Successful use of a new hand-held ECMO system in cardiopulmonary failure and bleeding shock after thrombolysis in massive post-partal pulmonary embolism

Thrombolysis in massive and submassive pulmonary embolism during pregnancy and the puerperium: a systematic review

Thrombolysis in high-risk pulmonary embolism (PE) patients is recommended worldwide; however, the evidence for thrombolysis during pregnancy and the immediate puerperium remains unclear. We conducted a systematic review from 1950 to 2019 through PubMed, Ovid/Willey, and Cochrane Library to assess the safety and effectiveness of thrombolysis during pregnancy and the immediate puerperium. Additionally, we characterized the clinical presentation, risk stratification, and diagnostic approach. We have communicated our results according to the PRISMA statement. We collected 141 records and, after critical assessment, included 47 case reports of 54 patients, including 43 and 11 patients during pregnancy and puerperium, respectively. During pregnancy, alteplase was the most frequent systemic thrombolytic agent used (67%), but only nine patients received the approved FDA regimen. With catheter-directed thrombolysis, low-dose thrombolytics and fragmentation were the most common regimens. Major bleeding occurred in 18% of cases, but there was no intracranial bleeding. One maternal death occurred secondary to refractory cardiogenic shock. Fetal mortality was 20%. During the immediate puerperium, nine patients received "off-label" first-, second-, and third-generation thrombolytic regimens, and four cases underwent catheter-directed thrombolysis. We observed nine major bleeding events, seven of which were from the uterine location and none of which were intracranial. In conclusion, overall, these data do not suggest prohibitive risk associated with thrombolysis for PE in pregnancy. Management of massive and high-risk submassive PE in pregnancy should be individualized to each patient. In the data presented, no fatal bleeding or intracranial bleeding was observed. Finally, future efforts should systematically collect and report data on high-risk PE in pregnancy and peripartum patients to improve the evidence-base clinical practice.

Management of high-risk pulmonary embolism in pregnancy

Pregnancy-associated high-risk pulmonary embolism (PE) is among the most frequent causes of maternal mortality in the Western world, by causing hemodynamic instability and circulatory failure through a large thrombotic pulmonary obstruction. The very challenging management of these dramatic situations comprises the need to quickly select a therapy of pulmonary reperfusion or hemodynamic replacement, while taking into account both maternal and fetal risks. In this review, we discuss the role of risk stratification in pregnancy-associated PE and the available evidence to support the use of thrombolysis, catheter-directed thrombectomy/thrombolysis, surgical embolectomy and extracorporeal membrane oxygenation. Despite the lack of comparative studies and solid evidence, most reported cases of high-risk pregnancy-associated PE have been treated with thrombolysis, with high maternal and fetal survivals, and thrombolysis is suggested by guidelines in life-threatening PE. For women in the peripartum and early post-partum period, non-fibrinolytic treatments may be preferred as a first-line treatment, if available, because of the particularly high bleeding risk. In all cases, pregnancy-associated high-risk PE requires a multidisciplinary approach involving PE response teams and obstetricians.

Extracorporeal Life Support in Hemorrhagic Conditions: A Systematic Review

Extracorporeal life support (ECLS) is indicated in refractory acute respiratory or cardiac failure. According to the need for anticoagulation, bleeding conditions (e.g., in trauma, pulmonary bleeding) have been considered a contraindication for the use of ECLS. However, there is increasing evidence for improved outcomes after ECLS support in hemorrhagic patients based on the benefits of hemodynamic support outweighing the increased risk of bleeding. We conducted a systematic literature search according to the PRISMA guidelines and reviewed publications describing ECLS support in hemorrhagic conditions. Seventy-four case reports, four case series, seven retrospective database observational studies, and one preliminary result of an ongoing study were reviewed. In total, 181 patients were identified in total of 86 manuscripts. The reports included patients suffering from bleeding caused by pulmonary hemorrhage (n = 53), trauma (n = 96), postpulmonary endarterectomy (n = 13), tracheal bleeding (n = 1), postpartum or cesarean delivery (n = 11), and intracranial hemorrhage (n = 7). Lower targeted titration of heparin infusion, heparin-free ECLS until coagulation is normalized, clamping of the endotracheal tube, and other ad hoc possibilities represent potential beneficial maneuvers in such conditions. Once the patient is cannulated and circulation restored, bleeding control surgery is performed for stabilization if indicated. The use of ECLS for temporary circulatory or respiratory support in critical patients with refractory hemorrhagic shock appears feasible considering tailored ECMO management strategies. Further investigation is needed to better elucidate the patient selection and ECLS management approaches.

