The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Nov 1979
Comparative StudyPulsatile perfusion versus conventional high-flow nonpulsatile perfusion for rapid core cooling and rewarming of infants for circulatory arrest in cardiac operation.
Thirty consecutive infants undergoing hypothermia and circulatory arrest for repair of ventricular septal defect, transposition of the great vessels, or atrioventricular canal defects were alternately selected for conventional high flow nonpulsatile perfusion or pulsatile perfusion during core cooling and rewarming. All received morphine anesthesia, 30 mg/kg of Solu-Medrol, and 10 to 15 mcg/kg of phentolamine. Those receiving nonpulsatile flow were perfused at a rate of 160 to 180 cc/kg/min with a roller pump and oxygenator with arterial pressure of 50 to 55 mm Hg. ⋯ The average postrewarming pH was 7.31 in the nonpulsatile group and 7.42 in the pulsatile group. Infants receiving pulsatile flow awakened more quickly, were more alert, and required less postoperative mechanical ventilation. We suggest that pulsatile perfusion for core cooling and rewarming of infants is safe and is more rapid and physiological than conventional high-flow nonpulsatile perfusion.
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J. Thorac. Cardiovasc. Surg. · Nov 1979
Measurement of ventilatory reserve as an indicator for early extubation after cardiac operation.
The decision to perform tracheal extubation in 44 patients who underwent cardiac operation was based on an assessment of mental alertness, recovery of muscle strength, hemodynamic stability, and adequacy of pulmonary gas exchange. No patients required reintubation. ⋯ By generally accepted criteria, these measurements suggested the need for continuing mechanical ventilation in 14 patients at the time mechanical ventilatory support was removed and in eight patients at the time of tracheal extubation. In this study, consideration of measurements of VC and PImax would have led to longer trachael intubation, especially in those patients who were extubated within 10 hours of the completion of anesthesia.
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J. Thorac. Cardiovasc. Surg. · Nov 1979
Measurement of postoperative cardiac output by thermodilution in pediatric and adult patients.
Serial cardiac output determinations were made by the thermodilution technique in 51 patients by means of a No. 2 Fr. thermistor catheter placed directly into the pulmonary artery at cardiac operation. Correlations were determined prospectively between thermodilution measurements of cardiac output and other commonly used indirect clinical parameters. ⋯ Statistically significant correlations were also seen between cardiac output and both the quality of the peripheral pulses and the duration of cardiopulmonary bypass, but no significant correlations were found between the measured cardiac outputs and other variables. This study confirms the necessity for direct measurement of cardiac output for its accurate assessment.
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J. Thorac. Cardiovasc. Surg. · Nov 1979
Plasma vasopressin levels and urinary flow during cardiopulmonary bypass in patients with valvular heart disease: effect of pulsatile flow.
The effect of pulsatile flow on plasma vasopressin levels during cardiopulmonary bypass (CPB) was studied in 20 patients undergoing open valve replacement. Routine bypass was used in 10 patients and the AVCO pulsatile bypass pump was utilized in the other 10. In Group I (nonpulsatile) during CPB, the vasopressin level was markedly elevated (3.1 +/- 2 to 80 +/- 22 pg/ml) as was urine flow (0.6 +/- 0.2 to 5.9 +/- 2 ml/min) and urine Na+ concentration (69 +/- 19 to 116 +/- 7 mEq/L). ⋯ These data suggest that CPB produces a marked vasopressin stress response which is beyond the physiological range for an antidiuretic effect on the kidney. At these levels vasopressin can exert a vasopressor effect to maintain resistance and affect renal blood flow, as well as producing an Na+ diuresis. The addition of pulsatile flow creates a more physiological situation attenuating the vasopressin response and producing a decrease in systemic resistance and a less pronounced Na+ diuresis.
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J. Thorac. Cardiovasc. Surg. · Jul 1979
Heparin administration during extracorporeal circulation: heparin rebound and postoperative bleeding.
The individual variations in heparin dose response and heparin activity decay have indicated limitations of the protocols based on body surface area and weight of the patients. In the present study the heparin levels and simpler clotting tests were monitored in a consecutive series of 71 patients undergoing standard cardiac operations. The clotting tests used were the Celite activated clotting time (Celite ACT) and the whole blood activated recalcification time (BART). ⋯ A significant difference was seen in the measured heparin levels (p less than 0.01, Celite ACT (p less than 0.01), and BART (p less than 0.01) in patients on Protocols I and II. Ten of the 24 patients on Protocol I and none on Protocol II showed heparin rebound phenomenon, and blood loss in patients on Protocol I was significantly greater than that in patients on Protocol II. The study clearly demonstrates that our protocol of heparin administration and control with simpler tests ensures safe hypocoagulation during ECC and efficient reversal at the end, with minimal postoperative blood loss.