High-risk pulmonary embolism in the intensive care unit

Management of high-risk acute pulmonary embolism: an emulated target trial analysis

BACKGROUND

High-risk acute pulmonary embolism (PE) is a life-threatening condition necessitating hemodynamic stabilization and rapid restoration of pulmonary perfusion. In this context, evidence regarding the benefit of advanced circulatory support and pulmonary recanalization strategies is still limited.

METHODS

In this observational study, we assessed data of 1060 patients treated for high-risk acute PE with 991 being included in a target trial emulation to investigate all-cause in-hospital mortality estimates with different advanced treatment strategies. The four treatment groups consisted of patients undergoing (I) veno-arterial extracorporeal membrane oxygenation (VA-ECMO) alone (n = 126), (II) intrahospital systemic thrombolysis (SYS) (n = 643), (III) surgical thrombectomy (ST) (n = 49), and (IV) percutaneous catheter-directed treatment (PCDT) (n = 173). VA-ECMO was allowed as bridging to pulmonary recanalization in groups II, III, and IV. Marginal causal contrasts were estimated using the g-formula with logistic regression models as the primary approach. Sensitivity analyses included targeted maximum likelihood estimation (TMLE) with machine learning, inverse probability of treatment weighting (IPTW), as well as variations of estimands, handling of missing values, and a complete target trial emulation excluding the VA-ECMO alone group.

RESULTS

In the overall target trial population, the median age was 62.0 years, and 53.3% of patients were male. The estimated probability of in-hospital mortality from the primary target trial intention-to-treat analysis for VA-ECMO alone was 57% (95% confidence interval [CI] 47%; 67%), compared to 48% (95% CI 44%; 53%) for intrahospital SYS, 34% (95%CI 18%; 50%) for ST, and 43% (95% CI 35%; 51%) for PCDT. The mortality risk ratios were largely in favor of any advanced recanalization strategy over VA-ECMO alone. The robustness of these findings was supported by all sensitivity analyses. In the crude outcome analysis, patients surviving to discharge had a high probability of favorable neurologic outcome in all treatment groups.

CONCLUSION

Advanced recanalization by means of SYS, ST, and several promising catheter-directed systems may have a positive impact on short-term survival of patients presenting with high-risk PE compared to the use of VA-ECMO alone as a bridge to recovery.

The Five Pillars of Acute Right Ventricular Heart Failure Therapy: Can We Keep the Pediment in Balance?

Acute right ventricular heart failure (aRHF), a long-neglected aspect of heart disease, has recently gained attention due to an improved understanding of its pathophysiology and the development of tailored therapeutic strategies. The therapeutic approach is now built on several pillars that aim to support the stable clinical condition of the patient, starting with the central pillar of etiological or specific therapy and extending to various aspects related to hemodynamic support, ventilation support, fluid optimization, and, when necessary, advanced resources such as right ventricular assist devices (e.g., extracorporeal membrane oxygenation-ECMO, Impella RP, or ProtekDuo). This five-pillar approach summarizes the different facets of contemporary treatment for aRHF, although some aspects related to their use are still being clarified.

Pulmonary Embolism in Critically Ill Patients-Prevention, Diagnosis, and Management

Critically ill patients in the intensive care unit (ICU) are often immobilized and on mechanical ventilation, placing them at increased risk for thromboembolic diseases, particularly deep vein thrombosis (DVT) and, to a lesser extent, pulmonary embolism (PE). While these conditions are frequently encountered in the emergency department, managing them in the ICU presents unique challenges. Although existing guidelines are comprehensive and effective, they are primarily designed for patients presenting with PE in the emergency department and do not fully address the complexities of managing critically ill patients in the ICU. This review aims to summarize the available data on these challenging cases, offering a practical approach to the prevention, diagnosis, and treatment of PE, particularly when it is acquired in the ICU.

Severe Traumatic Brain Injury and Pulmonary Embolism: Risks, Prevention, Diagnosis and Management

Severe traumatic brain injury (sTBI) is a silent epidemic, causing approximately 300,000 intensive care unit (ICU) admissions annually, with a 30% mortality rate. Despite worldwide efforts to optimize the management of patients and improve outcomes, the level of evidence for the treatment of these patients remains low. The concomitant occurrence of thromboembolic events, particularly pulmonary embolism (PE), remains a challenge for intensivists due to the risks of anticoagulation to the injured brain. We performed a literature review on sTBI and concomitant PE to identify and report the most recent advances on this topic. We searched PubMed and Scopus for papers published in the last five years that included the terms "pulmonary embolism" and "traumatic brain injury" in their title or abstract. Exclusion criteria were papers referring to children, non-sTBI populations, and post-acute care. Our search revealed 75 papers, of which 38 are included in this review. The main topics covered include the prevalence of and risk factors for pulmonary embolism, the challenges of timely diagnosis in the ICU, the timing of pharmacological prophylaxis, and the treatment of diagnosed PE.

