Extracorporeal life support is safe in trauma patients

Veno-arterial-venous extracorporal membrane oxygenation (V-AV ECMO) in a patient in ARDS and cardiac instability after severe polytrauma

The role of extracorporeal life support (ECLS) in critically ill trauma patients is underutilized, mainly due to concerns of anticoagulation. However, short-term ECLS in these patients can be safely performed with no or minimal systemic anticoagulation. Case series show favorable outcomes in trauma patients with veno-venous (V-V) and veno-arterial (V-A) ECMO, respectively, but there are only a few case reports of successful veno-arterio-venous (V-AV) ECMO in polytrauma patients. We report on a 63-year-old female admitted to our emergency department following a severe car accident who was successfully treated in a multidisciplinary approach, including bridging to damage control surgery and recovery with a V-AV ECMO.

The Effect of Extracorporeal Membrane Oxygenation in Patients With Multiple Orthopaedic Injuries

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) plays a vital role in providing life support for patients with reversible cardiac or respiratory failure. Given the high rate of complications and difficulties associated with caring for ECMO patients, the goal of this study was to compare outcomes of orthopaedic surgery in polytrauma patients who received ECMO with similar patients who have not. This will help elucidate the timing and type of fixation that should be considered in patients on ECMO.

METHODS

A retrospective cohort was collected from the electronic medical record of two level I trauma centers over an 8-year period (2015 to 2022) using Current Procedural Terminology codes. Patients were matched with a similar counterpart not requiring ECMO based on sex, age, American Society of Anesthesiologists score, body mass index, injury severity score, and fracture characteristics. Outcomes measured included length of stay, number of revisions, time to definitive fixation, infection, amputation, revision surgery to promote bone healing, implant failure, bleeding requiring return to the operating room, and mortality.

RESULTS

Thirty-two patients comprised our ECMO cohort with a patient-matched control group. The ECMO cohort had an increased length of stay (40 versus 17.5 days, P = 0.001), number of amputations (7 versus 0, P = 0.011), and mortality rate (19% versus 0%, P = 0.024). When comparing patients placed on ECMO before definitive fixation and after definitive fixation, the group placed on ECMO before definitive fixation had significantly longer time to definitive fixation than the group placed on ECMO after fixation (14 versus 2.0 days, P < 0.001).

CONCLUSION

ECMO is a lifesaving measure for trauma patients with cardiopulmonary issues but can complicate fracture care. Although it is not associated with an increase in revision surgery rates, ECMO was associated with prolonged hospital stay and delays in definitive fracture surgery when initiated before definitive fixation.

LEVEL OF EVIDENCE

III.

ECMO in adult patients with severe trauma: a systematic review and meta-analysis

BACKGROUND

Severe trauma can result in cardiorespiratory failure, and when conventional treatment is ineffective, extracorporeal membrane oxygenation (ECMO) can serve as an adjunctive therapy. However, the indications for ECMO in trauma cases are uncertain and clinical outcomes are variable. This study sought to describe the prognosis of adult trauma patients requiring ECMO, aiming to inform clinical decision-making and future research.

METHODS

A comprehensive search was conducted on Pubmed, Embase, Cochrane, and Scopus databases until March 13, 2023, encompassing relevant studies involving over 5 trauma patients (aged ≥ 16 years) requiring ECMO support. The primary outcome measure was survival until discharge, with secondary measures including length of stay in the ICU and hospital, ECMO duration, and complications during ECMO. Random-effects meta-analyses were conducted to analyze these outcomes. The study quality was assessed using the Joanna Briggs Institute checklist, while the certainty of evidence was evaluated using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.

RESULTS

The meta-analysis comprised 36 observational studies encompassing 1822 patients. The pooled survival rate was 65.9% (95% CI 61.3-70.5%). Specifically, studies focusing on traumatic brain injury (TBI) (16 studies, 383 patients) reported a survival rate of 66.1% (95% CI 55.4-76.2%), while studies non-TBI (15 studies, 262 patients) reported a survival rate of 68.1% (95% CI 56.9-78.5%). No significant difference was observed between these two survival comparisons (p = 0.623). Notably, studies utilizing venoarterial extracorporeal membrane oxygenation (VA ECMO) (15 studies, 39.0%, 95% CI 23.3-55.6%) demonstrated significantly lower survival rates than those using venovenous extracorporeal membrane oxygenation (VV ECMO) (23 studies, 72.3%, 95% CI 63.2-80.7%, p < 0.001). The graded assessment of evidence provided a high degree of certainty regarding the pooled survival.

