Continuous right ventricular end diastolic volume and right ventricular ejection fraction during liver transplantation: a multicenter study

Use of Transesophageal Echocardiography for Liver Transplantation: A Global Comparison of Practice From the ILTS, SATA, and LICAGE

BACKGROUND

Anesthesiologists frequently use intraoperative transesophageal echocardiography (TEE) to aid in the diagnosis and management of hemodynamic problems during liver transplantation (LT). Although the use of TEE in US centers continues to increase, data regarding international use are lacking.

METHODS

This prospective, global, survey-based study evaluates international experience with TEE for LT. Responses from 252 LT (105 US and 147 non-US) centers representing 1789 anesthesiologists were analyzed.

RESULTS

Routine use of TEE in the United States has increased in the last 5 y (from 37% to 47%), but only 21% of non-US LT anesthesiologists use TEE routinely. Lack of training (44% US versus 70% non-US) and equipment (9% non-US versus 34% US) were cited as obstacles. Most survey participants preferred not to perform a complete cardiac examination but rather use only 6 of 11 basic views. Although non-US LT anesthesiologists more frequently had additional clinical training than their US counterparts, they had less TEE experience (13% versus 44%) and less frequently, TEE certification (22% versus 35%). Most LT anesthesiologists agreed that TEE certification is essential for proficiency. Of all respondents, 89% agreed or strongly agreed that TEE provides valuable information needed for immediate clinical decision-making, and >86% agreed or strongly agreed that that information could not be derived from other sources.

CONCLUSIONS

The use of TEE for LT surgery in the US LT centers is currently higher compared with non-US LT centers. This may become a standard monitoring modality during LT in the near future.

An overview of unresolved issues in the perioperative management of liver transplant patients

Over the past decade, the field of solid organ transplantation has undergone significant changes, with some of the most notable advancements occurring in liver transplantation. Recent years have seen substantial progress in preoperative patient optimization protocols, anesthesia monitoring, coagulation management, and fluid management, among other areas. These improvements have led to excellent perioperative outcomes for all surgical patients, including those undergoing liver transplantation. In the last few decades, there have been numerous publications in the field of liver transplantation, but controversies related to perioperative management of liver transplant recipients persist. In this review article, we address the unresolved issues surrounding the anesthetic management of patients scheduled for liver transplantation.

Evaluation of right ventricular function during liver transplantation with transesophageal echocardiography

BACKGROUND

The pathophysiology of advanced liver cirrhosis may induce alterations in the circulatory system that may be challenging for the anesthesiologist to manage intraoperatively, and perioperative cardiovascular events are associated with worse outcomes in cirrhotic patients undergoing liver transplantation. It remains controversial whether right ventricular function is impaired during this procedure. Studies using transesophageal echocardiography for quantitative analysis of the right ventricle remain scarce in this setting, yielding conflicting results. The aim of this study was to perform a quantitative assessment of right ventricular function with two parameters derived from transesophageal echocardiography during liver transplantation.

METHODS

Nineteen adult patients of both genders undergoing liver transplantation were evaluated in this observational study. The exclusion criteria were age under 18 or above 65 years old, fulminant hepatic failure, hepatopulmonary syndrome, portopulmonary hypertension, cardiopulmonary disease, and contraindications to the transesophageal echocardiogram. Right ventricular function was assessed at five stages during liver transplantation: baseline, hepatectomy, anhepatic, postreperfusion, and closure by measuring tricuspid annular plane systolic excursion and right ventricular fractional area change obtained with transesophageal echocardiography.

RESULTS

Right ventricular function was found to be normal throughout the procedure. The tricuspid annular plane systolic excursion showed a trend toward a decrease in the anhepatic phase compared to baseline (2.0 ± 0.9 cm vs. 2.4 ± 0.7 cm; P = 0.24) but with full recovery after reperfusion. Right ventricular fractional area change remained nearly constant during all stages studied (minimum: 50% ± 10 at baseline and anhepatic phase; maximum: 56% ± 12 at postreperfusion; P = 0.24).

