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Clinical review: splanchnic ischaemia.

Jakob SM - Crit Care (2002)

Bottom Line: Total liver blood flow is believed to be relatively protected when gut blood flow decreases, because hepatic arterial flow increases when portal venous flow decreases (the hepatic arterial buffer response [HABR]).However, there is evidence that the HABR is diminished or even abolished during endotoxaemia and when gut blood flow becomes very low.Unfortunately, no drugs are yet available that increase total hepato-splanchnic blood flow selectively and to a clinically relevant extent.

View Article: PubMed Central - PubMed

Affiliation: Department of Intensive Care Medicine, University Hospital, Bern, Switzerland. stephan.jakob@insel.ch

ABSTRACT
Inadequate splanchnic perfusion is associated with increased morbidity and mortality, particularly if liver dysfunction coexists. Heart failure, increased intra-abdominal pressure, haemodialysis and the presence of obstructive sleep apnoea are among the multiple clinical conditions that are associated with impaired splanchnic perfusion in critically ill patients. Total liver blood flow is believed to be relatively protected when gut blood flow decreases, because hepatic arterial flow increases when portal venous flow decreases (the hepatic arterial buffer response [HABR]). However, there is evidence that the HABR is diminished or even abolished during endotoxaemia and when gut blood flow becomes very low. Unfortunately, no drugs are yet available that increase total hepato-splanchnic blood flow selectively and to a clinically relevant extent. The present review discusses old and new concepts of splanchnic vasoregulation from both experimental and clinical viewpoints. Recently published trials in this field are discussed.

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Lactate:pyruvate ratio in relation to lactate concentrations in 17 patients after cardiac surgery. Data points are pooled values from three different time points from arrival to the intensive care unit until extubation. (Adapted from [33].)
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Figure 1: Lactate:pyruvate ratio in relation to lactate concentrations in 17 patients after cardiac surgery. Data points are pooled values from three different time points from arrival to the intensive care unit until extubation. (Adapted from [33].)

Mentions: Blood flow may become insufficient after cardiac surgery because of increasing metabolic demands in combination with compromised myocardial function. We measured systemic, splanchnic and femoral blood flows, metabolism, and markers of the adequacy of tissue perfusion in 17 patients after elective cardiac surgery, from arrival in the intensive care unit until extubation [33]. Cardiac output and femoral blood flows increased by 12% and 28%, respectively, whereas the fraction of cardiac output distributed to the splanchnic region decreased by 20%. At the same time, splanchnic oxygen extraction increased by 16%. In certain patients splanchnic oxygen extraction was in the range at which signs of organ dysfunction or damage are likely to occur [34,35]. Hepatic venous lactate:pyruvate ratio was high after admission to the intensive care unit and decreased subsequently (Fig. 1). The high splanchnic lactate : pyruvate ratios at admission to the intensive care unit resulted from low pyruvate rather than high lactate levels, and are therefore unlikely to indicate anaerobic metabolism. On the other hand, only excessive anaerobic mesenteric metabolism or frank liver hypoxia will result in systemic hyperlactataemia because of the high lactate extraction capability of the liver. Initially high concentrations of glu-tathione transferase-α decreased during the postoperative period, and indocyanine green extraction was well preserved. It is likely that the observed increase in splanchnic oxygen extraction was sufficient to compensate for the lack of increase in blood flow and to maintain aerobic metabolism and cellular integrity in the splanchnic region in these patients with a normal cardiac reserve.


Clinical review: splanchnic ischaemia.

Jakob SM - Crit Care (2002)

Lactate:pyruvate ratio in relation to lactate concentrations in 17 patients after cardiac surgery. Data points are pooled values from three different time points from arrival to the intensive care unit until extubation. (Adapted from [33].)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC137310&req=5

Figure 1: Lactate:pyruvate ratio in relation to lactate concentrations in 17 patients after cardiac surgery. Data points are pooled values from three different time points from arrival to the intensive care unit until extubation. (Adapted from [33].)
Mentions: Blood flow may become insufficient after cardiac surgery because of increasing metabolic demands in combination with compromised myocardial function. We measured systemic, splanchnic and femoral blood flows, metabolism, and markers of the adequacy of tissue perfusion in 17 patients after elective cardiac surgery, from arrival in the intensive care unit until extubation [33]. Cardiac output and femoral blood flows increased by 12% and 28%, respectively, whereas the fraction of cardiac output distributed to the splanchnic region decreased by 20%. At the same time, splanchnic oxygen extraction increased by 16%. In certain patients splanchnic oxygen extraction was in the range at which signs of organ dysfunction or damage are likely to occur [34,35]. Hepatic venous lactate:pyruvate ratio was high after admission to the intensive care unit and decreased subsequently (Fig. 1). The high splanchnic lactate : pyruvate ratios at admission to the intensive care unit resulted from low pyruvate rather than high lactate levels, and are therefore unlikely to indicate anaerobic metabolism. On the other hand, only excessive anaerobic mesenteric metabolism or frank liver hypoxia will result in systemic hyperlactataemia because of the high lactate extraction capability of the liver. Initially high concentrations of glu-tathione transferase-α decreased during the postoperative period, and indocyanine green extraction was well preserved. It is likely that the observed increase in splanchnic oxygen extraction was sufficient to compensate for the lack of increase in blood flow and to maintain aerobic metabolism and cellular integrity in the splanchnic region in these patients with a normal cardiac reserve.

Bottom Line: Total liver blood flow is believed to be relatively protected when gut blood flow decreases, because hepatic arterial flow increases when portal venous flow decreases (the hepatic arterial buffer response [HABR]).However, there is evidence that the HABR is diminished or even abolished during endotoxaemia and when gut blood flow becomes very low.Unfortunately, no drugs are yet available that increase total hepato-splanchnic blood flow selectively and to a clinically relevant extent.

View Article: PubMed Central - PubMed

Affiliation: Department of Intensive Care Medicine, University Hospital, Bern, Switzerland. stephan.jakob@insel.ch

ABSTRACT
Inadequate splanchnic perfusion is associated with increased morbidity and mortality, particularly if liver dysfunction coexists. Heart failure, increased intra-abdominal pressure, haemodialysis and the presence of obstructive sleep apnoea are among the multiple clinical conditions that are associated with impaired splanchnic perfusion in critically ill patients. Total liver blood flow is believed to be relatively protected when gut blood flow decreases, because hepatic arterial flow increases when portal venous flow decreases (the hepatic arterial buffer response [HABR]). However, there is evidence that the HABR is diminished or even abolished during endotoxaemia and when gut blood flow becomes very low. Unfortunately, no drugs are yet available that increase total hepato-splanchnic blood flow selectively and to a clinically relevant extent. The present review discusses old and new concepts of splanchnic vasoregulation from both experimental and clinical viewpoints. Recently published trials in this field are discussed.

Show MeSH
Related in: MedlinePlus