A benchmark for Monte Carlo simulations in gamma-ray spectrometry Part II: True coincidence summing correction factors

The goal of this study is to provide a benchmark for the use of Monte Carlo simulation when applied to coincidence summing corrections. The examples are based on simple geometries: two types of germanium detectors and four kinds of sources, to mimic eight typical measurement conditions. The coincidence corrective factors are computed for four radionuclides. The exercise input files and calculation results with practical recommendations are made available for new users on a dedicated webpage.

Reducing Carbapenem-Resistant Enterobacteriaceae Using the Targeted Solution Tool: A Quality Improvement Project

BACKGROUND

Carbapenem-resistant Enterobacteriaceae (CRE) is a worldwide urgent health problem. Hand hygiene (HH) is an effective intervention to reduce the spread of CRE.

LOCAL PROBLEM

In 2017, an increase in the rate of health care-associated (HA) CRE colonization was observed in a large multiorgan transplant center in Italy. This study aimed to reduce the HA-CRE colonization rates by improving HH compliance.

METHODS

A pre-/post-intervention project was conducted from November 2017 through December 2020.

INTERVENTIONS

The DMAIC (Define, Measure, Analyze, Improve, and Control) framework was used to implement the HH Targeted Solution Tool (TST).

RESULTS

Hand hygiene compliance increased from 49% to 76.9% after the Improve phase ( P = .0001), and to 81.9% after the second Control phase ( P = .0001). The rate of HA-CRE decreased from 24.9% to 5.6% ( P = .0001).

CONCLUSIONS

Using the DMAIC framework to implement the TST can result in significant improvements in HH compliance and HA-CRE colonization rates.

Donor Simvastatin Treatment Is Safe and Might Improve Outcomes After Liver Transplantation: A Randomized Clinical Trial

BACKGROUND

The current curative approaches for ischemia/reperfusion injury on liver transplantation are still under debate for their safety and efficacy in patients with end-stage liver disease. We present the SIMVA statin donor treatment before Liver Transplants study.

METHODS

SIMVA statin donor treatment before Liver Transplants is a monocentric, double-blind, randomized, prospective tial aiming to compare the safety and efficacy of preoperative brain-dead donors' treatment with the intragastric administration of 80 mg of simvastatin on liver transplant recipient outcomes in a real-life setting. Primary aim was incidence of patient and graft survival at 90 and 180 d posttransplant; secondary end-points were severe complications.

RESULTS

The trial enrolled 58 adult patients (18-65 y old). The minimum follow-up was 6 mo. No patient or graft was lost at 90 or 180 d in the experimental group (n = 28), whereas patient/graft survival were 93.1% ( P = 0.016) and 89.66% ( P = 0.080) at 90 d and 86.21% ( P = 0.041) and 86.2% ( P = 0.041) at 180 d in the control group (n = 29). The percentage of patients with severe complications (Clavien-Dindo ≥IIIb) was higher in the control group, 55.2% versus 25.0% in the experimental group ( P = 0.0307). The only significant difference in liver tests was a significantly higher gamma-glutamyl transferase and alkaline phosphatase at 15 d ( P = 0.017), ( P = 0.015) in the simvastatin group.

CONCLUSIONS

Donor simvastatin treatment is safe, and may significantly improve early graft and patient survival after liver transplantation, although further research is mandatory.

How to Improve Patients' Perceived Quality of Sleep During Hospitalization Through a Multicomponent "Good Sleep Bundle": A Prospective Before and After Controlled Study

Introduction

Despite sound evidence on the importance of sleep for human beings and its role in healing, hospitalized patients still experience sleep disruption with deleterious effects. Many factors affecting patients' sleep can be removed or minimized. We evaluated the efficacy of a multicomponent Good Sleep Bundle (GSB) developed to improve patients' perceived quality of sleep, through which we modified environmental factors, timing of nighttime clinical interventions, and actively involved patients in order to positively influence their experience during hospitalization.

Methods

In a prospective, before and after controlled study, two different groups of 65 patients each were admitted to a cardiothoracic unit in two different periods, receiving the usual care (control group) and the GSB (GSB group), respectively. Sleep quality was evaluated by the Pittsburgh Sleep Quality Index (PSQI) at the admission, discharge, and 30 days after discharge in all patients enrolled. Comparisons between the two groups evaluated changes in PSQI score from admission to discharge (primary endpoint), and from admission to 30 days after discharge (secondary endpoint).

Results

The mean PSQI score difference between admission and discharge was 4.54 (SD 4.11) in the control group, and 2.05 (SD 4.25) in the GSB group. The mean difference in PSQI score change between the two groups, which was the primary endpoint, was 2.49 (SD 4.19). This difference was highly significant (p = 0.0009).

Conclusion

The GSB was associated with a highly significant reduction of the negative effects that hospitalization produces on patients' perceived quality of sleep compared with the usual care group.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Molecular Analysis With 16S rRNA PCR/Sanger Sequencing and Molecular Antibiogram Performed on DNA Extracted From Valve Improve Diagnosis and Targeted Therapy of Infective Endocarditis: A Prospective Study

BACKGROUND

Molecular analysis (MA) on heart valve (HV) improves the microbiologic diagnosis of infectious endocarditis (IE). The main drawback of MA is the lack of antimicrobial susceptibility information.

METHODS

We conducted a prospective cohort observational study of consecutive adult patients from April 2012 to May 2021 who underwent valve surgery at our hospital. The performance of MA, blood cultures (BC) and valve cultures (VC), and the diagnostic and therapeutic impact of MA were evaluated. Molecular antibiogram results were compared to culture-based antimicrobial susceptibility testing (AST).

RESULTS

A total of 137 patients with definite IE and 52 patients with no IE were enrolled in the study. Among IE cases BC, VC, and MA were positive in 75 (55%), 30 (22%), and 120 (88%) of IE cases, respectively. Among 62 cases of BC-negative IE (BCNE), 57 achieved diagnosis with MA. MA led to a change of antimicrobial therapy in 92% of BCNE. MA was negative in 100% of patients with no IE. Molecular antibiogram performed on 17 valve specimens that resulted positive for pathogens potential carrier of genes encoding for multidrug resistant mechanisms showed 100% concordance with AST.

