One-lung Ventilation Group Research Articles

Two-lung ventilation with artificial pneumothorax on cerebral desaturation and early postoperative cognitive outcome: a randomized controlled trial.

The effect of two lung ventilation (TLV) with carbon dioxide artificial pneumothorax on cerebral desaturation and postoperative neurocognitive changes in elderly patients undergoing elective minimally invasive esophagectomy (MIE) is unclear. The first aim of this study was to compare the effect of TLV and one lung ventilation (OLV) on cerebral desaturation. The second aim was to assess changes in early postoperative cognitive outcomes of two ventilation methods. This prospective, randomized, controlled trial enrolled patients 65 and older scheduled for MIE. Patients were randomly assigned (1:1) to TLV group or OLV group. The primary outcome was the incidence of cerebral desaturation events (CDE). Secondary outcomes were the cumulative area under the curve of desaturation for decreases in regional cerebral oxygen saturation (rSO2) values below 20% relative to the baseline value (AUC.20) and the incidence of delayed neurocognitive recovery. Fifty-six patients were recruited between November 2019 and August 2020. TLV group had a lower incidence of CDE than OLV group [3 (10.71%) vs. 13 (48.14%), P = 0.002]. TLV group had a lower AUC.20 [0 (0-35.86) % min vs. 0 (0-0) % min, P = 0.007], and the incidence of delayed neurocognitive recovery [2 (7.4%) vs. 11 (40.7%), P = 0.009] than OLV group. Predictors of delayed neurocognitive recovery on postoperative day 7 were age (OR 1.676, 95% CI 1.122 to 2.505, P = 0.006) and AUC.20 (OR 1.059, 95% CI 1.025 to 1.094, P < 0.001). Compared to OLV, TLV had a lower incidence of CDE and delayed neurocognitive recovery in elderly patients undergoing MIE. The method of TLV combined with carbon dioxide artificial pneumothorax may be an option for these elderly patients. Chinese Clinical Trial Registry (identifier: ChiCTR1900027454).

Comparison of early postoperative pulmonary complications between two-lung ventilation with artificial pneumothorax and one-lung ventilation with bronchial blockade in patients undergoing minimally invasive esophagectomy: a retrospective propensity score-matched cohort study.

Two-lung ventilation (TLV) with artificial carbon dioxide (CO2) pneumothorax is used during the thoracoscopic phase of minimally invasive esophagectomy (MIE). However, the impact of TLV with artificial pneumothorax on postoperative pulmonary complications (PPCs) after MIE is unclear. This study aimed to compare the incidence of early PPCs between TLV with CO2 pneumothorax and one-lung ventilation (OLV) with bronchial blockade in patients undergoing MIE. Five hundred ninety-three patients with esophageal cancer who underwent elective MIE with two-field lymph node dissection were analyzed. Patients in the TLV group were intubated using a single-lumen endotracheal tube and underwent surgery using TLV with artificial CO2 pneumothorax. Patients in the OLV group underwent surgery using OLV with a bronchial blocker. Patient characteristics and intraoperative and PPC data were collected and analyzed. Propensity score matching (PSM) was performed to reduce confounding bias. The TLV and OLV group comprised 513 and 80 patients, respectively. PSM matched 197 TLV group and 73 OLV group patients. Incidence of pneumonia within the first 3 days of surgery was higher in the TLV group (11.7% vs. 4.1%) but the difference was not significant (P=0.06). The incidence of infiltrates on chest radiography was 36.0% in the TLV group and 28.8% in the OLV group (P=0.26). Incidence of other major PPCs requiring treatment and major non-pulmonary postoperative complications did not significantly differ between the groups. Length of hospital stay was significantly longer in the TLV group (13.0 vs. 11.0 days; P=0.03). Compared with OLV with bronchial blockade, TLV with CO2 pneumothorax did not reduce the incidence of early PPCs after MIE.

A randomized controlled trial of positive end-expiratory pressure on pulmonary oxygenation and biventricular function in esophageal cancer patients receiving one-lung ventilation under a lower FiO2

