Oxygen supply and consumption in patients undergoing thoracic surgery under spontaneous breathing during anesthetic period

Abstract

Objective To compare the relevant indexes of oxygen supply and oxygen consumption in tracheal intubation group and spontaneous respiration group, and to determine whether patients with spontaneous respiration during operation could maintain the balance of oxygen supply and consumption. Methods Forty-one patients who fulfilled the inclusion criteria were included in the study between January 2017 and March 2018. All patients were divided into the tracheal intubation group (group A, n=20) and spontaneous respiration group (group B, n=21) . After anesthesia induction, orotracheal intubation with a double-lumen tube was performed for ventilation in group A. Spontaneous breathing was retained in group B by laryngeal mask airway placement after anesthesia induction, and the anesthesia machine was used for oxygen inhalation (inhaled oxygen concentration: 29%) . The hemoglobin (Hb) , arterial oxygen saturation (SaO2) , mixed venous oxygen saturation (ScvO2) , venous lactic acid (Lac) , arteriovenous oxygen content (Ca-vO2) , oxygenation index (OI) , oxygen supply index (DO2I) , oxygen consumption index (VO2I) and oxygen extraction rate (O2ER) at 1 min before thoracotomy (T0) ; at 5 min (T1) , 15 min (T2) , 30 min (T3) , 60 min (T4) after thoracotomy; during sternal closure (T5) ; and at 15 min after sternal closure (T6) were compared between the two groups. Results In Group B, the concentration of Hb was >90 g/L and SaO2 was above 90% at each time point. ScvO2 at T1-T3 and T5 in group B significantly increased compared with those in group A (P 0.05) . There were no statistically significant differences in Lac, DO2I, VO2I and O2ER at T1-T6 and T0 in group B (P>0.05) . DO2I had positive correlation with VO2I (r=0.72, P<0.01) . Conclusion Under the premise of sufficient oxygen supply in the two groups, the oxygen consumption in group A is lower than that in group B. thoracic surgery under spontaneous breathing during anesthetic period. The balance of oxygen supply and consumption in group A undergoing thoracic surgery during anesthetic period may be maintained. Key words: Spontaneous breathing; Thoracic surgery; Anesthesia; Oxygen supply; Oxygen consumption