Introduction
Left ventricular diastolic dysfunction (LVDD) significantly impacts the outcomes of critically ill patients in the intensive care unit.
Although LVDD assessment is crucial, treatment options are limited, and there is currently no pharmacological intervention to rapidly optimize diastolic function.
The CHEOPS bundle, named after the ancient Egyptian pharaoh, serves as a potentially valuable acronym for physicians at the bedside managing critically ill patients with LVDD.
The bundle includes several elements for patient treatment. Chest Ultrasound (integrating information from echocardiography and lung ultrasound), Hemodynamics assessment (evaluating heart rate, rhythm, afterload, and vasoactive drugs), Optimization of mechanical ventilation and pulmonary circulation, and Stabilization (with cautious fluid administration and prompt removal when safe and valuable).
It is important to note that the CHEOPS bundle is based on expert opinion and is intended for the optimization and subsequent critical illness period rather than the initial resuscitation phase.
LV diastolic function: diagnosis and grading
The assessment of left ventricular diastolic dysfunction (LVDD) involves a complex interplay of variables related to the deterioration of left ventricular (LV) relaxation, compensatory rise in left atrial (LA) pressure, and reduction of LV compliance.
Unlike systolic function changes, LVDD variables follow a non-linear trajectory due to compensatory mechanisms.
Recent guidelines, such as the 2016 guidelines, have evolved to provide more precise and comprehensive classifications of LV diastolic function.
In these guidelines, LVDD is diagnosed “by definition” in patients with impaired LV systolic function, with separate assessments for patients with normal or abnormal LV systolic function.
The diagnosis is facilitated by considering four variables: LA volume, tricuspid regurgitation jet velocity (TRvel), e’ wave velocity, and E/e’ ratio.
The subsequent grading of LVDD integrates values from the trans-mitral flow.
Each variable reflects specific physiological aspects of LV diastolic function, and their assessment should consider age-specific criteria.
Guidelines and their limitations
Even if guidelines are necessary to classify LV diastolic function, the 2016 algorithm settled for the cardiology outpatients has significant drawbacks when applied in the ICU (Table 1).
LV diastolic function: impact on clinical outcome
The association between left ventricular diastolic dysfunction (LVDD) and poor patient outcomes is evident in critical illness scenarios.
Meta-analyses indicate high mortality in septic ICU patients with LVDD, with a U-shaped association noted between LV ejection fraction values and mortality in septic patients.
LVDD also plays a significant role in weaning from mechanical ventilation, where worse tissue Doppler imaging values are associated with weaning failure.
In the perioperative period, especially in cardiac and major vascular surgeries, LVDD is linked to unfavorable outcomes. However, uncertainties exist regarding the impact of LVDD on outcomes after non-cardiac non-vascular surgery due to limited preoperative assessments.
Some studies suggest associations between elevated E/e’ ratio and postoperative cardiovascular events, longer ICU, and hospital stays, while others report conflicting findings.
The complexity of LVDD assessment in perioperative settings may benefit from the implementation of artificial intelligence to enhance data quality and availability.
How to optimize lv diastolic dysfunction: the CHEOPS bundle
A parallelism was drawn between the study of left ventricular (LV) diastolic function and the “Rosetta stone,” suggesting that Doppler echocardiography serves as the clinical “Rosetta stone” for LV diastolic function analysis.
To optimize LV diastolic function in critically ill patients, a practical bundle named CHEOPS (Chest Ultrasound, Hemodynamics assessment,
Optimization of mechanical ventilation and pulmonary circulation, and Stabilization) is proposed.
The bundle, represented in a pyramidal shape reminiscent of Pharaoh Cheops’ Great Pyramid, encompasses key aspects for managing LV diastolic dysfunction (Fig 2).
Each component of the CHEOPS bundle is briefly explained, emphasizing its importance in LVDD patient care. Further details on each component can be explored elsewhere.
Items of the CHEOPS bundle
C – chest ultrasound
The integration of critical care echocardiography (CCE) and Lung Ultrasound (LUS) into routine practice is expanding, akin to the stethoscope in physical examinations.
CCE has gained prominence for hemodynamic optimization, playing a vital role in diagnosing and grading left ventricular diastolic dysfunction (LVDD). For patients with LVDD, an initial advanced CCE is deemed beneficial, facilitating follow-up assessments of changes in LV filling pressure.