Arterial oxygenation is often impaired during one-lung ventilation (OLV), due to both pulmonary shunt and atelectasis. Lower fraction of inspiration O2 (FiO2) may reduce inflammation and complications, but may increase the risk of hypoxemia. The aim of this randomized controlled parallel trial was to analyze whether higher positive end-expiratory pressure (PEEP) could improve oxygenation and maintain lower levels of inflammation during OLV under a lower FiO2. One hundred and twenty patients with selective thoracotomy for esophageal cancer (EC) were classified randomly into four groups on a ratio of 1:1:1:1 using a computer-generated list, including Group A (FiO2 =0.6, PEEP =0), Group B (FiO2 =0.6, PEEP =5 cmH2O), Group C (FiO2 =1.0, PEEP =8 cmH2O), and Group D (FiO2 =1.0, PEEP =10 cmH2O). The oxygenation and pulmonary shunt were primary outcomes. Haemodynamics, respiratory mechanics, serum IL-6 and IL-10 levels, and complications were taken as secondary outcomes. Follow-up was terminated until discharge. Two patients in Group A and two in Group D were excluded due to hypoxemia and hypotension, respectively. Then the data of 116 patients (Group A =28, Group B =30 Group C =30, and Group D =28) were assessed for final analysis. Compared with Group B, the partial pressure of oxygen (PaO2) and dynamic compliance during OLV in Group D were significantly increased from 15 minutes to 60 minutes, while pulmonary shunt was significantly decreased (P>0.05). Patients in Group D had higher levels of central venous pressure (CVP) and airway pressure (Paw) during OLV and higher levels of IL-6 and IL-10 after OLV compared with Group B (P>0.05). No statistical differences were found in oxygen saturation (SaO2), PvO2 (partial pressure of oxygen in venous blood), partial pressure of end-tidal carbon dioxide (ETCO2), partial pressure of carbon dioxide in artery (PaCO2), heart rate (HR), mean arterial pressure (MAP), and complications among the four groups (P>0.05). Higher PEEP increased the oxygenation under 60% O2 during OLV. However, the haemodynamics and respiratory mechanics changed, and the levels of inflammation increased. A higher PEEP under 60% O2 during OLV is not recommended. Chinese Clinical Trial Registry ChiCTR1900024726.

Ventilação estratégica reduz lesão pulmonar contralateral não ventilada induzido pela ventilação pulmonar unilateral em coelhos

ABSTRACT One lung ventilation (OLV) often results in trauma to the unventilated contralateral lung. This study aims to evaluate the effects of different OLV regimens on the injury of the unventilated contralateral lung to identify the best conditions for OLV. Forty rabbits were divided into five groups: a sham group, OLV group I (fraction of inspired oxygen (FIO2) 1.0, tidal volume (VT) 8mL/kg, respiratory rate (R) 40 breaths/min and inspiratory/expiratory ratio (I:E) 1:2), OLV group II (FIO2=1.0, VT 8mL/kg, R 40 breaths/min, I:E 1:2, and positive end-expiratory pressure (PEEP) 5 cm H2O), OLV group III (FIO2 1.0, VT 6mL/kg, R 40 breaths/min, I:E 1:2 and PEEP 5 cm H2O) and OLV group IV (FIO2 0.8, VT 6mL/kg, R 40 breaths/min, I:E 1:2 and PEEP 5 cm H2O). Animals from all OLV groups received two-lung ventilation (TLV) to establish a baseline, followed by one of the indicated OLV regimens. The rabbits in the sham group were intubated through trachea and ventilated with fresh air. Arterial blood gas samples were collected, lung injury parameters were evaluated, and the concentrations of TNF-α and IL-8 in bronchoalveolar lavage fluid (BALF) and pulmonary surfactant protein A (SPA) in the unventilated lung were also measured. In OLV group I, the unventilated left lung had higher TNF-α, IL-8 and lung injury score but lower SPA than the ventilated right lung. In OLV groups I to III, the concentrations of TNF-α, IL-8 and lung injury score in the left lung decreased but SPA increased. No differences in these parameters between OLV groups III and IV were observed. Strategic ventilation designed for OLV groups III and IV reduced OLV-induced injury of the non-ventilated contralateral lung in rabbits.

Procedural times in early non-intubated VATS program - a propensity score analysis

BackgroundNon-intubated video-assisted thoracic surgery (NiVATS) has been introduced to surgical medicine in order to reduce the invasiveness of anesthetic procedures and avoid adverse effects of intubation and one-lung ventilation (OLV). The aim of this study is to determine the time effectiveness of a NiVATS program compared to conventional OLV.MethodsThis retrospective analysis included all patients in Leipzig University Hospital that needed minor VATS surgery between November 2016 and October 2019 constituting a NiVATS (n = 67) and an OLV (n = 36) group. Perioperative data was matched via propensity score analysis, identifying two comparable groups with 23 patients. Matched pairs were compared via t-Test.ResultsPatients in NiVATS and OLV group show no significant differences other than the type of surgical procedure performed. Wedge resection was performed significantly more often under NiVATS conditions than with OLV (p = 0,043). Recovery time was significantly reduced by 7 min (p = 0,000) in the NiVATS group. There was no significant difference in the time for induction of anesthesia, duration of surgical procedure or overall procedural time.ConclusionsRecovery time was significantly shorter in NiVATS, but this effect disappeared when extrapolated to total procedural time. Even during the implementation phase of NiVATS programs, no extension of procedural times occurs.

