European Journal of Cardiovascular Medicine

Preoxygenation is the administration of oxygen former to the induction of anesthesia, it permits a safety shield during stages of apnoea and hypoventilation and it also prolongs the time period of safe apnoea. During anesthesia, oxygenation chiefly depends on alveolar ventilation, distribution of ventilation/perfusion ratio, and consumption of O2. The highest preoxygenation is attained when the alveolar and arterial tissues and venous compartments are all occupied with oxygen. During induction of general anesthesia in patients, the usage of 100% oxygen has become standard practice, although preoxygenation was primarily proposed as an optional precautionary measure. Oxygenation techniques is a safe intubation technique for the majority of the surgical patients.  Materials And Methods: The study was randomized control study with duration of 11 months. The study was conducted by the Department of Anesthesiology at Shadan Institute of Medical Sciences (SIMS), Hyderabad. The patients were explained regarding the study, the procedure and complications of arterial cannulation and the informed consent form was collected from all participating patients before the commencement of the study. 60 patients in the age group between 20-60 years of age and of either gender, belonging to ASA grade I-II scheduled for elective surgeries under general anesthesia, were included in the study and divided into two equal groups (Group a and Group b) of 30 each.  ABG samples were obtained before and after preoxygenation. All patients were instructed regarding the procedure of preoxygenation and procedure for obtaining an arterial blood sample. Results: In group A (100% oxygen) the mean value for age (20-60yrs) is 1.50±0.82, and in group B (60% oxygen) it is found to be 1.52±0.80. In group A (100% oxygen) the mean value for gender is 1.45±0.45, and in group B (60% oxygen) it is found to be 1.43±0.50. BMI (mg/m2) was measured and in group A (100% oxygen) the mean value is 1.43±0.77 and in group B (60% oxygen), it is 1.37±0.76. Comparison of partial pressure of oxygen (PaO2) in the study groups was done, group A (100% oxygen) showed 99.03±6.10 at PaO2 (0 mins) and 100±0.00 at PaO2 (3 mins). Group B (60% oxygen) showed 99.05±5.67 at PaO2 (0 mins) and 100±0.00 at PaO2 (3 mins). Statistical significance (p<0.001*) was found between group A (100% oxygen) and group B (60% oxygen). Comparison of level of oxygen saturation (SpO2) in the study groups was done, group A (100% oxygen) showed 98.50±0.60 at SpO2 (0 mins) and 100±0.00 at SpO2 (3 mins). Group B (60% oxygen) showed 98.50±0.51 at SpO2 (0 mins) and 100±0.00 at SpO2 (3 mins).  Conclusion: To be more apt, currently there is no clinical evidence claiming the increase in incidence of hypoxia and its complications with a lower FiO2. The findings of this current study performed over 60 patients could be reliable fundamental evidence for future references. Furthermore, the conclusions of our study could widen up the horizon for the anesthesiologists during times of oxygen scarcity.