Hemodynamic effects of fluid loading in acute massive pulmonary embolism

Mechanical Circulatory Support Devices in Patients with High-Risk Pulmonary Embolism

Pulmonary embolism (PE) is a common acute cardiovascular condition. Within this review, we discuss the incidence, pathophysiology, and treatment options for patients with high-risk and massive pulmonary embolisms. In particular, we focus on the role of mechanical circulatory support devices and their possible therapeutic benefits in patients who are unresponsive to standard therapeutic options. Moreover, attention is given to device selection criteria, weaning protocols, and complication mitigation strategies. Finally, we underscore the necessity for more comprehensive studies to corroborate the benefits and safety of MCS devices in PE management.

Intermediate-Risk and High-Risk Pulmonary Embolism: Recognition and Management: Cardiology Clinics: Cardiac Emergencies

Pulmonary embolism (PE) is the third most common cause of cardiovascular death. Every specialty of medical practitioner will encounter PE in their patients, and should be prepared to employ contemporary strategies for diagnosis and initial risk-stratification. Treatment of PE is based on risk-stratification, with anticoagulation for all patients, and advanced modalities including systemic thrombolysis, catheter-directed therapies, and mechanical circulatory supports utilized in a manner paralleling PE severity and clinical context.

Comparison of diuretics and fluid expansion in the initial treatment of patients with normotensive acute pulmonary embolism: a systematic review and meta-analysis

BACKGROUND

Right ventricular (RV) dysfunction is the main cause of death in patients with normotensive acute pulmonary embolism (PE). The optimal management for this subset of patients remains uncertain. This systematic review and meta-analysis focused on the comparison of diuretics and fluid expansion in patients with acute PE presenting with RV dysfunction and haemodynamic stability.

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines considering only RTCs. The authors searched the traditional and grey literature through 1 November 2022. Meta-analysis used open source packages in R. Inverse variance fixed-effects models with OR as the effect measure were used for primary analyses. The main outcomes defined in this review protocol included pulmonary arterial systolic pressure (PASP), creatinine value changes and N-terminal pro-B-type natriuretic peptide during the first 24 hours.

RESULTS

Four studies with a total of 452 patients met the inclusion criteria. The baseline characteristics of patients were similar across all studies. Overall, patients receiving diuretics had a significant 24 hours reduction in pro-B-type natriuretic peptide (standard mean difference of -41.97; 95% CI -65.79 to -18.15), and PASP (standard mean difference of -5.96; 95% CI -8.06 to -3.86). This group had significantly higher creatinine levels (standard mean difference of 7.74; 95% CI 5.04 to 10.45). The quality of the studies was heterogeneous; two had a low risk of bias, and the other two had a high risk of bias.

CONCLUSIONS

Very few studies have compared the efficacy and safety of diuretics and fluid expansion in normotensive patients with acute PE with RV failure. Overall, furosemide appears to reduce RV dysfunction in this subset of patients compared with fluid expansion. Further research is required to confirm these findings.

Anesthetic management in patients having catheter-based thrombectomy for acute pulmonary embolism: A narrative review

Pulmonary embolism is the third leading cause of cardiovascular death. Novel percutaneous catheter-based thrombectomy techniques are rapidly becoming popular in high-risk pulmonary embolism - especially in the presence of contraindications to thrombolysis. The interventional nature of these procedures and the risk of sudden cardiorespiratory compromise requires the presence of an anesthesiologist. Facilitating catheter-based thrombectomy can be challenging since qualifying patients are often critically ill. The purpose of this narrative review is to provide guidance to anesthesiologists for the assessment and management of patients having catheter-based thrombectomy for acute pulmonary embolism. First, available techniques for catheter-based thrombectomy are reviewed. Then, we discuss definitions and application of common risk stratification tools for pulmonary embolism, and how to assess patients prior to the procedure. An adjudication of risks and benefits of anesthetic strategies for catheter-based thrombectomy follows. Specifically, we give guidance and rationale for use monitored anesthesia care and general anesthesia for these procedures. For both, we review strategies for assessing and mitigating hemodynamic perturbations and right ventricular dysfunction, ranging from basic monitoring to advanced inodilator therapy. Finally, considerations for management of right ventricular failure with mechanical circulatory support are discussed.

High and intermediate risk pulmonary embolism in the ICU

Pulmonary embolism (PE) is a common and important medical emergency, encountered by clinicians across all acute care specialties. PE is a relatively uncommon cause of direct admission to the intensive care unit (ICU), but these patients are at high risk of death. More commonly, patients admitted to ICU develop PE as a complication of an unrelated acute illness. This paper reviews the epidemiology, diagnosis, risk stratification, and particularly the management of PE from a critical care perspective. Issues around prevention, anticoagulation, fibrinolysis, catheter-based techniques, surgical embolectomy, and extracorporeal support are discussed.

Medical and Mechanical Circulatory Support of the Failing Right Ventricle

PURPOSE OF REVIEW

To describe medical therapies and mechanical circulatory support devices used in the treatment of acute right ventricular failure.

RECENT FINDINGS

Experts have proposed several algorithms providing a stepwise approach to medical optimization of acute right ventricular failure including tailored volume administration, ideal vasopressor selection to support coronary perfusion, inotropes to restore contractility, and pulmonary vasodilators to improve afterload. Studies have investigated various percutaneous and surgically implanted right ventricular assist devices in several clinical settings. The initial management of acute right ventricular failure is often guided by invasive hemodynamic data tracking parameters of circulatory function with the use of pharmacologic therapies. Percutaneous microaxial and centrifugal extracorporeal pumps bypass the failing RV and support circulatory function in severe cases of right ventricular failure.

