Pulmonary complications following adult liver transplantation

Thrombocytopenia Predicts Poor Prognosis of Liver Transplantation

BACKGROUND/AIM

Platelets not only participate in physiological hemostasis but also play a major role in liver ischemia-reperfusion injury, liver damage, tissue repair, and liver regeneration. A decrease in platelet count can lead to spontaneous bleeding, infection, and other complications that can seriously impact patient prognosis. Thrombocytopenia has been associated with increased complications after partial hepatectomy, although the effects of thrombocytopenia on patient outcomes remain unclear. Therefore, this study aimed to examine the impact of thrombocytopenia on short- and long-term prognosis following liver transplantation (LT).

METHODS

This was a retrospective analysis comprising 234 adult liver transplant recipients and conducted from January 2019 to June 2022. Preoperative and postoperative daily platelet counts were recorded up to the 30th postoperative day (POD). We defined people with platelet counts <70 × 109/L as the low platelet group, and people with platelet counts >70 × 109/L as the high platelet group. Multivariate analysis was carried out to determine whether low perioperative platelet count was a risk factor for postoperative complications, graft failure, and patient survival.

RESULTS

Of the 234 patients analyzed in this study, approximately half (n = 112, 47.9%) developed persistent thrombocytopenia after LT. The most substantial decrease in platelet levels occurred on POD7. The cumulative survival rates at 1, 2, and 3 years in the high platelet group were higher than those in the low platelet group, 94%, 87%, and 85%, respectively, while those of the low platelet group were 84%, 78%, and 70% (P = .0014). In addition, the high platelet group had a lower incidence of biliary complications compared with the low platelet group (8% vs 19%, P = .020). At the same time, the high platelet group had a lower incidence of posttransplant lung infection (55% vs 75%, P = .040).

CONCLUSIONS

Thrombocytopenia is a common complication of LT. It indicates the severity of the postoperative course and is closely associated with patient survival. In particular, patients who undergo orthotopic liver transplantation (OLT) and have a platelet count <70 × 109/L on the POD7 have significant negative prognostic implications and should be further investigated.

Pleural Effusion and Malnutrition Are Associated With Worse Early Outcomes After Liver Transplant

INTRODUCTION

Pulmonary complications after liver transplantation (LT) have previously been associated with longer hospital stays and ventilator time, and higher mortality. This study reports the outcomes for a specific pulmonary complication, pleural effusion, in LT recipients.

METHODS

Records from a single transplant center were analyzed retrospectively for all adult LT patients. Patients with documented pleural effusion by radiographic imaging within 30 days pre- or post-transplant were considered as cases. Outcomes included length of hospital stay, discharge disposition, hospital readmission, discharge with home oxygen, and 1-year survival.

RESULTS

During the 4-year study period, 512 LTs were performed, with 107 patients (21%) developing a peri-transplant pleural effusion. In total, 49 patients (10%) had a pre-transplant effusion, 91 (18%) had a post-transplant effusion, and 32 (6%) had both. Characteristics associated with the presence of any pleural effusion included an increasing model for end-stage liver disease score, re-transplantation, diagnosis of alcoholic liver disease, low protein levels, and sarcopenia. Effusion patients had longer hospital stays (17 vs 9 days, P < .001) and higher likelihood of discharge to a care facility (48% vs 21%, P < .001). Ninety-day readmission occurred in 69% of effusion patients (vs 44%, P < .001). One-year patient survival with any effusion was 86% (vs 94%, P < .01).

CONCLUSIONS

Overall, 21% of recipients developed a clinically significant peri-transplant pleural effusion. Pleural effusion was associated with worse outcomes for all clinical measures. Risk factors for the development of pleural effusion included higher MELD score (>20), re-transplantation, alcoholic liver disease, and poor nutrition status, including poor muscle mass.

Implications of Pleural Fluid Composition in Persistent Pleural Effusion following Orthotopic Liver Transplant

Persistent pleural effusions (PPEf) represent a known complication of orthotopic liver transplant (OLT). However, their clinical relevance is not well described. We evaluated the clinical, biochemical, and cellular characteristics of post-OLT PPEf and assessed their relationship with longitudinal outcomes. We performed a retrospective cohort study of OLT recipients between 2006 and 2015. Included patients had post-OLT PPEf, defined by effusion persisting >30 days after OLT and available pleural fluid analysis. PPEf were classified as transudates or exudates (Exud^Light) by Light's criteria. Exudates were subclassified as those with elevated lactate dehydrogenase (Exud^LDH) or elevated protein (Exud^Prot). Cellular composition was classified as neutrophil- or lymphocyte-predominant. Of 1602 OLT patients, 124 (7.7%) had PPEf, of which 90.2% were Exud^Light. Compared to all OLT recipients, PPEf patients had lower two-year survival (HR 1.63; p = 0.002). Among PPEf patients, one-year mortality was associated with pleural fluid RBC count (p = 0.03). While Exud^Light and Exud^Prot showed no association with outcomes, Exud^LDH were associated with increased ventilator dependence (p = 0.03) and postoperative length of stay (p = 0.03). Neutrophil-predominant effusions were associated with increased postoperative ventilator dependence (p = 0.03), vasopressor dependence (p = 0.02), and surgical pleural intervention (p = 0.02). In summary, post-OLT PPEf were associated with increased mortality. Ninety percent of these effusions were exudates by Light's criteria. Defining exudates using LDH only and incorporating cellular analysis, including neutrophils and RBCs, was useful in predicting morbidity.

Surgical chest complications after liver transplantation

Liver transplantation is a major abdominal operation and the intimate anatomic relation of the liver with the right hemidiaphragm predisposes the patient to various manifestations in the chest cavity. Furthermore, chronic liver disease affects pulmonary function before and after liver transplantation resulting in a considerable percentage of patients presenting with morbidity related to chest complications. This review aims to identify the potential chest complications of surgical interest during or after liver transplantation. Complications of surgical interest are defined as those conditions that necessitate an invasive procedure (such as thoracocentesis or a chest tube placement) in the chest or a surgical intervention performed by a thoracic surgeon. These complications will be classified as perioperative and postoperative; the latter will be categorized as early and late. Although thoracocentesis or a chest tube placement is usually sufficient when invasive measures are deemed necessary, in some patients, thoracic surgical interventions are warranted. A high index of suspicion is needed to recognize and treat these conditions promptly. A close collaboration between abdominal surgeons, intensive care unit physicians and thoracic surgeons is of paramount importance.

Effect of cardiac output - guided hemodynamic management on acute lung injury in pediatric living donor liver transplantation

BACKGROUND

Acute lung injury (ALI) after liver transplantation (LT) may lead to acute respiratory distress syndrome, which is associated with adverse postoperative outcomes, such as prolonged hospital stay, high morbidity, and mortality. Therefore, it is vital to maintain hemodynamic stability and optimize fluid management. However, few studies have reported cardiac output-guided (CO-G) management in pediatric LT.

AIM

To investigate the effect of CO-G hemodynamic management on early postoperative ALI and hemodynamic stability during pediatric living donor LT.

METHODS

A total of 130 pediatric patients scheduled for elective living donor LT were enrolled as study participants and were assigned to the control group (65 cases) and CO-G group (65 cases). In the CO-G group, CO was considered the target for hemodynamic management. In the control group, hemodynamic management was based on usual perioperative care guided by central venous pressure, continuous invasive arterial pressure, urinary volume, etc. The primary outcome was early postoperative ALI. Secondary outcomes included other early postoperative pulmonary complications, readmission to the intense care unit (ICU) for pulmonary complications, ICU stay, hospital stay, and in-hospital mortality.

