Real-time acquisition of pulmonary ventilation and perfusion information through thoracic electrical impedance tomography (EIT) holds significant clinical value. This study proposes a novel method based on the rime (RIME) algorithm-optimized variational mode decomposition (VMD) to separate lung ventilation and perfusion signals directly from raw voltage data prior to EIT image reconstruction, enabling independent imaging of both parameters. To validate this approach, EIT data were collected from 16 healthy volunteers under normal breathing and inspiratory breath-holding conditions. The RIME algorithm was employed to optimize VMD parameters by minimizing envelope entropy as the fitness function. The optimized VMD was then applied to separate raw data across all measurement channels in EIT, with spectral analysis identifying relevant components to reconstruct ventilation and perfusion signals. Results demonstrated that the structural similarity index (SSIM) between perfusion images derived from normal breathing and breath-holding states averaged approximately 84% across all 16 subjects, significantly outperforming traditional frequency-domain filtering methods in perfusion imaging accuracy. This method offers a promising technical advancement for real-time monitoring of pulmonary ventilation and perfusion, holding significant value for advancing the clinical application of EIT in the diagnosis and treatment of respiratory diseases.
Regional cerebral oxygen saturation cerebral oxygen saturation(rScO2) monitoring by using near-infrared spectroscopy(NIRS) is a simple, sensitive, continuous and noninvasive method, which can detect the change in oxygen supply and demand. It has already draw attentions and applications during perioperative in recent years. The technique was firstly used in cardiac surgery, thereafter some studies found thoracic surgery which mostly used one-lung ventilation also was necessary to monitor rScO2. A series of studies confirmed there were correlations among perioperative adverse events and rScO2. In this paper, we reviewed the basic principle of rScO2, summarized the applications of rScO2 in cardiac and thoracic surgery, discussed the existing problems.
ObjectiveTo evaluate the correlation between positive end-expiratory pressure (PEEP) level and postoperative pulmonary complications (PPCs) in patients undergoing thoracoscopic lung surgery. MethodsThe clinical data of patients who underwent elective thoracoscopic lung surgery at West China Hospital of Sichuan University from January 2022 to June 2023 were retrospectively analyzed. Patients were divided into 2 groups according to intraoperative PEEP levels: a PEEP 5 cm H2O group and a PEEP 10 cm H2O group. The incidence of PPCs in the two groups after matching was compared using a nearest neighbor matching method with a ratio of 1∶1, setting the clamp value as 0.02. ResultsA total of 538 patients were screened, and after propensity score-matching, a total of 229 pairs (458 patients) were matched, with an average age of 53.9 years and 69.4% (318/458) females. A total of 118 (25.8%) patients had PPCs during hospitalization after surgery, including 60 (26.2%) patients in the PEEP 5 cm H2O group and 58 (25.3%) patients in the PEEP 10 cm H2O group, with no statistically significant difference between the two groups [OR=0.997, 95%CI (0.495, 1.926), P=0.915]. Multivariate logistic regression analysis showed that PEEP was not an independent risk factor for PPCs [OR=0.920, 95%CI (0.587, 1.441), P=0.715]. ConclusionFor patients undergoing thoracoscopic lung surgery, intraoperative PEEP (5 cm H2O or 10 cm H2O) is not associated with the risk of PPCs during hospitalization after surgery, which needs to be further verified by prospective, large-sample randomized controlled studies.
ObjectiveTo investigate the relationship between pulmonary ventilation function (obstructive and restrictive ventilation dysfunction) and atherosclerosis, and explore the correlation between brachial-ankle pulse wave velocity (ba-PWV, an effective index for evaluating atherosclerosis) and pulmonary ventilation function.MethodsFrom January to August 2018, a total of 6403 healthy subjects who reported no major chronic diseases such as stroke, myocardial infarction, cor pulmonale or malignant tumor were selected. Past history such as smoking history, hypertension, diabetes, blood biochemistry, and blood hypersensitive C reactive protein (hs-CRP), hemodynamic indexes such as systolic pressure, diastolic pressure and ba-PWV, body measurement indexes such as height, weight, waist circumference and pulmonary ventilation function were collected. The relationship between ba-PWV and pulmonary ventilation function were evaluated.ResultsA total of 2433 subjects were included, including 916 males and 1517 females. Ba-PWV showed significant positive correlations with age, smoking index, waist circumference, systolic blood pressure, diastolic blood pressure, triglyceride, cholesterol, low density lipoprotein, hs-CRP, glycosylated hemoglobin, and significant negative correlations with height, percentage of forced vital capacity (FVC) in the predicted value (FVC%pred), forced expiratory volume in one second (FEV1), percentage of FEV1 in the predicted value (FEV1%pred), FEV1/FVC ratio and percentage of maximun midexpiratory flow (MMEF) in the predicted value (MMEF%pred). The ba-PWV was not correlated with weight, body mass index, FVC, MMEF, γ-glutamyl transpeptidase, high density lipoprotein, creatinine or uric acid. In multiple regression analysis using factors other than ba-PWV and respiratory function as adjustment variables, both FVC%pred and FEV1%pred showed significant negative relationships with ba-PWV (P<0.05).ConclusionsThe results indicate that FEV1/FVC, an indicator of airflow limitation, is not a predictor of ba-PWV. However, since ba-PWV showed significant negative relationship with FVC%pred and FEV1%pred, clinically assessment of arterial stiffness might be considered in individuals with impaired pulmonary ventilation.
