Machine learning based quantitative pain assessment for the perioperative period.

This study developed and evaluated a model for assessing pain during the surgical period using photoplethysmogram data from 242 patients. Pain levels were measured at 2 min intervals using a numerical rating scale or clinical criteria: preoperative, before and after intubation, before and after skin incision, and postoperative. Key features from the photoplethysmography waveform were extracted to build XGBoost-based models for intraoperative and postoperative pain assessment.

A single-centre randomised controlled trial comparing the standard method and target-controlled infusion as a method of administering cefoxitin, which is used to prevent surgical site infections in colorectal surgical patients: study protocol.

Background: Prophylactic parenteral administration of antibiotics is strongly recommended to prevent surgical site infection (SSI). Cefoxitin is mainly administered intravenously in colorectal surgery. The current standard method for administering prophylactic antibiotics in adults is to administer a fixed dose quickly before skin incision.

Performance evaluation of non-invasive cardiac output monitoring device (HemoVista) based on multi-channel thoracic impedance plethysmography technology.

Background: A non-invasive method of measuring cardiac output (CO) can be beneficial in the care of critically ill patients. HemoVista (BiLab Co., Ltd.

Dosing Strategy of Ramosetron to Prevent Postoperative Nausea and Vomiting and Development of Prediction Models Using Data Obtained From Randomized Controlled Trials: A Comparative Study.

Purpose: The study aimed to compare the postoperative nausea and vomiting (PONV) preventive effect of repeated administration of ramosetron with the standard treatment group and compare models to predict the incidence of PONV using machine-learning techniques.

Methods: A total of 261 patients scheduled for breast surgery were analyzed to evaluate the effectiveness of repeated intravenous administration of ramosetron. All patients were administered 0.

Electroencephalographic Features of Elderly Patients during Anesthesia Induction with Remimazolam: A Substudy of a Randomized Controlled Trial.

Background: Although remimazolam is used as a general anesthetic in elderly patients due to its hemodynamic stability, the electroencephalogram characteristics of remimazolam are not well known. The purpose of this study was to identify the electroencephalographic features of remimazolam-induced unconsciousness in elderly patients and compare them with propofol.

Methods: Remimazolam (n = 26) or propofol (n = 26) were randomly administered for anesthesia induction in surgical patients.

Assessment of explicit and implicit memories during remimazolam anaesthesia using the process dissociation procedure: A prospective cohort study.

Background: Memory formation during remimazolam anaesthesia, where a bispectral index (BIS) is sometimes not maintained at less than 60 despite the maximal dose, is worthy of evaluation.

Objective: Investigate the formation of explicit and implicit memories using the process dissociation procedure during remimazolam anaesthesia at a BIS of 60 to 80.

Design: A prospective cohort study.

Frequency and characteristics of patients with bispectral index values of 60 or higher during the induction and maintenance of general anesthesia with remimazolam.

In Korea, the approved anesthetic regimen of remimazolam starts with 6 mg/kg/h or 12 mg/kg/h until loss of consciousness, followed by maintenance at 1-2 mg/kg/h. Some patients receiving remimazolam for general anesthesia experience occasional difficulty maintaining bispectral index (BIS) value ˂ 60. This retrospective study aimed to analyze the data from patients undergoing elective surgery under remimazolam based-general anesthesia to determine the frequency and physical characteristics of patients with BIS values ˂ 60.

Pharmacokinetics of dexmedetomidine in pediatric patients undergoing cardiac surgery with cardiopulmonary bypass.

Background: Cardiopulmonary bypass can affect the pharmacokinetics of anesthetic agents.

Aims: We aimed to evaluate the pharmacokinetics of dexmedetomidine for infants and small children undergoing cardiac surgery with cardiopulmonary bypass based on population pharmacokinetics.

Methods: We enrolled 30 pediatric cardiac surgical patients in this study.

Population pharmacokinetic and pharmacodynamic model of propofol externally validated in Korean elderly subjects.

The Eleveld propofol pharmacokinetic (PK) model, which was developed based on a broad range of populations, showed greater bias (- 27%) in elderly subjects in a previous validation study conducted by Vellinga and colleagues. We aimed to develop and externally validate a new PK-pharmacodynamic (PK-PD) model of propofol for elderly subjects. A population PK-PD model was constructed using propofol plasma concentrations and bispectral index (BIS) values that were obtained from 31 subjects aged 65 years older in previously published phase I studies.

Effect-site concentration of remimazolam at loss and recovery of responsiveness during general anesthesia: a simulation study.

Background: The objective of this study was to investigate the effect-site concentration (Ce) of remimazolam at loss of response (LOR) and recovery of response (ROR) in patients underwent general anesthesia using simulation. In addition, the relationships between patient's factors and simulated Ce at LOR and ROR were examined.

Methods: The medical records of 81 patients who underwent elective surgery under general anesthesia using remimazolam with simulation of Ce between August 4, 2021 and October 12, 2021, were retrospectively reviewed.

Photoplethysmogram based vascular aging assessment using the deep convolutional neural network.

Arterial stiffness due to vascular aging is a major indicator during the assessment of cardiovascular risk. In this study, we propose a method for age estimation by applying deep learning to a photoplethysmogram (PPG) for the non-invasive assessment of the vascular age. The proposed deep learning-based age estimation model consists of three convolutional layers and two fully connected layers, and was developed as an explainable artificial intelligence model with Grad-Cam to explain the contribution of the PPG waveform characteristic to vascular age estimation.