RESULTS

The incidence of early postoperative ALI was 27.7% in the CO-G group, which was significantly lower than that in the control group (44.6%) (P < 0.05). During the surgery, the incidence of postreperfusion syndrome was lower in the CO-G group (P < 0.05). The level of intraoperative positive fluid transfusions was lower and the rate of dobutamine use before portal vein opening was higher, while the usage and dosage of epinephrine during portal vein opening and vasoactive inotropic score after portal vein opening were lower in the CO-G group (P < 0.05). Compared to the control group, serum inflammatory factors (interleukin-6 and tumor necrosis factor-α), cardiac troponin I, and N-terminal pro-brain natriuretic peptide were lower in the CO-G group after the operation (P < 0.05).

CONCLUSION

CO-G hemodynamic management in pediatric living-donor LT decreases the incidence of early postoperative ALI due to hemodynamic stability through optimized fluid management and appropriate administration of vasopressors and inotropes.

Transfusion-Related Acute Lung Injury During Liver Transplantation: A Scoping Review

Liver transplantation is associated with significant blood loss, often requiring massive blood product transfusion. Transfusion-related acute lung injury (TRALI) is a devastating cause of transfusion-related deaths. While reports have investigated the general incidence of TRALI, the incidence of TRALI specifically following transfusion during liver transplant remains unclear. This scoping review summarizes existing literature regarding TRALI during the liver transplantation perioperative period. Databases were searched for all articles and abstracts reporting on TRALI after liver transplantation. Data collected included number of patients studied, patient characteristics, incidences of TRALI, TRALI characteristics, and patient outcomes. The primary outcome investigated was the incidence of TRALI in the setting of liver transplantation. Thirteen full-text citations were included in this review. The incidence of TRALI post-liver transplant was 0.68% (65 of 9,554). Based on reported transfusion data, patients diagnosed with TRALI received an average of 10.92 ± 10.81 units of packed red blood cells (pRBC), 20.05 ± 15.72 units of fresh frozen plasma, and 5.75 ± 10.00 units of platelets. Common interventions following TRALI diagnosis included mechanical ventilation with positive end-expiratory pressure, inhaled high-flow oxygen, inhaled pulmonary vasodilator, and pharmacologic treatment using pressors or inotropes, corticosteroids, or diuretics. Based on reported mortality data, 26.67% of patients (12 of 45) diagnosed with TRALI died during the postoperative period. This scoping review underscores the importance of better understanding the incidence and presentation of TRALI after liver transplant surgery. The clinical implications of these results warrant the development of identification and management strategies for liver transplant patients at increased risk for developing TRALI.

The Edge of Unknown: Postoperative Critical Care in Liver Transplantation

Perioperative care of patients undergoing liver transplantation (LT) is very complex. Metabolic derangements, hypothermia, coagulopathy and thromboses, severe infections, and graft dysfunction can affect outcomes. In this manuscript, we discuss several perioperative problems that can be encountered in LT recipients. The authors present the most up-to-date information regarding predicting and treating hemodynamic instability, coagulation monitoring and management, postoperative ventilation strategies and early extubation, management of infections, and ESLD-related pulmonary complications. In addition, early post-transplant allograft dysfunction will be discussed.

Postoperative Trapped Lung After Orthotopic Liver Transplantation is a Predictor of Increased Mortality

Pleural effusions are a common complication of orthotopic liver transplantation (OLT), and chronic post-OLT pleural effusions have been associated with worse outcomes. Furthermore, “trapped lung” (TL), defined as a restrictive fibrous visceral pleural peel preventing lung re-expansion, may have prognostic significance. We performed a retrospective analysis of adult OLT recipients over a 9-year period at UCLA Medical Center. Post-OLT patients with persistent pleural effusions, defined by the presence of pleural fluid requiring drainage one to 12 months after OLT, were included for analysis. Outcomes for patients with and without TL were compared using univariate and multivariate analysis. Of the 1722 patients who underwent OLT, 117 (7%) patients met our criteria for persistent postoperative pleural effusion, and the incidence of TL was 21.4% (25/117). Compared to patients without TL, those with TL required more surgical pleural procedures (OR 59.8, 95%CI 19.7–181.4, p < 0.001), spent more days in the hospital (IRR 1.56, 95%CI 1.09–2.23, p = 0.015), and had a higher risk of mortality (HR 2.47, 95%CI 1.59–3.82, p < 0.001) following transplant. In sum, we found that post-OLT TL was associated with higher morbidity, mortality, and healthcare utilization. Future prospective investigation is warranted to further clarify the risk factors for developing postoperative pleural effusions and TL.

Epidemiology and Prognostic Significance of Rapid Response System Activation in Patients Undergoing Liver Transplantation

Patients undergoing liver transplantation have a high risk of perioperative clinical deterioration. The Rapid Response System is an intensive care unit-based approach for the early recognition and management of hospitalized patients identified as high-risk for clinical deterioration by a medical emergency team (MET). The etiology and prognostic significance of clinical deterioration events is poorly understood in liver transplant patients. We conducted a cohort study of 381 consecutive adult liver transplant recipients from a prospectively collected transplant database (2011–2017). Medical records identified patients who received MET activation pre- and post-transplantation. MET activation was recorded in 131 (34%) patients, with 266 MET activations in total. The commonest triggers for MET activation were tachypnea and hypotension pre-transplantation, and tachycardia post-transplantation. In multivariable analysis, female sex, increasing Model for End-Stage Liver Disease score and hepatorenal syndrome were independently associated with MET activation. The unplanned intensive care unit admission rate following MET activation was 24.1%. Inpatient mortality was 4.2% and did not differ by MET activation status; however, patients requiring MET activation had significantly longer intensive care unit and hospital length of stay and were more likely to require inpatient rehabilitation. In conclusion, liver transplant patients with perioperative complications requiring MET activation represent a high-risk group with increased morbidity and length of stay.

Risk factor for lung infection in recipients after liver transplantation: A meta-analysis

Lung infection (LI) often occurs in patients with liver transplantation (LT). This meta-analysis was conducted to determine the risk factors associated with LI after LT. We retrieved relevant research published as of February 2020 from eight electronic databases. The studies were reviewed against the inclusion and exclusion criteria. The Z test was used to determine the combined odds ratio (OR) or the standardized mean difference (SMD) of the risk factors. We used the OR and its corresponding 95% confidence interval (CI) or the SMD and its corresponding 95% CI to identify significant differences in risk factors. A total of nine studies were included, comprising a total of 1624 recipients. Six risk factors associated with LI were identified after LT: Model for end-stage liver disease score (MELD score) (SMD = 0.40), Child-Pugh class C (OR = 3.00), intensive care unit (ICU) hospital stay (SMD = 1.35), mechanical ventilation (SMD = 1.03), bilirubin (SMD = 0.39), and atelectasis (OR = 7.28). Although certain risk factors have been identified as important factors for LI after LT, which may provide a basis for clinical prevention, a well-designed prospective study should be conducted to validate the findings of this study.