Dexmedetomidine alleviates non-ventilation associated lung injury via modulating immunology phenotypes of macrophages

AimsWe aimed to evaluate the effect of Dexmedetomidine (Dex) on immunology function of macrophages and inflammatory reactions in non-ventilated lung tissues from both humans and rats. Main methodsPatients scheduled for lung lobectomy were randomly assigned to traditional anesthesia group or Dex anesthesia group, 15 subjects in each group. CD68, CD86 and CD206 were used to mark activate and polarized macrophages using immunofluorescence staining in human lung tissues. Sprague-Dawley rats were used to set lung injury model and randomly divided into Control group, one-lung ventilation group (CLI group) and CLI + Dex group. Lung tissues and bronchoalveolar lavage fluid (BALF) from non-ventilated lungs were collected. The acquired lung tissues were subjected to hematoxylin-eosin (H&E) staining and the inflammatory cells in BALF were calculated. Levels of cytokines and chemokines were detected by enzyme-linked immunosorbent assays (ELISA). Key findingsResults from humans showed that anesthesia with Dex decreased the number of both CD68 positive cells and CD86 positive cells and down-regulated level of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and monocyte chemotactic protein 1 (MCP-1) in human lung. Results from rats demonstrated that treatment with Dex reversed the increased inflammatory cells in lung and the increased levels of TNF-α, interleukin-1β (IL-β), MCP-1 and chemokine (C-X-C motif) ligand 1 (CXCL1) resulted from non-ventilation; Dex increased the anti-inflammatory cytokine interleukin-10 (IL-10) in BALF from non-ventilated lung. SignificanceThis study showed that Dex modulated the activation and immunological function of macrophages in non-ventilated lung and revealed a protective role in collapsed lung injury.

Extraluminal Placement of the Bronchial Blocker in Infants Undergoing Thoracoscopic Surgery: A Randomized Controlled Study

The purpose of the present study was to evaluate the efficacy of extraluminal use of the bronchial blocker (BB) for one-lung ventilation (OLV) in infants undergoing thoracoscopic surgery. This was a prospective, randomized, controlled clinical study. University hospital. The study comprised 60 infants undergoing thoracoscopic surgery. The study included 2 groups. A BB was placed extraluminally for OLV in group A, and a single-lumen endobronchial tube was inserted into the desired mainstem bronchus for OLV in group C. The placement time (4.0 ± 0.6 min v 6.3 ± 4.1 min; p = 0.04) and the number of repositions (2 v 11; p = 0.005) were less in group A. There were significant differences in the heart rate and blood pressure after insertion between the 2 groups (p < 0.05). The tidal volumes and end-tidal pressure of carbon dioxide values 10 minutes after the initiation of OLV were similar between the 2 groups (p > 0.05). The incidence of intraoperative hypoxemia was reduced in group A compared with group C (0% v 20%; p = 0.024). No postoperative adverse events were observed in either group. Extraluminal use of the BB may provide a solution for a rapid placement and excellent quality of lung isolation, and it may reduce the incidence of intraoperative hypoxemia in infants without increasing the incidence of hoarseness.

Efficacy of artificial pneumothorax under two-lung ventilation in video-assisted thoracoscopic surgery for esophageal cancer.

One-lung ventilation (OLV) is the standard and widely applied ventilation approach used in video-assisted thoracoscopic surgery for esophageal cancer (VATS-e). To address the disadvantages of OLV with respect to difficulties in intubation and induction, as well as the risk of respiratory complications, two-lung ventilation (TLV) with artificial pneumothorax has been introduced for use in VATS-e. However, no studies have yet compared TLV and OLV with postoperative infection and inflammation in the prone position over time postoperatively. Here, we investigated the efficacy of TLV in patients undergoing VATS-e in the prone position. Between April 2010 and December 2016, 119 patients underwent VATS-e under OLV or TLV with carbon dioxide insufflation. Clinical characteristics, surgical outcomes, and postoperative outcomes, including oxygenation and systemic inflammatory responses, were compared between patients who underwent OLV and those who underwent TLV. Clinical characteristics other than pT stage were comparable between groups. The TLV group had shorter thoracic operation time than the OLV group. No patients underwent conversion to open thoracotomy. The PaO2/FiO2 ratios of the TLV group on postoperative day (POD) 5 and on POD7 were significantly higher than those of the OLV group. C-reactive protein levels on POD7 were lower in the TLV group than in the OLV group. There were no significant differences with respect to postoperative complications between the OLV and TLV groups. In the TLV group, the white blood cell count on POD7 was significantly lower than that in the OLV group; body temperature showed a similar trend immediately after surgery and on POD1. In this study, we demonstrated that, compared with OLV, TLV in the prone position provides better oxygenation and reduced inflammation in the postoperative course. Accordingly, TLV might be more useful than OLV for ventilation during esophageal cancer surgery.

