Sevoflurane-mediated modulation of oxidative myocardial injury.

Introduction: Volatile anesthetics offer protection when administered throughout an ischemic injury. We examined how volatile anesthetics modulate the cardiac myocytic injury associated with hydrogen peroxide. Methods: Forty-eight Long-Evans rats were divided into four groups depending on the treatment: none (CONT), Glibenclamide (GLB); Sevoflurane (SEV); or GLB+SEV. Each group was further divided into two, one of which was exposed to hydrogen peroxide (H2O2). Oral GLB was administered 48 hours before myocardial isolation. All rats were anesthetized by intraperitoneal injection of Ketamine, and the hearts were harvested after heparinization. Cardiomyocytes were isolated using a combination of mechanical mincing and enzymatic digestion. After isolation, the aliquots of cells were exposed to H2O2 and FeSO4 for 30 minutes. The cell suspensions were then bubbled for 10 minutes with 100% oxygen and 1.5% SEV if appropriate. Apoptosis was detected by fluorescein-bound annexin-V (ANX-V), necrosis by propidium iodide, and ELISA assessed caspase-3 activity in all groups. Results: There was an increase in apoptosis, necrosis, and caspase-3 activity in the cells following exposure to hydrogen peroxide. SEV reduced the rate of cell necrosis and apoptosis. Pretreatment with GLB did not alter the effects of SEV. Similarly, caspase-3 activity did not change with GLB, although SEV administration reduced this enzymatic activity in response to hydrogen peroxide. Conclusion: In this oxidant injury model, we demonstrated that incubating isolated cardiomyocytes with SEV profoundly diminished H2O2-induced apoptotic and necrotic cells compared to their CONTs. These results support the hypothesis that KATP channels are not the sole mediators associated with anesthetic preconditioning.

Do Intrathecal Opioids Improve Surgical Outcomes After Coronary Artery Bypass Grafting? A Systematic Review and Analysis.

BACKGROUND: Intrathecal opioids have long been used as analgesia for intractable cancer pain or as part of spinal anesthesia during obstetric operations. More recently, they have been used preoperatively as a pain management adjuvant for open cardiac and thoracic procedures. OBJECTIVE: This study aims to analyze the impact of administering intrathecal opioids before cardiac and thoracic surgeries on postoperative pain and mechanical ventilation. STUDY DESIGN: Systematic review and meta-analysis. SETTING: University, School of Medicine, and several university-affiliated hospitals. METHODS: Five outcomes were studied, including the primary outcome of time to extubation, secondary outcomes of analgesia requirements at 24 and 48 hours, resting pain scores at 1 and 24 hours post-extubation, ICU length of stay in hours, and hospital length of stay in days. A search of multiple databases provided 28 studies reporting 4,000 total patients. Outcomes were measured using continuous mean difference with a 95% confidence interval, and the studies were examined for heterogeneity and sensitivity analysis. RESULTS: The primary outcome analysis suggested that time to extubation was 42 minutes shorter in the intrathecal opioid group (ranging from 82 to 1 minute, P = 0.04). There was also a decrease in postoperative analgesia requirements at both 24 hours (mean difference (MD) = -8.95 mg morphine equivalent doses (MED) [-9.4, -8.5], P < 0.001) and 48 hours (MD = -17.7 mg MED [-23.1, -12.4], P < 0.001) with I2 of 94% and 85% respectively, an improvement of pain scores at both 1 hour (MD = -2.24 [-3.16, -1.32], P < 0.001) and 24-hours (MD = -1.64 [-2.48, -0.80], P =< 0.001) I2 of 94% and 85%, no change in both ICU length of stay (MD = -0.27 hours [-0.55, 0.01], P = 0.06) I2 = 77% and hospital length of stay (MD = -0.30 days [-0.66, 0.06], P = 0.11) I2 = 32%. LIMITATIONS: The major limitation of this meta-analysis was the inconsistent dosages of intrathecal opioids utilized. Some used the same dose for each patient, while other studies used weight-based doses. The differences in the outcomes observed may then be a result of the different amounts of opioids administered rather than the technique itself. Another limitation was the inconsistent timing of reports for pain scores and postoperative analgesic requirements. Further studies were analyzed at the 2 time periods for both secondary outcomes, making it difficult to attribute the 2 effects solely to the intervention. CONCLUSIONS: We conclude that preoperative injection of intrathecal opioids is significantly associated with decreased time to extubation, decreased postoperative analgesia requirement, and improved pain scores. In controlled conditions with adequate staff education, this method of analgesia may make it possible to extubate the patients after the surgery in the operating room and fast-track their discharge from the hospital.

Energy loss index as a predictor of all-cause mortality after transcatheter aortic valve replacement: A long-term follow-up.

BACKGROUND: As transcatheter aortic valve replacement (TAVR) procedures become more widely available, there is a growing need to monitor and evaluate postoperative outcomes accurately. The energy loss index (ELI) of the ascending aorta has been commonly used to examine the agreement between the echocardiographic and Gorlin measurement of the aortic valve area. OBJECTIVES: This project aims to demonstrate a link between ELI values and mortality following implanted TAVR valves and determine an ELI cutoff value associated with post-TAVR events. METHOD: We retrospectively reviewed patients undergoing TAVR from 2012 to 2017. We calculated ELI values for patients immediately postoperative after a TAVR procedure. Using Receiver-Operator Characteristic and Cox Regression analyses, we identified a cutoff value to distinguish between "High ELI" (≥ 1.34) and "Low ELI" (< 1.34) patients. RESULTS: This study showed low ELI (hazard ratio, 2.30; 95% confidence interval 1.57-3.36, p < .001) as representative of patients with a high risk of mortality post-TAVR. Additionally, post-TAVR, ejection fraction increased by 3.6% (p < .001), and the aortic valve effective orifice area increased by 1.41 cm squared (p < .001) while the mean transvalvular gradient decreased by 32.8 mmHg (p < .001) and the peak transvalvular gradient decreased by 49.0 mmHg (p < .001). CONCLUSION: ELI is an additional prognostic factor that should be considered during risk assessment before TAVR. This study shows that patients with Low ELI had decreased cumulative survival post-TAVR. These patients almost had a fivefold increased risk of death following TAVR.

Volatile Anesthetics and Immunity.

Historically, volatile anesthetics have demonstrated interesting interactions with both the innate and adaptive immune systems. This review organizes these interactions into four phases: recognition, recruitment, response, and resolution. These phases represent a range of proinflammatory, inflammatory, and innate and adaptive immune regulatory responses. The interaction between volatile anesthetics and the immune system is discussed in the context of pathogenesis of infectious disease.