Predictors of Mortality During Initial Liver Transplant Hospitalization and Investigation of Causes of Death

BACKGROUND Liver transplant (LT) remains a life-saving procedure with a high mortality rate. The present study investigated the causes of death and sought to identify predictive factors of mortality during the initial LT hospitalization. MATERIAL AND METHODS We retrieved data on first-time adult recipients who underwent LT between November 2017 and October 2019 receiving grafts from donation after citizen's death. The risk factors for mortality during the initial LT hospitalization were confirmed by univariate analysis. We also analyzed the causes of death. RESULTS We enrolled 103 recipients, including 86 males and 17 females, with a mean age of 47.7 years. Thirty-eight (36.9%) recipients were labeled as non-cholestatic cirrhosis-related indications. Approximately 8% of all recipients had diabetes prior to LT. Induction therapy was used in 11 (10.7%) recipients, along with maintenance therapy. The median model for end-stage liver disease score at LT was 32.4 (21.4-38.4). The in-hospital mortality rate of LT recipients was 6.8% (7/103), and infections were responsible for most of the deaths (6/7). The 1 remaining death resulted from primary graft failure. Univariate analysis showed recipients with postoperative pneumonia (p2 mg/dL, and alanine transaminase on day 1 after LT >1800 µmol/L (all P<0.001) were much more likely to die. CONCLUSIONS In-hospital mortality of LT recipients was high, due in large part to infections. Acute hepatic necrosis, prolonged post-transplant ICU stays, certain types of postoperative infections, and postoperative liver and kidney dysfunction were potential risk factors for in-hospital mortality of LT recipients.

Cost Utilization and the Use of Pulmonary Function Tests in Preoperative Liver Transplant Patients

BACKGROUND

Pulmonary function tests (PFTs) are currently recommended for liver transplant candidates. We hypothesized that PFTs may not provide added clinical value to the evaluation of liver transplant patients.

METHODS

We conducted a retrospective cohort study of adult cadaveric liver transplants from 2012 to 2018. Abnormal PFTs were defined as restrictive disease of diffusing capacity of the lungs for carbon monoxide (DLCO) <80% or obstructive disease of ratio of forced expiratory volume in the first 1 second to the first vital capacity of the lungs (FEV1/FVC) <70%.

RESULTS

We analyzed data on 415 liver transplant patients (358 abnormal PFT results and 57 normal results). The liver transplant patients with abnormal PFTs had no difference in number of intensive care unit (ICU) days (P = .68), length of stay (P = .24), or intubation days (P = .33). There were no differences in pulmonary complications including pleural effusion (P = .30), hemo/pneumothorax (P = .74), pneumonia (P = .66), acute respiratory distress syndrome (P = .57), or pulmonary edema (P = .73). The significant finding between groups was a higher rate of reintubation in liver transplant patients with normal PFTs (P = .02). There was no difference in graft survival (P = .53) or patient survival (P = .42).

DISCUSSION

Abnormal PFTs, found in 86% of liver transplant patients, did not correlate with complications, graft failure, or mortality. PFTs contribute to the high cost of liver transplants but do not help predict which patients are at risk of postoperative complications.

Pleural Effusions Following Liver Transplantation: A Single-Center Experience

INTRODUCTION

This was a single-center retrospective study to evaluate incidence, prognosis, and risk factors in patients with postoperative pleural effusions, a common pulmonary complication following liver transplantation.

METHODS

A retrospective review was performed on 374 liver transplantation cases through a database within the timeframe of January 1, 2009 through December 31, 2015. Demographics, pulmonary and cardiac function testing, laboratory studies, intraoperative transfusion/infusion volumes, postoperative management, and outcomes were analyzed.

RESULTS

In the immediate postoperative period, 189 (50.5%) developed pleural effusions following liver transplantation of which 145 (76.7%) resolved within 3 months. Those who developed pleural effusions demonstrated a lower fibrinogen (149.6 ± 66.3 mg/dL vs 178.4 ± 87.3 mg/dL; P = .009), total protein (5.8 ± 1.0 mg/dL vs 6.1 ± 1.2 mg/dL; P = .04), and hemoglobin (9.8 ± 1.8 mg/dL vs 10.3 ± 1.9 mg/dL; P = .004). There was not a statistically significant difference in 1-year all-cause mortality and in-hospital mortality between liver transplant recipients with and without pleural effusions. Liver transplant recipients who developed pleural effusions had a longer hospital length of stay (16.4 ± 10.9 days vs 14.0 ± 16.5 days; P = .1), but the differences were not statistically significant. However, there was a significant difference in tracheostomy rates (11.6% vs 5.4%; P = .03) in recipients who developed pleural effusions compared to recipients who did not.

CONCLUSIONS

In summary, pleural effusions are common after liver transplantation and are associated with increased morbidity. Pre- and intraoperative risk factors can offer both predictive and prognostic value for post-transplantation pleural effusions. Further prospective studies will be needed to further evaluate the relevance of these findings to limit instances of postoperative pleural effusions.

Perioperative Pleural Drainage in Liver Transplantation: A Retrospective Analysis from a High-Volume Liver Transplant Center

BACKGROUND Pleural effusions represent a common complication after liver transplantation (LT) and chest drain (CD) placement is frequently necessary. MATERIAL AND METHODS In this retrospective cohort study, adult LT recipients between 2009 and 2016 were analyzed for pleural effusion formation and its treatment within the first 10 postoperative days. The aim of the study was to compare different settings of CD placement with regard to intervention-related complications. RESULTS Overall, 597 patients met the inclusion criteria, of which 361 patients (60.5%) received at least 1 CD within the study period. Patients with a MELD >25 were more frequently affected (75.7% versus 56.0%, P<0.001). Typically, CDs were placed in the intensive care unit (ICU) (66.8%) or in the operating room (14.1% during LT, 11.5% in the context of reoperations). In total, 97.0% of the patients received a right-sided CD, presumably caused by local irritations. Approximately one-third (35.4%) of ICU-patients required pre-interventional optimization of coagulation. Of the 361 patients receiving a CD, 15 patients (4.2%) suffered a post-interventional hemorrhage and 6 patients (1.4%) had a pneumothorax requiring further treatment. Less complications were observed when the CD was performed in the operating room compared to the ICU: 1 out 127 patients (0.8%) versus 20 out of 332 patients (6.0%); P=0.016. CONCLUSIONS CD placement occurring in the operating room was associated with fewer complications in contrast to placement occurring in the ICU. Planned CD placement in the course of surgery might be favorable in high-risk patients.

Association of Perioperative Variables and the Acute Respiratory Distress Syndrome in Liver Transplant Recipients

Background

The assessment of perioperative risk factors for the development of acute respiratory distress syndrome (ARDS) has been described in various surgical populations. However, there are only limited data among patients undergoing liver transplantation (LT), particularly regarding the influence of intraoperative ventilation parameters. We sought to identify the perioperative risk factors associated with the development of ARDS in LT recipients.

Methods

This is a single-center, retrospective cohort study of adult patients who underwent LT at a tertiary academic medical center between January 1, 2006, and January 31, 2016. Postoperative ARDS was identified using the Berlin definition. Multivariable logistic regression analysis was used to identify perioperative risk factors for ARDS.

Results

Of 817 eligible patients who underwent an LT during the study period, 20 (2.45%) developed postoperative ARDS. In the preoperative model, ongoing dialysis (odds ratio, 6.41; P < 0.01) was identified as an independent risk factor of ARDS post-LT. A higher mean peak inspiratory pressure per increase of 1 cm H₂O (odds ratio, 1.31; P < 0.01) was the only independent risk factor in the intraoperative model. Patients who developed ARDS postoperatively had significantly greater intensive care unit and hospital stay compared to non-ARDS patients (P < 0.001). There were no significant differences in the 30-day (P = 0.16) and 1-year (P = 0.51) mortality between the groups.

