Etiologies, risk factors, and outcomes of bacterial pneumonia after living donor liver transplantation

Estimating risk of prolonged mechanical ventilation after liver transplantation in children: PROVE-ALT score

BACKGROUND

Children at high risk for prolonged mechanical ventilation (PMV) after liver transplantation (LT) need to be identified early to optimize pulmonary support, allocate resources, and improve surgical outcomes. We aimed to develop and validate a metric that can estimate risk for Prolonged Ventilation After LT (PROVE-ALT).

METHODS

We identified preoperative risk factors for PMV by univariable analysis in a retrospective cohort of pediatric LT recipients between 2011 and 2017 (n = 205; derivation cohort). We created the PROVE-ALT score by mapping multivariable logistic regression coefficients as integers, with cutoff values using the Youden Index. We validated the score by C-statistic in a retrospectively collected separate cohort of pediatric LT recipients between 2018 and 2021 (n = 133, validation cohort).

RESULTS

Among total 338 patients, 21% (n = 72) were infants; 49% (n = 167) had cirrhosis; 8% (n = 27) required continuous renal replacement therapy (CRRT); and 32% (n = 111) required management in hospital (MIH) before LT. Incidence of PMV post-LT was 20% (n = 69) and 3% (n = 12) required tracheostomy. Independent risk factors (OR [95% CI]) for PMV were cirrhosis (3.8 [1-14], p = .04); age <1-year (8.2 [2-30], p = .001); need for preoperative CRRT (6.3 [1.2-32], p = .02); and MIH before LT (12.4 [2.1-71], p = .004). PROVE-ALT score ≥8 [Range = 0-21] accurately predicted PMV in the validation cohort with 73% sensitivity and 80% specificity (AUC: 0.81; 95% CI: 0.71-0.91).

CONCLUSION

PROVE-ALT can predict PMV after pediatric LT with a high degree of sensitivity and specificity. Once externally validated in other centers, PROVE-ALT will empower clinicians to plan patient-specific ventilation strategies, provide parental anticipatory guidance, and optimize hospital resources.

Role of a Real-Time TDM-Based Expert Clinical Pharmacological Advice Program in Optimizing the Early Pharmacokinetic/Pharmacodynamic Target Attainment of Continuous Infusion Beta-Lactams among Orthotopic Liver Transplant Recipients with Documented or Suspected Gram-Negative Infections

(1) Objectives: To describe the attainment of optimal pharmacokinetic/pharmacodynamic (PK/PD) targets in orthotopic liver transplant (OLT) recipients treated with continuous infusion (CI) beta-lactams optimized using a real-time therapeutic drug monitoring (TDM)-guided expert clinical pharmacological advice (ECPA) program during the early post-surgical period. (2) Methods: OLT recipients admitted to the post-transplant intensive care unit over the period of July 2021-September 2023, receiving empirical or targeted therapy with CI meropenem, piperacillin-tazobactam, meropenem-vaborbactam, or ceftazidime-avibactam optimized using a real-time TDM-guided ECPA program, were retrospectively retrieved. Steady-state beta-lactam (BL) and/or beta-lactamase inhibitor (BLI) plasma concentrations (Css) were measured, and the Css/MIC ratio was selected as the best PK/PD target for beta-lactam efficacy. The PK/PD target of meropenem was defined as being optimal when attaining a fCss/MIC ratio > 4. The joint PK/PD target of the BL/BLI combinations (namely piperacillin-tazobactam, ceftazidime-avibactam, and meropenem-vaborbactam) was defined as being optimal when the fCss/MIC ratio > 4 of the BL and the fCss/target concentration (CT) ratio > 1 of tazobactam or avibactam, or the fAUC/CT ratio > 24 of vaborbactam were simultaneously attained. Multivariate logistic regression analysis was performed for testing potential variables that were associated with a failure in attaining early (i.e., at first TDM assessment) optimal PK/PD targets. (3) Results: Overall, 77 critically ill OLT recipients (median age, 57 years; male, 63.6%; median MELD score at transplantation, 17 points) receiving a total of 100 beta-lactam treatment courses, were included. Beta-lactam therapy was targeted in 43% of cases. Beta-lactam dosing adjustments were provided in 76 out of 100 first TDM assessments (76.0%; 69.0% decreases and 7.0% increases), and overall, in 134 out of 245 total ECPAs (54.7%). Optimal PK/PD target was attained early in 88% of treatment courses, and throughout beta-lactam therapy in 89% of cases. Augmented renal clearance (ARC; OR 7.64; 95%CI 1.32-44.13) and MIC values above the EUCAST clinical breakpoint (OR 91.55; 95%CI 7.12-1177.12) emerged as independent predictors of failure in attaining early optimal beta-lactam PK/PD targets. (4) Conclusion: A real-time TDM-guided ECPA program allowed for the attainment of optimal beta-lactam PK/PD targets in approximately 90% of critically ill OLT recipients treated with CI beta-lactams during the early post-transplant period. OLT recipients having ARC or being affected by pathogens with MIC values above the EUCAST clinical breakpoint were at high risk for failure in attaining early optimal beta-lactam PK/PD targets. Larger prospective studies are warranted for confirming our findings.

