Intraoperative predictors of early tracheal extubation after living-donor liver transplantation

Relevant clinical factors for early extubation in living-donor liver transplantation: A single-center retrospective cohort study

BACKGROUND

Clinical guidelines for early extubation after liver transplantation remain lacking, with significant variations in the rates of early extubation across transplantation centers.

AIM

To identify clinical factors, including the use of epidural analgesia, associated with early extubation in living-donor liver transplantation (LDLT).

METHODS

The medical records of LDLT recipients were analyzed in this study, categorizing them based on extubation timing as delayed (leaving the operating room without extubation) or early (tracheal tube removed immediately after surgery). A multivariate binary logistic regression analysis was performed. Subgroup analysis was conducted, excluding patients contraindicated for epidural analgesia owing to significant coagulopathy.

RESULTS

Total of 159 patients, 93 (58.5%) underwent early extubation. Relevant clinical factors of early extubation were shorter anhepatic time [adjusted odds ratio (OR) = 0.439, 95% confidence interval (CI): 0.232-0.831; P = 0.011], absence of high-dose vasoactive drug use at the end of surgery (OR = 0.235, 95%CI: 0.106-0.519; P < 0.001), and the use of epidural analgesia (OR = 15.730, 95%CI: 1.919-128.919; P = 0.010). In a subgroup analysis of 67 patients, epidural analgesia remained a relevant clinical factor for early extubation (adjusted OR = 19.381, 95%CI: 2.15-174.433; P = 0.008).

CONCLUSION

Shorter anhepatic time, absence of high-dose vasoactive drug use at the end of surgery, and the use of epidural analgesia are relevant clinical factors of early extubation following LDLT.

Anesthesia and Critical Care for the Prediction and Prevention for Small-for-size Syndrome: Guidelines from the ILTS-iLDLT-LTSI Consensus Conference

BACKGROUND

During the perioperative period of living donor liver transplantation, anesthesiologists and intensivists may encounter patients in receipt of small grafts that puts them at risk of developing small for size syndrome (SFSS).

METHODS

A scientific committee (106 members from 21 countries) performed an extensive literature review on aspects of SFSS with proposed recommendations. Recommendations underwent a blinded review by an independent expert panel and discussion/voting on the recommendations occurred at a consensus conference organized by the International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplantation Society of India.

RESULTS

It was determined that centers with experience in living donor liver transplantation should utilize potential small for size grafts. Higher risk recipients with sarcopenia, cardiopulmonary, and renal dysfunction should receive small for size grafts with caution. In the intraoperative phase, a restrictive fluid strategy should be considered along with routine use of cardiac output monitoring, as well as use of pharmacologic portal flow modulation when appropriate. Postoperatively, these patients can be considered for enhanced recovery and should receive proactive monitoring for SFSS, nutrition optimization, infection prevention, and consideration for early renal replacement therapy for avoidance of graft congestion.

CONCLUSIONS

Our recommendations provide a framework for the optimal anesthetic and critical care management in the perioperative period for patients with grafts that put them at risk of developing SFSS. There is a significant limitation in the level of evidence for most recommendations. This statement aims to provide guidance for future research in the perioperative management of SFSS.

Predictive Score for Early Successful Tracheal Extubation After Liver Transplant: A Case-Control Study

OBJECTIVES

Prolonged tracheal intubation and mechanical ventilation after liver transplant increase postoperative complications. Hence, timely extubation should be considered; however, a standard clinical criteria set or scoring system to select patients has not been established for early extubation after livertransplant.We investigated the factors that affect early extubation to design a predictive scoring system for early extubation.

MATERIALS AND METHODS

This study is a case-control study of adult liver transplant patients. Preoperative, intraoperative, and postoperative clinical data were collected. Early extubation was defined as tracheal extubation immediately or up to 6 hours posttransplant. The variables were compared between the early extubation group and the delayed extubation (>6 hours) group.

RESULTS

Our study enrolled 237 patients; among them, 57 patients (24%) were in the early extubation group, and 180 (76%) were in the delayed extubation group. Multiple logistic regression analysis showed that postoperative base excess level at admission to the intensive care unit, number of units of packed red blood cells transfused during surgery, urine volume, and excess base level 6 hours after surgery were the main predictors of successful early extubation.

CONCLUSIONS

The initial base excess level at the entrance to the intensive care unit(postsurgery) and 6 hours after surgery, packed red blood cell volume transfused during surgery, and urine volume 6 hours after surgery are the main predictors for a successful early tracheal extubation.These factors are considered for the Shiraz Extubation Predictor formula.