CONCLUSIONS

Right ventricular function was preserved during liver transplantation at the time points evaluated by two quantitative parameters derived from transesophageal echocardiogram.

The Prognostic Role of Right Ventricular Stroke Work Index during Liver Transplantation

Right heart-associated hemodynamic parameters including intraoperative pulmonary vascular resistance (PVR) were reported to be associated with patient survival after liver transplantation. We investigated whether intraoperative stroke work indexes of both ventricles could have a better prognostic value than PVR. We reviewed 683 cases at a tertiary care academic medical center. We collected intraoperative variables of baseline central venous pressure, baseline right ventricle end-diastolic volume, mixed venous oxygen saturation, intraoperative PVR and right and left ventricular stroke work indexes. Time-weighted means or area under the curve of intraoperative right and left ventricular stroke work indexes were calculated as exposure variables. One-year all-cause mortality or graft failure was our primary outcome. Cox proportional hazard regression analysis was performed to evaluate the association between exposure variables and one-year all-cause mortality or graft failure. Kaplan–Meier survival curve analysis of our primary outcome was performed for different time-weighted mean ventricular stroke work index groups. Cubic spline curve analysis was performed to evaluate the linear relationship between our exposure variables and primary outcome. Time-weighted mean right ventricular stroke work index was significantly associated with one-year all-cause mortality or graft failure (hazard ratio 1.21, 95% confidence interval (CI) 1.12–1.36, p < 0.001). However, there was no significant association between time-weighted mean left ventricular stroke work index, time-weighted mean PVR, PVR at the end of surgery and one-year mortality. Area under the curve of right ventricular stroke work index was also significantly associated with one-year mortality or graft failure (hazard ratio 1.24, 95% CI 1.15–1.37, p < 0.001). Kaplan–Meier survival curve analysis showed a significant difference in the survival between different mean right ventricular stroke work index groups (Log-rank test: p = 0.002). Cubic spline function curve showed the gradual increase in the risk of mortality with a positive slope with time-weighted mean right ventricular stroke work index. In conclusion, intraoperative elevated right ventricular stroke work index was significantly associated with poor patient or graft survival after liver transplantation. Intraoperative right ventricular stroke work index could be an intraoperative hemodynamic goal and prognostic marker for mortality after liver transplantation.

Intraoperative Hemodynamic Parameters and Acute Kidney Injury After Living Donor Liver Transplantation

BACKGROUND

Acute kidney injury (AKI) after living donor liver transplantation (LDLT) is associated with increased mortality. We sought to identify associations between intraoperative hemodynamic variables and postoperative AKI.

METHODS

We retrospectively reviewed 734 cases of LDLT. Intraoperative hemodynamic variables of systemic and pulmonary arterial pressure, central venous pressure (CVP), and pulmonary artery catheter-derived parameters including mixed venous oxygen saturation (SvO2), right ventricular end-diastolic volume (RVEDV), stroke volume, systemic vascular resistance, right ventricular ejection fraction, and stroke work index were collected. Propensity score matching analysis was performed between patients with (n = 265) and without (n = 265) postoperative AKI. Hemodynamic variables were compared between patients with AKI, defined by Kidney Disease Improving Global Outcomes criteria, and those without AKI in the matched sample.

RESULTS

The incidence of AKI was 36.1% (265/734). Baseline CVP, baseline RVEDV, and SvO2 at 5 minutes before reperfusion were significantly different between patients with and without AKI in the matched sample of 265 pairs. Multivariable logistic regression analysis revealed that baseline CVP, baseline RVEDV, and SvO2 at 5 minutes before reperfusion were independent predictors of AKI (CVP per 5 cm H2O increase: odds ratio [OR], 1.20; 95% confidence interval [CI], 1.09-1.32; SvO2: OR, 1.45; 95% CI, 1.27-1.71; RVEDV: OR, 1.48; 95% CI, 1.24-1.78).