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.

Association between Hospital-Acquired Pneumonia and In-Hospital Mortality in Solid Organ Transplant Admissions: An Observational Analysis in Spain, 2004-2021

(1) Background: To analyze the association between hospital-acquired pneumonia (HAP) and in-hospital mortality (IHM) during hospital admission for solid organ transplant in Spain during 2004-2021. (2) Methods: We used national hospital discharge data to select all hospital admissions for kidney, liver, heart, and lung transplants. We stratified the data according to HAP status. To examine time trends, we grouped data into three consecutive 6-year periods (2004-2009; 2010-2015; and 2016-2021). We assessed in-hospital mortality (IHM) in logistic regression analyses and obtained odds ratios (ORs) with their 95% confidence intervals (CIs). (3) Results: We identified a total of 71,827 transplants (45,262, kidney; 18,127, liver; 4734, heart; and 4598, lung). Two thirds of the patients were men. Overall, the rate of HAP during admission was 2.6% and decreased from 3.0% during 2004-2009 to 2.4% during 2016-2021. The highest rate of HAP corresponded to lung transplant (9.4%), whereas we found the lowest rate for kidney transplant (1.1%). Rates of HAP for liver and heart transplants were 3.8% and 6.3%, respectively. IHM was significantly lower during 2016-2021 compared to 2004-2009 for all types of transplants (ORs (CIs) = 0.65 (0.53-0.79) for kidney; 0.73 (0.63-0.84) for liver; 0.72 (0.59-0.87) for heart; and 0.39 (0.31-0.47) for lung). HAP was associated with IHM for all types of transplants (ORs (CIs) = 4.47 (2.85-9.08) for kidney; 2.96 (2.34-3.75) for liver; 1.86 (1.34-2.57) for heart; and 2.97 (2.24-3.94) for lung). (4) Conclusions: Rates of HAP during admission for solid organ transplant differ depending on the type of transplant. Although IHM during admission for solid organ transplant has decreased over time in our country, HAP persists and is associated with a higher IHM after accounting for potential confounding variables.

Infection in Living Donor Liver Transplantation Leads to Increased Risk of Adverse Renal Outcomes

(1) Background: Little is known about the subsequent renal function change following incident infectious diseases in living-donor liver transplant (LT) recipients. (2) Methods: We studied patients who underwent living-donor LT from January 2003 to January 2019 to evaluate the association of incident hospitalization with major infections or pneumonia with adverse renal outcomes, including a sustained 40% reduction in estimated glomerular filtration rate (eGFR) and renal composite outcome (a 40% decline in eGFR, end-stage renal disease, or death.). Multivariable-adjusted time-dependent Cox models with infection as a time-varying exposure were used to estimate hazard ratio (HR) with 95% confidence interval (CI) for study outcomes. (3) Results: We identified 435 patients (mean age 54.6 ± 8.4 years and 76.3% men), of whom 102 had hospitalization with major infections during follow-up; the most common cause of infection was pneumonia (38.2%). In multiple Cox models, hospitalization with a major infection was associated with an increased risk of eGFR decline > 40% (HR, 3.32; 95% CI 2.13−5.16) and renal composite outcome (HR, 3.41; 95% CI 2.40−5.24). Likewise, pneumonia was also associated with an increased risk of eGFR decline > 40% (HR, 2.47; 95% CI 1.10−5.56) and renal composite outcome (HR, 4.37; 95% CI 2.39−8.02). (4) Conclusions: Our results illustrated the impact of a single infection episode on the future risk of adverse renal events in LT recipients. Whether preventive and prophylactic care bundles against infection and judicious modification of the immunosuppressive regimen benefit renal outcomes may deserve further study.