Conclusions

Dialysis at the time of transplant and elevated intraoperative mean peak inspiratory pressure were associated with the development of ARDS. ARDS post LT was associated with increased intensive care unit and hospital length of stay, but not increased mortality.

Invasive mould infections in solid organ transplant patients: modifiers and indicators of disease and treatment response

PURPOSE

Invasive mould infections, in particular invasive aspergillosis (IA), are comparatively frequent complications of immunosuppression in patients undergoing solid organ transplantation (SOT). Guidelines provide recommendations as to the procedures to be carried out to diagnose and treat IA, but only limited advice for SOT recipients.

METHODS

Literature review and expert consensus summarising the existing evidence related to prophylaxis, diagnosis, treatment and assessment of response to IA and infections by Mucorales in SOT patients RESULTS: Response to therapy should be assessed early and at regular intervals. No indications of improvement should lead to a prompt change of the antifungal treatment, to account for possible infections by Mucorales or other moulds such as Scedosporium. Imaging techniques, especially CT scan and possibly angiography carried out at regular intervals during early and long-term follow-up and coupled with a careful clinical diagnostic workout, should be evaluated as diagnostic tools and outcome predictors, and standardised to improve therapy monitoring. The role of biomarkers such as the galactomannan test and PCR, as well as selected inflammation parameters, has not yet been definitively assessed in the SOT population and needs to be studied further. The therapeutic workup should consider a reduction of immunosuppressive therapy.

CONCLUSIONS

The role of immunosuppression and immune tolerance mechanisms in the response to invasive fungal infection treatment is an important factor in the SOT population and should not be underestimated. The choice of the antifungal should consider not only their toxicity but also their effects on the immune system, two features that are intertwined.

Neutrophil Elastase Inhibitors Suppress Oxidative Stress in Lung during Liver Transplantation

Background

Neutrophil infiltration plays a critical role in the pathogenesis of acute lung injury following liver transplantation (LT). Neutrophil elastase is released from neutrophils during pulmonary polymorphonuclear neutrophil activation and sequestration. The aim of the study was to investigate whether the inhibition of neutrophil elastase could lead to the restoration of pulmonary function following LT.

Methods

In in vivo experiments, lung tissue and bronchoalveolar lavage fluid (BALF) were collected at 2, 4, 8, and 24 h after rats were subjected to orthotopic autologous LT (OALT), and neutrophil infiltration was detected. Next, neutrophil elastase inhibitors, sivelestat sodium hydrate (exogenous) and serpin family B member 1 (SERPINB1) (endogenous), were administered to rats before OALT, and neutrophil infiltration, pulmonary oxidative stress, and barrier function were measured at 8 h after OALT.

Results

Obvious neutrophil infiltration occurred from 2 h and peaked at 8 h in the lungs of rats after they were subjected to OALT, as evidenced by an increase in naphthol-positive cells, BALF neutrophil elastase activity, and lung myeloperoxidase activity. Treatment with neutrophil elastase inhibitors, either sivelestat sodium hydrate or SERPINB1, effectively reduced lung naphthol-positive cells and BALF inflammatory cell content, increased expression of lung HO-1 and tight junction proteins ZO-1 and occludin, and increased the activity of superoxide dismutase.

Conclusion

Neutrophil elastase inhibitors, sivelestat sodium hydrate and SERPINB1, both reduced lung neutrophil infiltration and pulmonary oxidative stress and finally restored pulmonary barrier function.

Liver Transplantation from Voluntary Organ Donor System in China: A Comparison between DBD and DCD Liver Transplants

BACKGROUND

In China, the cases of liver transplantation (LT) from donation after citizens' death have rose year by year since the citizen-based voluntary organ donor system was initiated in 2010. The objective of our research was to investigate the early postoperative and late long-term outcomes of LT from donation after brain death (DBD) and donation after circulatory death (DCD) according to the current organ donation system in China.

METHODS

Sixty-two consecutive cases of LT from donation after citizens' death performed in our hospital between February 2012 and June 2017 were examined retrospectively for short- and long-term outcomes. These included 35 DCD LT and 27 DBD LT.

RESULT

Subsequent median follow-up time of 19 months and 1- and 3-year graft survival rates were comparative between the DBD group and the DCD group (81.5% and 66.7% versus 67.1% and 59.7%; P = 0.550), as were patient survival rates (85.2% and 68.7% versus 72.2% and 63.9%; P = 0.358). The duration of ICU stay of recipients was significantly shorter in the DBD group, in comparison with that of the DCD group (1 versus 3 days, P = 0.001). Severe complication incidence (≥grade III) after transplantation was identical among the DBD and DCD groups (48.1% versus 60%, P = 0.352). There was no significant difference in postoperative mortality between the DBD and DCD groups (3 of 27 cases versus 5 of 35 cases). Twenty-one grafts (33.8%) were lost and 18 recipients (29.0%) were dead till the time of follow-up. Malignancy recurrence was the most prevalent reason for patient death (38.8%). There was no significant difference in incidence of biliary stenosis between the DBD and DCD groups (5 of 27 cases versus 6 of 35 cases, P = 0.846).

CONCLUSION

Although the sample size was small to some extent, this single-center study first reported that LT from DCD donors showed similar short- and long-term outcomes with DBD donors and justified the widespread implementation of voluntary citizen-based deceased organ donation in China. However, the results should be verified with a multicenter larger study.

Is hospital-acquired pneumonia different in transplant recipients?

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are serious complications in transplant patients. The aim of this review is to summarize the evidence regarding nosocomial pneumonia in transplant recipients, including HAP in non-ventilated patients and VAP, and to identify future directions for improvement.A comprehensive literature search in the PubMed/MEDLINE database was performed. Articles written in English and published between 1990 and November 2018 were included. HAP/VAP in transplant patients usually occurs early post-transplant, particularly during neutropenia in haematopoietic stem cell transplant recipients. Bacteria are the leading cause of nosocomial pneumonia for both immunocompetent and transplant recipients, being Gram negative organisms, and especially Pseudomonas aeruginosa, highly prevalent. Multidrug-resistant bacteria are of special concern. Pneumonia in the transplant setting may be caused by opportunistic pathogens, and the differential diagnosis needs to be extended to other non-infectious complications. The most relevant opportunistic pathogens are Aspergillus fumigatus, Pneumocystis jirovecii and cytomegalovirus. Nevertheless, they are an exceptional cause of nosocomial pneumonia, and usually occur in severely immunosuppressed patients not receiving antimicrobial prophylaxis. Performing bronchoalveolar lavage may improve the rate of aetiological diagnosis, leading to a change in therapeutic management and improved outcomes. The optimal length of antibiotic therapy for bacterial HAP/VAP has not been well defined, but it should perhaps be longer than in the general population. Mortality associated with HAP/VAP is high. HAP/VAP in transplant patients is frequent and is associated with increased mortality. There is room for improvement in gaining knowledge about the management of HAP/VAP in this population.

The Incidence and Risk Factors of Low Oxygenation After Orthotropic Liver Transplantation

Background

This study was designed to observe incidence and risk factors of low oxygenation after orthotropic liver transplantation (OLT).