Mechanical Circulatory Support and Critical Care Management of High-Risk Acute Pulmonary Embolism

Hemodynamically significant pulmonary embolism (PE) remains a widely prevalent, underdiagnosed condition associated with mortality rates as high as 30%. The main driver of poor outcomes is acute right ventricular failure that remains clinically challenging to diagnose and requires critical care management. Treatment of high-risk (or massive) acute PE has traditionally included systemic anticoagulation and thrombolysis. Mechanical circulatory support, including both percutaneous and surgical approaches, are emerging as treatment options for refractory shock due to acute right ventricular failure in the setting of high-risk acute pulmonary embolism.

Hemodynamic and respiratory support in pulmonary embolism: a narrative review

Pulmonary embolism is a common and potentially fatal disease, with a significant burden on health and survival. Right ventricular dysfunction and hemodynamic instability are considered two key determinants of mortality in pulmonary embolism, which can reach up to 65% in severe cases. Therefore, timely diagnosis and management are of paramount importance to ensure the best quality of care. However, hemodynamic and respiratory support, both major constituents of management in pulmonary embolism, associated with cardiogenic shock or cardiac arrest, have been given little attention in recent years, in favor of other novel advances such as systemic thrombolysis or direct oral anticoagulants. Moreover, it has been implied that current recommendations regarding this supportive care lack enough robustness, further complicating the problem. In this review, we critically discuss and summarize the current literature concerning the hemodynamic and respiratory support in pulmonary embolism, including fluid therapy, diuretics, pharmacological support with vasopressors, inotropes and vasodilators, oxygen therapy and ventilation, and mechanical circulatory support with veno-arterial extracorporeal membrane oxygenation and right ventricular assist devices, while also providing some insights into contemporary research gaps.

Current Diagnosis and Management of Acute Pulmonary Embolism: A Strategy for General Practitioners in Emergency Department

Pulmonary embolism (PE) is a disease with a relatively good prognosis when diagnosed and treated properly. This review aims to analyse available data and combine them into algorithms that physicians can use in the emergency department for quick decision-making in diagnosing and treating PE. The available data show that PE can be excluded through highly sensitive clinical decision rules, i.e. Pulmonary Embolism Rule-Out Criteria (PERC), Wells criteria, and Revised Geneva criteria, combined with D-dimer assessment. In cases where PE could not be excluded through the mentioned strategies, imaging modalities, such as compression ultrasonography (CUS), computed tomographic pulmonary angiography (CTPA), and planar ventilation/perfusion (V/Q) scan, are indicated for a definite diagnosis. Once a diagnosis has been made, treatment of PE depends on its mortality risk as patients are divided into low-, intermediate-, and high-risk cases. High-risk cases are treated for their hemodynamic instability, given parenteral or oral anticoagulant therapy, and are indicated for reperfusion therapy. Intermediate-risk PE is only given parenteral or oral anticoagulants and reperfusion is indicated when anticoagulants fail. Low-risk cases are given oral anticoagulants and based on the Hestia criteria, patients may be discharged and treated as outpatients.

ISCCM Guidelines for Hemodynamic Monitoring in the Critically Ill

Hemodynamic assessment along with continuous monitoring and appropriate therapy forms an integral part of management of critically ill patients with acute circulatory failure. In India, the infrastructure in ICUs varies from very basic facilities in smaller towns and semi-urban areas, to world-class, cutting-edge technology in corporate hospitals, in metropolitan cities. Surveys and studies from India suggest a wide variation in clinical practices due to possible lack of awareness, expertise, high costs, and lack of availability of advanced hemodynamic monitoring devices. We, therefore, on behalf of the Indian Society of Critical Care Medicine (ISCCM), formulated these evidence-based guidelines for optimal use of various hemodynamic monitoring modalities keeping in mind the resource-limited settings and the specific needs of our patients. When enough evidence was not forthcoming, we have made recommendations after achieving consensus amongst members. Careful integration of clinical assessment and critical information obtained from laboratory data and monitoring devices should help in improving outcomes of our patients.

How to cite this article

Kulkarni AP, Govil D, Samavedam S, Srinivasan S, Ramasubban S, Venkataraman R, et al. ISCCM Guidelines for Hemodynamic Monitoring in the Critically Ill. Indian J Crit Care Med 2022;26(S2):S66-S76.

Progress in interventional radiology treatment of pulmonary embolism: A brief review

Pulmonary embolism represents a common life-threatening condition. Prompt identification and treatment of this pathological condition are mandatory. In cases of massive pulmonary embolism and hemodynamic instability or right heart failure, interventional radiology treatment for pulmonary embolism is emerging as an alternative to medical treatment (systemic thrombolysis) and surgical treatment. Interventional radiology techniques include percutaneous endovascular catheter directed therapies as selective thrombolysis and thrombus aspiration, which can prove useful in cases of failure or infeasibility of medical and surgical approaches.

An Update on the Management of Acute High-Risk Pulmonary Embolism

Hemodynamic instability and right ventricular (RV) dysfunction are the key determinants of short-term prognosis in patients with acute pulmonary embolism (PE). High-risk PE encompasses a wide spectrum of clinical situations from sustained hypotension to cardiac arrest. Early recognition and treatment tailored to each individual are crucial. Systemic fibrinolysis is the first-line pulmonary reperfusion therapy to rapidly reverse RV overload and hemodynamic collapse, at the cost of a significant rate of bleeding. Catheter-directed pharmacological and mechanical techniques ensure swift recovery of echocardiographic parameters and may possess a better safety profile than systemic thrombolysis. Further clinical studies are mandatory to clarify which pulmonary reperfusion strategy may improve early clinical outcomes and fill existing gaps in the evidence.