Venoarterial Extracorporeal Membrane Oxygenation in Massive Pulmonary Embolism-Related Cardiac Arrest: A Systematic Review

OBJECTIVE

Management of patients experiencing massive pulmonary embolism-related cardiac arrest is controversial. Venoarterial extracorporeal membranous oxygenation has emerged as a potential therapeutic option for these patients. We performed a systematic review assessing survival and predictors of mortality in patients with massive PE-related cardiac arrest with venoarterial extracorporeal membranous oxygenation use.

DATA SOURCES

A literature search was started on February 16, 2020, and completed on March 16, 2020, using PubMed, Embase, Cochrane Central, Cinahl, and Web of Science.

STUDY SELECTION

We included all available literature that reported survival to discharge in patients managed with venoarterial extracorporeal membranous oxygenation for massive PE-related cardiac arrest.

DATA EXTRACTION

We extracted patient characteristics, treatment details, and outcomes.

DATA SYNTHESIS

About 301 patients were included in our systemic review from 77 selected articles (total screened, n = 1,115). About 183 out of 301 patients (61%) survived to discharge. Patients (n = 51) who received systemic thrombolysis prior to cannulation had similar survival compared with patients who did not (67% vs 61%, respectively; p = 0.48). There was no significant difference in risk of death if PE was the primary reason for admission or not (odds ratio, 1.62; p = 0.35) and if extracorporeal membranous oxygenation cannulation occurred in the emergency department versus other hospital locations (odds ratio, 2.52; p = 0.16). About 53 of 60 patients (88%) were neurologically intact at discharge or follow-up. Multivariate analysis demonstrated three-fold increase in the risk of death for patients greater than 65 years old (adjusted odds ratio, 3.08; p = 0.03) and six-fold increase if cannulation occurred during cardiopulmonary resuscitation (adjusted odds ratio, 5.67; p = 0.03).

CONCLUSIONS

Venoarterial extracorporeal membranous oxygenation has an emerging role in the management of massive PE-related cardiac arrest with 61% survival. Systemic thrombolysis preceding venoarterial extracorporeal membranous oxygenation did not confer a statistically significant increase in risk of death, yet age greater than 65 and cannulation during cardiopulmonary resuscitation were associated with a three- and six-fold risks of death, respectively.

Extracorporeal membrane oxygenation in pregnant and postpartum patients: a systematic review

PURPOSE

Information on the use of extracorporeal membrane oxygenation (ECMO) in obstetric patients is scarce. The objective was to conduct a systematic review examining ECMO use in pregnant and postpartum patients in order to identify indications leading to ECMO use and to assess mortality rates.

MATERIALS AND METHODS

PubMed, EMBASE, Cochrane Library, and SCOPUS were searched using the terms "extracorporeal membrane oxygenation" and "pregnancy" up to 1 November 2020. Case reports and case series reporting the use of ECMO in pregnancy were eligible. Data about maternal age, gestational age, diagnosis, type of ECMO, time on ECMO, pregnancy outcomes, and maternal survival were extracted from studies.

RESULTS

The search yielded 1696 citations, of which 125 were included. There were 213 obstetric patients treated with ECMO over a 30-year period. The frequency of reports increased considerably over the last decade. The majority of patients were treated in their third trimester (28.2%) or postpartum (32.9%). Most common etiologies included influenza-induced ARDS (27.7%), pulmonary embolism (13.6%), peripartum cardiomyopathy (11.7%), and infection (11.7%). Pregnancy outcomes ended with live births, either on ECMO (15.5%, 95% CI 10.6-20.4) or not on ECMO (58.3%, 95% CI 51.7-64.9), in fetal demise (8.9%, 95% CI 5.1-12.7), or in spontaneous or induced abortion on ECMO (4.2%, 95% CI 1.5-6.9) or not on ECMO (4.2%, 95% CI 1.5-6.9). Maternal survival was 79.3%.

