Associations between Clinicopathological Characteristics and Intraoperative Opioid Requirements during Endoscopic Submucosal Dissection with Monitored Anesthesia Care: A Retrospective Study.

Background and study aims: Endoscopic submucosal dissection is used to treat early gastric neoplasms. Compared with other endoscopic procedures, it requires higher doses of opioids, leading to adverse events during monitored anesthesia care. We investigated the correlations between clinicopathological characteristics and intraprocedural opioid requirements in patients who underwent endoscopic submucosal dissection under monitored anesthesia care. Patients and methods: The medical records of patients who underwent endoscopic submucosal dissection under monitored anesthesia care were retrospectively reviewed. The dependent variable was the total dose of fentanyl administered during the dissection, while independent variables were patient demographics, the American Society of Anesthesiologists physical status classification, preoperative vital sign data, and the pathological characteristics of the neoplasm. Correlations between variables were examined using multiple regression analysis. Results: The study included 743 patients. The median total fentanyl dose was 100 mcg. Younger age (coefficient -1.37; 95% confidence interval [CI] -1.78 to -0.95), male sex (16.12; 95% CI 6.99-25.24), baseline diastolic blood pressure (0.44; 95% CI 0.04-0.85), neoplasm length (1.63; 95% CI 0.90-2.36), and fibrosis (28.59; 95% CI 17.77-39.42) were positively correlated with the total fentanyl dose. Total fentanyl dose was higher in the differentiated (16.37; 95% CI 6.40-26.35) and undifferentiated cancers group (32.53; 95% CI 16.95-48.11) than in the dysplasia group; no significant differences were observed among the others. The mid-anterior wall (22.69; 95% CI 1.25-44.13), mid-posterior wall (29.65; 95% CI 14.39-44.91), mid-greater curvature (28.77; 95% CI 8.56-48.98), and upper groups (30.06; 95% CI 5.01-55.12) had higher total fentanyl doses than the lower group, whereas doses did not significantly differ for the mid-lesser curvature group. Conclusions: We identified variables that influenced opioid requirements during monitored anesthesia care for endoscopic submucosal dissection. These may help predict the needed opioid doses and identify factors affecting intraprocedural opioid requirements.

Machine learning with clinical and intraoperative biosignal data for predicting postoperative delirium after cardiac surgery.

Early identification of patients at high risk of delirium is crucial for its prevention. Our study aimed to develop machine learning models to predict delirium after cardiac surgery using intraoperative biosignals and clinical data. We introduced a novel approach to extract relevant features from continuously measured intraoperative biosignals. These features reflect the patient's overall or baseline status, the extent of unfavorable conditions encountered intraoperatively, and beat-to-beat variability within the data. We developed a soft voting ensemble machine learning model using retrospective data from 1,912 patients. The model was then prospectively validated with data from 202 additional patients, achieving a high performance with an area under the receiver operating characteristic curve of 0.887 and an accuracy of 0.881. According to the SHapley Additive exPlanation method, several intraoperative biosignal features had high feature importance, suggesting that intraoperative patient management plays a crucial role in preventing delirium after cardiac surgery.

Association between preoperative lumbar skeletal muscle index and postoperative nausea and vomiting in patients undergoing pylorus-preserving pancreatoduodenectomy: a retrospective study.

