min).” Participants included adults aged 18-59 years with ASA grades 1 and 2. Exclusion criteria includes a BMI more than 30 kg/m², chronic smoking, pregnancy, and anticipated difficult airway. Standardized preoperative assessments and routine investigations were performed. The time taken and the number of breaths needed to achieve an EtO2 of 0.9 were recorded and analysed using ANOVA and chi square tests, with a p value of <0.05 considered significant. Results: The study revealed significant differences in pre-oxygenation efficacy among the groups. Group D10 (DB with 10 L/min) reached an EtO2 of 0.9 in the shortest time (74.4±10.2 seconds), followed by Group D15 (DB with 15 L/min) at 74.6±9.8 seconds. Groups T10 and T15 (TVB) took longer to achieve the target EtO2. Moreover, Group D10 required the fewest XIII breaths (10.2±1.9) to reach the target EtO2, followed by Group D15 (13.0±2.7), while both TVB groups needed more breaths. Conclusion: Deep breathing with high-flow oxygen significantly enhances the speed and efficiency of pre-oxygenation compared to tidal volume breathing. DB at a 10 L/min flow rate is particularly effective, achieving the target EtO2 more rapidly and with fewer breaths, indicating its superiority for rapid pre-oxygenation in clinical practice.