CONCLUSION

Although women placed on ECMO had a high mortality rate, this is likely an indication of the severity of illness. Overall, ECMO appears to be a valid therapy for the temporary support of vital organs in severely ill pregnant women.

Extracorporeal Life Support in Pregnancy: A Systematic Review

Background The use of extracorporeal life support (ECLS) has expanded to include unique populations such as peripartum women. This systematic review aims to (1) quantify the number of cases and indications for ECLS in women during the peripartum period reported in the literature and (2) report maternal and fetal complications and outcomes associated with peripartum ECLS. Methods and Results This review was registered in PROSPERO (CRD42018108142). MEDLINE, Embase, and CINAHL were searched for case reports, case series, and studies reporting cases of ECLS during the peripartum period that reported one or more of the following outcomes: maternal survival, maternal complications, fetal survival, and/or fetal complications. Qualitative assessment of 221 publications evaluated the number of cases, clinical details, and maternal and fetal outcomes of ECLS during the peripartum period. There were 358 women included and 68 reported fetal outcomes in cases where the mother was pregnant at the time of cannulation. The aggregate maternal survival at 30 days was 270 (75.4%) and at 1 year was 266 (74.3%); fetal survival was 44 (64.7%). The most common indications for ECLS overall in pregnancy included acute respiratory distress syndrome 177 (49.4%), cardiac failure 67 (18.7%), and cardiac arrest 57 (15.9%). The most common maternal complications included mild to moderate bleeding 66 (18.4%), severe bleeding requiring surgical intervention 48 (13.4%), and intracranial neurologic morbidity 19 (5.3%). The most commonly reported fetal complications included preterm delivery 33 (48.5%) and neonatal intensive care unit admission 19 (27.9%). Conclusions Reported rates of survival in ECLS in pregnant and postpartum women are high and major complications relatively low.

Diagnosis, Treatment and Follow Up of Acute Pulmonary Embolism: Consensus Practice from the PERT Consortium

Pulmonary embolism (PE) is a life-threatening condition and a leading cause of morbidity and mortality. There have been many advances in the field of PE in the last few years, requiring a careful assessment of their impact on patient care. However, variations in recommendations by different clinical guidelines, as well as lack of robust clinical trials, make clinical decisions challenging. The Pulmonary Embolism Response Team Consortium is an international association created to advance the diagnosis, treatment, and outcomes of patients with PE. In this consensus practice document, we provide a comprehensive review of the diagnosis, treatment, and follow-up of acute PE, including both clinical data and consensus opinion to provide guidance for clinicians caring for these patients.

Extracorporeal membrane oxygenation in acute massive pulmonary embolism: a case series and review of the literature

Background:

Extracorporeal membrane oxygenation (ECMO) has been used to stabilize patients with massive pulmonary embolism though few reports describe this approach. We describe the presentation, management and outcomes of patients who received ECMO for massive pulmonary embolism (PE) in our pulmonary embolism response team (PERT) registry.

Methods:

We enrolled a consecutive cohort of patients with confirmed PE for whom PERT was activated and selected patients treated with ECMO. We prospectively captured clinical, therapeutic and outcome data at the time of PERT activation and during the follow-up period for up to 365 days.

Results:

Thirteen patients who had PERT activation with confirmed PE diagnosis have undergone ECMO since the initiation of our PERT program in 2012. The mean age was 49 ± 19 years. Six (46%) patients were female. All the patients had cardiac arrest, either as an initial presentation or in-hospital cardiac arrest after presentation. All the patients exhibited right ventricular (RV) dilation on echocardiogram with RV hypokinesis. Eight (62%) patients received systemic thrombolysis with intravenous tissue plasminogen activator (tPA) and three (23%) patients underwent catheter-directed thrombolysis therapy using the EKOS system (EKOS Corporation, Bothell, WA, USA). Four (31%) patients underwent surgical embolectomy. Mean ECMO duration was 5.5 days, ranging from 2-18 days. Thirty-day mortality was 31% and one-year mortality was 54%.

Conclusions:

Patients with massive pulmonary embolism who suffer a cardiac arrest have high morbidity and mortality. ECMO can be used in conjunction with systemic thrombolysis, catheter-directed therapy or as a bridge to surgical embolectomy.