A systemic congestive index (systemic pulse pressure to central venous pressure ratio) predicts adverse outcomes in patients undergoing valvular heart surgery

Background and Aims

Invasive hemodynamics may provide a more nuanced assessment of cardiac function and risk phenotyping in patients undergoing cardiac surgery. The systemic pulse pressure (SPP) to central venous pressure (CVP) ratio represents an integrated index of right and left ventricular function and thus may demonstrate an association with valvular heart surgery outcomes. This study hypothesized that a low SPP/CVP ratio would be associated with mortality in valvular surgery patients.

Methods

This retrospective cohort study examined adult valvular surgery patients with preoperative right heart catheterization from 2007 through 2016 at a single tertiary medical center (n = 215). Associations between the SPP/CVP ratio and mortality were investigated with univariate and multivariate analyses.

Results

Among 215 patients (age 69.7 ± 12.4 years; 55.8% male), 61 died (28.4%) over a median follow‐up of 5.9 years. A SPP/CVP ratio <7.6 was associated with increased mortality (relative risk 1.70, 95% confidence interval [CI] 1.08–2.67, p = .019) and increased length of stay (11.56 ± 13.73 days vs. 7.93 ± 4.92 days, p = .016). It remained an independent predictor of mortality (adjusted odds ratio 3.99, 95% CI 1.47–11.45, p = .008) after adjusting for CVP, mean pulmonary artery pressure, aortic stenosis, tricuspid regurgitation, smoking status, diabetes mellitus, dialysis, and cross‐clamp time.

Conclusions

A low SPP/CVP ratio was associated with worse outcomes in patients undergoing valvular heart surgery. This metric has potential utility in preoperative risk stratification to guide patient selection, prognosis, and surgical outcomes.

Diuretics Versus Volume Expansion in the Initial Management of Acute Intermediate High-Risk Pulmonary Embolism

AIMS

The very early management of pulmonary embolism (PE), a part from antithrombotic treatment, has been little studied. Our aim was to compare the effects of diuretic therapy (DT) versus volume expansion (VE) in patients hospitalized for PE with RV dysfunction.

METHODS AND RESULTS

We conducted a randomized open-label multicentric study including patients with intermediate high-risk PE. Patients were randomized between diuretics or saline infusion. The primary endpoint was time to troponin (Tp) normalization. Secondary endpoints were time to normalization of B-type natriuretic peptide (BNP), changes in echocardiographic RV function parameters and treatment tolerance. Sixty patients presenting intermediate high-risk PE were randomized. Thirty received DT and 30 VE. We noted no changes in Tp kinetics between the two groups. In contrast, faster normalization of BNP was obtained in the DT group: 56 [28-120] vs 108 [48-144] h: p = 0.05, with a shorter time to 50%-decrease from peak value 36 [24-48] vs 54 [41-67] h, p = 0.003 and a higher rate of patients with a lower BNP concentration within the first 12 h (42% vs 12% p < 0.001). RV echocardiographic parameters were unchanged between the groups. One dose 40 mg furosemide was well-tolerated and not associated with any serious adverse events.

CONCLUSION

In the acute management of intermediate high-risk PE, initial therapy including diuretic treatment is well-tolerated and safe. Although changes in Tp kinetics and echocardiographic RV dysfunction parameters did not differ, normalization of BNP is achieved more quickly in the DT group. This finding, which need to be confirmed in trials with clinical end points, may reflects a rapid improvement in RV function using one dose 40 mg furosemide.

TRIAL REGISTRY

Clinical Trial Registration NCT02531581.

Diuretic vs. placebo in intermediate-risk acute pulmonary embolism: a randomized clinical trial

AIMS

The role of diuretics in patients with intermediate-risk pulmonary embolism (PE) is controversial. In this multicentre, double-blind trial, we randomly assigned normotensive patients with intermediate-risk PE to receive either a single 80 mg bolus of furosemide or a placebo.

METHODS AND RESULTS

Eligible patients had at least a simplified PE Severity Index (sPESI) ≥1 with right ventricular dysfunction. The primary efficacy endpoint assessed 24 h after randomization included (i) absence of oligo-anuria and (ii) normalization of all sPESI items. Safety outcomes were worsening renal function and major adverse outcomes at 48 hours defined by death, cardiac arrest, mechanical ventilation, or need of catecholamine. A total of 276 patients underwent randomization; 135 were assigned to receive the diuretic, and 141 to receive the placebo. The primary outcome occurred in 68/132 patients (51.5%) in the diuretic and in 49/132 (37.1%) in the placebo group (relative risk = 1.30, 95% confidence interval 1.04-1.61; P = 0.021). Major adverse outcome at 48 h occurred in 1 (0.8%) patients in the diuretic group and 4 patients (2.9%) in the placebo group (P = 0.19). Increase in serum creatinine level was greater in diuretic than placebo group [+4 µM/L (-2; 14) vs. -1 µM/L (-11; 6), P < 0.001].

CONCLUSION

In normotensive patients with intermediate-risk PE, a single bolus of furosemide improved the primary efficacy outcome at 24 h and maintained stable renal function. In the furosemide group, urine output increased, without a demonstrable improvement in heart rate, systolic blood pressure, or arterial oxygenation.ClinicalTrials.gov identifier NCT02268903.

Rare Presentation of Deep Vein Thrombosis and Submassive Pulmonary Emboli Due to Hypercoagulable State With Supratherapeutic Anticoagulation

We present a case of an elderly male with multiple co-morbidities, including atrial fibrillation on warfarin and recently diagnosed left lower extremity deep vein thrombosis (DVT), who presented to the emergency department for dyspnea. He was found to be hypoxic and mildly hypotensive. He was diagnosed with submassive pulmonary emboli (PE) despite having a supratherapeutic international normalized ratio (INR). In this case report, the clinical presentation, diagnostic workup, and management of this patient are discussed.

