Pandompatam, Govind

Emerging evidence links veno-venous extracorporeal membrane oxygenation (VV-ECMO) to right ventricular (RV) dysfunction, but the relative contribution of ECMO versus underlying disease progression remains unclear. We conducted a multicenter, retrospective, propensity-matched study including 408 intubated acute respiratory distress syndrome (ARDS) patients who were admitted between January 2020 and October 2024 in a quaternary referral hospital network within the United States and underwent at least two transthoracic echocardiograms (TTEs) after intubation. Using 1:2 propensity score matching, we adjusted for baseline comorbidities, baseline hemoglobin, lactate, and worst PaO 2 /FiO 2 ratio (P/F). Longitudinal echocardiographic changes were analyzed with a cumulative link mixed model (CLMM), evaluating RV size and function as ordinal outcomes. Within 408 patients (112 received ECMO support), propensity matching identified 55 ECMO and 110 non-ECMO patients with balanced baseline characteristics. Among 469 serial echocardiograms, RV size and function worsened more frequently in ECMO patients. In longitudinal modeling, ECMO use alone was not associated with RV dilation ( p = 0.23) or dysfunction ( p = 0.43). However, longer ECMO duration was associated with RV dilation (OR: 1.04 per day, p = 0.004) and dysfunction (odds ratio [OR]: 1.04 per day, p < 0.001). Higher ECMO circuit flow had a trend toward progressive RV dilation and dysfunction but did not reach statistical significance. These findings highlight the need for vigilant RV monitoring during ECMO support.

Background: The role of venous Doppler ultrasound in assessing venous congestion in the setting of post-lung transplantation surgery is unknown. We performed a feasibility study on the use of venous Doppler ultrasound in the immediate post-operative period after lung transplantation in a retrospective, single-center observational evaluation. Patients had at least two venous congestion Doppler ultrasound exams involving interrogation of IVC diameter, hepatic vein, portal vein and renal vein Doppler assessments. Results: A total of 9 patients were included in our study with a median age of 60 years, 66.7% being male, and a median BMI of 20.9. All patients had VExUS grade ≥1 on their first venous Doppler exam. All nine patients had a decrease in portal vein pulsatility from initial to final exams. Correlation between portal venous pulsatility and net fluid balance was not statistically significant R= 0.33 (P= 0.39). Other parameters, including VExUS grade, IVC diameter, HV and RV Doppler changes from initial to final ultrasound exams showed variable changes in the post-operative period. Conclusion: Venous congestion Doppler ultrasound assessments appear feasible in immediate postoperative lung transplant patients. A multitude of factors beyond fluid status likely affect waveforms.

Basic concepts of point of care ultrasound (POCUS) include ultrasound physics, imaging modes, and knobology. Ultrasound physics describes the nature of sound waves and their interaction with media. Key physics concepts include imaging resolution, transducer components, and artifacts. Having a base understanding of ultrasound physics is important to obtaining quality imaging and helps to avoid errors in acquiring and interpreting POCUS. Ultrasound modes, including two-dimensional (2D), M-mode and Doppler ultrasound allow the practitioner to evaluate many structural and hemodynamic variables in the critically ill patient. Ultrasound knobology describes the use of the ultrasound machine controls to optimize image quality. With a sound knowledge of the basics of ultrasound, practitioners can competently perform POCUS in the critical care setting.

The aortic pulsatility index (API) (systolic blood pressure-diastolic blood pressure/pulmonary capillary wedge pressure [PCWP]) integrates ventricular output with left ventricular (LV) filling pressures. It offers a surrogate for ventricular-arterial coupling and is associated with the need for advanced therapies and outcomes in decompensated heart failure. However, its use in patients in cardiogenic shock requiring temporary mechanical circulatory support (tMCS) is limited and requires invasive measurement of PCWP. This case series evaluates the concept of echo-API as a noninvasive tool to estimate API using Doppler echocardiography, and its feasibility in patients with cardiogenic shock on tMCS.

Extracorporeal membrane oxygenation (ECMO) is often used in acute respiratory distress syndrome (ARDS) with refractory hypoxemia. There is limited literature highlighting the development of right ventricular (RV) failure while on ECMO. We conducted a retrospective multicenter observational study including 70 patients who were placed on veno-venous (VV)-ECMO for respiratory failure at Mayo Clinic, Jacksonville, and Mayo Clinic, Rochester, between January 2018 and June 2022 and had at least two post-ECMO transthoracic echoes. The primary outcomes were the incidence and progression of RV dysfunction and dilatation. The secondary outcome was in-patient mortality. Among 70 patients in our cohort, 60.6% had a normal RV function at the time of ECMO placement, whereas only 42% had a normal RV function at the second post-ECMO echo. On multinomial regression, a moderate decrease in RV function was associated with ECMO flow (odds ratio [OR] = 2.32, p = 0.001) and ECMO duration (OR = 1.01, p = 0.01). A moderately dilated RV size was also associated with ECMO flow (OR = 2.62, p < 0.001) and ECMO duration (OR = 1.02, p = 0.02). An increasing degree of RV dysfunction was associated with worse outcomes. Our study showed that the increasing duration and flow of VV-ECMO correlated with progressive RV dilatation and dysfunction, which were associated with poor survival.

Lung ultrasound (LUS) detects the presence of extravascular lung water (EVLW) through the visualization of B-Line artifacts. However, the qualitative nature of LUS limits its effectiveness in serial or longitudinal studies such as evaluating changes in EVLW at different time points in patients undergoing diuretic therapy for congestive heart failure. Lung ultrasound surface wave elastography (LUSWE) is a novel technique using a small handheld device that can measure superficial lung tissue elastic properties. We aimed to evaluate the use of LUSWE to measure quantitative changes in lung elasticity caused by acute changes in EVLW. We performed LUSWE on consecutive days in 14 patients hospitalized for acute congestive heart failure with evidence of pulmonary edema (clinical EVLW). From day#1 to day#2, the patients had an average diuresis of net negative 2.1 l associated with an average decrease in 13 B-Lines by lung ultrasound, signifying a reduction in EVLW. LUSWE analysis demonstrated a significant reduction (p &lt; 0.05) in surface wave velocity in all interrogated intercostal spaces from day#1 to day#2. In summary, LUSWE performed at the bedside was able to demonstrate improvement in lung compliance (decreased elasticity) correlating with a reduction in EVLW in hospitalized patients being treated for congestive heart failure.