Pneumonia in solid organ transplantation: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These guidelines from the AST Infectious Diseases Community of Practice review the diagnosis and management of pneumonia in the post-transplant period. Clinical presentations and differential diagnosis for pneumonia in the solid organ transplant recipient are reviewed. A two-tier approach is proposed based on the net state of immunosuppression and the severity of presentation. With a lower risk of opportunistic, hospital-acquired, or exposure-specific pathogens and a non-severe presentation, empirical therapy may be initiated under close clinical observation. In all other patients, or those not responding to the initial therapy, a more aggressive diagnostic approach including sampling of tissue for microbiological and pathological testing is warranted. Given the broad range of potential pathogens, a microbiological diagnosis is often key for optimal care. Given the limited literature comparatively evaluating diagnostic approaches to pneumonia in the solid organ transplant recipient, much of the proposed diagnostic algorithm reflects clinical experience rather than evidence-based data. It should serve as a template which may be modified according to local needs. The same holds true for the suggested empiric therapies, which need to be adapted to the local resistance patterns. Further study is needed to comparatively evaluate diagnostic and empiric treatment strategies in SOT recipients.

Influence of gut microbiota and intestinal barrier on enterogenic infection after liver transplantation

Liver transplantation is currently a standard therapy for patients with end-stage liver diseases and hepatocellular carcinoma. Given that liver transplantation has undergone a thriving development in these decades, the survival rates after liver transplantation have markedly improved as a result of the critical advancement in surgical techniques, immunosuppressive therapies, and post-operative care. However, infection remains a fatal complication after liver transplantation surgery. In particular, enterogenic infection represents a major complication in liver transplant recipients. This article gives an overview of infection cases after liver transplantation and focuses on the discussion of enterogenic infection in terms of its pathophysiology, risk factor, outcome, and treatment.

Albumin-Bilirubin Score for Predicting Post-Transplant Complications Following Adult-to-Adult Living Donor Liver Transplantation

Background

Albumin-Bilirubin (ALBI) grade has been evaluated as an objective method to assess liver function and predict postoperative complications, particularly after hepatectomy in patients with hepatocellular carcinoma (HCC). However, ALBI grade was rarely used in evaluation in living donor liver transplantation (LDLT).

Material/Methods

Between March 2005 and November 2015, 272 consecutive patients undergoing right-lobe LDLT were enrolled in this study. According to the ALBI score used to evaluate recipients preoperatively, those patients were divided into 3 grades (I, II, and III). Demographic findings and the post-operative complication rates were collected and compared among groups.

Results

The proportions of massive blood cell transfusions were different among those 3 grades (p<0.05). The patients in grade III had a higher risk of bacterial pneumonia and early allograft dysfunction (EAD) compared to grade I (p=0.029 and p=0.038, respectively) and grade II (p=0.006 and p=0.007, respectively). The area under the receiver operating characteristic curve of ALBI, Child-Pugh, and MELD for predicting 30-day mortality were 0.702 (95% CI: 0.644–0.756), 0.669 (95% CI: 0.580–0.697, p=0.510, versus ALBI grade), and 0.540 (95% CI: 0.580–0.697, p=0.144, versus ALBI grade), respectively.

Conclusions

ALBI grade was a good index for predicting post-operative complications and had a predictive ability similar to those of the Child-Pugh classification and MELD score.

Early Bacterial Pneumonia After Hepatic Transplantation: Epidemiologic Profile

BACKGROUND

Postoperative pulmonary complications are major cause of morbidity and mortality in patients receiving liver transplantation (LT), particularly bacterial pneumonia occurring within the first 100 days after transplantation. Our aim in this study was to determine the incidence, microorganisms involved, associated factors, and morbidity of bacterial pneumonia presenting in the first 100 days posttransplant.

