Bedside assessment of left atrial pressure in critical care: a multifaceted gem

Prediction of the ideal length of insertion to monitor left atrial pressures in pediatric open-heart surgery: a retrospective cohort study

BACKGROUND

Monitoring the left atrial pressures (LAP) is an important perioperative management tool for maintaining adequate cardiac output. However, incorrect placement of the LAP-monitoring catheter tip often leads to inherent risk. This study aimed to evaluate the length of the LAP catheter in pediatric open-heart surgery and devise a simple formula to predict the ideal length of insertion based on correlated demographic and clinical characteristics.

METHODS

We conducted a retrospective clinical cohort study involving 79 infant patients aged ≤ 1 year who underwent open-heart surgery and right internal jugular vein (RIJV) catheterization to monitor the LAP. Pearson correlation coefficient and multiple regression analysis were employed to determine the association between the optimal depth and patient characteristics. In the variable selection stage, Least Absolute Shrinkage and Selection Operator (LASSO) regression was utilized to select the most valuable variables as candidates for subsequent multiple regression analysis. Then a simple formula was derived to predict the ideal depth for the LAP measurement.

RESULTS

The participants consisted of 50 (63.3%) males and 29 (36.7%) females. Among them, 10 patients (12.7%) were preterm. The average age was 4.4 months; the average weight was 5.5 kg, and the average height was 60.5 cm. Height, body surface area (BSA), weight, age, and head circumference were strongly associated with the ideal length of the catheter. In the LASSO regression analysis, height and weight had the highest correlation coefficients. In the multiple regression model, only height showed a significant effect (P < 0.001). Consequently, we developed a new height-based formula: L (cm) = 5 + 0.1 × height (cm). The proportion of optimal depth determined by the new simplified formula was 88.6%.

CONCLUSIONS

Height was identified as the most significant individual predictor of ideal length in this study. The newly developed formula, L = 5.0 + 0.1 × height (cm), is feasible and can be utilized to determine the optimal depth of the catheter to monitor the LAP via RIJV during pediatric open-heart surgery.

Left Atrial Hemodynamics and Clinical Utility in Heart Failure

Comprehensive knowledge of the left atrium (LA) and its pathophysiology has emerged as an important clinical and research focus in the heart failure (HF) arena. Although studies on HF focusing on investigating left ventricular remodeling are numerous, those on atrial structural and functional changes have received comparatively less attention. Studies on LA remodeling have recently received increasing attention, and LA pressure (LAP) has become a novel target for advanced monitoring and is a potential therapeutic approach for treating HF. Various devices specifically designed for the direct measurement of LAP have been developed to optimize HF treatment by reducing LAP. This review focuses on LA hemodynamic monitoring and effective LAP decompression.

Effect of volume infusion on left atrial strain in acute circulatory failure

BACKGROUND

Left atrial strain (LAS) is a measure of atrial wall deformation during cardiac cycle and reflects atrial contribution to cardiovascular performance. Pathophysiological significance of LAS in critically ill patients with hemodynamic instability has never been explored. This study aimed at describing LAS and its variation during volume expansion and to assess the relationship between LAS components and fluid responsiveness.

METHODS

This prospective observational study was performed in a French ICU and included patients with acute circulatory failure, for whom the treating physician decided to proceed to volume expansion (rapid infusion of 500 mL of crystalloid solution). Trans-thoracic echocardiography was performed before and after the fluid infusion. LAS analysis was performed offline. Fluid responsiveness was defined as an increase in velocity-time integral (VTI) of left ventricular outflow tract ≥ 10%.

RESULTS

Thirty-eight patients were included in the final analysis. Seventeen (45%) patients were fluid responders. LAS analysis had a good feasibility and reproducibility. Overall, LAS was markedly reduced in all its components, with values of 19 [15 - 32], -9 [-19 - -7] and - 9 [-13 - -5] % for LAS reservoir (LASr), conduit (LAScd) and contraction (LASct), respectively. LASr, LAScd and LASct significantly increased during volume expansion in the entire population. Baseline value of LAS did not predict fluid responsiveness and the changes in LAS and VTI during volume expansion were not significantly correlated.

CONCLUSIONS

LAS is severely altered during acute circulatory failure. LAS components significantly increase during fluid administration, but cannot be used to predict or assess fluid responsiveness.

