Evaluation of extravascular lung water index in critically ill patients based on lung ultrasound radiomics analysis combined with machine learning / 中华危重病急救医学

OBJECTIVE@#To explore lung ultrasound radiomics features which related to extravascular lung water index (EVLWI), and to predict EVLWI in critically ill patients based on lung ultrasound radiomics combined with machine learning and validate its effectiveness.@*METHODS@#A retrospective case-control study was conducted. The lung ultrasound videos and pulse indicated continuous cardiac output (PiCCO) monitoring results of critically ill patients admitted to the department of critical care medicine of the First Affiliated Hospital of Guangxi Medical University from November 2021 to October 2022 were collected, and randomly divided into training set and validation set at 8:2. The corresponding images from lung ultrasound videos were obtained to extract radiomics features. The EVLWI measured by PiCCO was regarded as the "gold standard", and the radiomics features of training set was filtered through statistical analysis and LASSO algorithm. Eight machine learning models were trained using filtered radiomics features including random forest (RF), extreme gradient boost (XGBoost), decision tree (DT), Naive Bayes (NB), multi-layer perceptron (MLP), K-nearest neighbor (KNN), support vector machine (SVM), and Logistic regression (LR). Receiver operator characteristic curve (ROC curve) was plotted to evaluate the predictive performance of models on EVLWI in the validation set.@*RESULTS@#A total of 151 samples from 30 patients were enrolled (including 906 lung ultrasound videos and 151 PiCCO monitoring results), 120 in the training set, and 31 in the validation set. There were no statistically significant differences in main baseline data including gender, age, body mass index (BMI), mean arterial pressure (MAP), central venous pressure (CVP), heart rate (HR), cardiac index (CI), cardiac function index (CFI), stroke volume index (SVI), global end diastolic volume index (GEDVI), systemic vascular resistance index (SVRI), pulmonary vascular permeability index (PVPI) and EVLWI. The overall EVLWI range in 151 PiCCO monitoring results was 3.7-25.6 mL/kg. Layered analysis showed that both datasets had EVLWI in the 7-15 mL/kg interval, and there was no statistically significant difference in EVLWI distribution. Two radiomics features were selected by using LASSO algorithm, namely grayscale non-uniformity (weight was -0.006 464) and complexity (weight was -0.167 583), and they were used for modeling. ROC curve analysis showed that the MLP model had better predictive performance. The area under the ROC curve (AUC) of the prediction validation set EVLWI was higher than that of RF, XGBoost, DT, KNN, LR, SVM, NB models (0.682 vs. 0.658, 0.657, 0.614, 0.608, 0.596, 0.557, 0.472).@*CONCLUSIONS@#The gray level non-uniformity and complexity of lung ultrasound were the most correlated radiomics features with EVLWI monitored by PiCCO. The MLP model based on gray level non-uniformity and complexity of lung ultrasound can be used for semi-quantitative prediction of EVLWI in critically ill patients.

Effects on extravascular lung water of lung protective ventilation strategy applied on piglets with acute respiratory distress syndrome induced by paraquat / 中华劳动卫生职业病杂志

Objective: To study the effects on extravascular lung water of lung protective ventilation strategy applying on piglets with acute respiratory distress syndrome (ARDS) induced by paraquat (PQ) under pulse indicating continuous cardiac output (PiCCO) monitoring. Methods: The piglets models with ARDS induced by PQ were established in June 2020 and all of them were received mechanical ventilation and divided into three groups according to tidal volume (V(T)) : small V(T) group (6 ml/kg) , middle V(T) group (10 ml/kg) and large V(T) group (15 ml/kg) , there were 5 piglets in each group. The positive end expiratory pressure (PEEP) were all setup on 10 cmH(2)O. The indexes such as arterial blood gas analysis, oxygenation index (OI) , extravascular lung water index (ELWI) and pulmonary vascular permeability index (PVPI) were monitored at time of before the model was established (baseline) , time of the model was established (t(0)) and 2 h (t(2)) , 4 h (t(4)) , 6 h (t(6)) after mechanical ventilation. Lung tissue were punctured at time of baseline, t(0) and t(6) to be stained by Hematoxylin-eosin (HE) staining and pulmonary pathology were observed under light microscopy. Results: The heart rate (HR) , mean arterial pressure (MAP) and partial pressure of carbon dioxide (PaCO(2)) of all groups were higher than the base value while the pH values, partial pressure of oxygen (PaO(2)) and OI were lower than the base value when the models were established (P<0.05) . After mechanical ventilation, the HR and MAP values of all groups at t(2), t(4) and t(6) were lower than t(0) while the PaCO(2) of t(4) and t(6) were all higher than t(0), the differences were statistically significant (P<0.05) . The PaO(2) and OI of all groups showed a trend of rising at first and then decreasing after mechanical ventilation. The MAP, PaO(2), PaCO(2) and OI of the middle V(T) group and large V(T) group were apparently lower than that of the small V(T) group at t(2), t(4) and t(6) (P<0.05) . The ELWI and PVPI at t(0) of all groups were higher than that of baseline (P<0.05) . The ELWI of the small V(T) group at t(6) were lower than t(0) of the same group and t(6) of the middle V(T) group and large V(T) group (P<0.05) . HE staining showed congestion and edema of alveolar tissue, swelling of capillaries, exudation of red blood cells and widening of alveolar septum in piglets after successful modeling. And further widening of alveolar septum and rupture of alveolar septum could be seen in the lung tissues of each group at t(6), and the injury was the slightest in the small V(T) group. Conclusion: The lung protective ventilation strategy can alleviate the extravascular lung water and ARDS induced by PQ and improve oxygenation.