Extracorporeal Life Support as Salvage Therapy for Massive Pulmonary Embolus and Cardiac Arrest in Pregnancy

BACKGROUND

Massive pulmonary embolus (PE) with prolonged cardiac arrest in the setting of pregnancy has few treatment options. Selections are further restricted if there are contraindications to the standard therapies of embolectomy and thrombolysis. We report a case of extracorporeal life support (ECLS) used as salvage therapy for a critically ill pregnant patient.

CASE REPORT

A 21-year-old woman presented to a small rural hospital with chest pain, dyspnea, hypoxia, and syncope. In their emergency department, she suffered 2 episodes of cardiac arrest requiring cardiopulmonary resuscitation, and fetal demise followed. A computed tomography scan revealed a saddle PE. She was transferred to our tertiary care hospital and arrived critically ill, on multiple vasopressors, and in cardiogenic shock. Because standard treatments, namely thrombolysis and embolectomy, were contraindicated in this case, ECLS was employed for 7 days. She was discharged home after 23 days, and at follow-up 5 months after her admission, she was found to have made a near-complete recovery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: ECLS is a viable option as salvage therapy for pregnant patients with massive PE who have contraindications to thrombolysis and embolectomy.

Advanced Cardiopulmonary Support for Pulmonary Embolism

Management of high-risk pulmonary embolism (PE) requires an understanding of the pathophysiology of PE, options for rapid clot reduction, critical care interventions, and advanced cardiopulmonary support. PE can lead to rapid respiratory and hemodynamic collapse via a complex sequence of events leading to acute right ventricular failure. Importantly, reduction in pulmonary vascular resistance must be accomplished either by systemic thrombolytics, catheter directed thrombolytics, endovascular clot extraction, or surgical embolectomy. There are important advances in these techniques all of which have a niche role in the cardiopulmonary stabilization of critically ill patient with PE. Critical care support surrounding the above interventions is necessary. Maintenance of systemic perfusion and cardiac output may require careful titration of vasopressors, inotropes, and preload. Extreme caution should be taken with approach to intubation and positive pressure ventilation. A hemodynamically neutral induction with preparations for circulatory collapse should be the goal. Once intubated, the effect of positive pressure on pulmonary vascular resistance and right ventricular hemodynamics is necessary. Veno-arterial extra corporeal membrane oxygenation plays an increasingly important role in the stabilization of the hemodynamically collapsed patient who either has a contraindication to systemic lytics, failed systemic lytics, or requires a bridge to surgical or catheter embolectomy. Veno-arterial extra corporeal membrane oxygenation has also been used alone to stabilize the circulation until hemodynamics normalize on anticoagulation and has also been used in tenuous patient as a safety net for endovascular procedures.

Thrombolysis with intravenous recombinant tissue plasminogen activator during early postpartum period: a review of the literature

Thromboembolic events are one of the leading causes of maternal death during the postpartum period. Postpartum thrombolytic therapy with recombinant tissue plasminogen activator (rt-PA) is controversial because the treatment may lead to massive bleeding. Data centralization may be beneficial for analyzing the safety and effectiveness of systemic thrombolysis during the early postpartum period. We performed a computerized MEDLINE and EMBASE search. We collected data for 13 cases of systemic thrombolytic therapy during the early postpartum period, when limiting the early postpartum period to 48 hours after delivery. Blood transfusion was necessary in all cases except for one (12/13; 92%). In seven cases (7/13; 54%), a large amount of blood was required for transfusion. Subsequent laparotomy to control bleeding was required in five cases (5/13; 38%), including three cases of hysterectomy and two cases of hematoma removal, all of which involved cesarean delivery. In cases of transvaginal delivery, there was no report of laparotomy. The occurrence of severe bleeding was high in relation to cesarean section, compared with vaginal deliveries. Using rt-PA in relation to cesarean section might be worth avoiding. However, the paucity of data in the literature makes it difficult to assess the ultimate outcomes and safety of this treatment.

Outcome and Management of Refractory Respiratory Failure With Timely Extracorporeal Membrane Oxygenation: Single-Center Experience With Legionella Pneumonia

OBJECTIVE:

To analyze the management and outcome of patients with refractory respiratory failure complicating severe Legionella pneumonia rescued with extracorporeal membrane oxygenation (ECMO) in our Center.