Effect of inhaled aerosolized budesonide and salbutamol on HIF-1α/VEGF signaling pathway in collapsed lung tissues of rabbits undergoing one-lung ventilation

Objective To evaluate the effect of inhaled aerosolized budesonide and salbutamol on hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) signaling pathway in collapsed lung tissues of rabbits undergoing one-lung ventilation (OLV). Methods Twenty-four healthy male New Zealand white rabbits, aged 5-6 months, weighing 2.5-3.0 kg, were randomized into 3 groups (n=8 each) using a random number table method: two-lung ventilation (TLV) group, OLV group, and budesonide and salbutamol aerosol inhalation group (group B+ S). Bilateral lungs were ventilated for 3 h in group TLV, and the left lung was ventilated for 2 h followed by 1-h TLV in group OLV and B+ S group.In group B+ S, aerosolized salbutamol 0.15 mg/kg and budesonide 1 mg in normal saline (2 ml in total) was inhaled before OLV.The equal volume of normal saline was given instead in TLV and OLV groups.Volume-controlled ventilation was used in each group.Before beginning of aerosol inhalation (T0), immediately after the end of aerosol inhalation (T1), and at 1, 2 and 3 h of ventilation (T2-4), arterial blood samples were obtained for blood gas analysis.Oxygenation index was calculated.The rabbits were sacrificed at the end of ventilation, and lower lobe tissues were obtained from the collapsed lung for examination of the pathological changes (with a light microscope) which were scored and for determination of HIF-1α and VEGF expression in lung tissues (by Western blot). Results Compared with group TLV, oxygenation index was significantly decreased at T2-4, the concentration of lactic acid and lung injury score were increased, and the expression of HIF-1α and VEGF was up-regulated in group OLV and group B+ S (P<0.05). Compared with group OLV, oxygenation index was significantly increased at T2-4, the concentration of lactic acid and lung injury score were decreased, and the expression of HIF-1α and VEGF was down-regulated in group S+ B (P<0.05). Conclusion The mechanism by which inhaled aerosolized budesonide and salbutamol reduces OLV-induced injury to the collapsed lung is related to blocking HIF-1α/VEGF signaling pathway in lung tissues of rabbits. Key words: One-lung ventilation; Acute lung injury; Budesonide; Albuterol; Bronchodilator agents; Administration, inhalation

Video-assisted thoracoscopic total thymectomy: two-lung ventilation with artificial pneumothorax

Objectives: Double-lumen endotracheal tube (DLET) and one-lung ventilation (OLV) have been generally accepted as the classic anesthetic method in video-assisted thoracoscopic total thymectomy (VATT). However, there are still some disadvantages of DLET. Two-lung ventilation (TLV) with single-lumen endotracheal tube (SLET) is considered to be an alternative in VATT to avoid these disadvantages. This study evaluated the safety and feasibility of TLV in VATT by comparing it with OLV cases.Material and methods: We retrospectively screened 198 patients who received TLV unilateral thoracic incision VATT and 117 patients who received OLV unilateral thoracic incision VATT. Perioperative data were analyzed, including surgical variables, intraoperative hemodynamic parameters, and postoperative complications and hospital stay.Results: No significant differences with regard to operative time (p = .146), postoperative hospital stay (p = .553), complications (p = .254), hemodynamic parameters and pulse oxygen saturation (SpO2) were found between TLV group and OLV group. However, end-tidal CO2 (EtCO2) was higher in TLV group at 15 min (39.95 ± 5.03 vs 38.70 ± 4.57, p = .021) and 30 min (41.91 ± 5.50 vs 38.91 ± 4.51, p < .001) after initiation of the operation.Conclusions: It is safe and feasible to adopt TLV using SLET with CO2 insufflation artificial pneumothorax in unilateral thoracic incision VATT.

