ObjectiveTo investigate the current status of routine practice and perspective of anesthesiologists regarding ventilation strategies during cardiac surgery, and to analyze whether there is a gap between the clinical application and theoretical understanding of lung-protective ventilation (LPV) strategies. MethodsWe conducted a multi-institutional cross-sectional survey of anesthesiologists working at high-volume (>1000 cardiac procedures each year) Chinese hospitals. The electronic questionnaire was designed and distributed from September 2021 to February 2022. ResultsA total of 323 replies were collected and 297 (92.0%) replies were valid. Among the respondents, 84.8% (252/297) performed the combination of low tidal volume (VT), positive end-expiratory pressure (PEEP) and alveolar recruitment maneuver (ARM) during non-CPB period. The vast majority of respondents (90.6%, 269/297) ventilated patients with the VT of 6-8 mL/kg. 92.3% (274/297) of respondents applied PEEP, among those 57.9% (172/297) set a PEEP level <5 cm H2O. Most of the respondents (67.3%, 200/297) performed intraoperative ARM, and manual ARM was used by 86.2% (256/297) of anesthesiologists. During CPB, 89.9% (267/297) of respondents withdrew mechanical ventilation, and 29.6% (88/297) performed ARM. ConclusionThis national survey in China showed that the majority of anesthesiologists adopted LPV strategy with the combination of low VT, PEEP and ARM during cardiac surgery. Except VT, the intraoperative ventilator settings varied widely from one anesthesiologist to another. Meanwhile, there is a gap between the clinical practice and theoretical understanding of LPV.
Objective To study the efficacy of invasive ventilation in critical severe acute respiratory syndrome (SARS). Methods Retrospective analysis was applied to study the efficacy of invasive ventilation and the effect of isolating and protecting measures in 6 critical SARS patients and the effect of isolation measures in ICU from November 2002 to April 2003. Results Six SARS patients were successfully weaned from mechanical ventilation and left hospital. Hypoxemia and oxygenation index（PaO2/FiO2）improved significantly after ventilation (Plt;0.01), peak inspiratory airway pressure (P=0.002), mean airway pressure (P=0.004), and the level of positive expiration end pressure decreased significantly (Plt;0.001). Ventilator-associated pneumonia occurred in 5 patients. Sedatives were used less and the duration of ventilation was shorter when using PRVC compared with SIMV. There was no SARS nosocomial infection among medical staff, other patients and their families. Conclusions Application of invasive ventilation and effective isolation measures could reduce the death rate, shorten the duration of ventilation, and also decrease SARS nosocomial infection.
ObjectiveTo explore the effects of different concentrations of sevoflurane on hyperoxia-induced lung injury in rat.MethodsThe 72 SD rats were randomly divided into control group C (n=12); sevoflurane inhalation group S, group S contains 5 subgroups (n=12) S0, S1.0, S1.5, S2.0, S2.5. Group C wasn’t given any treatment, rats in group S were inhaled 95% oxygen for 48 hours to establish a hyperoxia-induced lung injury model. then rats in each subgroup inhaled sevoflurane at different concentrations of 0%, 1.0%, 1.5%, 2.0% and 2.5% for 1 h respectively, rats in group C were breathe air freely. At the two time points which include inhaled 95% oxygen for 48 hours, and sevoflurane was inhaled for 1 h, blood was collected by the abdominal aorta, then arterial blood was used for blood gas analysis; using enzyme linked immunosorbent assay for the detection of serum tumor necrosis factor (TNF) -α and interleukin (IL) -8 and IL-6 concentration; HE staining was carried out in the right lung, and the pathological changes of lung tissue were observed under light microscope; Wet to dry ratio (W/D) of the left lung was taken.ResultsAfter inhalation of 95% oxygen for 48 hours (T1): compared with the group C, group S of arterial blood gas results suggested that the PaO2 value decreased, PaCO2 value increased. The degree of lung tissue injury and the pathological score, TNF-α, IL-8 and IL-6, W/D content increased significantly (P < 0.05), there was no significant difference between the S0 to S2.5 groups; After treatment with sevoflurane for 1 h (T2): compared with the group C, group S of arterial blood gas results suggested that the PaO2 value decreased, PaCO2 value increased. the degree of lung tissue injury and the pathological score, TNF-α, IL-8 and IL-6, W/D content increased significantly (P < 0.05); Compared with before sevoflurane treatment, the PaO2 value increased, PaCO2 value decreased, TNF-α, IL-8 and IL-6, W/D content decreased, pathological score decreased in group S1.0 to S2.5 (P <0.05), but there was no significant difference in group S0; After treatment with sevoflurane, compared with S2.0 group, the PaO2 value decreased, PaCO2 value increased, TNF-, IL-8 and IL-6, W/D content increased, pathological score increased in the group S1.0 and S1.5 (P < 0.05), but there was no significant difference in group S2.5.ConclusionSevoflurane can effectively reduce the degree of lung injury caused by hyperoxia in rats especially when the concentration is 2%.