CONCLUSIONS

MA showed a high specificity and sensitivity in etiological diagnosis of IE. Molecular antibiogram could overcome the major limitation of MA that is the lack of susceptibility testing. We advocate for the inclusion of MA among diagnostic criteria for IE and for a more extensive use of molecular antibiogram when the culture result is negative, and MA is the only positive test.

An automatic single beat algorithm to discriminate farfield from nearfield bipolar voltage electrograms from the pulmonary veins

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): “Stiftung für Herzschrittmacher und Elektrophysiologie” Basel, Switzerland

Background

Confirmation of pulmonary vein (PV) isolation (PVI) during ablation of atrial fibrillation can be challenging due to superimposition of nearfield (NF) PV and farfield (FF) atrial bipolar voltage electrograms (BVE).

Purpose

To develop an automatic algorithm allowing to discriminate PV nearfield (PV-NF) from atrial farfield (atrial-FF) BVE from a circular mapping catheter during cryoballoon (CB) PVI based on a single-heartbeat analysis.

Methods

BVEs from a decapolar inner-lumen diagnostic catheter (Achieve, Medtronic) during CB PVI were manually classified as PV-NF, atrial-FF and combined FF-NF signal based on the characteristics and disappearance of the PV signal during isolation (Figure, upper row). BVE power spectra were computed using the fast Fourier transform (FFT) and the automatic classification of PV-NF, atrial-FF and combined FF-NF signals was performed using the power in different frequency bands (Figure, lower row). Support vector machine classifier was used to identify PV-NF BVE due to its highest predictive accuracy for the two classes PV-NF+ (PV-NF only and combined FF-NF) and PV-NF- (atrial-FF only). Validation of the approach was performed by comparison of a subset of 80 random samples, which were classified in addition by five experienced electrophysiologists.

Results

We analysed a dataset of 355 BVEs from 57 patients. The examples were balanced between the two classes PV-NF+ and PV-NF-. The mean duration (95% CI) of the BVE was 58 ms (26 to 86), 70 ms (50 to 100) and 94 ms (71 to 139) for PV NF, atrial-FF and combined FF-NF, respectively. The overall balanced accuracy including BVE from all PVs was 82.7% (95% CI: 80.3% to 85.1%). The analysis on individual PVs showed an accuracy of 96.6%, 85.2%, 80.8%, and 76.9% for the right inferior, right superior, left inferior and left superior PV, respectively. Validation of the algorithm in the subset of 80 patients showed a comparable accuracy, sensitivity and specificity in PV-NF detection between the automatic algorithm and the experienced electrophysiologists (82.8%, 89.2%, and 76.3%, compared to 85.2%, 91.9%, and 78.5%, respectively).

Conclusion

A reliable automatic based classification algorithm to identify PV-NF BVE could be developed based on a single-beat analysis. Real-time applications as well as using other electrode configurations may improve local signal interpretation.

Amplitude of fibrillatory wave correlates with long-term maintenance of sinus rhythm after ablation in persistent atrial fibrillation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Commission for Technology and Innovation (CTI), Switzerland

Background

Amplitude of fibrillatory wave (fWA) on surface ECG is regarded as a predictor of ablation outcome for atrial fibrillation (AF).

Purpose

We sought to investigate whether fWA and its changes during ablation predicts long-term maintenance of sinus rhythm (SR) after wide circumferential isolation of pulmonary veins (WPVI) in persistent AF (peAF).

Methods

41 patients (63±10 y, sustained AF 11±7 months) underwent a de-novo WPVI. A second WPVI was performed in patients with recurrent AF in order to provide complete PV disconnection. We defined "success" as patients who remained in SR after one or two procedures, and "failure" otherwise. 60-sec ECG signals devoid of QRST waves were recorded during the index ablation at baseline and at the end of ablation (end_WPVI, before cardioversion or conversion of AF into SR). fWA was computed on leads V1 and V6b (placed on the pts’ back) as the average difference between the upper and lower envelope of atrial ECG signals.

Results

Over a mean follow-up of 33±9 months, 30 patients remained free from AF (success group), while 11 patients had AF recurrence after 2 WPVIs (failure group). The clinical characteristics (e.g. age, body mass index, left atrial volume or duration in sustained AF) were similar between groups (p > 0.05). The success group displayed significantly higher fWA values at baseline and end_WPVI than that of the failure group (p<0.05, Panel A and B). No significant difference was found between baseline fWA values and those measured at end_WPVI (p > 0.05).

Conclusion

As fWA is independent of PVs contribution, it is a marker of atrial body remodelling. Low fWA values identify patients with peAF unresponsive to WPVI.

Impact of the Organizational Model Adopted during the COVID-19 Pandemic on the Perceived Safety of Intensive Care Unit Staff

BACKGROUND

The SARS-CoV-2 pandemic had a devastating health, social, and economic effect on the population. Organizational, technical and structural operations aimed at protecting staff, outpatients and inpatients were implemented in an Italian hospital with a COVID-19 dedicated intensive care unit. The impact of the organizational model adopted on the perceived safety among staff was evaluated.

METHODS

Descriptive, structured and voluntary, anonymous, non-funded, self-administered cross-sectional surveys on the impact of the organizational model adopted during COVID-19 on the perceived safety among staff.

RESULTS

Response rate to the survey was 67.4% (153 completed surveys). A total of 91 (59%) of respondents had more than three years of ICU experience, while 16 (10%) were employed for less than one year. Group stratification according to profession: 74 nurses (48%); 12 medical-doctors (7%); 11 physiotherapists (7%); 35 nurses-aides (22%); 5 radiology-technicians (3%); 3 housekeeping (1%); 13 other (8%). The organizational model implemented at ISMETT made them feel safe during their workday. A total of 113 (84%) agreed or strongly agreed with the sense of security resulting from the implemented measures. A vast majority of respondents perceived COVID-19 as a dangerous and deadly disease (94%) not only for themselves but even more as vectors towards their families (79%). A total of 55% of staff took isolation measures and moved away from their home by changing personal habits. The organizational model was perceived overall as appropriate (91%) to guarantee their health.

