Use of an Esophageal Echo-Doppler Device During Liver Transplantation: Preliminary Report

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).

Use of transesophageal Doppler as a sole cardiac output monitor for reperfusion hemodynamic changes during living donor liver transplantation: An observational study

Aims:

To report the use of transesophageal Doppler (TED), a minimally invasive cardiac output (COP) monitor, before, during and after reperfusion and study its effect on anesthetic management during living donor liver transplantation (LDLT).

Setting and Design:

A prospective observational study.

Methods:

A total of 25 consecutive recipients with a MELD score between 15 and 20 were enrolled. Data were recorded at baseline (TB); anhepatic phase (TA); and post-reperfusion — 1, 5, 10 and 30 minutes. Fluid therapy was guided by corrected flow time (FTc) of the TED. Packed red blood cells (RBCs) were only given when hematocrit was less than 25%. Rotational thromboelastometry (ROTEM) and standard laboratory tests were used to guide component blood products requirements.

Results:

Post-reperfusion, the COP, Cardiac Index (CI) and stroke volume (SV) increased significantly at all points of measurements; this was associated with a significant decrease in systemic vascular resistance (SVR) (P ;< .05). Immediately post-reperfusion, for 5 minutes, mean arterial blood pressure (ABP) dropped significantly (P < .05), and 14 out of the 25 patients required boluses of epinephrine (10 μg) to restore the mean ABP; 3 of the 14 patients required norepinephrine infusion till the end of surgery. Central venous pressure (CVP) and urine output (UOP) at all measures were maintained adequately with FTc-guided fluid replacement. Eight out of the 25 patients required no blood transfusion, and 4 of the 8 patients required no catecholamine support.

Conclusion:

TED as a sole monitor for COP was able to present significant and reliable changes in the cardiovascular status of the recipients during reperfusion, which could help to guide fluid- and drug-supportive therapy in this population of patients. This preliminary study needs to be applied on a larger scale.

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.