CONCLUSIONS

The elevated baseline CVP, elevated baseline RVEDV after anesthesia induction, and decreased SvO2 during anhepatic phase were associated with postoperative AKI. Prospective trials are required to evaluate whether the optimization of these variables may decrease the risk of AKI after LDLT.

Further Hemodynamic Insight Into Patients Undergoing Liver Transplantation: A Preliminary Report on Cardiac Power Index

INTRODUCTION

The aim of this retrospective study was to evaluate any relationship between cardiac power index (CPI) and preload indexes during liver transplantation (LT).

METHODS

Thirty-three patients with normal preoperative cardiac evaluation undergoing LT were included. Anesthesia management was standardized. Monitoring included continuous cardiac output determination by pulmonary artery catheter. CPI was calculated throughout LT by using the following standard formula: Mean Arterial Pressure [mm Hg] × Cardiac Index [L/min/m²] × k, where k = 0.0022. A logistic regression to determine which preload indexes predicted an adequate CPI (≥ 0.4 watt/m²) was performed. Postregression analysis was carried out to calculate a cutoff of right ventricle end diastolic volume index (RVEDVI) able to guarantee an adequate CPI after establishing a sensitivity >0.9. The area under receiver operating characteristic curve (AUC) was also run separately for patients with a Model for End-Stage Liver Disease (MELD) score < or ≥ 25 to establish an accurate level of prediction in these subgroups (post-hoc analysis).

RESULTS

Logistic regression showed that RVEDVI was the only predictor of CPI (AUC = 0.81). A cutoff value for RVEDVI of 105 mL/m² was found (sensitivity = 90.5%; specificity = 50%). RVEDVI predicted CPI with moderate accuracy (AUC = 0.80) in patients with MELD < 25 (n = 25), whereas the prediction was highly accurate (AUC = 0.96) in patients with MELD ≥ 25 (n = 8).

CONCLUSION

An RVEDVI = 105 mL/m² can be considered a valid cutoff to perform a fluid challenge to optimize preload during LT. Sicker recipients (with MELD ≥ 25) could exhibit less tolerance to preload reduction, proven by a decrease of CPI below the minimum value considered safe (0.40 watt/m²).

Assessment of fluid responsiveness by inferior vena cava diameter variation in post-pneumonectomy patients

AIM

First, the inferior vena cava dilatation index (DIVC) was measured by ultrasound, and then the reliability of DIVC as an indicator to predict volume responsiveness in patients undergoing mechanical ventilation after pneumonectomy was evaluated.

METHODS

Pulse indicator continuous cardiac output (Picco) as gold standard was performed to sedated mechanically ventilated post-pneumonectomy patients in intensive care unit of Nanjing Thoracic Hospital from August 2014 to December 2016. Meanwhile, ultrasound measurement to inferior vena cava (IVC) diameter at the end inspiration (Dmax ) and the end of expiration (Dmin ) was performed. DIVC = (Dmax  - Dmin )/Dmin . Above values were recorded at baseline and then after fluid resuscitation challenge (7 mL/kg hydroxyethyl starch). An increase in cardiac index of more than 15% was used as the standard for fluid responsiveness. Patients were divided into responsive group and non-responsive group. A receiver operating characteristic (ROC) curve was then used to determine the sensitivity and specificity of DIVC in predicting fluid responsiveness after pneumonectomy.

RESULTS

Eighteen patients were enrolled. 10 patients were divided into responsive group and eight in non-responsive group. DIVC in responsive group was significantly higher than in non-responsive group (P < 0.01). By setting DIVC ≥ 15% as a measure of fluid responsiveness, sensitivity was 81.8% and specificity was 85.7%.

CONCLUSION

DIVC is a reliable indicator of capacity responsiveness in mechanically ventilated post-pneumonectomy patients.

