Early Bacterial Pneumonia After Hepatic Transplantation: Epidemiologic Profile

A nomogram for predicting early bacterial infection after liver transplantation: a retrospective study

Background

Bacterial infection is a common complication of liver transplantation and is associated with high mortality rates. However, multifactor-based early-prediction tools are currently lacking. Therefore, this study investigated the risk factors of early bacterial infections after liver transplantation and used them to establish a nomogram.

Methods

We retrospectively collected the clinical data of 232 patients who underwent liver transplantation. We excluded 15 patients aged less than 18 years, 7 patients with infection before transplantation, and 3 patients with incomplete laboratory test results based on the sample exclusion criteria, and finally included 207 liver transplant patients. The patients were divided into the bacterial infection group (75 cases) and non-infected group (132 cases) according to whether bacterial infection had occurred within 30 days after surgery. The associated risk factors were determined using stepwise regression, and a nomogram was established based on the results of the multifactorial analysis. The predictive performance of the model was compared by assessing the area under the receiver operating characteristic curve (AUC-ROC), decision curve analysis (DCA), and the calibration curve, which was validated using cross-validation and repeated sampling.

Result

Preoperative systemic immune inflammation index (SII) (OR = 1.003, p = 0.001), duration of surgery (OR = 1.008, p = 0.005), duration of postoperative ventilator use (OR = 1.013, p = 0.025), neutrophil to lymphocyte ratio (NLR) (OR = 1.017, p = 0.024), ICU stay time (OR = 1.125, p = 0.015) were independent risk factors for early bacterial infection after liver transplantation. The nomogram was constructed based on the above factors, achieving an AUC of 0.863 (95%CI: 0.808, 0.918), which showed that the mean absolute error between the predicted risk and the actual risk of the model was 0.044. The decision curve analysis showed that it was located above both extreme curves in a range of more than the 14% threshold, which indicated that there was a good clinical benefit in this range. Internal validation using 10-fold cross validation and bootstrap replicate sampling yielded areas under the corrected ROC curves of 0.842 and 0.854, respectively. These results indicate that the developed model exhibits good predictive performance and a moderate error in training and validation.

Conclusion

The nomogram constructed in this study showed good differentiation, calibration, and clinical applicability. It can effectively identify the high-risk group for bacterial infection in the early postoperative period after liver transplantation, while simultaneously helping the transplant team dynamically monitor the key indicators and optimize perioperative management.

Burden and Management of Multi-Drug Resistant Organism Infections in Solid Organ Transplant Recipients Across the World: A Narrative Review

Solid organ transplant (SOT) recipients are particularly susceptible to infections caused by multidrug-resistant organisms (MDRO) and are often the first to be affected by an emerging resistant pathogen. Unfortunately, their prevalence and impact on morbidity and mortality according to the type of graft is not systematically reported from high-as well as from low and middle-income countries (HIC and LMIC). Thus, epidemiology on MDRO in SOT recipients could be subjected to reporting bias. In addition, screening practices and diagnostic resources may vary between countries, as well as the availability of new drugs. In this review, we aimed to depict the burden of main Gram-negative MDRO in SOT patients across HIC and LMIC and to provide an overview of current diagnostic and therapeutic resources.

Epidemiology and Prevention of Early Infections by Multi-Drug-Resistant Organisms in Adults Undergoing Liver Transplant: A Narrative Review

Invasive bacterial infections are a leading cause of morbidity and mortality after liver transplant (LT), especially during the first months after LT, and infections due to multi-drug-resistant organisms (MDRO) are increasing in this setting. Most of the infections in patients in intensive care unit arise from the endogenous microflora and, for this reason, pre-LT MDRO rectal colonization is a risk factor for developing MDRO infections in the post-LT. Moreover, the transplanted liver may carry an increased risk of MDRO infections due to organ transportation and preservation, to donor intensive care unit stay and previous antibiotic exposure. To date, little evidence is available about how MDRO pre-LT colonization in donors and recipients should address LT preventive and antibiotic prophylactic strategies, in order to reduce MDRO infections in the post-LT period. The present review provided an extensive overview of the recent literature on these topics, with the aim to offer a comprehensive insight about the epidemiology of MDRO colonization and infections in adult LT recipients, donor-derived MDRO infections, possible surveillance, and prophylactic strategies to reduce post-LT MDRO infections.

The role of early extubation on short-term outcomes after liver transplantation - A systematic review, meta-analysis and expert recommendations

BACKGROUND

Early extubation in liver transplantation (LT) and its potential benefits such as reduction in pulmonary complications and enhanced postoperative recovery have been described. The extent of the effect of early extubation on short-term outcomes after LT across the published literature is to the best of our knowledge unknown.

OBJECTIVES

The objective of this systematic review and meta-analysis was to determine whether early extubation improves immediate and short-term outcomes after LT and to provide expert recommendations.

DATA SOURCES

Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central.

METHODS

A systematic review and meta-analysis on short-term outcomes after early extubation in LT was performed (CRD42021241402), following PRISMA guidelines and quality of evidence (QOE) and recommendations grading using the GRADE approach, derived from an international experts panel. Endpoints were reintubation rates, pulmonary and other complications/organ dysfunction, intensive care unit (ICU) and hospital length of stay (LOS).