CONCLUSION

The vast majority of respondents perceived the overall model applied during an unexpected, emergency situation as appropriate.

Performance of the model for end-stage liver disease score for mortality prediction and the potential role of etiology

BACKGROUND & AIMS

Although the discriminative ability of the model for end-stage liver disease (MELD) score is generally considered acceptable, its calibration is still unclear. In a validation study, we assessed the discriminative performance and calibration of 3 versions of the model: original MELD-TIPS, used to predict survival after transjugular intrahepatic portosystemic shunt (TIPS); classic MELD-Mayo; and MELD-UNOS, used by the United Network for Organ Sharing (UNOS). We also explored recalibrating and updating the model.

METHODS

In total, 776 patients who underwent elective TIPS (TIPS cohort) and 445 unselected patients (non-TIPS cohort) were included. Three, 6 and 12-month mortality predictions were calculated by the 3 MELD versions: discrimination was assessed by c-statistics and calibration by comparing deciles of predicted and observed risks. Cox and Fine and Grey models were used for recalibration and prognostic analyses.

RESULTS

In the TIPS/non-TIPS cohorts, the etiology of liver disease was viral in 402/188, alcoholic in 185/130, and non-alcoholic steatohepatitis in 65/33; mean follow-up±SD was 25±9/19±21 months; and the number of deaths at 3-6-12 months was 57-102-142/31-47-99, respectively. C-statistics ranged from 0.66 to 0.72 in TIPS and 0.66 to 0.76 in non-TIPS cohorts across prediction times and scores. A post hoc analysis revealed worse c-statistics in non-viral cirrhosis with more pronounced and significant worsening in the non-TIPS cohort. Calibration was acceptable with MELD-TIPS but largely unsatisfactory with MELD-Mayo and -UNOS whose performance improved much after recalibration. A prognostic analysis showed that age, albumin, and TIPS indication might be used to update the MELD.

CONCLUSIONS

In this validation study, the performance of the MELD score was largely unsatisfactory, particularly in non-viral cirrhosis. MELD recalibration and candidate variables for an update to the MELD score are proposed.

LAY SUMMARY

While the discriminative performance of the model for end-stage liver disease (MELD) score is credited to be fair to good, its calibration, the correspondence of observed to predicted mortality, is still unsettled. We found that application of 3 different versions of the MELD in 2 independent cirrhosis cohorts yielded largely imprecise mortality predictions particularly in non-viral cirrhosis. Thus, we propose a recalibration and suggest candidate variables for an update to the model.

Liver transplantation from active COVID-19 donors: A lifesaving opportunity worth grasping?

COVID-19 pandemic dramatically impacted transplantation landscape. Scientific societies recommend against the use of donors with active SARS-CoV-2 infection. Italian Transplant Authority recommended to test recipients/donors for SARS-CoV-2-RNA immediately before liver transplant (LT) and, starting from November 2020, grafts from deceased donors with active SARS-CoV-2 infection were allowed to be considered for urgent-need transplant candidates with active/resolved COVID-19. We present the results of the first 10 LTs with active COVID-19 donors within an Italian multicenter series. Only two recipients had a positive molecular test at LT and one of them remained positive up to 21 days post-LT. None of the other eight recipients was found to be SARS-CoV-2 positive during follow-up. IgG against SARS-CoV-2 at LT were positive in 80% (8/10) of recipients, and 71% (5/7) showed neutralizing antibodies, expression of protective immunity related to recent COVID-19. In addition, testing for SARS-CoV-2 RNA on donors' liver biopsy at transplantation was negative in 100% (9/9), suggesting a very low risk of transmission with LT. Immunosuppression regimen remained unchanged, according to standard protocol. Despite the small number of cases, these data suggest that transplanting livers from donors with active COVID-19 in informed candidates with SARS-CoV-2 immunity, might contribute to safely increase the donor pool.

Combination of aztreonam, ceftazidime-avibactam and amikacin in the treatment of VIM-1 Pseudomonas aeruginosa ST235 osteomyelitis

We describe a challenging case of patient with metallo-beta-lactamase-producing Pseudomonas aeruginosa sternal osteomyelitis following aortic valve replacement with biological prosthesis. The strain exhibited a multidrug-resistance phenotype carrying the bla_VIM-1 gene and belonged to the high-risk clone sequence type ST235. The patient was successfully treated with surgical debridement plus antibiotic therapy with ceftazidime/avibactam, aztreonam, and amikacin. Time-kill curves showed that this triple antibiotic combination at 1 × MIC was strongly synergic after 8 h, achieving 99.9% killing and maintaining this until 48 h.

Effects of Early Placement of Transjugular Portosystemic Shunts in Patients With High-Risk Acute Variceal Bleeding: a Meta-analysis of Individual Patient Data

BACKGROUND & AIMS

Compared with drugs plus endoscopy, placement of transjugular portosystemic shunt within 72 hours of admission to the hospital (early or preventive transjugular intrahepatic portosystemic shunt [TIPS], also called preemptive TIPS) increases the proportion of high-risk patients with cirrhosis and acute variceal bleeding who survive for 1 year. However, the benefit of preemptive TIPS is less clear for patients with a Child-Pugh score of B and active bleeding (CP-B+AB). We performed an individual data meta-analysis to assess the efficacy of preemptive TIPS in these patients and identify factors associated with reduced survival of patients receiving preemptive TIPS.

