The difference in CO2 tension between venous and arterial blood (delta PCO2) increases in low-flow states. Therefore, delta PCO2 has been suggested as an additional variable in the monitoring of ...perfusion. We measured CO2 tensions in arterial, mixed venous, hepatic venous, and femoral venous blood in 42 postoperative cardiac surgery patients. Splanchnic and leg blood flow was measured with dye dilution. Forty-three preoperative abdominal surgery patients served as controls. Systemic and femoral delta PCO2 was increased in cardiac patients, whereas there was no difference in splanchnic delta PCO2 between the groups. In cardiac patients, systemic delta PCO2 correlated well with both splanchnic and femoral delta PCO2 (r2 = .74 and r2 = .56, respectively). Femoral delta PCO2 was higher than splanchnic delta PCO2 (1.27 +/- .44 kPa versus .66 +/- .41; p < .001) after cardiac surgery, but not in the control group. The correlation between delta PCO2 and respective blood flow was weak in the whole body, the splanchnic region, and the leg. When splanchnic blood flow was low, systemic and splanchnic delta PCO2 varied widely. In the cardiac patients with an increased systemic delta PCO2 (> .93 kPa), systemic and regional blood flow was low, but there were no differences in systemic or regional oxygen consumption or lactate levels. After cardiac surgery, high systemic delta PCO2 is associated with marginal systemic and regional perfusion. The adequacy of regional blood flow cannot be assessed on the basis of the systemic delta PCO2.
The ever-growing market pressure and complex products demand high quality work and effectiveness from software practitioners. This relates also for the methods and tools they use for the development ...of software-intensive systems. Validation and verification (V&V) are the cornerstones of the overall quality of a system. By performing efficient V&V activities to detect defects during the early phases of development, the developers are able to save time and effort required for fixing them. Tool support is available for all types of V&V activities, especially testing, model checking, syntactic verification, and inspection. In distributed development the role of tools is even more relevant than in single-site development, and tool integration is often imperative for ensuring the effectiveness of work. In this paper, we discuss how a tool integration framework was extended to support early V&V activities via continuous integrations. We find that integrating early V& V supporting tools is feasible and useful, and makes a tool integration framework even more beneficial.
Sixty-two patients (34 men and 28 women) aged 19-64 years, half of whom had familial hypercholesterolemia, treated initially for 18 weeks with lovastatin alone were randomly allocated either to ...lovastatin (L) and cholestyramine (16 g/day) or lovastatin and guar gum (L + GG 20 g/day) treatment for 18 additional weeks to compare the hypocholesterolemic effects of these two combination therapies. The patients were selected for this study from a larger study of patients (n = 120) with severe hypercholesterolemia serum total cholesterol (serum Chol) 6.5-16.3 mM before treatment, and only those patients in whom serum Chol after lovastatin alone (dose 80 mg/day) remained greater than or equal to 5.2 mM were eligible for evaluation of combination therapies. Serum Chol decreased from 10.6 +/- 1.6 to 5.9 +/- 1.3 mM (mean +/- SD) (p less than 0.001) and low-density lipoprotein cholesterol (LDL Chol) from 8.5 +/- 1.8 to 4.1 +/- 1 mM (p less than 0.001) in patients treated with L + GG (values before the beginning of lovastatin and at the end of the combination therapy). The respective changes were from 10.9 +/- 2.2 to 5.5 +/- 1.2 mM (p less than 0.001) and from 8.7 +/- 2.3 to 3.5 +/- 1.2 mM (p less than 0.001) in patients treated with lovastatin and cholestyramine (L + C). At the end of the study, both serum Chol (p less than 0.005) and LDL Chol (p less than 0.01) were significantly lower with L + C than with L + GG.
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