Predictive performance of pharmacokinetic models for target concentration-controlled infusion of cefoxitin as a prophylactic antibiotic in patients with colorectal surgery.

We aimed to evaluate the predictive performance of previously constructed free (C ) and total (C ) cefoxitin pharmacokinetic models and the possibility of administering cefoxitin via the target-controlled infusion (TCI) method in clinical practice. Two external validation studies (N = 31 for C model, N = 30 for C model) were conducted sequentially. Cefoxitin (2 g) was dissolved in 50 mL of normal saline to give a concentration of 40 mg mL .

Novel temperature-responsive hydrogel injected to the incision site for postoperative pain relief in laparoscopic abdominal surgery: a single-blind, randomized, pivotal clinical trial.

Background: A temperature-responsive hydrogel (PF-72; TGel Bio, Inc., Ltd, Seoul, Korea), developed as a sustained drug delivery device, can be mixed with ropivacaine to reduce pain in the incision area. The hydrogel is soluble at low temperatures (2-8 °C) and is converted into a gel at high temperatures (> 30 °C).

The expected advantage of administering prophylactic antibiotics using target- concentration controlled infusion: Development of a new pharmacokinetic model of cefazolin.

The aim of this study was to explore the utility of target-concentration controlled infusion (TCI) as a prophylactic antibiotic administration method based on the results of a population pharmacokinetic model of cefazolin. In patients undergoing elective gastric surgery, 2 g of cefazolin was dissolved in 50 mL of saline and administered for 10 min prior to skin incision. Arterial blood samples were obtained at preset intervals to measure the total and free plasma concentrations of cefazolin.

Development of a new pharmacokinetic model for target-concentration controlled infusion of vancomycin in critically ill patients.

The aim of this prospective study was to construct a new pharmacokinetic model of vancomycin for target-concentration controlled infusion (TCI). As the first loading dose, 25 mg/kg of vancomycin was administered during 60-90 min. Arterial blood samples were obtained at pre-set intervals to measure the serum concentrations of vancomycin.

Development of a new pharmacokinetic model for target-concentration controlled infusion of cefoxitin as a prophylactic antibiotic in colorectal surgical patients.

Aims: There are several limitations to the existing method of administering cefoxitin as a prophylactic antibiotic, and the limitations may be overcome by applying the target-concentration controlled infusion (TCI) method. Population pharmacokinetic parameters are required to administer cefoxitin by the TCI method. The aim of this study was to construct a new pharmacokinetic model of cefoxitin for the TCI method in colorectal surgical patients.

Performance of the Surgical Pleth Index and Analgesia Nociception Index in Healthy Volunteers and Parturients.

Various commercially available nociception devices have been developed to quantify intraoperative pain. The Surgical Pleth Index (SPI) and Analgesia Nociception Index (ANI) are among the analgesic indices that have been widely used for the evaluation of surgical patients. This study aimed to evaluate the clinical performance of the SPI and ANI in conscious healthy volunteers and parturients.

Population pharmacokinetic analysis of ropivacaine extended-release from a temperature-responsive hydrogel in rats.

Therapeutic agents with a short half-life need to be administered frequently to achieve sustained and effective concentrations. This could be accomplished using sustained drug delivery technology. PF-72 (TGel Bio, Inc.

Interpretation of volume kinetics in terms of pharmacokinetic principles.

Volume kinetics is the pharmacokinetics of infusion fluids and describes the distribution and elimination of infused volume. Generally, pharmacokinetic parameters can be estimated by measuring the concentration of a drug. However, it is almost impossible to directly measure the concentration of fluids.

Novel Analgesic Index for Postoperative Pain Assessment Based on a Photoplethysmographic Spectrogram and Convolutional Neural Network: Observational Study.

Background: Although commercially available analgesic indices based on biosignal processing have been used to quantify nociception during general anesthesia, their performance is low in conscious patients. Therefore, there is a need to develop a new analgesic index with improved performance to quantify postoperative pain in conscious patients.

Objective: This study aimed to develop a new analgesic index using photoplethysmogram (PPG) spectrograms and a convolutional neural network (CNN) to objectively assess pain in conscious patients.

Do epoch lengths of hypnotic depth indicators affect estimated of blood-brain equilibration rate constants of propofol?

This study aimed to investigate the effect of epoch length of hypnotic depth indicators on the blood-brain equilibration rate constant (k) estimates of propofol. Propofol was administered by zero-order infusion (1.5, 3.

Performance of the MP570T pulse oximeter in volunteers participating in the controlled desaturation study: a comparison of seven probes.

Background: The performance of the pulse oximeter was evaluated based on the ISO 80601-2-61:2011 (E) guidelines. This study aimed to determine whether the various finger probes of the MP570T pulse oximeter (MEK-ICS Co., Ltd.

Optimal effect-site concentration of remifentanil to prevent hemodynamic changes during nasotracheal intubation using a video laryngoscope.

Background: Nasotracheal intubation is the most commonly used method to secure the field of view when performing surgery on the oral cavity or neck. Like orotracheal intubation, nasotracheal intubation uses a laryngoscope. Hemodynamic change occurs due to the stimulation of the sympathetic nervous system.