Bedside echocardiographic evaluation of hemodynamics in sepsis: is a qualitative evaluation sufficient?

Septic Cardiomyopathy: Difficult Definition, Challenging Diagnosis, Unclear Treatment

Sepsis is a systemic inflammatory response syndrome of suspected or confirmed infectious origin, which frequently culminates in multiorgan failure, including cardiac involvement. Septic cardiomyopathy (SCM) remains a poorly defined clinical entity, lacking a formal or consensus definition and representing a significant knowledge gap in critical care medicine. It is an often-underdiagnosed complication of sepsis. The only widely accepted aspect of its definition is that SCM is a transient myocardial dysfunction occurring in patients with sepsis, which cannot be attributed to ischemia or pre-existing cardiac disease. The pathogenesis of SCM appears to be multifactorial, involving inflammatory cytokines, overproduction of nitric oxide, mitochondrial dysfunction, calcium homeostasis dysregulation, autonomic imbalance, and myocardial edema. Diagnosis primarily relies on echocardiography, with advanced tools such as tissue Doppler imaging (TDI) and global longitudinal strain (GLS) providing greater sensitivity for detecting subclinical dysfunction and guiding therapeutic decisions. Traditional echocardiographic findings, such as left ventricular ejection fraction measured by 2D echocardiography, often reflect systemic vasoplegia rather than intrinsic myocardial dysfunction, complicating accurate diagnosis. Right ventricular (RV) dysfunction, identified as a critical component of SCM in many studies, has multifactorial pathophysiology. Factors including septic cardiomyopathy itself, mechanical ventilation, hypoxemia, and hypercapnia-particularly in cases complicated by acute respiratory distress syndrome (ARDS)-increase RV afterload and exacerbate RV dysfunction. The prognostic value of cardiac biomarkers, such as troponins and natriuretic peptides, remains uncertain, as these markers primarily reflect illness severity rather than being specific to SCM. Treatment focuses on the early recognition of sepsis, hemodynamic optimization, and etiological interventions, as no targeted therapies currently exist. Emerging therapies, such as levosimendan and VA-ECMO, show potential in severe SCM cases, though further validation is needed. The lack of standardized diagnostic criteria, combined with the heterogeneity of sepsis presentations, poses significant challenges to the effective management of SCM. Future research should focus on developing cluster-based classification systems for septic shock patients by integrating biomarkers, echocardiographic findings, and clinical parameters. These advancements could clarify the underlying pathophysiology and enable tailored therapeutic strategies to improve outcomes for SCM patients.

Cardiac Resolvin D2 ameliorates sepsis-induced cardiomyopathy via inhibiting Caspase-11/GSDMD dependent pyroptosis

BACKGROUND

Sepsis-induced cardiomyopathy (SICM) is common complication in septic patients with a high mortality and is characterized by an abnormal inflammation response, which was precisely regulated by endogenous specialized pro-resolving mediators (SPMs). However, the metabolic changes of cardiac SPMs during SICM and the roles of SPMs subset in the development of SICM remain unknown.

METHODS

In this work, the SPMs concentration was assessed using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) of SICM mice and SICM patients. The cardiac function was measured by echocardiography after the treatment of a SPMs subset, termed Resolvin D2 (RvD2). Caspase-11-/-, GSDMD-/- and double deficient (Caspase-11-/-GSDMD-/-) mice were used to clarify the mechanisms of RvD2 in SICM.

RESULTS

We found that endogenous cardiac SPMs were disorders and RvD2 was decreased significantly and correlated with left ventricular ejection fraction (LVEF) and β-BNP, cTnT in Lipopolysaccharide/Cecum ligation and puncture (CLP) induced SICM models. Treatment with RvD2 attenuated lethality, cardiac dysfunction and cardiomyocytes death during SICM. Mechanistically, RvD2 alleviated SICM via inhibiting Caspase-11/GSDMD-mediated cardiomyocytes pyroptosis. Finally, the plasma levels of RvD2 were also decreased and significantly correlated with IL-1β, β-BNP, cTnT and LVEF in patients with SICM. Of note, plasma RvD2 level is indicator of SICM patients from healthy controls or sepsis patients.

CONCLUSION

These findings suggest that decreased cardiac RvD2 may involve in the pathogenesis of SICM. In addition, treatment with RvD2 represents a novel therapeutic strategy for SICM by inhibiting cardiomyocytes pyroptosis.

MEAN ARTERIAL PRESSURE/NOREPINEPHRINE EQUIVALENT DOSE INDEX AS AN EARLY MEASURE FOR MORTALITY RISK IN PATIENTS WITH SHOCK ON VASOPRESSORS

ABSTRACT

Purpose: We aimed to investigate the association between the early mean arterial pressure (MAP)/norepinephrine equivalent dose (NEQ) index and mortality risk in patients with shock on vasopressors and further identify the breakpoint value of the MAP/NEQ index for high mortality risk. Methods: Based on the Medical Information Mart for Intensive Care IV database, we conducted a retrospective cohort study involving 19,539 eligible intensive care unit records assigned to three groups (first tertile, second tertile, and third tertile) by different MAP/NEQ indexes within 24 h of intensive care unit admission. The study outcomes were 7-, 14-, 21-, and 28-day mortality. A Cox model was used to examine the risk of mortality following different MAP/NEQ indexes. The receiving operating characteristic curve was used to evaluate the predictive ability of the MAP/NEQ index. The restricted cubic spline was applied to fit the flexible correlation between the MAP/NEQ index and risk of mortality, and segmented regression was further used to identify the breakpoint value of the MAP/NEQ index for high mortality risk. Results: Multivariate Cox analysis showed that a high MAP/NEQ index was independently associated with decreased mortality risks. The areas under the receiving operating characteristic curve of the MAP/NEQ index for different mortality outcomes were nearly 0.7. The MAP/NEQ index showed an L-shaped association with mortality outcomes or mortality risks. Exploration of the breakpoint value of the MAP/NEQ index suggested that a MAP/NEQ index less than 183 might be associated with a significantly increased mortality risk. Conclusions: An early low MAP/NEQ index was indicative of poor prognosis in patients with shock on vasopressors.

Echocardiographic hemodynamic assessment in decompensated cirrhosis: comparison between Intensivists and Gastroenterologists

BACKGROUND & AIMS

Ascites is a frequent complication of cirrhosis. In intensive care units, initial hemodynamic assessment is frequently performed by echocardiography. This study evaluated the feasibility and usefulness of early hemodynamic assessment in the gastroenterology ward.

METHODS

This observational cohort study prospectively included all patients admitted to a teaching hospital's gastroenterology unit for decompensated cirrhosis. A gastroenterologist with minimal training and an intensivist both performed an echocardiography exam. The primary outcome was inter-rater agreement and reliability for three echocardiography parameters: visual LVEF (Left Ventricular Ejection Fraction), subaortic VTI (velocity time integral) and E wave velocity. Secondary outcomes were agreement for presence of pleural effusion, description of 3 hemodynamics profiles (hypovolemic, hyperkinetic and intermediate), and 28-day mortality.

RESULTS

From March 2018 to March 2020, 53 patients were included. The median age was 62 years and 81% were men. Patients presented mostly advanced liver disease, with 43% Child-Pugh C and median MELD score of 15.2. The limits of agreement between intensivists and gastroenterologists for subaortic VTI were - 6.6 to 7.2 cm, and ranged from - 0.6 to 0.37 m.s-1 for E wave velocity. Clinically significant differences between intensivists and gastroenterologists were found in 22% for subaortic VTI and 24.5% for E wave velocity. Reliability was good for subaortic VTI (ICC: 0.79, 95% CI [0.58; 0.9;]) and moderate for E wave velocity (0.53, 95% CI [0.19; 0.74]). The three hemodynamics profiles had different prognosis, with a 28-day mortality for Hypovolemic, Intermediate and Hyperkinetic group of 31, 18, and 4%, respectively.

