Effects Of Sevoflurane Pretreatment On Intrapulmonary Shunt And Oxygenation In Patients With One Lung Ventilation

Objective:To explore the effects of sevoflurane pretreatment on intrapulmonary shunt and oxygenation in patients with one-lung ventilation.Data method:With the approval of the Ethics Committee,60 patients with esophageal cancer surgery and lung cancer surgery who were scheduled to undergo elective surgery from June 2018 to December 2019 Thoracic surgery in our hospital were selected as the research subjects,including 32 males and 28 females,24 patients undergoing esophageal surgery and 36 patients with lobectomy.ASA grade I to II,age 40 to 60 years,BMI value <28KG/M2;randomly divided into 2 groups of control group（full vein group,group P）and observation group（sevoflurane pretreatment group,group S）,30 cases in each group.Both groups of patients were under general anesthesia,and the methods of anesthesia,anesthesia induction,and anesthesia maintenance were the same.After induction of general anesthesia,the appropriate type of double-lumen bronchus catheter was inserted according to the location of the surgical department.After positioning by fiber bronchoscope,the ventilator-related parameters were set: tidal volume 8m L/kg,ventilation frequency 12 times/min,and pure oxygen（oxygen flow 2L/min）,respiration ratio 1: 2.After one-lung ventilation,the ventilator parameters were set to a tidal volume of 6ml/kg and a ventilation frequency of 12 times/min.In the observation group（sevoflurane pretreatment group,group S）,inhalation of sevoflurane at a concentration of 2%-3% was completed immediately after tracheal intubation.After 30 min,inhalation of sevoflurane was stopped.Intraoperative anesthesia maintenance: Propofol 6¹2 mg /（kg · min）and remifentanil 0.1⁰.2ug /（kg · min）were used for continuous pumping until the end of surgery in both groups.Cis-atracurium wasintermittently administered,and end-expiratory carbon dioxide（PETCO₂）was maintained at35-45 mm Hg.The anesthesia depth was monitored using the bispectral index（BIS）of the brain,and the BIS was maintained at 40-60.Observation indicators: continuous monitoring of non-invasive blood pressure（BP）,ambulatory blood pressure（ABP）,mean arterial pressure（MAP）,heart rate（HR）,electrocardiogram（ECG）,pulse oxygen saturation（Sp O₂）,and bispectral index（BIS）End-respiratory carbon dioxide（Pet CO₂）,airway plateau pressure（Pplat）,airway peak pressure（Ppeak）;record the operation time,one-lung ventilation time,wake-up time,and extubation time of the two groups respectively;Record the operation time,one-lung ventilation time,wake-up time,and extubation time of the two groups separately;record T1（after induction）,T2（30 minutes after one-lung ventilation）,T3（one-lung ventilation for 60 minutes）,T4（after surgery）to measure arterial and venous blood gas at different time points,According to the formula Qs/Qt =（Cc O₂-Ca O₂）/（Cc O₂-Cv O₂）× 100%;calculate the intrapulmonary shunt rate（Qs/Qt）;monitor the patient’s arterial oxygen pressure（Pa O₂）,according to the formula（OI = Pa O₂/Fi O₂）Calculate the OI of the patient.All the data in this study were processed using IBM SPSS Statistics 26.0 statistical analysis software.Results:（1）There was no significant difference in clinical data between the two groups in age,gender,ASA classification,tumor classification,height,and BMI value（P> 0.05）,and they were comparable.（2）There was no significant difference in the operation time,one-lung ventilation time,wake-up time,and extubation time between the two groups of patients（P>0.05）.（3）Compared with T1,at the T2 time point,the arterial blood oxygen partial pressure（PAO₂）and oxygenation index of both groups decreased（P<0.05）,and the lung shunt rate（Qs/Qt）of the two groups of patients increased significantly（P<0.05）;At the time points of T2 and T3,the lung shunt rate（Qs/Qt）of the sevoflurane pretreatment group was reduced compared with the total intravenous group（P<0.05）.（4）There was a difference in oxygenation between the two groups,and there was no statistical significance（P>0.05）.Conclusions:Pretreatment with sevoflurane can reduce intrapulmonary shunt during one-lung ventilation and has no effect on the patient’s recovery time and extubation time...