Extracorporeal life support in trauma: Indications and techniques

BACKGROUND

Clarity about indications and techniques in extracorporeal life support (ECLS) in trauma is essential for timely and effective deployment, and to ensure good stewardship of an important resource. Extracorporeal life support deployments in a tertiary trauma center were reviewed to understand the indications, strategies, and tactics of ECLS in trauma.

METHODS

The provincial trauma registry was used to identify patients who received ECLS at a Level I trauma center and ECLS organization-accredited site between January 2014 and February 2021. Charts were reviewed for indications, technical factors, and outcomes following ECLS deployment. Based on this data, consensus around indications and techniques for ECLS in trauma was reached and refined by a multidisciplinary team discussion.

RESULTS

A total of 25 patients underwent ECLS as part of a comprehensive trauma resuscitation strategy. Eighteen patients underwent venovenous ECLS and seven received venoarterial ECLS. Nineteen patients survived the ECLS run, of which 15 survived to discharge. Four patients developed vascular injuries secondary to cannula insertion while four patients developed circuit clots. On multidisciplinary consensus, three broad indications for ECLS and their respective techniques were described: gas exchange for lung injury, extended damage control for severe injuries associated with the lethal triad, and circulatory support for cardiogenic shock or hypothermia.

CONCLUSION

The three broad indications for ECLS in trauma (gas exchange, extended damage control and circulatory support) require specific advanced planning and standardization of corresponding techniques (cannulation, circuit configuration, anticoagulation, and duration). When appropriately and effectively integrated into the trauma response, ECLS can extend the damage control paradigm to enable the management of complex multisystem injuries.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level IV.

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.

Early Use of Extracorporeal Membrane Oxygenation for Traumatically Injured Patients: A National Trauma Database Analysis

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) in acute trauma patients is a poorly characterized event. While ECMO most commonly has been deployed for advanced cardiopulmonary or respiratory failure following initial resuscitation, growing levels of evidence for out of hospital cardiac arrest support early ECMO cannulation as part of resuscitative efforts. We sought to perform a descriptive analysis evaluating traumatically injured patients, who were placed on ECMO, during their initial resuscitation period.

METHODS

We performed a retrospective analysis of the Trauma Quality Improvement Program Database from 2017 to 2019. All traumatically injured patients who received ECMO within the first 24 hours of their hospitalization were assessed. Descriptive statistics were used to define patient characteristics and injury patterns associated with the need for ECMO, while mortality represented the primary outcome evaluated.

RESULTS

A total of 696 trauma patients received ECMO during their hospitalization, of which 221 were placed on ECMO within the first 24 hours. Early ECMO patients were on average 32.5 years old, 86% male, and sustained a penetrating injury 9% of the time. The average ISS was 30.7, and the overall mortality rate was 41.2%. Prehospital cardiac arrest was noted in 18.2% of the patient population resulting in a 46.8% mortality. Of those who underwent resuscitative thoracotomy, a 53.3% mortality rate was present.

CONCLUSION

Early cannulation for ECMO in severely injured patients may provide an opportunity for rescue therapy following severe injury patterns. Further evaluation regarding the safety profile, cannulation strategies, and optimal injury patterns for these techniques should be evaluated.

Impact of Processed Electroencephalography in Cardiac Surgery: A Retrospective Analysis

OBJECTIVE

The use of brain function monitoring with processed electroencephalography (pEEG) during cardiac surgery is gaining interest for the optimization of hypnotic agent delivery during the maintenance of anesthesia. The authors sought to determine whether the routine use of pEEG-guided anesthesia is associated with a reduction of hemodynamic instability during cardiopulmonary bypass (CPB) separation and subsequently reduces vasoactive and inotropic requirements in the intensive care unit.

DESIGN

This is a retrospective cohort study based on an existing database.

SETTING

A single cardiac surgical center.

PARTICIPANTS

Three hundred patients undergoing cardiac surgery, under CPB, between December 2013 and March 2020.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One hundred and fifty patients had pEEG-guided anesthesia, and 150 patients did not have a pEEG-guided anesthesia. Multiple logistic regression demonstrated that pEEG-guided anesthesia was not associated with a successful CPB separation (p = 0.12). However, the use of pEEG-guided anesthesia reduced by 57% the odds of being in a higher category for vasoactive inotropic score compared to patients without pEEG (odds ratio = 0.43; 95% confidence interval: 0.26-0.73; p = 0.002). Duration of mechanical ventilation, fluid balance, and blood losses were also reduced in the pEEG anesthesia-guided group (p < 0.003), but there were no differences in organ dysfunction duration and mortality.

