The Effect Of 60% Oxygen Inhalation On Oxygenation And Lung Injury During One-lung Ventilation

Aim:There is no standard method to establish a right one-lung ventilation(OLV)model in rabbits.In the present study,a novel method is proposed to compare with two other methods.Method:After 0.5 h of baseline two-lung ventilation(TLV),40 rabbits were randomly divided into four groups:sham group(TLV for 3 h as a contrast)(group C),deep intubation group(group 01),clamp group(group 02)and blocker group(deeply intubate the self-made bronchial blocker into the left main bronchus,the novel method)(group 03).At TO(before OLV)、T1(OLV 10 min)、T2(OLV 30 min)、T3(OLV 1h)、T4(OLV 2h)、T5(OLV 3h),four groups were compared using a number of variables:Oxygenation by arterial blood gas analysis;airway pressure;circulation by heart rate(HR),mean arterial pressure(MAP);lung injury by histopathology.And three OLV groups were compared with success rate,time,and blood loss of modeling.Result:The first-time and final success rate of modeling showed no differences among group 01,02,03.After excluding failed cases in building OLV,hypoxemia occurred 29%in group O1,29%in group 02,and 25%in group 03,there is no difference among three groups.At T1-5,arterial partial pressure of oxygen(PaO2)and arterial hemoglobin oxygen saturation(SaO2)were lower,peak pressure and lung injury scores were higher in group O1,O2,O3 than in group C(P<0.05).All these indexes showed no differences among group 01,02,03.During right-OLV modeling,less time was spent in group 03 than in group 01,02(P<0.05);More blood loss was observed in group 02 than in group 01,03(P<0.001).Conclusion:Compared with the present methods,deep intubation of the self-made bronchial blocker into the left main bronchus is reliable,easy and with little blood loss during establishing a right-OLV model in rabbits.Aim:Maintaining adequate oxygenation during one lung ventilation(OLV)requires high inspired oxygen fraction(FiO2).However,high FiO2 also causes inflammatory response and lung injury.Therefore,it remains as a great interest of clinicians and scientists to optimize the care of the patients undergoing OLV.The aim of this study is to determine and compare oxygenation,lung injury and inflammatory response during OLV in rabbits using FiO2 of 60%vs.100%.Method:After 30 min of TLV(two lung ventilation)as baseline,thirty rabbits were randomly assigned to three groups receiving mechanical ventilation of 3 hours:Sham group(group C),receiving TLV with 60%FiO2;100%FiO2 group(group 01),receiving OLV with 100%FiO2;and 60%FiO2 group(group 02),receiving OLV with 60%FiO2.Pulse oximetry was continuously monitored,and hypoxemia(SpO2<90%)rate of each group was recorded.Arterial blood gas analysis was intermittently conducted at TO(before OLV),T1(OLV 10 min),T2(OLV 30 min),T3(OLV 1h),T4(OLV 2h),T5(OLV 3h).Histopathology study of lung tissues was performed,inflammatory cytokines including myeloperoxidase(MPO),tumor necrosis factor-a(TNF-a),interleukin-6(IL-6),and the mRNA and protein of nuclear factor kappa B(NF-κB)p65 were determined.Result:Three of the 10 rabbits in group 02 suffered hypoxemia,while no rabbits in group 01 and group C suffered hypoxemia,there is no difference in hypoxemia incidence among three groups;At T1-5,partial pressure of oxygen(PaO2)was lower in group 01 and group 02 than in group C(P<0.05),while at T4 and T5,PaO2 was lower in group 02 than in group 01(P<0.05);At T5,acute Lung injury(ALI)score,MPO,TNF-a,IL-6,mRNA and protein of NF-κB p65 were higher in group 01 and group 02 than in group C(P<0.05),while these indexes were lower in group 02 than in group 01(P<0.05).Conclusion:In this animal research,if hypoxemia did not occur with 60%FiO2 during OLV,lung injury associated with high FiO2 can be minimized.However,30%rabbits suffered from hypoxemia with 60%FiO2.Aim:To investigate 60%inspired oxygen fraction(FiO2)applied for ventilated lung combined with oxygen(60%FiO2)blown to the non-ventilated lung on infection and oxygenation during right one lung ventilation(OLV)of thoracic