Harikesh Subramanian

Background Intraoperative hypotension burden not equally distributed during various periods of a general anesthetic. Post-induction hypotension usually has an iatrogenic cause and is related to the combination of drug doses used for induction of anesthesia. Predicting post-induction blood pressures, prior to induction, may inform anesthesiologists on the most judicious selection of anesthetic drugs and dosages. Our objective was to explore patterns of post-induction hypotension, apply machine learning (ML) to predict the mean blood pressure (MBP) immediately after induction, and develop a prototype of a clinical tool that can implement the ML model. Materials and Methods We extracted data from preoperative and intraoperative anesthetic episodes over an 8-year period at the University of Pittsburgh Medical Center. The dataset consisted of 93,037 anesthetic episodes, which was partitioned into training, validation, and test sets. Preoperative and pre-induction predictor variables included demographics, comorbidities, laboratory test values, pre-induction MBP, and administrations of induction drugs. The target consisted of 15 minutes of MBP values immediately after induction. Results The best-performing model was extreme-gradient boosted trees (XGB), with an R-squared value of 0.31 and a mean absolute error of 11.96, which is a moderately good performance. The performance of the model decreased over each minute post-induction. Conclusion ML modeling to predict post-induction MBP is feasible, and a clinical tool that incorporates ML can potentially aid in preventing hypotension in the operating room.

Background/Objectives: Hypo-hydration is a major health concern that affects performance and is associated with increasing morbidity and growing health care costs. There is an emerging interest in optimizing hydration and identifying how factors such as ingestion rate and beverage composition affect hydration. This study examined three beverages with varying ingestion rates and measured markers of hydration. Methods: Thirty healthy, active participants between the ages of 18 and 45 years were given three different beverages on three separate days. The beverages were of identical volumes (1 L), but differed in the rate of ingestion, carbohydrate content and electrolyte content. Beverage 1 and water alone were both consumed at a metered rate of one liter over four hours, whereas Beverage 2 was used as a positive control and was consumed at a bolus rate of one liter in 30 min. Results: After six hours, Beverage 1 significantly improved markers of hydration compared to water alone or Beverage 2. Beverage 1 decreased cumulative urine output vs. water alone by 32% (absolute difference −0.33 L; CI ± −0.16 to −0.51) and vs. Beverage 2 by 26% (absolute difference −0.26 L; CI ± −0.13 to −0.38). Beverage 1 increased the beverage hydration index vs. water alone by 64% (absolute difference +0.64 L; CI ± 0.36 to 0.92) and vs. Beverage 2 by 48% (absolute difference +0.53 L; CI ± 0.30 to 0.76). Conclusions: Beverage 1 is superior to water alone at improving hydration when it is ingested at similar rates. Moreover, metered ingestion of Beverage 1 improved hydration compared to a bolus ingestion of Beverage 2, this could be due to the dissimilar ingestion rates and/or beverage composition.

The concept of “pre-habilitation” comprises screening for and identification of pre-existing disorders followed by medical optimization. This is performed for many types of surgeries, but may have profound impacts on outcomes, particularly in cardiac surgery given the multiple comorbidities typically carried by these patients. Components of pre-habilitation include direct medical intervention by preoperative specialists as well as significant care coordination and shared decision-making. In this second part of a two-part review, the authors describe existing evidence to support the optimization of various preoperative problems and present a few institutional protocols utilized at out center for cardiac presurgical care. This second installment will focus on alcohol and smoking cessation and the management of frailty, malnutrition, respiratory disease, and depression.

The concept of “prehabilitation” consists of screening for and identification of pre-existing disorders followed by medical optimization. This is performed for many types of surgery, but may have profound impacts on outcomes particularly in cardiac surgery given the multiple comorbidities typically carried by these patients. Components of prehabilitation include direct medical intervention by preoperative specialists as well as significant care coordination and shared decision making. In this two-part review, the authors describe existing evidence to support the optimization of various preoperative problems and present a few institutional protocols utilized by our center for cardiac presurgical care. This first installment will focus on the management of anemia, obesity, sleep apnea, diabetes, and cardiac rehabilitation prior to surgery. The second will focus on frailty, malnutrition, respiratory disease, alcohol and smoking cessation, and depression.

Heart failure (HF) remains a leading cause of morbidity, hospitalization, and mortality worldwide. Advancement of mechanical circulatory support technology has led to the use of continuous-flow left ventricular assist devices (LVADs), reducing hospitalizations, and improving quality of life and outcomes in advanced HF. Recent studies have highlighted how metabolic and endocrine dysfunction may be a consequence of, or associated with, HF, and may represent a novel (still neglected) therapeutic target in the treatment of HF. On the other hand, it is not clear whether LVAD support, may impact the outcome by also improving organ perfusion as well as improving the neuro-hormonal state of the patients, reducing the endocrine dysfunction. Moreover, endocrine function is likely a major determinant of human homeostasis, and is a key issue in the recovery from critical illness. Care of the endocrine function may contribute to improving cardiac contractility, immune function, as well as infection control, and rehabilitation during and after a LVAD placement. In this review, data on endocrine challenges in patients carrying an LVAD are gathered to highlight pathophysiological states relevant to this setting of patients, and to summarize the current therapeutic suggestions in the treatment of thyroid dysfunction, and vitamin D, erythropoietin and testosterone administration.