Material/Methods

We retrospectively evaluated all adult patients who underwent living-donor OLT between January 1, 2017 and December 31, 2017. Postoperative low oxygenation was defined as PaO₂/FiO₂ <300 mmHg within 24 hours after surgery. Early acute kidney injury (AKI) after OLT was also defined when AKI was happened with 24 hours after operative.

Results

A total of 301 patients, aged 50.35±10.29 years were enrolled. Of these patients, 100 patients (33.2%) suffered postoperative low oxygenation (PaO₂/FiO₂=251.80±35.84). Compared with the normal oxygenation group, body mass index (BMI) (24.48±3.53 versus 23.1±3.27 kg/m², P=0.001), preoperative hemoglobin (115.79±29.27 versus 111.52±29.80 g/L, P=0.033), preoperative MELD (22.25±6.54 versus 20.24±5.74, P=0.008), and intraoperative urinary volume (1.25 [0.76, 1.89] versus 2.04 [1.49, 3.68] mL/kg/h, P=0.003) were higher in low oxygenation group. There were more cases of earlier AKIs that occurred after OLT in low oxygenation patients than that in normal group (47% versus 23.4%, P<0.001). Logistic analysis showed that the preoperative BMI (hazard ration [HR]=1.107, [1.010, 1.212], P=0.029) and early AKI after OLT (HR=2.115, [1.161, 3.855], P=0.014) were independent risk factors for postoperative low oxygenation.

Conclusions

The incidence of postoperative low oxygenation after liver transplantation in adults was 33.2%. BMI and early AKI after OLT were correlated with postoperative hypoxemia.

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.

N-Acetylcysteine inhalation improves pulmonary function in patients received liver transplantation

Postoperative pulmonary complications (PPCs) following orthotopic liver transplantation (OLT) are associated with high morbidity and mortality rates. The effect of N-acetylcysteine (NAC) inhalation on the incidence of PPCs and the outcomes of patients undergoing OLT is unknown. This prospective randomized controlled clinical trial was conducted to investigate the effect of NAC inhalation during OLT on PPCs. Sixty patients were randomly assigned to the NAC group (n = 30) or the control group (n = 30) to receive inhaled NAC or sterilized water, respectively, for 30 min before surgery and 3 h after reperfusion. The incidence of early PPCs and outcomes including survival rate were assessed. Biomarkers including tumor necrosis factor (TNF)-α, interleukin (IL)-8, Clara cell secretory protein (CC16), intercellular adhesion molecule (ICAM)-1, and superoxide dismutase (SOD) were measured in exhaled breath condensate (EBC) at T1 (before surgery) and T2 (at the end of operation) as well as in serum at T1, T2, T3 (12 h after operation), and T4 (24 h after operation). A total of 42 patients (20 in the NAC group and 22 in the control group) were enrolled in the final analysis. Atomization inhaled NAC significantly reduced the incidence of PPCs after OLT. The levels of TNF-α, IL-8, CC16, and ICAM-1 in EBC were significantly lower, and SOD activity was higher, at T2 in the NAC group; similar data were found in serum at T2, T3, and T4. In summary, perioperative NAC inhalation may reduce the incidence of PPCs and improve patient outcomes after OLT.

Pulmonary Infections in Immunocompromised Hosts: Clinical

Pulmonary infections in immunocompromised patients remain a significant contributor to mortality, morbidity, and health care-associated costs in such a vulnerable patient population. Their epidemiology is changing, set forth by new trends in immunosuppressive regimens and also prophylaxis. The host characteristics, presenting clinical symptomatology, along with radiographic patterns, have also evolved. The microbiology diagnostics are now enriched with nonculture methods for better identification of the causative pathogens. Chest imaging remains the cornerstone of the initial workup. Our article will examine the new trends in epidemiology, clinical findings, and diagnostics for immunocompromised patients with pulmonary infections (transplant recipients, neutropenic hosts, HIV-infected patients, and patients with autoimmune conditions). We will also review the differential diagnosis that most of the times includes malignancies and drug or radiation-related toxicities.

Pulmonary complications after liver transplantation in children: risk factors and impact on early post-operative morbidity

Liver transplantation (LT) is associated with high post-operative morbidity, despite excellent survival rates. With this retrospective study, we report the incidence of early and late pulmonary complications (PC) after LT, identify modifiable risk factors for PC and analyzed the role of PC in post-operative ventilation duration and hospital length of stay. In a series of 79 children (0-16 years) with LT over a 12 years period, early (<3 months post-LT) and/or late (>3 months post-LT) PC occurred in 68 patients (86%). Sixty-four percent (64%) developed early major complications such as pulmonary edema, atelectasis, or pleural effusion. Atelectasis requiring an intervention (P ≤ .02), pulmonary edema (P ≤ .02), or elevated PELD/MELD scores (P = .05) were associated with an increase in total ventilation duration and length of stay in the ICU. Risk factors for early PC included preoperative hypoxemia (P = .005), low serum albumin at LT admission (P = .003), or early rejection (P = .002). About 20% of patients experienced late PC of which 81% were infections. Risk factor assessment prior to LT may ultimately help reduce early PC thereby possibly minimizing post-operative morbidity and ICU length of stay.

Noninfectious Pulmonary Complications of Liver, Heart, and Kidney Transplantation: An Update

Despite significant advances in surgical techniques, perioperative care, and immunosuppressive therapy, solid organ transplantation still carries considerable risk of complications. Pulmonary complications, in particular, are a major cause of morbidity and mortality. Although infectious complications prevail, the lungs are also vulnerable to a variety of noninfectious complications related to the transplant surgery and adverse effects of the immunosuppressive regimen. This article focuses on noninfectious pulmonary complications associated with the 3 most commonly performed solid organ transplant procedures: liver, kidney, and heart.

SERPINB1 ameliorates acute lung injury in liver transplantation through ERK1/2-mediated STAT3-dependent HO-1 induction

BACKGROUND

Postoperative acute lung injury (ALI) is a severe complication after liver transplantation, which severely affects postoperative patients' survival. The underlying mechanism is largely unknown and effective treatment limited. We explored the role of serpin protease inhibitor B1 (SERPINB1), a potent inhibitor of neutrophil serine proteases, in ALI in liver transplantation and its interplay with signal transducer and activator of transcription 3 (STAT3) and heme oxygenase-1 (HO-1).

METHODS

Sprague-Dawley rats underwent orthotopic autologous liver transplantation (OALT) were treated with recombinant SB1 (rSB1) in the absence or presence of STAT3 specific inhibitor, WP1066. Then SB1-siRNA was used to knockdown endogenous SERPINB1. Also, alveolar epithelial cells RLE-6TN and BEAS-2B were exposed to TNF-α without or with SERPINB1 and the roles of STAT3 and HO-1 were examined by respective gene knockdown. Finally, rats were treated with ERK1/2 inhibitor U0126, p38 MAPK inhibitor SB20358, or JNK inhibitor SP600125 after rSB1 pretreatment and then subjected to OALT.