Effect of rhubarb on extravascular lung water in patients with acute respiratory distress syndrome

Summary Objective: The aim of this study was to evaluate the effect of rhubarb on extravascular lung water (EVLW) in patients with acute respiratory distress syndrome (ARDS). Method: A total of 80 patients with ARDS were randomly divided into a treatment group (40 cases) and control group (40 cases). Patients in the treatment group received rhubarb (30.0 g/d) and patients in the control group received conventional therapy for seven consecutive days. Extravascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI) were determined using pulse contour cardiac output (PiCCO) technology, and the oxygenation index was measured by blood gas analysis at baseline and on days 3, 5 and 7 after treatment. Results: The oxygenation index was higher and the levels of EVLWI and PVPI were lower after treatment in the two groups; however, these indexes showed significant differences on the 5th and 7th days after rhubarb treatment compared with the results in the control group (p<0.05). Conclusion: Rhubarb can decrease EVLWI and PVPI, and improve oxygenation in patients with ARDS.

Effect of Paroxysmal Atrial Fibrillation on Parameters Monitored by Transpulmonary Thermodilution Method / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the effect of atrial fibrillation on the accuracy of parameters monitored by transpulmonary thermodilution method.</p><p><b>METHODS</b>Totally 12 patients from emergency intensive care unit with paroxysmal atrial fibrillation were enrolled. The hemodynamic parameters such as heart rate, mean arterial pressure, cardiac index, systemic vascular resistance index, intrathoracic blood volume index, and extravascular lung water index were monitored by transpulmonary thermodilution method before paroxysmal atrial fibrillation and during atrial fibrillation, the number of B-lines was detected by lung ultrasonography before and during paroxysmal atrial fibrillation. The changes of all the parameters were analyzed.</p><p><b>RESULTS</b>When the paroxysmal atrial fibrillation happened, the heart rate increased significantly [(123.3±20.0) beat/min vs. (98.9±12.3) beat/min, P=0.006]; the mean arterial pressure [(86.9±10.2) mmHg vs. (93.0±12.5) mmHg, P=0.058], cardiac index [(2.82±0.62) L/(min·m(2)) vs. (3.31±1.02) L/(min·m(2)), P=0.058] and systemic vascular resistance index [(2254±947) dyn·s·cm(-5)·m(2) vs. (2302±828) dyn·s·cm(-5)·m(2), P=0.351] had no obvious change; however, the intrathoracic blood volume index significantly increased [(1333±90) ml/m(2) vs. (937±111) ml/m(2), P<0.001]; extravascular lung water index also increased significantly [(16.1±1.1) ml/kg vs. (6.5±1.9) ml/kg, P<0.001]. No significant difference was found in the number of B-lines detected by lung ultrasonography before and during atrial fibrillation (10.0±4.2 vs. 9.4±4.4, P=0.180).</p><p><b>CONCLUSION</b>Both intrathoracic blood volume and extravascular lung water monitored by transpulmonary thermodilution method were overvalued during paroxysmal atrial fibrillation, which may mislead the clinical judgment and decision-making.</p>

Comparative effects of propofol and nitroglycerine on efficacy of rewarming in patients undergoing on-pump coronary artery bypass grafting.

Objectives: To compare the effects of propofol and nitroglycerine (NTG) on the efficacy of rewarming, extra volume added during cardiopulmonary bypass and extravascular lung water (EVLW) in patients undergoing on‑pump coronary artery bypass grafting. Materials and Methods: A prospective, randomized, blinded trial, twenty adult patients were randomly assigned to receive either NTG infusion (NTG group) or propofol infusion (propofol group) during rewarming. Results: After drop in temperature at the end of surgery and till 24 h were significantly less in propofol group compare to NTG group (P < 0.025). Extra volume added during cardiopulmonary bypass and net crystalloid balance till 24 h was less in the propofol group (P < 0.003). There was no difference in EVLW and postoperative outcome. Conclusions: Propofol use during moderate hypothermic cardiopulmonary bypass is associated with less after drop in temperature and less requirement of extra fluid during the perioperative period.

Prognostic value of Picco monitoring combined with plasma microRNA-150 detection in septic shock patients / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To assess the prognostic value of pulse indicator continuous cardiac output (Picco) monitoring combined with plasma microRNA-150 detection in septic shock patients.</p><p><b>METHODS</b>Clinical data of 48 patients with septic shock admitted in General Intensive Care Unit (GICU), Shanghai First People's Hospital Songjiang Branch Affiliated to Shanghai Jiaotong University from August 2012 to August 2014 were analyzed retrospectively. The plasma levels of microRNA-150 in 48 patients at admission were assayed by qRT-PCR; and Picco monitoring was performed to record hemodynamic changes. The correlation of microRNA-150 or Picco parameters with prognosis of patients was assessed by univariate analysis and multivariate logistic analysis. Spearman correlation test showed the relationship between microRNA-150 and Picco parameters. Finally, the clinical value of combining microRNA-150 with Picco monitoring to predict the outcome of septic shock patients was analyzed by ROC curves.</p><p><b>RESULTS</b>Twenty-three patients survived and 25 died in 28 d after admission in GICU. Compared with survival patients, microRNA-150 was significantly lower in fatal patients (t=-10.32, P<0.05). Univariate analysis showed that low microRNA-150 level was a risk factor for poor prognosis(OR=2.176,95% CI:1.121-4.223, P<0.05). Compared with fatal cases, the cardiac index of survival patients was higher, while EVLWI and PVPI were lower. MicroRNA-150 level was positively correlated with cardiac index (r=0.712, P<0.05), negatively correlated with EVLWI and PVPI (r=-0.622 and-0.689, both P<0.05). ROC curves showed a satisfactory diagnostic efficiency of combining microRNA-150 with Picco monitoring.</p><p><b>CONCLUSION</b>Lower microRNA-150 may indicate a poor prognosis, and Picco monitoring combined with microRNA 150 detection may improve the prognostic efficiency in septic shock patients.</p>

