Maintaining tissue perfusion, thus, obtaining optimal oxygen delivery to the tissue is the final goal of hemodynamic monitoring. Cardiac output is the most valuable parameter among the hemodynamic variables. Although there is no true reference for the cardiac output monitoring, thermodilution cardiac output remains the current clinical standard for measuring cardiac output. New cardiac output techniques are compared with thermodilution method in accuracy and relevance, although thermodilution cardiac output monitoring has been shown to increase the morbidity and mortality, and be inaccurate in several clinical settings. New techniques of cardiac output monitoring have been introduced to increase the safety, convenience, accuracy and reproducibility. Especially, to decrease the time-delay of therapeutic intervention, continuous monitoring is preferred. Among these, partial CO2 rebreathing technique based on Fick principle and esophageal Doppler technique are optimal for intraoperative and intensive care settings during mechanical ventilation. They are non- or minimally invasive methods and don't need that much extra training to operate the machines. Esophageal Doppler monitoring provides further data on preload and contractility, but partial CO2 rebreathing technique does not. In case of cardiac or pulmonary dysfunction, cardiac output monitoring technique which could give more information about preload is beneficial. In cardiac surgery, transesophageal echocardiogram is getting to substitute for pulmonary artery catheter for cardiac output monitoring. For cardiac output monitoring, less invasive, more accurate, and continuous technique is preferred, but it should be chosen according to the clinical setting such as type of operation and cardiac and/or pulmonary function of the patient.
Cardiac Output* ; Catheters ; Hemodynamics ; Humans ; Critical Care ; Mortality ; Oxygen ; Perfusion ; Pulmonary Artery ; Respiration, Artificial ; Thermodilution ; Thoracic Surgery

The term minimally invasive cardiac surgery encompasses a number of different techniques, from minimally invasive direct coronary artery bypass grafting without the use of cardiopulmonary bypass to telemanipulation and computer-enhanced robot-directed surgery. The hoped-for benefits from minimally invasive surgery are less pain, less disfiguring, fewer blood transfusions, earlier return to activity, and lower cost. The technology involved in reducing surgical trauma and limiting the physiologic trespass of cardiac surgery on the patients concerns not only surgical instrumentation but also anesthetic management. Anesthetic plan includes one lung isolation, careful monitoring of hemodynamics and gas exchange, fast track technique, appropriate analgesia strategies, and the use of transesophageal echocardiography for evaluation of the heart and positioning of cannulae. A better understanding of these newer, unconventional surgical operations enables cardiac anesthesiologists to contribute to favorable outcomes.
Analgesia ; Blood Transfusion ; Cardiopulmonary Bypass ; Catheters ; Coronary Artery Bypass ; Echocardiography, Transesophageal ; Heart ; Hemodynamics ; Humans ; Lung ; Surgical Instruments ; Thoracic Surgery ; Track and Field

PURPOSE: The aim of the study was to investigate associations of spiritual well-being, attitude toward death, and quality of life among Alcoholics Anonymous (AA). METHODS: This study was cross-sectional and descriptive in design. The data was collected from August to September 2018 with 133 AA members drawn from two provinces of South Korea. The data were analyzed using descriptive statistics, independent t-tests, one-way ANOVA with Turkey tests, Pearson's correlation coefficients, and hierarchical multiple linear regression analyses using SPSS/WIN 20.0 program. RESULTS: The existential spiritual well-being (β=.52, p<.001), attitude toward death (β=.24, p<.001), dual diagnosis (β=−.17, p=.003), occupation (β=.12, p=.035) of the participants were significant factors, which explained 63.7% of the variance of quality of life. CONCLUSION: The study findings highlight the need to develop psychological nursing strategies to enhance the spiritual well-being and improve a positive attitude toward death based on the job and dual diagnosis among AA members to improve their better quality of life.
Alcohol-Related Disorders ; Alcoholics Anonymous ; Alcoholics ; Attitude to Death ; Diagnosis, Dual (Psychiatry) ; Humans ; Korea ; Linear Models ; Nursing ; Occupations ; Quality of Life ; Spirituality ; Turkey

Directed acyclic graphs (DAGs) are useful tools for visualizing the hypothesized causal structures in an intuitive way and selecting relevant confounders in causal inference. However, in spite of their increasing use in clinical and surgical research, the causal graphs might also be misused by a lack of understanding of the central principles. In this article, we aim to introduce the basic terminology and fundamental rules of DAGs, and DAGitty, a user-friendly program that easily displays DAGs. Specifically, we describe how to determine variables that should or should not be adjusted based on the backdoor criterion with examples. In addition, the occurrence of the various types of biases is discussed with caveats, including the problem caused by the traditional approach using p-values for confounder selection. Moreover, a detailed guide to DAGitty is provided with practical examples regarding minimally invasive surgery. Essentially, the primary benefit of DAGs is to aid researchers in clarifying the research questions and the corresponding designs based on the domain knowledge. With these strengths, we propose that the use of DAGs may contribute to rigorous research designs, and lead to transparency and reproducibility in research on minimally invasive surgery.

Traditional mediation analysis, which relies on linear regression models, has faced criticism due to its limited suitability for cases involving different types of variables and complex covariates, such as interactions. This can result in unclear definitions of direct and indirect effects. As an alternative, causal mediation analysis using the counterfactual framework has been introduced to provide clearer definitions of direct and indirect effects while allowing for more flexible modeling methods. However, the conceptual understanding of this approach based on the counterfactual framework remains challenging for applied researchers. To address this issue, the present article was written to highlight and illustrate the definitions of causal estimands, including controlled direct effect, natural direct effect, and natural indirect effect, based on the key concept of nested counterfactuals. Furthermore, we recommend using 2 R packages, ‘medflex’ and ‘mediation’, to perform causal mediation analysis and provide public health examples. The article also offers caveats and guidelines for accurate interpretation of the results.

