Pre-operatieve hemodynamische optimalisatie door middel van het verhogen van het zuurstof-aanbod bij hoog-risico-chirurgie

Preoperative hemodynamic optimization by means of augmenting oxygen delivery is an attractive concept to reduce morbidity after major surgery. Several prospective controlled randomised studies demonstrate a positive effect on mortality and morbidity. However, it is still uncertain which patients will benefit most from such a policy and by what means preoperative optimization is best achieved. We believe that the target of optimization should not be a prefixed value for oxygen delivery, but rather one individualized for each patient ("tune-up"). In this regard, a better preoperative fluid-status appears to be most essential

Application of liquid chromatography-mass spectrometry to measure the concentrations and study the synthesis of short chain fatty acids following stable isotope infusions

A new method involving zinc sulphate deproteinization was developed to study short chain fatty acids (SCFA) production in the colon and subsequent occurrence of SCFA in blood. SCFA were baseline separated in a 30 min cycle using ion-exclusion chromatography and detected by mass spectrometry. Concentrations could be measured down to 10 μM and isotopomeric distributions could be assessed, enabling the conduction of tracer studies to study changes in SCFA synthesis. The applicability of the method was tested in an extensively characterized pig model yielding portal SCFA concentrations ranging from 70 μM (butyric acid) to 150 μM (propionic acid) to 440 μM (acetic acid) prior to butyrate tracer infusion, reaching butyric acid isotopic steady state within 2 h. © 2007 Elsevier B.V. All rights reserved