Evaluation of New Calibrated Pulse-Wave Analysis (VolumeViewTM/EV1000TM) for Cardiac Output Monitoring Undergoing Living Donor Liver Transplantation

Background

Intrapulmonary thermodilution technique using a pulmonary artery catheter is widely used for measuring cardiac output (CO) in patients undergoing liver transplantation. However, its invasiveness and associated complications have led to an interest in less invasive modalities. Thus, we aimed to evaluate whether the new calibrated pulse-wave analysis method monitoring (VolumeView^TM/EV1000^TM) is interchangeable with intrapulmonary thermodilution technique.

Methods

Twenty-eight patients undergoing living donor liver transplantation were enrolled in this prospective observational study. COs were recorded automatically by the two devices and compared simultaneously at 10-minute intervals. The agreement of absolute CO values and the tracking ability of CO changes trends were compared. A Bland-Altman analysis with percentage errors and concordance rate for trend analysis using both a 4-quadrant plot and a polar plot were performed on the data.

Results

A total of 375 paired datasets from 25 patients were included in analysis. COs measured by intrapulmonary thermodilution ranged from 3.8–13.7 L/min. The mean CO difference between the two techniques was 0.57 L/min, and the 95% limits of agreement were -0.98 L/min to 2.12 L/min with a percentage error of 42.3%. The percentage errors in the dissection, anhepatic, and reperfusion phase were 30.5%, 31.7%, and 27.4%, respectively. The concordance rate between the two techniques was 78.4%.

Conclusion

The calibrated pulse-wave analysis and intrapulmonary thermodilution failed to show acceptable interchangeability in terms of both estimating CO and tracking CO changes during living donor liver transplantation.

Ultrasonographic measurements of the inferior vena cava variation as a predictor of fluid responsiveness in patients undergoing anesthesia for surgery

BACKGROUND

Both hypovolemia and hypervolemia are connected with increased morbidity and mortality in the treatment and prognosis of patients. An accurate assessment of volume state allows the optimization of organ perfusion and oxygen supply. Recently, ultrasonography has been used to detect hypovolemia in critically ill patients and perioperative patients. The objective of our study was to assess the correlation between inferior vena cava (IVC) variation obtained with ultrasound and stroke volume variation (SVV) measured by the Vigileo/FloTrac monitor, as fluid responsiveness indicators, in patients undergoing anesthesia for surgery.

METHODS

Forty patients (American Society of Anesthesiologists grades I and II) scheduled for elective gastrointestinal surgery were enrolled in our study. After anesthesia induction, 6% hydroxyethyl starch solution was administered to patients as an intravenous (IV) fluid. The IVC diameters were measured with ultrasonography. SVV and stroke volume index (SVI) were obtained from the Vigileo monitor. All data were collected both before and after fluid challenge.

RESULTS

Forty patients underwent IVC sonographic measurements and SVV calculation. After fluid challenge, mean arterial pressure, central venous pressure, SVI, and IVC diameters increased significantly, whereas SVV decreased markedly. The correlation coefficient between the increase in SVI and the baseline of IVC variation after an IV fluid was 0.710, and receiver operating characteristic (ROC) curve was 0.85. The correlation coefficient between the increase in SVI and the baseline of SVV was 0.803 with an ROC curve of 0.93. Central venous pressure had no significant correlation with SVI.

CONCLUSIONS

Our data show that IVC variation and SVV proved to be reliable predictors of fluid responsiveness in patients undergoing anesthesia for surgery with mechanical ventilation.

Corrected right ventricular end-diastolic volume and initial distribution volume of glucose correlate with cardiac output after cardiac surgery

PURPOSE

Appropriate adjustment of cardiac preload is essential to maintain cardiac output (CO), especially in patients after cardiac surgery. This study was intended to determine whether index of right ventricular end-diastolic volume (RVEDVI), corrected RVEDVI using ejection fraction (cRVEDVI), index of initial distribution volume of glucose (IDVGI), or cardiac filling pressures are correlated with cardiac index (CI) following cardiac surgery in the presence or absence of arrhythmias.

