Survival Predictors for Severe ARDS Patients Treated with Extracorporeal Membrane Oxygenation: A Retrospective Study in China

Predictors for Successful Weaning from Veno-Venous Extracorporeal Membrane Oxygenation in Patients with Severe Acute Respiratory Distress Syndrome

Purpose

This study aimed to investigate the predictors of successful weaning from veno-venous extracorporeal membrane oxygenation (VV-ECMO) among patients with severe acute respiratory distress syndrome (ARDS) in our centre.

Methods

The clinical data of patients with severe ARDS who were treated with VV-ECMO between January 2019 and January 2022 were retrospectively analysed. Due to the outcomes of weaning from extracorporeal membrane oxygenation (ECMO), the considered patients with ARDS were divided into a successful weaning group and an unsuccessful weaning group. Logistic regression analysis was employed to evaluate predictors for successful VV-ECMO weaning among patients with severe ARDS.

Results

A total of 65 patients with severe ARDS were included for analysis. Among them, 31 (47.69%) patients were grouped into the successful weaning group, while 34 (52.30%) patients were grouped into the unsuccessful weaning group. Univariate analysis showed that Age (odds ratio [OR] =0.939; 95% confidence interval [CI] =0.896-0.983; p = 0.008), APACHEII scores before ECMO (OR =0.651; 95% CI =0.537-0.789; p < 0.001), Renal insufficiency (OR =0.061; 95% CI =0.012 -0.298; p = 0.001), MAP before ECMO (OR =1.246; 95% CI =1.114-1.392; p<0.001), PaO2 during ECMO (OR =1.083; 95% CI =1.033-1.135; p = 0.001), and CRRT (OR =0.080; 95% CI =0.022-0.285; p = 0.008) were identified as an independent predictor of successful VV-ECMO weaning. After multivariate analysis was performed, APACHE II scores before ECMO (OR = 0.651; 95% CI = 0.462-0.919; p = 0.015) were identified as independent predictors for successful VV-ECMO weaning.

Conclusion

In conclusion, in severe ARDS patients, lower APACHE II scores predicted successful wean from VV-ECMO.

Secondary pneumomediastinum in COVID-19 patient: A case managed with VV-ECMO

Air leak syndrome, including pneumomediastinum (PM), pneumopericardium, pneumothorax, or subcutaneous emphysema, is primarily caused by chest trauma, cardiothoracic surgery, esophageal perforation, and mechanical ventilation. Secondary pneumomediastinum (SP) is a rare complication, with a much lower incidence reported in patients with coronavirus disease 2019 (COVID-19). Our patient was a 44-year-old nonsmoker male with a previous history of obesity (Body Mass Index [BMI] 35 kg/m2), hyperthyroidism, hypokinetic cardiopathy and atrial fibrillation in treatment with flecainide, who presented to the emergency department with 6 days of fever, cough, dyspnea, and respiratory distress. The COVID-19 diagnosis was confirmed based on a polymerase chain reaction (PCR) test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). After initiation of mechanical ventilation, a chest computed tomography (CT) on the first day revealed bilateral multifocal ground-glass opacities, consolidation and an extensive SP and pneumoperitoneum. Our therapeutic strategy was initiation of veno-venous extracorporeal membrane oxygenation (VV-ECMO) as a bridge to recovery after positioning 2 drains (mediastinal and pleural), for both oxygenation and carbon dioxide clearance, to allow protective and ultra-protective ventilation to limit ventilator-induced lung injury (VILI) and the intensity of mechanical power for lung recovery. After another chest CT scan which showed a clear reduction of the PM, 2 pronation and neuromuscular relaxation cycles were also required, with improvement of gas exchange and respiratory mechanics. On the 15th day, lung function recovered and the patient was then weaned from VV-ECMO, and ultimately made a good recovery and was discharged. In conclusion, SP may be a reflection of extensive alveolar damage and should be considered as a potential predictive factor for adverse outcome in critically ill SARS-CoV2 patients.

Predictors of mortality in trauma patients with acute respiratory distress syndrome receiving extracorporeal membrane oxygenation

Objective

Trauma-related Acute Respiratory Distress Syndrome (TR-ARDS) mortality ranges from 30 to 80%. Extracorporeal membrane oxygenation (ECMO) has demonstrated a survival benefit in select cases of TR-ARDS. In order to provide improved patient selection, we evaluated predictors of mortality in TR-ARDS patients receiving ECMO, hypothesizing age and severe thoracic trauma as risk factors for mortality.

