A comparison among portal lactate, intramucosal sigmoid Ph, and deltaCO2 (PaCO2 - regional Pco2) as indices of complications in patients undergoing abdominal aortic aneurysm surgery.

Our aim in this observational, prospective, noncontrolled study was to detect, in 29 patients who underwent abdominal aortic aneurysm (AAA) surgery, correlations between the incidence of postoperative organ failure and intraoperative changes in arterial and portal blood lactate; changes in intramucosal sigmoid pH (pHi); differences between sigmoid Pco(2) and arterial Pco(2) (DeltaCO(2)); and hemoglobin (Hb). Hb, arterial blood lactate concentrations, pHi, and DeltaCO(2) (air tonometry) were recorded at the start of anesthesia (T0), before aorta clamping (T1), 30 minutes after clamping (T2), and at the end of surgery (T3). Portal venous lactate concentrations were recorded at T1 and T2. Patients were stratified into two groups: group A patients had no postoperative organ failure, and group B patients had one or more organ failures. As compared with group A (n = 16), group B patients (n = 13) had a lower pHi value at T2 and T3 and a higher DeltaCO(2) at T3. A pHi value of <7.15 was a predictor of organ failure, with a sensitivity of 92.3%, a specificity of 68.8%, and positive and negative predictive values of 70.6% and 91.7%, respectively, whereas a DeltaCO(2) value of >28 mm Hg predicted later organ failure with a sensitivity of 92.3%, a specificity of 62.5%, and positive and negative predictive values of 66.6% and 90.9%, respectively. Portal venous lactate concentrations were larger in group B at T2 (P < 0.001), and an increase >or=5 g/dL predicted later postoperative organ failure with a sensitivity of 92.3%, a specificity of 100%, and positive and negative predictive values of 100% and 94.1%, respectively. The comparison of the receiving operator characteristic curves to test the discrimination of each variable and the logistic regression analysis revealed that the increase in portal lactate was the best predictor for the development of postoperative organ failure. Hb concentration was significantly smaller in group B at T0 (13.8 +/- 1.0 g/dL versus 12.2 +/- 2.2 g/dL) and T2 (10.9 +/- 1.2 g/dL versus 9.1 +/- 1.9 g/dL). In conclusion, both pHi and DeltaCO(2) are reasonably sensitive prognostic indices of organ failures after AAA surgery, but they are less specific and accurate than portal venous lactate.

[Fenoldopam and kidney function in a case of abdominal aortic pseudoaneurysm with supra-renal clamping in an emergency protocol]. / Fenoldopam e funzionalità renale in un caso di pseudo aneurisma dell'aorta addominale con clampaggio soprarenale in regime di urgenza.

The renal haematic flow decrease, the vasoconstriction and the local vascular resistance increase, associated with descending aortic cross-clamping, before the origin of renal arteries, can be contrasted by continuous infusion of fenoldopam, a dopamine analog with selective action on DA1-receptors. The renal effects of this molecule are renal plasmatic flow increase and local vascular resistance decrease, without important haemodynamic changes, with mild cardiovascular modification, even at high doses, in hypertensive and non hypertensive patients, also in normal volume condition and hypovolemic condition. This selective action at renal level allows the use of fenoldopam also in surgical emergencies, in patients with low cardiovascular function. The case report here presented demonstrated a beneficial renal effects of continuous infusion of fenoldopam and its easy to use, in emergency situations. These findings could be extrapolated for other patients or suggested for additional research.