CONCLUSION

Reliability of hemodynamic assessment by gastroenterologists was good, while agreement was unsatisfactory, advocating for further training. Transthoracic echocardiography can differentiate hypovolemia from hyperkinetic states. The role of transthoracic echocardiography in managing decompensated cirrhosis requires further study.

CLINICAL TRIAL NUMBER

NCT03650660.

Echocardiographic parameters in COVID-19 patients and their association with ICU mortality: a prospective multicenter observational study

BACKGROUND

Echocardiography has become an integral part of the management of critically ill patients. It helps to diagnose and treat various conditions. COVID-19 patients can develop cardiac dysfunction. We planned to study the echocardiographic parameters in COVID-19 patients.

METHODS

We conducted a prospective observational multicenter study after institutional ethical committee approval. COVID-19 pneumonia patients admitted to the intensive care unit (ICU) were enrolled. The echocardiographic evaluation was done within 24-48 hours of admission. Assessment of the left and right heart with systolic and left ventricular diastolic function evaluation was done. The primary outcome was ICU mortality. The secondary outcomes were the length of ICU stay and duration of mechanical ventilation.

RESULTS

Among 573 patients mean age was 57.17 (14.67) with 68.60% being males. On day 1 of ICU, invasive mechanical ventilation was used in 257 (45%) patients. One hundred and forty-eight (25.83%) patients were on vasopressors when echocardiography was performed. Severe left ventricle (LV) systolic dysfunction was seen in 8.7% of patients and had higher odds of mortality [2.48(1.058-5.807), p = 0.037] followed by E and e' with odds ratio of [0.984(0.971-0.998), p = 0.021] and 0.897 (0.805-0.998), p = 0.046], respectively. E/e' indicative of filling pressure of the LV was not found to be significant. Troponin I, E/A, and RV dilatation were similar among survivors and non-survivors.

CONCLUSION

Echocardiographic evaluation in COVID-19 patients showed severe LV systolic dysfunction was associated with ICU mortality. E/e' was not found to be significant but lower e' was associated with higher mortality. Trial registration IEC 131/2020, CTRI/2020/06/025858 date 13th June 2020.

Indications, Clinical Impact, and Complications of Critical Care Transesophageal Echocardiography: A Scoping Review

BACKGROUND

Critical care transesophageal echocardiography (ccTEE) is an increasingly popular tool used by intensivists to characterize and manage hemodynamics at the bedside. Its usage appears to be driven by expanded diagnostic scope as well as the limitations of transthoracic echocardiography (TTE) - lack of acoustic windows, patient positioning, and competing clinical interests (eg, the need to perform chest compressions). The objectives of this scoping review were to determine the indications, clinical impact, and complications of ccTEE.

METHODS

MEDLINE, EMBASE, Cochrane, and six major conferences were searched without a time or language restriction on March 31st, 2021. Studies were included if they assessed TEE performed for adult critically ill patients by intensivists, emergency physicians, or anesthesiologists. Intraoperative or post-cardiac surgical TEE studies were excluded. Study demographics, indication for TEE, main results, and complications were extracted in duplicate.

RESULTS

Of the 4403 abstracts screened, 289 studies underwent full-text review, with 108 studies (6739 patients) included. Most studies were retrospective (66%), performed in academic centers (84%), in the intensive care unit (73%), and were observational (55%). The most common indications for ccTEE were hemodynamic instability, trauma, cardiac arrest, respiratory failure, and procedural guidance. Across multiple indications, ccTEE was reported to change the diagnosis in 52% to 78% of patients and change management in 32% to79% patients. During cardiac arrest, ccTEE identified the cause of arrest in 25% to 35% of cases. Complications of ccTEE included two cases of significant gastrointestinal bleeding requiring intervention, but no other major complications (death or esophageal perforation) reported.

CONCLUSIONS

The use of ccTEE has been described for the diagnosis and management of a broad range of clinical problems. Overall, ccTEE was commonly reported to offer additional diagnostic yield beyond TTE with a low observed complication rate. Additional high quality ccTEE studies will permit stronger conclusions and a more precise understanding of the trends observed in this scoping review.

Transesophageal Echocardiographic Assessment in Patients with Severe Respiratory Distress due to COVID-19 in the Prone Position: A Feasibility Study

Background and aim

Our aim was to assess the feasibility, safety, and utility of implementing transesophageal echocardiographic screening in patients with coronavirus disease-2019 (COVID-19)-related acute respiratory distress syndrome (ARDS), receiving mechanical ventilation (MV) and in prone position (PP).

Methods

Prospective observational study performed in an intensive care unit; patients 18 years, with ARDS, invasive MV, in PP were included. A total of 87 patients were included.

Results

There was no need to change ventilator settings, hemodynamic support, or any difficulties with the insertion of the ultrasonographic probe. Mean duration of transesophageal echocardiography (TEE) was 20 minutes. No displacement of the orotracheal tube, vomiting, or gastrointestinal bleeding was observed. Frequent complication was displacement of the nasogastric tube in 41 (47%) patients. Severe right ventricular (RV) dysfunction was detected in 21 (24%) patients and acute cor pulmonale was diagnosed in 36 (41%) patients.

Conclusion

Our results show the importance of assessing RV function during the course of severe respiratory distress and the value of TEE for hemodynamic assessment in PP.

How to cite this article

Sosa FA, Wehit J, Merlo P, Matarrese A, Tort B, Roberti JE, et al. Transesophageal Echocardiographic Assessment in Patients with Severe Respiratory Distress due to COVID-19 in the Prone Position: A Feasibility Study. Indian J Crit Care Med 2023;27(2):132-134.

[Prehospital ultrasound and cardiological emergencies]

Technological advances over the past two decades have paved the way for the prehospital use of ultrasound. This practice was first developed in traumatology and then in a multitude of other indications, including cardiology. The development of pulmonary ultrasound is certainly the most visible illustration of this. Firstly, because it is an extra-cardiac examination that provides the answer to a cardiac question. Secondly because from a theoretical point of view this ultrasound indication was a bad indication for the use of ultrasound due to the air contained in the thorax. Thirdly, because this indication has become a 'standard of care' when caring for a patient with dyspnea - a practice that has become widespread during the COVID epidemic. In patients with heart failure, ultrasound has a high diagnostic power (including for alternative diagnoses) which is all the more precise since the technique is non-invasive, the response is obtained quickly, the examination can be repeated at desire to follow the evolution of the patient. The main other indications for prehospital ultrasound are cardiac arrest to search for a curable cause, identification of residual mechanical cardiac activity, monitoring of cerebral perfusion; chest pain, for both positive and negative diagnoses; shock for the search for an etiology and therapeutic follow-up or even pulmonary embolism or ultrasound for the search for dilation of the right ventricle which is now at the forefront of the recommendation algorithm.

Hemodynamic effects and tolerance of dobutamine for myocardial dysfunction during septic shock: An observational multicenter prospective echocardiographic study

Background

The role of dobutamine during septic shock resuscitation is still controversial.

Methods

The aim of this prospective multicentre study was to comprehensively characterize the hemodynamic response of septic shock patients with systolic myocardial dysfunction to incremental doses of dobutamine (0, 5, 10, and 15 μg/kg/min).