METHODS

We performed a cohort study in which patients receiving liver transplantation were included prospectively in our national database (Database of Infections in Transplantation of Solid Organs). The study period was from July 14, 2009 to July 24, 2015.

RESULTS

One hundred six patients were transplanted during the 6-year period. We documented 9 bacterial pneumonia cases with an incidence of 8.5 per 100 patients; 2 patients had hospital-acquired pneumonia (HAP) and 7 had ventilator-associated pneumonia (VAP). In 4 of the 9 bacterial pneumonia cases, patients presented with bacteremia. Eleven microorganisms were isolated these 9 patients. Microbiologic diagnosis methods included 5 cases of alveolar bronchoalveolar lavage (BAL), 1 case of BAL and pleural fluid puncture, 1 case of pleural fluid puncture, and 1 case through sputum study. Of the 11 isolated organisms, 9 corresponded to Gram-negative bacilli (GNB): Klebsiella spp, n = 3; Acinetobacter baumannii, n = 4; Morganella morganii, n = 1; and Pseudomonas aeruginosa, n = 1. Regarding the resistance profile, 7 presented with a multiresistance profile (MDR) and extreme resistance (XDR). Univariate analysis identified the Model for End-Stage Liver Disease (MELD) pretransplant score as a factor associated with developing pneumonia (P < .001, 95% confidence interval [CI] 2.872-10.167), and early extubation, before 8 hours posttransplant, as a protective factor (P = .008; relative risk [RR] 0.124; 95% CI 0 .041-0.377). Hospital stay was longer in patients with pneumonia compared to those without pneumonia (P < .0001, 95% CI 17.79-43.11 days). There was also an increased risk of death in patients with pneumonia (RR 17.963; 95% CI 5106-63,195).

CONCLUSIONS

Early bacterial pneumonia after hepatic transplantation is associated with higher morbidity and mortality. At our center, 4 of 9 patients had bacteremia. GNB cases with MDR and XDR profiles are predominant. Early extubation is a protective factor.

Intensive Care of Pulmonary Complications Following Liver Transplantation

Chronic liver disease has been associated with pulmonary dysfunction both before and after liver transplantation. Post-liver transplantation pulmonary complications can affect both morbidity and mortality often necessitating intensive care during the immediate postoperative period. The major pulmonary complications include pneumonia, pleural effusions, pulmonary edema, and atelectasis. Poor clinical outcomes have been known to be associated with age, severity of liver dysfunction, and preexisting lung disease as well as perioperative events related to fluid balance, particularly transfusion and fluid volumes. Delineating each and every one of these pulmonary complications and their associated risk factors becomes paramount in guiding specific therapeutic strategies.

Effects of infection on post-transplant outcomes: living versus deceased donor liver transplants

Introduction

Post-transplant infections have been studied widely but data on comparisons of deceased donor liver transplants (DDLT) and living donor liver transplants (LDLT), type and timings of infections, and their relations to outcomes are not explored.

Material and methods

We analysed data from 612 participants of the Adult-to-Adult Living Donor Liver Transplantation Study (A2ALL), a retrospective data set of LDLT and DDLT. We compared the type and timing of the first post-transplant infection in relation to transplant outcomes between the two groups.

Results

Out of 611 patients, 24.5% experienced the first post-transplant infection, the majority of which were bacterial (35.3%), followed by fungal (11%) and viral infections (4.2%). There was no significant difference in the rate, type or timing of infection between LDLT and DDLT. Patients with late (> 1 year) first infection were 1.8 times more likely to die (95% CI: 1.12-2.98, p = 0.015) and 9 times more likely to have graft failures (95% CI: 3.26-24.8, p < 0.001). DDLT recipients who experienced bacterial infection had a significantly lower survival rate compared to LDLT recipients (p < 0.001).

Conclusions

Late infection is associated with lower survival in both DDLT and LDLT. Bacterial infection might be more detrimental for DDLT than LDLT. Late infection should be managed aggressively to improve outcomes.