METHODS

We searched publication databases for randomized controlled trials and observational studies comparing the effects of preemptive TIPS versus endoscopy plus nonselective beta-blockers in the specific population of high-risk patients with cirrhosis and acute variceal bleeding (CP-B+AB or Child-Pugh C, below 14 points), through December 31, 2019. We performed a meta-analysis of data from 7 studies (3 randomized controlled trials and 4 observational studies), comprising 1327 patients (310 received preemptive TIPS and 1017 received drugs plus endoscopy). We built adjusted models to evaluate risk using propensity score for baseline covariates. Multivariate Cox regression models were used to assess the factors associated with survival time. The primary endpoint was effects of preemptive TIPS versus drugs plus endoscopy on 1-year survival in the overall population as well as CP-B+AB and Child-Pugh C patients.

RESULTS

Overall, preemptive TIPS significantly increased the proportion of high-risk patients with cirrhosis and acute variceal bleeding who survived for 1 year, compared with drugs plus endoscopy (hazard ratio [HR] 0.443; 95% CI 0.323-0.607; P < .001). This effect was observed in CP-B+AB patients (HR 0.524; 95% CI 0.307-0.896; P = .018) and in patients with Child-Pugh C scores below 14 points (HR 0.374; 95% CI 0.253-0.553; P < .001). Preemptive TIPS significantly improved control of bleeding and ascites without increasing risk of hepatic encephalopathy in Child-Pugh C and CP-B+AB patients, compared with drugs plus endoscopy. Cox analysis of patients who received preemptive TIPS showed that patients could be classified into 3 categories for risk of death, based on age, serum level of creatinine, and Child-Pugh score. In each of these risk categories, preemptive TIPS increased the proportion of patients who survived for 1 year, compared with drugs plus endoscopy.

CONCLUSIONS

In a meta-analysis of data from 1327 patients with cirrhosis, acute variceal bleeding, and Child-Pugh score between 10 and 13 points or CP-B+AB, preemptive TIPS increased the proportion who survived for 1 year, in both subgroups separately, compared with drugs plus endoscopy.

Post-crisis debriefing: A tool for improving quality in the medical emergency team system

OBJECTIVES

To examine clinicians' perception of quality of technical and non-technical response to emergencies and application of post crisis debriefing.

DESIGN

Descriptive, anonymous, self-reporting survey on the needs and perception of a post-crisis debriefing implementation.

SETTING

Multi-specialist medical institute in Italy focused on solid organ transplantation and organ failure support.

MAIN OUTCOMES

Perception of application of guidelines and evaluation of debriefing implementation during in-hospital emergencies.

RESULTS

Response rate to the survey was 25% (148 health care workers). Of all respondents, 86% were employed >10 years, 75% were involved in ≤5 emergencies over the previous year. Resuscitation guidelines were considered fully applied by 55%; 64% of respondents considered the teaching programme as sufficient. Of all participants, 97% were aware of the importance of teamwork dynamics, 79% were aware of the importance of the personal performance, and 52% considered emergencies as valid opportunities for professional growth. Leadership was considered important by 45% of respondents; debriefing implemented by 41%, and considered a potentially useful tool by 85%.

CONCLUSION

Post-crisis debriefing is a way to diffuse self-reflective and life-long learning culture; it is perceived as a powerful tool for improving quality of the rapid response system by the vast majority of those surveyed.

Vitamin D levels in liver transplantation recipients and early postoperative outcomes: Prospective observational DLiverX study

BACKGROUND & AIMS

In critically ill patients with liver disease, vitamin D deficiency is associated with higher disease severity, increased frequency of infections, and worse outcomes. This study sought to describe the trend of vitamin D in orthotopic liver transplantation (OLT) recipients and its association with outcomes.

METHODS

Prospective observational study of 67 consecutive OLT recipients enrolled between September, 2016 and August, 2017 at IRCCS-ISMETT, Palermo (Italy). Trend of vitamin D levels and potential factors influencing it levels were evaluated through a generalized linear mixed regression model.

RESULTS

Sixty-four (95.5%) recipients were vitamin D deficient (<20 ng/ml), with a median value of 8.8 ng/ml [6.2-12.9], and forty-seven of these (70.1%) showed severe deficiency (<12 ng/ml) at baseline, 7.9 ng/ml [5.4-8.9]. The baseline vitamin D showed an inverse correlation with liver disease severity: Child-Pugh, MELD score, bilirubin, INR, and organ failure (p < 0.01) at baseline. Vitamin D increased on postoperative day (POD) 28 compared with POD1: +4.5 ng/ml, C.I. 95% 3.6-5.3 ng/ml, p < 0.01. Lower baseline vitamin D, donor age, transfusion of fresh frozen plasma (negative impact, all p < 0.05), and intra-operative bypass (positive impact at POD 28, p < 0.01) were associated with variation of vitamin D levels after transplantation. Incomplete graft recovery was associated with lower vitamin D on POD28: 8.2 ± 4.4 versus 13.8 ± 9.4 ng/ml, p < 0.01; the odds ratio (OR) was 0.84; CI 95% 0.73-0.97, p = 0.014. The OR for infections within POD 28 was inversely associated with baseline vitamin D: 0.87; CI 95% 0.79-0.98, p = 0.02, and with vitamin D level at baseline <12 ng/ml: OR 6.44; CI 95% 1.66-24.94; p < 0.01.

CONCLUSIONS

Preoperative Vitamin D is correlated with disease severity, and was highly associated with invasive infection in the first 28 PODs. After OLT, the value on POD 28 had a strong association with graft function.

Human amniotic stem cells improve hepatic microvascular dysfunction and portal hypertension in cirrhotic rats

BACKGROUND AND AIMS

Portal hypertension is the main consequence of cirrhosis, responsible for the complications defining clinical decompensation. The only cure for decompensated cirrhosis is liver transplantation, but it is a limited resource and opens the possibility of regenerative therapy. We investigated the potential of primary human amniotic membrane-derived mesenchymal stromal (hAMSCs) and epithelial (hAECs) stem cells for the treatment of portal hypertension and decompensated cirrhosis.

