体外膜肺氧合治疗ARDS的实验研究

目的：探讨体外膜肺氧合（ECMO）治疗ARDS的有效性和可行性。方法：采用油酸注入法制备犬ARDS模型,将15只犬随机分为3组：对照组（n=5）、模型组（n=5）及V-VECMO治疗组,通过监测血气指标、血流动力学指标、血管外肺水含量及肺顺应性指标,评价V-VECMO疗效。结果：V-VECMO明显提高了动脉和混合静脉血氧分压,增加氧供,增加心排血量,降低肺血管阻力,减轻肺水肿,肺功能明显改善。结论：ECMO治疗ARDS有效和可行,为临床治疗ARDS提供了新思路。     

Extracorporeal Membrane Oxygenation Used in Acute Respiratory Distress Syndrome with COVID-19: A Systematic Review and Meta-Analysis

IntroductionProtective pulmonary mechanical ventilation, higher positive end-expiratory pressure, neuromuscular blockade, prone positioning, and pulmonary recruitment procedures are all strategies in severe COVID-19 cases. Extracorporeal Membrane Oxygenation (ECMO) can be seen as an alternative to traditional treatment in certain patients when conventional therapy fails. We present a study that intends to systematically review and meta-analysis ECMO use in COVID-19 patients.MethodsWe search major medical databases (Cochrane Library, PubMed, EMBASE, MedRxiv) for clinical trials that were released between January 2020 until February 2021, had full-text availability, were written in English, and humans studies.We used National Heart, Lung, and Blood Institute (NHLBI) quality evaluation methods for retrospective cohort and cross-sectional studies to evaluate the quality of the articles. In addition, we used the Mantel–Haenszel random-effects meta-analysis of using RevMan 5.4.ResultsA total of 33 studies involving 3090 patients were included in the systematic review and six studies in the meta-analysis. There were 828 patients admitted to the ICU, of which 779 patients had ARDS (94%). Of the total study, 527 patients received ECMO therapy (17%). ARDS incidence was associated with complications during ICU care compared to non-ICU care (OR 107.98; 95% CI 55.51–210.03; p < 0.00001). Indirect comparisons, the incidence of mortality was associated with ECMO compared with non-ECMO (OR 15.79; 95% CI 4.21–59.28; p < 0.0001).ConclusionThe incidence of ARDS was associated with complications during ICU stay, and the incidence of mortality was associated with ECMO. Further study about mechanisms involving illness and death of patients from COVID-19 is needed.     

Venovenous Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome in Adults: Prognostic Factors for Outcomes

Despite a therapeutic option for severe acute respiratory distress syndrome (ARDS), the survival benefit of venovenous extracorporeal membrane oxygenation (VV-ECMO) is still controversial in adults. This study was aimed at investigating the prognostic factors for ECMO-treated ARDS in adult patients.From 2012 to 2015, 49 patients (median age: 57 years) received VV-ECMO in our institution and were included in this retrospective study. The indication of VV-ECMO was a severe hypoxemia (P_aO₂/FiO₂ ratio <70 mmHg) under mechanical ventilation (MV) with a peak inspiratory pressure (PIP) >35 cmH₂O and a F_iO₂ >0.8. To decrease the impact of pulmonary injuries associated with the high-pressure ventilation, the settings of MV on VV-ECMO were downgraded according to our protocol. Outcomes of this study were death on VV-ECMO and death in hospital. Important demographic and clinical data during the treatment were collected for outcome analyses.All patients experienced significant improvements in arterial oxygenation on VV-ECMO. Twenty-four hours after initiation of VV-ECMO, the median P_aO₂/FiO₂ ratio increased from 58 to 172 mmHg (P < 0.001) and the median S_aO₂ increased from 86% to 97% (P < 0.001). In the meantime, the MV settings were also effectively downgraded. The median PIP decreased from 35 to 29 cmH₂O (P < 0.001) and the median tidal volume decreased from 7 to 5 ml/kg/min (P < 0.001). Twelve patients died during the treatment of VV-ECMO and 21 patients died before hospital discharge. Among all of the pre-ECMO variables, the pre-ECMO pulmonary dynamic compliance (PC_dyn) <20 mL/cmH₂O was identified to be the prognostic factor of death on VV-ECMO (odds ratio [OR]: 6, 95% confidence interval [CI]: 1–35, P = 0.03), and the pre-ECMO duration of MV >90 hours was the prognostic factor of death before hospital discharge (OR: 7, 95% CI: 1–29, P = 0.01).VV-ECMO was a useful salvage therapy for severe ARDS in adults. However, the value of PC_dyn and the duration of MV before intervention with VV-ECMO may significantly affect the patients’ outcomes.     