Observation on the best dose of methylprednisolone improving lung injury in swine with paraquat intoxication / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the best dose of methylprednisolone improving lung injury in swine with paraquat intoxication.</p><p><b>METHODS</b>Acute lung injury (ALI/ARDS) model was made by an intraperitoneal injection of a large dose of 20%PQ solution20 millilitres in swine. Then 24 swine were randomly divided into 4 groups: exposed PQ control group, 5 mg/kg of methylprednisolone group, 15 mg/kg of methylprednisolone group, 30 mg/kg of methylprednisolone group. All groups were based on the conventional rehydration for intervention, Arterial blood samples were collected before modeling and 0, 12, 24, 36 hours after different processing for blood gas analysis. At the same time heart rate (HR), mean arterial pressure (MAP), extravascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI) were measured by using PICCO (pulse indicator continuous cardiac output), lung tissue was obtained by punctureneedle to produce lung biopsy, then observe the pathological changes of lung tissue in the microscope.</p><p><b>RESULTS</b>1. Comparison between groups: there is no significant difference about extravascular lung water index (EVLWI) and semi-quantitative score of lung tissue pathology in four groups (P > 0.05) before modeling, so is t0, there is significant difference at about extravascular lung water index and semi-quantitative score of lung tissue pathology 12 h, 24 h and 36 h after different processing (P < 0.05). Within the group: EVLWI and semi-quantitative score of Lung tissue pathology in four groups significantly increased when the model was made (P < 0.05), after different processing, EVLWI and semi-quantitative score of Lung tissue pathology in exposed PQ control group kept going up, in other three groups, EVLWI and semi-quantitative score of lung tissue pathology went down first and then went up, there is significant difference compared with t0 (P < 0.05). 2. Comparison between groups: there is no significant difference about oxygenation index in four groups (P > 0.05) before modeling, so is t0, there is significant difference about oxygenation at 12 h, 24 h and 36 h after different processing (P < 0.05). Within the group: oxygenation index in four groups significantly decreased when the model was made (P < 0.05), after different processing, oxygenation index in exposed PQ control group kept going down, in other three groups, it showed a downward trend after the first rise, there is significant difference compared with t0 (P < 0.05). 3. After medication for 36h, correlation analysis showed that EVLWI were negatively associated with oxygenation index (r = -0.427, P = 0.022) and positively associated with semi-quantitative score of Lung tissue pathology (r = 0.903, P = 0.034).</p><p><b>CONCLUSION</b>Methylprednisolone can obviously relieve lung injury caused by paraquat poisoning and improve oxygenation. After the model was made, within 24 hours, 30 mg/kg of methylprednisolone have advantage for the PQ poisoning swine, but 15mg/kg of methylprednisolone is best for improving lung injury induced by paraquat intoxication within 24 hours to 36 hours.</p>

Effects of continuous blood purification on extravascular lung water and respiratory function in patients with extrapulmonary acute respiratory distress syndrome / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the effects of continuous blood purification (CBP) on extravascular lung water and respiratory function in patients with extrapulmonary acute respiratory distress syndrome (ARDSexp).</p><p><b>METHODS</b>The data of 31 patients with ARDSexp admitted in our department were retrospectively analyzed.Sixteen of the patients received CBP, and the other 15 patients did not (control group). The level of extravascular lung water index (EVLWI), pulmonary vascular permeability index (PVPI), and respiratory function were measured before and after CPB.</p><p><b>RESULTS</b>The mortality rate was significantly lower in CBP group than in the control group (12.5% vs 33.3%, P<0.05). The patients in CPB group showed markedly earlier and significantly greater improvements in EVLWI, PVPI, PaO2/FiO, and respiratory function than the control patients (P<0.05).</p><p><b>CONCLUSION</b>CBP can reduce EVLWI and PVPI, improve pulmonary compliance and oxygenation, and reduce mortality rate in patients with ARDSexp.</p>

Advances in the research of extravascular lung water after severe burn / 中华烧伤杂志

Pulmonary edema frequently occurs after severe burn. It not only impairs pulmonary function directly, but also can induce or exacerbate other pulmonary complications such as lung infection, acute lung injury ( ALI), and ARDS. Extravascular lung water (EVLW) is closely related to the pulmonary edema. Dynamical monitor of EVLW has been used to predict and quantify the degree of pulmonary edema clinically. This review focuses on the recent progresses at home and abroad on the formation mechanism, monitoring approach, and prevention and treatment of EVLW after severe burn injury.

Significance of extravascular lung water index, pulmonary vascular permeability index, and in- trathoracic blood volume index in the differential diagnosis of burn-induced pulmonary edema / 中华烧伤杂志