CONCLUSIONS

ECMO is now considered beneficial for severely traumatized patients, improving prognosis and serving as a valuable tool in managing trauma-related severe cardiorespiratory failure, haemorrhagic shock, and cardiac arrest.

Pediatric surgical interventions on ECMO

Extra Corporeal Membrane Oxygenation (ECMO) has historically been reserved for refractory pulmonary and cardiac support in children and adult. Operative intervention on ECMO was traditionally contraindicated due to hemorrhagic complications exacerbated by critical illness and anticoagulation needs. With advancements in ECMO circuitry and anticoagulation strategies operative procedures during ECMO have become feasible with minimal hemorrhagic risks. Here we review anticoagulation and operative intervention considerations in the pediatric population during ECMO cannulation. Pediatric surgical interventions currently described in the literature while on ECMO support include thoracotomy/thoracoscopy, tracheostomy, laparotomy, and injury related procedures i.e. wound debridement. A patient should not be precluded from a surgical intervention while on ECMO, if the surgery is indicated.

Infections complicating extracorporeal membrane oxygenation in patients with traumatic injuries

INTRODUCTION

Extracorporeal Membrane Oxygenation (ECMO) has increasing utility in adult patients with traumatic injuries. There is currently limited data on the pathogens complicating a trauma patient's ECMO course, making empiric antibiotic decisions difficult. This study aims to characterize the types of infection among patients with traumatic injuries on ECMO.

METHODS

A chart review was performed on all trauma patients at Brooke Army Medical Center receiving ECMO between February 2013 and July 2021. Charts were reviewed to identify pathogens by culture site as well as time to infection following cannulation.

RESULTS

Twenty-one trauma patients underwent ECMO during the study period. The majority of patients were men (90%) with a median age of 30 [IQR 27-38], and a median ECMO course of 9.8 days [IQR 3.9-14.1]. Motor vehicle crashes (81%) accounted for the majority of mechanisms of injury. Of the 24 infections, the majority were respiratory (n = 13, 58/1000 ECMO days) followed by skin and soft tissue (n = 6, 26/1000 ECMO days), blood stream (n = 4, 18/1000 ECMO days), and urinary tract (n = 1, 5/1000 ECMO days). Gram-negative bacteria were the most commonly isolated organism from all sites and at all time periods following cannulation. Multi-drug resistant organisms accounted for 35% (n = 9) of infections and were independent of time from cannulation.

DISCUSSION/CONCLUSION

This is the first study to describe infections in trauma patients requiring ECMO support. We observed majority Gram-negative infections regardless of culture site or time after cannulation. Thus, with infection in this population, empiric antibiotics should have broad spectrum coverage of Gram-negative organisms.

Outcome of post-traumatic acute respiratory distress syndrome in young patients requiring extracorporeal membrane oxygenation (ECMO)

We aimed to evaluate the outcomes of post-traumatic acute respiratory distress syndrome (ARDS) in young patients with and without Extracorporeal membrane oxygenation (ECMO) support. A retrospective analysis was conducted for trauma patients who developed ARDS at a level I trauma facility between 2014 and 2020. Data were analyzed and compared between ECMO and non-ECMO group. We identified 85 patients with ARDS (22 patients had ECMO support and 63 matched patients managed by the conventional mechanical ventilation; 1:3 matching ratio). The two groups were comparable for age, sex, injury severity score, abbreviated injury score, shock index, SOFA score, and head injury. Kaplan Meier survival analysis showed that the survival in the ECMO group was initially close to that of the non-ECMO, however, during follow-up, the survival rate was better in the ECMO group, but did not reach statistical significance (Log-rank, p = 0.43 and Tarone-Ware, p = 0.37). Multivariable logistic regression analysis showed that acute kidney injury (AKI) (Odds ratio 13.03; 95% CI 3.17–53.54) and brain edema (Odds ratio 4.80; 95% CI 1.10–21.03) were independent predictors of mortality. Sub-analysis showed that in patients with severe Murray Lung Injury (MLI) scores, non-ECMO group had higher mortality than the ECMO group (100% vs 36.8%, p = 0.004). Although ARDS is uncommon in young trauma patients, it has a high mortality. ECMO therapy was used in a quarter of ARDS cases. AKI and brain edema were the predictors of mortality among ARDS patients. ECMO use did not worsen the outcome in trauma patients; however, the survival was better in those who had severe MLI and ECMO support. Further prospective study is needed to define the appropriate selection criteria for the use of ECMO to optimize the outcomes in trauma patients.