Adenovirus Pneumonia Complicated With Acute Respiratory Distress Syndrome: A Case Report

Severe adenovirus infection in children can manifest with acute respiratory distress syndrome (ARDS) and respiratory failure, leading to the need for prolonged mechanical support in the form of either mechanical ventilation or extracorporeal life support. Early extracorporeal membrane oxygenation (ECMO) intervention for children with ARDS should be considered if selection criteria fulfill.We report on a 9-month-old boy who had adenovirus pneumonia with rapid progression to ARDS. Real-time polymerase chain reaction tests of sputum and pleural effusion samples confirmed adenovirus serotype 7. Chest x-rays showed progressively increasing infiltrations and pleural effusions in both lung fields within 11 days. Because conventional ARDS therapies failed, we initiated ECMO with high-frequency oscillatory ventilation (HFOV) for 9 days. Chest x-rays showed gradual improvements in lung expansion.This patient was subsequently discharged after a hospital stay of 38 days. Post-ECMO and adenovirus sequelae were followed in our outpatient department.Adenovirus pneumonia in children can manifest with severe pulmonary morbidity and respiratory failure. The unique lung recruitment by HFOV can be a useful therapeutic option for severe ARDS patients when combined with sufficient lung rest provided by ECMO.     

Use of Extracorporeal Membrane Oxygenation to Rescue Patients With Refractory Ventricular Arrhythmia in Acute Myocardial Infarction

Refractory ventricular arrhythmia is a serious problem in acute myocardial infarction (AMI), with an extremely high mortality rate and limited effective treatment. Extracorporeal membrane oxygenation (ECMO) is useful to rescue patients with cardiopulmonary collapse. However, little is known about whether ECMO is a potential rescue technique for patients with refractory ventricular arrhythmia in AMI.We retrospectively analyzed prospectively collected data on patients with AMI and refractory ventricular arrhythmia who underwent ECMO as rescue therapy and the bridge to revascularization from February 2001 to January 2013. Primary endpoint was mortality on index admission, and secondary endpoint was mortality on index admission or advanced brain damage at discharge.A total of 69 (62 men) patients were enrolled in this study. During the index admission, 39 patients (56.5%) met primary endpoint, and 45 patients (65.2%) met secondary endpoint, respectively. In multivariate Cox regression analysis, both the presence of profound anoxic encephalopathy and acute renal failure requiring dialysis were significant predictive factors for both primary and secondary endpoints.ECMO is a feasible rescue therapy and bridge to revascularization in patients with refractory ventricular arrhythmia in acute myocardial infarction. The presence of profound anoxic encephalopathy and acute renal failure requiring dialysis were significant prognostic factors.     

Successful Use of Intravenous B-blocker Therapy in Cardiogenic Shock Supported With Venoarterial Extracorporeal Membrane Oxygenation: A Case Series

Tachycardia in cardiogenic shock (CS) might reduce the cardiac output (CO) by decreasing the ventricular filling time. Nevertheless, heart rate (HR) control with agents that possess negative inotropy might decrease the CO. Therefore, controlling the tachycardia in the setting of CS remains controversial. We herein describe four cases of patients presenting with myocardial infarction complicated with CS that required rescue venoarterial extracorporeal membrane oxygenation (VA-ECMO) initiation. Tachycardia was present with HR ～130-140 beats per minute after VA-ECMO initiation, and hence esmolol was infused continuously at a starting dose of 10-20 mcg/kg/min and titrated according to HR. With the use of esmolol to control the HR in the setting of CS supported with VA-ECMO, lactate cleared, and echocardiographic parameters improved, allowing the four cases to be successfully decannulated from ECMO. Our report indicates that short-acting beta-blocker could be safely used in the complex scenario of severe tachycardia while supported with VA-ECMO.     