The value of a dynamic echocardiographic approach to diastolic dysfunction in intensive care medicine

Diastolic dysfunction is an underestimated feature in the context of the critically ill setting and perioperative medicine. Advances in echocardiography, its noninvasive, safe and easy use, have allowed Doppler echocardiography to become a cornerstone for diagnosing diastolic dysfunction in clinical practice. The diagnosis of diastolic dysfunction and increased filling pressures is nevertheless complex. Using an echocardiographic assessment and the routine application of preload stress maneuvers during echocardiographic examination can help identify early stages of diastolic dysfunction leading to better management of patients at risk of acute heart decompensation in the perioperative period or during ICU stay.

Lung ultrasonography derived B-line scores as predictors of left ventricular end-diastolic pressure and pulmonary artery wedge pressure

BACKGROUND

Non-invasive assessment of elevated left ventricular end-diastolic pressure (LVEDP) and pulmonary artery wedge pressure (PAWP) in patients with heart diseases is challenging. Lung ultrasonography (LUS) is a promising modality for predicting LVEDP and PAWP.

METHODS

Fifty-seven stable ambulatory patients who underwent right and left heart catheterization were included. Following the procedures, LUS was performed in twenty-eight ultrasonographic zones, and the correlation between five different LUS derived B-line scores with LVEDP and PAWP was examined.

RESULTS

The B-line index correlated with LVEDP and PAWP, with coefficients of 0.45 (p = 0.006) and 0.30 (p = 0.03), respectively. B-line index showed an AUC of 0.76 for identifying LVEDP > 15 mmHg (p = 0.01) and an AUC of 0.73 for identifying PAWP > 15 mmHg (p = 0.008). Overall, scores performances were similar in predicting LVEDP or PAWP > 15 mmHg. A B-line index ≥ 28 was significantly associated with LVEDP > 15 mmHg (OR: 9.97) and PAWP > 15 mmHg (OR: 6.61), adjusted for age and indication for heart catheterization.

CONCLUSIONS

LUS derived B-line scores are moderately correlated with PAWP and LVEDP in patients with heart diseases. A B-line index ≥ 28 can be used to predict elevated LVEDP and PAWP with high specificity.

Pulmonary Arterial Hypertension in the Elderly: Peculiar Features and Challenges for a Proper Phenotyping Approach

(1) Introduction. Although pulmonary arterial hypertension (PAH) usually affects young people with a low cardiovascular risk profile, progressive epidemiologic changes have been providing a codified phenotype of elderly subjects with PAH and increased risk predictors for left heart disease. We therefore conducted a systematic review to describe the current knowledge and characteristics of elderly individuals with PAH and further insights concerning their prognostic outcomes and therapeutic response. (2) Methods. A search was conducted in PubMed, Embase, and Cochrane Library for publications evaluating the epidemiology, diagnostic work-up, and treatment of PAH in elderly subjects. (3) Among the 74 publications initially retrieved, 16 full-text articles were selected for the present systematic review. Compared to their younger counterparts, elderly individuals with PAH showed greater clinical deterioration, reduced exercise capacity, and worse prognostic outcomes, as well as less response to PAH-targeted therapy and higher rates of PAH drug discontinuation. (4) Conclusions. Demographic changes over time contributed to define a peculiar PAH phenotype in elderly patients, with an increased burden of cardiovascular comorbidities and distinctive features compared to young patients. Further investigations are needed in order to better clarify the nosologic criteria, and management in this subset population.

Mitral regurgitation in the critically ill: the devil is in the detail

Mitral regurgitation (MR) is common in the critically unwell and encompasses a heterogenous group of conditions with diverging therapeutic strategies. MR may present acutely with haemodynamic instability or more insidiously with failure to wean from mechanical ventilation. Critical illness is associated with marked physiological stress and haemodynamic changes that dynamically influence the severity and implication of MR. The expanding role of critical care echocardiography uniquely positions the intensivist to apply advanced bedside valvular assessment to recognise haemodynanically significant MR, manipulate and optimise cardiopulmonary physiology and identify patients requiring urgent cardiology and surgical referral. This review will consider common clinical scenarios, therapeutic strategies and the pearls and pitfalls of echocardiographic assessment and quantification in the critically unwell.