METHODS

Eighty-six consecutive cardiac surgical patients were studied. Patients were divided into two groups: the non-arrhythmia (NA) group (n = 72) and the arrhythmia (A) group (n = 14). Three sets of measurements were performed: on admission to the ICU and daily on the first 2 postoperative days. The relationship between each cardiac preload variable and cardiac index (CI) was evaluated. A p value less than 0.05 indicated statistically significant differences.

RESULTS

Each studied variable was not different between the two groups immediately after admission to the ICU. cRVEDVI had a linear correlation with CI in both group (NA group: r = 0.67, n = 216, p < 0.001; A group: r = 0.77, n = 42, p < 0.001), but RVEDVI had a poor correlation with CI (NA group: r = 0.27, n = 216, p < 0.001; A group: r = 0.19, n = 42, p = 0.036). IDVGI had a linear correlation with CI (NA group: r = 0.49, n = 216, p < 0.001; A group: r = 0.61, n = 42, p < 0.001), Cardiac filling pressures had no correlation with CI.

CONCLUSION

Our results demonstrated that cRVEDVI and IDVGI were correlated with CI in the presence or absence of arrhythmias. cRVEDVI and IDVGI have potential as indirect cardiac preload markers following cardiac surgery.

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.

Perioperative monitoring in liver transplant patients

Liver transplant (LT) is a major surgical undertaking involving major fluid shifts, hemodynamic instability and metabolic derangements in a patient with preexisting liver failure and multisystemic derangements. Monitoring and organ support initiated in the preoperative phase is continued intraoperatively and into the postoperative phase to ensure an optimal outcome. As cardiovascular events are the leading cause of non-graft related death among LT recipients, major emphasis is placed on cardiovascular monitoring. The other essential monitoring are the continuous assessment of coagulapathy, extent of metabolic derangements, dyselectrolytemis and intracranial pressure monitoring in patients with fulminant hepatic failure. The type and extent of monitoring differs with need according to preexisting child status of the patient and the extent of systemic derangements. It also varies among transplant centers and is mainly determined by individual or institutional practices.

Stroke volume variation derived by arterial pulse contour analysis is a good indicator for preload estimation during liver transplantation

BACKGROUND

Accurate determination of preload during liver transplantation is essential. Continuous right ventricular end diastolic volume index (RVEDVI) has been shown to be a better preload indicator during liver transplantation than the filling pressures. However, recent evidence has shown that dynamic variables, in this case stroke volume variation (SVV), are also good indicators of preload responsiveness. In this study, we evaluated the correlation between SVV, which we derived from arterial pulse contour analysis and RVEDVI.

METHODS

In this study, we looked for possible relationships between SVV obtained through FloTrac/Vigileo monitor, central venous pressure (CVP), pulmonary arterial occlusion pressure (PAOP), and RVEDVI in 30 patients undergoing liver transplantation. Measurements were taken at 11 defined points during different phases across liver transplantation. Each set of measurement was taken during a steady state, which means at least 15 minutes elpased after any changes occured in either the infusion rate of catecholamines or ventilator settings. Pearson's test was used for correlation estimation.

RESULTS

There was a statistically significant (P<.01) relationship between SVV and RVEDVI with a correlation coefficient of -0.87. The correlations between CVP (r=0.42), PAOA (r=0.46), and RVEDVI were less strong.

CONCLUSION

We conclude that SVV is a good indicator for preload estimation during liver transplantation. A higher SVV value is associated with a more hypovolemic fluid status.

The impact of portopulmonary hypertension on intraoperative right ventricular function of living donor liver transplant recipients

BACKGROUND

Portopulmonary hypertension (PPH) burdens a right ventricle (RV) already exposed to physiologic stress during liver transplantation. The magnitude of the impact of PPH on RV function, especially early reperfusion, has not been evaluated adequately by prospective controlled trials. In this study, we prospectively quantified the impact of PPH on the RV function in living donor liver transplant recipients.