Extracorporeal support for trauma: A trauma quality improvement project (TQIP) analysis in patients with acute respiratory distress syndrome

INTRODUCTION

The use of extracorporeal membrane oxygenation (ECMO) in trauma patients with severe acute respiratory distress syndrome (ARDS) continues to evolve. The objective of this study was to perform a comparative analysis of trauma patients with ARDS who received ECMO to a propensity matched cohort of patients who underwent conventional management.

METHODS

The Trauma Quality Improvement Program (TQIP) database was queried from 2013 to 2016 for all patients with ARDS and those who received ECMO. Demographics, as well as clinical, injury, intervention, and outcome data were collected and analyzed. Patients with ARDS were divided into two groups, those who received ECMO and those who did not. A propensity score analysis was performed using the following criteria: age, gender, vital signs (HR, SBP) and GCS on admission, Injury Severity Score (ISS), and Abbreviated Injury Scale (AIS) score in several body regions. Outcomes between the groups were subsequently compared using univariate as well as Cox regression analyses. Secondary outcomes such as hospitalization (HLOS), ICU length-of-stay (LOS) and ventilation days stratified for patient demographics, timing of ECMO and anticoagulation status were compared.

RESULTS

Over the 3-year study period, 8990 patients with ARDS were identified from the TQIP registry. Following exclusion, 3680 were included in the final analysis, of which 97 (2.6%) received ECMO. On univariate analysis following matching, patients who underwent ECMO had lower overall hospital mortality (23 vs 50%, p < 0.001) with higher rates of complications (p < 0.005), including longer HLOS. In those undergoing ECMO, early initiation (<7 days) was associated with shorter HLOS, ICU LOS, and fewer ventilator days. No difference was observed between the two groups with regard to anticoagulation.

CONCLUSION

Extracorporeal membrane oxygenation use in trauma patients with ARDS may be associated with improved survival, especially for young patients with thoracic injuries, early in the course of ARDS. Anticoagulation while on circuit was not associated with increased risk of hemorrhage or mortality, even in the setting of head injuries. The mortality benefit suggested with ECMO comes at the expense of a potential increase in complication rate and prolonged hospitalization.

Traumatic respiratory failure and veno-venous extracorporeal membrane oxygenation support

BACKGROUND

Respiratory failure (RF) is a common cause of death and morbid complication in trauma patients. Extracorporeal membrane oxygenation (ECMO) is increasingly used in adults with RF refractory to invasive mechanical ventilation. However, use of ECMO remains limited for this patient population as they often have contraindications for anticoagulation.

STUDY DESIGN

Medical records were retroactively searched for all adult patients who were admitted to the trauma service and received veno-venous ECMO (VV ECMO) support between June 2015 and August 2018. Survival to discharge and ECMO-related complications were collected and analyzed.

RESULTS

Fifteen patients from a large Level I trauma center met the criteria. The median PaO₂/FiO₂ ratio was 53.0 (IQR, 27.0-76.0), median injury severity score was 34.0 (IQR, 27.0-43.0), and the median duration of ECMO support was 11 days (IQR, 7.5-20.0). For this cohort, the survival-to-discharge rate was 87% (13/15). The incidence of neurologic complications was 13%, and deep vein thrombosis was reported in two cases (13%).

CONCLUSIONS

Survival rates of trauma patients in this study are equivalent to, or may exceed, those of non-trauma patients who receive ECMO support for other types of RF. With the employment of a multidisciplinary team assessment and proper patient selection, early cannulation, traumatic RF may be safely supported with VV ECMO in experienced centers.