<p><b>OBJECTIVE</b>To appraise the significance of extravascular lung water index (EVLWI), pulmonary vascular permeability index (PVPI), and intrathoracic blood volume index (ITBVI) in the differential diagnosis of the type of burn-induced pulmonary edema.</p><p><b>METHODS</b>The clinical data of 38 patients, with severe burn hospitalized in our burn ICU from December 2011 to September 2014 suffering from the complication of pulmonary edema within one week post burn and treated with mechanical ventilation accompanied by pulse contour cardiac output monitoring, were retrospectively analyzed. The patients were divided into lung injury group ( L, n = 17) and hydrostatic group (H, n = 21) according to the diagnosis of pulmonary edema. EVLWI, PVPI, ITBVI, oxygenation index, and lung injury score ( LIS) were compared between two groups, and the correlations among the former four indexes and the correlations between each of the former three indexes and types of pulmonary edema were analyzed. Data were processed with t test, chi-square test, Mann-Whitney U test, Pearson correlation test, and accuracy test [receiver operating characteristic (ROC) curve].</p><p><b>RESULTS</b>There was no statistically significant difference in EVLWI between group L and group H, respectively (12.9 ± 3.1) and (12.1 ± 2.1) mL/kg, U = 159.5, P > 0.05. The PVPI and LIS of patients in group L were respectively 2.6 ± 0.5 and (2.1 ± 0.6) points, and they were significantly higher than those in group H [1.4 ± 0.3 and (1.0 ± 0.6) points, with U values respectively 4.5 and 36.5, P values below 0.01]. The ITBVI and oxygenation index of patients in group L were respectively (911 197) mL/m2 and (136 ± 69) mmHg (1 mmHg = 0.133 kPa), which were significantly lower than those in group H [(1,305 ± 168) mL/m2 and (212 ± 60) mmHg, with U values respectively 21.5 and 70.5, P values below 0.01]. In group L, there was obviously positive correlation between EVLWI and PVPI, or EVLWI and ITBVI (with r values respectively 0.553 and 0.807, P < 0.05 or P < 0.01), and there was obviously negative correlation between oxygenation index and EVLWI, or oxygenation index and PVPI (with r values respectively -0.674 and -0.817, P values below 0.01). In group H, there was obviously positive correlation between EVLWI and ITBVI (r = 0.751, P < 0.01) but no obvious correlation between EVLWI and PVPI, oxygenation index and EVLWI, or oxygenation index and PVPI (with r values respectively -0.275, 0.197, and 0:062, P values above 0.05). The total area under ROC curve of PVPI value for differentiating the type of pulmonary edema was 0.987 [with 95% confidence interval (CI) 0.962-1.013, P < 0.01], and 1.9 was the cutoff value with sensitivity of 94.1% and specificity of 95.2% . The total area under ROC curve of ITBVI value for differentiating the type of pulmonary edema was 0.940 (with 95% CI 0.860-1.020, P < 0.01), and 1,077. 5 mL/m2 was the cutoff value with sensitivity of 95.2% and specificity of 88.2%.</p><p><b>CONCLUSIONS</b>EVLWI, PVPI, and ITBVI have an important significance in the differential diagnosis of the type of burn-induced pulmonary edema, and they may be helpful in the early diagnosis and management of burn-induced pulmonary edema.</p>

Role of central venous pressure, global end diastolic volume index and extravascular lung water index in evaluating fluid resuscitation in patients with septic shock / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the role of central venous pressure (CVP), global end diastolic volume index (GEDI) and extravascular lung water index (ELWI) monitoring in patients with septic shock during fluid resuscitation by pulse induced continuous cardiac output (PiCCO) test.</p><p><b>METHODS</b>Forty-six patients with severe sepsis and septic shock were enrolled in this study. Hemodynamic monitoring was performed during fluid resuscitation and the data including CVP, GEDI and ELWI were collected to analyze their relationship and the clinical values.</p><p><b>RESULTS</b>In patients with septic shock, CVP showed a weak linear correlation with GEDI during fluid resuscitation (r=0.137, P=0.009). In the subgroups stratified with CVP cut-off values of 8 mmHg and 12 mmHg, the correlation coefficient between CVP and GEDI was 0.149 (P=0.029) in CVP<8 mmHg group, 0.075 (P=0.462) in 8 mmHg ≤ CVP ≤ 12 mmHg group, and 0.049 (P=0.726) in CVP>12 mmHg group. In the total of 367 data groups obtained, CVP showed no linear correlation with ELWI (r=0.040, P=0.445). In the CVP subgroups, CVP and ELWI were weakly correlated in CVP<8 mmHg group (r=0.221, P=0.001), but they showed no correlations in 8 mmH g≤ CVP ≤ 12 mmHg and CVP>12 mmHg groups (r=-0.047, P=0.646; r=0.042, P=0.765).</p><p><b>CONCLUSION</b>There is no significant linear correlation between CVP and GEDI or between CVP and ELWI in patients with septic shock. CVP can not reflect the circulatory blood volume or the degree of pulmonary edema.</p>

Recent trend in cardiac output monitoring and trans-cardiopulmonary thermodilution-derived hemodynamic parameters

Currently, hemodynamic monitoring system is developing rapidly, with many different devices now available, which makes anesthesiologists feel somewhat confused by the various possibilities and issue of noninvasiveness. By the order of degree of invasiveness, these devices can be classified into the highly invasive pulmonary artery catheter and the completely noninvasive bioimpedance/bioreactance technique and Doppler echocardiography. Recently, trans-cardiopulmonary thermodilution-derived hemodynamic parameters, such as global end-diastolic volume, global ejection fraction, cardiac function index, extravascular lung water, pulmonary vascular permeability index and its cardiac output, are available in anesthetic practice by PiCCO(R)(Pulsion Medical Systems) and VolumeView(R) (Edwards Life Sciences). This article provides objective review of the monitoring systems, as well as the advantages and limitations, in order to offer better management of the critically ill patients undergoing surgery.