CONCLUSION

During cardiac surgery, pEEG-guided anesthesia allowed a reduction in the use of inotropic or vasoactive agents at arrival in the intensive care unit. However, it did not facilitate weaning from CPB compared to a group where pEEG was unavailable. A pEEG-guided anesthetic management could promote early vasopressor weaning after cardiac surgery.

Extracorporeal membrane oxygenation in trauma: A single institution experience and review of the literature

INTRODUCTION:

Limited options exist for cardiovascular support of the trauma patient in extremis. This patient population offers challenges that are often considered insurmountable. This article identifies a heterogeneous group of trauma patients in extremis who may benefit from extracorporeal membrane oxygenation.

METHODS:

Data were sourced from the medical records of all patients placed on extracorporeal membrane oxygenation following trauma at a Level I Trauma Center between 1 December 2016 and 1 December 2017.

RESULTS:

All patients were male (N = 7), mostly with blunt injuries (n = 5), with an average age of 41 years and with an average Injury Severity Scores of 33 (median = 34). Two out of seven patients survived (28.5%). Survivors tended to have a longer duration on extracorporeal membrane oxygenation (13.5 vs 3.8 days), had extracorporeal membrane oxygenation initiated later (15 vs 7.8 days), and had suffered a blunt injury. Two patients were initiated on veno-arterial extracorporeal membrane oxygenation (both non-survivors) and five were initiated on veno-venous extracorporeal membrane oxygenation (two survivors, three non-survivors). Five patients were heparinized immediately (one survivor, four non-survivors), and two patients were heparinized after clotting was noted in the circuit (one survivor, one non-survivor). Three of the seven (42.8%) patients suffered cardiac arrest either prior to, or during, the initiation of extracorporeal membrane oxygenation (all non-survivors).

DISCUSSION:

Extracorporeal membrane oxygenation use in the trauma patient in extremis is not standard; however, this article demonstrates that extracorporeal membrane oxygenation is feasible in a complex, heterogeneous patient population when treated at designated centers.

Extracorporeal membrane oxygenation improves coagulopathy in an experimental traumatic hemorrhagic model

Purpose

Hemorrhage is the most common cause of preventable death after trauma. Coagulopathy plays a central role in uncontrolled bleeding and is caused by multiple factors. Extracorporeal Membrane Oxygenation (ECMO) is an established treatment for patients with respiratory failure and has in recent years also been used in severely injured trauma patients with cardiopulmonary failure and coexisting bleeding shock. The aim of this study was to evaluate the effect of ECMO on hypothermia, acidosis, and coagulopathy in a traumatic hemorrhagic rabbit model.

Methods

After anesthesia and tracheostomy, ten New Zealand White rabbits sustained laparotomy, bilateral femur fractures and were hemorrhaged 45% of their estimated blood volume. After 90 min of hemorrhagic shock they were resuscitated with a standard transfusion protocol together with venoarterial ECMO (n = 5) or with a standard transfusion protocol only (n = 5) for 60 min. No systemic heparin was administered.

Results

ECMO during 60 min of resuscitation significantly increased heart rate (p = 0.01), mean arterial pressure (p = 0.01), body temperature (p = 0.01) and improved the metabolic acidosis, pH (p = 0.01), and lactate (p = 0.01). ECMO also improved the coagulation capacity measured in vitro by Rotational Thromboelastometry with a significant decrease in clot formation time (p < 0.01). This finding was confirmed in vivo with a significant reduction in the animals’ ear bleeding time (p < 0.01) and cuticle bleeding time (p < 0.01); 5/5 animals survived in the ECMO group and 3/5 animals survived in the control group.

Conclusions

Heparin-free ECMO stabilizes circulation, improves coagulation, and may impact short-time survival, during the first 60 min, in an experimental traumatic model with severe hemorrhagic shock.

Extracorporeal life support in polytraumatized patients

Major trauma is a leading cause of death, particularly amongst young patients. Conventional therapies for post-traumatic cardiovascular shock and acute pulmonary failure may sometimes be insufficient and even dangerous. New approaches to trauma care and novel salvage techniques are necessary to improve outcomes. Extracorporeal life support (ECLS) has proven to be effective in acute cardiopulmonary failure from different etiologies, particularly when conventional therapies fail. Since 2008 we have used ECLS as a rescue therapy in severe poly-trauma patients with refractory clinical setting (cardiogenic shock, cardiac arrest, and/or pulmonary failure). The rationale for using ECLS in trauma patients is to support cardiopulmonary function, providing adequate systemic perfusion and, therefore, avoiding consequent multi-organ failure and permitting organ recovery. From our data ECLS, utilizing heparin-coated support to avoid systemic anticoagulation, is a valuable option to support severely injured patients when conventional therapies are insufficient. It is safe, feasible, and effective in providing hemodynamic support and blood-gas exchange. Moreover, we have identified several pre-ECLS patient characteristics useful in predicting ECLS treatment appropriateness in severe poly-traumatized patients. These might be helpful in deciding whether the ECLS should be initiated in patients who are severely complex and compromised. Future improvements in materials and techniques are expected to make ECLS even easier and safer to manage, leading to a further extension of its use in severely injured patients.