RESULTS

OALT resulted in increased pulmonary inflammation and oxidative stress, accompanied by severe lung injury that was coincident with increased pulmonary SERPINB1, HO-1, and STAT3. SERPINB1 gene knockdown increased post-OALT lung injury and pulmonary inflammation. rSB1 administration dose-dependently reduced post-OALT lung injury and decreased pulmonary inflammation and oxidative stress with concomitant enhanced HO-1 and STAT3 protein expression. These protective effects of SERPINB1 were abolished by STAT3 inhibition. Similarly, in RLE-6TN cells and BEAS-2B cells, TNF-α induced cell injury and increased HO-1 and STAT3. SERPINB1 further increased HO-1 and STAT3 protein expression and attenuated TNF-α-induced cellular oxidative stress, apoptotic cells, and mitochondria damage, which were cancelled by STAT3 or HO-1 gene knockdown. Furthermore, these SERPINB1-mediated STAT3/HO-1 activation and pulmonary protective effects were abolished by inhibition of ERK1/2 but not p38 MAPK or JNK.

CONCLUSIONS

SERPINB1 decreased inflammation, ameliorated oxidative stress in the lung, and attenuated ALI in rats with OALT by activating HO-1 and it does so through STAT3 and it does so by activating ERK1/2.

Pretransplant Factors and Associations with Postoperative Respiratory Failure, ICU Length of Stay, and Short-Term Survival after Liver Transplantation in a High MELD Population

Changes in distribution policies have increased median MELD at transplant with recipients requiring increasing intensive care perioperatively. We aimed to evaluate association of preoperative variables with postoperative respiratory failure (PRF)/increased intensive care unit length of stay (ICU LOS)/short-term survival in a high MELD cohort undergoing liver transplant (LT). Retrospective analysis identified cases of PRF and increased ICU LOS with recipient, donor, and surgical variables examined. Variables were entered into regression with end points of PRF and ICU LOS > 3 days. 164 recipients were examined: 41 (25.0%) experienced PRF and 74 (45.1%) prolonged ICU LOS. Significant predictors of PRF with univariate analysis: BMI > 30, pretransplant MELD, preoperative respiratory failure, LVEF < 50%, FVC < 80%, intraoperative transfusion > 6 units, warm ischemic time > 4 minutes, and cold ischemic time > 240 minutes. On multivariate analysis, only pretransplant MELD predicted PRF (OR 1.14, p = 0.01). Significant predictors of prolonged ICU LOS with univariate analysis are as follows: pretransplant MELD, FVC < 80%, FEV1 < 80%, deceased donor, and cold ischemic time > 240 minutes. On multivariate analysis, only pretransplant MELD predicted prolonged ICU LOS (OR 1.28, p < 0.001). One-year survival among cohorts with PRF and increased ICU LOS was similar to subjects without. Pretransplant MELD is a robust predictor of PRF and ICU LOS. Higher MELDs at LT are expected to increase need for ICU utilization and modify expectations for recovery in the immediate postoperative period.

Propofol attenuated liver transplantation-induced acute lung injury via connexin43 gap junction inhibition

BACKGROUND

Postoperative acute lung injury (ALI) is a severe complication after liver transplantation, which influences patient survival rate obviously. However, its mechanisms are unclear and effective therapies are still lacking. The current study focused on effects of propofol on liver transplantation-induced ALI and whether its underlying mechanism was relative with connexin43 (Cx43) alternation. The authors postulated that endotoxin induced enhancement of Cx43 gap junction (GJ) plays a critical role in mediating post liver transplantation ALI and that pretreatment with the anesthetic propofol, known to inhibit gap junction, can confer effective protection.

METHODS

Male Sprague-Dawley rats underwent autologous orthotopic liver transplantation (AOLT) in the absence or presence of treatments with the selective Cx43 inhibitor, enanthol (0.1 mg/kg) and propofol (50 mg/kg), a commonly used anesthetic in clinical anesthesia. In vitro study, BEAS-2B cells, a kind of lung epithelial cell line expressing Cx43, exposed to lipopolysaccharide (LPS), which mainly contributed to ALI. Function of Cx43 GJ was regulated by Cx43 specific inhibitors, gap26 (300 μM) or enhancer, retinoic acid (10 μM) and two specific siRNAs.

RESULTS

Compared with the sham group, AOLT results in ALI obviously with plasma endotoxin increase. Cx43 inhibition decreased ALI through inflammatory reaction reduction. In vitro studies, LPS-induced BEAS-2B cells damage was attenuated by Cx43 function inhibition, but amplified by enhancement. Another important finding was propofol reduced Cx43 function and protected against LPS-mediated BEAS-2B cells damage or AOLT-induced ALI, mechanisms of which were also associated with inflammatory reaction decrease.

CONCLUSION

Cx43 plays a vital role in liver transplantation-induced ALI. Propofol decreased Cx43 function and protected against ALI in vivo and in vitro. This finding provide a new basis for targeted intervention of organ protection in liver transplantation, even in other kinds of operations.

Induction of heme oxygenase-1 by hemin protects lung against orthotopic autologous liver transplantation-induced acute lung injury in rats

BACKGROUND

Post-liver transplantation acute lung injury (ALI) severely affects patients' survival, whereas the mechanism is unclear and effective therapy is lacking. The authors postulated that reperfusion-induced increased oxidative stress plays a critical role in mediating post-liver transplantation ALI and that induction of heme oxgenase-1 (HO-1), an enzyme with anti-oxidative stress properties, can confer effective protection of lung against ALI.

METHODS

Male Sprague-Dawley rats underwent autologous orthotopic liver transplantation (OALT) in the absence or presence of treatments with the selective HO-1 inducer (Hemin) or HO-1 inhibitor (ZnPP). Lung tissues were collected at 8 h after OALT, pathological scores and lung water content were evaluated; survival rate of rats was analyzed; protein expression of HO-1 was determined by western blotting, and nuclear translocation of Nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor(NF)-κB p65 were detected by Immunofluorescence staining. The inflammatory cytokines and oxidative indexes of lung tissue were determined.

RESULTS

In lungs harvested at the early stage i.e. 8 h after OALT, Hemin treatment significantly increased superoxide dismutase activities, and reduced malondialdehyde, hydrogen peroxide, interleukin-6, myeloperoxidase, and tumor necrosis factor-α production,which were associated with increased HO-1 protein expression and lower pathological scores and increased survival rate of rats. The underline mechanisms might associate with activation of Nrf2 and inhibition of NF-κB p65 nuclear translocation. However, these changes were aggravated by ZnPP.

CONCLUSIONS

Hemin pretreatment, by enhancing HO-1 induction, increased lung antioxidant capacity and reduced inflammatory stress,protected the lung from OALT-induced ALI at early stage of reperfusion.

Melatonin prevents lung injury induced by hepatic ischemia-reperfusion through anti-inflammatory and anti-apoptosis effects

Melatonin is a free radical scavenger and broad-spectrum antioxidant with immunomodulatory effects. The objective of the study is to investigate the effects of melatonin in hepatic ischemia/reperfusion (I/R) induced lung injury and explore its underlying mechanisms. Hepatic I/R injury was induced via portal vein and hepatic artery occlusion for 30min followed by 3-h reperfusion. Male Sprague-Dawley rats were divided into three groups: sham, I/R+ Vehicle and I/R+melatonin. Melatonin (10mg/kg) or vehicle was injected intravenously 15min before ischemia and 10min before reperfusion. The histology of the liver and lung, plasma aminotransferase and cytokine secretion, and apoptosis in the lung were evaluated. The phosphorylation of JNK, p38, and NF-ƙB and Nrf2 nuclear translocation in the lung was examined by Western blotting. We found that melatonin administration significantly attenuated hepatic I/R induced lung injury in rats. Melatonin inhibited the pro-inflammatory responses and enhanced antioxidative responses. Melatonin alleviated pathological changes of the lung and liver, and inhibited apoptosis of cells in the lung. Phosphorylation of JNK, p38 and NF-ƙB and Nrf2 nuclear translocation was increased significantly in the lung by hepatic I/R. Melatonin administration inhibited the activation of JNK, p38, and NF-ƙB, however, melatonin further enhanced Nrf2 activation. We conclude that melatonin exerts a protective effect in hepatic I/R induced lung injury by attenuating the pro-inflammatory responses, inhibiting cell apoptosis, which was mediated in part through JNK, p38 MAPK, NF-ƙB and Nrf2 signaling pathways. Melatonin may be a promising therapeutic strategy for hepatic I/R induced lung injury.