Pulse indicator continuous cardiac output measurement-guided treatment aids two pediatric patients with severe acute pancreatitis complicated with acute respiratory distress syndrome / 中华儿科杂志

<p><b>OBJECTIVE</b>To evaluate the clinical value of the pulse indicator continuous cardiac output (PiCCO) system in patients with severe acute pancreatitis (SAP) complicated with acute respiratory distress syndrome (ARDS).</p><p><b>METHOD</b>Two cases of SAP with ARDS were monitored using PiCCO during comprehensive management in the Pediatric Intensive Care Unit (PICU) of Shengjing Hospital, China Medical University. To guide fluid management, the cardiac index (CI) was measured to assess cardiac function, the global end-diastolic volume index (GEDVI) was used to evaluate cardiac preload, and the extravascular lung water index (EVLWI) was used to evaluate the pulmonary edema.</p><p><b>RESULT</b>Case 1 was diagnosed with type L2 acute lymphoblastic leukemia (intermediate risk) and received the sixth maintenance phases of chemotherapy this time. After a 1-week dosage of chemotherapeutic drugs (pegaspargase and mitoxantrone), he suffered SAP combined with ARDS. Except comprehensive treatment (life supporting, antibiotic, etc.) and applying continuous veno-venous hemodiafiltration (CVVHDF) to remove inflammatory mediators. PiCCO monitor was utilized to guide fluid management. During the early stage of PiCCO monitoring, the patient showed no significant manifestations of pulmonary edema in the bedside chest X-ray (bedside ultrasound showed left pleural effusion), and had an oxygenation index 223 mmHg (1 mmHg = 0.133 kPa), GEDVI 450 ml/m², and ELVWI 7 ml/kg. We increased cardiac output to increase tissue perfusion and dehydration speed of CVVHDF was set at 70 ml/h. Two hours later, GEDVI significantly increased to 600 ml/m² and ELVWI significantly increased to 10 ml/kg, the oxygenation index declined to 155 mmHg, the bedside chest X-ray showed a significant decrease of permeability (right lung) and PEEP was adjusted to 5 cmH₂O (1 cmH₂O = 0.098 kPa), indicating circulating overload. ARDS subsequently occurred, upon which the fluid infusion was halted, the dehydration rate of CVVHDF raised (adjusted to 100-200 ml/h). On day 3 in the PICU, EVLWI dropped to 6 ml/kg, GEDVI dropped to 370 ml/m², and the oxygenation index increased to 180 mmHg. On day 8, the patient was successfully weaned from the ventilator. However, on day 9, the patient reverted to mechanical ventilation due to secondary infection. On day 30, the patient was discharged for voluntarily giving up treatment. Late follow-up results showed that the patient was dead one day after giving up treatment. Case 2 was admitted due to SAP induced by overeating one day before admission. On day 2, the patient showed dyspnea and oxygen saturation decreased to 80%. We applied mechanical ventilation, CVVHDF to remove inflammatory mediators and PiCCO to guide fluid management. According to the initial data of PiCCO, EVLWI was 9 ml/kg, GEDVI was 519 ml/m², the oxygenation index was 298 mmHg, the bedside chest X-ray showed decreased permeability and PEEP was adjusted to 5 cmH₂O, suggesting the existence of ARDS. During treatment, the dehydration speed of CVVHDF was set at 50 ml/h to maintain the balance of fluid input and output. Two hours after PiCCO monitoring, the oxygenation index decreased to 140 mmHg, GEDVI 481 ml/m², EVLWI 9 ml/kg, thus the dehydration speed of CVVHDF was increased (up to 100 ml/h). On day 4 in the PICU, EVLWI was 9 ml/kg, GEDVI was 430 ml/m², oxygenation index was 394 mmHg, and the bedside chest X-ray showed that permeability was higher. On day 5, the patient was transferred from PiCCO. On day 30, the patient recovered and was discharged.</p><p><b>CONCLUSION</b>PiCCO monitoring can provide real-time surveillance of cardiac function, cardiac preload and afterload, and extravascular lung water in pediatric patients with SAP combined with ARDS. These results are clinically significant for the rescue of critically ill patients with ARDS or shock.</p>