BACKGROUND: Sarcopenia is associated with postoperative complications; however, its impact on the quality of postoperative recovery, such as postoperative nausea and vomiting (PONV) and pain, remains unclear. We investigated the association of preoperative lumbar skeletal muscle mass index (LSMI) with PONV, postoperative pain, and complications. METHODS: Medical records of 756 patients who underwent pylorus-preserving pancreatoduodenectomy (PPPD) were retrospectively reviewed. The skeletal muscle areas were measured on abdominal computed tomography (CT) images. LSMI was calculated by dividing the skeletal muscle area by the square of the patient's height. We analyzed the correlations between preoperative LSMI calibrated with confounding variables and PONV scores, PONV occurrence, pain scores, rescue analgesic administration, postoperative complications, and length of hospital stay. RESULTS: The median (1Q, 3Q) LSMI was 47.72 (40.74, 53.41) cm2/m2. The incidence rates of PONV according to time period were as follows: post-anesthesia care unit, 42/756 (5.6%); 0-6 h, 54/756 (7.1%); 6-24 h, 120/756 (15.9%); 24-48 h, 46/756 (6.1%); and overall, 234/756 (31.0%). The incidence of PONV was inversely correlated with LSMI 24-48 h post-surgery and overall. LSMI and PONV scores were negatively associated 6-24 h and 24-48 h post-surgery. There was no association between LSMI and postoperative pain scores, rescue analgesic administration, complications, or length of hospital stay. CONCLUSIONS: Preoperative LSMI was associated with PONV in patients undergoing PPPD. Therefore, LSMI measured on preoperative abdominal CT can be a predictive indicator of PONV. Appropriate PONV prophylaxis is necessary in patients with low LSMI before PPPD.

Analysis of prognostic factors for postoperative complications and mortality in elderly patients undergoing emergency surgery for intestinal perforation or irreversible intestinal ischemia.

Purpose: Because the global geriatric population continues to increase, the assessment of emergency surgical outcomes in elderly patients with acute peritonitis will become more important. Methods: A retrospective review was conducted on the data of 174 elderly patients who underwent emergency surgery for intestinal perforation or intestinal infarction between June 2010 and November 2022. We conducted an analysis of the risk factors associated with postoperative complications and mortality by evaluating the characteristics of patients and their surgical outcomes. Results: In our study, most patients (94.3%) had preexisting comorbidities, and many patients (84.5%) required transfer to the intensive care unit following emergency surgery. Postoperative complications were observed in 84 individuals (48.3%), with postoperative mortality occurring in 29 (16.7%). Multivariate analysis revealed preoperative acute renal injury, hypoalbuminemia, and postoperative ventilator support as significant predictors of postoperative mortality. Conclusion: When elderly patients undergo emergency surgery for intestinal perforation or infarction, it is important to recognize that those with preoperative acute renal injury, hypoalbuminemia, and a need for postoperative ventilator support have a poor prognosis. Therefore, these patients require intensive care from the early stages of treatment.

Quantum LFSR Structure for Random Number Generation Using QCA Multilayered Shift Register for Cryptographic Purposes.

A random number generator (RNG), a cryptographic technology that plays an important role in security and sensor networks, can be designed using a linear feedback shift register (LFSR). This cryptographic transformation is currently done through CMOS. It has been developed by reducing the size of the gate and increasing the degree of integration, but it has reached the limit of integration due to the quantum tunneling phenomenon. Quantum-dot cellular automata (QCA), one of the quantum circuit design technologies to replace this, has superior performance compared to CMOS in most performance areas, such as space, speed, and power. Most of the LFSRs in QCA are designed as shift registers (SR), and most of the SR circuits proposed based on the existing QCA have a planar structure, so the cell area is large and the signal is unstable when a plane intersection is implemented. Therefore, in this paper, we propose a multilayered 2-to-1 QCA multiplexer and a D-latch, and we make blocks based on D-latch and connect these blocks to make SR. In addition, the LFSR structure is designed by adding an XOR operation to it, and we additionally propose an LFSR capable of dual-edge triggering. The proposed structures were completed with a very meticulous design technique to minimize area and latency using cell interaction, and they achieve high performance compared to many existing circuits. For the proposed structures, the cost and energy dissipation are calculated through simulation using QCADesigner and QCADesigner-E, and their efficiency is verified.

Non-Restoring Array Divider Using Optimized CAS Cells Based on Quantum-Dot Cellular Automata with Minimized Latency and Power Dissipation for Quantum Computing.