METHODS

In vitro: Primary liver sinusoidal endothelial cells (LSECs) and hepatic stellate cells (HSCs) from cirrhotic rats (chronic CCl₄ inhalation) were co-cultured with hAMSCs, hAECs or vehicle for 24 hours, and their RNA profile was analysed. In vivo: CCl₄-cirrhotic rats received 4x10⁶ hAMSCs, 4x10⁶ hAECs, or vehicle (NaCl 0.9%) (intraperitoneal). At 2-weeks we analysed: a) portal pressure (PP) and hepatic microvascular function; b) LSECs and HSCs phenotype; c) hepatic fibrosis and inflammation.

RESULTS

In vitro experiments revealed sinusoidal cell phenotype amelioration when co-cultured with stem cells. Cirrhotic rats receiving stem cells, particularly hAMSCs, had significantly lower PP than vehicle-treated animals, together with improved liver microcirculatory function. This hemodynamic amelioration was associated with improvement in LSECs capillarization and HSCs de-activation, though hepatic collagen was not reduced. Rats that received amnion derived stem cells had markedly reduced hepatic inflammation and oxidative stress. Finally, liver function tests significantly improved in rats receiving hAMSCs.

CONCLUSIONS

This preclinical study shows that infusion of human amniotic stem cells effectively decreases PP by ameliorating liver microcirculation, suggesting that it may represent a new treatment option for advanced cirrhosis with portal hypertension.

How can we optimise antifungal use in a solid organ transplant centre? Local epidemiology and antifungal stewardship implementation: A single-centre study

PURPOSE

We aimed to implement and to assess the impact of the antifungal stewardship programme (AFSp) on prescription appropriateness of antifungals, management and outcomes of candidaemia patients, and antifungal consumption and costs at our solid organ transplant (SOT) institute.

METHODS

Local epidemiology of invasive fungal infections (IFIs) from 2009 to 2017 was analysed in order to prepare an effective AFSp, implemented in January 2018. It included suspension of empirical antifungal prescriptions after 72 hours (antifungal time-out), automated alert and infectious disease (ID) consult for empirical prescriptions and for every patient with IFI, and indication for step-down to oral fluconazole when possible. We used process measures and results measures to assess the effects of the implemented programme.

RESULTS

The ASFp led to significant improvements in selection of the appropriate antifungal (40.5% in pre-AFS vs 78.6% in post-AFS), correct dosing (51.2% vs 79.8%), correct length of treatment (55.9% vs 75%) and better management of patients with candidaemia. Analysis of prescribed empirical antifungal revealed that defined daily doses (DDDs) per 100 patient days decreased by 36.7% in 2018 compared to the average of pre-AFSp period, with important savings in costs.

CONCLUSION

This AFSp led to a better use of antifungal drugs in terms of appropriateness and consumption, with stable clinical and microbiological outcomes in patients with IFI.

Consistency test of coincidence-summing calculation methods for extended sources

An internal consistency test of the calculation of coincidence-summing correction factors F_C for volume sources is presented. The test is based on exact equations relating the values of F_C calculated for three ideal measurement configurations. The test is applied to a number of 33 sets of F_C values sent by 21 teams. Most sets passed the test, but not the results obtained using the quasi-point source approximation; in the latter case the test qualitatively indicated the magnitude of the bias of F_C.

P979Persistent atrial fibrillation terminated within the left atrium without recurrence at follow-up demonstrates a gradual intracardiac organization during stepwise ablation

Introduction

We previously reported that patients (pts) with recurrence (Rec) after stepwise catheter ablation (step-CA) of persistent atrial fibrillation (pAF) exhibit high bi-atrial intracardiac dominant frequencies (DF) values before ablation, indicative of a severe bi-atrial electro-anatomical remodeling.

Purpose

Herein, we hypothesized that a gradual decrease in DF values during step-CA is associated with pAF termination and maintenance of sinus rhythm (SR) on the long term.

Method

In 40 consecutive pts (61±8 yo, sustained AF duration 19±11 months), pulmonary vein isolation (PVI) and left atrium (LA) ablation were performed until pAF termination or cardioversion. 10-sec intracardiac electrograms (EGMs) epochs were recorded before ablation (BL), during PVI and during complex fractionated atrial electrograms (CFAEs) and linear ablation (post_PVI) in the right atrial (RAA) and left atrial (LAA) appendages and in the coronary sinus (CS). DF was defined as the highest peak within the [3–15] Hz EGM spectrum. Rec was defined as any atrial arrhythmia lasting >30 sec during follow-up (FU).

Results

pAF was terminated within the LA in 70% (28/40, LT) of the pts, while 30% (12/40, NLT) were not. After a mean FU of 34±14 months, all NLT pts had a Rec, while LT pts presented a Rec in 71% (20/28, LT_rec) and remained in SR in 29% (8/28, LT_norec). Figure 1 shows: 1) a gradient in DF values measured in the LAA (panel A), RAA (panel B) and CS (panel C) with the highest values in NLT pts (red), intermediate values in LT_rec pts (yellow) and lowest DF values in LT_norec pts (green); 2) all three groups displayed a gradual intracardiac organization during LA ablation as shown by decreasing DF values (p<0.05, BL vs post_PVI), but the LT_norec pts (green) exhibited the highest relative changes in DF from BL (p<0.05, LT_norec vs NLT, Δ range: −5.31 to −9.69%).

Figure 1. Effect of ablation on DF

Conclusion

Low DF values before ablation and gradual intracardiac organization until pAF termination are associated with maintenance of SR on the long term.

A benchmark for Monte Carlo simulation in gamma-ray spectrometry

Monte Carlo (MC) simulation is widely used in gamma-ray spectrometry, however, its implementation is not always easy and can provide erroneous results. The present action provides a benchmark for several MC software for selected cases. The examples are based on simple geometries, two types of germanium detectors and four kinds of sources, to mimic eight typical measurement conditions. The action outputs (input files and efficiency calculation results, including practical recommendations for new users) are made available on a dedicated webpage.