METHODS

Twenty patients undergoing living donor liver transplant were stratified based on mean pulmonary artery pressure (mPAP) into a control group (mPAP <25 mm Hg) and a PPH group (mPAP ≥25 mm Hg). Standard anesthetic technique and monitoring were used. Fiberoptic pulmonary artery catheters enabled to measure RV ejection fraction (RVEF) were used. Hemodynamics were recorded after induction of anesthesia, the end of hepatectomy, before portal unclamping, 5 and 30 minutes after reperfusion, and at skin closure.

RESULTS

The PPH group had significantly lower RVEF, stroke volume, and higher central venous pressure and RV end-diastolic volume index after portal unclamping versus the controls. Pulmonary vascular resistance index and mPAP were significantly higher throughout the operation in the PPH group, but RV stroke work index did not differ significantly between groups. RVEF was significantly reduced in the PPH group after reperfusion compared with baseline, but the control group did not experience such a reduction.

CONCLUSIONS

Mild to moderate PPH was associated with reduced RVEF during liver transplantation, especially after reperfusion, likely because of a reduced RV contractile reserve in PPH patients. This reduction in RVEF was clinically well tolerated by patients with mild to moderate PPH.

[Anesthesia in the patient with impaired liver function]

We review information on impaired liver function, focusing on concepts relevant to anesthesia and postoperative recovery. The effects of impaired function are analyzed by systems of the body, with attention to the complications the patient with liver cirrhosis may develop according to type of surgery. Approaches to correcting coagulation disorders in the cirrhotic patient are particularly controversial because an increase in volume may be a factor in bleeding owing to increased portal venous pressure and imbalances in the factors that favor or inhibit coagulation. Perioperative morbidity and mortality correlate closely to Child-Pugh class and the score derived from the model for end-stage liver disease (MELD). Patients in Child class A are at moderate risk and surgery is therefore not contraindicated. Patients in Child class C or with a MELD score over 20, on the other hand, are at high risk and should not undergo elective surgical procedures. Abdominal surgery is generally considered to put patients with impaired liver function at high risk because it causes changes in hepatic blood flow and increases intraoperative bleeding because of high portal venous pressures.

Optimizing cost-effectiveness in perioperative care for liver transplantation: a model for low- to medium-income countries

Although liver transplantation (LT) is a highly effective treatment, it has been considered too costly for publicly funded health systems in many countries with low to medium average incomes. However, with economic growth and improving results, some governments are reconsidering this position. Cost-effectiveness data for LT are limited, especially in perioperative care, and the techniques and costs vary widely between centers without overt differences in outcomes. Anesthesiologists working in new programs find it difficult to determine which modalities are essential, which are needed only in exceptional circumstances, and which may be omitted without effects on outcomes. We investigated key elements of preoperative evaluations, intraoperative management, and early postoperative care that might significantly affect costs in order to develop a best-value approach for new programs in resource-limited health systems. We identified all modalities of care commonly used in anesthesia and perioperative care for adult LT along with their costs. Those considered to be universally accepted as minimum requirements for safe care were excluded from the analysis, and so were those considered to be safe and low-cost, even when evidence of efficacy was lacking. The remaining items were, therefore, those with uncertain or context-restricted value and significant costs. A systematic review of the published evidence, practice surveys, and institutional guidelines was performed, and the evidence was graded and summarized. With respect to costs and benefits, each modality was then cited as strongly recommended, recommended or optional, or no recommendation was made because of insufficient evidence. Sixteen modalities, which included preoperative cardiovascular imaging, venovenous bypass, pulmonary artery catheterization, high-flow fluid warming devices, drug therapies for hemostasis, albumin, cell salvage, anesthetic drugs, personnel (staffing) requirements, and early extubation, were assessed. Only high-flow fluid warming was strongly recommended. The recommended modalities included preoperative echocardiography, cell salvage, tranexamic acid and early extubation. Six others were rated optional, and there was insufficient evidence for 5 modalities. We conclude that some costly techniques and treatments can be omitted without adverse effects on outcomes.