Protective effects of endothelin-1 recepter antagonist against lung injury during one-lung ventilation in rabbits

Objective To investigate the protective effect of endothelin-1 (ET-1) recepter antagonist against lung injury during one-lung ventilation (OLV) in rabbits. Methods Fifteen big-ear Japanese rabbits (no limit of male or female) were divided into 3 groups randomly (n=5 in each group): sham group (group T), one-lung ventilation group (group O), OLV+ BQ-123 group (group OB). Two lungs were ventilated for 2.5 h in group T, and one lung was ventilated for 2.0 h followed by 0.5 h OLV in group O and group OB. About 10 min before one lung ventilation, BQ-123 (50 μg/kg) was injected through the femoral vein in group OB. Group O and group OB received the same amount of normal saline at the same time point. During the experiment, arterial blood gas analyses were done at the time of before OLV (T0), 1 h after OLV (T1), 2 h after OLV (T2) and 0.5 h after TLV (T3), as well as OI was calculated. At end of the experiment, the two lungs were removed for light microscopic evaluations, and the content of ET-1, activity of superoxide dismutase (SOD), concentrations of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined in lung tissures. Results As compared with group T, the content of ET-1 [(165.73±23.87) ng/L vs. (94.31±9.86) ng/L], the activity of SOD [(62.21±2.10) U/mg vs. (84.42±6.77) U/mg], the concentration of IL-6 [(20.82±1.33) ng/L vs. (7.97±1.98) ng/L] and TNF-α [(37.11±5.03) ng/L vs. (19.47±4.30) ng/L](P<0.05) in lung tissue of group O were increased, the pathological score was increased, and the OI was decreased at 2.0 hafter one-lung ventilation. As compared with group O, the content of ET-1 [(119.37±8.55) ng/L vs. (165.73±23.87) ng/L], the activity of SOD [(78.29±1.78) U/mg vs. (62.21±2.10) U/mg] and the concentrations of IL-6 [(14.13±1.26) ng/L vs. (20.82±1.33) ng/L] and TNF-α [(26.30±2.18) ng/L vs. (37.11±5.03) ng/L] in the collapsed lung tissue of group OB were decreased (P<0.05), and the pathological score decreased. In group O and OB, the content of ET-1 and concentrations of IL-6 and TNF-α in the collapsed lung were significantly higher than those in the ventilated lung, the activity of SOD was decreased and the pathological score was increased (P<0.05). Conclusion ET-1 receptor antagonist has protective effect on lung injury during one-lung ventilation in rabbits, which may be related to the reduction of ET-1 binding to receptor and the inhibition of inflammatory response and oxidative stress reaction in lung tissue. Key words: Lung injury; One-lung ventilation; Endothelin-1 recepter antagonist; Rabbit

Preemptive one lung ventilation enhances lung collapse during thoracoscopic surgery: A randomized controlled trial

In routine practice, one lung ventilation (OLV) is initiated upon pleural opening. We conducted a randomized controlled trial to compare lung collapse after preemptive OLV versus conventional OLV in thoracoscopic surgery. A total of 67 patients were enrolled (34 with conventional OLV; 33 with preemptive OLV). Preemptive OLV was conducted by closing the DLT lumen to the non‐ventilated lung immediately upon assuming the lateral position with the distal port closed to the atmosphere until pleural opening (>6 minutes in all cases). Lung collapse was assessed at 1, 5, 10, 20, 30 and 40 minutes after pleural opening using a 10‐point rating scale (10: complete collapse). The primary end point was the duration from pleural opening to satisfactory lung collapse (score of 8). Secondary end points included PaO2 and hypoxemia. The duration from pleural opening to satisfactory lung collapse was shorter in the preemptive OLV group (9.1 ± 1.2 vs. 14.1 ± 4.7 minutes, P < 0.01). PaO2 was comparable between the two groups prior to anesthetic induction (T0), and 20 (T2), 40 minutes (T3) after pleural incision, but was lower in the preemptive OLV group at zero minutes after pleural incision (T1) (457.5 ± 19.0 vs. 483.1 ± 18.1 mmHg, P < 0.01). No patients in either group developed hypoxemia. In summary, preemptive OLV expedites lung collapse during thoracoscopic surgery with minimal safety concern.

The roles of NF-kB in the development of lung injury after one-lung ventilation.

To explore the roles of NF-kB in the development of lung injury after one-lung ventilation. Eighteen Sprague-Dawley (SD) rats were randomly divided into 3 groups including control group, one-lung ventilation (OL) group and NF-kB inhibitor pyrrolidine dithiocarbamate (PDTC) group, with 6 rats in each group. Rats in OL and PDTC groups were used to establish one-lung ventilation model, and rats in PDTC group were subjected to intravenous injection of NF-kB specific inhibitor PDTC at 30 min before model construction. One-lung ventilation was performed for 3 h, and arterial blood gas analyzer was used for blood gas analysis. The hemodynamics and respiratory mechanics parameters were detected. The respiratory index (RI) and oxygenation index (OI) were calculated. The pathological changes of lung tissue were observed by HE staining. The levels of TNF-α, IL-1β, IL-6, and IL-8 in lung tissue were detected by ELISA. The expression levels of p65, p-p65, p-IκBα and IκBα and the activity of NF-Kβ in lung tissue were detected by Western Blot. Compared with OL group, HR, RI and W/D were significantly reduced and MAP and OI were significantly increased in PDTC group (p<0.05). Compared with OL group, alveolar fluid exudation, pulmonary interstitial thickening and inflammatory cell infiltration were significantly improved in PDTC group. The levels of TNF-α, IL-1β, IL-6 and IL-8 in PDTC group were significantly lower than in OL group (p<0.05). The ratios of p-p65/p65 and p-IκBα/IκBα and the activity of NF-kB in OL group were significantly reduced than in PDTC group (p<0.05). NF-kB can promote lung injury after one-lung ventilation, and the inhibition of NF-kB may be a new way for the treatment of this disease.