Nursing Care for Extracorporeal Membrane Oxygenation in the Trauma Patient

Trauma patients that survive the immediate threat of death are at risk for potentially life-threatening complications such as acute respiratory distress syndrome and multisystem organ failure. Extracorporeal membrane oxygenation (ECMO) use in trauma patients has largely been controversial for concerns of inducing major hemorrhage with the use of systemic anticoagulation to prevent thrombus development while connected to the ECMO circuit. There is limited data available for specific guidelines for optimal management of the trauma population; however, recent studies suggest comparable outcomes to those of nontrauma patients treated with ECMO. The purpose of this case study was to introduce indications for implementation of ECMO in the trauma patient for pulmonary and hemodynamic compromise, describe the procedure of ECMO insertion, and delineate clinical expectations of the intensive care unit nurse within the multidisciplinary ECMO team. This case study presents a 28-year-old man who sustained a gunshot wound of the chest and was ultimately treated with ECMO for pulmonary compromise due to acute respiratory distress syndrome.

Characteristics and outcomes of extracorporeal life support in pediatric trauma patients

BACKGROUND

Extracorporeal life support utilizing extracorporeal membrane oxygenation (ECMO) techniques has been used in the pediatric population for numerous indications, but its use in trauma has been understudied. We sought to examine the indications, characteristics, and outcomes of children placed on ECMO for trauma and hypothesized that outcomes would be equivalent to those of patients placed on ECMO for other indications.

METHODS

We performed a retrospective review of all pediatric trauma patients in the Extracorporeal Life Support Organization registry from 1989 to 2018. Patient characteristics, indications for ECMO, pre- and post-ECMO ventilator settings and blood chemistry, complications, and survival rates were examined. Categories were stratified by mode: venovenous (VV), veno-arterial (VA), or conversion. Data were analyzed using SPSS software, with significance considered at p value less than 0.05.

RESULTS

We identified 573 patients with a median age of 4.82 years. The majority of patients (62.3%) were male and on VA support (54.5%). Drowning (38.7%) was the most common mechanism, followed by burns (21.1%) and thoracic trauma (17.8%). Complication rates were high (81.9%), with the most frequent types being cardiovascular, mechanical, and hemorrhagic. Incidences of complications (overall and by type) were similar to those reported in other Extracorporeal Life Support Organization cohorts. Overall survival was 55.3% and was significantly higher (p = 0.00) for patients on VV (74.3%) compared with those on VA (41.7%), even when controlling for mechanism.

CONCLUSION

Survival and complication rates of pediatric trauma patients on ECMO are comparable to those reported for other indications. Trauma should not be considered a contraindication for ECMO.

LEVEL OF EVIDENCE

Therapeutic, level V.

Severe Hypothermia and Frostbite Requiring ECMO and Four Limb Amputations

Severe hypothermia and frostbite can result in significant morbidity and mortality. We present a case of a patient with severe hypothermia and frostbite due to cold exposure after a snowmobile crash. He presented in cardiac arrest with a core temperature of 19°C requiring prolonged cardiopulmonary resuscitation, active internal rewarming, venoarterial extracorporeal membrane oxygenation, and subsequently amputations of all four extremities. Although severe hypothermia and frostbite can be a fatal condition, the quick action of Emergency Medical Services, emergency physicians, trauma surgeons, cardiothoracic surgeons, intensivists, and the burn team contributed to a successful recovery for this patient including a good neurological outcome. This case highlights the importance of a strong interdisciplinary team in treating this condition.

Intravascular treatment for ruptured facial artery aneurysm via percutaneous cardiopulmonary support device: A case report

Even in cases of cardiac arrest caused by hemorrhagic shock, when reliable control of the bleeding source is possible, ECPR may be an effective treatment option if anticoagulant therapy is well-managed and is withdrawn early.

Selective aortic arch perfusion with fresh whole blood or HBOC-201 reverses hemorrhage-induced traumatic cardiac arrest in a lethal model of noncompressible torso hemorrhage

BACKGROUND

Hemorrhage-induced traumatic cardiac arrest (HiTCA) has a dismal survival rate. Previous studies demonstrated selective aortic arch perfusion (SAAP) with fresh whole blood (FWB) improved the rate of return of spontaneous circulation (ROSC) after HiTCA, compared with resuscitative endovascular balloon occlusion of the aorta and cardiopulmonary resuscitation (CPR). Hemoglobin-based oxygen carriers, such as hemoglobin-based oxygen carrier (HBOC)-201, may alleviate the logistical constraints of using FWB in a prehospital setting. It is unknown whether SAAP with HBOC-201 is equivalent in efficacy to FWB, whether conversion from SAAP to extracorporeal life support (ECLS) is feasible, and whether physiologic derangement post-SAAP therapy is reversible.