Impact of Hyperoxia after Graft Reperfusion on Lactate Level and Outcomes in Adults Undergoing Orthotopic Liver Transplantation

BACKGROUND

Hyperoxia is common during liver transplantation (LT), without being supported by any guidelines. Recent studies have shown the potential deleterious effect of hyperoxia in similar models of ischemia-reperfusion. Hyperoxia after graft reperfusion during orthotopic LT could increase lactate levels and worsen patient outcomes.

METHODS

We conducted a retrospective and monocentric pilot study. All adult patients who underwent LT from 26 July 2013 to 26 December 2017 were considered for inclusion. Patients were classified into two groups according to oxygen levels before graft reperfusion: the hyperoxic group (PaO₂ > 200 mmHg) and the nonhyperoxic group (PaO₂ < 200 mmHg). The primary endpoint was arterial lactatemia 15 min after graft revascularization. Secondary endpoints included postoperative clinical outcomes and laboratory data.

RESULTS

A total of 222 liver transplant recipients were included. Arterial lactatemia after graft revascularization was significantly higher in the hyperoxic group (6.03 ± 4 mmol/L) than in the nonhyperoxic group (4.81 ± 2 mmol/L), p < 0.01. The postoperative hepatic cytolysis peak, duration of mechanical ventilation and duration of ileus were significantly increased in the hyperoxic group.

CONCLUSIONS

In the hyperoxic group, the arterial lactatemia, the hepatic cytolysis peak, the mechanical ventilation and the postoperative ileus were higher than in the nonhyperoxic group, suggesting that hyperoxia worsens short-term outcomes and could lead to increase ischemia-reperfusion injury after liver transplantation. A multicenter prospective study should be performed to confirm these results.

Outcomes following formation of a dedicated pediatric liver transplant anesthesia team

BACKGROUND

Given the complex nature of liver transplant surgery, adult centers typically use a dedicated liver transplant anesthesia team, which has improved patient outcomes.

AIMS

Our goal was to determine whether a dedicated pediatric liver transplant anesthesia team was associated with improved patient outcomes.

METHODS

This retrospective cohort study analyzed patients who underwent liver transplantation from April 2013 to September 2020 at St. Louis Children's Hospital. The general group (April 2013-December 2016) was compared with the liver group (January 2017-September 2020). Outcomes measured included cases per anesthesiologist, early extubation, ventilator days, fluid and blood administration, postoperative events, and intensive care unit and hospital length of stay (LOS).

RESULTS

Patients in both groups had similar demographics. The average number of cases/anesthesiologist/year was 2.9 times higher in the liver group (mean (SD) general 0.7 (0.5), liver 2.0 (0.6), and difference in mean [95% CI] 1.3 [0.8, 1.8]). The rate of extubation in the operating room was higher for patients in the liver group (general 56%, liver 80%, and difference in proportion [95% CI] 24.7 [7.0, 42.4]), while the number of ventilator days was lower (mean (SD) general 2.1 (4.4), liver 1.1 (3.6), and difference in proportion [95%CI] -0.9 [-2.6, 0.7]). Colloid administration was higher in the liver group (mean (SD) general 23.9 (14.5) ml/kg, liver 48.4 (37.7) ml/kg, and difference in mean [95% CI] 24.6 [12.7, 36.4]), while fresh frozen plasma administration was lower in the liver group (mean (SD) general 15.3 (23.9) ml/kg, liver 6.2 (14) ml/kg, and difference in mean [95% CI] -9.0 [-16.8, -1.3]). There were no significant differences between the groups in postoperative events including blood product transfusions, vasopressor use, and thromboses, or in the intensive care unit and hospital LOS.

CONCLUSIONS

The liver group was associated with increased early extubations, decreased ventilator days, and decreased fresh frozen plasma use.

Enhanced recovery in liver transplantation: A value-based approach to complex surgical care

BACKGROUND

Value-based healthcare focuses on improving outcomes relative to cost. We aimed to study the impact of an enhanced recovery pathway for liver transplant recipients on providing value.

METHODS

In total, 379 liver recipients were identified: pre-enhanced recovery pathway (2017, n = 57) and post-enhanced recovery pathway (2018-2020, n = 322). The enhanced recovery pathway bundle was defined through multidisciplinary efforts and included optimal fluid management, end-of-case extubation, multimodal analgesia, and a standardized care pathway. Pre- and post-enhanced recovery pathway patients were compared with regard to extubation rates, lengths of stay, complications, readmissions, survival, and costs.