High Central Venous Pressure and Right Ventricle Size Are Related to Non-decreased Left Ventricle Stroke Volume After Negative Fluid Balance in Critically Ill Patients: A Single Prospective Observational Study

Background: Optimal adjustment of cardiac preload is essential for improving left ventricle stroke volume (LVSV) and tissue perfusion. Changes in LVSV caused by central venous pressure (CVP) are the most important concerns in the treatment of critically ill patients. Objectives: This study aimed to clarify the changes in LVSV after negative fluid balance in patients with elevated CVP, and to elucidate the relationship between the parameters of right ventricle (RV) filling state and LVSV changes. Methods: This prospective cohort study included patients with high central venous pressure (CVP) (≥8 mmHg) within 24 h of ICU admission in the Critical Medicine Department of Peking Union Medical College Hospital. Patients were classified into two groups based on the LVSV changes after negative fluid balance. The cutoff value was 10%. The hemodynamic and echo parameters of the two groups were recorded at baseline and after negative fluid balance. Results: A total of 71 patients included in this study. Forty in VI Group (LVOT VTI increased ≥10%) and 31 in VNI Group (LVOT VTI increased <10%). Of all patients, 56.3% showed increased LVSV after negative fluid balance. In terms of hemodynamic parameters at T0, patients in VI Group had a higher CVP (p < 0.001) and P(v-a)CO₂ (p < 0.001) and lower ScVO₂ (p < 0.001) relative to VNI Group, regarding the echo parameters at T0, the RV_D/LV_D ratio (p < 0.001), DIVC _{end-expiratory} (p < 0.001), and ΔLVOT VTI (p < 0.001) were higher, while T0 LVOT VTI (p < 0.001) was lower, in VI Group patients. The multifactor logistic regression analysis suggested that a high CVP and RV_D/LV_D ratio ≥0.6 were significant associated with LVSV increase after negative fluid balance in critically patients. The AUC of CVP was 0.894. A CVP >10.5 mmHg provided a sensitivity of 87.5% and a specificity of 77.4%. The AUC of CVP combined with the RV_D/LV_D ratio ≥0.6 was 0.926, which provided a sensitivity of 92.6% and a specificity of 80.4%. Conclusion: High CVP and RV_D/LV_D ratio ≥0.6 were significant associated with RV stressed in critically patients. Negative fluid balance will not always lead to a decrease, even an increase, in LVSV in these patients.

Impact of Preload on Right Ventricular Hemodynamics in Acute Pulmonary Embolism

OBJECTIVES

To compare the hemodynamic effects of increased versus decreased preload in a porcine model of acute intermediate-risk pulmonary embolism.

DESIGN

Randomized, controlled animal study.

SETTING

Tertiary medical center, animal research laboratory.

SUBJECTS

Female, Danish slaughter pigs (n = 22, ~ 60 kg).

INTERVENTIONS

Acute pulmonary embolism was induced by large emboli made from clotting of autologous blood. Sixteen animals were randomized to either fluid loading (n = 8, isotonic saline, 1 L/hr for 2 hr) or diuretic treatment (n = 8, furosemide, 40 mg every 30 min, total 160 mg) and compared with a vehicle group (n = 6, no treatment).

MEASUREMENTS AND MAIN RESULTS

Hemodynamics were evaluated at baseline, after pulmonary embolism and after each dose by biventricular pressure-volume loops, invasive pressures, diuretic output, respiratory variables, and blood analysis. Pulmonary embolism increased mean pulmonary arterial pressure (p < 0.0001), pulmonary vascular resistance (p = 0.008), right ventricular arterial elastance (p = 0.003), and right ventricular end-systolic volume (p = 0.020) while right ventricular stroke volume and right ventricular ejection fraction were decreased (p = 0.047 and p = 0.0003, respectively) compared with baseline. Fluid loading increased right ventricular end-diastolic volume (+31 ± 13 mL; p = 0.004), right ventricular stroke volume (+23 ± 10 mL; p = 0.009), cardiac output (+2,021 ± 956 mL; p = 0.002), and right ventricular ejection fraction (+7.6% ± 1.5%; p = 0.032), whereas pulmonary vascular resistance decreased (-202 ± 65 dynes; p = 0.020) compared with vehicle. Diuretic treatment decreased right ventricular end-diastolic volume (-84 ± 11 mL; p < 0.001), right ventricular stroke volume (-40 ± 6 mL; p = 0.001), cardiac output (-3,327 ± 451 mL; p = 0.005), and mean pulmonary arterial pressure (-7 ± 1 mm Hg; p < 0.001) and increased right ventricular end-systolic elastance (+0.72 ± 0.2 mm Hg/mL; p < 0.001) and systemic vascular resistance (+1,812 ± 767 dynes; p < 0.001) with no effects on mean arterial pressure.

CONCLUSIONS

In a porcine model of acute intermediate-risk pulmonary embolism, fluid loading increased right ventricular preload and right ventricular stroke volume, whereas diuretics decreased right ventricular preload and right ventricular stroke volume without affecting mean arterial pressure.

Current Controversies in Caring for the Critically Ill Pulmonary Embolism Patient

Emergency physicians must be prepared to rapidly diagnose and resuscitate patients with pulmonary embolism (PE). Certain aspects of PE resuscitation run counter to typical approaches. A specific understanding of the pathophysiology of PE is required to avoid cardiovascular collapse potentially associated with excessive intravenous fluids and positive pressure ventilation. Once PE is diagnosed, rapid risk stratification should be performed and treatment guided by patient risk class. Although anticoagulation remains the mainstay of PE treatment, emergency physicians also must understand the indications and contraindications for thrombolysis and should be aware of new therapies and models of care that may improve outcomes.