Methods

The Trauma Quality Improvement Program (2010-2016) was queried for patients ≥ 18-years-old with TR-ARDS receiving ECMO. Survivors were compared to those who died. A multivariable logistic regression model was used for analysis and included covariates known to increase risk of mortality in trauma patients.

Results

From 362 TR-ARDS patients on ECMO, 226 (62.4%) survived and 136 (37.6%) died. Those who died were older (median, 28 vs. 24-years-old, p = 0.036) and had a higher injury severity score (29 vs. 26, p = 0.040) than survivors. After adjusting for covariates, independent predictors of mortality included a severe head (OR=2.66, CI=1.29-5.49, p = 0.008) and thorax (OR =3.52, CI=1.96-6.33, p < 0.001) injury. Age ≥ 65-years-old was not a predictor of mortality (p = 0.432).

Discussion

Age ≥ 65 years did not appear to increase the risk of mortality in patients with TR-ARDS receiving ECMO. However, those with severe head or thorax injury had more than a two-fold and three-fold increased risk of death, respectively. TR-ARDS patients differ from medical ARDS patients in terms of etiology, age and injuries. Thus, prior pre-ECMO mortality prediction models may lack predictive capability for trauma patients. Future prospective studies are needed to confirm our findings and develop guidelines for utilization of ECMO for trauma patients.

Trend of extracorporeal membrane oxygenation support in patients with acute respiratory distress syndrome in South Korea

We examined and compared the clinical characteristics of acute respiratory distress syndrome (ARDS) patients who received and did not receive extracorporeal membrane oxygenation (ECMO) support. The national health insurance database of South Korea was used to obtain real-world data. All adult patients admitted to intensive care units for ARDS treatment between 1 January 2014 and 31 December 2019 were included in this study. Of the 10,173 patients with ARDS included in the analysis, 740 (7.3%) received ECMO support for a mean duration of 1.6 days (standard deviation [SD]: 2.8 days) and were assigned to the ECMO group. The ECMO group had a significantly lower mean age at 57.0 years (SD: 15.7 years) than the non-ECMO group (71.8 Â years [SD: 15.1 Â years], P < 0.001). In multivariable logistic regression, a 1-year increase in age was associated with a 5% lower prevalence of ECMO support. The annual case volume was classified into four groups by quartile ratio (Q1 [lowest], Q2, Q3, and Q4 [highest]), and Q2, Q3, and Q4 groups showed a higher prevalence of ECMO support than the Q1 group. ECMO support was also performed more frequently in high case volume centers than in low case volume centers for ARDS patients.

Successful lung-protective ventilatory management during the VV-ECMO in a severe COVID-19 pneumonia patient with extensive pneumomediastinum and subcutaneous emphysema: a case report

Background

Ventilatory management of respiratory failure with pneumomediastinum/subcutaneous emphysema is not established. Herein, we report a case of severe COVID-19 pneumonia with extensive pneumomediastinum/subcutaneous emphysema, rescued by thorough lung-protective ventilatory management after applying the VV-ECMO.

Case presentation

A 68-year-old male with no medical history was admitted to a local hospital and diagnosed with COVID-19 pneumonia. His pulmonary parameters worsened during invasive ventilation due to the development of pneumomediastinum/subcutaneous emphysema, and then he was transferred to our hospital. On arrival, we immediately decided to apply VV-ECMO and switch to ultraprotective ventilation. After maintaining the initial ventilation with a neuromuscular blocking agent for 2 days, we gradually increased PEEP while limiting PIP to 25 cmH₂O. The patient was weaned off VV-ECMO on day 10; he was transferred to the medical ward after extubation.

Conclusions

Lung-protective ventilatory management should be performed thoroughly during VV-ECMO in severe COVID-19 pneumonia with pneumomediastinum/subcutaneous emphysema.

Nosocomial Infections During Extracorporeal Membrane Oxygenation in Pediatric Patients: A Multicenter Retrospective Study

OBJECTIVE

Extracorporeal membrane oxygenation (ECMO) is increasingly used in critically ill patients with respiratory and/or cardiac failure. This study aimed to investigate the epidemiology and risk factors of nosocomial infection (NI) in pediatric patients who underwent ECMO for respiratory and/or circulatory failure.

METHODS

Medical records for patients that were administered underwent ECMO support at Xiangya Second Hospital of Central South University, The Sixth Medical Center of PLA General Hospital, and Children's Hospital Affiliation of Zhengzhou University, from September 2012 to December 2019 were retrospectively reviewed. Clinical data of the patients who developed NI were collected and analyzed. Univariate and multivariate logistic regressions were performed to identify the independent predictive factors of NI during ECMO.