Successful Use of Veno-Venous Extracorporeal Membrane Oxygenation in an Adult Patient with Sickle Cell Anemia and Severe Acute Chest Syndrome

A 25-year-old female with sickle cell anemia presented with respiratory failure due to acute chest syndrome (ACS). Given her severely compromised cardiopulmonary status, she was started on veno-venous extracorporeal membrane oxygenation (VV-ECMO). After 20 days, the patient’s respiratory status improved and she was successfully decannulated. Veno-venous extracorporeal membrane oxygenation can be utilized for severe ACS in adult patients with sickle cell disease. Prompt initiation of this modality may improve outcomes in adult patients with sickle cell disease complicated by life threatening ACS.     

Tracheobronchial Obstruction Due to Blood Clots in Acute Pulmonary Embolism with Cardiac Arrest Managed with Extracorporeal Membrane Oxygenation

A 66-year-old Japanese woman developed pulseless electrical activity following an acute pulmonary embolism and was treated with thrombolytic therapy. She remained hemodynamically unstable and therefore underwent extracorporeal membrane oxygenation (ECMO). While receiving treatment with ECMO, blood clots induced by endobronchial hemorrhage caused tracheobronchial airway obstruction, leading to ventilatory defect. Furthermore, her cardiac function improved, resulting in cerebral hypoxemia progression. Therefore, the blood clots were removed with a Fogarty balloon catheter and endobronchial urokinase administration, resulting in improvement in her respiratory condition. Finally, ECMO was decannulated, and the patient was discharged from our hospital without difficulties in her activities of daily living.     

Case Fatality of Hospitalized Patients with COVID-19 Infection Suffering from Acute Respiratory Distress Syndrome in Germany

Aims: Patients suffering from viral pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are at risk of developing acute respiratory distress syndrome (ARDS). ARDS is a serious complication of COVID-19 that requires early recognition and comprehensive management. Little is known about the concomitant prevalence of both entities in Germany. Thus, we sought to analyze predictors and regional trends of case fatality in patients with COVID-19 and ARDS in Germany. Methods: We analyzed data on the characteristics, comorbidities and in-hospital outcomes for all hospitalized patients with COVID-19 and compared those with and without ARDS in Germany in 2020. Results: Overall, 176,137 hospitalized patients with confirmed COVID-19 were included in this analysis; among these, 11,594 (6.6%) suffered from ARDS. Most patients with ARDS were treated in hospitals in urban areas (n = 6485); proportion rate of mechanical ventilation was higher (45.9%) compared to those treated in hospitals of suburban (36.1%) or rural areas (32.0%). Proportion of ARDS grew exponentially with age until the sixth decade of life. Case-fatality rate was considerably higher in COVID-19 patients with ARDS compared to those without (48.3% vs. 15.8%; p < 0.001). Independent predictors of in-hospital case fatality with an OR > 3 were age ≥ 70 years, severe ARDS, severe liver disease, acute renal failure, stroke, dialysis treatment, shock and necessity of ECMO. Conclusions: The case fatality of COVID-19 patients with ARDS is dramatically high and shows relevant regional disparities. Our findings may help to draw more attention to predictors for in-hospital case fatality in patients hospitalized with COVID-19 and suffering from ARDS.     