目的 探讨体外循环（CPB）期间行肺动脉灌注液对术后肺功能的保护作用。 方法 2007年1月－2011年4月30例在CPB下行单纯二尖瓣人工机械瓣置换术患者，随机分成肺保护组和对照组各15例，肺保护组患者CPB期间经肺动脉灌注低温肺保护液，对照组患者CPB期间未经肺动脉灌注低温肺保护液。监测两组患者在麻醉诱导后、阻断主动脉l0 min及开放主动脉l0 min，2 、12、24 h各时间点的呼吸指数（RI）、氧合指数（OI）、白介素6（IL-6）、肿瘤坏死因子α（TNF-α）及术前、术后肺动脉压力（PAPm）、静态肺顺应性（CLS）、气道阻力（AR）变化，并比较术后ICU监护时间、术后呼吸机辅助时间、住院天数及有无术后并发症等。 结果 两组IL-6、TNF-α、RI、OI、PAPm、AR、CLS比较差异均有统计学意义（P＜0.05）。但术后ICU监护时间及住院时间比较差异均无统计学意义（P＞0.05）。 结论 CPB期间行肺动脉灌注对术后肺功能具有保护作用。
Abstract： Ischemia postconditioning is a new concept based on ischemic preconditioning. It has become a hot topic in protection of ischemic-reperfusion injury because of its effective protection, relative ease of application, and postconditioning. However, its precise mechanisms and most effective application methods are still unclear. This review covers recent progress in the understanding, developments (in remote postconditioning and pharmacological postconditioning), applications to the protection of heart, lung, liver, kidney, and brain, mechanisms and appropriate protocol of ischemic post-conditioning.
ObjectiveTo evaluate the effect of driving pressure-guided lung protective ventilation strategy on lung function in adult patients under elective cardiac surgery with cardiopulmonary bypass.MethodsIn this randomized controlled trial, 106 patients scheduled for elective valve surgery via median sternal incision under cardiopulmonary bypass from July to October 2020 at West China Hospital of Sichuan University were included in final analysis. Patients were divided into two groups randomly. Both groups received volume-controlled ventilation. A protective ventilation group (a control group, n=53) underwent traditional lung protective ventilation strategy with positive end-expiratory pressure (PEEP) of 5 cm H2O and received conventional protective ventilation with tidal volume of 7 mL/kg of predicted body weight and PEEP of 5 cm H2O, and recruitment maneuver. An individualized PEEP group (a driving pressure group, n=53) received the same tidal volume and recruitment, but with individualized PEEP which produced the lowest driving pressure. The primary outcome was oxygen index (OI) after ICU admission in 30 minutes, and the secondary outcomes were the incidence of OI below 300 mm Hg, the severity of OI descending scale (the Berlin definition), the incidence of pulmonary complications at 7 days after surgery and surgeons’ satisfaction on ventilation.ResultsThere was a statistical difference in OI after ICU admission in 30 minutes between the two groups (273.5±75.5 mm Hg vs. 358.0±65.3 mm Hg, P=0.00). The driving pressure group had lower incidence of postoperative OI<300 mm Hg (16.9% vs. 49.0%, OR=0.21, 95%CI 0.08-0.52, P=0.00) and less severity of OI classification than the control group (P=0.00). The incidence of pulmonary complications at 7 days after surgery was comparable between the driving pressure group and the control group (28.3% vs. 33.9%, OR=0.76, 95%CI 0.33-1.75, P=0.48). The atelectasis rate was lower in the driving pressure group (1.0% vs. 15.0%, OR=0.10, 95%CI 0.01-0.89, P=0.01).ConclusionApplication of driving pressure-guided ventilation is associated with a higher OI and less lung injury after ICU admission compared with the conventional protective ventilation in patients having valve surgery.
Objective To evaluate the efficacy of lung-protective strategies of ventilation (LPSV) in acute respiratory distress syndrome (ARDS) patients after thoracic operation. Methods-Thirtyseven ARDS patients without preoperative complications who had underwent thoracic surgery successfully were divided into the conventional mechanical ventilation group (CMV group, n=20) and lungprotective strategies of ventilation group (LPSV group，n=17). Results of arterial blood gas, index of oxygenation (PaO2/FiO2), airway plateau pressure (Pplat), inspiration peak pressure (PIP), PEEP, after ventilation treatment 24 h and mechanical ventilation time， pulmonary barotrauma and so on were observed. Results The mechanical ventilation time， pulmonary barotrauma and mortality of the LPSV group were 7.3d, 5.9％ and 29.4％ respectively, which were significantly better than those in the CMV group(17.6d，15.0％ and 60.0％, Plt;0.05). peak inflation pressure (PIP)，Pplat(plat pressure) in the LPSV group were significantly lower than those in the CMV group (Plt;0.05). However, there were no significant differences including arterial oxygen saturation (SaO2),pH, partial pressure of carbon dioxide in artery (PaCO2) and PaO2/FiO2 in two groups. Conclusion LPSV is more effective for the patients in the ARDS patients after thoracic operation compared to CMV, which can markedly reduce the ventilatorinduced lung injuryand (VILI) and mortality.