Frequently, we encounter the phenomenon of hysteresis in kinetic-dynamic modeling. The hysteresis loop in the concentration-effect curve suggests a time discrepancy caused by various pharmacokinetic and pharmacodynamic factors. To collapse the hysteresis loop and to simplify the concentration-effect relationship, several kinetic-dynamic modeling approaches including the effect compartment link model, turnover model (indirect response model), and tolerance/rebound model, have been used. The semicompartmental model is one method to describe the hysteresis of the pharmacokineticpharmacodynamic relationship. Furthermore, this semi-compartmental model differs from other models (full parametric approaches) as it does not require pharmacokinetic parameters to estimate pharmacodynamic parameters and ke0. Therefore, we could employ a semi-compartmental approach in case it is difficult to apply the compartment model to pharmacokinetic data, as required for the pharmacodynamic analysis of inhalational anesthetics.

Central venous catheterization is a useful method for monitoring central venous pressure and maintaining volume status. However, it is associated with several complications, such as pneumothorax, hydrothorax, hemothorax, and air embolism. Here we describe a case of iatrogenic tension hydrothorax after rapid infusion of fluid into the pleural space, following the misplacement of an internal jugular vein catheter. Despite ultrasonographic guidance during insertion of the central venous catheter, we were not able to avoid malposition of the catheter. The patient went into hemodynamic compromise during surgery, necessitating chest tube drainage and a mechanical ventilator postoperatively. This case shows that central venous catheter insertion under ultrasonographic guidance does not guarantee proper positioning of the catheter.
Catheterization, Central Venous ; Catheters ; Central Venous Catheters* ; Central Venous Pressure ; Chest Tubes ; Drainage ; Embolism, Air ; Hemodynamics ; Hemothorax ; Humans ; Hydrothorax* ; Jugular Veins ; Methods ; Pneumothorax ; Ventilators, Mechanical

BACKGROUND: Approximately 90%~99% of ultraviolet A (UVA) ray reaches the Earth's surface. The deeply penetrating UVA rays induce the formation of reactive oxygen species (ROS), which results in oxidative stress such as photoproducts, senescence, and cell death. Thus, UVA is considered a primary factor that promotes skin aging. OBJECTIVE: Researchers investigated whether pretreatment with ferulic acid protects human dermal fibroblasts (HDFs) against UVA-induced cell damages. METHODS: HDF proliferation was analyzed using the water-soluble tetrazolium salt assay. Cell cycle distribution and intracellular ROS levels were assessed by flow cytometric analysis. Senescence was evaluated using a senescence-associated β-galactosidase assay, while Gadd45α promoter activity was analyzed through a luciferase assay. The expression levels of superoxide dismutase 1 (SOD1), catalase (CAT), xeroderma pigmentosum complementation group A and C, matrix metalloproteinase 1 and 3, as well as p21 and p16 were measured using quantitative real-time polymerase chain reaction. RESULTS: Inhibition of proliferation and cell cycle arrest were detected in cells that were irradiated with UVA only. Pretreatment with ferulic acid significantly increased the proliferation and cell cycle progression in HDFs. Moreover, ferulic acid pretreatment produced antioxidant effects such as reduced DCF intensity, and affected SOD1 and CAT mRNA expression. These effects were also demonstrated in the analysis of cell senescence, promoter activity, expression of senescent markers, and DNA repair. CONCLUSION: These results demonstrate that ferulic acid exerts protective effects on UVA-induced cell damages via anti-oxidant and stress-inducible cellular mechanisms in HDFs.
Aging ; Animals ; Antioxidants ; Catalase ; Cats ; Cell Aging ; Cell Cycle ; Cell Cycle Checkpoints ; Cell Death ; Complement System Proteins ; DNA Repair ; Fibroblasts* ; Humans* ; Luciferases ; Matrix Metalloproteinase 1 ; Oxidative Stress ; Reactive Oxygen Species ; Real-Time Polymerase Chain Reaction ; RNA, Messenger ; Skin Aging ; Superoxide Dismutase ; Ultraviolet Rays ; Xeroderma Pigmentosum

No abstract available.
Esophagitis* ; Nitric Oxide ; Sucralfate*

No abstract available.
Anesthesia, Spinal*

OBJECTIVES: In vestibular neuritis (VN), the lesion preferentially affects the superior vestibular nerve because of the anatomic arrangement. It is well known that VN patients have a higher score of metabolic syndrome or a higher incidence of vertebral artery hypoplasia than controls. However, it is unclear whether the frequency of cardiovascular risk factors can affect the selective involvement of the branch of the vestibular nerve. Thus, we investigated the influence of cardiovascular risk factors on the development of total- or divisional VN. METHODS: 61 patients with VN were enrolled. Video head impulse tests and caloric tests were performed to determine which vestibular divisionswere affected. The patients were divided into divisional-VN (superior or inferior) and total-VN groups. Statistical analysis of the frequency of cardiovascular risk factors was performed only in superior and total VN groups because the number of inferior VN patients was too small to be statistically analyzed. RESULTS: Nineteen (31.1%) patients were classified as the total-VN group. In the divisional-VN group (42 patients, 65.6%), 40 were superior VN. The frequency of cardiovascular risk factors are not significantly different in superior VN and total-VN groups (All patients 50/61 [82.0%], superior-VN 36/40 [90.0%], total-VN 13/19 [68.4%]). The frequency of having more than one cardiovascular risk factor was slightly higher in the superior VN group, (13 [68.4%] vs. 36 [90.0%], p=0.062) but did not show any significant difference. CONCLUSIONS: The number of cardiovascular risk factors did not differ in superior VN patients compared to total VN patients.
Caloric Tests ; Cardiovascular Diseases ; Head Impulse Test ; Humans ; Incidence ; Risk Factors ; Vertebral Artery ; Vestibular Nerve ; Vestibular Neuronitis