RESULTS

Pre- and post-enhanced recovery pathway recipient model for end-stage liver disease score and balance of risk scores were similar, although post-enhanced recovery pathway recipients had a higher median donor risk index (1.55 vs 1.39, P = .003). End-of-case extubation rates were 78% post-enhanced recovery pathway (including 91% in 2020) versus 5% pre-enhanced recovery pathway, with post-enhanced recovery pathway patients having decreased median intraoperative transfusion requirements (1,500 vs 3,000 mL, P < .001). Post-enhanced recovery pathway recipients had shorter median intensive care unit (1.6 vs 2.3 days, P = .01) and hospital stays (5.4 vs 8.0 days, P < .001). Incidence of severe (Clavien-Dindo ≥3) complications during the index hospitalization were similar between pre-enhanced recovery pathway versus post-enhanced recovery pathway groups (33% vs 23%, P = .13), as were 30-day readmissions (26% vs 33%, P = .44) and 1-year survival (93.0% vs 94.5%, P = .58). The post-enhanced recovery pathway cohort demonstrated a significant reduction in median direct cost per case ($11,406; P < .001).

CONCLUSION

Implementation of an enhanced recovery pathway in liver transplantation is feasible, safe, and effective in delivering value, even in the setting of complex surgical care.

Predictors of success of immediate tracheal extubation in living donor liver transplantation recipients

Background

Early tracheal extubation of recipients following liver transplantation (LT) has been gradually replacing the standard postoperative prolonged mechanical ventilation, contributing to better patient and graft survival and reduced costs. There are no universally accepted predictors of the success of immediate extubation in LT recipients. We hypothesized several potential predictors of successful immediate tracheal extubation in living donor liver transplantation (LDLT) recipients.

Aim

Evaluation of the validity of the following hypothesized factors: model for end-stage liver disease (MELD) score, duration of surgery, number of intraoperatively transfused packed red blood cells (RBCs) units, and end of surgery (EOS) serum lactate, as predictors of success of immediate tracheal extubation in living donor liver transplantation (LDLT) recipients.

Methods

In this prospective clinical investigation, perioperative data of adult living donor liver transplantation (LDLT) recipients were recorded. “Immediate extubation” was defined as tracheal extubation immediately and up to 1 hour post-transplant in the operating room. Patients were divided into the extubated group who were successfully extubated with no need for reintubation, and the non-extubated group who failed to meet the criteria of extubation, or were re-intubated within 4 hours of extubation.

Results

We enrolled 64 patients candidates for LDLT; 50 patients (76.9%) in group 1 were extubated early after LDLT while 14 patients (23.07%) in group 2 were transferred to the intensive care unit intubated. After data analysis, we found that EOS serum lactate, duration of surgery and number of packed RBCs units transfused intraoperatively were good predictors of success of immediate extubation (p < 0.001). MELD scores did not show any significant impact on the results (p = 0.54). Other factors such as EOS urine output and blood gases indices were shown to have a significant effect on the decision of extubation (p = 0.03 and 0.006, respectively).

Conclusions

EOS serum lactate, duration of surgery and number of packed RBCs units transfused were potential predictors of post-transplant early extubation.

Predictive score for immediate extubation after liver transplantation

INTRODUCTION

Evidence suggests that immediate extubation after liver transplantation provides graft and economic benefits without compromising patient outcomes. This study tried to determine the incidence of immediate extubation, demonstrate related factors, and develop a predictive model from the significant factors.

METHODS

This retrospective descriptive study included 240 out of 271 liver transplantation patients in the hospital liver transplant registry between 2004 and 2016. Extubated and non-extubated groups were statistically compared.

RESULTS

The incidence of immediate extubation was 32.1%. It was associated with a MELD score ≤ 25 (adjusted OR, 5.17; 95% CI, 1.64-16.24; p = .005); packed red cells (PRC) transfusion ≤1600 ml (adjusted OR, 3.45; 95% CI, 1.82-6.53; p < .001); and no requirement for post-operative vasopressors (adjusted OR, 5.83; 95% CI, 2.30-14.77; p < .001). The immediate-extubation group had fewer complications and shorter hospital stays. A Siriraj Liver transplant Extubation Score (SLES) of 5 yielded the best prediction of safe immediate extubation.

CONCLUSIONS

An incidence of 32.1% was found for immediate extubation following liver transplantation. Associated factors were a MELD score ≤ 25, a lower amount of transfused blood, and no requirement for post-operative vasopressors. An SLES score of 5 predicted safe immediate extubation.

Effects of intraoperative hemodynamic management on postoperative acute kidney injury in liver transplantation: An observational cohort study

Background

Intraoperative restrictive fluid management strategies might improve postoperative outcomes in liver transplantation. Effects of vasopressors within any hemodynamic management strategy are unclear.