Inverted-Takotsubo cardiomyopathy: severe refractory heart failure in poly-trauma patients saved by emergency extracorporeal life support

OBJECTIVES

The sequelae of severe poly-trauma may include myocardial dysfunction followed by acute heart failure and death. Inverted-Takotsubo cardiomyopathy (ITC) is a variant of stress cardiomyopathy, characterized by a contractile abnormality with extensive left ventricular circumferential dyskinesia or akinesia with a hyperkinetic apex. We report our experience with refractory cardiogenic shock and/or cardiac arrest, treated with extracorporeal life support.

METHODS

From June 2008 to December 2011, we treated 4 adult poly-trauma patients (3 men, 1 woman, mean age: 27.7 ± 13.5 years, mean ISS score 53.2 ± 15.9) with veno-arterial (V-A) extracorporeal life support for cardiopulmonary failure/cardiac arrest refractory to conventional treatment, due to inverted-Takotsubo cardiomyopathy. We used a miniaturized extracorporeal life support (ECLS) device.

RESULTS

ITC myocardial dysfunction appeared 15.4 ± 11.6 h after intensive care unit admission and rapidly evolved to refractory cardiopulmonary failure and cardiac arrest (within 4.8 ± 2.5 h of the onset). At ECLS, initiation median pH was 7.12 ± 0.14 (6.91-7.25), median lactate was 6.7 ± 2.8 (4-10) mmol/l and median vasoactive-inotropic score was 192.1 ± 50.6 µg/kg/min. Tissue perfusion improved significantly within 4 h on ECLS. Cardiac function improved gradually but consistently. Initial median ejection fraction was 14.2 ± 4.7% and median global longitudinal strain test was -7.4 ± 4.7. At complete cardiac recovery, they were 62.73 ± 7.8 and -18.43 ± 2.4%, respectively. After that, 2 patients survived and were sent to neurological rehabilitation before hospital discharge. In the other 2 cases, post-traumatic cerebral death occurred and they underwent organ explantation.

CONCLUSIONS

Rapid heparin-free ECLS may improve outcome in the most severe cases of poly-traumatized patients demonstrating refractory inverted-Takotsubo cardiomyopathy.

Passive leg raising can predict fluid responsiveness in patients placed on venovenous extracorporeal membrane oxygenation

Introduction

In ICUs, fluid administration is frequently used to treat hypovolaemia. Because volume expansion (VE) can worsen acute respiratory distress syndrome (ARDS) and volume overload must be avoided, predictive indicators of fluid responsiveness are needed. The purpose of this study was to determine whether passive leg raising (PLR) can be used to predict fluid responsiveness in patients with ARDS treated with venovenous extracorporeal membrane oxygenation (ECMO).

Methods

We carried out a prospective study in a university hospital surgical ICU. All patients with ARDS treated with venovenous ECMO and exhibiting clinical and laboratory signs of hypovolaemia were enrolled. We measured PLR-induced changes in stroke volume (ΔPLRSV) and cardiac output (ΔPLRCO) using transthoracic echocardiography. We also assessed PLR-induced changes in ECMO pump flow (ΔPLRPO) and PLR-induced changes in ECMO pulse pressure (ΔPLRPP) as predictors of fluid responsiveness. Responders were defined by an increase in stroke volume (SV) > 15% after VE.

Results

Twenty-five measurements were obtained from seventeen patients. In 52% of the measurements (n = 13), SV increased by > 15% after VE (responders). The patients' clinical characteristics appeared to be similar between responders and nonresponders. In the responder group, PLR significantly increased SV, cardiac output and pump flow (P < 0.001). ΔPLRSV values were correlated with VE-induced SV variations (r² = 0.72, P = 0.0001). A 10% increased ΔPLRSV predicted fluid responsiveness with an area under the receiver operating characteristic curve (AUC) of 0.88 ± 0.07 (95% confidence interval (CI₉₅): 0.69 to 0.97; P < 0.0001), 62% sensitivity and 92% specificity. On the basis of AUCs of 0.62 ± 0.11 (CI₉₅: 0.4 to 0.8; P = 0.31) and 0.53 ± 0.12 (CI₉₅: 0.32 to 0.73, P = 0.79), respectively, ΔPLRPP and ΔPLRPO did not predict fluid responsiveness.

Conclusions

In patients treated with venovenous ECMO, a > 10% ΔPLRSV may predict fluid responsiveness. ΔPLRPP and ΔPLRPO cannot predict fluid responsiveness.