Background: The depth of anesthesia is an essential factor in surgical prognosis. The neurotoxic effect of chemotherapeutic drugs affects the sensitivity to anesthetics. This study was conducted to determine whether the effect-site concentration (Ce) of propofol for loss of consciousness (LOC) differs in patients undergoing preoperative chemotherapy. Methods: A total of 60 patients scheduled for surgery for colorectal cancer under general anesthesia were included in this study. Patients who had received chemotherapy comprised the experimental (C) group, and those without a previous history of chemotherapy comprised the control (N) group. Propofol was administered as an effect-site target-controlled infusion, and the Modified Observer’s Assessment of Alertness/Sedation (MOAA/S) scores were evaluated. When the plasma concentration and Ce were similar, and if the MOAA/S score did not change, the target Ce was increased by 0.2 μg/ml; otherwise, the Ce was maintained for 2 min and then increased. Results: The Ce values of propofol for loss of verbal contact (LVC) in groups C and N were 2.40 ± 0.39 and 2.29 ± 0.39 μg/ml (P = 0.286), respectively, and those for LOC in groups C and N were 2.69 ± 0.43 and 2.50 ± 0.36 μg/ml (P = 0.069), respectively. No significant difference was observed in Ce values between the two groups. Conclusions Chemotherapy had no effect on the Ce of propofol for LVC and LOC in patients with colorectal cancer. We do not recommend reducing the dose of propofol for the induction of LOC in patients with colorectal cancer undergoing chemotherapy.

Background: Difficult airway occurs due to anatomical abnormalities of the airway that can be predicted through airway assessments; however, abnormalities beyond the vocal cord can be clinically asymptomatic and undetected until intubation failure to advance the endotracheal tube.Case: We present a case of an unanticipated difficult airway in a stuporous 80-year-old female with a recent history of intracerebral hemorrhage and prolonged intubation. She required emergency ventriculo-peritoneal shunt surgery due to the progression of her hydrocephalus. Under anesthesia, facemask ventilation was easy and video laryngoscopy provided a full view of the glottis; however, endotracheal tube (ETT) entry failed. We suspected stenosis beyond the vocal cord, and a smaller diameter ETT was inserted and maintained for airway management during emergency surgery. Postoperative neck computed tomography findings revealed laryngotracheal stenosis (LTS). Conclusions Anesthesiologists should be aware that LTS may be asymptomatic and consider difficult airway guidelines in patients with history of prolonged endotracheal intubation.

Background: Differences in the effects of propofol and dexmedetomidine sedation on electroencephalogram patterns have been reported previously. However, the reliability of the Bispectral Index (BIS) value for assessing the sedation caused by dexmedetomidine remains debatable. The purpose of this study is to evaluate the correlation between the BIS value and the Modified Observer’s Assessment of Alertness/Sedation (MOAA/S) scale in patients sedated with dexmedetomidine. Methods: Forty-two patients (age range, 20–80 years) who were scheduled for elective surgery under spinal anesthesia were enrolled in this study. Spinal anesthesia was performed using 0.5% bupivacaine, which was followed by dexmedetomidine infusion (loading dose, 0.5–1 μg/kg for 10 min; maintenance dose, 0.3–0.6 μg/kg/h). The MOAA/S score was used to evaluate the level of sedation, and the Vital Recorder program was used to collect data (vital signs and BIS values). Results: A total of 215082 MOAA/S scores and BIS data pairs were analyzed. The baseline variability of the BIS value was 7.024%, and the decrease in the BIS value was associated with a decrease in the MOAA/S score. The correlation coefficient and prediction probability between the two measurements were 0.566 (P < 0.0001) and 0.636, respectively. The mean ± standard deviation values of the BIS were 87.22 ± 7.06, 75.85 ± 9.81, and 68.29 ± 12.65 when the MOAA/S scores were 5, 3, and 1, respectively. Furthermore, the cut-off BIS values in the receiver operating characteristic analysis at MOAA/S scores of 5, 3, and 1 were 82, 79, and 73, respectively. Conclusion The BIS values were significantly correlated with the MOAA/S scores. Thus, the BIS along with the clinical sedation scale might prove useful in assessing the hypnotic depth of a patient during sedation with dexmedetomidine.

Some studies have demonstrated that chemotherapy drugs enhance sensitivity to anesthetics owing to its systemic toxicity, while others have demonstrated that chemotherapy drugs have no effect. This study aimed to determine whether neoadjuvant chemotherapy influences the effect-site concentration (Ce) of propofol for sedation in patients withbreast cancer.Methods: This study included patients aged 19–75 years who were scheduled to undergobreast cancer surgery under general anesthesia. Patients who received neoadjuvant chemotherapy were assigned to group C, whereas those who never received chemotherapy wereassigned to group N. Propofol was administered through an effect-site target-controlled infusion, and the Modified Observer’s Assessment of Alertness/Sedation scale (MOAA/S) scoreand Bispectral Index (BIS) were recorded. When the plasma concentration and Ce wereequal to the target Ce, and if the MOAA/S score did not change, the target Ce was increasedby 0.2 μg/ml; otherwise, the Ce was maintained for 2 min and then increased. This processwas repeated until the MOAA/S score became 0.Results: No significant differences were observed in Ce values at each sedation level between both groups. Ce values for loss of consciousness (LOC) of groups C and N were 2.76± 0.29 and 2.67 ± 0.27 μg/ml (P = 0.285), respectively. However, the BIS value at LOC ofgroup C (63.87 ± 7.04) was lower than that (68.44 ± 6.01) of group N (P = 0.018).Conclusions: Neoadjuvant chemotherapy for breast cancer has no effect on the Ce ofpropofol for sedation.