[Indocyanine green plasma disappearance rate. Marker of partial hepato-splanchnic ischemia]. / Indozyaningrün-Plasmaverschwinderate. Marker einer partiellen Ischämie im Hepatosplanchnikustrakt.

Indocyanine green (ICG) is nearly exclusively eliminated from the blood by the liver and the ICG plasma disappearance rate (ICG-PDR) enables assessment of liver blood flow and function. The ICG-PDR which nowadays can be measured non-invasively by a transcutaneous system enables bedside and "on-line" regional monitoring in critically ill patients. So far, only complete lack of ICG-PDR as a sign of non-existing perfusion during liver transplantation has been reported. We describe two patients who developed mesenteric ischemia accompanied by an inadequate increase after revascularisation and an acute drop in the ICG-PDR. In both cases, a computed tomography scan was performed and confirmed an acute abdominal ischemia as indicated by ICG-PDR. Both patients suffered from occlusion of the truncus coeliacus while hepato-splanchnic perfusion via the A. mesenterica superior and the V. portae was maintained. ICG-PDR may be helpful for early detection of hepato-splanchnic ischemia and enables rapid and sufficient initiation of diagnostic and therapeutic procedures. In conclusion, ICG-PDR may be regarded as a clinically attractive bedside monitoring tool for early and reliable detection of partial ischemia in the hepato-splanchnic tract.

Acid-base balance and substitution fluid during continuous hemofiltration.

Critically ill patients with acute renal failure usually present with an unstable acid-base balance, often leading to cardiovascular complications and multi-organ failure. Therefore, to prevent metabolic acidosis, acid-base balance must be normalized and maintained; these patients are primarily treated with continuous hemofiltration techniques using different replacement fluids to influence the acid-base values. Dialysate solutions can be an acetate-based, lactate-based, citrate-based or bicarbonate-based buffer. This article discusses the strengths and weaknesses of each type of hemofiltration replacement fluid.

The use of different buffers during continuous hemofiltration in critically ill patients with acute renal failure.

OBJECTIVE: To determine the impact of different hemofiltration (HF) replacement fluids on the acid-base status and cardiovascular hemodynamics in patients with acute renal failure (ARF) and continuous veno-venous hemofiltration (CVVH). DESIGN: Prospective, cohort study. SETTING: Intensive Care Unit of the Heinrich Heine University Hospital, Düsseldorf, Germany. SUBJECT AND METHODS: One hundred and thirty-two critically ill patients with acute renal failure and continuous veno-venous HF were studied. Fifty-two patients were subjected to lactate-based (group 1), and 32 to acetate-based hemofiltration (group 2) while 48 (group 3) were treated with bicarbonate-based buffer hemofiltration fluid. Fifty-seven had a septic, and 75 a cardiovascular, origin of the ARF. Creatinine, blood urea nitrogen (BUN), serum bicarbonate, arterial pH, lactate and Apache II scores were noted daily. MAIN RESULTS: The mean CVVH duration was 9.8 +/- 8.1 days, mortality was 65%. No difference was present between the groups under investigation with regard to the main clinical parameters. Lactate- and bicarbonate-based hemofiltration led to significantly higher serum bicarbonate and arterial pH values as compared to the acetate-based hemofiltration. Serum bicarbonate values at 48 h after the initiation of CVVH treatment were 25.7 +/- 3.8 mmol/l (p < 0.001) in group 1, 20.6 +/- 3.1 mmol/l in group 2 and 23.3 +/- 3.9 mmol/l (p < 0.001) in group 3. While a lack of increase in serum bicarbonate and arterial pH was correlated to poor prognosis in lactate- and bicarbonate-based hemofiltration, no such observation was made in acetate-based hemofiltration. Cardiovascular hemodynamics were superior in patients treated with lactate- and bicarbonate-based buffer solution as compared to those treated with acetate-based buffer solution. CONCLUSIONS: The degree of correction of acidosis during hemofiltration was determined by patient outcome in patients treated with lactate- and bicarbonate-based buffer solutions, but not in patients receiving acetate-buffered solution. Bicarbonate and lactate-based buffer solutions were found to be superior to acetate-based replacement fluid.