Patient, provider, and system-level factors associated with preoperative cardiac testing: A systematic review.

BACKGROUND: Overuse of preoperative cardiac testing contributes to high healthcare costs and delayed surgeries. A large body of research has evaluated factors associated with variation in preoperative cardiac testing. However, patient, provider, and system-level factors associated with variation in testing have not been systematically studied. OBJECTIVE: To conduct a systematic review to better delineate the patient, provider, and system-level factors associated with variation in preoperative cardiac testing. METHODS: We included studies of an adult US population evaluating a patient, provider, or system-level factor associated with variation in preoperative cardiac testing for noncardiac surgery since 2012. Our search strategy used terms related to preoperative testing, diagnostic cardiac tests, and care variation with Ovid MEDLINE and Embase from inception through January 2023. We extracted study characteristics and factors associated with variation and qualitatively analyzed them. We assessed risk of bias using the Newcastle-Ottawa Scale and Evidence Project Risk of Bias tool. RESULTS: Twenty-eight articles met inclusion criteria. Older age and higher comorbidity were strongly associated with higher-intensity testing. The evidence for provider and system-level covariates was weaker. However, there was strong evidence that a focus on primary care and away from preoperative clinic and cardiac consultations was associated with less testing and that interventions to reduce low-value testing can be successful. CONCLUSIONS: There is significant interprovider and interhospital variation in preoperative cardiac testing, the correlates of which are not well-defined. Further work should aim to better understand these factors.

Vancomycin Loading Doses and Nephrotoxicity on Medicine Teaching Services.

Background: Infectious Disease Society of America (IDSA) guidelines recommend the usage of a loading dose when using vancomycin for seriously ill patients. While the relationship between vancomycin and nephrotoxicity is the focus of many studies, few studies have examined the relationship between vancomycin loading doses and nephrotoxicity. Methods: We performed a retrospective cohort study examining vancomycin dosing for internal medicine teaching services' patients over the 2014-15 academic year at one academic medical center. We generated a list of all hospitalized patients aged 18-85 who received vancomycin and were admitted to a teaching service. Nephrotoxicity was determined by 7-day acute kidney injury (AKI) rate. Patients in the loading dose cohort were compared with those in the standard-dose cohort. Primary modeling used multivariable logistic regression with AKI as our outcome of interest. Results: Four hundred and thirty-eight patients were included for analysis. The loading dose (n = 365, 83%) and standard dosing (n = 73, 17%) cohorts were not significantly different regarding demographics, GFR, nephrotoxic drug exposure, total vancomycin received, trough levels, or comorbidities and were only significantly different regarding body mass index (BMI). The 7-day AKI rate was not significantly different between the two arms (6.3% in the standard dosing arm and 8.2% in the loading dose arm, p = 0.6). Conclusion: Few studies have examined the relationship between nephrotoxicity and vancomycin loading doses. The results of this study provide evidence that the use of loading doses is not significantly associated with increased 7-day AKI rate.

Wernicke-Korsakoff Syndrome in a Hunger Striker Despite Oral Thiamine Supplementation.

Case: We present the case of a 49-year-old woman who underwent a 237-day hunger strike on the streets of Pittsburgh, Pennsylvania. Despite medical supervision and appropriate micronutrient supplementation, including higher-than-recommended dosing of oral thiamine, the patient developed Wernicke's Encephalopathy and subsequent Korsakoff Syndrome. She is now permanently impaired. Introduction: Hunger strikers are subject to numerous sequelae of micronutrient deficiency. Among these are the paired conditions of Wernicke's Encephalopathy and Korsakoff Syndrome, conditions secondary to prolonged thiamine deficiency. Unfortunately, few published guidelines exist regarding the medical management of hunger strikers. Preventative dosing guidance is borrowed from what is recommended for prolonged malnourishment from eating disorders or chronic alcohol use. Available guidelines are rarely academic. Rather, they were created by governmental agencies for the management of hunger strikers in prison or similar states of detention or incarceration. There is an indirect body of evidence that oral thiamine supplementation is rarely protective against the sequelae of thiamine deficiency in hunger strikers. We discuss supplementation recommendations and the evidence for their failure in practice. We briefly explore the historical evidence for the anatomic and physiologic changes of prolonged starvation that potentially explain this treatment failure, and offer alternatives to standard supplementation. Conclusion: The current recommendations of the management of hunger strikers regarding the prevention of thiamine deficiency are inadequate, and rarely prevent the clinical sequelae. Alternate management strategies need to be both researched and empirically used, while that research is being carried out. Novel lipid-soluble thiamine derivatives have promise, but prophylactic intravenous/intramuscular thiamine should be explored as the current standard of care.

