Development of a machine learning model for the prediction of the short-term mortality in patients in the intensive care unit.

PURPOSE: The aim of this study was to develop and evaluate a machine learning model that predicts short-term mortality in the intensive care unit using the trends of four easy-to-collect vital signs. MATERIALS AND METHODS: The primary training cohort included 1968 patients at the Veterans Health Service Medical Center. The external validation cohort comprised 409 patients at Seoul National University Hospital. Datasets of heart rate, systolic blood pressure, diastolic blood pressure, and peripheral capillary oxygen saturation (SpO2) measured every hour for 10 h were used. The performances of mortality prediction models generated using five machine learning algorithms, Random Forest (RF), XGboost, perceptron, convolutional neural network, and Long Short-Term Memory, were calculated and compared using area under the receiver operating characteristic curve (AUROC) values and an external validation dataset. RESULTS: The machine learning model generated using the RF algorithm showed the best performance. Its AUROC was 0.922, which is much better than the 0.8408 of the Acute Physiology and Chronic Health Evaluation II. The machine learning model developed using SpO2 showed the best performance (AUROC, 0.89). CONCLUSIONS: This simple yet powerful new mortality prediction model could be useful for early detection of probable mortality and appropriate medical intervention, especially in rapidly deteriorating patients.

A case with acute-on-chronic liver failure receiving liver transplantation during daclatasvir and asunaprevir therapy in chronic hepatitis C patient.

We report a case with hepatitis C virus genotype 1 b liver cirrhosis who received liver transplantation because of acute-on-chronic liver failure during daclatasvir (DSV) and asunaprevir (ASV) combination therapy. To our knowledge, this is the first case received liver transplantation during DSV + ASV therapy. Therefore, clinicians should pay particular attention to the possibility of acute liver failure during DSV and ASV combination therapy.

An Enhanced Soft Vibrotactile Actuator Based on ePVC Gel with Silicon Dioxide Nanoparticles.

In this paper, we propose a soft vibrotactile actuator made by mixing silicon dioxide nanoparticles and plasticized PVC gel. The effect of the silicon dioxide nanoparticles in the plasticized PVC gel for the haptic performance is investigated in terms of electric, dielectric, and mechanical properties. Furthermore, eight soft vibrotactile actuators are prepared as a function of the content. Experiments are conducted to examine the haptic performance of the prepared eight soft vibrotactile actuators and to find the best weight ratio of the plasticized PVC gel to the nanoparticles. The experiments should show that the plasticized PVC gel with silicon dioxide nanoparticles improves the haptic performance of the plasticized PVC gel-based vibrotactile actuator, and the proposed vibrotactile actuator can create a variety of haptic sensations in a wide frequency range.

Crack-Enhanced Microfluidic Stretchable E-Skin Sensor.

We reported the development of a transparent stretchable crack-enhanced microfluidic capacitive sensor array for use in E-skin applications. The microfluidic sensor was fabricated through a simple lamination process involving two silver nanowire (AgNW)-embedded rubbery microfluidic channels arranged in a crisscross fashion. The sensing performance was optimized by testing a variety of sensing liquids injected into the channels. External mechanical stimuli applied to the sensor induced the liquid to penetrate the deformed microcracks on the rubber channel surface. The increased interfacial contact area between the liquid and the nanowire electrodes increased the capacitance of the sensor. The device sensitivity was strongly related to both the initial fluid interface between the liquid and crack wall and the change in the contact length of the liquid and crack wall, which were simulated using the finite element method. The microfluidic sensor was shown to detect a wide range of pressures, 0.1-140 kPa. Ordinary human motions, including substantial as well as slight muscle movements, could be successively detected, and 2D color mappings of simultaneous external load sensing were collected. Our simple method of fabricating the microfluidic channels and the application of these channels to stretchable e-skin sensors offers an excellent sensing platform that is highly compatible with emerging medical and electronic applications.

Recurrences of hepatocellular carcinoma following complete remission by transarterial chemoembolization or radiofrequency therapy: Focused on the recurrence patterns.

AIM: In this study, we analyzed the rates and patterns of recurrences in hepatocellular carcinoma (HCC) patients who had achieved complete remission (CR) by transarterial chemoembolization (TACE) or radiofrequency ablation (RFA), and also examined the differences of recurrence patterns between TACE-treated and RFA-treated groups. METHODS: We followed 309 consecutive HCC patients who achieved CR following TACE (n = 220) or RFA (n = 89) for a median of 68 months. Recurrence patterns were classified as local recurrence and secondary tumor according to location of recurrence (≤2 cm and >2 cm from primary tumor). RESULTS: Recurred HCC had been found in 231 out of 309 patients (75%) with CR by TACE or RFA; 112 local recurrences (48%), 100 secondary tumor (43%) and 19 both (9%). The cumulative recurrence rates at 1, 3 and 5 years were 22%, 64% and 79%, respectively. The overall recurrences at 1, 3 and 5 years following CR in the TACE-treated group was not different from those in the RFA-treated group (21%, 68% and 81% vs 26%, 56% and 84%, respectively; P = NS) However, the cumulative occurrence rates of local recurrence rates at 1, 3 and 5 years were significantly higher in the TACE-treated group compared to the RFA-treated group (15%, 53% and 65% vs 15%, 27% and 34%, respectively; P = 0.001). CONCLUSION: Recurrence of HCC is very common, even following CR by TACE or RFA. Especially, local recurrences are very frequent in cases who achieved CR by TACE, which suggests that additional ablation therapy may be beneficial to prevent recurrences following CR by TACE.