Effects of sivelestat on acute lung injury in dogs with severe burn-blast combined injury / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe and study the effects of sivelestat on acute lung injury in dogs with severe burn-blast combined injury.</p><p><b>METHODS</b>Thirty-two male beagle dogs of clean grade were divided into 4 groups: uninjured group (U), combined injury control group (CIC), combined injury+low dose of sivelestat group (CI+LS), combined injury+high dose of sivelestat group (CI+HS), with 8 dogs in each group. Except for the dogs in group U which were not injured, the dogs in the other 3 groups were inflicted with severe burn-blast combined injury. According to the Parkland formula, the dogs in groups U and CIC were infused with physiological saline, and the dogs in groups CI+LS and CI+HS received sivelestat with the dosage of 0.5 and 2.0 mg·kg(-1)·h(-1) respectively in addition. The 24 h continuous intravenous infusion was carried out for 2 days. At post injury hour (PIH) 6, CT scanning was conducted to observe the lung damage. At PIH 2, 6, 12, 24, and 48, mean arterial pressure (MAP), respiratory rate (RR), extra vascular lung water (EVLW), pulmonary vascular permeability index (PVPI), PaO2, and PaCO2 were measured; the contents of neutrophil elastase (NE), IL-8, and TNF-α were determined by ELISA. At PIH 48, all the dogs were sacrificed, and the lung tissues were harvested to measure the wet to dry lung weight ratio. The same examination was carried out in the dogs of the group U at the same time points. Data were processed with analysis of variance of repeated measurement and LSD test.</p><p><b>RESULTS</b>(1) CT images showed some exudative lesions in the dogs of groups CIC and CI+LS but not in the dogs of groups U and CI+HS. (2) No statistically significant differences were observed in MAP at each time point between every two groups (with P values above 0.05). The RR values in group U were significantly different from those of the other 3 groups at all time points (with P values below 0.05). The values of EVLW and PVPI in 3 combined injury groups were significantly different from those in group U at PIH 6, 12, 24, and 48 (with P values below 0.05). The values of RR and EVLW in group CI+LS were significantly different from those in group CI+HS at PIH 12, 24, and 48 (with P values below 0.05). The values of PVPI in group CI+LS were significantly different from those in group CI+HS at PIH 24 and 48 (with P values below 0.05). (3) The levels of PaO2 and PaCO2 showed significant differences between group U and the other 3 groups at each time point (with P values below 0.05). The levels of PaO2 in group CI+LS were significantly different from those in CI+HS group at PIH 12, 24, and 48 (with P values below 0.05). The level of PaCO2 showed significant differences between group CI+LS and group CI+HS at PIH 24 and 48 (with P values below 0.05). (4) The contents of NE (except for PIH 2), TNF-α, and IL-8 showed significant differences between group U and the other 3 groups at each time point (P < 0.05 or P < 0.01). At PIH 2, 6, 12, 24, and 48, the contents of NE in groups U, CIC, CI+LS, and CI+HS were respectively (69 ± 21), (83 ± 24), (80 ± 20), (75 ± 17), (72 ± 27) pg/mL; (66 ± 24), (196 ± 20), (231 ± 26), (252 ± 25), (266 ± 22) pg/mL ; (71 ± 22), (180 ± 27), (214 ± 21), (194 ± 24), (218 ± 20) pg/mL; (68 ± 22), (136 ± 24), (153 ± 22), (146 ± 26), (150 ± 28) pg/mL. NE values in group CI+HS were statistically different from those in groups CIC and CI+LS at PIH 6, 12, 24, and 48 (with P values below 0.05). The contents of TNF-α in group CI+LS were statistically different from those in groups CIC and CI+HS at PIH 24 and 48 (with P values below 0.05). The contents of IL-8 in group CI+LS were statistically different from those in group CI+HS at PIH 24 and 48 (with P values below 0.05). (5) At PIH 48, the wet to dry lung weight ratio of group CIC was statistically different from that in group CI+LS or group CI+HS (with P values below 0.05); there was also difference between group CI+LS and group CI+HS (P < 0.05).</p><p><b>CONCLUSIONS</b>Sivelestat, especially in a high dose, exerts a protective effect in acute lung injury after burn-blast combined injury through improving the index of blood gas analysis, ameliorating pulmonary edema, and lowering the production of pro-inflammatory mediators.</p>

Effects of lung protective ventilation strategy combined with lung recruitment maneuver on patients with severe burn complicated with acute respiratory distress syndrome / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the effects of lung protective ventilation strategy combined with lung recruitment maneuver on ARDS complicating patients with severe burn.</p><p><b>METHODS</b>Clinical data of 15 severely burned patients with ARDS admitted to our burn ICU from September 2011 to September 2013 and conforming to the study criteria were analyzed. Right after the diagnosis of acute lung injury/ARDS, patients received mechanical ventilation with lung protective ventilation strategy. When the oxygenation index (OI) was below or equal to 200 mmHg (1 mmHg = 0. 133 kPa), lung recruitment maneuver was performed combining incremental positive end-expiratory pressure. When OI was above 200 mmHg, lung recruitment maneuver was stopped and ventilation with lung protective ventilation strategy was continued. When OI was above 300 mmHg, mechanical ventilation was stopped. Before combining lung recruitment maneuver, 24 h after combining lung recruitment maneuver, and at the end of combining lung recruitment maneuver, variables of blood gas analysis (pH, PaO2, and PaCO2) were obtained by blood gas analyzer, and the OI values were calculated; hemodynamic parameters including heart rate, mean arterial pressure (MAP), central venous pressure (CVP) of all patients and the cardiac output (CO), extravascular lung water index (EVLWI) of 4 patients who received pulse contour cardiac output (PiCCO) monitoring were monitored. Treatment measures and outcome of patients were recorded. Data were processed with analysis of variance of repeated measurement of a single group and LSD test.</p><p><b>RESULTS</b>(1) Before combining lung recruitment maneuver, 24 h after combining lung recruitment maneuver, and at the end of combining lung recruitment maneuver, the levels of PaO2 and OI of patients were respectively (77 ± 8), (113 ± 5), (142 ± 6) mmHg, and (128 ± 12), (188 ± 8), (237 ± 10) mmHg. As a whole, levels of PaO2 and OI changed significantly at different time points (with F values respectively 860. 96 and 842. 09, P values below 0. 01); levels of pH and PaCO2 showed no obvious changes (with F values respectively 0.35 and 3.13, P values above 0.05). (2) Levels of heart rate, MAP, CVP of all patients and CO of 4 patients who received PiCCO monitoring showed no significant changes at different time points (with F values from 0. 13 to 4. 26, P values above 0.05). Before combining lung recruitment maneuver, 24 h after combining lung recruitment maneuver, and at the end of combining lung recruitment maneuver, the EVLWI values of 4 patients who received PiCCO monitoring were respectively (13.5 ± 1.3), (10.2 ± 1.0), (7.0 ± 0.8) mL/kg ( F =117.00, P <0.01). (3) The patients received mechanical ventilation at 2 to 72 h after burn, lasting for 14-32 (21 ± 13) d. At post injury day 3-14 (7 ± 5) d, lung recruitment maneuver was applied for 2-5 (3.0 ± 2.0) d. All 15 patients recovered without other complications.</p><p><b>CONCLUSIONS</b>Lung protective ventilation strategy combining lung recruitment maneuver can significantly improve the oxygenation in patients with severe burn complicated with ARDS and may therefore improve the prognosis.</p>

Changes of the hemodynamics and extravascular lung water after different-volume fluid resuscitation in a piglet model of endotoxic shock / 中华儿科杂志