Blood urea nitrogen to creatinine ratio is associated with in-hospital mortality in critically ill patients with venous thromboembolism: a retrospective cohort study

Background

The relationship between the blood urea nitrogen to creatinine ratio (BCR) and the risk of in-hospital mortality among intensive care unit (ICU) patients diagnosed with venous thromboembolism (VTE) remains unclear. This study aimed to assess the relationship between BCR upon admission to the ICU and in-hospital mortality in critically ill patients with VTE.

Methods

This retrospective cohort study included patients diagnosed with VTE from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The primary endpoint was in-hospital mortality. Univariate and multivariate logistic regression analyses were conducted to evaluate the prognostic significance of the BCR. Receiver operating characteristic (ROC) curve analysis was utilized to determine the optimal cut-off value of BCR. Additionally, survival analysis using a Kaplan-Meier curve was performed.

Results

A total of 2,560 patients were included, with a median age of 64.5 years, and 55.5% were male. Overall, the in-hospital mortality rate was 14.6%. The optimal cut-off value of the BCR for predicting in-hospital mortality in critically ill VTE patients was 26.84. The rate of in-hospital mortality among patients categorized in the high BCR group was significantly higher compared to those in the low BCR group (22.6% vs. 12.2%, P < 0.001). The multivariable logistic regression analysis results indicated that, even after accounting for potential confounding factors, patients with elevated BCR demonstrated a notably increased in-hospital mortality rate compared to those with lower BCR levels (all P < 0.05), regardless of the model used. Patients in the high BCR group exhibited a 77.77% higher risk of in-hospital mortality than those in the low BCR group [hazard ratio (HR): 1.7777; 95% CI: 1.4016-2.2547].

Conclusion

An elevated BCR level was independently linked with an increased risk of in-hospital mortality among critically ill patients diagnosed with VTE. Given its widespread availability and ease of measurement, BCR could be a valuable tool for risk stratification and prognostic prediction in VTE patients.

Intensive Care Treatment of Pulmonary Embolism: An Update Based on the Revised AWMF S2k Guideline

Acute pulmonary embolism (PE) remains a significant cause of morbidity and requires prompt diagnosis and management. The prognosis of affected patients depends on the clinical severity. Therefore, risk stratification is imperative for therapeutic decision-making. Patients with high-risk PE need intensive care. These include patients who have successfully survived resuscitation, with obstructive shock or persistent haemodynamic instability. Bedside diagnostics by means of sonographic procedures are of outstanding importance in this high-risk population. In addition to the treatment of hypoxaemia with noninvasive and invasive techniques, the focus is on drug-based haemodynamic stabilisation and usually requires the elimination or reduction of pulmonary vascular thrombotic obstruction by thrombolysis. In the event of a contraindication to thrombolysis or failure of thrombolysis, various catheter-based procedures for thrombus extraction and local thrombolysis are available today and represent an increasing alternative to surgical embolectomy. Mechanical circulatory support systems can bridge the gap between circulatory arrest or refractory shock and definitive stabilisation but are reserved for centres with the appropriate expertise. Therapeutic strategies for patients with intermediate- to high-risk PE in terms of reduced-dose thrombolytic therapy or catheter-based procedures need to be further evaluated in prospective clinical trials.

Bedside electrical impedance tomography to assist the management of pulmonary embolism: A case report

Background

Pulmonary embolism (PE) is a common worldwide disease with high mortality. Timely diagnosis and management of PE could significantly improve clinical outcomes. Electrical impedance tomography (EIT) is a novel noninvasive technique to monitor lung perfusion and help detect PE at the bedside. Here we present a case of clinical management of subsegmental PE with the help of the bilateral ventilation and perfusion(V/Q) asymmetry EIT image.