Sevoflurane attenuates ventilator‑induced lung injury by regulating c‑PLA2 expression.

The aim of the present study was to investigate the potential role of club cell secretory protein (CCSP), an endogenous modulator, in reducing pulmonary inflammation induced by sevoflurane following one‑lung ventilation (OLV). Healthy Japanese white rabbits were randomly assigned to six groups: Sham‑operated group (group S); respiratory management of OLV group (group O); OLV+sevoflurane treated group (group OF), club cells exfoliated+sham‑operated group (group NA), club cells exfoliated+OLV group (group NAO); and club cells exfoliated+OLV+sevoflurane treated group (group NAOF). At the end of the experimental observation, all animals in the different groups were sacrificed and lung injury was evaluated according to the lung wet/dry weight ratio and histological scoring system. Lung homogenates were harvested to detect the mRNA and protein expression of cytosolic phospholipase A2 (c‑PLA2) and CCSP. The content of arachidonic acid was measured using an ELISA. Following OLV treatment, c‑PLA2 expression was increased, CCSP expression was decreased and lung injury scores were significantly increased. Sevoflurane inhalation in the OLV‑treated group induced an upregulation of CCSP and a downregulation of c‑PLA2 expression. In the group NAO, in which the club cells were simultaneously exfoliated, OLV caused more severe lung damage and induced higher expression of c‑PLA2 compared with that in group O. However, sevoflurane inhalation reduced the extent of lung injury and the expression of c‑PLA2, even when the endogenous modulator of lung inflammation, CCSP, was exfoliated (group NAOF). These results indicated that OLV promoted lung inflammation through the CCSP and c‑PLA2 pathway. However, the results from the club cells exfoliated group indicated that the CCSP may not be involved in the protective effect exerted by sevoflurane inhalation.

Effect of One-Lung Ventilation on Blood Sevoflurane and Desflurane Concentrations

To determine the blood sevoflurane and desflurane concentrations during one-lung ventilation (OLV). Randomized, single-blind study. Single university hospital. The study comprised 24 patients, 35 to 70years old who were scheduled for either a major abdominal surgery or thoracotomy. The patients were divided into the following 4 groups: sevoflurane two-lung ventilation (TLV), sevoflurane OLV, desflurane TLV, and desflurane OLV. Vaporizers were set at 1.5% sevoflurane or 6% desflurane. In the TLV groups, blood samples were taken in 10-minute intervals starting 40 minutes after the start of TLV (T1-T9) for blood gas analysis and gas chromatography. In the OLV groups, the first sample was collected at 40 minutes of TLV (T1), and other samples were collected in 10-minute intervals from the start of OLV (T2-T9). Saturation of peripheral oxygen (SpO2), hemodynamic variables, and inspired and end-tidal volatiles were recorded. The fraction uptake of the volatile agents (F) was calculated for each patient at the same time points. The mean arterial sevoflurane concentration in the sevoflurane OLV group at T1 decreased from 40.7 ± 4.4 to 30.2 ± 2.5 µg/mL at T3 (p = 0.014, 26% decrease). In the OLV desflurane group, the mean arterial desflurane concentration at T1 declined from 224.6 ± 44.8 to 159.8 ± 32 µg/mL at T3 (p=0.018, 29% decrease). However, the reduction of sevoflurane concentration compared with that of desflurane at T3 was not statistically significant (p = 0.31). In addition, the fraction uptake of the volatile agents values significantly increased at the start of OLV (p = 0.001). An OLV procedure causes a decrease in the both arterial and venous blood concentrations of sevoflurane and desflurane. This reduction is believed to be due to ventilation-perfusion mismatch.

The impact of spontaneous ventilation on non-operative lung injury in thoracic surgery: a randomized controlled rabbit model study.