Results

Thirty two patients were included in three centers. Dobutamine significantly increased contractility indices of both ventricles [crude and afterload-adjusted left ventricular (LV) ejection fraction, global LV longitudinal peak systolic strain, tissue Doppler peak systolic wave at mitral and tricuspid lateral annulus, and tricuspid annular plane excursion) as well as global function indices (stroke volume and cardiac index) and diastolic function (increased e' and decreased E/e' ratio at lateral mitral annulus). Dobutamine also induced a significant decrease in arterial pressure and cardiac afterload indices (effective arterial elastance, systemic vascular resistance and diastolic shock index). Oxygen transport, oxygen consumption and carbon dioxide production all increased with dobutamine, without change in the respiratory quotient or lactate. Dobutamine was discontinued for poor tolerance in a majority of patients (n = 21, 66%) at any dose and half of patients (n = 15, 47%) at low-dose (5 μg/kg/min). Poor tolerance to low-dose dobutamine was more frequent in case of acidosis, was associated with lower vasopressor-free days and survival at day-14.

Conclusion

In patients with septic myocardial dysfunction, dobutamine induced an overall improvement of echocardiographic parameters of diastolic and systolic function, but was poorly tolerated in nearly two thirds of patients, with worsening vasoplegia. Patients with severe acidosis seemed to have a worse response to dobutamine.

Septic cardiomyopathy: Diagnosis and management

There is an extensive body of literature focused on sepsis-induced myocardial dysfunction, but results are conflicting and no objective definition of septic cardiomyopathy (SCM) has been established. SCM may be defined as a sepsis-associated acute syndrome of non-ischemic cardiac dysfunction with systolic and/or diastolic left ventricular (LV) dysfunction and/or right ventricular dysfunction. Physicians should consider this diagnosis in patients with sepsis-associated organ dysfunction, and particularly in cases of septic shock that require vasopressors. Echocardiography is currently the gold standard for diagnosis of SCM. Left ventricular ejection fraction is the most common parameter used to describe LV function in the literature, but its dependence on loading conditions, particularly afterload, limits its use as a measure of intrinsic myocardial contractility. Therefore, repeated echocardiography evaluation is mandatory. Evaluation of global longitudinal strain (GLS) may be more sensitive and specific for SCM than LV ejection fraction (LVEF). Standard management includes etiological treatment, adapted fluid resuscitation, use of vasopressors, and monitoring. Use of inotropes remains uncertain, and heart rate control could be an option in some patients.

Diaphragm Thickening During Venoarterial Extracorporeal Membrane Oxygenation Weaning: An Observational Prospective Study

OBJECTIVES

The respiratory workload, according to the diaphragm thickening fraction (TF) during sweep gas flow (SGF), decrease during weaning from venoarterial extracorporeal membrane oxygenation (VA ECMO) was evaluated for the present study.

DESIGN

Prospective observational study.

SETTING

Monocentric.

PARTICIPANTS

Patients were included if they were suitable for a first VA ECMO weaning trial and were breathing spontaneously.

INTERVENTIONS

SGF was set for 15 minutes when the TF was measured at 4 L/min, 2 L/min, and 1 L/min, with a 10-minute return to baseline between each step. Mechanical ventilation, when required, was set to pressure-support ventilation mode with 7 cmH₂O (pressure support) and a positive end-expiratory pressure of 0 cmH₂O. Diaphragm ultrasound was used to assess the TF at the end of each step. Demographics, left ventricular ejection fraction (LVEF), and outcome were collected.

MEASUREMENTS AND MAIN RESULTS

Fifteen patients were included. Ten patients were extubated, and five were ventilated. TF values were 6.3% [0-10] at 4 L/min, 13.3% [10-26] at 2 L/min, and 26.7% [22-44] at 1 L/min (analysis of variance: p < 0.001 between 4 L/min and 2 L/min and p = 0.03 between 2 L/min and 1 L/min). TF did not differ whether patients were or were not ventilated or whether they were or were not weaned successfully from ECMO. TF was correlated with LVEF at 1 L/min SGF (Pearson R 0.67 [0.21-0.88]; p = 0.009) and at 2 L/min (R 0.7 [0.27-0.89]; p = 0.005) but not at 4 L/min. SGF mitigated the relationship between LVEF and TF (analysis of covariance: p < 0.005).

CONCLUSIONS

Diaphragm TF was related to the SGF of the venoarterial ECMO settings and LVEF at the time of weaning.

Hemodynamic monitoring using trans esophageal echocardiography in patients with shock

Circulatory shock is a life-threatening condition responsible for inadequate tissue perfusion. The objectives of hemodynamic monitoring in this setting are multiple: identifying the mechanisms of shock (hypovolemic, distributive, cardiogenic, obstructive); choosing the adequate therapeutic intervention, and evaluating the patient's response. Echocardiography is proposed as a first line tool for this assessment in the intensive care unit. As compared to trans-thoracic echocardiography (TTE), trans-esophageal echocardiography (TEE) offers a better echogenicity and is the best way to evaluate deep anatomic structures. The therapeutic implication of TEE leads to frequent changes in clinical management. It also allows depicting sources of inaccuracy of thermodilution-based hemodynamic monitoring. It is a semi invasive tool with a low rate of complications. The first step in the hemodynamic evaluation of shock is to characterize the mechanisms of circulatory failure among hypovolemia, vasoplegia, cardiac dysfunction, and obstruction. Echocardiographic evaluation includes evaluation of LV systolic and diastolic function, as well as RV function, pericardium, measure of stroke volume and cardiac output, and evaluation of hypovolemia and fluid responsiveness. TEE can be used as a semi-continuous monitoring tool and can be repeated before and after therapeutic interventions (vasopressors, inotropes, fluid therapy, specific treatment such as pericardial effusion evacuation) to evaluate efficacy and tolerance of therapeutic interventions. In conclusion, TEE plays an important role in the management of circulatory failure when TTE is not enough to answer to the questions, although it is not a continuous tool of monitoring. TEE results must be integrated in a global evaluation, the first step being clinical examination. Whether TEE-directed therapy and close hemodynamic monitoring of shock has an impact on outcome remains debated.

Impact of Critical Care Transesophageal Echocardiography in Medical-Surgical ICU Patients: Characteristics and Results From 274 Consecutive Examinations

OBJECTIVE

Critical care echocardiography has become an integral tool in the assessment and management of critically ill patients. Critical care transesophageal echocardiography (TEE) offers diagnostic reliability, superior image quality, and an expanded diagnostic scope to transthoracic echocardiography. Despite its favorable attributes, TEE use in North American intensive care units (ICUs) remains relatively undescribed. In this article, we seek to characterize the feasibility, indications, and clinical impact of a critical care TEE program.

DESIGN

Retrospective, observational study.

SETTING

Tertiary care, academic critical care program consisting of 2 hospitals in Ontario, Canada.

PARTICIPANTS

Consecutive critical care TEE examinations on ICU patients performed between December 2012 and December 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Consecutive critical care TEE studies on ICU patients from December 1, 2012, to December 31, 2016, were reviewed. The TEEs performed on cardiac surgery patients and those without reports were excluded. Examination details, including indications, complications, examination complexity (number of views, Doppler techniques), and clinical recommendations were aggregated and analyzed. Two hundred seventy-four TEE studies were performed by 38 operators. Common indications for TEE studies were hemodynamic instability (45.2%), assessment for infective endocarditis (22.2%), and cardiac arrest (20.1%). A change in patient management was proposed following 79.5% of TEE studies. Thirty-eight percent of TEE studies were performed during evening hours or on weekends. There were no mechanical complications.

CONCLUSIONS

Our observational data support intensivist-performed TEE as being safe and therapeutically influential across a broad range of indications. Our program's demonstrated feasibility and impact may act as a model for TEE adoption in other North American ICUs.