surgery.Method:One hundred and twenty patients with American Society of Anesthesiology physical status 1 to 2 who were scheduled for left-thoractomy radical resection of esophageal or cardia cancer were enrolled in the study.The patients were randomly assigned to three groups according to different ventilation strategy during right-OLV,60%FiO2 for the ventilated lung without(group U,n=40)and with oxygen(3 L/min,60%FiO2)blown into the non-ventilated lung(group B,n=40),and 100%FiO2(group C,n=40)for the ventilated lung without oxygen blown into the non-ventilated lung.The primary end point was modified clinical pulmonary infection score(mCPIS)in seven days after operation and TNF-a,IL-6 concentration at TO(before anesthesia),T4(2h of OLV,and T6(24h after the operation).The secondary end point was oxygenation including oxygen arterial pressure(PaO2),arterial hemoglobin oxygen saturation(SaO2),and pulse oximetry(SpO2)at T0,T1(before OLV),T2(30 min of OLV),T3(1h of OLV),T4,T5(30 min after returning to two lung ventilation),and T6.Result:Within seven days after the operation,mCPIS was lower in group U and group B(p<0.05)than in group C.At T4 and T6,TNF-a 和 IL-6 were lower in group U and group B than in group C(p<0.05),there is no difference between group U and group B.Hypoxemia occurred in 4 patients(10%)of group U,while no hypoxemia occurred in patients of group B and group C,the incidence of hypoxemia was much lower in group B and group C than in group U(p<0.05).At T2,T3,T4,PaO2 and SaO2 were lower both in group U and B than in group C(p<0.05).At T2,T3,T4,SpO2 was lower in group U than in group C(p<0.05).At T3,SpO2 was lower in group B than in group C(p<0.05).Conclusion:60%FiO2 for ventilated lung combined with blown into the non-ventilated lung was accompanied with less inflammatory response,lower mCPIS compared with 100%FiO2,and less hypoxemia rate,compared with 60%FiO2 for ventilated lung without oxygen blown into the non-ventilated lung.Aim:The "double-edged sword" character of oxygen makes inspired oxygen fraction(FiO2)a very important and controversial issue.Both hyperoxia and hypoxia should be avoided.Hypoxemia is easily diagnosed with well-established criterion.However,damage from hyperoxia has not been paid enough attention to.We did this survey to analyze how anesthesiologists understand and apply FiO2 for mechanically ventilated patients.Method:A structured multi-choice questionnaire of anesthesiologists was conducted during a meeting at 30～31 Oct,2015.Result:Survey invitations were provided to 259 anesthesiologists who registered to attend the meeting on the spot.248 responses were received(96%).Excluding 6 partial responses,finally 242 full responses were received and analyzed(93%).31%of the respondents sometimes cared about FiO2,while 68%of the respondents reported highly concern about FiO2.During mechanical ventilation under general anesthesia,888%of the respondents considered higher than 60%as the upper safety limit of FiO2,and 5%took higher than 60%as the lower safety limit of FiO2,while 52%applied higher than 60%FiO2 clinically.During one lung ventilation(OLV),94%of the respondents considered higher than 60%as the upper safety limit of FiO2,and 21%took higher than 60%as the lower safety limit of FiO2,while 76%applied higher than 60%FiO2 clinically.19%of the respondents’ hospitals had no or few anesthesia machines which could set different FiO2,while 29%of the respondents’hospitals had no or few monitors which could show the value of FiO2.Conclusion:Anesthesiologists accustomed to deliver excess oxygen to the patients during mechanical ventilation in Jiangsu province which is one of the most developed provinces of China.One reason might be that in anesthesiologists’ opinion,hypoxia seems a more serious problem,compared to hyperoxia.The other reason is insufficiency of equipments which could set different FiO2 and display the value.Further evaluation of the administration of oxygen therapy,possible impact on mechanically ventilated patients and attention from senior officials are expected.