Effect of Perioperative Goal-Directed Hemodynamic Resuscitation Therapy on Outcomes Following Cardiac Surgery: A Randomized Clinical Trial and Systematic Review.

OBJECTIVES: To evaluate the effects of goal-directed therapy on outcomes in high-risk patients undergoing cardiac surgery. DESIGN: A prospective randomized controlled trial and an updated metaanalysis of randomized trials published from inception up to May 1, 2015. SETTING: Surgical ICU within a tertiary referral university-affiliated teaching hospital. PATIENTS: One hundred twenty-six high-risk patients undergoing coronary artery bypass surgery or valve repair. INTERVENTIONS: Patients were randomized to a cardiac output-guided hemodynamic therapy algorithm (goal-directed therapy group, n = 62) or to usual care (n = 64). In the goal-directed therapy arm, a cardiac index of greater than 3 L/min/m was targeted with IV fluids, inotropes, and RBC transfusion starting from cardiopulmonary bypass and ending 8 hours after arrival to the ICU. MEASUREMENTS AND MAIN RESULTS: The primary outcome was a composite endpoint of 30-day mortality and major postoperative complications. Patients from the goal-directed therapy group received a greater median (interquartile range) volume of IV fluids than the usual care group (1,000 [625-1,500] vs 500 [500-1,000] mL; p < 0.001], with no differences in the administration of either inotropes or RBC transfusions. The primary outcome was reduced in the goal-directed therapy group (27.4% vs 45.3%; p = 0.037). The goal-directed therapy group had a lower occurrence rate of infection (12.9% vs 29.7%; p = 0.002) and low cardiac output syndrome (6.5% vs 26.6%; p = 0.002). We also observed lower ICU cumulative dosage of dobutamine (12 vs 19 mg/kg; p = 0.003) and a shorter ICU (3 [3-4] vs 5 [4-7] d; p < 0.001) and hospital length of stay (9 [8-16] vs 12 [9-22] d; p = 0.049) in the goal-directed therapy compared with the usual care group. There were no differences in 30-day mortality rates (4.8% vs 9.4%, respectively; p = 0.492). The metaanalysis identified six trials and showed that, when compared with standard treatment, goal-directed therapy reduced the overall rate of complications (goal-directed therapy, 47/410 [11%] vs usual care, 92/415 [22%]; odds ratio, 0.40 [95% CI, 0.26-0.63]; p < 0.0001) and decreased the hospital length of stay (mean difference, -5.44 d; 95% CI, -9.28 to -1.60; p = 0.006) with no difference in postoperative mortality: 9 of 410 (2.2%) versus 15 of 415 (3.6%), odds ratio, 0.61 (95% CI, 0.26-1.47), and p = 0.27. CONCLUSIONS: Goal-directed therapy using fluids, inotropes, and blood transfusion reduced 30-day major complications in high-risk patients undergoing cardiac surgery.

Comparison of pH-stat versus Alpha-stat during hypothermic cardiopulmonary bypass in the prevention and control of acidosis in cardiac surgery.

OBJECTIVES: To compare the effects of blood-gas management using either alpha-stat (temperature-uncorrected blood-gas management) or pH-stat (temperature-corrected blood-gas management) strategies, 30 patients undergoing coronary artery bypass surgery allocated randomly to either one of the approaches were studied. Acid-base balance, tissue oxygenation, and biochemical parameters were measured at distinct times: before bypass, after 15 min of hypothermia at 32 degrees C, after 45 min of hypothermia at 32 degrees C, after 15 min of rewarming at 37 degrees C, and 45 min after the end of bypass in normothermic conditions. RESULTS: The groups were similar with regard to physical characteristics, physiological parameters, and bypass time. In the pH-stat group, CO2 administered with the aim of correcting pH for the patients hypothermic temperature caused a significant increase in temperature-uncorrected PaCO2 and a decrease in arterial temperature-uncorrected pH at 45 min. During the rewarming period and following bypass, the pH was lower and PaCO2 higher in the pH-stat group (P < 0.001). CONCLUSION: It was found that during the rewarming period and following bypass, the resulting acidosis caused by the procedure was less in the alpha-stat group. It was found that there were no difference between the two groups, with regard to tissue perfusion, as is seen by the tissue oxygenation parameters and lactic acid concentration.

Decreased 2,3-diphosphoglycerate concentration in low cardiac output patients and its influence on the determination of in vivo p50.

We investigated whether 2,3-diphosphoglycerate (2,3-DPG) is altered in patients with low cardiac output and the influence of its concentration on the calculation of in vivo P(50). Biochemical and blood gas analysis were performed along with the measurement of cardiac output and body temperature in 13 patients submitted to cardiopulmonary bypass surgeries without the use of donor blood. In vivo P(50) was calculated using the measured (P(50m)) and the estimated 2,3-DPG (P(50e)). 2,3-DPG concentration was lower in these patients when compared to the values obtained in normal volunteers (6.9 +/- 2.2 vs. 11.9 +/- 2.4 microm/gHb). P(50m) was lower than P(50e) (21.6 +/- 1.1 vs. 30.1 +/- 1.2 mm Hg) at all time points. Our data show that in patients with low cardiac output, 2,3-DPG concentration is reduced. Therefore, in these patients, the use of standard values for this variable may introduce an error in the calculation of in vivo P(50).