Influence of Familiarization and Competitive Level on the Reliability of Countermovement Vertical Jump Kinetic and Kinematic Variables.

Understanding typical variation of vertical jump (VJ) performance and confounding sources of its typical variability (i.e., familiarization and competitive level) is pertinent in the routine monitoring of athletes. We evaluated the presence of systematic error (learning effect) and nonuniformity of error (heteroscedasticity) across VJ performances of athletes that differ in competitive level and quantified the reliability of VJ kinetic and kinematic variables relative to the smallest worthwhile change (SWC). One hundred thirteen high school athletes, 30 college athletes, and 35 professional athletes completed repeat VJ trials. Average eccentric rate of force development (RFD), average concentric (CON) force, CON impulse, and jump height measurements were obtained from vertical ground reaction force (VGRF) data. Systematic error was assessed by evaluating changes in the mean of repeat trials. Heteroscedasticity was evaluated by plotting the difference score (trial 2 - trial 1) against the mean of the trials. Variability of jump variables was calculated as the typical error (TE) and coefficient of variation (%CV). No substantial systematic error (effect size range: -0.07 to 0.11) or heteroscedasticity was present for any of the VJ variables. Vertical jump can be performed without the need for familiarization trials, and the variability can be conveyed as either the raw TE or the %CV. Assessment of VGRF variables is an effective and reliable means of assessing VJ performance. Average CON force and CON impulse are highly reliable (%CV: 2.7% ×/÷ 1.10), although jump height was the only variable to display a %CV ≤SWC. Eccentric RFD is highly variable yet should not be discounted from VJ assessments on this factor alone because it may be sensitive to changes in response to training or fatigue that exceed the TE.

Applying measures of discriminatory accuracy to revisit traditional risk factors for being small for gestational age in Sweden: a national cross-sectional study.

OBJECTIVES: Small for gestational age (SGA) is considered as an indicator of intrauterine growth restriction, and multiple maternal and newborn characteristics have been identified as risk factors for SGA. This knowledge is mainly based on measures of average association (ie, OR) that quantify differences in average risk between exposed and unexposed groups. Nevertheless, average associations do not assess the discriminatory accuracy of the risk factors (ie, its ability to discriminate the babies who will develop SGA from those that will not). Therefore, applying measures of discriminatory accuracy rather than measures of association only, our study revisits known risk factors of SGA and discusses their role from a public health perspective. DESIGN: Cross-sectional study. We measured maternal (ie, smoking, hypertension, age, marital status, education) and delivery (ie, sex, gestational age, birth order) characteristics and performed logistic regression models to estimate both ORs and measures of discriminatory accuracy, like the area under the receiver operating characteristic curve (AU-ROC) and the net reclassification improvement. SETTING: Data were obtained from the Swedish Medical Birth Registry. PARTICIPANTS: Our sample included 731 989 babies born during 1987-1993. RESULTS: We replicated the expected associations. For instance, smoking (OR=2.57), having had a previous SGA baby (OR=5.48) and hypertension (OR=4.02) were strongly associated with SGA. However, they show a very small discriminatory accuracy (AU-ROC≈0.5). The discriminatory accuracy increased, but remained unsatisfactorily low (AU-ROC=0.6), when including all variables studied in the same model. CONCLUSIONS: Traditional risk factors for SGA alone or in combination have a low accuracy for discriminating babies with SGA from those without SGA. A proper understanding of these findings is of fundamental relevance to address future research and to design policymaking recommendations in a more informed way.

Countermovement jump height: gender and sport-specific differences in the force-time variables.