Case presentation

A 72-year-old cancer patient with respiratory failure and acute kidney injury in the intensive care unit was suspected of PE based on his clinical manifestation. The contraindication of computed tomography pulmonary angiography (CTPA) for PE diagnosis prevented escalating anticoagulation therapy. Besides EIT ventilation and perfusion monitoring showed an abnormal asymmetry V/Q match between the bilateral lungs which promoted our decision to start systemic continuous anticoagulation therapy and improved the patient clinically. The following CTPA which clarified the diagnosis of PE suggests that the patient has benefited from our decision.

Conclusion

For critically ill patients with suspected PE, the asymmetry of the EIT V/Q image may provide crucial objective information for clinical management.

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.

Venous thromboembolism in critically ill adult patients with hematologic malignancy: a population-based cohort study

PURPOSE

The aim of this study was to describe the incidence of venous thromboembolism (VTE) and major bleeding among hospitalized patients with hematologic malignancy, assessing its association with critical illness and other baseline characteristics.

METHODS

We conducted a population-based cohort study of hospitalized adults with a new diagnosis of hematologic malignancy in Ontario, Canada, between 2006 and 2017. The primary outcome was VTE (pulmonary embolism or deep venous thrombosis). Secondary outcomes were major bleeding and in-hospital mortality. We compared the incidence of VTE between intensive care unit (ICU) and non-ICU patients and described the association of other baseline characteristics and VTE.

RESULTS

Among 76,803 eligible patients (mean age 67 years [standard deviation, SD, 15]), 20,524 had at least one ICU admission. The incidence of VTE was 3.7% in ICU patients compared to 1.2% in non-ICU patients (odds ratio [OR] 3.08; 95% confidence interval [CI] 2.77-3.42). The incidence of major bleeding was 7.6% and 2.4% (OR 3.33; 95% CI 3.09-3.58), respectively. The association of critical illness and VTE remained significant after adjusting for potential confounders (OR 2.92; 95% CI 2.62-3.25). We observed a higher incidence of VTE among specific subtypes of hematologic malignancy and patients with prior VTE (OR 6.64; 95% CI 5.42-8.14). Admission more than 1 year after diagnosis of hematologic malignancy (OR 0.64; 95% CI 0.56-0.74) and platelet count ≤ 50 × 109/L at the time of hospitalization (OR 0.63; 95% CI 0.48-0.84) were associated with a lower incidence of VTE.

CONCLUSION

Among patients with hematologic malignancy, critical illness and certain baseline characteristics were associated with a higher incidence of VTE.

MACHINE LEARNING FOR PREDICTING HEMODYNAMIC DETERIORATION OF PATIENTS WITH INTERMEDIATE-RISK PULMONARY EMBOLISM IN INTENSIVE CARE UNIT

ABSTRACT

Background: Intermediate-risk pulmonary embolism (PE) patients in the intensive care unit (ICU) are at a higher risk of hemodynamic deterioration than those in the general ward. This study aimed to construct a machine learning (ML) model to accurately identify the tendency for hemodynamic deterioration in the ICU patients with intermediate-risk PE. Method: A total of 704 intermediate-risk PE patients from the MIMIC-IV database were retrospectively collected. The primary outcome was defined as hemodynamic deterioration occurring within 30 days after admission to ICU. Four ML algorithms were used to construct models on the basis of all variables from MIMIC IV database with missing values less than 20%. The extreme gradient boosting (XGBoost) model was further simplified for clinical application. The performance of the ML models was evaluated by using the receiver operating characteristic curve, calibration plots, and decision curve analysis. Predictive performance of simplified XGBoost was compared with the simplified Pulmonary Embolism Severity Index score. SHapley Additive explanation (SHAP) was performed on a simplified XGBoost model to calculate the contribution and impact of each feature on the predicted outcome and presents it visually. Results: Among the 704 intermediate-risk PE patients included in this study, 120 patients experienced hemodynamic deterioration within 30 days after admission to the ICU. Simplified XGBoost model demonstrated the best predictive performance with an area under the curve of 0.866 (95% confidence interval, 0.800-0.925), and after recalibrated by isotonic regression, the area under the curve improved to 0.885 (95% confidence interval, 0.822-0.935). Based on the simplified XGBoost model, a web app was developed to identify the tendency for hemodynamic deterioration in ICU patients with intermediate-risk PE. Conclusion: A simplified XGBoost model can accurately predict the occurrence of hemodynamic deterioration for intermediate-risk PE patients in the ICU, assisting clinical workers in providing more personalized management for PE patients in the ICU.