【摘要】 目的 通过观察单肺通气患者术中氧合指数（oxygenation index，OI）、呼吸指数（respiratory index，RI）及动态肺顺应性（dynamic lung compliance，Cdyn）的变化，探讨高渗氯化钠溶液对术中单肺通气患者的肺保护作用。 方法 选择2009年12月-2011年2月完成的美国麻醉师协会分级为Ⅰ~Ⅲ级，心肺功能筛查、血常规、肝肾功能及凝血功能无明显异常，拟在全麻双腔气管插管下行开胸手术，术中需行单肺通气患者60例，随机分为高渗氯化钠组（A组）和对照组（B组），每组30例。A组在开始单肺通气后30 min快速输注7.5%高渗氯化钠溶液2 mL/kg，15 min内输注完毕，B组输注等量生理盐水，分别记录输注前（T1）、输注完毕时（T2）、输注后30 min（T3）、输注后1 h（T4）的OI、RI及Cdyn变化，并比较两组各时间点生命体征变化。 结果 两组患者OI、RI及Cdyn在T1、T2时差异无统计学意义（Pgt;0.05）；两组患者不同时间点平均动脉压、心率、脉搏血氧饱和度、中心静脉压、呼气末CO2分压比较差异无统计学意义（Pgt;0.05）；A组患者在T3、T4时的OI和Cdyn较B组明显升高，RI明显降低（Plt;0.05）；且A组患者在T3、T4时的OI和Cdyn较T1时明显增高，RI明显降低（Plt;0.05）。 结论 高渗氯化钠溶液能改善术中单肺通气患者的OI、RI及Cdyn，对肺功能有一定的保护作用。【Abstract】 Objective To observe the oxygenation index (OI), respiratory index (RI) and dynamic lung compliance (Cdyn) changes of the patients with one-lung ventilation, in order to determine if hypertonic saline has lung protective effects. Methods Sixty ASA Ⅰ-Ⅲ patients who needed one-lung ventilation during thoracotomy under general anesthesia with double-lunmen endotracheal tubes were chosen to be the study subjects. No obvious abnormalities were detected by cardiopulmonary function screening, blood test, hepatorenal function and blood coagulation examinations in these patients. They were randomly divided into hypertonic saline group (group A) and control group (group B) with 30 patients in each group. For patients in group A, 30 minutes after one-lung ventilation, infusion of 7.5% hypertonic saline solution at 2 mL/kg was carried out and completed in 15 minutes. For patients in group B, the same amount of saline solution was infused. We recorded OI, RI and Cdyn changes before the infusion (T1), on the completion of the infusion (T2), 30 minutes after the infusion (T3), and 1 hour after the infusion (T4). The changes of vital signs in patients of the two groups were compared. Results OI, RI and Cdyn were not significant different between the two groups at T1 and T2 (Pgt;0.05). Mean arterial pressure (MAP), heart rate (HR), SpO2, central venous pressure (CVP), and PetCO2 were not significant different between the two groups at all time points (Pgt;0.05). OI and Cdyn of group A patients were significantly higher than those of group B, while RI was significantly lower at T3 and T4 (Plt;0.05). Cdyn and OI of group A patients at T3 and T4 were significantly higher when compared with T1, and RI was significantly lower (Plt;0.05). Conclusion Hypertonic saline has the lung protection effect in patients with one-lung ventilation by improving OI, RI and Cdyn.
Objective To study the effects of hemodilution on oxygenation during one-lung ventilation(OLV).Methods Forty patients undergoing lung surgery with or without chronic obstructive pulmonary disease（COPD）were enrolled.The study was performed in the supine position before surgery.The tracheas were intubated with a double-lumen tube.OLV was initiated for 15 min.After 15 min of OLV，arterial and venous blood gas samples were collected and analyzed.The cardiac output (CO) was measured.Two-lung ventilation was reinstituted，and hemodilution was performed (6% hydroxyethyl starch，10 mL/kg).Subsequently，OLV was performed again for 15 min.Then arterial and venous blood gas samples were collected and analyzed.The cardiac output (CO) was measured.Results Hemodilution resulted in a significant and similar decrease in HB concentration in patients both with or without COPD.However，hemodilution resulted in a significant decrease in PaO2 in COPD patients rather than subjects without COPD.Conclusion Mild hemodilution impairs gas exchange during OLV in COPD patients.