Pulmonary Vascular Dysfunction and Cor Pulmonale During Acute Respiratory Distress Syndrome in Sicklers

BACKGROUND

Acute chest syndrome (ACS) is the most common cause of death among sickle cell disease (SCD) adult patients. Pulmonary vascular dysfunction (PVD) and acute cor pulmonale (ACP) are common during acute respiratory distress syndrome (ARDS) and their prevalence may be even more important during ARDS related to ACS (ACS-ARDS). The objective of this study was to evaluate the prevalence and prognosis of PVD and ACP during ACS-ARDS.

PATIENTS AND METHODS

This was a retrospective analysis over a 10-year period of patients with moderate-to-severe ARDS. PVD and ACP were assessed by echocardiography. ARDS episodes were assigned to ACS-ARDS or nonACS-ARDS group according to whether the clinical insult was ACS or not, respectively. To evaluate independent factors associated with ACP, significant univariable risk factors were examined using logistic regression and propensity score analyses.

RESULTS

A total of 362 patients were analyzed, including 24 ACS-ARDS. PVD and ACP were identified, respectively, in 24 (100%) and 20 (83%) ACS-ARDS patients, as compared with 204 (60%) and 68 (20%) nonACS-ARDS patients (P < 0.0001). The mortality did not differ between ACS-ARDS and nonACS-ARDS patients. Both the crude (odds ratio [OR], 19.9; 95% confidence interval [CI], 6.6-60; P < 0.0001), multivariable adjustment (OR, 27.4; 95% CI, 8.2-91.5; P < 0.001), and propensity-matched (OR, 11.7; 95% CI, 1.2-110.8; P = 0.03) analyses found a significant association between ACS-ARDS and ACP.

CONCLUSIONS

All SCD patients presenting with moderate-to-severe ARDS as a consequence of ACS experienced PVD and more than 80% of them exhibited ACP. These results suggest a predominant role for PVD in the pathogenesis of severe forms of ACS.

Lung and cardiac ultrasound for hemodynamic monitoring of patients with severe pre-eclampsia

OBJECTIVE

To evaluate lung and cardiac ultrasound for the assessment of fluid tolerance and fluid responsiveness before and after delivery in pregnant women with severe pre-eclampsia (PE).

METHODS

This was a prospective observational study of singleton pregnant women with severe PE and healthy term controls. Lung ultrasound echo comet score (ECS), which denotes the amount of extravascular lung water, was obtained using the 28-rib interspaces technique. The echocardiographic E/e' ratio, measured by pulsed-wave and tissue Doppler, was used as a marker of diastolic left ventricular function. Fluid responsiveness was assessed by measuring changes in stroke volume (SV) with passive leg raising (PLR). SV was calculated from the left ventricular flow velocity-time integral measured by pulsed-wave Doppler at baseline and after PLR. Change in SV ≥ 12% was considered to indicate fluid responsiveness. Measurements obtained 1 day before delivery and 1 and 4 days after delivery were compared in the two groups (PE vs controls).

RESULTS

We included 21 women with severe PE and 12 healthy controls. ECS and E/e' ratio were higher in women with PE than in controls, both before delivery (P = 0.002 and P = 0.02) and 1 day postdelivery (P = 0.02 and P = 0.03); however there was no difference at 4 days postdelivery (P = 0.63 and P = 0.90). The change in SV with PLR before (P = 0.26) and after (P = 0.71) delivery did not differ between groups. An increase in SV ≥ 12% was observed in three (14%) women with PE and four (33%) controls before delivery and in four (19%) women with PE and two (17%) controls 1 day after delivery.

CONCLUSIONS

Severe PE is associated with an increase in extravascular lung water, which could in part be caused by disturbed diastolic left ventricular function. Excess lung water can be identified by lung ultrasound assessment in women with severe PE before the appearance of clinical signs. Only a small proportion of these women are fluid responsive. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Three-dimensional transoesophageal echocardiography for cardiac output in critically ill patients: A pilot study of ultrasound versus the thermodilution method

BACKGROUND

Three-dimensional transoesophageal echocardiography (3D-TOE) is a new noninvasive tool for quantitative assessment of left ventricular (LV) volumes and ejection fraction.

AIM

The objective of this pilot study was to evaluate the feasibility and accuracy of 3D-TOE for the estimation of cardiac output (CO), using transpulmonary thermodilution with the Pulse index Contour Continuous Cardiac Output (PiCCO) system as the reference method, in intensive care unit (ICU) patients.

METHODS

Fifteen ICU patients on mechanical ventilation prospectively underwent PiCCO catheter implantation and 3D-TOE. 3D-TOE LV end-diastolic and end-systolic volumes were determined using semi-automated software. CO was calculated as the product of LV stroke volume (end-diastolic volume-end-systolic volume) multiplied by heart rate. CO was also determined invasively by transpulmonary thermodilution as the reference method.

RESULTS

Among 30 haemodynamic evaluations, 29 (97%) LV 3D-TOE datasets were suitable for CO calculation. The mean 3D-TOE image acquisition and post-processing times were 46 and 155seconds, respectively. There was a correlation (r=0.78; P<0.0001) between PiCCO and 3D-TOE CO. Compared with PiCCO, the 3D-TOE CO mean bias was 0.38L/min, with limits of agreement of -1.97 to 2.74L/min.

CONCLUSIONS

Noninvasive estimation of CO by 3D-TOE is feasible in ICU patients. This new semi-automated modality is an additional promising tool for noninvasive haemodynamic assessment of ICU patients. However, the wide limits of agreement with thermodilution observed in this pilot study require further investigation in larger cohorts of patients.

Post-cardiac arrest shock treated with veno-arterial extracorporeal membrane oxygenation: An observational study and propensity-score analysis

PURPOSE

Cardiogenic shock due to post-resuscitation myocardial dysfunction is a major cause of mortality among patients hospitalized after cardiac arrest (CA). Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been proposed in the most severe cases but the level of evidence is very low. We assessed characteristics, outcome and prognostic factors of patients treated with VA-ECMO for post-CA shock.

METHODS

Using a large regional registry, we focused on all CA admitted in ICU. Among those who developed a post-CA shock, prognostic was compared according to VA-ECMO use, using logistic regression and propensity score. Specific prognostic factors were identified among VA-ECMO patients.

RESULTS

Among 2988 patients admitted after CA, 1489 developed a post-CA shock, and were included. They were mostly male (68%), with mean age 63 years (SD=15). Fiflty-two patients (3.5%) were treated with VA-ECMO, mostly patients with ischemic cause of CA (67%). Among patients with post-CA shock, 312 (21%) were discharged alive (25% in VA-ECMO group, 21% in control group, P=0.45). After adjustment for pre-hospital and in-hospital factors, survival did not differ among patients treated with VA-ECMO (OR for survival=0.9, 95%CI 0.4-2.3, P=0.84). After propensity-score matching, results were consistent. Among patients treated with VA-ECMO, initial arterial pH (OR=1.7 per 0.1 increase, 95%CI 1.0-2.8, P=0.04) and implantation of VA-ECMO over 24h after ROSC (OR=20.0, 95%CI 1.4-277.3, P=0.03) were associated with survival.

CONCLUSIONS

Post-CA shock is frequent and is associated with a high mortality rate. When used in selected patients, we observed that VA-ECMO could be an appropriate treatment.

Two-dimensional-strain echocardiography in intensive care unit patients: A prospective, observational study

PURPOSE

Two-dimensional-strain echocardiography (2D-strain) is a promising technique for the early detection of myocardial dysfunction. Our study was aimed to assess its feasibility in the intensive care unit (ICU). Our secondary goal was to determine if 2D-strain could predict the patient's outcome.

METHODS

Conventional echocardiography and 2D-strain were performed on 64 consecutive patients admitted to our ICU. Using 2D-strain, the longitudinal deformation of the left ventricle was assessed. Feasibility of 2D-strain, diagnosis performance, and 28-day mortality prediction were determined.