Epidemiology and successful containment of a carbapenem-resistant Enterobacteriaceae outbreak in a Southern Italian Transplant Institute

INTRODUCTION

Carbapenem-resistant enterobacteriaceae (CRE) infections are difficult to treat and pose a serious threat to solid organ transplant (SOT) recipients. At our institute we observed an infection burden in 2012.

METHODS

In order to contain the spread of CRE infections, we established a taskforce to implement guidelines suggested by the Centers for Disease Control and Prevention (CDC) for this type of outbreak. Here, we describe the epidemiology of the outbreak in our SOT population, and the effectiveness of such interventions, by comparing levels of CRE hospital-acquired infection (HAI) pre- and post-task force intervention (from January 2009 to December 2012, and from September 2013 to December 2016, respectively) through a linear regression model.

RESULTS

In this study, we included 933 patients who underwent a total of 1017 SOT procedures, 286 of whom had a CRE-positive culture (28.8%), of which 65 (22.7% of CRE positive) developed infection. One-year mortality post-SOT was significantly higher in patients with CRE infection. After the taskforce intervention, the CRE HAI rate in SOT showed a significant inverse trend (event rate: -1.28, CI -1.70 to 0.86; P < 0.01).

CONCLUSION

In the paucity of treatment options, the application of CDC measures in our SOT institute contributed significantly to containing CRE infections.

Role of Allelic Imbalance in Predicting Hepatocellular Carcinoma (HCC) Recurrence Risk After Liver Transplant

Background

One of the most controversial problems for liver transplantation in patients affected by hepatocellular carcinoma (HCC) remains the lack of an oncologic staging system to predict cancer recurrence after liver transplantation (LT). We analyzed allelic imbalance (AI) in 19 microsatellites, and assessed the post-LT HCC recurrence risk.

Material/Methods

Seventy-one patients were included; 18 had tumor recurrence within 5 years post-transplant. Molecular analysis was done in the primary HCC and peripheral blood samples: a total of 19 microsatellites was used to assess AI. Specific AI was evaluated when outside of range value between 0.66 and 1.5. Based on data in the literature, we grouped the 19 microsatellites into 4 panels. We calculated the fractional allelic imbalance (FAI) to make comparisons between different panels including different subsets of microsatellites.

Results

We report that AI was associated with HCC recurrence in 3 main loci (D3S2303, D9S251, and D9S254). Tumor recurrence was associated only with 2 specific panels with 9 microsatellites previously reported to be associated with high risk for HCC recurrence. Our data show that fractional allelic imbalance (FAI) index has good negative ability to predict HCC recurrence (Panel 2: negative predictive value of 95%).

Conclusions

AI analysis could have prognostic value in risk management of HCC recurrence after LT, especially for early recurrence.

Neurological complications after cardiac surgery: a retrospective case-control study of risk factors and outcome

Background

To evaluate incidence, risk factors, and outcomes of postoperative neurological complications in patients undergoing cardiac surgery.

Methods

A total of 2121 patients underwent cardiac surgery between August, 2008 and December, 2013; 91/2121 (4.3%) underwent brain computed tomography (70/91, 77%) or magnetic resonance imaging (21/91, 23%) scan because of major stroke (37/2121, 1.7%) and a spectrum of transient neurological episodes as well as transient ischemic attacks and delirium /psychosis/seizures (54/2121, 2.5%). The mean age was 65.3 ± 12.1 years and 60 (65.9%) were male. Variables were compared among study- and matched-patients (n = 113) without neurological deficits.

Results

A total of 37/2121 (1.7%) patients had imaging evidence of stroke. Radiological examinations were done 5.72 ± 3.6 days after surgery. Patients with and without imaging evidence of stroke had longer intensive care unit length of stay (LOS) (13.8 ± 14.7 and 12.9 ± 15 days vs. 5.7 ± 12.1 days, respectively (p < 0.001) and hospital LOS (53 ± 72.8 and 35.5 ± 29.8 days vs. 18.4 ± 29.2 days, respectively (p < 0.001) than the control group. The hospital mortality of patients with and without imaging evidence of stroke was higher than the control group (7/37 patients [19%], and 12/54 patients [22%] vs. 4/115 patients [3%], respectively (p < 0.001). Multivariate analysis showed that bilateral internal carotid artery stenosis of any grade (p < .001), and re-do operations (p = .013) increased the risk of postoperative neurological complications.

Conclusions

Neurological complications after cardiac surgery increase hospitalization and mortality even in patients without radiologic evidence of stroke. Bilateral internal carotid artery stenosis of any grade, suggesting a diffuse patient propensity toward atherosclerosis, and re-do operations increase the risk of postoperative neurological complications.

The addition of simvastatin administration to cold storage solution of explanted whole liver grafts for facing ischemia/reperfusion injury in an area with a low rate of deceased donation: a monocentric randomized controlled double-blinded phase 2 study

BACKGROUND

Liver transplantation is the best treatment for end-stage liver disease. The interruption of the blood supply to the donor liver during cold storage damages the liver, affecting how well the liver will function after transplant. The drug Simvastatin may help to protect donor livers against this damage and improve outcomes for transplant recipients. The aim of this study is to evaluate the benefits of treating the donor liver with Simvastatin compared with the standard transplant procedure.

PATIENT AND METHODS

We propose a prospective, double-blinded, randomized phase 2 study of 2 parallel groups of eligible adult patients. We will compare 3-month, 6-month, and 12-month graft survival after LT, in order to identify a significant relation between the two homogenous groups of LT patients. The two groups only differ by the Simvastatin or placebo administration regimen while following the same procedure, with identical surgical instruments, and medical and nursing skilled staff. To reach these goals, we determined that we needed to recruit 106 patients. This sample size achieves 90% power to detect a difference of 14.6% between the two groups survival using a one-sided binomial test.

DISCUSSION

This trial is designed to confirm the effectiveness of Simvastatin to protect healthy and steatotic livers undergoing cold storage and warm reperfusion before transplantation and to evaluate if the addition of Simvastatin translates into improved graft outcomes.