<p><b>OBJECTIVE</b>Practice recommendations have evolved, and consensus now exists among leading organizations such as the American College of Critical Care Medicine (ACCM) and Surviving Sepsis Campaign that fluid infusion is best initiated with boluses of 20 ml/kg, commonly requires 40-60 ml/kg but can be as much as 200 ml/kg if the liver is not enlarged and/or rales are not heard. The present study aimed to investigate and compare the changes of the hemodynamics and extravascular lung water after higher volume fluid resuscitation in a piglet model of endotoxic shock.</p><p><b>METHOD</b>Twenty piglets were used for establishing animal models of endotoxic shock by intravenous infusing lipopolysaccharide (LPS). The experimental animals were divided into three groups according to the volume infused during the resuscitation. The three groups received different volume of saline in less than an hour after endotoxic shock. By the PiCCO plus system, we investigated the changes of hemodynamics and extravascular lung water.</p><p><b>RESULT</b>After fluid resuscitation, global end diastolic volume inder, (GEDI) and intrathoracic blood volume index, (ITBI) markedly increased in the group of 80 ml/kg and 120 ml/kg, but there was no change in the group of 40 ml/kg. GEDI: Fifteen min after fluid resuscitation R1 was (261 ± 64) ml/m(2), R2 (457 ± 124) ml/m(2), R3 (413 ± 148) ml/m(2), 4 h R1 (251 ± 68) ml/m(2), R2 (422 ± 70) ml/m(2), R3 (470 ± 160) ml/m(2); ITBI: Fifteen min after fluid resuscitation R1 was (335 ± 69) ml/m(2), R2 (550 ± 179) ml/m(2), R3 (520 ± 183) ml/m(2), 4 h R1 (314 ± 84) ml/m(2), R2 (534 ± 96) ml/m(2), R3 (594 ± 200) ml/m(2) (R1 vs. R2 vs. R3, F = 26.373, P < 0.05; R1 vs. R2, R1 vs. R3, P < 0.05; R2 vs. R3, P > 0.05). CI of all three groups significantly decreased when the models were established. After fluid resuscitation, the base level was maintained in the group of 80 ml/kg and 120 ml/kg, but it was under the basic level in the group of 40 ml/kg.Fifteen min after fluid resuscitation R1 was (4.5 ± 0.7) L/(min·m(2)), R2 (6.4 ± 2.2) L/(min·m(2)), R3 (5.5 ± 0.7) L/(min·m(2)), 4 h R1 (4.1 ± 1.0) L/(min·m(2)), R2 (5.2 ± 0.9) L/(min·m(2)), R3 (5.1 ± 0.8) L/(min·m(2)). There was no significant difference in CI between these two groups (P > 0.05).ELWI of the group of 80 ml/kg and 120 ml/kg were still higher than that of the group of 40 ml/kg, 15 min after fluid resuscitation R1 was (19.2 ± 8.6) ml/kg, R2 (29.2 ± 5.5) ml/kg, R3 (23.4 ± 8.2) ml/kg, 4 h R1 (18.3 ± 6.5) ml/kg, R2 (23.8 ± 2.6) ml/kg, R3 (21.4 ± 3.9) ml/kg, but there was no significant difference in ELWI among the groups (P > 0.05).</p><p><b>CONCLUSION</b>Resuscitation with higher volume of fluid infusion in the early stage of endotoxic shock was more efficient to increase the preload and maintain the cardiac output at the baseline level, and might reduce the need for vasoactive agents. Meanwhile, resuscitation with higher volume of fluid in the early stage of endotoxic shock did not sharply increase the extravascular lung water.</p>

Effects of chest compressions on cardiorespiratory function in a non-arrested porcine model / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The effects of chest compressions to hemodynamic and respiratory parameters during hands-only cardiopulmonary resuscitation (CPR) in a non-arrested patient who suddenly collapses are confusing. In this research, we investigated the effects of chest compressions in a non-arrested porcine model.</p><p><b>METHODS</b>Fourteen male domestic pigs were randomized into sham control group (SHAM group, only anesthetized and instrumented without chest compression, n = 6) or chest compression group (CC group, 2 minutes of chest compressions, n = 8). Continuous hemodynamic parameters, dynamic lung compliance (Cdyn), and blood gas analysis outcomes were recorded. Serum levels of catecholamine were measured at baseline and 2 minutes, 30 minutes, 4 hours, and 24 hours after chest compressions. Chest computed tomography (CT) was performed at 30 minutes and 24 hours. Conventional histopathology evaluation was performed.</p><p><b>RESULTS</b>After two minutes of chest compressions in the CC group, heart rate and extravascular lung water increased significantly; mean arterial pressure, stroke volume, and global ejection fraction significantly decreased. Cdyn significantly decreased to valley levels at 30 minutes and slowly recovered. Compared with the baseline, serum levels of catecholamine significantly increased at 2 minutes and rapidly decreased 24 hours later. At 30 minutes after chest compressions, chest CT showed local exudation, which was absorbed 24 hours later.</p><p><b>CONCLUSIONS</b>This research showed that 2 minutes of chest compressions causes various heart and lung tissue damage in the normal a normal porcine model. It also impacts the hemodynamic and Cdyn.</p>