Risk of Respiratory Complications in Obese Liver Transplant Patients: A Study of 343 Patients

INTRODUCTION

Obesity is a risk factor that increases the number of complications after orthotopic liver transplantation (LT). We sought to analyze the short-term respiratory complications in obese LT recipients and compare them with a control group of nonobese patients.

MATERIAL AND METHODS

A retrospective analysis of LT patients in a hospital in the southeast of Spain (2007-2013), selecting the study cases using a body mass index (BMI) of >30 kg/m(2) and a control group (BMI < 30). Study variables were age, sex, indication for LT, demographic and clinical variables, respiratory complications during the first postoperative month, and mortality rate secondary to respiratory disease.

RESULTS

Of the 343 LT recipients, 74 were obese (21.6%): 59 patients had a BMI between 30 and 35 (grade I obesity) and among them, 5% presented with respiratory complications, with a 33% mortality rate. Fifteen patients had a BMI of >35 (obesity grade II), and 20% presented with respiratory complications, with a 33% mortality rate. In the control group (n = 30), 17% experienced respiratory complications and there was a 20% mortality rate. There were no differences in respiratory complications between the obese and nonobese groups, or the different kinds of obesity (P > .05).

CONCLUSIONS

There were no differences in short-term respiratory complications between obese LT recipients and those with a normal weight.

Downregulation of Lung Toll-Like Receptor 4 Could Effectively Attenuate Liver Transplantation-Induced Pulmonary Damage at the Early Stage of Reperfusion

Acute lung injury (ALI) is a severe complication of orthotopic liver transplantation (OLT) with unclear underline mechanism. Toll-like receptor 4 (TLR4) has been identified as a key receptor mediating inflammation. We hypothesized that TLR4-mediated pulmonary inflammation may contribute to development of ALI during OLT. Patients with or without ALI were observed for serum cytokines and expression of TLR4 on peripheral blood polymorphonuclear leukocytes (PMNs). Next, rats which underwent orthotopic autologous liver transplantation (OALT) were divided into sham and model groups. Pulmonary function and the level of TLR4 expression and cytokines were analyzed. Furthermore, the role of TLR4 in OALT-mediated ALI was assessed in rats treated with TLR4-siRNA before OALT. The PMNs TLR4 expression and the serum TNF-α and IL-β level were higher in patients with ALI than those with non-ALI. Interestingly, lung TLR4 expression was significantly increased after 8 hours of OALT with increased levels of TNF-α and IL-β, which lead to lung pathological damage and an increase of lung myeloperoxidase content. Moreover, knockdown of TLR4 reduced lung cytokines release and reversed the above pathologic changes after OALT and finally improved rats' survival rate. In conclusion, TLR4 overexpression, potentially by stimulating proinflammatory cytokine overproduction, contributes to the development of ALI after OLT.

Dexmedetomidine ameliorates acute lung injury following orthotopic autologous liver transplantation in rats probably by inhibiting Toll-like receptor 4-nuclear factor kappa B signaling

BACKGROUND

To investigate whether pretreatment with dexmedetomidine (Dex) has a protective effect against acute lung injury (ALI) in an orthotopic autologous liver transplantation (OALT) rat model and to explore the mechanisms responsible for the protective effect of Dex against lung injury.

METHODS

Forty-eight rats underwent OALT and were randomly divided into six groups (n = 8 in each group) that received 10 µg/kg Dex, 50 µg/kg Dex, 50 µg/kg Dex + nonspecific α2-adrenergic receptor (AR) antagonist atipamezole, 50 µg/kg Dex + specific α2B/C-AR antagonist ARC-239, 50 µg/kg Dex + specific α2A-AR antagonist BRL-44408, or the same amount of normal saline. The sham rats (n = 8) underwent anesthesia induction, laparotomy, and separation of the portal vein without liver ischemia and reperfusion. Lung tissue sections were stained with hematoxylin and eosin (HE) to visualize the damage. The expression of Toll-like receptor 4 (TLR4) and the phospho-nuclear factor (NF)-κB p65 subunit as well as inflammatory cytokines was measured.

RESULTS

Rats exhibited increased histological lung injury scores and pulmonary edema following OALT. Pretreatment with 50 μg/kg Dex attenuated OALT-induced lung injury in rats, probably by inhibiting the activation of the TLR4-NF-κB signaling pathway. The protective effect of Dex could be blocked by atipamezole or BRL-44408, but not by ARC-239, suggesting these effects of Dex were mediated, at least in part, by the α2A-AR.

CONCLUSIONS

Dex exerts protective effects against ALI following OALT, and this protection is associated with the suppression of TLR4-NF-κB signaling. Thus, pretreatment with Dex may be a useful method for reducing lung damage caused by liver transplantation.

Postoperative Pulmonary Complications After Liver Transplantation: Assessment of Risk Factors for Mortality

BACKGROUND

The aim of this study was to identify the risk factors related to mortality in liver transplant (LT) patients with post-transplantation pulmonary complications.

METHOD

Patients who underwent liver transplantation in our clinic between January 2010 and January 2012 were retrospectively reviewed for post-transplantation pulmonary complications. Demographic, clinical, radiologic, and postoperative chart data of 153 patients with pulmonary complications were analyzed using an independent samples Student t test, Pearson's χ(2) test, Fisher's exact test, and Yate's corrected χ(2) test. Mortality was analyzed using a multiple logistic regression model. The best-fit breakpoint resulting in a cut-off value for the variables of interest was determined using ROC curves and the Youden index.

RESULTS

The 153 patients with pulmonary complication were divided into 2 groups: mortality (n = 53) and survival (n = 100). Univariate analyses showed significant differences between these 2 groups with respect to MELD score (P = .035), duration of mechanical ventilation (P > .001), pneumonia (P = .01), and endotracheal culture results (P = .001). In the multivariate analysis, hemoglobin (P = .03, odds ratio [OR]: 1.239), MELD score (P = .027, OR: 1.064), duration of mechanical ventilation (P = .003, OR: 1.091), and age (P = .042, OR: 1.001) were significant risk factors for mortality. The best-fit breakpoint analysis yielded cut-off values for hemoglobin (>11.2, sensitivity: 50.9%, specificity: 70%), MELD score (>16, sensitivity: 73.6%, specificity: 42%) and duration of mechanical ventilation (>3, sensitivity: 62.3%, specificity: 76%).

CONCLUSION

Advanced age, high hemoglobin level, high MELD score, and long-term mechanical ventilation are significant risk factors for mortality in liver transplant patients with postoperative pulmonary complications.