DESIGN AND SETTING:

Observational study of patients with refractory respiratory failure treated with ECMO in Hospital S.João (Porto, Portugal), between November 2009 and September 2016.

PARTICIPANTS:

A total of 112 patients rescued with ECMO, of which 14 had Legionella pneumonia.

RESULTS:

Patients with Legionella pneumonia were slightly older than patients with acute respiratory failure of other etiologies (51 [48-56] vs 45 [35-54]), but with no significant differences in acute respiratory failure severity between groups: Pao₂/Fio₂ ratio 67 (60-75) versus 69 (55-85) and Respiratory Extracorporeal Membrane Oxygenation Survival Prediction score 4 (1-5) versus 2 (-1-4), respectively. Legionella pneumonia was associated with earlier ECMO initiation (days of invasive mechanical ventilation [IMV] before ECMO: 2.0 [1.0-4.0] vs 5.0 [2.0-9.5]). After IMV adjustment to "lung rest" settings, this group presented higher respiratory system (RS) static compliance (28.7 [18.8-37.4] vs 16.0 [10.0-20.8] mL/cmH₂O) but required higher ECMO support (blood flow 5.0 [4.3-5.4] vs 4.2 [3.6-4.8]). Patients with Legionella pneumonia had shorter IMV (16 [14-23] vs 27 [20-42] days) and lower incidence of intensive care unit nosocomial infections (35.7% vs 64.3%), with a trend to higher hospital survival (85.7% vs 62.2%; P = .13).

CONCLUSION:

In Legionella pneumonia complicated by refractory respiratory failure, ECMO support allowed patient stabilization under lung protective ventilation and high survival rates. Timely ECMO referral should be considered for Legionella pneumonia failing conventional treatment.

Extracorporeal life support (ECLS) for cardiopulmonary resuscitation (CPR) with pulmonary embolism in surgical patients – a case series

Background:

Extracorporeal life support (ECLS) devices maintain the circulation and oxygenation of organs during acute right ventricular failure and cardiogenic shock, bypassing the lungs. A pulmonary embolism can cause this life-threatening condition. ECLS is a considerably less invasive treatment than surgical embolectomy. Whether to bridge embolectomy or for a therapeutic purpose, ECLS is used almost exclusively following failure of all other therapeutic options.

Methods:

From January 1, 2008 to June 30, 2014, five patients in cardiac arrest and with diagnosed pulmonary embolism (PE) were cannulated with the ECLS system.

Results:

PE was diagnosed using computer tomography scanning or echocardiography. Cardiac arrest was witnessed in the hospital in all cases and CPR (cardiopulmonary resuscitation) was initiated immediately. Cannulation of the femoral vein and femoral artery was always performed under CPR conditions. Right heart failure regressed during the ECLS therapy, usually under a blood flow of 4-5 L/min after 48 hours. Three patients were weaned from ECLS and one patient became an organ donor. Finally, two of the five PE patients treated with ECLS were discharged from inpatient treatment without neurological dysfunction. The duration of ECLS therapy depends on the patient’s condition. Irreversible damage to the organs after hypoxemia limits ECLS treatment and leads to futile multiorgan failure. Hemorrhages after thrombolysis and cerebral dysfunction were further complications.

Conclusions:

Veno-arterial cannulation for ECLS can be feasibly achieved and should be established during active CPR for cardiac arrest. In the case of PE, the immediate diagnosis and rapid implantation of the system are decisive for therapeutic success.

[Arteriovenous extracorporeal membrane oxygenation (ECMO). A therapeutic option for fulminant pulmonary embolism]

According to the guidelines of the European (2008) and German Societies of Cardiology (2009) thrombolysis is recommended for patients with pulmonary embolisms presenting with cardiogenic shock (recommendation level I, evidence level A). If there are contraindications or thrombolysis is not successful surgical embolectomy should be considered (recommendation level I, evidence level C). Additional options are catheter-based therapies in the proximal pulmonary artery (recommendation level IIb, evidence level C). The use of arteriovenous extracorporeal membrane oxygenation ( ECMO) was not included in these guidelines. A literature search in PubMed resulted in some case reports of the successful use of arteriovenous ECMO for resuscitation in patients with severe pulmonary embolisms following failed thrombolysis. In this article we present the case report of a patient who developed fulminant pulmonary embolism immediately after surgery. The patient was still in cardiogenic shock despite thrombolysis but the condition was stable following implementation of an arteriovenous ECMO. Acute heart failure and hypoxemia of all organs are the main symptoms of massive pulmonary embolisms. The use of arteriovenous ECMO represents a therapeutic option for life-threatening pulmonary embolism. A decisive factor for success is immediate diagnosis and rapid implementation of the system.

