Development of a Machine Learning Model to Estimate the Biotic Ligand Model-Based Predicted No-Effect Concentrations for Copper in Freshwater.

The copper (Cu) biotic ligand model (BLM) has been used for ecological risk assessment by taking into account the bioavailability of Cu in freshwater. The Cu BLM requires data for many water chemistry variables, such as pH, major cations, and dissolved organic carbon, which can be difficult to obtain from water quality monitoring programs. To develop an optimized predicted no-effect concentration (PNEC) estimation model based on an available monitoring dataset, we proposed an initial model that considers all BLM variables, a second model that requires variables excluding alkalinity, and a third model using electrical conductivity as a surrogate for the major cations and alkalinity. Furthermore, deep neural network (DNN) models have been used to predict the nonlinear relationships between the PNEC (outcome variable) and the required input variables (explanatory variables). The predictive capacity of DNN models was compared with the results of other existing PNEC estimation tools using a look-up table and multiple linear and multivariate polynomial regression methods. Three DNN models, using different input variables, provided better predictions of the Cu PNECs compared with the existing tools for the following four test datasets: Korean, United States, Swedish, and Belgian freshwaters. Consequently, it is expected that Cu BLM-based risk assessment can be applied to various monitoring datasets, and that the most applicable model among the three different types of DNN models could be selected according to data availability for a given monitoring database. Environ Toxicol Chem 2023;42:2271-2283. © 2023 SETAC.

Utility of ultrasound evaluation of I-Gel® placement in children: An observational study.

BACKGROUND: Ultrasound is not widely used to evaluate optimal supraglottic airway positioning even though it could potentially be used to identify and correct problem areas. AIMS: We evaluated a new ultrasound scoring method to identify the position of the supraglottic airway and detect the location of air leaks during ventilation in pediatric patients. METHODS: Using a prospective observational study design, we enrolled 90 pediatric patients of ASA physical status I-III scheduled for elective surgery under general anesthesia. After anesthesia induction, patients were assigned to a noncorrection group or a correction group after their first ultrasound evaluation. Noncorrection group comprised patients with tolerable I-Gel positioning based on ultrasound evaluation and no problems with clinical parameters, while the correction group comprised patients with I-Gel mispositioning based on ultrasound. RESULTS: After the first ultrasound evaluation, 61 patients did not need I-Gel correction (noncorrection group), while 29 patients needed I-Gel correction (correction group) and underwent a second ultrasound evaluation. Airway sealing pressure and total ultrasound score showed a negative correlation (r = -.845, p < .001). The area under the receiver operating curve for total ultrasound score was 0.97 (95% confidence interval, 0.94-0.99; p < .001). In the correction group, ultrasound score and ventilation parameters improved after correction based on ultrasound evaluation. CONCLUSIONS: Ultrasound scores were negatively correlated with airway sealing pressure in pediatric patients. Ultrasound evaluation is useful for detecting misplacement of the I-Gel and can be a useful tool for correction.

The frequency of gastroesophageal reflux when radiofrequency catheter ablation procedures for atrial fibrillation under general anesthesia with a supraglottic device: Observational pilot study.

ABSTRACT: Gastroesophageal reflux (GER) in radiofrequency catheter ablation (RFCA) occurs due to vagal plexus damage during pulmonary vein isolation. We hypothesized that the frequency of GER in the oropharynx will be less compared to other areas (low-esophagus, mid-esophagus). We confirmed the frequency of GER before and after RFCA in 3 areas.We studied 30 patients who were scheduled for RFCA under general anesthesia. Anesthesia was performed using supraglottic devices (SGD) with a suction port. Two esophageal temperature probes capable of suction and measuring temperature were inserted through the suction port. The pH of the 3 areas was measured before and after the RFCA at 3 areas (mid-esophagus, low-esophagus, and oropharynx).GER was observed in 13 of 30 patients (43%). In one patient, it was observed in the oropharynx, in 4 patients it was observed in the mid-esophagus, and in 13 patients, it was observed in the low-esophagus. For patients with GER at the oropharynx and mid-esophagus, it was also observed at the low-esophagus. The difference in the pH before and after the RFCA was not significant at the oropharynx and mid-esophagus (P = .726 and P = .424, respectively), but it was significantly different at the low-esophagus (P < .001). The total ablation time was longer in the GER group compared to the non-GER group (P = .021).GER after RFCA occurred in 43% of patients, only 1 patient in the oropharynx. And aspiration pneumonia after SGD extubation did not occur. Therefore, the use of SGDs in RFCA does not completely eliminate the possibility of aspiration, so care should be taken.

The association of serum lipids with renal function: the Korea Medical Institute Study.

BACKGROUND: Both serum lipids and renal dysfunction are well-known risk factors for cardiovascular diseases. Little data are, however, available on the relation of serum lipids and glomerular filteration rates (GFRs) with low levels of serum cholesterol in Asian populations. METHODS: We performed a large cross-sectional study of 93 228 Korean men and women enrolled in the Korea Medical Institute Study. Serum creatinine was used to estimate the GFR through the simplified modification of diet in renal disease equation. RESULTS: In multivariate logistic regression analysis, those in the highest quartiles of all the lipid biomarkers showed significant associations with the risk of having a GFR of less than 60 ml/min per 1.73 m, compared with those in the lowest quartiles except high-density lipoprotein (HDL) in women. In men, odds ratios (ORs) by triglycerides (TGs) [OR: 1.99; 95% confidence interval (CI): 1.65-2.40], and TG/HDL (OR: 1.98; 95% CI: 1.64-2.38) were higher than others. In women, low-density lipoprotein (OR: 1.91; 95% CI: 1.42-2.56) and non-HDL (OR: 1.84; 95% CI: 1.35-2.50) showed the highest ORs. These associations were stronger among male participants with diabetes; total cholesterol (OR: 2.03; 95% CI: 1.04-3.96), TG (OR: 18.08; 95% CI: 2.46-133.13) and TG/HDL (OR: 17.97; 95% CI: 2.44-132.30), respectively. CONCLUSION: We conclude that potentially modifiable lipid biomarkers are elevated in the setting of less than 90 ml/min per 1.73 m of GFR and there will be the link between renal insufficiency and the increased risk for cardiovascular events in the Korean population.