RESULTS

A total of 54 first episodes of NI were identified in the 190 patients on ECMO, including 32 cases of respiratory tract infections, 20 cases of bloodstream infections, and 2 cases of surgical site wound infections. Gram-negative pathogens were the dominant pathogens isolated, accounting for 92.6% of the NI. The incidence of ECMO-related NI was 47.6 cases per 1,000 ECMO days. In the univariate logistic regression, ECMO mode, ECMO duration, ICU duration, and peritoneal dialysis were associated with the development of NI in patients with ECMO support. However, in the multivariate analysis, only ECMO duration (OR = 2.46, 95%CI: 1.10, 5.51; P = 0.029), ICU duration (OR = 1.35, 95%CI: 1.05, 1.59; P = 0.017) and peritoneal dialysis (OR = 2.69, 95%CI: 1.08, 5.73; P = 0.031) were the independent predictive factors for NI during ECMO support.

CONCLUSION

This study identified the significant correlation between ECMO-related NI and ECMO duration, ICU duration, and peritoneal dialysis. Appropriate preventive measures are needed for hospitals to reduce the incidence of ECMO in pediatric patients.

Practice Patterns and Outcome of Extracorporeal Membrane Oxygenation Therapy for Severe Acute Respiratory Distress Syndrome in Indian ICUs

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is increasingly used in managing patients with severe acute respiratory distress syndrome (ARDS). The aim of the study is to describe the practice of ECMO and evaluate the outcomes in patients with severe ARDS in Indian intensive care units (ICUs).

METHODS

Data of 39 patients with severe ARDS managed with ECMO in two tertiary centers between 2012 and 2018 were retrospectively studied.

RESULTS

The mean age of the patient was 44.6 ± 13.5 years and 51% were female. Primary ARDS due to viral pneumonia was the common indication for ECMO. Mean APACHE II and Murray scores were 32.3 ± 7.8 and 3.64 ± 0.21, respectively. Prone ventilation and/or inhaled nitric oxide were used in 69.3% of the patients prior to ECMO therapy. Among 39 patients, 38 patients were managed with venovenous ECMO and 1 patient was managed with venoarterial ECMO. Average ECMO duration was 9.4 ± 6.9 days. Among the 17 (43.5%) patients successfully weaned off ECMO, 15 (38.5%) survived to discharge home. The average ICU and hospital length of stay were 18.9 ± 15.5 and 20.6 ± 16.6 days, respectively. While, sepsis was the common complication noted in 19 (49%) patients, bleeding and thrombotic complications were also noted in six and two patients, respectively.

CONCLUSION

In conclusion, ECMO support was used as rescue therapy in severe ARDS with a survival rate of 39%. Sepsis was the common complication of ECMO followed by bleeding and thrombosis.

HOW TO CITE THIS ARTICLE

Mariappan R, Kumar M, Ramakrishnan N, Mani AK, Kumar S, Chandrasekaran V. Practice Patterns and Outcome of Extracorporeal Membrane Oxygenation Therapy for Severe Acute Respiratory Distress Syndrome in Indian ICUs. Indian J Crit Care Med 2021;25(11):1263-1268.

Factors associated with intraoperative extracorporeal membrane oxygenation support during lung transplantation

BACKGROUND

Intraoperative Extracorporeal membrane oxygenation (ECMO) is increasingly being applied as life-support for lung transplantation patients. However, factors associated with this procedure in lung transplantation patients have not yet been characterized. The aim of this study was to identify preoperative factors of intraoperative ECMO support during lung transplantation and to evaluated the outcome of lung transplantation patients supported with ECMO.

METHODS

Patients underwent lung transplantation treated with and without ECMO in Guangzhou Institute of Respiratory Diseases between January 2015 to August 2018 were retrospectively reviewed. Patient demographics and clinical variables were collected and analyzed. Multivariate logistic regression was performed to identify factors independently associated with intraoperative extracorporeal membrane oxygenation support during lung transplantation.

RESULTS

During the study period, 138 patients underwent lung transplantation at our institution, the mean LAS was (56.63 ± 18.39) (range, 32.79 to 88.70). Fourty four patients were treated with veno-venous/veno-arterial ECMO. Among the patients, 32 patients wean successfully ECMO after operation, 12 patients remain ECMO after operation, and 32 patients (62.74%) survived to hospital discharge. In multiple analysis, the following factors were associated with intraoperative ECMO support: advanced age, high PAP before operation, duration of mechanical ventilation before operation, a higher APACHE II and primary diagnosis for transplantation. The overall survival rates at 1, 3, and 12 months were 90.91, 72.73, and 56.81% in the ECMO group, and 95.40, 82.76, and 73.56% in the non-ECMO group, respectively (log-rank P = 0.081). Patients who underwent single lung transplant had a lower survival rates in ECMO group as compared with non-ECMO group at 1, 3, and 12 months (90.47% vs 98.25, 71.43% vs 84.21, and 52.38% vs 75.44%) (log-rank P = 0.048).