Additionally, LUS serves as an invaluable tool for confirming pulmonary edema and estimating its severity across various clinical scenarios.
The combination of CCE and LUS is positioned at the apex of the proposed CHEOPS bundle, forming the “Chest US” component.
While evaluating right ventricular function during Chest US is feasible, it requires expertise, and the subjective assessment is prone to errors. Nevertheless, an initial assessment of signs of right ventricular dilatation is considered a fundamental skill in CCE, guiding the management of vasoactive drugs and mechanical ventilation settings.
HE- HEmodynamics
Optimizing hemodynamics in critically ill patients, especially those with left ventricular diastolic dysfunction (LVDD), is crucial for favorable outcomes. Tachycardia exacerbates LVDD by reducing diastolic time, making heart rate control essential.
Beta-blockers, ultrashort-acting β-blockers, and ivabradine are potential options, while dexmedetomidine may offer heart rate control and vascular responsiveness modulation. Preventing tachyarrhythmias, like atrial fibrillation (AF), is vital, and restoring sinus rhythm with amiodarone or electric cardioversion is valuable if arrhythmic events occur.
Managing afterload is key, avoiding excessive LV afterload to maintain optimal LV filling. Vasopressors should target reasonable mean arterial pressure, considering the energy-dependent nature of diastole. Inotropes, like levosimendan, may be favorable for positive inotropism in advanced LVDD.
Post-ICU recovery may involve angiotensin-converting enzyme inhibitors for LV remodeling, though long-term benefits are recognized, and acute diastolic improvement is inconclusive. Personalized approaches are essential in patient selection for tailored interventions.
OP – OPtimization of PEEP and pulmonary circulation
Elevated left ventricular (LV) filling pressures in patients with LV diastolic dysfunction (LVDD) contribute to pulmonary congestion, leading to pulmonary edema and compromised gas exchange.
Following echocardiographic assessment and hemodynamic optimization, careful management of mechanical ventilation (MV) becomes crucial. Positive end-expiratory pressure (PEEP) may benefit LV function by reducing preload and afterload, but its effects on pulmonary vascular resistances should be considered.
Optimizing MV settings, including PEEP, should focus on decreasing LV preload and afterload without causing right ventricular (RV) dilatation. During the transition from positive to negative pressure ventilation, increased venous return poses a risk of weaning failure, especially in patients with LVDD and preload unresponsiveness.
Weaning-induced pulmonary edema, associated with higher LV filling pressure, highlights the importance of fluid responsiveness assessment during the weaning process for patients with established LVDD.
S – Stabilization and fluid removal (diuresis)
The correlation between positive fluid balance and adverse outcomes in critically ill and postoperative patients is well-established.
Recent trials (CLASSIC and CLOVERS) haven’t shown significant differences between restrictive and liberal fluid resuscitation, emphasizing the importance of personalized approaches.
The concept of “de-resuscitation” or active fluid removal during recovery has gained traction. Patients with LV diastolic dysfunction (LVDD) and elevated LV filling pressure may benefit from early de-resuscitation to alleviate pulmonary congestion.
Non-invasive assessments, including Critical Care Echocardiography, Lung Ultrasound (LUS), and Venous Excess UltraSound (VExUS), aid in evaluating congestion.
The feasibility of fluid removal targeting a negative fluid balance, assessed through a holistic approach, including point-of-care ultrasound and other clinical parameters, should be considered early in the recovery phase.
Conclusions
The study of left ventricular diastolic function (LVDD) in the intensive care unit has shown an association with poor outcomes.
A proactive and multi-faceted approach is crucial for managing critically ill patients with LVDD. We propose the CHEOPS bundle, encompassing Chest Ultrasound (CCE and LUS), Hemodynamics considerations, Optimization of mechanical ventilation and pulmonary circulation, Stabilization, and personalized fluid removal targeting negative fluid balance.
Although the effectiveness of dedicated LVDD management in improving outcomes requires further research, screening for LV diastolic function in all ICU patients is recommended.
Source: Sanfilippo, Filippo, et al. “The “CHEOPS” bundle for the management of Left Ventricular Diastolic Dysfunction in critically ill patients: an experts’ opinion.” Anaesthesia Critical Care & Pain Medicine (2023): 101283.