Selective decontamination of the digestive tract: rationale behind evidence-based use in liver transplantation

Risk factors of early bacterial infection and analysis of bacterial composition, distribution and drug susceptibility after cadaveric liver transplantation

BACKGROUND

This study provided a theoretical basis for the clinical diagnosis and treatment of bacterial infection after liver transplantation through analyzing the pathogenic distribution, drug sensitivity and risk factors of bacterial infection after liver transplantation.

METHODS

We collected clinical data from 207 recipients undergoing liver transplantation of graft from donation after citizens' death donors in the Third Xiangya Hospital of Central South University from January 2019 to December 2021 and analyzed the composition and distribution of bacterial pathogens, drug resistance and risk factors of infection.

RESULTS

A total of 90 bacterial infections occurred in 55 recipients within two months after liver transplantation, and the incidence of bacterial infection was 26.6% (55/207). The gram-negative bacteria (46/90, 51.1%) were more prevalent than gram-positive bacteria (44/90, 48.9%). Common sites of infection were the abdominal/biliary tract (26/90, 28.9%), lung (22/90, 22.4%) and urinary tract (22/90, 22.4%). Fourteen cases (6.8%) died after liver transplantation. Klebsiella pneumoniae (17/90, 18.9%) was the most frequent gram-negative bacteria causing infection in liver transplant recipients and 58.7%, 50%, 80.4% and 89.1% of gram-negative bacteria were sensitive to amikacin, minocycline, tigecycline and polymyxin B, respectively. The most common gram-positive bacteria was Enterococcus faecium (30/90, 33.3%) and 97.7%, 100%, 86.4%, 100% and 100% of gram-positive bacteria were sensitive to vancomycin, teicoplanin, daptomycin, tigecycline and linezolid, respectively. Univariate analysis revealed that bacterial infection was associated with female, age (≥ 50 years old), preoperative albumin (≤ 30 g/L), operation duration (≥ 400 min), intraoperative blood loss (≥ 3000 ml) and postoperative ventilator support. Binary Logistic regression analysis showed that female (OR = 3.149, 95% CI: 1.418-6.993, P = 0.005), operation duration (≥ 400 min) (OR = 2.393, 95% CI: 1.202-4.765, P = 0.013) and intraoperative blood loss (≥ 3000 ml) (OR = 2.052, 95% CI: 1.007-4.183, P = 0.048) were independent risk factors for bacterial infection after liver transplantation.

CONCLUSION

The incidence of early bacterial infection after liver transplantation was high, and the infection sites were mainly abdominal/biliary tract, respiratory tract and urinary tract. The most common pathogenic bacterium was gram-negative bacterium. Our study also identified several independent risk factors for bacterial infection after liver transplantation, including female gender, operation duration of 400 min or more, and intraoperative blood loss of 3000 ml or more. By addressing these risk factors, such as implementing strategies to optimize surgical procedures and minimize blood loss, healthcare professionals can work towards reducing the incidence of bacterial infections following liver transplantation.

Bacterial infections in the early period after liver transplantation in adults: A prospective single-center cohort study

Liver transplantation (LT) is a potentially curative treatment for terminal stage hepatic diseases. Bacterial infections are the main causes of mortality and morbidity in the early period after LT. Identifying the risk factors could help in minimizing their development. We prospectively investigated the incidence, characteristics, and risk factors of bacterial infections among the recipients during hospitalization after LT and assigned a predictive score. All 389 consecutive adults who underwent LT at the main referral hospital of LT in Iran during 1 year were enrolled prospectively in a cohort study. Infection group consisted of 143 recipients (36.8%). Urinary tract and surgical site infections were the most frequent ones. Gram-negative bacteria were more prevalent than Gram-positive ones. Independent risk factors were female sex (relative risks = 2.13), age ≤ 43.5 years (3.70), hospital stay ≥ 9.5 days (5.22), abdominal reoperation (3.03), vancomycin-resistant Enterococci colonization (5.52), hospitalization 3 months prior to LT (3.25), mechanical ventilation ≥48 hr (4.93), and renal replacement therapies (13.40). We developed a risk score for the prediction of bacterial infections with an area under the receiver operating characteristic curve of 0.85 (95% CI, 0.81-0.89) with sensitivity of 88% and specificity of 64%. In the infection group, mortality was higher than in controls (18.9% vs. 2.0%) with longer hospitalization (16 vs. 10 days; P < 0.001). We detected a high rate of bacterial infections leading to longer hospital stay and higher mortality rate. The formulated risk score can help predict bacterial infections; however, it requires clinical validation in further studies.