A retrospective case-control study of intraoperative cardiac dysfunction in elderly patients (≥60 years) undergoing live donor liver transplantation

BACKGROUND

The age range of patients accepted for the orthotopic liver transplantation (OLT) has widened. Concerns have arisen, therefore, about the ability of the hearts of elderly patients to manage these stressful conditions. The aim of this study was to investigate the preoperative echocardiographic findings and the intraoperative cardiac dysfunction among elderly cirrhotic recipients undergoing live donor OLT.

METHODS

In this retrospective case-control study we evaluated clinical data, echocardiography, and intraoperative right-sided heart hemodynamic measurements from 2007 and 2009 among 56 recipients aged at least 60 years who were matched for gender and the severity of cirrhosis. Intraoperative cardiac dysfunction was defined as a decreased left ventricular stroke work index despite an increase in right ventricular end diastolic volume index (RVEDVI) or pulmonary artery occlusion pressure (PAOP). We compared measurements at predetermined times during the anhepatic and neohepatic periods with those at baseline.

RESULTS

Older recipients (mean, 63 years; range, 60-69) showed significantly reduced early diastolic annular velocity (E'), early maximal ventricular filling velocity (E)/late filling velocity (A) ratio, and increased A on echocardiography versus younger recipients (mean 48 years; range, 31-56). We observed negative correlation between age and E' (r = -0.44; P < .001) and a positive correlation between age and E/E' (r = 0.31; P < .01). The incidence of intraoperative cardiac dysfunction did not differ between case and control groups with an increase of RVEDVI (11.4% vs 10.6%) or PAOP (27.2% vs 25.0%) during the anhepatic and neohepatic periods. A higher proportion of older recipients needed inotropic agents during OLT (60.7% vs 39.3%; P = .04).

CONCLUSIONS

OLT patients of ar least 60 years of age may not show a greater incidence of cardiac dysfunction during OLT versus younger ones, although older recipients showed reduced diastolic function and more frequently required inotropic support.

Inferior vena cava distensibility as a predictor of fluid responsiveness in patients with subarachnoid hemorrhage

BACKGROUND

The objective of our study is to assess the reliability of the distensibility of the inferior vena cava (dIVC), as measured by ultrasound, as an indicator of fluid responsiveness in patients with subarachnoid hemorrhage.

METHODS

We enrolled 29 adult patients requiring advanced hemodynamic monitoring, sedation, and mechanical ventilation. Inferior vena cava diameter was measured during a single mechanical breath. The dIVC was calculated as (the diameter of the inferior vena cava on inspiration-the diameter on expiration)/the diameter on expiration. All the hemodynamic parameters were collected at baseline and after a fluid challenge (7 ml/kg) with 6% hydroxyethyl starch. A 15% increase of cardiac index was the standard criterion used to differentiate patients with and without a response to fluid therapy.

RESULTS

Apart from stroke volume variation (SVV) and dIVC, which were significantly higher in fluid responders (17 patients), the other baseline characteristics did not differ significantly between groups (responders versus non-responders). Significant changes in hemodynamic parameters after volume load were observed only in fluid responders. The area under the ROC curve was 0.779 (95% confidence interval 0.587-0.911) for SVV and 0.902 (95% confidence interval 0.733-0.979, P = NS) for dIVC. Central venous pressure was a less reliable indicator of fluid responsiveness than dIVC. A dIVC value of >16% yielded the most favorable balance of test characteristics, with 70.59% sensitivity and 100% specificity. There was a trend toward a lower incidence of delayed ischemic lesions in fluid responders (11.7 vs. 25%, P = NS).

CONCLUSION

dIVC proved to be a reliable predictor of fluid responsiveness in ICU patients with subarachnoid hemorrhage.