RESULTS

2D-strain measurements could be performed in 77% of our patients. All 2D-strain variables related to ventricular performance were significantly impaired in the patients who died compared with those who survived. Strain global medium was the only independent echocardiographic variable predictor of 28-day mortality rate (odds ratio 0.60; 95% confidence interval 0.43-0.80, p = 0.002).

CONCLUSIONS

2D-strain measurement is feasible in ICU patients, enabling identifying early left ventricle dysfunction. Strain global medium is an independent predictor of 28-day mortality. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:368-374, 2016.

The Use of Ultrasound in Caring for Patients with Sepsis

Echocardiography is a noninvasive and accurate tool used in the intensive care unit to assess cardiac function and monitor hemodynamics in shocked patients. During severe sepsis or septic shock, several mechanisms can lead to hemodynamic failure and have to be quickly and precisely diagnosed to propose adequate, personalized, and timely hemodynamic therapy. Echocardiography truly provides intensivists with this diagnostic possibility, whether or not there is fluid responsiveness, cardiac dysfunction, or persistent vasoplegia. Acquiring skills in critical care echocardiography is mandatory in improving management and monitoring of patients with sepsis at the bedside. How critical care echocardiography in managing patients with septic shock improves prognosis remains to be elucidated.

Internal medicine point-of-care ultrasound assessment of left ventricular function correlates with formal echocardiography

PURPOSE

Although focused cardiac ultrasonographic (FoCUS) examination has been evaluated in emergency departments and intensive care units with good correlation to formal echocardiography, accuracy for the assessment of left ventricular systolic function (LVSF) when performed by internal medicine physicians still needs independent evaluation.

METHODS

This prospective observational study in a 640-bed, academic, quaternary care center, included 178 inpatients examined by 10 internal medicine physicians who had completed our internal medicine bedside ultrasound training program. The ability to estimate LVSF with FoCUS as "normal," "mild to moderately decreased," or "severely decreased" was compared with left ventricular ejection fraction (>50%, 31-49%, and <31%, respectively) from formal echocardiography interpreted by a cardiologist.

RESULTS

Sensitivity and specificity of FoCUS for any degree of LVSF impairment were 0.91 (95% confidence interval [CI] 0.80, 0.97) and 0.88 (95% CI 0.81, 0.93), respectively. The interrater agreement between internal medicine physician-performed FoCUS and formal echocardiography for any LVSF impairment was "good/substantial" with κ = 0.77 (p < 0.001), 95% CI (0.67, 0.87). Formal echocardiography was classified as "technically limited due to patient factors" in 20% of patients; however, echogenicity was sufficient in 100% of FoCUS exams to classify LVSF.

CONCLUSIONS

Internal medicine physicians using FoCUS identify normal versus decreased LVSF with high sensitivity, specificity, and "good/substantial" interrater agreement when compared with formal echocardiography. These results support the role of cardiac FoCUS by properly trained internal medicine physicians for discriminating normal from reduced LVSF.

Acute cor pulmonale during protective ventilation for acute respiratory distress syndrome: prevalence, predictors, and clinical impact

RATIONALE

Increased right ventricle (RV) afterload during acute respiratory distress syndrome (ARDS) may induce acute cor pulmonale (ACP).

OBJECTIVES

To determine the prevalence and prognosis of ACP and build a clinical risk score for the early detection of ACP.

METHODS

This was a prospective study in which 752 patients with moderate-to-severe ARDS receiving protective ventilation were assessed using transesophageal echocardiography in 11 intensive care units. The study cohort was randomly split in a derivation (n = 502) and a validation (n = 250) cohort.

MEASUREMENTS AND MAIN RESULTS

ACP was defined as septal dyskinesia with a dilated RV [end-diastolic RV/left ventricle (LV) area ratio >0.6 (≥1 for severe dilatation)]. ACP was found in 164 of the 752 patients (prevalence of 22 %; 95 % confidence interval 19-25 %). In the derivation cohort, the ACP risk score included four variables [pneumonia as a cause of ARDS, driving pressure ≥18 cm H2O, arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2) ratio <150 mmHg, and arterial carbon dioxide partial pressure ≥48 mmHg]. The ACP risk score had a reasonable discrimination and a good calibration. Hospital mortality did not differ between patients with or without ACP, but it was significantly higher in patients with severe ACP than in the other patients [31/54 (57 %) vs. 291/698 (42 %); p = 0.03]. Independent risk factors for hospital mortality included severe ACP along with male gender, age, SAPS II, shock, PaO2/FiO2 ratio, respiratory rate, and driving pressure, while prone position was protective.

CONCLUSIONS

We report a 22 % prevalence of ACP and a poor outcome of severe ACP. We propose a simple clinical risk score for early identification of ACP that could trigger specific therapeutic strategies to reduce RV afterload.

Hemodynamic assessment in the contemporary intensive care unit: a review of circulatory monitoring devices

The assessment of the circulating volume and efficiency of tissue perfusion is necessary in the management of critically ill patients. The controversy surrounding pulmonary artery catheterization has led to a new wave of minimally invasive hemodynamic monitoring technologies, including echocardiographic and Doppler imaging, pulse wave analysis, and bioimpedance. This article reviews the principles, advantages, and limitations of these technologies and the clinical contexts in which they may be clinically useful.

Hemodynamic assessment of ventilated ICU patients with cardiorespiratory failure using a miniaturized multiplane transesophageal echocardiography probe

PURPOSE

To assess the feasibility, image quality, diagnostic accuracy, therapeutic impact and tolerance of diagnostic and hemodynamic assessment using a novel miniaturized multiplane transesophageal echocardiography (TEE) probe in ventilated ICU patients with cardiopulmonary compromise.

STUDY DESIGN

Prospective, descriptive, single-center study.

METHODS

Fifty-seven ventilated patients with acute circulatory or respiratory failure were assessed, using a miniaturized multiplane TEE probe and a standard TEE probe used as reference, randomly by two independent experienced operators. Measurements of hemodynamic parameters were independently performed off-line by a third expert. Diagnostic groups of acute circulatory failure (n = 5) and of acute respiratory failure (n = 3) were distinguished. Hemodynamic monitoring was performed in 9 patients using the miniaturized TEE probe. TEE tolerance and therapeutic impact were reported.

RESULTS

The miniaturized TEE probe was easier to insert than the standard TEE probe. Despite lower imaging quality of the miniaturized TEE probe, the two probes had excellent diagnostic agreement in patients with acute circulatory failure (Kappa: 0.95; 95% CI: 0.85-1) and with acute respiratory failure (Kappa: 1; 95% CI: 1.0-1.0). Accordingly, therapeutic strategies derived from both TEE examinations were concordant (Kappa: 0.82; 95% CI: 0.66-0.97). The concordance between quantitative hemodynamic parameters obtained with both TEE probes was also excellent. No relevant complication secondary to TEE probes insertion occurred.

CONCLUSIONS

Hemodynamic assessment of ventilated ICU patients with cardiopulmonary compromise using a miniaturized multiplane TEE probe appears feasible, well-tolerated, and relevant in terms of diagnostic information and potential therapeutic impact. Further larger-scale studies are needed to confirm these preliminary results.

Echocardiographic detection of transpulmonary bubble transit during acute respiratory distress syndrome

Background

Transpulmonary bubble transit (TPBT) detected with contrast echocardiography is reported as a sign of intrapulmonary shunt during cirrhosis or exercise in healthy humans. However, its physiological meaning is not clear during acute respiratory distress syndrome (ARDS). Our aim was to determine the prevalence, significance, and prognosis of TPBT detection during ARDS.