Selective intestinal decontamination for the prevention of early bacterial infections after liver transplantation

Bacterial infection in the first month after liver transplantation is a frequent complication that poses a serious risk for liver transplant recipients as contributes substantially to increased length of hospitalization and hospital costs being a leading cause of death in this period. Most of these infections are caused by gram-negative bacilli, although gram-positive infections, especially Enterococcus sp. constitute an emerging infectious problem. This high rate of early postoperative infections after liver transplant has generated interest in exploring various prophylactic approaches to surmount this problem. One of these approaches is selective intestinal decontamination (SID). SID is a prophylactic strategy that consists of the administration of antimicrobials with limited anaerobicidal activity in order to reduce the burden of aerobic gram-negative bacteria and/or yeast in the intestinal tract and so prevent infections caused by these organisms. The majority of studies carried out to date have found SID to be effective in the reduction of gram-negative infection, but the effect on overall infection is limited due to a higher number of infection episodes by pathogenic enterococci and coagulase-negative staphylococci. However, difficulties in general extrapolation of the favorable results obtained in specific studies together with the potential risk of selection of multirresistant microorganisms has conditioned controversy about the routinely application of these strategies in liver transplant recipients.

Bacterial biliary tract infections in liver transplant recipients

PURPOSE OF REVIEW

The purpose of this study is to provide an overview of bacterial biliary tract infections in liver transplant recipients with a focus on pathogenesis and conservative treatment strategies.

RECENT FINDINGS

The development of interventional endoscopic and radiologic interventions has improved the outcome of conservative treatments for bile tract strictures and bilomas. However, recent data show an important rise of infections with multidrug-resistant (MDR) pathogens in liver transplant recipients.

SUMMARY

Both recurrent cholangitis and infected bilomas are bacterial biliary tract infections in liver transplant recipients responsible for significant morbidity and graft loss, which require a multidisciplinary approach. Risk factors for biliary tract strictures and bilomas formation have recently been identified. With the improved outcome of a conservative management including prolonged and/or recurrent antibiotic treatments, the risk of selecting resistant pathogens is increased. There is an urgent need to develop new strategies to reduce the risk of secondary infections by MDR isolates in liver transplant recipients.

A comparative study of the use of selective digestive decontamination prophylaxis in living-donor liver transplant recipients

INTRODUCTION

Bacterial infections are major causes of early morbidity and mortality after liver transplantation. Selective digestive decontamination (SDD) can be used pre-operatively for living-donor liver transplant (LD-LT), but its role in this setting remains controversial.

METHODS

To evaluate this strategy, we retrospectively analyzed a cohort of consecutive LD-LTs performed in our center from March 2007 to February 2011 and compared the incidence and nature of early infectious complications, length of intensive care unit stay and hospitalization, antibiotic use, and emergence of resistant bacteria in patients with or without SDD prophylaxis.

RESULTS

Of 148 LD-LTs in the study period, 111 received SDD prophylaxis while 37 did not. In a multivariate model, the independent factors associated with an increased risk of early post-transplant infections were length of postoperative mechanical ventilation (for every additional day odds ratio [OR] = 2.37, 95% confidence interval [CI] 1.4-4.0; P = 0.002), and choledochojejunostomy (OR = 4.5, 95% CI 1.95-10.5; P < 0.001). Use of SDD did not affect the rate or distribution of infectious complications, duration of hospitalization, antibiotic use, or acquisition of resistant bacteria (OR = 3.52, 95% CI 0.43-15.17; P = 0.376).

CONCLUSION

In conclusion, the use of SDD prophylaxis in LD-LT was not beneficial and should be avoided, as it offers no advantage and could potentiate the emergence of multidrug-resistant organisms.