METHODS

Twenty-six swine (79 ± 4 kg) were anesthetized and underwent HiTCA which was induced via liver injury and controlled hemorrhage. Following arrest, swine were randomly allocated to resuscitation using SAAP with FWB (n = 12) or HBOC-201 (n = 14). After SAAP was initiated, animals were monitored for a 20-minute prehospital period prior to a 40-minute damage control surgery and resuscitation phase, followed by 260 minutes of critical care. Primary outcomes included rate of ROSC, survival, conversion to ECLS, and correction of physiology.

RESULTS

Baseline physiologic measurements were similar between groups. ROSC was achieved in 100% of the FWB animals and 86% of the HBOC-201 animals (p = 0.483). Survival (t = 320 minutes) was 92% (11/12) in the FWB group and 67% (8/12) in the HBOC-201 group (p = 0.120). Conversion to ECLS was successful in 100% of both groups. Lactate peaked at 80 minutes in both groups, and significantly improved by the end of the experiment in the HBOC-201 group (p = 0.001) but not in the FWB group (p = 0.104). There was no significant difference in peak or end lactate between groups.

CONCLUSION

Selective aortic arch perfusion is effective in eliciting ROSC after HiTCA in a swine model, using either FWB or HBOC-201. Transition from SAAP to ECLS after definitive hemorrhage control is feasible, resulting in high overall survival and improvement in lactic acidosis over the study period.

Extracorporeal Membrane Oxygenation During Adult Noncardiac Surgery and Perioperative Emergencies: A Narrative Review

Over the last decade, the use of extracorporeal membrane oxygenation (ECMO) has increased significantly. In some centers, ECMO has been deployed to manage perioperative emergencies and plays a role in facilitating high-risk thoracic, airway, and trauma surgery, which may not be feasible without ECMO support. General anesthesiologists who usually manage these cases may not be familiar with the initiation and management of patients on ECMO. This review discusses the use of ECMO in the operating room for thoracic, airway, and trauma surgery, as well as obstetric and perioperative emergencies.

Heparin-free veno-venous extracorporeal membrane oxygenation in a multiple trauma patient: A case report

RATIONALE

Extracorporeal membrane oxygenation (ECMO) in multiple trauma patients with post-traumatic respiratory failure can be quite challenging because of the need for systemic anticoagulation, which may lead to excessive bleeding. In the last decade, there is a growing body of evidence that veno-venous ECMO (VV-ECMO) is lifesaving in multiple trauma patients with acute respiratory distress syndrome, thanks to technical improvements in ECMO devices.

PATIENT CONCERNS

We report a case of a 17-year-old multiple trauma patient who was drunken and had confused mentality.

DIAGNOSES

She was suffered from critical respiratory failure (life-threatening hypoxemia and severe hypercapnia/acidosis lasting for 70 minutes) accompanied by cardiac arrest and trauma-induced coagulopathy during general anesthesia.

INTERVENTIONS

We decided to start heparin-free VV-ECMO after cardiac arrest considering risk of hemorrhage.

OUTCOMES

She survived with no neurologic sequelae after immediate treatment with heparin-free VV-ECMO.

LESSONS

Heparin-free VV-ECMO can be used as a resuscitative therapy in multiple trauma patients with critical respiratory failure accompanied by coagulopathy. Even in cases in which life-threatening hypoxemia and severe hypercapnia/acidosis last for >1 hours during CPR for cardiac arrest, VV-ECMO could be considered a potential lifesaving treatment.

Use of ECMO support in pediatric patients with severe thoracic trauma

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has been used in the non-trauma setting for over 30 years. However, the use of ECMO in trauma remains a difficult question, as the risk of bleeding must be weighed against the benefits of cardiopulmonary support.

METHODS

Retrospective review of children who sustained severe thoracic trauma (chest abbreviated injury score ≥3) and required ECMO support between 2009 and 2016.