Prospective evaluation of intraoperative hemodynamics in liver transplantation with whole, partial and DCD grafts

The interaction of systemic hemodynamics with hepatic flows at the time of liver transplantation (LT) has not been studied in a prospective uniform way for different types of grafts. We prospectively evaluated intraoperative hemodynamics of 103 whole and partial LT. Liver graft hemodynamics were measured using the ultrasound transit time method to obtain portal (PVF) and arterial (HAF) hepatic flow. Measurements were recorded on the native liver, the portocaval shunt, following reperfusion and after biliary anastomosis. After LT HAF and PVF do not immediately return to normal values. Increased PVF was observed after graft implantation. Living donor LT showed the highest compliance to portal hyperperfusion. The amount of liver perfusion seemed to be related to the quality of the graft. A positive correlation for HAF, PVF and total hepatic blood flow with cardiac output was found (p = 0.001). Portal hypertension, macrosteatosis >30%, warm ischemia time and cardiac output, independently influence the hepatic flows. These results highlight the role of systemic hemodynamic management in LT to optimize hepatic perfusion, particularly in LDLT and split LT, where the highest flows were registered.

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.

Perioperative considerations in patients with cirrhotic cardiomyopathy

PURPOSE OF REVIEW

This review aims to identify specific criteria for cirrhotic cardiomyopathy, examine the correlation with perioperative adverse outcomes and explore options for hemodynamic monitoring.

RECENT FINDINGS

Cirrhotic cardiomyopathy is characterized by an increase in cardiac output, blunted systolic contractile response to stress, diastolic dysfunction and electrophysiological abnormalities. Adverse events due to cirrhotic cardiomyopathy are not as well characterized, but evidence suggests that some cardiovascular complications during surgery and in the postoperative period are caused by an impaired response to physiological stress. New developments in hemodynamic monitoring using not only thermodilution technology provide more reliable information about cardiac performance than pressure-derived measures. Transesophogeal echocardiography also offers the physician new information including the ability to visualize heart structures, shape, and function.

SUMMARY

To detect cirrhotic cardiomyopathy, physicians must conduct a systematic examination of the patient. Overt manifestations of cirrhotic cardiomyopathy often only become evident after a patient is exposed to physiological or drug-induced stress. Appropriate hemodynamic monitoring is a cornerstone in the perioperative management of cirrhotic patients.

Effects of on-pump and off-pump coronary artery bypass grafting on left ventricular relaxation and compliance: a comprehensive perioperative echocardiography study

AIMS

The short-term effect of coronary artery bypass grafting (CABG) on diastolic function is only moderately investigated. Furthermore, it remains unknown whether avoidance of cardioplegic arrest by an off-pump CABG procedure has advantages over on-pump procedure regarding diastolic relaxation and compliance. We investigated whether components of diastolic function would be improved the day after CABG depending on the type of the surgical procedure.

METHODS AND RESULTS

Spontaneously breathing on-pump (n = 20) and off-pump CABG (n = 12) patients underwent a comprehensive transthoracic echocardiography examination the day before and the day after elective CABG, including transmitral and pulmonary vein flow parameters, colour M-mode flow propagation velocity (Vp) and tissue Doppler assessment of the average mitral annulus diastolic velocity (Em). Isovolumic relaxation and E-wave deceleration time were corrected for heart rate (IVRTcHR and DTcHR). Left ventricular (LV) relaxation time (τ) and LV operating stiffness (LVOS) were calculated. Overall and independent from operation type and preload, CABG decreased IVRTcHR (107 ± 20 vs. 93 ± 15 ms) (P < 0.01) and τ (54 ± 10 vs. 45 ± 10 ms) (P < 0.01), increased Vp (49 ± 22 vs. 75 ± 37 cm/s) (P < 0.01), and increased Em (6.6 ± 2.0 vs. 7.3 ± 1.3 cm/s, P = 0.06), indicating improved relaxation. LVOS increased (0.13 ± 0.06 vs. 0.22 ± 0.05 mmHg/mL) (P < 0.01), compatible with an impaired compliance. A similar improvement in relaxation and impairment in compliance were observed in both groups.

CONCLUSION

Myocardial relaxation improved the day after CABG irrespective of the use of cardiopulmonary bypass with cardioplegic arrest. Impairment in compliance could not be prevented by the avoidance of cardioplegia.

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.