Many studies have addressed the physical limitations of complementary metal-oxide semi-conductor (CMOS) technology and the need for next-generation technologies, and quantum-dot cellular automata (QCA) are emerging as a replacement for nanotechnology. Meanwhile, the divider is the most-used circuit in arithmetic operations with squares and multipliers, and the development of effective dividers is crucial for improving the efficiency of inversion and exponentiation, which is known as the most complex operation. In most public-key cryptography systems, the corresponding operations are used by applying algebraic structures such as fields or groups. In this paper, an improved design of a non-restoring array divider (N-RAD) is proposed based on the promising technology of QCA. Our QCA design is focused on the optimization of dividers using controlled add/subtract (CAS) cells composed of an XOR and full adder. We propose a new CAS cell using a full adder that is designed to be very stable and compact so that power dissipation is minimized. The proposed design is considerably improved in many ways compared with the best existing N-RADs and is verified through simulations using QCADesigner and QCAPro. The proposed full adder reduces the energy loss rate by at least 25% compared to the existing structures, and the divider has about 23%~4.5% lower latency compared to the latest coplanar and multilayer structures.

Multi-Layered QCA Content-Addressable Memory Cell Using Low-Power Electronic Interaction for AI-Based Data Learning and Retrieval in Quantum Computing Environment.

In this study, we propose a quantum structure of an associative memory cell for effective data learning based on artificial intelligence. For effective learning of related data, content-based retrieval and storage rather than memory address is essential. A content-addressable memory (CAM), which is an efficient memory cell structure for this purpose, in a quantum computing environment, is designed based on quantum-dot cellular automata (QCA). A CAM cell is composed of a memory unit that stores information, a match unit that performs a search, and a structure, using an XOR gate or an XNOR gate in the match unit, that shows good performance. In this study, we designed an XNOR gate with a multilayer structure based on electron interactions and proposed a QCA-based CAM cell using it. The area and time efficiency are verified through a simulation using QCADesigner, and the quantum cost of the proposed XOR gate and CAM cell were reduced by at least 70% and 15%, respectively, when compared to the latest research. In addition, we physically proved the potential energy owing to the interaction between the electrons inside the QCA cell. We also proposed an additional CAM circuit targeting the reduction in energy dissipation that overcomes the best available designs. The simulation and calculation of power dissipation are performed by QCADesigner-E and it is confirmed that more than 27% is reduced.

The effect of oxygen concentration on atelectasis formation during induction of general anesthesia in children: A prospective randomized controlled trial.

BACKGROUND: In adults, the use of lower oxygen concentration during induction is associated with less atelectasis formation without an increase in incidence of hypoxia. However, it is unknown whether this remains true in the pediatric patients. METHODS: Fifty-four pediatric patients who were scheduled to undergo elective lower abdominal surgery were randomized to one of three oxygenation groups: 100%, 80%, or 60% oxygen (in air). During anesthesia induction, patients were ventilated with sevoflurane in 100%, 80%, or 60% oxygen. Endotracheal intubation and mechanical ventilation were performed. Atelectasis was diagnosed using LUS, which was performed after anesthetic induction and at the end of surgery. RESULTS: We assessed atelectasis after anesthetic induction and at the end of surgery. After anesthetic induction, the number of atelectatic lung regions was significantly different among the three groups (median [IQR], 2.0 [1.0-2.5], 2.0 [1.0-2.8], and 3.0 [2.0-3.0] in the 60%, 80%, and 100% oxygen groups, p = .033) and between the 60% and 100% groups (p = .015), but not between 80% and 100% groups (p = .074). However, no differences in the number of atelectatic lung regions were found among the three groups at the end of surgery (2.0 [1.3-3.8], 3.0 [1.8-3.0], and 4.0 [2.0-4.0] in the 60%, 80%, and 100% oxygen groups; p = .169). CONCLUSION: Lower oxygen concentration during anesthetic induction is associated with less atelectasis formation immediately after anesthetic induction in children. In addition, applying 80% oxygen instead of 100% oxygen is not enough to prevent atelectasis formation, and 60% oxygen should be applied to prevent atelectasis. However, this effect does not last until the end of surgery.