CONCLUSIONS

The preoperative factors of intraoperative ECMO support during lung transplantation included age, high PAP before operation, preoperative mechanical ventilation, a higher APACHE II and primary diagnosis for transplantation based on multivariate analysis.

Extracorporeal Life Support in Adult Patients: A Global Perspective of the Last Decade

Extracorporeal life support (ECLS) is an external medical device to treat critically ill patients with cardiovascular and respiratory failure. In a nutshell, ECLS is only a "bridging" mechanism that provides life support while the heart and/or the lungs is recovering either by therapeutic medical interventions, transplantation, or spontaneously. Extracorporeal life support has been developed since 1950s, and many studies were conducted to improve ECLS techniques, but unfortunately, the survival rate was not improved. Because of Dr Bartlett's success in using ECLS to treat neonates with severe respiratory distress in 1975, ECLS is made as a standard lifesaving therapy for neonates with severe respiratory distress. However, its use for adult patients remains debatable. The objectives of this study are to outline and provide a general overview of the use of ECLS especially for adult patients for the past 10 years and to elaborate on the challenges encountered by each stakeholder involved in ECLS. The data used for this study were extracted from the ELSO Registry Report of January 2018. Results of this study revealed that the number of ECLS centers and the use of ECLS are increasing over the year for the past decade. There was also a shift of the patient's age category from neonatal to adult patients. However, the survival rates for adult patients are relatively low especially for cardiac and extracorporeal cardiopulmonary resuscitation cases. To date, the complications are still the major challenge of ECLS. Other challenges encountered by the stakeholders in ECLS are the limited amount of well-trained and experienced ECLS teams and centers, the limited government expenditure on health, and the lack of improvement and development of ECLS techniques and devices. Further studies are needed to evaluate the value of ECLS for adult patients.

Clinical risk factors of extracorporeal membrane oxygenation support in older adults

Background

The ageing population and the expected increase in the number of elderly patients make an evidence-based assessment of Extracorporeal Membrane Oxygenation (ECMO) therapy in old patients progressively more important. Veno-arterial (VA) ECMO results for patient aged <65 years is well known. However, the risk profile and in-hospital prognosis of advanced age patients with ECMO still need more investigation. The aim of this study was to identify risk factors that predicted the outcomes for elderly patients who received VA-ECMO.

Methods

In this retrospective study, medical records for patients with ECMO aged 65 years and over were collected between 2009 and 2012 at a tertiary hospital.

Results

A total of 99 patients (mean age: 76.4±6.4 years) were included. The most common condition requiring VA-ECMO support was cardiogenic shock. Among survivors on VA-ECMO, 28 (28.3%) patients were successfully weaned from support. Thirteen (13.1%) patients were successfully discharged. We found that cardiogenic shock (OR = 3.158, P = 0.013), acute physiology and chronic health evaluation II (APACHE II) score (OR = 1.147, P<0.001), and simplified acute physiology score II (SAPS II) score (OR = 1.054, P = 0.001) were risk factors associated with survival on VA-ECMO. By using the areas under the receiver operating characteristic (AUC) curve, the APACHE II score and SAPS II score displayed acceptable discriminative power (AUC 0.722; 0.715, respectively).

Conclusion

Our findings indicate that the risk of mortality increases with cardiogenic shock, higher APACHE II score, and higher SAPS II score. These risk factors can be utilized as potential predictors to identify the potential candidates for ECMO support.