TRIAL REGISTRATION

ISRCTN27083228 .

Guillain-Barré syndrome after orthotopic liver transplantation: A clinical manifestation of immune reconstitution inflammatory syndrome?

Guillain-Barrè Syndrome, as part of the spectrum of dysimmune neuropathies, is unexpected to occur in immunocompromised hosts. We describe a clinical case of Guillain-Barrè syndrome, occurred a few weeks after a liver transplant, and we postulate that our case would satisfy all requirements to explain this peripheral nervous system complication as a clinical manifestation of an Immune reconstitution inflammatory syndrome. In this setting of liver transplantation, complicated by potentially multiple infective triggers, reduction of immunosuppression and reversal of pathogen-induced immunosuppression, through antimicrobial therapy, may have led to pro-inflammatory response. The pro-inflammatory pattern would have sustained the pathophysiologic mechanism of this immune neuropathy.

Lung resident mesenchymal cells isolated from patients with the Bronchiolitis Obliterans Syndrome display a deregulated epigenetic profile

Bronchiolitis Obliterans Syndrome is the major determinant of the graft function loss after lung transplantation, but its pathogenesis is still incompletely understood and currently available therapeutic strategies are poorly effective. A deeper understanding of its pathogenic mechanisms is crucial for the development of new strategies to prevent and treat this devastating complication. In this study, we focused on the mesenchymal stromal cells, recently recognized as BOS key effectors, and our primary aim was to identify their epigenetic determinants, such as histone modifications and non-coding RNA regulation, which could contribute to their differentiation in myofibroblasts. Interestingly, we identified a deregulated expression of histone deacetylases and methyltransferases, and a microRNA-epigenetic regulatory network, which could represent novel targets for anti-fibrotic therapy. We validated our results in vitro, in a cell model of fibrogenesis, confirming the epigenetic involvement in this process and paving the way for a new application for epigenetic drugs.

Blink reflex recovery cycle to differentiate progressive supranuclear palsy from corticobasal syndrome

BACKGROUND AND PURPOSE

Progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) may share similar clinical findings and tests to distinguish between the two disorders could be useful. We evaluated the blink reflex and R2 blink reflex recovery cycle (R2BRRC), determining diagnostic sensitivity, specificity and positive and negative predictive value of R2BRRC in differentiating patients with PSP from those with CBS.

METHODS

This was a prospective data collection study investigating blink reflex and R2BRRC at interstimulus intervals (ISIs) of 100, 150, 200, 300, 400, 500 and 750 ms in 12 patients with PSP, eight patients with CBS and 10 controls.

RESULTS

Patients with PSP have earlier recruitment of R2BRRC as compared with patients with CBS (ISI: 100 ms, P = 0.002; 150 ms, P < 0.001; 200 ms, P < 0.001; 300 ms, P = 0.02) and controls (ISI: 100 ms, P < 0.001; 150 ms, P < 0.001; 200 ms, P < 0.001; 300 ms, P = 0.004). The presence of an early recovery of the R2 differentiated PSP from CBS with a specificity and sensitivity of 87.5% and 91.7%, respectively.

CONCLUSIONS

The R2BRRC curve might be considered to be a useful tool in differentiating patients with PSP from those with CBS.

Results of an international comparison of activity measurements of 68Ge

An international key comparison, identifier CCRI(II)-K2.Ge-68, has been performed. The National Institute of Standards and Technology (NIST) served as the pilot laboratory, distributing aliquots of a 68Ge/68Ga solution. Results for the activity concentration, CA, of 68Ge at a reference date of 12h00 UTC 14 November 2014 were submitted by 17 laboratories, encompassing many variants of coincidence methods and liquid-scintillation counting methods. The first use of 4π(Cherenkov)β-γ coincidence and anticoincidence methods in an international comparison is reported. One participant reported results by secondary methods only. Two results, both utilizing pure liquid-scintillation methods, were identified as outliers. Evaluation using the Power-Moderated Mean method results in a proposed Comparison Reference Value (CRV) of 621.7(11)kBqg-1, based on 14 results. The degrees of equivalence and their associated uncertainties are evaluated for each participant. Several participants submitted 3.6mL ampoules to the BIPM to link the comparison to the International Reference System (SIR) which may lead to the evaluation of a Key Comparison Reference Value and associated degrees of equivalence.

Radiation Doses to Operators in Hepatobiliary Interventional Procedures

PURPOSE

The primary aim of this study is to provide a summary of operators' radiation doses during hepatobiliary fluoroscopic guided procedures. In addition, patient dose in these procedures was also documented.

MATERIALS AND METHODS

A total of 283 transarterial chemoembolisation (TACE) and 302 biliary procedures, including 52 percutaneous transhepatic cholangiogram (PTC), 36 bilioplasty and 214 biliary catheter changes (BCC) performed over 14 months, were included. Electronic personal dosimeters were used to measure operator radiation doses. Effective dose (E) was calculated using modified Niklason algorithm. Patient dose was measured as dose area product (DAP) and fluoroscopy time (FT).

RESULTS

For TACE, E for radiologist ranged between 0 and 9.96 µSv, for radiographer 0-0.99 µSv and for nurse 0-4.65 µSv. The patient DAP and FT ranged between 1.5 and 421.9 Gy cm² and 1.91-67.25 min. For PTC, E for the radiologist ranged between 0.33 and 55.89 µSv, for radiographer 0-38.61 µSv and for nurse 0-3.18 µSv. Patient DAP and FT ranged between 1.7 and 218.4 Gy cm² and 2.07-71.53 min. For bilioplasty, E ranged between 0.09 and 9.24 µSv for radiologist, 0-0.84 µSv for radiographer and 0-1.38 µSv for nurse. The patients' DAP and FT ranged from 0.7 to 52.54 Gy cm² and 1.13-24.47 min. For BCC, E ranged from 0 to 12.78 µSv for radiologist, 0-8.43 µSv for radiographer and 0-4.05 µSv for nurse. Patient DAP and FT ranged between 0.12 and 117.3 Gy cm² and 0.57-15.83 min.