Reliability of Machine and Human Examiners for Detection of Laryngeal Penetration or Aspiration in Videofluoroscopic Swallowing Studies.

Computer-assisted analysis is expected to improve the reliability of videofluoroscopic swallowing studies (VFSSs), but its usefulness is limited. Previously, we proposed a deep learning model that can detect laryngeal penetration or aspiration fully automatically in VFSS video images, but the evidence for its reliability was insufficient. This study aims to compare the intra- and inter-rater reliability of the computer model and human raters. The test dataset consisted of 173 video files from which the existence of laryngeal penetration or aspiration was judged by the computer and three physicians in two sessions separated by a one-month interval. Intra- and inter-rater reliability were calculated using Cohen's kappa coefficient, the positive reliability ratio (PRR) and the negative reliability ratio (NRR). Intrarater reliability was almost perfect for the computer and two experienced physicians. Interrater reliability was moderate to substantial between the model and each human rater and between the human raters. The average PRR and NRR between the model and the human raters were similar to those between the human raters. The results demonstrate that the deep learning model can detect laryngeal penetration or aspiration from VFSS video as reliably as human examiners.

Hyoid Bone Tracking in a Videofluoroscopic Swallowing Study Using a Deep-Learning-Based Segmentation Network.

Kinematic analysis of the hyoid bone in a videofluorosopic swallowing study (VFSS) is important for assessing dysphagia. However, calibrating the hyoid bone movement is time-consuming, and its reliability shows wide variation. Computer-assisted analysis has been studied to improve the efficiency and accuracy of hyoid bone identification and tracking, but its performance is limited. In this study, we aimed to design a robust network that can track hyoid bone movement automatically without human intervention. Using 69,389 frames from 197 VFSS files as the data set, a deep learning model for detection and trajectory prediction was constructed and trained by the BiFPN-U-Net(T) network. The present model showed improved performance when compared with the previous models: an area under the curve (AUC) of 0.998 for pixelwise accuracy, an accuracy of object detection of 99.5%, and a Dice similarity of 90.9%. The bounding box detection performance for the hyoid bone and reference objects was superior to that of other models, with a mean average precision of 95.9%. The estimation of the distance of hyoid bone movement also showed higher accuracy. The deep learning model proposed in this study could be used to detect and track the hyoid bone more efficiently and accurately in VFSS analysis.

Perforation on the superior side of duodenum is a risk factor of laparoscopic primary repair for duodenal ulcer perforation.

PURPOSE: Primary repair is the standard surgical method for treating duodenal ulcer perforations, with very good results usually anticipated because of the simplicity of the associated surgical techniques. Therefore, this study aimed to analyze the risk factors that affect laparoscopic primary repair outcomes for duodenal ulcer perforation. METHODS: Between June 2010 and June 2020, 124 patients who underwent laparoscopic primary repair for duodenal ulcer perforations were reviewed. Early surgical outcomes were evaluated and risk factors for postoperative complications were assessed. RESULTS: All surgeries were performed laparoscopically without open conversion. Multivariate analysis showed that the elderly (over 70 years), and perforations that needed more than 2 stitches for closure were risk factors for overall postoperative complications. Perforations that needed more than 2 stitches and perforations on the superior side of the duodenum were major risk factors for severe postoperative complications. Severe postoperative complications occurred in 6 of the patients, and 1 of them died of multiorgan failure. CONCLUSION: Based on our results, we suggest that laparoscopic primary repair can be safely performed in duodenal ulcer perforation. However, more careful surgery and postoperative care are needed to improve the surgical outcomes of patients who need more than 2 stitches to close their perforation or who have perforations on the superior side of the duodenum.