Effect of Anemia on Prognosis in Patients on Extracorporeal Membrane Oxygenation

Anemia is a component of the pathological triangle in cardiorenal anemia syndrome and is a risk factor for mortality in acute respiratory distress syndrome. This study assessed the predictive value of anemia for outcomes in critically ill patients receiving extracorporeal membrane oxygenation (ECMO) support. This retrospective study analyzed patients who received ECMO support at the cardiovascular surgery intensive care unit in the study institute between July 2003 and March 2012. Patient data, such as demographic information, etiologies of ECMO implementation, clinical parameters, and in-hospital and 6-month mortality rates, were statistically analyzed. The overall in-hospital mortality rate among the enrolled 295 patients was 55.6%. Multivariate logistical regression analysis indicated that age, albumin levels, sequential organ failure assessment (SOFA) score, and hemoglobin (Hb) level on ECMO day 1 exhibited independent prognostic significance for predicting in-hospital mortality rate. The SOFA score exhibited the highest areas under the receiver operating characteristic curve value (0.812 ± 0.025). The Hb level on ECMO day 1 exhibited satisfactory calibration and discriminatory power. The cumulative 6-month survival rates differed significantly between patients with Hb levels less than and more than 8.85 g/dL (30.6 vs. 54.0%, respectively, P < 0.001). This study indicated that old age, low albumin levels, low Hb levels, and higher SOFA scores on ECMO day 1 increased the risk of mortality. The Hb level is a readily measurable parameter and with good predictive power for critical patients on ECMO.

A novel risk score for severe ARDS patients undergoing ECMO after retrieval from peripheral hospitals

BACKGROUND

Extracorporeal Membrane Oxygenation in severe ARDS unresponsive to conventional protective ventilation is associated with elevated costs, resource and complications, and appropriate risk stratification of candidate patients could be useful to recognize those more likely to benefit from ECMO. We aimed to derive a new outcome prediction score for patients retrieved by our ECMO team from peripheral centers, including systematic echocardiographic evaluation before ECMO start.

METHODS

Sixty-nine consecutive patients with refractory ARDS requiring ECMO transferred from peripheral centers to our ICU (a tertiary ECMO referral center), from 1 October 2009 to 31 December 2015, were assessed.

RESULTS

All patients were transported on ECMO (distance, median 77, range 4-456 km) The mortality rate was 41% (28/69). Our new risk score included age ≥ 42 years, BMI < 31 kg/m² , RV dilatation, and pH < 7.35. The proposed cut off (Youden's index method) of nine had a sensitivity of 96% and a specificity of 30% (AUC-ROC: 0.85, 95% CI: 0.76-0.94, P < 0.001). When assessing the discriminatory ability of our risk score in the population of local patients, survivors had a mean value of 15.4 ± 8.6, whereas non-survivors showed a mean value of 20.1 ± 7.4 (P < 0.001).

CONCLUSIONS

Our new risk score shows good discriminatory ability both in patients retrieved from peripheral centers and in those implanted at our center. This score includes variables easily available at bedside, and, for the first time, a pathophysiologic element, RV dilatation.

Mechanical Ventilation during Extracorporeal Membrane Oxygenation in Patients with Acute Severe Respiratory Failure

Conventionally, a substantial number of patients with acute respiratory failure require mechanical ventilation (MV) to avert catastrophe of hypoxemia and hypercapnia. However, mechanical ventilation per se can cause lung injury, accelerating the disease progression. Extracorporeal membrane oxygenation (ECMO) provides an alternative to rescue patients with severe respiratory failure that conventional mechanical ventilation fails to maintain adequate gas exchange. The physiology behind ECMO and its interaction with MV were reviewed. Next, we discussed the timing of ECMO initiation based on the risks and benefits of ECMO. During the running of ECMO, the protective ventilation strategy can be employed without worrying about catastrophic hypoxemia and carbon dioxide retention. There is a large body of evidence showing that protective ventilation with low tidal volume, high positive end-expiratory pressure, and prone positioning can provide benefits on mortality outcome. More recently, there is an increasing popularity on the use of awake and spontaneous breathing for patients undergoing ECMO, which is thought to be beneficial in terms of rehabilitation.

Outcomes and survival prediction models for severe adult acute respiratory distress syndrome treated with extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) for severe acute respiratory distress syndrome (ARDS) has known a growing interest over the last decades with promising results during the 2009 A(H1N1) influenza epidemic. Targeting populations that can most benefit from this therapy is now of major importance.

Survival has steadily improved for a decade, reaching up to 65% at hospital discharge in the most recent cohorts. However, ECMO is still marred by frequent and significant complications such as bleeding and nosocomial infections. In addition, physiological and psychological symptoms are commonly described in long-term follow-up of ECMO-treated ARDS survivors. Because this therapy is costly and exposes patients to significant complications, seven prediction models have been developed recently to help clinicians identify patients most likely to survive once ECMO has been initiated and to facilitate appropriate comparison of risk-adjusted outcomes between centres and over time. Higher age, immunocompromised status, associated extra-pulmonary organ dysfunction, low respiratory compliance and non-influenzae diagnosis seem to be the main determinants of poorer outcome.