Management of infections pre- and post-liver transplantation: report of an AISF consensus conference

The burden of infectious diseases both before and after liver transplantation is clearly attributable to the dysfunction of defensive mechanisms of the host, both as a result of cirrhosis, as well as the use of immunosuppressive agents. The present document represents the recommendations of an expert panel commended by the Italian Association for the Study of the Liver (AISF), on the prevention and management of infectious complications excluding hepatitis B, D, C, and HIV in the setting of liver transplantation. Due to a decreased response to vaccinations in cirrhosis as well as within the first six months after transplantation, the best timing for immunization is likely before transplant and early in the course of disease. Before transplantation, a vaccination panel including inactivated as well as live attenuated vaccines is recommended, while oral polio vaccine, Calmette-Guerin's bacillus, and Smallpox are contraindicated, whereas after transplantation, live attenuated vaccines are contraindicated. Before transplant, screening protocols should be divided into different levels according to the likelihood of infection, in order to reduce costs for the National Health Service. Recommended preoperative and postoperative prophylaxis varies according to the pathologic agent to which it is directed (bacterial vs. viral vs. fungal). Timing after transplantation greatly determines the most likely agent involved in post-transplant infections, and specific high-risk categories of patients have been identified that warrant closer surveillance. Clearly, specifically targeted treatment protocols are needed upon diagnosis of infections in both the pre- as well as the post-transplant scenarios, not without considering local microbiology and resistance patterns.

Selective intestinal decontamination with fluoroquinolones for the prevention of early bacterial infections after liver transplantation

The role of selective intestinal decontamination with fluoroquinolones (FQ-SID) in the prevention of early bacterial infections (EBIs) in liver transplant recipients (LTRs) is unknown. We used the online database of the Spanish Network of Infection in Transplantation/Spanish Network for Research in Infectious Diseases, which prospectively analyzed 1010 LTRs from 12 Spanish hospitals from September 2003 to February 2005. We compared the incidence and etiology of EBIs (30 days after transplantation) in 415 LTRs from 4 centers that used FQ-SID (>7 days) and in 595 LTRs from 8 hospitals that did not use FQ-SID. A multivariate logistic regression analysis (including an adjustment for the transplant center factor) was performed to evaluate the potential protective factor of FQ-SID in the development of EBIs. We reported 266 EBI episodes in 252 LTRs (incidence = 24.9%). There were no differences in the incidence of EBIs between patients in the FQ-SID group and patients not in the FQ-SID group [109/415 (26.3%) versus 143/595 (24%), P = 0.9]. Although LTRs who received FQ-SID had a lower incidence of infections due to enteric bacteria (2.7% versus 6.5%, P = 0.007) and a higher incidence of infections due to nonfermenting gram-negative bacilli (6.6% versus 2.6%, P = 0.004), these findings could not be confirmed after an adjustment by the center factor in the multivariate models. We found no significant differences in the incidence of enterococcal infections (3.4% with FQ-SID versus 3.9% without FQ-SID, P = 0.5). Multivariate analysis did not confirm any protective effect of FQ-SID against the development of EBIs by enteric bacteria. In conclusion, FQ-SID does not reduce the incidence of EBIs in LTRs and could be withheld from this group of patients.

Update of early respiratory failure in the lung transplant recipient

PURPOSE OF REVIEW

Respiratory failure remains the most common complication in the perioperative period after lung transplantation. Consequently it is important to develop an approach to diagnosis and the treatment of respiratory failure in this population. This review highlights the advances made in the understanding and treatment of lung transplant patients in the early postoperative phase. Owing to its relative importance, advances in the understanding and treatment of ischaemia-reperfusion injury are highlighted.

RECENT FINDINGS

The causes of respiratory failure and the complications seen after transplantation are time dependent, with ischaemia-reperfusion, infection, technical problems and acute rejection being the most common in the early perioperative phase, and obliterative bronchiolitis, rejection, and infections secondary to bacteria, fungi, and viruses becoming more prevalent after 3 months. The advances in lung preservation and postoperative care may be overshadowed by an increase in the complexity of the recipients and the use of more marginal organs. An improved mechanistic understanding of ischaemia-reperfusion injury has translated into potential therapeutic targets. The development of prospective clinical trials, however, is hampered by a relatively small sample of patients and a significant degree of heterogeneity in the lung transplant population.

SUMMARY

Many advances have been made in the understanding of ischaemia-reperfusion injury. Owing to the acute and long-term implications of this complication, interventions that reduce the risk of developing ischaemia-reperfusion need to be evaluated in prospective clinical trials.