The goal of this study was to assess (a) the eccentric rate of force development, the concentric force, and selected time variables on vertical performance during countermovement jump, (b) the existence of gender differences in these variables, and (c) the sport-specific differences. The sample was composed of 189 males and 84 females, all elite athletes involved in college and professional sports (primarily football, basketball, baseball, and volleyball). The subjects performed a series of 6 countermovement jumps on a force plate (500 Hz). Average eccentric rate of force development (ECC-RFD), total time (TIME), eccentric time (ECC-T), Ratio between eccentric and total time (ECC-T:T) and average force (CON-F) were extracted from force-time curves and the vertical jumping performance, measured by impulse momentum. Results show that CON-F (r = 0.57; p < 0.001) and ECC-RFD (r = 0.52, p < 0.001) are strongly correlated with the jump height (JH), whereas the time variables are slightly and negatively correlated (r = -0.21-0.23, p < 0.01). Force variables differ between both sexes (p < 0.01), whereas time variables did not differ, showing a similar temporal structure. The best way to jump high is to increase CON-F and ECC-RFD thus minimizing the ECC-T. Principal component analysis (PCA) accounted for 76.8% of the JH variance and revealed that JH is predicted by a temporal and a force component. Furthermore, the PCA comparison made among athletes revealed sport-specific signatures: volleyball players revealed a temporal-prevailing profile, a weak-force with large ECC-T:T for basketball players and explosive and powerful profiles for football and baseball players.

Power athletes and distance training: physiological and biomechanical rationale for change.

The development of power lies at the foundation of all movement, especially athletic performance. Unfortunately, training programmes of athletes often seek to improve cardiovascular endurance through activities such as distance training that are detrimental for the performance of power athletes, rather than using other means of exercise. Performance decrements from continuous aerobic training can be a result of inappropriate neuromuscular adaptations, a catabolic hormonal profile, an increased risk for overtraining and an ineffective motor learning environment. However, long, sustained exercise continues to be employed at all levels of competition to obtain benefits that could be achieved more effectively through other forms of conditioning. While some advantageous effects of endurance training may occur, there are unequivocal drawbacks to distance training in the power athlete. There are many other types of conditioning that are more relevant to all anaerobic sports and will also avoid the negative consequences associated with distance training.

Overview of safety issues concerning the preparation and processing of soft-tissue allografts.

With the increasing use of allograft tissue and the recent infections found in patients undergoing surgical procedures, the current practices that prepare grafts for implantation must be examined. Initially, most tissue banks harvest allografts aseptically. There are many steps in the different techniques of preparation and processing of allograft tissue. Before allograft tissue is ready for clinical use, it undergoes specific disinfection methods, according to the individual tissue bank's specific process. Tissue banks use in-process bactericidal and virucidal steps via physical cleaning, chemical treatments, or application of irradiation to the allografts (or some combination thereof). Gamma irradiation may also be used as a terminal processing method to reach an assurance of sterility after the allograft has been packaged. Because of the allograft toxicity potential, the use of ethylene oxide as a final tissue sterilization measure is really nonexistent. The role of the Food and Drug Administration and American Association of Tissue Banks in allograft tissue handling is presented, as well as the new rules that regulate tissue banks and affect their processing methods.

Recent advances in glucosamine and chondroitin supplementation.

Glucosamine and chondroitin are alternative solutions to previous pharmaceutical options for the treatment of osteoarthritis. This article describes the mechanisms of action, pharmacokinetics, recent findings, and upcoming studies of these two natural remedies. The majority of studies on the mechanisms behind glucosamine and chondroitin have been performed in vitro or on animal models; however, the results have shown favorable effects on the balance between cartilage matrix synthesis and degradation. The pharmacokinetics of the three main forms of glucosamine were compared, and glucosamine hydrochloride displayed the greatest compound purity, despite the compounds having equal oral absorption rates of 90%. Chondroitin sulfate has been the principal clinical formulation with a slightly lower oral absorption of 70%. Clinical trials were evaluated based on two categories-radiographic changes and symptom improvement of pain and function. Although adverse effects of these two remedies were minor, the quality and labeled quantity of these relatively unregulated products must be considered. More randomized controlled studies on humans in vivo need to evaluate the efficacy, long-term effects, and quality of these compounds.