Early-Onset Pneumonia After Liver Transplant: Microbial Causes, Risk Factors, and Outcomes, Mansoura University, Egypt, Experience

OBJECTIVES

Pneumonia has a negative effect on the outcome of liver transplant. Our aim was to analyze early-onset pneumonia that developed within the first month after transplant.

MATERIALS AND METHODS

This prospective single-center study included 56 adult living-donor liver transplant recipients; those who developed early-onset pneumonia based on clinical and radiologic criteria were investigated as to causative pathogens and then followed up and compared with other recipients without pneumonia to illustrate risk factors, outcomes, and related mortality of posttransplant pneumonia.

RESULTS

Twelve patients (21.4%) developed early-onset pneumonia with mortality rate of 75% (9 of 12). Sixteen pathogens were isolated; extended spectrum beta-lactamase producing Enterobacteriaceae were the most common (31.2%) followed by carbapenem-producing Enterobacteriaceae and methicillin-resistant Staphylococcus aureus (18.8%). Fungi were isolated in 3 cases that were also coinfected with bacteria. Diabetes mellitus (P = .042), liberal postoperative fluid therapy (P = .028), prolonged posttransplant intensive care unit stay (P = .01), atelectasis grade ≥ 2 (P ≤ .001), and calcineurin inhibitor-induced neurotoxicity (P = .04) were risk factors for early posttransplant pneumonia.

CONCLUSIONS

Pneumonia is the leading cause of early mortality after liver transplant. The emergence of multidrug-resistant bacteria is major issue associated with a high rate of treatment failure.

Pre-Transplantation Immune Cell Distribution and Early Post-Transplant Fungal Infection Are the Main Risk Factors of Liver Transplantation Recipients in Lower Model of End-Stage Liver Disease

BACKGROUND

The prognosis of patients after liver transplantation (LTx) with high Model of End-Stage Liver Disease (MELD) score (>30) is predicted, but patients with lower MELD scores (<30) have no conclusive studies of pre- and post-transplant risk factors that influence the long-term outcome.

METHODS

This retrospective study reviewed 268 recipients with MELD score <30, from 2008 to 2013 in our institution, for evaluation of pre-transplant risk factors including patients' clinical background data, pre-transplant lymphocyte subpopulation, and early post-transplant infection complication as predictors for long-term survival after LTx.

RESULTS

The post-transplant patients' survival estimates were 90.7%, 85.1%, and 83.6% at 1, 3, and 5 years, respectively. In multivariate analysis, age >55years, presence of ascites, cluster of differentiation (CD)3 < 93.2 (count/μL), CD4/CD8 <2.4, fungal infection, and more than one site of fungal colonization significantly influenced survival (P = .0003, P = .002, P = .04, P = .004, P < .0001, and P > .0001, respectively). We also noticed that these five factors accumulatively influence the long-term survival rate; this means that in the presence of any two risk factors, the 5-year survival can still be 88.4%, whereas in the presence of any three risk factors, the survival rate dropped to only 57.1%.

CONCLUSIONS

Older patients in the presence of pre-transplant low immune cell number and ascites in association with post-transplant fungal infection are the independent risk factors in MELD scores <30 LTx groups for long-term survival. Patients in these groups with any of the three factors had inferior long-term survival results.

Impact of Pre-Transplant Bacterial Infections on Post-Operative Outcomes in Patients after Liver Transplantation

BACKGROUND

In contrast to studies evaluating the negative effect of bacterial infections on clinical outcomes after liver transplantation, there is little evidence with regard to pre-transplant bacterial infections. We aimed to investigate the impact of pre-transplant bacterial infections on post-transplant outcomes in patients after liver transplantation.

PATIENTS AND METHODS

We retrospectively analyzed clinical data from 33 consecutive patients who underwent primary liver transplantations. Patients were divided into two groups based on the occurrence of a bacterial infection within the 30 days before transplantation.

