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Objective: The aim of this study was to compare a standard insulin protocol with a computer-guided glucose management system to determine which method achieves tighter glucose control., Design: A prospective, randomized trial., Setting: A cardiothoracic intensive care unit (ICU) in a large academic medical center., Participants: Forty patients with diabetes mellitus who were scheduled for cardiac surgery., Interventions: After induction of anesthesia and for the first 9 hours in the ICU, each subject received a standardized infusion of a 10% glucose solution at a rate of 1.0 mL/kg/h (ideal body weight). The subjects were then randomized to have their glucose controlled by either a paper-based insulin protocol or by a computer-guided glucose management system (CG). The desired range for blood glucose was set between 90 and 150 mg/dL., Measurements and Main Results: There were no differences between groups in baseline characteristics. Patients in the CG group spent more time in the desired range during both the intraoperative phase (49% v 27%, p = 0.001) and the ICU phase (84% v 60%, p < 0.0001). There were no statistical differences between groups in the number of hypoglycemia episodes., Conclusions: The computer-guided glucose management system achieved tighter blood glucose control than a standard paper-based protocol in diabetic patients undergoing cardiac surgery. However, the low proportion of blood glucose recordings within the desired range in both groups during the intraoperative period reflects the challenges associated with achieving normoglycemia during cardiac surgery.

Objective: The aim of this study was to examine the effects of small changes in PaCO(2) on hemodynamic parameters after uncomplicated heart surgery with cardiopulmonary bypass., Design: This was a prospective, randomized crossover study., Setting: A large academic medical center., Participants: Twenty-four subjects who were scheduled for elective cardiac surgery were enrolled in this study., Interventions: Each subject underwent the normal procedures that are associated with cardiac surgery. General anesthesia, including muscle relaxation, were continued in the immediate postoperative period. Measured tidal volumes and minute ventilation were kept constant for the duration of the study. Target PaCO(2) concentrations of 30, 40, and 50 mmHg were achieved by adding varying amounts of exogenous CO(2) gas to the inhaled oxygen. Various measurements were made at each target PaCO(2), including cardiac index, mixed venous oxygen saturation, blood pressure, heart rate, and pulmonary artery pressure., Measurements and Main Results: Twenty-four patients were enrolled. Seven were withdrawn before commencement of the study. The cardiac index increased when the PaCO(2) was increased from 30 to 40 mmHg (p < 0.001) and remained unchanged between 40 and 50 mmHg. Mixed venous oxygen saturation increased (p < 0.001) with elevations in PaCO(2) up to 50 mmHg and decreased again when the PaCO(2) was returned to 30 mmHg. The blood pressure decreased (p < 0.001) with increasing PaCO(2). The pulmonary pressure increased (p < 0.001) with elevations in PaCO(2). No patient became hemodynamically unstable or had any arrhythmias., Conclusion: The findings of this study suggest that unless there is a specific contraindication to mild hypercapnia, such as pulmonary hypertension or hemodynamic instability, concerns about mild respiratory acidosis should not prevent weaning of sedation and mechanical ventilation after uncomplicated heart surgery.