A novel electromagnetic guidance ultrasound system on radial artery cannulation: a prospective randomized controlled trial.

BACKGROUND: Radial artery cannulation can cause complications such as haematoma formation or thrombosis due to its small diameter. Recently, a novel ultrasound device equipped with an electromagnetic guidance system was introduced, showing the path and alignment of the needle during the procedure. The aim of this study was to investigate the effects of this novel system on both success and complication rates during radial artery cannulation under ultrasound guidance. METHODS: In this randomized controlled trial, 76 adults scheduled for neurosurgery requiring radial artery cannulation were recruited. In group E (n = 38), radial artery cannulation was performed using the electromagnetic guidance ultrasound system, whereas in group C (n = 38), the procedure was performed using conventional ultrasound guidance. The success rates of cannulation on the first attempt, cannulation times, number of attempts, and incidence of complications were compared between the two groups. RESULTS: There was a significant difference in the success rates on the first attempt between the two groups (group C = 78.9% vs. group E = 94.7%, P = 0.042). Incidences of posterior wall puncture and haematoma formation (group C = 8 vs. group E = 1; P = 0.028) were significantly lower in group E than in group C. The median cannulation time for successful attempts was comparable between groups. CONCLUSIONS: Use of the novel electromagnetic guidance system resulted in a better success rate on the first attempt and a lower incidence of complications during radial artery cannulation. TRIAL REGISTRATION: This study was registered at http://cris.nih.go.kr (registration number: KCT0002476 ).

Cross-sectional association between long working hours and liver function: the Kangbuk Samsung Health Study.

OBJECTIVES: Although the effects of long working hours on liver function remain unclear, in South Korea, there is a social perception that long working hours are associated with poor liver function. Thus, long working hours have recently become a major issue. This study aimed to determine the association between long working hours and liver function, as indicated by the alanine transaminase (ALT) levels. DESIGN: Cross-sectional study. SETTING: Large university hospitals in Seoul and Suwon, South Korea. PARTICIPANTS: Workers in formal employment who underwent a comprehensive health examination at the Kangbuk Samsung Hospital Total Healthcare Centre clinics in Seoul and Suwon, South Korea, between January 2011 and December 2018. Of the 386 488 participants, 212 421 met the inclusion criteria and were included in the analysis. PRIMARY OUTCOME MEASURE: ALT elevation. RESULTS: The participants were predominantly well-educated (86.1%), male (69.3%) and in their 30s (49.6%). In total, 13.4% of the participants presented ALT elevation (>40 IU/L). There was no significant association between working hours and ALT elevation in the general population and in the hepatitis B surface antigen (HBsAg)-negative group. Conversely, in the HBsAg-positive group, working >60 hours per week compared with 35-40 hours per week was significantly associated with ALT elevation. The association was more pronounced in those with ALT levels >80 IU/L (OR 1.94, 95% CI 1.24 to 3.01) than in those with ALT levels >40 IU/L (OR: 1.45, 95% CI 1.20 to 1.75). The p values for trend were <0.05. CONCLUSIONS: Long working hours were associated with ALT elevation only in hepatitis B virus carriers and not in the general population. Provided that there is adherence to the legal working hours, there is no need to further restrict working hours for liver health, irrespective of HBsAg status.

Mental health impact on a humidifier disinfectant disaster victim: a case report.