RESULTS

Of the 33 patients, 23 patients did not have pre-transplant bacterial infections, while 10 patients did have pre-transplant bacterial infections. Pre-transplant bacterial infections were urinary tract infections (n = 4), spontaneous bacterial peritonitis (n = 3), and one each of pneumonia, bacteremia, and cellulitis. There were no differences in clinical characteristics between the two groups. Post-operative clinical outcomes, including post-operative bacterial infection, intensive-care unit re-admission, 30-day re-hospitalization, and 90-day mortality rate were not significantly different between the two groups. The two-year overall survival rate was 76.7% in patients with pre-transplant infections and 80.0% in those without pre-transplant infections.

CONCLUSIONS

Patients with pre-transplant bacterial infections did not have inferior clinical outcomes, compared with those without pre-transplant bacterial infections.

Utility of percutaneous dilatational tracheostomy in the inmediate postoperative period of liver transplant

OBJECTIVE

To determinate the safety of percutaneous dilatational tracheostomy (PDT) on hepatic allograft recipients.

PATIENTS AND METHODS

We reviewed the records of patients who underwent liver transplantation between October 2007 and April 2013, followed by PDT. In this time period, 25 liver recipients underwent PDT in our intensive care unit. We recorded severity index scores such as APACHE II and SAPS II, number of days since intubation, ratios of PaO2/FiO2 (arterial oxygen pressure to fraction of inspired oxygen), coagulation study findings, complications, and procedure-related mortality rates. We compared these records with the general ICU population and literature reports.

RESULTS

The median age was 58 (IC range 47-65) and 64% were men. The median time since intubation to PDT was 11 days (IC range 6.5-15.5) and from transplant to PDT 12 days. The median ratio of PaO2/FiO2 was 212 (IC range 177-259). The median platelet count was 89 (IC range 37-149), significantly lower than the general ICU population (272 (IC range 186-381) P=.001). Complications were infrequent and included clinically remarkable major bleeding 8% (vs. 0,3% in general ICU population; P=.005), peristomal infection (4%) and ventilator-associated pneumonia 16% (vs. 2,8% in general ICU population; P=.007). There were no deaths associated with the procedures.

CONCLUSION

PDT was tolerated well in recipients of liver allografts and had a relatively low risk of major complications and a low procedure-related mortality rate.

Bacterial infection after liver transplantation

Infectious complications are major causes of morbidity and mortality after liver transplantation, despite recent advances in the transplant field. Bacteria, fungi, viruses and parasites can cause infection before and after transplantation. Among them, bacterial infections are predominant during the first two months post-transplantation and affect patient and graft survival. They might cause surgical site infections, including deep intra-abdominal infections, bacteremia, pneumonia, catheter-related infections and urinary tract infections. The risk factors for bacterial infections differ between the periods after transplant, and between centers. Recently, the emergence of multi-drug resistant bacteria is great concern in liver transplant (LT) patients. The instructive data about effects of infections with extended-spectrum beta lactamase producing bacteria, carbapenem-resistant gram-negative bacteria, and glycopeptide-resistant gram-positive bacteria were reported on a center-by-center basis. To prevent post-transplant bacterial infections, proper strategies need to be established based upon center-specific data and evidence from well-controlled studies. This article reviewed the recent epidemiological data, risk factors for each type of infections and important clinical issues in bacterial infection after LT.

Early respiratory complications after liver transplantation

The poor clinical conditions associated with end-stage cirrhosis, pre-existing pulmonary abnormalities, and high comorbidity rates in patients with high Model for End-Stage Liver Disease scores are all well-recognized factors that increase the risk of pulmonary complications after orthotopic liver transplantation (OLT) surgery. Many intraoperative and postoperative events, such as fluid overload, massive transfusion of blood products, hemodynamic instability, unexpected coagulation abnormalities, renal dysfunction, and serious adverse effects of reperfusion syndrome, are other factors that predispose an individual to postoperative respiratory disorders. Despite advances in surgical techniques and anesthesiological management, the lung may still suffer throughout the perioperative period from various types of injury and ventilatory impairment, with different clinical outcomes. Pulmonary complications after OLT can be classified as infectious or non-infectious. Pleural effusion, atelectasis, pulmonary edema, respiratory distress syndrome, and pneumonia may contribute considerably to early morbidity and mortality in liver transplant patients. It is of paramount importance to accurately identify lung disorders because infectious pulmonary complications warrant speedy and aggressive treatment to prevent diffuse lung injury and the risk of evolution into multisystem organ failure. This review discusses the most common perioperative factors that predispose an individual to postoperative pulmonary complications and these complications’ early clinical manifestations after OLT and influence on patient outcome.