One-lung ventilation (OLV) with general anaesthesia may increase adverse effects after thoracic surgery, specifically ventilator-induced lung injury. Spontaneous ventilation (SV) has no mechanical ventilation process, thus, we established a rabbit model to assess non-operative lung injury between OLV and SV. Thirty-six rabbits were randomly divided into 6 groups: OLV and SV (0, 2 and 4 h). Blood gas analysis was performed after thoracic surgery. Lung tissue and bronchoalveolar lavage fluid were obtained from the non-operative lung. Pathological injury score in lung tissue and tumour necrosis factor α (TNF-α) level in bronchoalveolar lavage fluid using enzyme-linked immunosorbent assay were determined. Moreover, messenger RNA and protein of TNF-α in lung tissue were also determined by quantitative reverse transcriptase polymerase chain reaction and immunohistochemistry. Compared with the OLV group, significantly higher partial pressure of carbon dioxide (47.78 ± 3.57 vs 38.95 ± 3.88 mmHg, P < 0.01) and partial pressure of oxygen (101.08 ± 13.1 vs 85.6 ± 11.07 mmHg, P < 0.01), as well as a significantly lower pathological injury score (6.83 ± 1.17 vs 8.83 ± 1.72, P < 0.05), TNF-α level in bronchoalveolar lavage fluid (290.32 ± 29.38 vs 368.43 ± 31.26 pg/ml, P < 0.01), TNF-α messenger RNA (6.31 ± 1.13 vs 8.6 ± 1.34, P < 0.01), immunostaining intensity in lung tissue were found at 4 h in the SV group. However, there are no significant differences between OLV and SV groups at 2 h (P > 0.05), except in TNF-α messenger RNA. Based on this rabbit model, SV for thoracic surgery is not inferior to OLV in terms of lung injury. Considering our results, when performing time-consuming thoracic procedures under OLV, surgeons should more closely examine patients for non-operative lung injury postoperatively.

Efficacy of high frequency two-lung ventilation with low tidal volume assisted by CO2 pneumothorax for airway management in patients undergoing thoracoscopic radical resection of esophagus cancer

Objective To evaluate the efficacy of high frequency two-lung ventilation(TLV)with low tidal volume assisted by CO2 pneumothorax for airway management in patients undergoing thoracoscopic radical resection of esophagus cancer. Methods Thirty patients of both sexes, aged 48-64 yr, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, scheduled for elective thoracoscopic radical resection of esophagus cancer, were divided into 2 groups(n =15 each)using a random number table: one-lung ventilation group(group O)and TLV group(group T). A left-sided double-lumen tube was inserted orally in group O, and a single-lumen tube was placed orally in group T. During thoracoscopic surgery, the left lung was ventilated, with tidal volume 8 ml/kg and respiratory rate 14 breaths/min in group O. In group T, artificial pneumothorax was induced by continuous CO2 insufflation with CO2 pressure at 10 mmHg, and bilateral lungs were ventilated, with tidal volume 5 ml/kg and respiratory rate 20 breaths/min.Mean arterial pressure and heart rate were recorded before induction of anesthesia, immediately after intubation(T1), at 10 min after intubation(T2), at 30 min after the start of thoracoscopic surgery(T3), immediately after the end of thoracoscopic surgery(T4)and at 30 min of TLV(T5). Arterial blood samples were collected for blood gas analysis at T2, T3, T4 and T5.The exposure of the surgical field and the number of lymph node dissection in the left recurrent laryngeal nerve chain were recorded during surgery.The emergence time, extubation time and time for recovery of consciousness were recorded. Results Arterial oxygen partial pressure was significantly lower at T3, 4 than at T2 in the two groups, and arterial carbon dioxide partial pressure was significantly higher, and the pH value was lower at T3, 4 than at T2 in group T(P 0.05). Conclusion High frequency TLV with low tidal volume when assisted by CO2 pneumothorax can serve as a feasible mode for airway management in patients undergoing thoracoscopic radical resection of esophagus cancer. Key words: Tidal volume; Respiration, artificial; Carbon dioxide; Thoracoscope; Esophageal neoplasms; Fast frequency

Changes in status of macrophages during non-ventilated lung injury in patients undergoing long-time one-lung ventilation