Overview of Management of Intermediate- and High-Risk Pulmonary Embolism

Anticoagulation is the cornerstone of acute pulmonary embolism (PE) therapy. Intermediate-risk (submassive) or high-risk (massive) PE patients have higher mortality than low-risk patients. It is generally accepted that high-risk PE patients should be considered for more aggressive therapy. Intermediate-risk patients can be subdivided, although more than simply categorizing the patient is required to guide therapy. Therapeutic approaches depend on a prompt, detailed evaluation, and PE response teams may help with rapid assessment and initiation of therapy. More clinical trial data are needed to guide clinicians in the management of acute intermediate- and high-risk PE patients.

Management of Right Ventricular Failure in Pulmonary Embolism

Acute right ventricular failure remains the leading cause of mortality associated with acute pulmonary embolism (PE). This article reviews the pathophysiology behind acute right ventricular failure and strategies for managing right ventricular failure in acute PE. Immediate clot reduction via systemic thrombolytics, catheter based procedures, or surgery is always advocated for unstable patients. While waiting to mobilize these resources, it often becomes necessary to support the RV with vasoactive medications. Clinicians should carefully assess volume status and use caution with volume resuscitation. Right ventricular assist devices may have an expanding role in the future.

Mechanical Circulatory Support for High-Risk Pulmonary Embolism

Temporary mechanical circulatory support (MCS) devices have a role in treating high-risk patients with pulmonary embolism with cardiogenic shock. Mechanical circulatory device selection should be made based on center experience and device-specific features. All current devices are effective in decreasing right arterial pressure and providing circulatory support of 4 to 5 L/min. The pulmonary artery pulsatility index may prove to be an unreliable method to assess right ventricular function. Careful clinical evaluation on an individual patient basis should determine the need for MCS.

Use of extracorporeal membrane oxygenation in patients with acute high-risk pulmonary embolism: a case series with literature review

Background

Although extracorporeal membrane oxygenation (ECMO) has been used for the treatment of acute high-risk pulmonary embolism (PE), there are limited reports which focus on this approach. Herein, we described our experience with ECMO in patients with acute high-risk PE.

Methods

We retrospectively reviewed medical records of patients diagnosed with acute high-risk PE and treated with ECMO between January 2014 and December 2018.

Results

Among 16 patients included, median age was 51 years (interquartile range [IQR], 38 to 71 years) and six (37.5%) were male. Cardiac arrest was occurred in 12 (75.0%) including two cases of out-of-hospital arrest. All patients underwent veno-arterial ECMO and median ECMO duration was 1.5 days (IQR, 0.0 to 4.5 days). Systemic thrombolysis and surgical embolectomy were performed in seven (43.8%) and nine (56.3%) patients, respectively including three patients (18.8%) received both treatments. Overall 30-day mortality rate was 43.8% (95% confidence interval, 23.1% to 66.8%) and 30-day mortality rates according to the treatment groups were ECMO alone (33.3%, n=3), ECMO with thrombolysis (50.0%, n=4) and ECMO with embolectomy (44.4%, n=9).

Conclusions

Despite the vigorous treatment efforts, patients with acute high-risk PE were related to substantial morbidity and mortality. We report our experience of ECMO as rescue therapy for refractory shock or cardiac arrest in patients with PE.

The Right Ventricle During Selective Lung Ventilation for Thoracic Surgery

The right ventricle (RV) has been an area of evolving interest after decades of being ignored and considered less important than the left ventricle. Right ventricular dysfunction/failure is an independent predictor of mortality and morbidity in cardiac surgery; however, very little is known about the incidence or impact of RV dysfunction/failure in thoracic surgery. The pathophysiology of RV dysfunction/failure has been studied in the context of acute respiratory distress syndrome (ARDS), cardiac surgery, pulmonary hypertension, and left ventricular failure, but limited data exist in literature addressing the issue of RV dysfunction/failure in the context of thoracic surgery and one-lung ventilation (OLV). Thoracic surgery and OLV present as a unique situation where the RV is faced with sudden changes in afterload, preload, and contractility throughout the perioperative period. The authors discuss the possible pathophysiologic mechanisms that can affect adversely the RV during OLV and introduce the term RV injury to the myocardium that is affected adversely by the various intraoperative factors, which then makes it predisposed to acute dysfunction. The most important of these mechanisms seems to be the role of intraoperative mechanical ventilation, which potentially could cause both ventilator-induced lung injury leading to ARDS and RV injury. Identification of at-risk patients in the perioperative period using focused imaging, particularly echocardiography, is paramount. The authors also discuss the various RV-protective strategies required to prevent RV dysfunction and management of established RV failure.

Surgical embolectomy for acute massive pulmonary embolism: state of the art

Massive pulmonary embolism (PE) is a severe condition that can potentially lead to death caused by right ventricular (RV) failure and the consequent cardiogenic shock. Despite the fact thrombolysis is often administrated to critical patients to increase pulmonary perfusion and to reduce RV afterload, surgical treatment represents another valid option in case of failure or contraindications to thrombolytic therapy. Correct risk stratification and multidisciplinary proactive teams are critical factors to dramatically decrease the mortality of this global health burden. In fact, the worldwide incidence of PE is 60-70 per 100,000, with a mortality ranging from 1% for small PE to 65% for massive PE. This review provides an overview of the diagnosis and management of this highly lethal pathology, with a focus on the surgical approaches at the state of the art.

