Calcium Administration During Weaning From Cardiopulmonary Bypass: A Narrative Literature Review.

The search for safe and effective patient management strategies during weaning from cardiopulmonary bypass is ongoing; intravenous calcium is occasionally used as a first-line drug. The physiologic role of calcium suggests that it can support the function of the cardiovascular system during this critical period. Patients may be mildly hypocalcemic after cardiopulmonary bypass; however, this degree of hypocalcemia does not significantly impair the cardiovascular system. The transient beneficial effects of calcium administration (increase in arterial blood pressure, systemic vascular resistance, cardiac index, stroke volume, and coronary perfusion pressure) might be helpful in cases of moderate contractility reduction or vasoplegia. Nonetheless, effects on clinically relevant endpoints are unknown, and possible systemic side effects, such as transient reduction in internal mammary artery graft flow, attenuation of the effects of ß-sympathomimetics, "stone heart" phenomenon, and pancreatic cellular injury, may limit the use of calcium salts. Further studies are needed to expand the understanding of the effects of calcium administration on patient outcomes.

Volatile Anesthetics versus Total Intravenous Anesthesia for Cardiac Surgery.

BACKGROUND: Volatile (inhaled) anesthetic agents have cardioprotective effects, which might improve clinical outcomes in patients undergoing coronary-artery bypass grafting (CABG). METHODS: We conducted a pragmatic, multicenter, single-blind, controlled trial at 36 centers in 13 countries. Patients scheduled to undergo elective CABG were randomly assigned to an intraoperative anesthetic regimen that included a volatile anesthetic (desflurane, isoflurane, or sevoflurane) or to total intravenous anesthesia. The primary outcome was death from any cause at 1 year. RESULTS: A total of 5400 patients were randomly assigned: 2709 to the volatile anesthetics group and 2691 to the total intravenous anesthesia group. On-pump CABG was performed in 64% of patients, with a mean duration of cardiopulmonary bypass of 79 minutes. The two groups were similar with respect to demographic and clinical characteristics at baseline, the duration of cardiopulmonary bypass, and the number of grafts. At the time of the second interim analysis, the data and safety monitoring board advised that the trial should be stopped for futility. No significant difference between the groups with respect to deaths from any cause was seen at 1 year (2.8% in the volatile anesthetics group and 3.0% in the total intravenous anesthesia group; relative risk, 0.94; 95% confidence interval [CI], 0.69 to 1.29; P = 0.71), with data available for 5353 patients (99.1%), or at 30 days (1.4% and 1.3%, respectively; relative risk, 1.11; 95% CI, 0.70 to 1.76), with data available for 5398 patients (99.9%). There were no significant differences between the groups in any of the secondary outcomes or in the incidence of prespecified adverse events, including myocardial infarction. CONCLUSIONS: Among patients undergoing elective CABG, anesthesia with a volatile agent did not result in significantly fewer deaths at 1 year than total intravenous anesthesia. (Funded by the Italian Ministry of Health; MYRIAD ClinicalTrials.gov number, NCT02105610.).

Remote ischaemic preconditioning does not protect the heart in patients undergoing coronary artery bypass grafting.

Remote ischaemic preconditioning (RIPC) gained attention as a possibility to reduce myocardial injury after a subsequent sustained episode of myocardial ischaemia. This prospective randomized study was carried out to assess whether RIPC reduces myocardial injury in coronary artery bypass grafting patients. Eighty patients were assigned to remote preconditioning or control treatment. Ischaemic preconditioning was induced by three 5-min cycles of upper limb ischaemia and reperfusion after anaesthesia induction. Haemodynamic and markers of myocardial damage were analysed preoperatively and over 48 h postoperatively. The cardiac index was higher immediately after remote preconditioning in the main group. There were no differences in other haemodynamic, troponin I and creatine kinase-MB concentrations at any time point between groups. Thus, short-term remote preconditioning improves haemodynamics and does not reduce myocardial injury after coronary artery bypass surgery. Further study of high-risk patients may be needed to fully evaluate the clinical effect of RIPC.