Objective To evaluate the changes in the status of macrophages during the non-ventilated lung injury in the patients undergoing long-time one-lung ventilation(OLV). Methods Thirty patients of both sexes, aged 35-64 yr, weighing 50-80 kg, of American Society of Anesthesiologists physical status Ⅰor Ⅱ, scheduled for elective pulmonary lobectomy for lung cancer, were divided into 2 groups(n=15 each)according to the time of OLV: short-time OLV group( 2 h, group L). Anesthesia was routinely induced and maintained.Normal lung tissues around the cancer tissues from the lobe of the lung excised were obtained for microscopic examination of pathologic changes which were scored.The activated macrophages(CD68 positive), polarized M1 macrophages(CD86 positive)and polarized M2 macrophages(CD206 positive)in lung tissues were detected using immunofluorescence.The ratio of CD86 positive cells to CD206 positive cells was calculated. Results Compared with group S, lung injury scores on the non-ventilated side were significantly increased, the number of CD68, CD86 and CD206 positive cells in lung tissues was increased, and the ratio of CD86 positive cells to CD206 positive cells was increased in group L(P<0.05). Conclusion Long-time OLV(>2 h)can result in increased number of activated macrophages, especially the polarized M1 macrophages, which may be one of the mechanisms underlying lung injury on the non-ventilated side. Key words: Respiration, artificial; Respiratory distress syndrome, adult; Macrophages, alveolar

Gamma Coherences in the Default Mode Resting State as a Measure of Consciousness Level

Abstract Recent findings indicate that the default mode resting state network (DMRSN) is closely associated with conscious awareness. Thus changes in consciousness level could be reflected in turn in the DMRSN functional state. One of the most important requirements for proper network function is connectivity within the network structural constituents. One of the measures of functional connectivity is analysis of the EEG coherences. In this study we have examined changes in the mean coherences in the gamma spectral band 30–45 Hz in the DMRSN during general anaesthesia (GA) in the open thorax surgery were investigated in twenty patients. They were compared with physiologic EEG findings in twenty alert subjects and the mathematical model of brain death. Results of this study indicate that the decrease in coherences in the physiologic EEG and the patients with one lung ventilation (OLV) groups was roughly proportional to the increasing distance between the electrodes. This created some kind of a structure in the DMRSN. In the OLV group the main finding was a decrease in the coherences in the gamma band. Ten of the anaesthetized subjects showed a clear burst suppression pattern. During this condition the coherences in the pairs connecting the posterior parts of the network decreased. Moreover, the differences between the connections of the anterior to posterior parts of the DMRSN and connections between the posterior parts of the DMRSN were almost lost. However, they showed still highly significant differences in all items when compared with the mathematical model of brain death. In summary the results suggest that the functional connectivity in the DMRSN assessed by mean coherences could be a reliable method for assessing the depth of GA and may be useful for understanding disorders of consciousness in general.

Effect of curcumin pretreatment on JNK signaling pathway during one-lung ventilation-induced acute lung injury in mice

Objective To evaluate the effect of curcumin pretreatment on c-Jun N-terminal kinase(JNK)signaling pathway during one-lung ventilation(OLV)-induced acute lung injury in mice. Methods Ninety SPF male C57BL/6J mice, aged 6-9 weeks, weighing 18-24 g, were randomly divided into 6 groups(n=15 each)using a random number table: two-lung ventilation(TLV)group; OLV group; curcumin 100, 150, 200 and 250 mg/kg groups(C100, C150, C200 and C250 groups). The corresponding doses of curcumin were administered intraperitoneally at 2 h before one-lung ventilation in C100, C150, C200 and C250 groups.The animals were tracheally intubated and mechanically ventilated in volume-controlled mode.The ventilator settings were adjusted to maintain the end-tidal pressure of carbon dioxide at 35-45 mmHg.In OLV, C100, C150, C200 and C250 groups, unilateral lung was ventilated for 1.5 h followed by 0.5 h of TLV.Bilateral lungs were ventilated for 2.0 h in group TLV.Peak airway pressure and airway pressure were recorded at 1.5 h of OLV and 0.5 h of TLV.At the end of mechanical ventilation, left lungs were removed for microscopic examination of the pathologic changes, and the index of quantitative assessment for alveolar damage(IQA)was recorded.Wet/dry lung weight ratio(W/D ratio)was determined, and the cell apoptosis in lung tissues was detected using TUNEL.The apoptosis index(AI)was calculated.The expression of JNK mRNA was determined using real-time polymerase chain reaction.The expression of JNK and phosphorylated JNK was determined by Western blot.The phosphorylation of JNK was calculated. Results Compared with group TLV, the IQA, W/D ratio, AI, expression of JNK mRNA and phosphorylation of JNK were significantly increased in group OLV(P 0.05). Compared with group OLV, the pathological changes were significantly attenuated in sequence in C150, C200 and C250 groups. Conclusion The mechanism by which curcumin pretreatment reduces cell apoptosis during OLV-induced acute lung injury is related to inhibition of JNK signaling pathway activation in mice. Key words: Curcumin; JNK mitogen-activated protein kinases; Apoptosis; Respiratory distress syndrome, adult; Respiration, artificial