Prise en charge de l'embolie pulmonaire grave en réanimation

L'embolie pulmonaire (EP) grave, définie par la présence d’un état de choc, est à l'origine d'une mortalité importante. L'objectif de cette mise au point est de synthétiser les dernières avancées et recommandations concernant la prise en charge des formes graves d'EP. La stratification du risque individuel de mortalité précoce permet d'apporter une stratégie diagnostique et thérapeutique optimisée pour chaque patient. Le traitement symptomatique consiste essentiellement en la prise en charge de l'état de choc. L'anticoagulation curative par héparine non fractionnée est réservée aux patients hémodynamiquement instables. Chez ces patients à haut risque, la thrombolyse systémique diminue la mortalité et le risque de récidive d'EP. Chez les patients à risque intermédiaire élevé, la thrombolyse systémique à dose standard diminue le risque de choc secondaire mais sans impact sur la mortalité globale. La thrombolyse est donc réservée aux patients à risque intermédiaire élevé présentant secondairement un état de choc. L'embolectomie chirurgicale reste indiquée en cas de contre-indication absolue à la thrombolyse ou en cas d'échec de celle-ci. Le positionnement dans l'algorithme thérapeutique de l'assistance extracorporelle et des techniques percutanées de revascularisation reste à définir. Leurs indications doivent donc être discutées dans des centres experts après une concertation multidisciplinaire incluant pneumologues, cardiologues, réanimateurs, radiologues interventionnels et chirurgiens cardiaques.

Diagnostic workup, etiologies and management of acute right ventricle failure : A state-of-the-art paper

INTRODUCTION

This is a state-of-the-art article of the diagnostic process, etiologies and management of acute right ventricular (RV) failure in critically ill patients. It is based on a large review of previously published articles in the field, as well as the expertise of the authors.

RESULTS

The authors propose the ten key points and directions for future research in the field. RV failure (RVF) is frequent in the ICU, magnified by the frequent need for positive pressure ventilation. While no universal definition of RVF is accepted, we propose that RVF may be defined as a state in which the right ventricle is unable to meet the demands for blood flow without excessive use of the Frank-Starling mechanism (i.e. increase in stroke volume associated with increased preload). Both echocardiography and hemodynamic monitoring play a central role in the evaluation of RVF in the ICU. Management of RVF includes treatment of the causes, respiratory optimization and hemodynamic support. The administration of fluids is potentially deleterious and unlikely to lead to improvement in cardiac output in the majority of cases. Vasopressors are needed in the setting of shock to restore the systemic pressure and avoid RV ischemia; inotropic drug or inodilator therapies may also be needed. In the most severe cases, recent mechanical circulatory support devices are proposed to unload the RV and improve organ perfusion CONCLUSION: RV function evaluation is key in the critically-ill patients for hemodynamic management, as fluid optimization, vasopressor strategy and respiratory support. RV failure may be diagnosed by the association of different devices and parameters, while echocardiography is crucial.

Assessment of the effects of inspiratory load on right ventricular function

PURPOSE OF REVIEW

The right ventricle (RV) plays a pivotal role during respiratory failure because of its high sensitivity to small loading changes during inspiration. Both RVs, preload and afterload, are altered during inspiration, either in spontaneous breathing or during mechanical ventilation. Some clinical situations especially affect RV load during inspiration, for example acute asthma and acute respiratory distress syndrome. The aim of this review is to explain and to summarize the different mechanisms leading to RV failure in these situations.

RECENT FINDINGS

Research has recently reemphasized the importance to well known physiology of the venous return which is a contributor of RV preload. Authors recently focused on the mean systemic filling pressure which is one of the determinants of venous return. Venous return may change in opposite direction according to the type of ventilation (spontaneous or assisted). Recent works have also demonstrated the crucial impact of lung inflation and driving pressure on RV afterload, and have confirmed the deleterious effect of severe RV failure, described as acute cor pulmonale. In most situations of RV overload induced by inspiration, significant pulse pressure variations are observed, either called 'pulsus paradoxus' in spontaneously breathing patients or 'reverse pulsus paradoxus' in mechanically ventilated patients.

SUMMARY

RV is very sensitive to abnormal inspiration, which is always responsible for an increase in its afterload. Pulse pressure variations, central venous pressure and especially echocardiography may monitor RV function in abnormal clinical situations. The pulmonary artery catheter was also proposed although now less used.

Management of patients with high-risk pulmonary embolism: a narrative review

High-risk pulmonary embolism (PE) is a life-threatening disorder associated with high mortality and morbidity. Most deaths in patients with shock occur within the first few hours after presentation, and rapid diagnosis and treatment is therefore essential to save patients’ lives. The main manifestations of major PE are acute right ventricular (RV) failure and hypoxia. RV pressure overload is predominantly related to the interaction between the mechanical pulmonary vascular obstruction and the underlying cardiopulmonary status. Computed tomography angiography allows not only adequate visualization of the pulmonary thromboemboli down to at least the segmental level but also RV enlargement as an indicator of RV dysfunction. Bedside echocardiography is an acceptable alternative under such circumstances. Although it does not usually provide a definitive diagnosis or exclude pulmonary embolism, echocardiography can confirm or exclude severe RV pressure overload and dysfunction. Extracorporeal membrane oxygenation support can be an effective procedure in patients with PE-induced circulatory collapse. Thrombolysis is generally accepted in unstable patients with high-risk PE; however, thrombolytic agents cannot be fully administered to patients with a high risk of bleeding. Conversely, catheter-directed treatment is an optimal treatment strategy for patients with high-risk PE who have contraindications for thrombolysis and is a minimally invasive alternative to surgical embolectomy. It can be performed with a minimum dose of thrombolytic agents or without, and it can be combined with various procedures including catheter fragmentation or embolectomy in accordance with the extent of the thrombus on a pulmonary angiogram. Hybrid catheter-directed treatment can reduce a rapid heart rate and high pulmonary artery pressure and can improve the gas exchange indices and outcomes. Surgical embolectomy is also performed in patients with contraindications for or an inadequate response to thrombolysis. Large hospitals having an intensive care unit should preemptively establish diagnostic and therapeutic protocols and rehearse multidisciplinary management for patients with high-risk PE. Coordination with a skilled team comprising intensivists, cardiologists, cardiac surgeons, radiologists, and other specialists is crucial to maximize success.