Ulinastatin prevents acute lung injury led by liver transplantation

BACKGROUND

Little is known regarding the effect of ulinastatin (UTI) on acute lung injury (ALI) induced by orthotopic liver transplantation. This study aims to investigate the protective effect of UTI on ALI induced by orthotopic autologous liver transplantation (OALT) in a rat model and to explore the potential underlying mechanism.

MATERIALS AND METHODS

Rats were randomly allocated into the following four groups (n = 8 each): (i) sham control group (group sham); (ii) model group (underwent OALT) (group model); (iii) low-dose UTI-treated group (group u1), with UTI (50 U/g) administered intravenously both before the portal vein was occluded and after liver reperfusion started; and (iv) high-dose UTI-treated group (group uh), with UTI (100 U/g) given in the same way as group ul. The lung pathologic parameters, lung water content, and levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, malondialdehyde (MDA), superoxide dismutase (SOD) activity, RanBP-type and C3HC4-type zinc finger-containing protein 1 (RBCK1), and peroxiredoxin-2 (Prx-2) were assessed 8 h after OALT was performed.

RESULTS

According to histology, there was severe damage in the lung of group model accompanied by increases in the TNF-α, IL-1β, IL-6, and MDA levels and decreases in SOD activity and the expression of RBCK1 and Prx-2. UTI treatment significantly reduced the pathologic scores, lung water content, and TNF-α, IL-1β, IL-6, and MDA levels while restoring the SOD activity and expression of RBCK1 and Prx-2. Furthermore, compared with group u1, treatment with a high dose of UTI resulted in a better protective effect on the lung when assessed by the TNF-α, IL-1β, IL-6, and MDA levels and SOD activity.

CONCLUSIONS

UTI dose-dependently attenuates ALI that is induced by OALT in this rat model, which is mainly due to the suppression of the inflammatory response and oxidant stress, which may, in turn, be mediated by the upregulation of RBCK1 and Prx-2 expression.

Global consequences of liver ischemia/reperfusion injury

Liver ischemia/reperfusion injury has been extensively studied during the last decades and has been implicated in the pathophysiology of many clinical entities following hepatic surgery and transplantation. Apart from its pivotal role in the pathogenesis of the organ's post reperfusion injury, it has also been proposed as an underlying mechanism responsible for the dysfunction and injury of other organs as well. It seems that liver ischemia and reperfusion represent an event with “global” consequences that influence the function of many remote organs including the lung, kidney, intestine, pancreas, adrenals, and myocardium among others. The molecular and clinical manifestation of these remote organs injury may lead to the multiple organ dysfunction syndrome, frequently encountered in these patients. Remote organ injury seems to be in part the result of the oxidative burst and the inflammatory response following reperfusion. The present paper aims to review the existing literature regarding the proposed mechanisms of remote organ injury after liver ischemia and reperfusion.

Propofol activation of the Nrf2 pathway is associated with amelioration of acute lung injury in a rat liver transplantation model

Objective. This study aimed to investigate whether propofol pretreatment can protect against liver transplantation-induced acute lung injury (ALI) and to explore whether Nrf2 pathway is involved in the protections provided by propofol pretreatment. Method. Adult male Sprague-Dawley rats were divided into five groups based on the random number table. Lung pathology was observed by optical microscopy. Lung water content was assessed by wet/dry ratio, and PaO₂ was detected by blood gas analysis. The contents of H₂O₂, MDA, and SOD activity were determined by ELISA method, and the expression of HO-1, NQO1, Keap1, and nuclear Nrf2 was assayed by western blotting. Results. Compared with saline-treated model group, both propofol and N-acetylcysteine pretreatment can reduce the acute lung injury caused by orthotopic autologous liver transplantation (OALT), decrease the lung injury scores, lung water content, and H₂O₂ and MDA levels, and improve the arterial PaO₂ and SOD activity. Furthermore, propofol (but not N-acetylcysteine) pretreatment especially in high dose inhibited the expression of Keap1 and induced translocation of Nrf2 into the nucleus to further upregulate the expression of HO-1 and NQO1 downstream. Conclusion. Pretreatment with propofol is associated with attenuation of OALT-induced ALI, and the Nrf2 pathway is involved in the antioxidative processes.

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.

Predictive Factors for Reintubation following Noninvasive Ventilation in Patients with Respiratory Complications after Living Donor Liver Transplantation

Background

Postoperative respiratory complications are a major cause of mortality following liver transplantation (LT). Noninvasive ventilation (NIV) appears to be effective for respiratory complications in patients undergoing solid organ transplantation; however, mortality has been high in patients who experienced reintubation in spite of NIV therapy. The predictors of reintubation following NIV therapy after LT are not exactly known.

Methods

Of 511 adult patients who received living-donor LT, data on the 179 who were treated by NIV were retrospectively examined.

Results

Forty-three (24%) of the 179 patients who received NIV treatment required reintubation. Independent factors associated with reintubation by multivariate logistic regression analysis were controlled preoperative infections (odds ratio [OR] 8.88; 95% confidence interval (CI) 1.64 to 48.11; p = 0.01), ABO-incompatibility (OR 4.49; 95% CI, 1.50 to 13.38; p = 0.007), and presence of postoperative pneumonia at the time of starting NIV (OR 3.28; 95% CI, 1.02 to 11.01; p = 0.04). The reintubated patients had a significant higher rate of postoperative infectious complications and a significantly longer intensive care unit stay than those in whom NIV was successful (p<0.0001). Of the 43 reintubated patients, 22 (51.2%) died during hospitalization following LT vs. 8 (5.9%) of the 136 patients in whom NIV was successful (p<0.0001).

Conclusions

Because controlled preoperative infection, ABO-incompatibility or pneumonia prior to the start of NIV were independent risk factors for reintubation following NIV, caution should be used in applying NIV in patients with these conditions considering the high rate of mortality in patients requiring reintubation following NIV.

Septic pulmonary embolism originated from subcutaneous abscess after living donor liver transplantation: a pitfall of postoperative management

The use of immunosuppressants after liver transplantation (LT) is associated with postoperative complications, including infections. A 49-year-old male underwent living-donor (LD) LT because of primary sclerosing cholangitis. He was treated with tacrolimus, mycophenolate mofetil, and steroids as immunosuppressants, discharged on postoperative day (POD) 40, and re-admitted because of severe acute cellular rejection on POD 48. Three courses of steroid pulse therapy were performed, and continuous peripheral intravenous drip infusion therapy via the left forearm was necessary for 20 days because of appetite loss. The patient was discharged on POD 83, but re-admitted on POD 87 with pyrexia. A subcutaneous abscess was present at a puncture wound on the left forearm formed by an intravenous drip during the last hospital stay. Furthermore, computed tomography showed five pieces of cavitary or wedge-shaped nodules in the bilateral lung. Because sputum revealed the presence of Gram-positive coccus, and subcutaneous abscess and blood cultures revealed Staphylococcus aureus, the pathogenesis was septic pulmonary embolism (SPE) secondary to S. aureus septicemia originating from a subcutaneous abscess formed by an intravenous drip. The patient was treated with drainage of the subcutaneous abscess and antibiotic therapy, and recovered immediately. Although there have been few reports of SPE after LDLT, SPE is fatal in up to 13.3 % of patients. Early diagnosis, drainage of the infectious source, and appropriate use of antimicrobial therapy should be necessary to overcome SPE. Furthermore, the identical intravenous catheters should be removed whenever possible to avoid infectious complications including SPE for patients who receive steroid pulse therapy after LDLT.