In Korea, the cause of lung disease of unknown origin was identified as humidifier disinfectants in November 2011. In February 2017, the 'Special Act on Remedy for Damage Caused by Humidifier Disinfectants' was promulgated. Even though emotional and mental injuries caused by humidifier disinfectants have been reported, the focus of the special act has been on physical injury only, and criteria for recognizing mental health impact have not been considered. This case considers emotional and mental injury caused by humidifier disinfectants. After a humidifier disinfectant was used from January 2005 to April 2006, the patient's son aged 20 months was hospitalized with respiratory symptoms, and he died within two weeks. Also, the patient was hospitalized for a month with the same symptoms, and then she led a normal life with no symptoms. After both mother and son were diagnosed with definite (level 1) humidifier disinfectant lung injury (HDLI) in 2017, she took to drinking alcohol because of extreme guilt over her son's death. In March 2018 she died from acute liver failure due to alcohol use disorder. The patient's death was caused by continuous alcoholism, due to emotional and mental trauma caused by her son's death after HDLI was revealed as the cause. The government did not acknowledge her death was due to humidifier disinfectants, but the company that sold the humidifier disinfectants recognized her as a victim and compensated the family of the victim. There are still lots of psychological responses among humidifier disinfectant disaster victims. Mental health impact on humidifier disinfectant victims should be considered more carefully, and institutional improvements should be made into establish psychological interventions and measures.

Surgical Outcomes and Survival Prognostic Factors for Palliative Gastrectomies in Stage IV Resectable Gastric Cancer Outlet Obstruction Patients.

PURPOSE: Currently, there is no clear evidence to support any specific treatment as a principal therapy for stage IV gastric cancer outlet obstruction (GCOO) patients. This study evaluated the outcomes of palliative gastrectomies and survival prognostic factors in patients with stage IV resectable GCOO. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 48 stage IV GCOO patients who underwent palliative gastrectomies between June 2010 and December 2019. Palliative gastrectomies were performed only in patients with resectable disease. Early surgical outcomes and prognostic factors were analyzed using univariate and multivariate analyses. RESULTS: There were no specific risk factors for postoperative complications, except for being underweight. Severe postoperative complications developed in five patients, and most of the patients underwent interventional procedures and received broad-spectrum antibiotics for intra-abdominal abscesses. The multivariate survival analysis showed that palliative chemotherapy is a positive prognostic factor, while the specific type of hematogenous and lymphatic metastasis is a negative prognostic factor. CONCLUSIONS: We recommend that the treatment method for stage IV GCOO should be selected according to each patient's physical condition and tumor characteristics. In addition, we suggest that palliative gastrectomies can be performed in stage IV resectable GCOO patients without unfavorable prognostic factors (types of hematogenous and lymphatic metastases).

Factors affecting determination of the optimal ketamine dose for pediatric sedation.

OBJECTIVE: Children are sedated before undergoing diagnostic imaging tests in emergency medicine or pediatric sedation anesthesia units. The aim of this study was to identify variables potentially affecting the dose of ketamine required for induction of sedation in pediatric patients undergoing diagnostic imaging. METHODS: This retrospective study included children aged 0 to 18 years who underwent sedation with ketamine for computed tomography or magnetic resonance imaging in the pediatric sedation anesthesia unit of a tertiary medical center between January 2011 and August 2016. The children's hemodynamic status and depth of sedation were monitored during the examination. We recorded data on demographics, categories of imaging tests, ketamine doses administered, adverse events, respiratory interventions, and duration of sedation. Data for patients who experienced adverse events were excluded. RESULTS: Sixty-six patients were included in the final analysis. Univariate linear regression analysis revealed that patient age, height, and body surface area (BSA) affected the sedative dose of ketamine administered. These three variables showed multicollinearity in multivariate linear regression analysis and were analyzed in three separate models. The model with the highest adjusted R-squared value suggested the following equation for determination of the dose of ketamine required to induce sedation: ketamine dose (mg)=-1.62+0.7×age (months)+36.36×BSA (m2). CONCLUSION: Variables such as age and BSA should be considered when estimating the dose of ketamine required for induction of sedation in pediatric patients.

Non-clinical pharmacokinetic behavior of ginsenosides.