Objective To assess the value of pulmonary ventilation test in evaluating the prognosis of cardiac surgery patients. Methods Data were collected retrospectively from consecutive patients with coronary heart disease or valvular disease, who were prepared for cardiac surgery in Zhongshan Hospital from January 2007 to December 2008. The main outcome indices were mortality of surgery, the prolonging time of using artificial airway ( ≥3 days) , and the prolonging time in intensive care units ( ICU) ( ≥5 days) . Then the relationship between the poor outcome and ventilation disorder was analyzed. Results In the 422 cases,the incidence of ventilation disorder was 55% , included 27. 5% restrictive ventilation disorder, 15. 6% obstructive ventilation disorder, and 11. 8% mixed ventilation disorder. And the severity of pulmonaryventilation disorder was mild of 34. 6% , moderate of 15. 2% , and severe of 5. 2% . Among the 42 patients who gave up surgery,50% were due to ventilation dysfunction, and the patients were prone to give up surgery with the deterioration of pulmonary function( P lt; 0. 001) . But comparing with the patients with normal pulmonary function, the risk of poor outcome after surgery did not significantly increase in the patients with ventilation disorder ( P gt; 0. 05 ) . The logistic regression analysis indicated that cardiopulmonary bypass ( CPB) was an absolute risk factor ( P lt; 0. 05) . Conclusions The incidence of ventilation disorder in patients with cardiac disease is quite high. Severe pulmonary ventilation disorder is the significant cause of giving up surgery, but may be not the absolute contraindication of cardiac surgery.
Objective To evaluate the effects of low-dose epinephrine on cerebral oxygen saturation (rScO2) and awakening time during one-lung ventilation (OLV) for thoracic surgery. Methods Thirty consecutive patients undergoing lobectomy from March to July 2016 in our hospital were randomly divided into an epinephrine group (n=15, 8 males and 7 females at an average age of 58.70±11.40 years) or a saline group (n=15, 7 males and 8 females at an average age of 57.00±11.40 years). They were continuously infused with 0.01 μg/(kg·min) epinephrine or saline after general induction. Hemodynamics was maintained ±20% of the baseline value. All patients were ventilated by a pressure control mode during OLV with tidal volume of 5-8 ml/kg and end-tidal carbon dioxide tension (EtCO2) of 35-45 mm Hg. Regional cerebral oxygen saturation (rScO2) was monitored using near-infrared spectroscopy (NIRS) continuously. Results Compared with the saline group, the epinephrine group had a high rScO2 during OLV, with a statisitical significance at OLV 40 min and 50 min (67.76%±4.64% vs. 64.08%±3.07%, P=0.016; 67.25%±4.34% vs. 64.20%±3.37%, P=0.040). In addition, the awakening time of patients in the epinephrine group was shorter than that of the saline group (P=0.004), and the awakening time was associated with the duration of low-dose rScO2 (r=0.374). Conclusion Continuous infusion of 0.01 μg/(kg·min) could improve the rScO2 during OLV and shorten awakening time in thoracic surgery.
单肺通气技术( OLV) 广泛应用于开胸手术, 该技术使手术侧肺萎陷, 非手术侧单肺通气, 目的是防止手术侧肺分泌物或血液流入健侧肺, 确保气道通畅, 防止交叉感染, 避免手术侧肺膨胀, 使肺保持安静以利于手术操作, 减轻对肺实质的损伤。随着手术日益走向微创时代, 对该技术的需求大量增加。
Objective To evaluate the association between pressure-controlled ventilation-volume guaranteed (PCV-VG) mode and volume-controlled ventilation (VCV) mode on postoperative pulmonary complications (PPCs) in patients undergoing thoracoscopic lung resection. Methods A retrospective cohort analysis of 329 patients undergoing elective thoracoscopic lung resection in West China Hospital of Sichuan University between September 2020 and March 2021 was conducted, including 213 females and 116 males, aged 53.6±11.3 years. American Society of Anesthesiologists (ASA) grade wasⅠ-Ⅲ. The patients who received lung-protective ventilation strategy during anesthesia were divided into a PCV-VG group (n=165) and a VCV group (n=164) according to intraoperative ventilation mode. Primary outcome was the incidence of PPCs during hospitalization. Results A total of 73 (22.2%) patients developed PPCs during hospitalization. The PPCs incidence of PCV-VG and VCV was 21.8% and 22.6%, respectively (RR=0.985, 95%CI 0.569-1.611, P=0.871). Multivariate logistic regression analysis showed that there was no statistical difference in the incidence of PPCs between PCV-VG and VCV mode during hospitalization (OR=0.846, 95%CI 0.487-1.470, P=0.553). Conclusion Among patients undergoing thoracoscopic lung resection, intraoperative ventilation mode (PCV-VG or VCV) is not associated with the risk of PPCs during hospitalization.