Portable miniaturized extracorporeal membrane oxygenation systems for H1N1-related severe acute respiratory distress syndrome: a case series

BACKGROUND

Technological advances improved the practice of "modern" extracorporeal membrane oxygenation (ECMO). In the present report, we describe the experience of a referral ECMO center using portable miniaturized ECMO systems for H1N1-related severe acute respiratory distress syndrome (ARDS).

METHODS

An observational study of all patients with H1N1-associated ARDS treated with ECMO in Hospital S. João (Porto, Portugal) between November 2009 and April 2011 was performed. Extracorporeal membrane oxygenation support was established using either ELS or Cardiohelp systems (Maquet-Cardiopulmonary-AG, Hirrlingen, Germany).

RESULTS

Ten adult patients with severe ARDS secondary to H1N1 infection (Pao(2)/fraction of inspired oxygen, 69 mm Hg [56-84]; Murray score, 3.5 [3.5-3.8]) were included, and 60% survived to hospital discharge. Five patients were uneventfully transferred on ECMO from referring hospitals to our center by ambulance. Six patients were treated during the first postpandemic influenza season. All patients were treated with oseltamivir, and 1 received in addition zanamivir. Four patients received corticosteroids. Nosocomial infection was the most common complication (40%). Of the 4 deaths, 2 were caused by hemorrhagic shock; 1, by irreversible multiple organ failure; and 1, by refractory septic shock.

CONCLUSION

In our experience, ECMO support was a valuable therapeutic option for H1N1-related severe ARDS. The use of portable miniaturized systems allowed urgent rescue of patients from referring hospitals and safe interhospital and intrahospital transport during ECMO support.

Successful Treatment of Peripartum Massive Pulmonary Embolism with Extracorporeal Membrane Oxygenation and Catheter-Directed Pulmonary Thrombolytic Therapy

Chronic thromboembolic pulmonary hypertension during pregnancy is uncommon but is associated with maternal mortality in excess of 35%. We report a case of decompensated thromboembolic pulmonary hypertension requiring emergency caesarean section and postpartum treatment with extracorporeal membrane oxygenation and thrombolytic therapy with urokinase. The use of extracorporeal membrane oxygenation, catheter-directed pulmonary thrombolytic therapy and other pulmonary vasodilators for management of this life-threatening disease is discussed.

Out-of-hospital extracorporeal life support for cardiac arrest-A case report

We report the use of out-of-hospital extracorporeal life support (ECLS) in cardiac arrest. We treated a 9-year-old girl with cardiac arrest after warm-water drowning with percutaneous venoarterial extracorporeal membrane oxygenation (ECMO) using a new portable Mini-ECMO system. A beating-heart circulation was reestablished on ECMO, but, unfortunately, our patient did not survive. This case shows that Mini-ECMO support can be used to restore an effective circulation and gas exchange in the out-of-hospital setting.

Pulmonary vascular and right ventricular dysfunction in adult critical care: current and emerging options for management: a systematic literature review

INTRODUCTION

Pulmonary vascular dysfunction, pulmonary hypertension (PH), and resulting right ventricular (RV) failure occur in many critical illnesses and may be associated with a worse prognosis. PH and RV failure may be difficult to manage: principles include maintenance of appropriate RV preload, augmentation of RV function, and reduction of RV afterload by lowering pulmonary vascular resistance (PVR). We therefore provide a detailed update on the management of PH and RV failure in adult critical care.

METHODS

A systematic review was performed, based on a search of the literature from 1980 to 2010, by using prespecified search terms. Relevant studies were subjected to analysis based on the GRADE method.