Methods

This was a prospective observational study in an academic medical intensive care unit in France. Two hundred and sixteen consecutive patients with moderate-to-severe ARDS underwent transesophageal echocardiography with modified gelatine contrast. Moderate-to-large TPBT was defined as right-to-left passage of at least ten bubbles through a pulmonary vein more than three cardiac cycles after complete opacification of the right atrium. Patients with intra-cardiac shunt through patent foramen ovale were excluded.

Results

The prevalence of moderate-to-large TPBT was 26% (including 42 patients with moderate and 15 with large TPBT). Patients with moderate-to-large TPBT had higher values of cardiac index and heart rate as compared to those without TPBT. There was no significant difference in PaO₂/FIO₂ ratio between groups, and TPBT was not influenced by end-expiratory positive pressure level in 93% of tested patients. Prevalence of septic shock was higher in the group with moderate-to-large TPBT. Patients with moderate-to-large TPBT had fewer ventilator-free days and intensive care unit-free days within the first 28 days, and higher in-hospital mortality as compared to others.

Conclusions

Moderate-to-large TPBT was detected with contrast echocardiography in 26% of patients with ARDS. This finding was associated with a hyperdynamic and septic state, but did not influence oxygenation.

Bedside ultrasonography for the intensivist

Critical care ultrasonography is a bedside technique performed by the frontline clinician at the point of care. Point-of-care ultrasonography is conceptually related to physical examination. The intensivist uses visual assessment, auscultation, and palpation on an ongoing basis to monitor the patient. Ultrasonography adds to traditional physical examination by allowing the intensivist to visualize the anatomy and function of the body in real time. Initial, repeated, and goal-directed ultrasonography is an extension of the physical examination that allows the intensivist to establish a diagnosis and monitor the condition of the patient on a regular basis.

Predicting preload responsiveness using simultaneous recordings of inferior and superior vena cavae diameters

Introduction

Echocardiographic indices based on respiratory variations of superior and inferior vena cavae diameters (ΔSVC and ΔIVC, respectively) have been proposed as predictors of fluid responsiveness in mechanically ventilated patients, but they have never been compared simultaneously in the same patient sample. The aim of this study was to compare the predictive value of these echocardiographic indices when concomitantly recorded in mechanically ventilated septic patients.

Methods

Septic shock patients requiring hemodynamic monitoring were prospectively enrolled over a 1-year period in a mixed medical surgical ICU of a university teaching hospital (Toulouse, France). All patients were mechanically ventilated. Predictive indices were obtained by transesophageal and transthoracic echocardiography and were calculated as follows: (Dmax − Dmin)/Dmax for ΔSVC and (Dmax − Dmin)/Dmin for ΔIVC, where Dmax and Dmin are the maximal and minimal diameters of SVC and IVC. Measurements were performed at baseline and after a 7-ml/kg volume expansion using a plasma expander. Patients were separated into responders (increase in cardiac index ≥15%) and nonresponders (increase in cardiac index <15%).

Results

Among 44 included patients, 26 (59%) patients were responders (R). ΔSVC was significantly more accurate than ΔIVC in predicting fluid responsiveness. The areas under the receiver operating characteristic curves for ΔSVC and ΔIVC regarding assessment of fluid responsiveness were significantly different (0.74 (95% confidence interval (CI): 0.59 to 0.88) and 0.43 (95% CI: 0.25 to 0.61), respectively (P = 0.012)). No significant correlation between ΔSVC and ΔIVC was found (r = 0.005, P = 0.98). The best threshold values for discriminating R from NR was 29% for ΔSVC, with 54% sensitivity and 89% specificity, and 21% for ΔIVC, with 38% sensitivity and 61% specificity.

Conclusions

ΔSVC was better than ΔIVC in predicting fluid responsiveness in our cohort. It is worth noting that the sensitivity and specificity values of ΔSVC and ΔIVC for predicting fluid responsiveness were lower than those reported in the literature, highlighting the limits of using these indices in a heterogeneous sample of medical and surgical septic patients.

Ultrasound assessment of pulmonary embolism in patients receiving CT pulmonary angiography

BACKGROUND

CT pulmonary angiography (CTPA) is considered the gold standard for the diagnosis of pulmonary embolism (PE) and is frequently performed in patients with cardiopulmonary complaints. However, indiscriminate use of CTPA results in significant exposure to ionizing radiation and contrast. We studied the accuracy of a bedside ultrasound protocol to predict the need for CTPA.

METHODS

This was an observational study performed by pulmonary/critical care physicians trained in critical care ultrasonography. Screening ultrasonography was performed when a CTPA was ordered to rule out PE. The ultrasound examination consisted of a limited ECG, thoracic ultrasonography, and lower extremity deep venous compression study. We predicted that CTPA would not be needed if either DVT was found or clear evidence of an alternative diagnosis was established. CTPA parenchymal and pleural findings, and, when available, formal DVT and ECG results, were compared with our screening ultrasound findings.

RESULTS

Of 96 subjects who underwent CTPA, 12 subjects (12.5%) were positive for PE. All 96 subjects had an ultrasound study; two subjects (2.1%) were positive for lower extremity DVT, and 54 subjects (56.2%) had an alternative diagnosis suggested by ultrasonography, such as alveolar consolidation consistent with pneumonia or pulmonary edema, which correlated with CTPA findings. In no patient did the CTPA add an additional diagnosis over the screening ultrasound study.

CONCLUSIONS

We conclude that ultrasound examination indicated that CTPA was not needed in 56 of 96 patients (58.3%). A screening, point-of-care ultrasonography protocol may predict the need for CTPA. Furthermore, an alternative diagnosis can be established that correlates with CTPA. This study needs further verification, but it offers a possible approach to reduce the cost and radiation exposure that is associated with CTPA.

Lung Ultrasound Predicts Interstitial Syndrome and Hemodynamic Profile in Parturients with Severe Preeclampsia

Background:

The role of lung ultrasound has never been evaluated in parturients with severe preeclampsia. The authors’ first aim was to assess the ability of lung ultrasound to detect pulmonary edema in severe preeclampsia. The second aim was to highlight the relation between B-lines and increased left ventricular end-diastolic pressures.

Methods:

This prospective cohort study was conducted in a level-3 maternity during a 12-month period. Twenty parturients with severe preeclampsia were consecutively enrolled. Both lung and cardiac ultrasound examinations were performed before (n = 20) and after delivery (n = 20). Each parturient with severe preeclampsia was compared with a control healthy parturient. Pulmonary edema was determined using two scores: the B-pattern and the Echo Comet Score. Left ventricular end-diastolic pressures were assessed by transthoracic echocardiography.

Results:

Lung ultrasound detected interstitial edema in five parturients (25%) with severe preeclampsia. A B-pattern was associated to increased mitral valve early diastolic peak E (116 vs. 90 cm/s; P = 0.05) and to increased E/E’ ratio (9.9 vs. 6.6; P &lt; 0.001). An Echo Comet Score of greater than 25 predicted an increase in filling pressures (E/E’ ratio &gt;9.5) with a sensitivity and specificity of 1.00 (95% CI, 0.69 to 1.00) and 0.82 (95% CI, 0.66 to 0.92), respectively.

Conclusions:

In parturients with severe preeclampsia, lung ultrasound detects both pulmonary edema and increased left ventricular end-diastolic pressures. The finding of a B-pattern should restrict the use of fluid. However, these preliminary results are associations from a single sample. They need to be replicated in a larger, definitive study.