Ginsenosides, the major active ingredients of ginseng and other plants of the genus Panax, have been used as natural medicines in the East for a long time; in addition, their popularity in the West has increased owing to their various beneficial pharmacological effects. There is therefore a wealth of literature regarding the pharmacological effects of ginsenosides. In contrast, there are few comprehensive studies that investigate their pharmacokinetic behaviors. This is because ginseng contains the complicated mixture of herbal materials as well as thousands of constituents with complex chemical properties, and ginsenosides undergo multiple biotransformation processes after administration. This is a significant issue as pharmacokinetic studies provide crucial data regarding the efficacy and safety of compounds. Moreover, there have been many difficulties in the development of the optimal dosage regimens of ginsenosides and the evaluation of their interactions with other drugs. Therefore, this review details the pharmacokinetic properties and profiles of ginsenosides determined in various animal models administered through different routes of administration. Such information is valuable for designing specialized delivery systems and determining optimal dosing strategies for ginsenosides.

A radioactive material monitoring system using multiple gamma spectroscopy detectors and centroid method.

A radioactive material monitoring system, employing a passive detection technique with multiple gamma spectroscopy detectors and the centroid method for use in large areas, is presented. The system determines the location and the activity of radioisotopes. The proposed system was designed and evaluated using Monte Carlo simulations and experiments. In both simulation and experiment, calculated source locations were well distinguished and the location was determined within less than 1m range compared to the actual location. The calculated activity was matched to the actual activity within an error of 5%.

Measuring the depth of the caudal epidural space to prevent dural sac puncture during caudal block in children.

BACKGROUND: Caudal blocks are performed through the sacral hiatus in order to provide pain control in children undergoing lower abdominal surgery. During the block, it is important to avoid advancing the needle beyond the sacrococcygeal ligament too much to prevent unintended dural puncture. This study used demographic data to establish simple guidelines for predicting a safe needle depth in the caudal epidural space in children. METHODS: A total of 141 children under 12 years old who had undergone lumbar-sacral magnetic resonance imaging were included. The T2 sagittal image that provided the best view of the sacrococcygeal membrane and the dural sac was chosen. We used Picture Achieving and Communication System (Centricity® PACS, GE Healthcare Co.) to measure the distance between the sacrococcygeal ligament and the dural sac, the length of the sacrococcygeal ligament, and the maximum depth of the caudal space. RESULTS: There were strong correlations between age, weight, height, and BSA, and the distance between the sacrococcygeal ligament and dural sac, as well as the length of the sacrococcygeal ligament. Based on these findings, a simple formula to calculate the distance between the sacrococcygeal ligament and dural sac was developed: 25 × BSA (mm). CONCLUSION: This simple formula can accurately calculate the safe depth of the caudal epidural space to prevent unintended dural puncture during caudal block in children. However, further clinical studies based on this formula are needed to substantiate its utility.

Low Serum Albumin Level, Male Sex, and Total Gastrectomy Are Risk Factors of Severe Postoperative Complications in Elderly Gastric Cancer Patients.

PURPOSE: It is well known that old age is a risk factor for postoperative complications. Therefore, this study aimed to explore the risk factors for poor postoperative surgical outcomes in elderly gastric cancer patients. MATERIALS AND METHODS: Between January 2006 and December 2015, 247 elderly gastric cancer patients who underwent curative gastrectomy were reviewed. In this study, an elderly patient was defined as a patient aged ≥65 years. All possible variables were used to explore the risk factors for poor early surgical outcomes in elderly gastric cancer patients. RESULTS: Based on multivariate analyses of preoperative risk factors, preoperative low serum albumin level (<3.5 g/dl) and male sex showed statistical significance in predicting severe postoperative complications. Additionally, in an analysis of surgery-related risk factors, total gastrectomy was a risk factor for severe postoperative complications. CONCLUSIONS: Our study findings suggest that low serum albumin level, male sex, and total gastrectomy could be risk factors of severe postoperative complications in elderly gastric cancer patients. Therefore, surgeons should work carefully in cases of elderly gastric cancer patients with low preoperative serum albumin level and male sex. We believe that efforts should be made to avoid total gastrectomy in elderly gastric cancer patients.