RESULTS

Clinical studies of intensive care management of pulmonary vascular dysfunction were identified, describing volume therapy, vasopressors, sympathetic inotropes, inodilators, levosimendan, pulmonary vasodilators, and mechanical devices. The following GRADE recommendations (evidence level) are made in patients with pulmonary vascular dysfunction: 1) A weak recommendation (very-low-quality evidence) is made that close monitoring of the RV is advised as volume loading may worsen RV performance; 2) A weak recommendation (low-quality evidence) is made that low-dose norepinephrine is an effective pressor in these patients; and that 3) low-dose vasopressin may be useful to manage patients with resistant vasodilatory shock. 4) A weak recommendation (low-moderate quality evidence) is made that low-dose dobutamine improves RV function in pulmonary vascular dysfunction. 5) A strong recommendation (moderate-quality evidence) is made that phosphodiesterase type III inhibitors reduce PVR and improve RV function, although hypotension is frequent. 6) A weak recommendation (low-quality evidence) is made that levosimendan may be useful for short-term improvements in RV performance. 7) A strong recommendation (moderate-quality evidence) is made that pulmonary vasodilators reduce PVR and improve RV function, notably in pulmonary vascular dysfunction after cardiac surgery, and that the side-effect profile is reduced by using inhaled rather than systemic agents. 8) A weak recommendation (very-low-quality evidence) is made that mechanical therapies may be useful rescue therapies in some settings of pulmonary vascular dysfunction awaiting definitive therapy.

CONCLUSIONS

This systematic review highlights that although some recommendations can be made to guide the critical care management of pulmonary vascular and right ventricular dysfunction, within the limitations of this review and the GRADE methodology, the quality of the evidence base is generally low, and further high-quality research is needed.

Extracorporeal membrane oxygenation in severe trauma patients with bleeding shock

AIM OF THE STUDY

Death to trauma is caused by disastrous injuries on scene, bleeding shock or acute respiratory failure (ARDS) induced by trauma and massive blood transfusion. Extracorporeal membrane oxygenation (ECMO) can be effective in severe cardiopulmonary failure, but preexisting bleeding is still a contraindication for its use. We report our first experiences in application of initially heparin-free ECMO in severe trauma patients with resistant cardiopulmonary failure and coexisting bleeding shock retrospectively and describe blood coagulation management on ECMO.

METHODS

From June 2006 to June 2009 we treated adult trauma patients (n=10, mean age: 32+/-14 years, mean ISS score 73+/-4) with percutaneous veno-venous (v-v) ECMO for pulmonary failure (n=7) and with veno-arterial (v-a) ECMO in cardiopulmonary failure (n=3). Diagnosis included polytrauma (n=9) and open chest trauma (n=1). We used a new miniaturised ECMO device (PLS-Set, MAQUET Cardiopulmonary AG, Hechingen, Germany) and performed initially heparin-free ECMO.

RESULTS

Prior to ECMO median oxygenation ratio (OR) was 47 (36-90) mmHg, median paCO(2) was 67 (36-89) mmHg and median norepinephrine demand was 3.0 (1.0-13.5) mg/h. Cardiopulmonary failure was treated effectively with ECMO and systemic gas exchange and blood flow improved rapidly within 2 h on ECMO in all patients (median OR 69 (52-263) mmHg, median paCO(2) 41 (22-85) mmHg. 60% of our patients had recovered completely.

CONCLUSIONS

Initially heparin-free ECMO support can improve therapy and outcome even in disastrous trauma patients with coexisting bleeding shock.

Reserve-driven flow control for extracorporeal life support: proof of principle

Extracorporeal life support systems lack volume-buffering capacity. Therefore, any decrease in venous intravascular volume available for drainage may result in acutely reduced support flow. We recently developed a method to quantify drainable volume and now conceived a reserve-driven pump control strategy, which is different from existing pressure or flow servo control schemes. Here, we give an outline of the algorithm and present animal experimental data showing proof of principle. With an acute reduction in circulatory volume (10-15%), pump flow immediately dropped from 4.1 to 1.9 l/min. Our pump control algorithm was able to restore bypass flow to 3.2 l/min (about 80% of the original level) and, thereby, reduced the duration of the low-flow condition. This demonstrates that a reserve-driven pump control strategy, based on the continuous monitoring of drainable volume, may maintain extracorporeal circulatory support flow, despite serious changes in filling conditions.