Evaluation of respiratory dysfunction in a pig model of severe acute dichlorvos poisoning / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Respiratory failure is the main cause of death in acute organophosphorus pesticide poisoning. In this study, a pulse-induced contour cardiac output monitor was used to evaluate the respiratory status in a pig model of acute dichlorvos poisoning.</p><p><b>METHODS</b>Twenty female pigs were randomly allocated to dichlorvos (n = 7), atropine (n = 7), and control (n = 6) groups. In the dichlorvos group, pigs were administered 80% emulsifiable dichlorvos (100 mg/kg) via a gastric tube. In the atropine group, pigs were similarly administered dichlorvos, and 0.5 hours later, atropine was injected to attain and maintain atropinization. The control group was administered saline solution. Arterial blood gas was measured at 0, 0.5, 1, 2, 4, and 6 hours post-injection. The extravascular lung water index and pulmonary vascular permeability index were recorded by the pulse-induced contour cardiac output monitor. At termination of the study, the animals were euthanized, the lung wet-to-dry weight ratio was determined, and histopathology was observed.</p><p><b>RESULTS</b>In the dichlorvos group, the extravascular lung water index and pulmonary vascular permeability index were substantially increased from 0.5 hours and were particularly high within 1 hour. In the atropine group, these indices increased initially, but decreased from the 1-hour mark. The control group exhibited no obvious changes. In both the dichlorvos and atropine groups, the extravascular lung water index was negatively correlated with partial pressure of oxygen/fraction of inspiration oxygen (PO2/FiO2) and positively correlated with the pulmonary vascular permeability index. Compared with the control group, the lung wet-to-dry weight ratio markedly increased and the histopathological findings obviously changed in the dichlorvos group, but only mildly increased and changed, respectively, in the atropine group.</p><p><b>CONCLUSION</b>The extravascular lung water index is an appropriate and valuable parameter for assessment of respiratory function in acute dichlorvos poisoning.</p>

Sildenafil prevents the increase of extravascular lung water and pulmonary hypertension after meconium aspiration in newborn piglets

Meconium aspiration syndrome causes respiratory failure after birth and in vivo monitoring of pulmonary edema is difficult. The objective of the present study was to assess hemodynamic changes and edema measured by transcardiopulmonary thermodilution in low weight newborn piglets. Additionally, the effect of early administration of sildenafil (2 mg/kg vo, 30 min after meconium aspiration) on this critical parameter was determined in the meconium aspiration syndrome model. Thirty-eight mechanically ventilated anesthetized male piglets (Sus scrofa domestica) aged 12 to 72 h (1660 ± 192 g) received diluted fresh human meconium in the airway in order to evoke pulmonary hypertension (PHT). Extravascular lung water was measured in vivo with a PiCCO monitor and ex vivo by the gravimetric method, resulting in an overestimate of 3.5 ± 2.3 mL compared to the first measurement. A significant PHT of 15 Torr above basal pressure was observed, similar to that of severely affected humans, leading to an increase in ventilatory support. The vascular permeability index increased 57 percent, suggesting altered alveolocapillary membrane permeability. Histology revealed tissue vessel congestion and nonspecific chemical pneumonitis. A group of animals received sildenafil, which prevented the development of PHT and lung edema, as evaluated by in vivo monitoring. In summary, the transcardiopulmonary thermodilution method is a reliable tool for monitoring critical newborn changes, offering the opportunity to experimentally explore putative therapeutics in vivo. Sildenafil could be employed to prevent PHT and edema if used in the first stages of development of the disease.

Como determinar a volemia em pacientes com lesão pulmonar aguda/síndrome do desconforto respiratório agudo / Determining blood volume in patients with acute lung injury/acute respiratory distress syndrome

A morbidade e a mortalidade de pacientes com lesão pulmonar aguda (LPA) ou síndrome do desconforto respiratório agudo (SDRA) permanecem elevadas. Devido às alterações na membrana alvéolo-capilar, assim como uma possível elevação da pressão hidrostática, a reposição volêmica passa a ter extrema importância. Para tal, são necessárias avaliações precisas do estado volêmico e da predição da resposta hemodinâmica.Estudos recentes enfatizam a indução de um balanço negativo em pacientes com LPA que não se encontram em choque circulatório. Novos estudos têm focado em alternativas menos invasivas e mais precisas na abordagem de fluidos em pacientes com LPA/SDRA. Nesse contexto, recentes estudos têm demonstrado a superioridade de parâmetros dinâmicos sobre parâmetros estáticos na responsividade de fluidos. Além disso, parâmetros que forneçam informações importantes de pré-carga cardíaca e do grau de edema pulmonar têm sido enfatizados por alguns ensaios clínicos de pequeno porte.Indica-se a restrição de fluidos em pacientes com LPA/SDRA desde que não haja choque circulatório. Nessa situação, considera-se o uso de parâmetros dinâmicos para determinar a quantidade e o tipo de fluido administrados. Para a determinação de edema pulmonar, lança-se mão da medida da água extravascular pulmonar, sabendo de suas potencialidades e limitações.

The morbidity and mortality remain elevated in patients with acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Hemodynamic stabilization in such patients may require fluid resuscitation, but the increase in hydrostatic pressure may worsen lung edema in presence of increased permeability of the alveolar-capillary membrane. Therefore, accurate evaluation of the fluid state and prediction of the hemodynamic response are essential. Recent studies have focused on the induction of a negative fluid balance in ALI patients who are not in circulatory shock. Other studies of ALI/ARDS patients have focused on fluid management strategies that are less invasive and more accurate. In this context, recent studies have demonstrated the superiority of dynamic parameters over static parameters in determining the hemodynamic response. In addition, parameters that furnish useful data regarding cardiac preload and the degree of pulmonary edema have been emphasized in recent small clinical trials. In ALI/ARDS patients, fluid restriction is indicated if there are no clinical signs of circulatory shock. In such cases, the nature and quantity of fluid administered should be determined on the basis of the dynamic parameters. To screen for pulmonary edema, extravascular lung water can be measured, assuming that its potential and limitations are borne in mind.