Feasibility of diagnosis of postcardiotomy tamponade by miniaturized transesophageal echocardiography

BACKGROUND

Pericardial tamponade after cardiac surgery is a critical diagnosis that can be difficult to diagnose using conventional cardiac monitoring. Transesophageal echocardiography can provide comprehensive information to make the diagnosis but is not always available, whereas transthoracic echocardiography has its utility limited because of the body habitus or other surgical effects. New monitoring devices, miniaturized hemodynamic transesophageal echocardiography (hTEE), which allows point of care assessment of cardiac filling and functions, may aid in diagnosis of postcardiotomy tamponade.

METHODS

From May 2011 to July 2013, 21 patients underwent hTEE to rule out pericardial tamponade for clinical suspicion of tamponade after open heart surgery. The hTEE images were reviewed, and the patient outcomes were analyzed.

RESULTS

Nine patients showed no evidence of pericardial collection and did not require reexploration. Two patients showed a presence of small hematoma without ventricular compression and also did not undergo exploration. Ten patients were positive for pericardial tamponade (effusion or hematoma with ventricular compression); eight of these cases underwent emergent surgical exploration. Of the two patients who did not undergo immediate reoperation, one was managed by chest tube manipulation and the other patient underwent subsequent surgical exploration after his extensive coagulopathy was corrected by medical treatment.

CONCLUSIONS

The diagnosis of pericardial tamponade postcardiotomy is feasible using a disposable hTEE based on our limited experience. We avoided unnecessary explorations while concomitantly made prompt diagnosis in emergent situations. The hTEE device was a valuable tool in hemodynamic management in the intensive care unit, allowing rapid evaluations.

The gray zone of the qualitative assessment of respiratory changes in inferior vena cava diameter in ICU patients

Introduction

Transthoracic echocardiography (TTE) is a useful tool for minimally invasive hemodynamic monitoring in the ICU. Dynamic indices (such as the inferior vena cava distensibility index (dIVC)) can be used to predict fluid responsiveness in mechanically ventilated patients. Although quantitative use of the dIVC has been validated, the routinely used qualitative (visual) approach had not been assessed before the present study.

Methods

Qualitative and quantitative assessments of the dIVC were compared in a prospective, observational study. After operators with differing levels in critical care echocardiography had derived a qualitative dIVC, the last (expert) operator performed a standard, numeric measurement of the dIVC (referred to as the quantitative dIVC). Two groups of patients were separated into two groups: group (dIVC < 18%) and group (dIVC ≥ 18%).

Results

In total, 114 patients were assessed for inclusion, and 97 (63 men and 34 women) were included. The mean sensitivity and specificity values for qualitative assessment of the dIVC by an intensivist were 80.7% and 93.7%, respectively. A qualitative evaluation detected all quantitative dIVCs >40%. Most of the errors concerned quantitative dIVCs of between 15% and 30%. In the dIVC <18% group, two qualitative evaluation errors were noted for quantitative dIVCs of between 0 and 10%. The average of positive predictive values and negative predictive values for qualitative assessment of the dIVC by residents, intensivists and cardiologists were 83%, 83%, and 90%; and 92%, 94%, and 90%, respectively. The Fleiss kappa for all operators was estimated to be 0.68, corresponding to substantial agreement.

Conclusion

The qualitative dIVC is a rather easy and reliable assessment for extreme numeric values. It has a gray zone between 15% and 30%. The highest and lowest limitations of the gray area are rather tedious to define.

Despite reliability of the qualitative assessment when it comes to extreme to numerical values, the quantitative dIVC measurement must always be done within a hemodynamic assessment for intensive care patients. The qualitative approach can be easily integrated into a fast hemodynamic evaluation by using portable ultrasound scanner for out-of-hospital patients.

Pulmonary Arterial Hypertension in Intensive Care Unit

For the intensive care unit (ICU) physician, the diagnosis of pulmonary arterial hypertension (PAH) is difficult as it can easily be confounded with other forms of pulmonary hypertension (PH). The key issue is that PAH is a form of PH. On the opposite, PH does not automatically imply PAH. Pulmonary arterial hypertension must be differentiated from other causes of PH that are frequently seen in ICU. It was recently emphasized that pulmonary veno-occlusive disease (PVOD) must be differentiated from PH and PAH. The prognosis of PAH was consistently improved in the ten past years by introduction of selective pulmonary vasodilators and management by highly specialized medical teams. In ICU patients, PAH remains a severe disease with a high mortality rate. When PAH is suspected, a systematic diagnosis approach is of particular importance in order to rapidly eliminate left cardiac, thromboembolic and pulmonary causes of PH. Left cardiac disease is the most common cause of PH. Early recognition of PAH allows a rapid introduction of selective pulmonary vasodilators that can improve outcome. Idiopathic PAH is the most frequent cause but it can also be associated with scleroderma, HIV infection, anorexigen toxicity, thyroid disease, cirrhosis. Pulmonary vasodilators should be only a part of a general management including treatment of triggering factors, optimization of fluid balance, decrease of RV afterload by using pulmonary vasodilators while maintaining cardiac output and mean arterial pressure. The early contact of PH referral center or specialized physician is of particular importance.

Prevalence and prognosis of cor pulmonale during protective ventilation for acute respiratory distress syndrome

PURPOSE

Pulmonary vascular dysfunction is common during acute respiratory distress syndrome (ARDS), but there is controversy concerning prevalence and prognosis of cor pulmonale during protective ventilation for ARDS.

METHODS

This was a prospective observational study in an academic medical intensive care unit in France. Two hundred and twenty-six consecutive patients with moderate to severe ARDS (Berlin definition) ventilated with plateau pressure limited at 30 cmH₂O (mean PEEP of 8.8 ± 3.6 cmH₂O) underwent transesophageal echocardiography (TEE) within the first 3 days after the diagnosis of ARDS. Cor pulmonale was defined as a dilated right ventricle associated with septal dyskinesia.

RESULTS

Cor pulmonale was detected in 49 patients (prevalence of 22%; 95% confidence interval, 16-27%). Multivariate logistic regression identified infectious causes of lung injury and higher driving pressures as independent factors associated with cor pulmonale. Patients with cor pulmonale exhibited a higher incidence of shock (need for vasoactive drug) at the time of TEE and were more often managed with prone positioning and/or nitric oxide as adjunctive therapy for severe hypoxemia during ARDS course. The 28-day mortality rate was significantly higher in the group with cor pulmonale (60 vs. 36%, p < 0.01). Multivariate logistic regression identified McCabe and Jackson class, lung injury not related to pneumonia, aspiration, or sepsis, lactic acidosis, driving pressure, and cor pulmonale as independent risk factors for 28-day mortality.

CONCLUSION

Cor pulmonale occurrence is not negligible in ARDS patients ventilated with airway pressure limitation. Cor pulmonale was associated with sepsis and higher values of driving pressure and was an independent risk factor for 28-day mortality in our series.

[Fluid therapy in cardiac surgery. An update]

The anesthetist has 2 major tools for optimizing haemodynamics in cardiac surgery: Vasoactive drugs and the intravascular volume. It is necessary to identify which patients would benefit from one or the other therapies for a suitable response to treatment. Hemodynamic monitoring with the different existing parameters (pressure, volumetric static, volumetric functional and echocardiography) allows the management of these patients to be optimized. In this article a review is presented on the most recent and relevant publications, and the different tools available to control the management of the fluid therapy in this context, and to suggest a few guidelines for the haemodynamics monitoring of patients submitted to cardiac surgery. A systematic search has been made in PubMed, limiting the results to the publications over the last five years up to February 2012.

Hemodynamic assessment of critically ill patients using a miniaturized transesophageal echocardiography probe

INTRODUCTION

Hemodynamic management in intensive care patients guided by blood pressure and flow measurements often do not sufficiently reveal common hemodynamic problems. Trans-esophageal echocardiography (TEE) allows for direct measurement of cardiac volumes and function. A new miniaturized probe for TEE (mTEE) potentially provides a rapid and simplified approach to monitor cardiac function. The aim of the study was to assess the feasibility of hemodynamic monitoring using mTEE in critically ill patients after a brief operator training period.

