Continuous right ventricular end-diastolic volume in comparison with left ventricular end-diastolic area. Eur J Anaesthesiol. 2009;26:272-278. [PMID: 19276913 DOI: 10.1097/eja.0b013e328319be8e]

Transoesophageal echocardiography during liver transplantation

Liver transplantation (LT) has become the standard of care for patients with end stage liver disease. The allocation of organs, which prioritizes the sickest patients, has made the management of liver transplant candidates more complex both as regards their comorbidities and their higher risk of perioperative complications. Patients undergoing LT frequently display considerable physiological changes during the procedures as a result of both the disease process and the surgery. Transoesophageal echocardiography (TEE), which visualizes dynamic cardiac function and overall contractility, has become essential for perioperative LT management and can optimize the anaesthetic management of these highly complex patients. Moreover, TEE can provide useful information on volume status and the adequacy of therapeutic interventions and can diagnose early intraoperative complications, such as the embolization of large vessels or development of pulmonary hypertension. In this review, directed at clinicians who manage TEE during LT, we show why the procedure merits a place in challenging anaesthetic environment and how it can provide essential information in the perioperative management of compromised patients undergoing this very complex surgical procedure.

Changes in brain natriuretic peptide are correlated with changes in global end-diastolic volume index

BACKGROUND AND OBJECTIVE

It is believed that the stretch of cardiomyocytes is the most important stimulus of brain natriuretic peptide (BNP) release; however, its correlation with volume status represented by global end diastolic volume index (GEDVI) is less well established. The study aimed to investigate the correlation between the changes in BNP and the changes in GEDVI measured with transpulmonary thermodilution technique.

METHODS

Critically ill patients requiring hemodynamic monitoring (PiCCO system) in a tertiary 18-bed intensive care unit were prospectively enrolled. Hemodynamic variables were measured simultaneously with blood sampling for BNP concentration. Correlations between changes in BNP and changes in GEDVI were tested using pairwise correlation analysis.

RESULTS

A total of 46 patients were included in the study. BNP level (median 4,602 pg/mL; IQR 1,988 to 12,439 pg/mL) was markedly elevated in the study population, but was not correlated with GEDVI (rho=-0.09, P=0.56). The changes in BNP (ΔBNP) showed significant correlation with changes in GEDVI (ΔGEDVI) (Figure 2; rho=0.52, P<0.01). Variables including Age (r=0.43, P=0.002), serum creatinine (r=0.36, P=0.012) and cardiac index (CI) (r=-0.35, P=0.016) were also significantly correlated with logBNP. Other variables such as APACHE II score, central venous pressure (CVP), heart rate (HR), intrathoracic blood volume (ITBVI), extravascular lung water (EVLWI) and systemic vascular resistance index (SVRI) were not significantly correlated with logBNP.

CONCLUSIONS

Changes in BNP concentrations are correlated with changes in GEDVI and serial measurements of BNP concentrations may be a useful tool for monitoring volume status.

Is stroke volume variation a useful preload index in liver transplant recipients? A retrospective analysis

BACKGROUND

The right ventricular end-diastolic volume index (RVEDVI) is a good indicator of preload in patients undergoing liver transplantation. Although dynamic indices, such as stroke volume variation (SVV), have been used as reliable indicators in predicting fluid responsiveness, the evaluation of the relationship between SVV and direct preload status is limited. We investigated the relationship between SVV and RVEDVI, and tested the cutoff value of SVV to predict RVEDVI during liver transplantation.

METHODS

A total of 150 data pairs in 30 living donor liver transplant recipients were retrospectively investigated. Hemodynamic parameters, including SVV and RVEDVI were obtained from each patient at the 5 specific time points. Linear regression and receiver operating characteristic (ROC) curve analyses were performed.

RESULTS

The SVV significantly correlated with the RVEDVI (r = -0.616, P < 0.001). Cutoff values for the upper and lower tertiles of RVEDVI were 157 mL/m(2) and 128 mL/m(2), respectively. Tertile analysis indicated that upper tertile of RVEDVI had a significantly lower SVV than the middle tertile (median; 5% vs 8%, P < 0.05), and middle tertile of RVEDVI had a significantly lower SVV than the lower tertile (median; 8% vs 11%, P < 0.05). A 6% cutoff value of SVV estimated the upper tertile RVEDVI (>157 mL/m(2)) with the area under the curve of ROC curve of 0.832. A 9% cutoff value of SVV estimated the lower tertile RVEDVI (<128 mL/m(2)) with the area under the curve of ROC curve of 0.792.

CONCLUSION

SVV may be a valuable estimator of RVEDVI in patients undergoing liver transplantation.

Static measures of preload assessment

This article focuses on static methods for determining preload, specifically pressure and volumetric indices measured at the bedside. The underlying ventricular function will determine where the patient is located on Frank-Starling ventricular function curve and the patient's response to a fluid challenge. The proper interpretation and use of such measures, coupled with an understanding of their limitations and knowledge of alternative methods, is necessary to guide properly volume resuscitation in the critically ill.

Intraoperative hemodynamic monitoring during organ transplantation: what is new?

PURPOSE OF REVIEW

To highlight the recent developments in hemodynamic monitoring during liver and lung transplantation.

RECENT FINDINGS

Even though a consensus on intraoperative hemodynamic monitoring is still lacking, the most frequently monitoring tool used is the pulmonary artery catheter (PAC). The filling pressures are widely accepted as not being able to accurately define cardiac preload. On the contrary, the use of transesophageal echocardiography (TEE), although it is operator dependent and requires a prolonged training, is increasing during the intraoperative period to directly evaluate the cardiovascular function. New frontiers have been opened by the transpulmonary thermodilution: intrathoracic blood volume has been shown to have a better correlation with preload than the filling pressures. The advanced modified PAC permits evaluation of the right heart function and preload. Recently, right ventricular end diastolic volume has been shown to correlate better with preload than the filling pressures and also the left ventricular end diastolic area.

SUMMARY

The PAC still represents the most used intraoperative hemodynamic monitoring technique. TEE is increasing in popularity. Recent studies demonstrate that volumetric monitoring conducted with transpulmonary thermodilution and advanced volumetric PAC give good definition of preload and should be implemented in clinical practice.