Hospital and intensive care unit management of decompensated pulmonary hypertension and right ventricular failure

Pulmonary hypertension and concomitant right ventricular failure present a diagnostic and therapeutic challenge in the intensive care unit and have been associated with a high mortality. Significant co-morbidities and hemodynamic instability are often present, and routine critical care unit resuscitation may worsen hemodynamics and limit the chances of survival in patients with an already underlying poor prognosis. Right ventricular failure results from structural or functional processes that limit the right ventricle’s ability to maintain adequate cardiac output. It is commonly seen as the result of left heart failure, acute pulmonary embolism, progression or decompensation of pulmonary hypertension, sepsis, acute lung injury, or in the perioperative setting. Prompt recognition of the underlying cause and institution of treatment with a thorough understanding of the elements necessary to optimize preload, cardiac contractility, enhance systemic arterial perfusion, and reduce right ventricular afterload are of paramount importance. Moreover, the emergence of previously uncommon entities in patients with pulmonary hypertension (pregnancy, sepsis, liver disease, etc.) and the availability of modern devices to provide support pose additional challenges that must be addressed with an in-depth knowledge of this disease.

Medical Management of Pulmonary Embolism: Beyond Anticoagulation

Pulmonary embolism (PE) is a common medical condition that carries significant morbidity and mortality. Although diagnosis, anticoagulation, and interventional clot-burden reduction strategies represent the focus of clinical research and care in PE, appropriate risk stratification and supportive care are crucial to ensure good outcomes. In this chapter, we will discuss the medical management of PE from the time of presentation to discharge, focusing on the critical care of acute right ventricular failure, anticoagulation of special patient populations, and appropriate follow-up testing after acute PE.

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.

Right Ventricular Function, Peripheral Edema, and Acute Kidney Injury in Critical Illness

Introduction

The cardiorenal syndrome generally focuses on left ventricular function, and the importance of the right ventricle as a determinant of renal function is described less frequently. In a cohort of critically ill patients with echocardiographic measurements obtained within 24 hours of admission to the intensive care unit, we examined the association of right ventricular function with acute kidney injury (AKI) and AKI-associated mortality. We also examined whether clinical measurement of volume overload modified the association between ventricular function and AKI in a subpopulation with documented admission physical examinations.

Methods

Among 1879 critically ill patients with echocardiographic ventricular measurements, 43% (n = 807) had ventricular dysfunction—21% (n = 388), 9% (n = 167), and 13% (n = 252) with isolated left ventricular dysfunction, isolated right ventricular dysfunction, and biventricular dysfunction, respectively. Overall, ventricular dysfunction was associated with a 43% higher adjusted risk of AKI (95% confidence interval [CI] 1.14–1.80; P = 0.002) compared with those with normal biventricular function, whereas isolated left ventricular dysfunction, isolated right ventricular dysfunction, and biventricular dysfunction were associated with a 1.34 (95% CI 1.00-1.77, P = 0.05), 1.35 (95% CI 0.90–2.10, P = 0.14) and 1.67 (95% CI 1.23–2.31, P = 0.002) higher adjusted risk. Although an episode of AKI was associated with an approximately 2-fold greater risk of hospital mortality in those with isolated left ventricular dysfunction and biventricular dysfunction, in those with isolated right ventricular dysfunction, AKI was associated with a 7.85-fold greater risk of death (95% CI 2.89–21.3, P < 0.001). Independent of ventricular function, peripheral edema was an important determinant of AKI.

Discussion

Like left ventricular function, right ventricular function is an important determinant of AKI and AKI-associated mortality. Volume overload, independently of ventricular function, is a risk factor for AKI. Whether establishment of euvolemia might mitigate AKI risk will require further study.

The use of veno-venous extracorporeal membrane oxygenation following thrombolysis for massive pulmonary embolism

A 59-year-old man was diagnosed with a massive pulmonary embolism. Despite thrombolysis there were two episodes of cardiac arrest and following recovery of spontaneous circulation profound cardiorespiratory failure ensued. An extracorporeal membrane oxygenation retrieval team initiated veno-venous extracorporeal membrane oxygenation on site to facilitate transfer to the extracorporeal membrane oxygenation centre. An excellent outcome is reported in the short term. This represents one of the few published cases of veno-venous extracorporeal membrane oxygenation for a massive pulmonary embolism following thrombolysis.

[Pulmonary embolism]

Pulmonary embolism is a potentially fatal disorder and frequently seen in critical care and emergency medicine. Due to a high mortality rate within the first few hours, the accurate initiation of rational diagnostic pathways in patients with suspected pulmonary embolism and timely consecutive treatment is essential. In this review, the current European guidelines on the diagnosis and therapy of acute pulmonary embolism are presented. Special focus is put on a structured patient management based on the individual risk of early mortality. In particular risk assessment and new risk-adjusted treatment recommendations are presented and discussed in this article.

