Diagnostic and Therapeutic Impact of Critical Care Echocardiography in Patients Admitted in the Intensive Care Unit for Circulatory Or Respiratory Failure Report from an Expert Center

Abstract

Purpose

Critical Care Echocardiography (CCE) is now a major tool in assessments of ICU patients. We aimed to evaluate its clinical impact in patients admitted to the intensive care unit for acute respiratory failure (ARF) or shock.

Methods

We conducted a single-center retrospective observational study of all patients admitted between January 1th and December 31st 2019 for ARF or shock, who received CCE in the first 12 h of admission. The primary outcome was the therapeutic impact associated with CCE. Secondary outcomes included differences in therapeutic impact between ARF and shock patients, and between trans-thoracic (TTE) and trans-esophageal (TEE) CCE.

Results

486 patients were potentially eligible, 109 were excluded because CCE was performed after 12 h or because of missing CCE report. 329 patients were analyzed, 31% with shock, 44% with ARF, 25% with both. TTE was performed in 71%, TEE in 29%. All TEE patients were invasively mechanically ventilated and 65% of invasively ventilated patients underwent TEE. No TEE-related complications were observed. CCE was followed with 363 therapeutic interventions in 231 (70%) patients within 2 h. The most common involved hemodynamic optimization in 193 patients (59%), including fluid expansion (129 patients, 39%), vasopressor initiation (39 patients, 12%), vasopressor dose adjustment (79 patients, 24%), inotrope initiation (15 patients, 4.5%), inotrope dose adjustment (5 patients), and others like cardioversion (4 patients) and veno-arterial ECMO implantation (3 patients). TEE patients were more likely to receive therapeutic changes, notably significantly more fluids (53% vs 34% p = 0.0014) and had more frequent vasopressor dose adjustments (64% vs 24% p < 0.001).

Conclusions

CCE was followed with therapeutic interventions in nearly 70% of patients admitted for ARF or shock, emphasizing its diagnostic value. Hemodynamic optimization was the primary intervention. We have not found any complications or adverse events of TEE in our cohort.

Critical care echocardiography (CCE) is one of the main tools in understanding acute respiratory failure (ARF) or shock. Our ICU has a long-standing practice of performing both trans-esophageal (TEE) notably in mechanically ventilated patients, or trans-thoracic (TTE) echocardiography. The aim of this study was to assess the impact of CCE performed at admission during the year 2019 for patients admitted for either ARF or shock patients in our ICU, in terms of CCE diagnostic and therapeutic impact. Inclusion criteria were: admission of adult patients for shock/ARF based on standard definitions and having received CCE in the first 12 h following admission with a written report of the results in the patient's file. 486 patients were screened, 329 were included. 31% were admitted for shock, 45% for ARF, and 24% exhibited both at admission. Patients were under mechanical ventilation in 44% of cases, 33% received vasopressors. Shock patients were more severe than ARF patients (SAPS II 63 ± 22 vs 46 ± 15 p < 0.001). Main day 1 diagnoses were septic shock (30%), cardiogenic shock (16%) cardiac arrest (11%) and post-operative status (18%). CCE was performed in the first 1.91 ± 2.23 h and in 68% of the 486 patients screened. 71% of all included patients received TTE, 29% received TEE. 100% of TEE patients were under invasive mechanical ventilation. 65% of invasively ventilated patients received TEE. Main CCE diagnoses were left ventricle (LV) systolic dysfunction (30%), right ventricle (RV) systolic dysfunction (12%) and RV dilation (19%). Sub aortic VTI was lower in the shock group (16 ± 6 cm vs 18 ± 6 cm, p = 0.04). Main therapeutic interventions in the 2 h following CCE were fluids administration (39%), introduction of vasopressors (12%), change in vasopressor dose or therapy (24%). 15 patients received inotropes, 11 urgent coronary angiographies were performed, 3 were placed under veino-arterial ECMO (VA-ECMO), 26 received either CT or MRI, 10 thoracenteses and 1 pericardiocentesis were performed. TEE patients were significantly more exposed to fluids (53 vs 34% p = 0.0014), had more change in vasopressor therapy (64 vs 24% p < 0.001). CCE was repeated in the first 24 h in 55% of cases. ARF patients received TTE in 90% of cases, and shock patients received TEE in 68% of cases. TTE patients were significantly more admitted for RF than TEE patients (55% vs 16% p < 0.001). Therapeutic changes were more frequent in the shock group (81% vs 51% p < 0.001) compared to the ARF group. No side effect of TEE was reported. These data are in accordance with existing literature proving that TEE is a safe and efficient alternative for diagnosis of ARF or shock. This study also shows that CCE is followed by major therapeutic interventions in almost 70% of cases, thereby suggesting the interest of systematically performing one at admission, and may lead to urgent bedside diagnoses like cardiac tamponade requiring immediate intervention. Its main limitation is that we cannot ascertain causality between therapeutic interventions and CCE diagnoses, and its retrospective nature.