RESULTS

Of the 425 children who experienced severe thoracic trauma, 6 (1.4%) underwent ECMO support: 67% male, median age 4.8 years, median ISS 36, median GCS 3, and overall survival 83%. The median hospital day of ECMO initiation was 2 with a median ECMO duration of 7 days. All cannulations occurred through the right neck regardless of the size of the child. Five initially had veno-venous support with 1 requiring conversion to veno-arterial (VA) support. Both children on VA support suffered devastating cerebrovascular accidents, one of which ultimately led to withdrawal of care and death. Complications in the cohort included: paraplegia (1), neurocognitive defects/dysphonia (1), infected neck hematoma (1), deep femoral venous thrombosis (1), bilateral lower extremity spasticity (1).

CONCLUSION

This small cohort supports the use of ECMO in children with severe thoracic injuries as a potentially lifesaving intervention, however, not without significant complication.

LEVEL OF EVIDENCE

IV.

Extracorporeal life support in pediatric trauma: a systematic review

Introduction

Extracorporeal membrane oxygenation (ECMO) was once thought to be contraindicated in trauma patients, however ECMO is now used in adult patients with post-traumatic acute respiratory distress syndrome (ARDS) and multisystem trauma. Despite acceptance as a therapy for the severely injured adult, there is a paucity of evidence supporting ECMO use in pediatric trauma patients.

Methods

An electronic literature search of PubMed, MEDLINE, and the Cochrane Database of Collected Reviews from 1972 to 2018 was performed. Included studies reported on ECMO use after trauma in patients ≤18 years of age and reported outcome data. The Institute of Health Economics quality appraisal tool for case series was used to assess study quality.

Results

From 745 studies, four met inclusion criteria, reporting on 58 pediatric trauma patients. The age range was <1–18 years. Overall study quality was poor with only a single article of adequate quality. Twenty-nine percent of patients were cannulated at adult centers, the remaining at pediatric centers. Ninety-one percent were cannulated for ARDS and the remaining for cardiovascular collapse. Overall 60% of patients survived and the survival rate ranged from 50% to 100%. Seventy-seven percent underwent venoarterial cannulation and the remaining underwent veno-venous cannulation.

Conclusion

ECMO may be a therapeutic option in critically ill pediatric trauma patients. Consideration should be made for the expansion of ECMO utilization in pediatric trauma patients including its application for pediatric patients at adult trauma centers with ECMO capabilities.

Survival rate and Outcome of extracorporeal life support (ECLS) for treatment of acute cardiorespiratory failure in trauma patients

Extracorporeal life support (ECLS) remains the last option for cardiorespiratory stabilization of severe traumatic injured patients. Currently limited data are available and therefore, the current study assessed the survival rate and outcome of ECLS in a Level I trauma center. Between 2002 and 2016, 18 patients (7 females, 11 males) with an median age of 29.5 IQR 23.5 (range 1–64) years were treated with ECLS due to acute traumatic cardiorespiratory failure. Trauma mechanism, survival rate, ISS, SOFA, GCS, GOS, CPC, time to ECLS, hospital- and ICU stay, surgical interventions, complications and infections were retrospectively assessed. Veno-arterial ECLS was applied in 15 cases (83.3%) and veno-venous ECLS in 3 cases (16.6%). Survivors were significant younger than non-survivors (p = 0.0289) and had a lower ISS (23.5 (IQR 22.75) vs 38.5 (IQR 16.5), p = n.s.). The median time to ECLS cannulation was 2 (IQR 0,25) hours in survivors 2 (IQR 4) in non-survivors. Average GCS was 3 (IQR 9.25) at admission. Six patients (33.3%) survived and had a satisfying neurological outcome with a mean GOS of 5 (IQR 0.25) (p = n.s.). ECLS is a valuable treatment in severe injured patients with traumatic cardiorespiratory failure and improves survival with good neurological outcome. Younger patients and patients with a lower ISS are associated with a higher survival rate. Consideration of earlier cannulation in traumatic cardiorespiratory failure might be beneficial to improve survival.

AAST Critical Care Committee clinical consensus: ECMO, nutrition

The American Association for the Surgery of Trauma Critical Care Committee has developed clinical consensus guides to help with practical answers based on the best evidence available. These are focused in areas in which the levels of evidence may not be that strong and are based on a combination of expert consensus and research. Overall, quality of the research is mixed, with many studies suffering from small numbers and issues with bias. The first two of these focus on the use of extracorporeal membrane oxygenation in trauma patients and nutrition for the critically ill surgical/trauma patient.