Methods

We conducted an observational cohort study on adult liver transplant recipients between July 2008 and December 2017. We measured the effect of vasopressors infused at admission in the intensive care unit (ICU) and total intraoperative fluid balance. Our primary outcome was 48-hour acute kidney injury (AKI) and our secondary outcomes were 7-day AKI, need for postoperative renal replacement therapy (RRT), time to extubation in the ICU, time to ICU discharge and survival up to 1 year. We fitted models adjusted for confounders using generalized estimating equations or survival models using robust standard errors. We reported results with 95% confidence intervals.

Results

We included 532 patients. Vasopressors use was not associated with 48-hour or 7-day AKI but modified the effects of fluid balance on RRT and mortality. A higher fluid balance was associated with a higher need for RRT (OR = 1.52 [1.15, 2.01], p<0.001 for interaction) and lower survival (HR = 1.71 [1.26, 2.34], p<0.01 for interaction) only among patients without vasopressors. In patients with vasopressors, higher doses of vasopressors were associated with a higher mortality (HR = 1.29 [1.13, 1.49] per 10 μg/min of norepinephrine).

Conclusion

The presence of any vasopressor at the end of surgery was not associated with AKI or RRT. The use of vasopressors might modify the harmful association between fluid balance and other postoperative outcomes. The liberal use of vasopressors to implement a restrictive fluid management strategy deserves further investigation.

Bias-corrected estimates of reduction of post-surgery length of stay and corresponding cost savings through the widespread national implementation of fast-tracking after liver transplantation: a quasi-experimental study

Background: Fast-tracking is an approach adopted by Mayo Clinic in Florida's (MCF) liver transplant (LT) program, which consists of early tracheal extubation and transfer of patients to surgical ward, eliminating a stay in the intensive care unit in select patients. Since adopting this approach in 2002, MCF has successfully fast-tracked 54.3% of patients undergoing LT. Objectives: This study evaluated the reduction in post-operative length of stay (LOS) that resulted from the fast-tracking protocol and assessed the potential cost saving in the case of nationwide implementation. Methods: A propensity score for fast-tracking was generated based on MCF liver transplant databases during 2011-2013. Various propensity score matching algorithms were used to form control groups from the United Network of Organ Sharing Standard Analysis and Research (STAR) file that had comparable demographic characteristics and health status to the treatment group identified in MCF. Multiple regression and matching estimators were employed for evaluation of the post-surgery LOS. The algorithm generated from the analysis was also applied to the STAR data to determine the proportion of patients in the US who could potentially be candidates for fast-tracking, and the potential savings. Results: The effect of the fast-tracking on the post-transplant LOS was estimated at approximately from 2.5 (p-value = 0.001) to 3.2 (p-value < 0.001) days based on various matching algorithms. The cost saving from a nationwide implementation of fast-tracking of liver transplant patients was estimated to be at least $78 million during the 2-year period. Conclusion: The fast-track program was found to be effective in reducing post-transplant LOS, although the reduction appeared to be less than previously reported. Nationwide implementation of fast-tracking could result in substantial cost savings without compromising the patient outcome.

Immediate versus conventional postoperative tracheal extubation for enhanced recovery after liver transplantation: IPTE versus CTE for enhanced recovery after liver transplantation

INTRODUCTION

To systematically compare immediate postoperative tracheal extubation (IPTE) with conventional tracheal extubation (CTE) and to determine whether IPTE can achieve an enhanced recovery for adult patients underwent liver transplantation (LT) without additional risks. We designed a systematic review and meta-analysis.

METHODS

The RCTs, cohorts, case-controls, or case series that explored outcomes of IPTE after LT for adults were involved in our study. The Newcastle-Ottawa scale was used to assess the risk of bias.

RESULTS

A total of 15 studies (n = 4144) were included, consisting of 10 studies (retrospective cohorts; n = 3387) for quantitative synthesis and 5 studies (1 prospective cohort, and 4 case series; n = 757) for qualitative synthesis. The pooled estimates suggested IPTE could reduce time to discharge from ICU stay (TDICU) (mean difference [MD] -2.12 days, 95% confidence interval [CI] -3.04 to -1.19 days), time to discharge from the hospital (TDH) (MD -6.43 days, 95% CI -9.53 to -3.33 days), re-intubation rate (RI) (odds ratio [OR] 0.29, 95% CI 0.22-0.39), morbidity rate (MR) (OR 0.15, 95% CI 0.08-0.30) and graft dysfunction rate (GD) (IPTE vs CTE: 0.3% vs 3.8%, P < .01), and had comparable ICU survival rate (ICUS) (OR 6.67 95% CI 1.34-33.35) when compared with CTE after LT.

CONCLUSIONS

IPTE can achieve an enhanced recovery for adult patients underwent LT without additional re-intubation, morbidity, and mortality risks. However, further work needs to be done to establish the extent definitively through carefully designed and conducted RCTs.