Risk factors for early bacterial infections in liver transplantation

OBJECTIVE

Our aim was to determine perioperative risk factors for early bacterial infection after liver transplantation.

METHODS

Retrospectively examining medical records using Centers for Disease Control and Prevention (CDC) definitions to identify nosocomial infections, we analyzed data on 367 adult patients.

RESULTS

The incidence of infection was 37.3% (n = 137): namely, surgical site (n = 74; 20.2%) [corrected], blood stream (n = 64; 17.4%), pulmonary (n = 49; 13.4%), urinary system (n = 26; 7.1%). Significant risk factors within the first 30 days were as follows: deceased donor, Model for End-Stage Liver Disease (MELD) >20, albumin level <2.8 g/dL, intraoperative erythrocyte transfusion >6 U, intraoperative fresh frozen plasma >12 U, bilioenteric anastomosis, postoperative intensive care unit stay >6 days, and postoperative length of stay >21 days. Significant risk factors detected within the first 90 days were as follows: MELD >20, preoperative length of stay >7 days, reoperation, postoperative length of intensive care unit stay >6 days, and postoperative length of stay >21 days. Variability was observed in risk factors according to localization of infection. As a result, except for MELD, type of donor, and biliary anastomosis, the others are preventable factors for early bacterial infection. In addition, the same risk factors showed variability according to the site of infection.

Impacts of pretransplant infections on clinical outcomes of patients with acute-on-chronic liver failure who received living-donor liver transplantation

Background

Liver transplantation is the only therapeutic modality for patients with acute-on chronic liver failure (ACLF). These patients are at high risk for bacterial infections while awaiting transplantation. The aim of this study was to elucidate whether an adequately treated bacterial infection influences the outcomes after transplantation in this patient population.

Methodology/Principal Findings

54 recipients (median age, 49.5 years [range, 22–60]) of adult-to-adult living donor liver transplant (LDLT) for ACLF were categorized as those with pretransplant infection (Group 1, n = 34) or without pretransplant infection (Group 2, n = 20) for retrospective analyses. With the exception of a higher male-female ratio (P = 0.046) and longer length of pretransplant hospital stay (P = 0.026) in Group 1, similar demographic, laboratory and clinical features were found in both groups. Patients in Group 1 (totally 42 pretransplant infection episodes) were adequately treated with effective antibiotic(s) before receiving LDLT. All included patients were followed up until one year after transplantation or death. Sixty-one posttransplant infection episodes were found in an overall of 44 ACLF patients (27 in Group 1 vs. 15 in Group 2; P = 0.352). Frequently encountered posttransplant infections were intraabdominal infection, pneumonia, bloodstream infection and urinary tract infection. Two patients died in each group (P = 0.622). No significant difference was found in the length of posttransplant ICU stay, and in one-year survival, graft rejection, and posttransplant infection rate between both groups. The longer overall hospital stay (mean day, 89.0 vs. 65.5, P = 0.024) found in Group 1 resulted from a longer pretransplant hospital stay receiving treatment for pretransplant infection(s) and/or awaiting transplantation.

Conclusions

These data suggested that an adequately treated pretransplant infection do not pose a significant risk for clinical outcomes including posttransplant fatality in recipients in adult-to-adult LDLT for ACLF.

Current status of research on enterogenic infection following liver transplantation

Since the introduction of the Milan criteria in 1996, liver transplantation has become a standard therapy for end-stage liver diseases and hepatocellular carcinoma. In recent years, liver transplantation has developed greatly. Survival rates after liver transplantation have markedly improved as a result of improved operative techniques, use of immunosuppressants, etc. But infection, especially enterogenic infection, is still the most disturbing complication in patients undergoing liver transplantation. This article gives an overview of infection after liver transplantation and focuses on the discussion of enterogenic infection in terms of its pathophysiology, risk factors, outcome, diagnosis and treatment.