RESUMO
Objective:To evaluate the effect of apneic oxygen insufflation (AOI) on phenotypic transformation of alveolar macrophage (AM) in the non-ventilated lung during one-lung ventilation (OLV).Methods:A total of 60 patients of either sex, aged 40-64 yr, weighing 45-85 kg, undergoing elective thoracoscopic lobectomy, were recruited and divided into 2 groups using a computer-generated table of random numbers: test group and control group, with 30 cases in each group.At the beginning of OLV, the non-ventilated lung received 3 L/min of AOI in test group and no AOI in control group.Radial artery blood samples were collected for blood gas analysis before operation, immediately after anesthesia induction, 30 min, 1 h and 2 h after the start of OLV, and oxygenation index (OI) was calculated.The resected normal lung tissues around the lung lobe were excised at 2 h after the start of OLV for microscopic examination of the pathological changes after HE staining, and the lung injury score was assessed.Bronchoalveolar lavage fluid (BALF) was collected at 2 h after the start of OLV, AM was sorted by flow cytometry, and the apoptotic rate was calculated.The levels of intracellular Ca 2+ and reactive oxygen species (ROS, a marker of M1 AM phenotype) in cells were determined.The concentrations of M1 phenotype AM markers inducible nitric oxide synthase (iNOS), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) and of M2 phenotype AM markers arginase 1 (Arg-1) and interleukin 10 (IL-10) in BALF were measured by enzyme-linked immunosorbent assay. Results:Compared with control group, SpO 2, PaO 2 and OI were significantly increased, PaCO 2 and lung injury score were decreased, the survival rate of AM was increased, the apoptotic rate in the early and late stages was decreased, the concentrations of iNOS, IL-6 and TNF-α in BALF were decreased, and the concentrations of Arg-1 and IL-10 in BALF were increased, the level of ROS in AM was decreased, and the level of Ca 2+ in AM was increased in test group ( P<0.05). Conclusions:The mechanism by which implementing AOI in the non-ventilated lung reduces lung injury may be related to promotion of transformation of AM from M1 phenotype to M2 phenotype and inhibition of inflammatory responses during OLV in the patients undergoing thoracoscopic lobectomy.
RESUMO
Objective To evaluate the protective effect of apneic oxygen insufflation on the operated lung of patients undergoing one-lung ventilation (OLV).Methods Fifty-four American Society of Anesthesiologists physical status Ⅱ or Ⅲ patients of both sexes,aged 50-75 yr,scheduled for elective pulmonary tumorectomy,were divided into 2 groups using a random number table method:conventional group (group C,n=27) and apneic oxygen insufflation group (group A,n=27).The patients were intubated with a double-lumen tube after induction of anesthesia.Apneic oxygen insufflation was performed on the operated lung immediately after OLV by continuously administrating oxygen at 5 L/min with inspiratory oxygen fraction of 100％.Blood samples were taken from the radial artery at 1 min before OLV (T1) and 3 and 33 min after OLV (T2,3) for blood gas analysis,pulmonary oxygenation index and intrapulmonary shunt rate were calculated,and the occurrence of oxygen index less than 200 and 300 mmHg was recorded.Blood samples of the internal jugular vein were collected to detect the concentrations of surfactant protein B (SPB) and surfactant protein C (SP-C) in serum.The lung on the operated side was lavaged at T3,and the broncho-alveolar lavage fluid was collected for determination of the concentrations of SP-B and SP-C by enzyme-linked immunosorbent assay.Results Compared with group C,the oxygenation index was significantly increased at T2,3,the intrapulmonary shunt rate was decreased,the concentrations of SP-B and SPC in serum were decreased,and the concentrations of SP-B and SP-C in broncho-alveolar lavage fluid were increased in group A (P＜0.05).Conclusion Giving apneic oxygen insufflation 5 L/min to the operated lung during OLV can reduce the damage to the operated lung.