Predisposing factors of hepatocellular carcinoma recurrence following complete remission in response to transarterial chemoembolization.

BACKGROUND AND AIM: The aim of our study was to determine the predictors of recurrences in hepatocellular carcinoma (HCC) patients who had achieved complete remission (CR) by transarterial chemoembolization (TACE). METHODS: A total of 220 consecutive HCC patients who had achieved CR by TACE were followed for a median 72 months. CR was defined as complete lipiodol uptake based on the results of lipiodol-computed tomography 4 weeks after TACE and no additional tumor staining on the follow-up angiography. Recurrence patterns were classified as local recurrence and secondary tumor, respectively, in relation to the location of recurrence; early and late recurrence were classified in relation to recurrence time. RESULTS: Recurrence of HCC was observed in 169 patients (77 %), of whom 91 (54 %) had local recurrences, 61 (36 %) had secondary tumor, and 17 (10 %) had both. There were 45 (27 %) early and 124 (73 %) late recurrences. Local recurrence developed more frequently in patients with early recurrence than in those with late recurrence (62 vs. 51 %, respectively), while secondary tumor was detected more commonly in patients with late recurrence than in those with early recurrence (39 vs. 29 %, respectively; P < 0.001). In multivariate analyses, multinodularity [hazard ratio (HR) 2.351, P = 0.023] and a persistently high serum alpha-fetoprotein level following CR (HR 3.173, P < 0.001) were significant predictors of early recurrence. Older age (≥ 60 years; HR 1.531, P = 0.043), advanced Child-Pugh class (HR 1.983, P = 0.002), and the association with cirrhosis (HR 1.756, P = 0.028) were predictors of late recurrence following CR. CONCLUSIONS: Early recurrences following CR by TACE may be due mainly to undetectable remaining tumors, whereas late recurrences may be caused by newly appearing tumors in patients with a background of advanced cirrhotic liver.

Optimal measurement modality and method for evaluation of responses to transarterial chemoembolization of hepatocellular carcinoma based on enhancement criteria.

PURPOSE: To determine the usefulness of enhancement by iodized oil deposits on computed tomography (CT) following transarterial chemoembolization for hepatocellular carcinoma (HCC), and to compare the reliability of such CT imaging with that of magnetic resonance (MR) imaging. MATERIALS AND METHODS: Fifty-one patients for whom resected or explanted livers containing chemoembolized HCC lesions of at least 1 cm were available. Imaging responses were determined based on modified Response Evaluation Criteria In Solid Tumors (mRECIST) and European Association for the Study of the Liver (EASL) criteria for 59 target tumors on CT and MR scans before surgery. CT-based evaluation was performed per mRECIST and EASL criteria, considering iodized oil retention as indicating necrosis and, alternatively, as enhancing viable tissue ("mRECIST-Lipiodol" and "EASL-Lipiodol"). Pathologic necrosis was graded as 100%, 50%-99%, or less than 50%. RESULTS: Goodman-Kruskal γ-values for radiologic-pathologic correlation were greater than 0.95 for mRECIST and EASL criteria on CT or MR imaging. However, mRECIST-Lipiodol and EASL-Lipiodol measurements showed weaker correlation with pathologic findings, with γ-values of 0.797 and 0.846, respectively. With respect to intermethod agreement, weighted γ-values for mRECIST by CT and MR, and for EASL criteria by CT and MR, both exceeded 0.80, whereas mRECIST-Lipiodol and EASL-Lipiodol showed only moderate levels of agreement with mRECIST/EASL criteria by CT or MR imaging, with γ-values of 0.522-0.631. CONCLUSIONS: Response estimation based on measurement of iodized oil deposits as necrosis on CT when applying enhancement criteria after chemoembolization for HCC correlated well with actual pathologic class, and agreed with MR-based evaluation.

Clinical utility of des-γ-carboxyprothrombin kinetics as a complement to radiologic response in patients with hepatocellular carcinoma undergoing transarterial chemoembolization.

PURPOSE: Serial α-fetoprotein (AFP) measurements are useful for assessing tumor responses to numerous therapies for hepatocellular carcinoma (HCC). This study tested the predictive value of changes in des-γ-carboxy prothrombin (DCP), in parallel with AFP, as an indicator of HCC response after transarterial chemoembolization. MATERIALS AND METHODS: The study group consisted of 327 patients with HCC initially seropositive for DCP (≥ 40 mAU/mL) and/or AFP (≥ 100 ng/mL) who underwent repeated chemoembolization as first-line therapy. Radiologic responses were measured based on modified Response Evaluation Criteria In Solid Tumors guidelines. Serologic response was defined as a decrease of at least 50% in DCP or AFP level from baseline. Radiologic-serologic correlation and disease progression and survival according to serologic responses were analyzed. RESULTS: Before treatment, 129 patients (39%) had high DCP alone, 66 (20%) had high AFP alone, and 58 (18%) had high levels of both. Radiologic and serologic responses were achieved in 88.2% and 91.4% of patients with high DCP levels and in 89.5% and 91.1% of those with high AFP levels, respectively. Serologic response based on AFP or DCP was significantly correlated with radiologic response, and this was confirmed by landmark analysis (P < .001). DCP and AFP responders had better times to progression and overall survival than nonresponders (P < .001). Cox models revealed that both serologic responses were independent estimates of survival (hazard ratios, 0.11 for DCP and 0.14 for AFP; P < .001). CONCLUSIONS: After transarterial chemoembolization for HCC, DCP response may be a useful surrogate endpoint of immediate and prolonged clinical outcomes, along with AFP response.