The Right Ventricle in ARDS

ARDS is associated with poor clinical outcomes, with a pooled mortality rate of approximately 40% despite best standards of care. Current therapeutic strategies are based on improving oxygenation and pulmonary compliance while minimizing ventilator-induced lung injury. It has been demonstrated that relative hypoxemia can be well tolerated, and improvements in oxygenation do not necessarily translate into survival benefit. Cardiac failure, in particular right ventricular dysfunction (RVD), is commonly encountered in moderate to severe ARDS and is reported to be one of the major determinants of mortality. The prevalence rate of echocardiographically evident RVD in ARDS varies across studies, ranging from 22% to 50%. Although there is no definitive causal relationship between RVD and mortality, severe RVD is associated with increased mortality. Factors that can adversely affect RV function include hypoxic pulmonary vasoconstriction, hypercapnia, and invasive ventilation with high driving pressure. It might be expected that early diagnosis of RVD would be of benefit; however, echocardiographic markers (qualitative and quantitative) used to prospectively evaluate the right ventricle in ARDS have not been tested in adequately powered studies. In this review, we examine the prognostic implications and pathophysiology of RVD in ARDS and discuss available diagnostic modalities and treatment options. We aim to identify gaps in knowledge and directions for future research that could potentially improve clinical outcomes in this patient population.

Acute respiratory distress syndrome: the heart side of the moon

PURPOSE OF REVIEW

Circulatory failure is a frequent complication during acute respiratory distress syndrome (ARDS) and is associated with a poor outcome. This review aims at clarifying the mechanisms of circulatory failure during ARDS.

RECENT FINDINGS

For the past decades, the right ventricle (RV) has gained a crucial interest since many authors confirmed the high incidence of acute cor pulmonale during ARDS and showed a potential role of the acute cor pulmonale in the poor outcome of ARDS patients. The most important recent progress demonstrated in ARDS ventilatory strategy is represented by the prone position, which has a huge beneficial effect on RV afterload. This review will focus on the mechanisms responsible for the RV dysfunction/failure during ARDS and on the strategy, which allows improving the right ventricular function.

SUMMARY

The RV has a pivotal role in the circulatory failure of ARDS patients. The ventilatory strategy during ARDS has to pay a peculiar attention to the RV to rigorously control its afterload.

Predicting and measuring fluid responsiveness with echocardiography

Echocardiography is ideally suited to guide fluid resuscitation in critically ill patients. It can be used to assess fluid responsiveness by looking at the left ventricle, aortic outflow, inferior vena cava and right ventricle. Static measurements and dynamic variables based on heart–lung interactions all combine to predict and measure fluid responsiveness and assess response to intravenous fluid resuscitation. Thorough knowledge of these variables, the physiology behind them and the pitfalls in their use allows the echocardiographer to confidently assess these patients and in combination with clinical judgement manage them appropriately.

Prognostic Value of Renal Dysfunction Indicators in Normotensive Patients With Acute Pulmonary Embolism

Introduction:

Glomerular filtration rate (GFR) and blood urea nitrogen (BUN) are important prognostic indicators for cardiovascular disease. However, data on the relationship between renal dysfunction (RD) and prognosis in patients with acute pulmonary embolism (APE) are limited. The estimated-GFR (eGFR), based on the Modification of Diet in Renal Disease (MDRD) equation, has been suggested as a possible prognostic marker in patients with APE; however, at present, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation is thought to be more accurate than the MDRD equation for the estimation of RD.

Objective:

We investigated whether eGFRCKD-EPI or BUN could predict adverse outcomes (AOs) better than eGFRMDRD in normotensive patients with APE.

Methods:

Ninety-nine normotensive patients with APE (aged 22-96, 56% male) were enrolled in the study retrospectively. Adverse outcomes were defined as the occurrence of any of the following: death, cardiopulmonary resuscitation, use of vasopressors, thrombolysis, or mechanical ventilation.

Results:

In univariate analyses, age, gender (male), heart rate (>110 bpm), serum creatinine, BUN, cardiac troponin (cTn) positivity, right ventricle–left ventricle ratio, eGFRMDRD, and eGFRCKD-EPI were found to be significantly different between those with and without AOs. Comparing area under the curves for AO, we found statistically significant differences between eGFRCKD-EPI and eGFRMDRD ( P = .01) but not between BUN and eGFRCKD-EPI or BUN and eGFRMDRD. Furthermore, 30-day mortality was 36% versus 11% in cTn-positive patients with an eGFRCKD-EPI < and ≥ 60 mL/min, respectively.

Conclusion:

There is a close relationship between RD and APE prognosis. We conclude eGFRCKD-EPI is a potential prognostic marker for risk stratification in normotensive patients with APE.

Recent advances in the management of pulmonary embolism: focus on the critically ill patients

The aim of this narrative review is to summarize for intensivists or any physicians managing “severe” pulmonary embolism (PE) the main recent advances or recommendations in the care of patients including risk stratification, diagnostic algorithm, hemodynamic management in the intensive care unit (ICU), recent data regarding the use of thrombolytic treatment and retrievable vena cava filters and finally results of direct oral anticoagulants. Thanks to the improvements achieved in the risk stratification of patients with PE, a better therapeutic approach is now recommended from diagnosis algorithm and indication to admission in ICU to indication of thrombolysis and general hemodynamic support in patients with shock. Given at current dosage, thrombolytic therapy is associated with a reduction in the combined end-point of mortality and hemodynamic decompensation in patients with intermediate-risk PE, but this is obtained without a decrease in overall mortality and with a significant increase in major extracranial and intracranial bleeding. In patients with high-intermediate-risk PE, thrombolytic therapy should be given in case of hemodynamic worsening. Vena cava filters are of little help when anticoagulant treatment is not contraindicated, even in patients with PE and features of clinical severity. Finally, direct oral anticoagulants have been shown to be as effective as and safer than the combination of low molecular weight heparin and vitamin K antagonist(s) in patients with venous thromboembolism and low- to intermediate-risk PE.