Background: Conventional laryngoscopy with Macintosh blade requires a movement of the head, neck and cervical spine. The Bullard laryngoscope is an anatomically shaped, potentially eliminating the need for cervical spine extension. Bullard and Macintosh laryngoscopes were compared by measuring the degree of cervical spine extension by radiological measurement. Methods: Eighteen patients requiring endotracheal intubation were studied. Anesthesia was induced in neutral head position followed by laryngoscopy. Each patients was intubated two times by Macintosh and Bullard laryngoscope in random order. Radiographic evaluation was performed to determine the degree of cervical spine extension on four occasions; before induction, during facial mask ventilation, and during Bullard and Macintosh laryngoscopy. Results: The extension of cervical spine was significantly less following Bullard laryngoscopy than Macintosh laryngoscopy for best view (p<0.05). Conclusions: The Bullard laryngoscope can be used with less cervical spine extension than Macintosh laryngoscope. It may be useful in patients in whom cervical spine movement is limited or undesirable.
Anesthesia ; Head ; Humans ; Intubation, Intratracheal ; Laryngoscopes ; Laryngoscopy* ; Masks ; Neck ; Spine* ; Ventilation

The purpose of this simulation study is to explore the limitation of the population PK/PD analysis using data from a clinical study and to help to construct an appropriate PK/PD design that enable precise and unbiased estimation of both fixed and random PD parameters in PK/PD analysis under different doses and Hill coefficients. Seven escalating doses of virtual drugs with equal potency and efficacy but with five different Hill coefficients were used in simulations of single and multiple dose scenarios with dense sampling design. A total of 70 scenarios with 100 subjects were simulated and estimated 100 times applying 1-compartment PK model and sigmoid E(max) model. The bias and precision of the parameter estimates in each scenario were assessed using relative bias and relative root mean square error. For the single dose scenarios, most PD parameters of sigmoid E(max) model were accurately and precisely estimated when the C(max) was more than 85% of EC₅₀, except for typical value and inter-individual variability of EC₅₀ which were poorly estimated at low Hill coefficients. For the multiple dose studies, the parameter estimation performance was not good. This simulation study demonstrated the effect of the relative range of sampled concentrations to EC₅₀ and sigmoidicity on the parameter estimation performance using dense sampling design.
Bias (Epidemiology) ; Clinical Study ; Colon, Sigmoid*

Electrophysiological research has improved the understandings of various neural controls on motion and their functional connectivity in the central nervous system. Unlike medical imaging techniques, the electrophysiological approach can provide the neural signal processing between two or more specific regions and their temporal transmission of neural information. Using its unique advantages, the vestibular system has been also studied for more than 100 years. However, it is a recent finding that various higher functions, such as cognition, memory, learning, and even spatial navigation, are constructed partially by the vestibular neural information in the human brain. It is caused by the historical underestimation on the vestibular system and its supporting position to the main neural flow. Here, we seek for a new research theme with various approaches in the vestibular system by reviewing electrophysiological researches on the vestibular system and their experimental results.
Brain ; Central Nervous System ; Cognition ; Diagnostic Imaging ; Electrophysiology* ; Humans ; Learning ; Memory

OBJECTIVE: Growing hypotheses indicate the galvanic vestibular stimulation (GVS) as an alternative method to manage the symptoms of parkinson's disease (PD). GVS is easy and safe for use, and non-invasive. However, it is elusive how the neural information caused by GVS is transmitted in the central nervous system and relieves PD symptoms. To answer this question, we investigated the transmission of neural information by GVS in the central vestibular system, focused on vestibular nucleus (VN). METHODS: Twenty guinea pigs were used for this study for the extracellular neuronal recordings in the VN. The neuronal responses to rotation and GVS were analyzed by curve-fitting, and the numerical responding features, amplitudes and baselines, were computed. The effects of stimuli were examined by comparing these features. RESULTS: Twenty six vestibular neurons (15 regular and 11 irregular neurons) were recorded. Comparing the difference of baselines, we found the neural information was linearly transmitted with a reduced sensitivity (0.75). The linearity in the neural transmission was stronger in the neuronal groups with regular (correlation coefficient [Cor. Coef.]=0.91) and low sensitive units (Cor. Coef.=0.93), compared with those with irregular (Cor. Coef.=0.86) and high-sensitive neurons (Cor. Coef.=0.77). CONCLUSION: The neural information by GVS was linearly transmitted no matter what the neuronal characteristics were.
Animals ; Central Nervous System ; Guinea Pigs ; Methods ; Neurons ; Parkinson Disease ; Synaptic Transmission ; Vestibular Nuclei

Purpose: This study aimed to provide the descriptive statistics regarding the injury epidemiology of Korean professional basketball players. Methods: In this study, athlete exposures (AEs) and time exposures (TEs) were collected from the 38 basketball players (17 women) who participated in the 2019–2020 regular season. Injury rate (IR) and 95% confidence interval (CI) were calculated. Results: A total of 35 injuries were reported. The overall rate of injury was 5.65 per 1,000 AEs and 0.06 per 1,000 TEs. Approximately 65.7% of all the injuries occurred during the official games, with lower limb injuries accounting for about 57.1% of all the injuries. Ankle was the most frequently injured body area (25.7%) with a IR of 1.45 per 1,000 AEs. Sprain accounted for the largest portion with 54.3% overall, followed by strain, contusion and cartilage damage. The most common cause of injuries was contact with another athletes (37.2%), and the recurrence of past injuries (20.0%) also accounted for a high proportion. Conclusion Korean professional basketball players experience a high rate of injuries occurring during official games.Ankle sprains were the most common ones. Contact-caused injuries accounted for the highest portion.