CONCLUSIONS

This study shows that doses to all operators performing hepatobiliary interventional procedures can be very low.

Successful Treatment of Kaposi Sarcoma-Associated Herpesvirus Inflammatory Cytokine Syndrome After Kidney-Liver Transplant: Correlations With the Human Herpesvirus 8 miRNome and Specific T Cell Response

After transplant, patient infection with human herpesvirus 8 (HHV-8) and Kaposi sarcoma-associated herpesvirus (KSHV) is known to cause aggressive tumors and severe nonneoplastic complications. These latter syndromes are driven by HHV-8/KSHV lytic reactivations and related hyperinflammatory host responses typically characterized by high viral loads, elevated levels of cytokines and other inflammation biomarkers, cytopenia, organ failure, high fever, and worsening conditions (with no evidence of B cell neoplasias). These disorders are associated with a high mortality rate, often due to lack of prompt diagnosis, effective therapeutic approaches, and adequate follow-up. These features resemble most of those defining the so-called KSHV-associated inflammatory cytokine syndrome (KICS), which was recently recognized in patients positive for human immunodeficiency virus (HIV). In this report, we describe-for the first time-a case of a KICS-like nonneoplastic recurrent complication occurring after transplant in an HIV-negative patient that was successfully treated by a combination of anti-CD20 monoclonal therapy, antivirals, and modification of the immunosuppressive regimen. In addition to clinical and laboratory findings collected during 3-year follow-up, we report novel experimental data on HHV-8-specific T cell dynamics and circulating microRNA profile, showing correlations with clinical course and other laboratory markers (including viral load, C-reactive protein, and cytokine levels), providing useful information about abnormal cellular and cytokine dynamics underlying HHV-8-associated inflammatory disorders in posttransplant patients.

Use of Hepatitis C-Positive Deceased Liver Donors in Response to the Organ Shortage in an Endemic Area

The region of Sicily, Italy, is witnessing a chronic organ shortage. Thus, to face this critical issue, the use of marginal donors has increased over time. An example of marginal donor expansion is the use of liver donors who are positive for the hepatitis C antibody (HCV+) for HCV+ patients requiring liver transplantation (LT). In view of new advances in HCV therapy, including direct-acting agents (DAAs) to treat HCV in the post-transplant setting, our study focused on a monocentric experience in a series of consecutive LTs performed in adult patients receiving HCV+ liver donor allografts. From 2003 to 2016 at our institute we performed 10 LT using HCV+ deceased donors. In particular, the pre-LT histological examination in 1 case showed a framework of moderate steatosis (35% microvesicular and 10% macrovesicular) with micro/macrovesicular steatosis <10% in all the other cases. A fibrous framework of 1/6 according to the Ishak score in a single case, and 2/6 in 2 cases, were highlighted, while there was no fibrosis in the other 7 cases. A picture of periportal inflammation was still detected in 4 cases, with no evidence of inflammatory lesions in the remaining cases. The patient survival was 100% at 1 and 3 years, and 85.7% at 5 years post-LT. One-, three- and five-year graft survivals were 100.0%, 88.9%, and 71.4%, respectively. Only 1 patient underwent re-LT after 2 years, because of chronic rejection. Based on our experience using HCV+ deceased liver donors with a moderate degree of fibrosis, we believe that accepting marginal donors is a feasible therapeutic option when facing a liver donor shortage.

Response of Human Fetal Liver Progenitor Cell Types to Temperature and pH Stresses In Vitro

Prolonged physiological stresses, including abnormal pH and temperature, are deleterious. However, human hepatic progenitors have been shown to be quite tolerant of temporary temperature stress such as in cold ischemia. We aimed at identifying how various stresses affect liver progenitors, and at determining whether distinct effects exist on different progenitor cells of the human liver. Total fetal liver cells were exposed to low (25°C), normal (37°C), or high (40°C) temperatures, or low (6.76), normal (7.35), or high (7.88) pH in vitro. Culture at 25°C increased cell numbers and percentages of proliferation marker Ki67⁺ total cells. In total cell cultures, percentages of CD326⁺ hepatic progenitors co-expressing DLK1 (delta-like 1 homolog), SSEA4, or CD90 increased, as well as proliferation of SSEA4⁺ and CD235a⁺ progenitors. Analyses of presorted hepatic progenitors revealed that culture at 25°C increased cell numbers of CD326⁺ hepatic stem/progenitor cells but not DLK⁺ hepatoblasts. The expression of several mesenchymal genes was reduced, and distinct hepatic stem/progenitor cell colonies emerged. At 40°C, numbers of adherent hepatic cells decreased but those of hematopoietic nonadherent cells increased. High pH did not cause major effects. Acidic pH resulted in decreased total cell numbers and affected hematopoietic cells. Percentages of DLK1⁺ hepatoblasts were increased, but those of hematopoietic mature CD45⁺ cells were decreased. In particular, proliferation of adherent hepatic CD326⁺, SSEA4⁺ progenitors, and hematopoietic CD45⁺ cells and CD235a⁺ erythroblasts was reduced. Conclusively, our data indicate that low-temperature stress stimulates hepatic progenitor and erythroblast proliferation, whereas acidic pH promotes hepatic maturation and reduces hematopoietic cells.

Systematic influences on the areas of peaks in gamma-ray spectra that have a large statistical uncertainty

A method is presented for calculating the expected number of counts in peaks that have a large relative peak-area uncertainty and appear in measured gamma-ray spectra. The method was applied to calculations of the correction factors for peaks occurring in the spectra of radon daughters. It was shown that the factors used for correcting the calculated peak areas to their expected values decrease with an increasing relative peak-area uncertainty. The accuracy of taking the systematic influence inducing the correction factors into account is given by the dispersion of the correction factors corresponding to specific peaks. It was shown that the highest accuracy is obtained in the peak analyses with the GammaVision and Gamma-W software.