METHODS

In the context of the introduction of mTEE in a large ICU, 14 ICU staff specialists with no previous TEE experience received six hours of training as mTEE operators. The feasibility of mTEE and the quality of the obtained hemodynamic information were assessed. Three standard views were acquired in hemodynamically unstable patients: 1) for assessment of left ventricular function (LV) fractional area change (FAC) was obtained from a trans-gastric mid-esophageal short axis view, 2) right ventricular (RV) size was obtained from mid-esophageal four chamber view, and 3) superior vena cava collapsibility for detection of hypovolemia was assessed from mid-esophageal ascending aortic short axis view. Off-line blinded assessment by an expert cardiologist was considered as a reference. Inter-rater agreement was assessed using Chi-square tests or correlation analysis as appropriate.

RESULTS

In 55 patients, 148 mTEE examinations were performed. Acquisition of loops in sufficient quality was possible in 110 examinations for trans-gastric mid-esophageal short axis, 118 examinations for mid-esophageal four chamber and 125 examinations for mid-esophageal ascending aortic short axis view. Inter-rater agreement (Kappa) between ICU mTEE operators and the reference was 0.62 for estimates of LV function, 0.65 for RV dilatation, 0.76 for hypovolemia and 0.77 for occurrence of pericardial effusion (all P<0.0001). There was a significant correlation between the FAC measured by ICU operators and the reference (r=0.794, P (one-tailed)<0.0001).

CONCLUSIONS

Echocardiographic examinations using mTEE after brief bed-side training were feasible and of sufficient quality in a majority of examined ICU patients with good inter-rater reliability between mTEE operators and an expert cardiologist. Further studies are required to assess the impact of hemodynamic monitoring by mTEE on relevant patient outcomes.

A pilot study on safety and clinical utility of a single-use 72-hour indwelling transesophageal echocardiography probe

PURPOSE

To evaluate the hemodynamic monitoring capability and safety of a single-use miniaturized transesophageal echocardiography (TEE) probe left in place in ventilated critically ill patients.

METHODS

The probe was inserted in 94 patients and designed to be left in place for up to 72 h. Three views were obtained: the superior vena caval transverse, the mid-esophageal four-chamber, and the transgastric mid-papillary short-axis views. Observational data on the feasibility of insertion, complications, image quality, and influence on management were recorded and analyzed.

RESULTS

No failure of probe insertion was observed. The nasogastric tube had to be removed in 17 % of cases. Image quality was judged as adequate or optimal in 91/94 (97 %) of cases in the superior vena caval view, 89/94 (95 %) of cases in the four-chamber view, and 86/94 (91 %) of cases in the short-axis view. The duration of monitoring was 32 ± 23 h, allowing 2.8 ± 1.6 hemodynamic evaluations per patient that led to a mean of 1.4 ± 1.5 therapeutic changes per patient. Among the 263 hemodynamic assessments, 132 (50 %) had a direct therapeutic impact in 62 patients (66 %). Two patients developed lip ulceration from the probe, and two patients had self-limited gastric bleeding.

CONCLUSION

The single-use miniaturized probe could be inserted in all patients. Image quality was acceptable in the majority of cases, and the information derived from the device was useful in making management decisions in patients with hemodynamic failure on ventilatory support. Further studies are needed to confirm the good tolerance and to compare the new device with other hemodynamic monitoring techniques.

Respiratory variations of inferior vena cava diameter to predict fluid responsiveness in spontaneously breathing patients with acute circulatory failure: need for a cautious use

INTRODUCTION

To investigate whether respiratory variation of inferior vena cava diameter (cIVC) predict fluid responsiveness in spontaneously breathing patients with acute circulatory failure (ACF).

METHODS

Forty patients with ACF and spontaneous breathing were included. Response to fluid challenge was defined as a 15% increase of subaortic velocity time index (VTI) measured by transthoracic echocardiography. Inferior vena cava diameters were recorded by a subcostal view using M Mode. The cIVC was calculated as follows: (Dmax - Dmin/Dmax) × 100 and then receiver operating characteristic (ROC) curves were generated for cIVC, baseline VTI, E wave velocity, E/A and E/Ea ratios.

RESULTS

Among 40 included patients, 20 (50%) were responders (R). The causes of ACF were sepsis (n = 24), haemorrhage (n = 11), and dehydration (n = 5). The area under the ROC curve for cIVC was 0.77 (95% CI: 0.60-0.88). The best cutoff value was 40% (Se = 70%, Sp = 80%). The AUC of the ROC curves for baseline E wave velocity, VTI, E/A ratio, E/Ea ratio were 0.83 (95% CI: 0.68-0.93), 0.78 (95% CI: 0.61-0.88), 0.76 (95% CI: 0.59-0.89), 0.58 (95% CI: 0.41-0.75), respectively. The differences between AUC the ROC curves for cIVC and baseline E wave velocity, baseline VTI, baseline E/A ratio, and baseline E/Ea ratio were not statistically different (p = 0.46, p = 0.99, p = 1.00, p = 0.26, respectively).

CONCLUSION

In spontaneously breathing patients with ACF, high cIVC values (>40%) are usually associated with fluid responsiveness while low values (< 40%) do not exclude fluid responsiveness.

Influence of acute preload changes on mitral annulus velocity measured by tissue Doppler echocardiography in critically ill patients

AIM

The assessment of diastolic function remains difficult in critical care patients because of unstable preload conditions. Described as fairly insensitive to preload changes, tissue Doppler velocity measurement at the lateral mitral annulus (e' (lat) ) may help evaluate diastolic function. Our aim was to prospectively evaluate e' (lat) changes in relation to fluid expansion in critically ill patients.

METHODS

This prospective observational study was conducted in critically ill, mechanically ventilated, patients in sinus rhythm without previously known cardiac disease. Echocardiography was performed before and 1 hour after a fluid challenge (infusion of Gelofusine 500 ml in 30 minutes). Conventional pulsed wave Doppler indices of left ventricular diastolic function and tissue Doppler velocity lateral (e' (lat) ) and septal (e' (sept) ) mitral annulus velocity were measured, whereas hemodynamic data were simultaneously collected.

RESULTS

Twenty patients (age, 55 ± 15 years; Simplified Acute Physiology Score II, 45 ± 10) were enrolled. Systolic function was preserved in all patients. Cardiac index increased (p < 0.05), as did early diastolic mitral velocity (E wave) (p = 0.001), and e' (lat) and e' (sept) (p = 0.02) after fluid challenge.

CONCLUSIONS

This study confirms the preload dependence and limited clinical usefulness of most Doppler variables, such as e' (lat) , to evaluate diastolic function in intensive care unit patients. Indices, such as E/e', may be of interest in these cases.

Initial Experience With ImaCor hTEE-Guided Management of Patients Following Transplant and Mechanical Circulatory Support

This study reviews an initial experience using a miniaturized transesophageal echocardiography (TEE) probe (ImaCor, Garden City, NY) with 3 patients in whom Imacor hTEE intervention was used as a point-of-care device to manage extracorporeal membrane oxygenation cannula placement, cardiac hemodynamics, and postoperative cardiac pathophysiology. The management of transplant or mechanical circulatory support (MCS) patients is especially challenging: Transplanted hearts pose unique pathophysiological challenges, and MCS significantly alters pressure–volume–flow relationships. Real-time “hemodynamic” TEE (hTEE) can help provide effective management by direct visualization of cardiac filling and function and help guide hemodynamic management. In the authors’ initial experience, hTEE can provide point-of-care management following transplant or MCS.