Pheochromocytoma Crisis With Severe Cyclic Blood Pressure Fluctuations in a Cardiac Pheochromocytoma Patient Successfully Resuscitated by Extracorporeal Membrane Oxygenation: A Case Report

Cardiac pheochromocytoma is relatively rare. Few reports describe the intraoperative and postoperative progression of patients experiencing a life-threatening pheochromocytoma crisis treated with extracorporeal membrane oxygenation (ECMO).A 35-year-old man was referred to our facility for paroxysmal hypertension with a 10-year history of sweating, headaches, cardiac palpitations, and postexercise dyspnea. The patient initially underwent urine catecholamine measurement and an isotope scan, somatostatin receptor scintigraphy, and 18F-fluorodeoxyglucose positron emission tomography/computer tomography (CT), which indicated a multiple, cardiac pheochromocytoma. Echocardiography, cardiac magnetic resonance imaging (MRI), CT reconstruction, and a coronary CT angiography revealed several lesions at the aortic root and along the cardiac vasculature.Multifocal cardiac pheochromocytoma was diagnosed and pheochromocytoma crisis with severe cyclic blood pressure fluctuation occurred during surgery.Surgical resection of multiple pheochromocytomas in the right medial carotid sheath, mediastinum between the main and pulmonary arteries, and between the abdominal aorta and inferior vena artery was performed. To ensure cardiac perfusion and avoid severe circulatory fluctuation, the cardiac paraganglioma resection was prioritized. After resecting the cardiac pheochromocytoma, a severe pheochromocytoma crisis with rapid cyclic blood pressure fluctuation developed. ECMO and intraaortic balloon pump (IABP) were initiated to stabilize circulation and perfusion. Phenoxybenzamine, norepinephrine, epinephrine, and fluid resuscitation were administered to support cardiovascular function.The magnitude of blood pressure fluctuation steadily decreased with treatment. IABP was discontinued after 3 days, and ECMO was discontinued after 16 days. The patient was discharged 3 months postoperatively.This case indicates that mechanical life support with ECMO is a valuable option for pheochromocytoma-induced cardiac shock and should be considered as an effective therapeutic choice in patients with highly unstable hemodynamic function.     

Incidence and Outcomes of Acute Respiratory Distress Syndrome: A Nationwide Registry-Based Study in Taiwan, 1997 to 2011

Most epidemiological studies of acute respiratory distress syndrome (ARDS) have been conducted in western countries, and studies in Asia are limited. The aim of our study was to evaluate the incidence, in-hospital mortality, and 1-year mortality of ARDS in Taiwan.We conducted a nationwide inpatient cohort study based on the Taiwan National Health Insurance Research Database between 1997 and 2011. A total of 40,876 ARDS patients (68% male; mean age 66 years) were identified by International Classification of Diseases, 9th edition coding and further analyzed for clinical characteristics, medical costs, and mortality.The overall crude incidence of ARDS was 15.74 per 100,000 person-years, and increased from 2.53 to 19.26 per 100,000 person-years during the study period. The age-adjusted incidence of ARDS was 15.19 per 100,000 person-years. The overall in-hospital mortality was 57.8%. In-hospital mortality decreased from 59.7% in 1997 to 47.5% in 2011 (P < 0.001). The in-hospital mortality rate was lowest (33.5%) in the youngest patients (age 18–29 years) and highest (68.2%) in the oldest patients (>80 years, P < 0.001). The overall 1-year mortality rate was 72.1%, and decreased from 75.8% to 54.7% during the study period. Patients who died during hospitalization were older (69 ± 17 versus 62 ± 19, P < 0.001) and predominantly male (69.8% versus 65.3%, P < 0.001). In addition, patients who died during hospitalization had significantly higher medical costs (6421 versus 5825 US Dollars, P < 0.001) and shorter lengths of stay (13 versus 19 days, P < 0.001) than patients who survived.We provide the first large-scale epidemiological analysis of ARDS incidence and outcomes in Asia. Although the overall incidence was lower than has been reported in a prospective US study, this may reflect underdiagnosis by International Classification of Diseases, 9th edition code and identification of only patients with more severe ARDS in this analysis. Overall, there has been a decreasing trend in in-hospital and 1-year mortality rates in recent years, likely because of the implementation of lung-protective ventilation.