RESULTS

Of 831 screened articles, 20 observational studies with a total of 3573 patients addressing early extubation protocols were included, of which 12 studies compared results after early versus deferred extubation. Reintubation and pulmonary complication rates were lower in the early versus deferred extubation groups (OR 0.29, CI 0.22-0.39; OR 0.17, CI 0.09-0.33, respectively). ICU and hospital LOS were shorter in eight out of eight and seven out of eight comparative studies, respectively.

CONCLUSIONS

Early extubation after LT is associated with improved short-term outcomes after LT and should be performed in the majority of patients (QOE; Moderate to low | Grade of Recommendation; Strong). Randomized controlled trials using standardized definitions of early extubation and short-term outcomes are needed to demonstrate causality, validate and allow comparability of the results.

Ventriculoperitoneal shunt management in children undergoing liver transplantation

There is a lack of data to guide neurosurgeons on the management of ventriculoperitoneal shunts (VPS) in patients undergoing abdominal transplant operations. We present the cases of two pediatric patients with VPS undergoing liver transplantation who were successfully managed with externalization of the VPS at time of transplantation, with subsequent re-internalization once cleared by the transplant surgery team. We present this as an effective management strategy in patients undergoing liver transplantation.

Diversity in the swimming motility and flagellar regulon structure of uropathogenic Morganella morganii strains

In current times, the opportunistic pathogen Morganella morganii is increasingly becoming a cause of urinary tract infections. The condition has been further complicated by the multiple drug resistance of most isolates. Swimming motility plays an important role in the development of urinary tract infections, allowing bacteria to colonize the upper urinary tract. We determined the differences between the growth, swimming motility, and biofilm formation of two M. morganii strains MM 1 and MM 190 isolated from the urine of patients who had community-acquired urinary tract infections. MM 190 showed a lower growth rate but better-formed biofilms in comparison to MM 1. In addition, MM 190 possessed autoaggregation abilities. It was found that a high temperature (37 °C) inhibits the flagellation of strains and makes MM 190 less motile. At the same time, the MM 1 strain maintained its rate of motility at this temperature. We demonstrated that urea at a concentration of 1.5% suppresses the growth and swimming motility of both strains. Genome analysis showed that MM 1 has a 17.7-kb-long insertion in flagellar regulon between fliE and glycosyltransferase genes, which was not identified in corresponding loci of MM 190 and 9 other M. morganii strains with whole genomes. Both strains carry two genes encoding flagellin, which may indicate flagellar antigen phase variation. However, the fliC2 genes have only 91% identity to each other and exhibit some variability in the regulatory region. We assume that all these differences influence the swimming motility of the strains.

Challenges in the Diagnosis and Management of Bacterial Lung Infections in Solid Organ Recipients: A Narrative Review

Respiratory infections pose a significant threat to the success of solid organ transplantation, and the diagnosis and management of these infections are challenging. The current narrative review addressed some of these challenges, based on evidence from the literature published in the last 20 years. Specifically, we focused our attention on (i) the obstacles to an etiologic diagnosis of respiratory infections among solid organ transplant recipients, (ii) the management of bacterial respiratory infections in an era characterized by increased antimicrobial resistance, and (iii) the development of antimicrobial stewardship programs dedicated to solid organ transplant recipients.

Health Care-Associated Infection in Solid Organ Transplant Recipients

BACKGROUND

Health care-associated infection (HAI) represent a global health problem with an increase in hospital stays, deaths, and monetary costs. Recipients of solid organ transplants are a population at risk. The objectives of the study were to characterize the incidence of HAI in renal and hepatic transplant recipients as well as to compare them with the population without transplants in intensive care units (ICU).

METHODS

The data on the incidence of HAI, localization, microorganisms, and demographics were taken from the patients admitted between the years 2013 to 2018 (n = 4307) from the registration of the Project for the Reduction of Nosocomial Infection in Intensive Care Units. The variables were compared with those of renal transplant (n = 96) and liver transplants (n = 68) recipients.

RESULTS

Renal transplant recipients showed 26% incidence of HAI. The most frequent were surgical site infection (SSI), urinary tract infection, and primary bacteremia; the most frequent microorganism was Staphylococcus spp, mortality 3.8%. Liver transplant recipients showed 41% incidence of HAI. The most frequent were tracheobronchitis associated with mechanical ventilation, SSI, and primary bacteremia; the most frequent microorganism was Staphylococcus spp, mortality 37%. The population without transplants in the ICU showed 17% incidence of HAI. The most frequent were respiratory infections associated with mechanical ventilation, primary bacteremia, and SSI; the most frequent microorganism was Acinetobacter spp, mortality 21%.

CONCLUSIONS

HAI in recipients of solid organ transplants (renal and hepatic) have a higher incidence than in a population without transplants. The location and causal microorganisms have particularities that must be taken into account for the development of prevention protocols.

Critical Care Management of Living Donor Liver Transplants

This article represents a review of the postoperative management of donors and recipients after living donor liver transplant, including monitoring, liberation from mechanical ventilation, nutritional support, and pain control. Vascular complications, such as biliary and sepsis, and bleeding are also discussed. Finally, commonly used immunosuppression and antimicrobial prophylaxes are reviewed.