[Long-term therapy with propofol has no impact on microcirculation in medical intensive care patients]. / Die Langzeitgabe von Propofol hat keinen Einfluss auf die Mikrozirkulation bei internistischen Intensivpatienten.

BACKGROUND: Microcirculation has become a major focus of research in critical care medicine due to its growing clinical relevance detecting changes in organ perfusion at an early stage. A negative impact of propofol infusion on microcirculation during short-term anesthesia was described recently. The influence of long-term sedation with propofol on microflow of critical care patients is still unclear. PATIENTS AND METHODS: Microflow was analyzed using sidestream darkfield microscopy of sublingual mucosa in 28 patients of whom eleven received continuous infusion of propofol. According to current guidelines, microflow was recorded digitally. Quantitative analysis was performed offline in a semiquantitative way (0: no flow; 1: intermittent flow; 2: sluggish flow; 3: continuous flow). RESULTS: Good microflow rates were detected in sublingual vessels (10-100 microm) in hemodynamically stable, medical intensive care patients. In the majority of cases, continuous flow profiles were recorded. There was no difference in flow rates between patients with and without propofol therapy. CONCLUSION: In hemodynamically stable intensive care patients, long-term therapy with propofol did not affect sublingual microflow in this small cohort. However, intensive care physicians should keep such possible interactions in mind avoiding administration of these substances in patients with manifested shock. The effects of propofol in hemodynamically impaired patients should be evaluated in further studies.

Evaluation of the sublingual microcirculation in cardiogenic shock.

OBJECTIVES: Orthogonal polarized spectral imaging- and sidestream darkfield-technique have enabled visual evaluation of the microcirculation. Different investigators described microcirculatory alterations, especially in surgical patients suffering from septic shock. We investigated the sublingual microcirculation in non-surgical patients admitted to our medical, intensive care unit (ICU). METHODS: In 24 severely ill (APACHE-II Score: 27.8+/-11.3), intubated patients admitted to our ICU the sublingual microcirculation was recorded with a handheld intravital microscope. Sublingual vessels were categorized according to their size (small: 10-25 microm; medium: 26-50 microm; large: 51-100 microm) and the flow in semiquantitative categories (0: no flow; 1: intermittent flow; 2: sluggish flow; 3: continuous flow). RESULTS: Patients with cardiogenic shock (n=7) had lower microflow compared with patients without cardiogenic shock (small p<0.001, medium p<0.001, large p=0.003). Several other diseases, including diabetes and arterial hypertension, age, gender, had no influence. In general, patients with a flow less than 3 in the small vessels showed higher arterial blood lactate levels (p=0.043) compared to continuous flow. CONCLUSIONS: A consequence of cardiogenic shock is the impairment of microcirculation with organ hypoperfusion. We observed that cardiac output is correlated to disturbance in microflow in the smallest vessels. On-line evaluation of microcirculation in vivo may be a valid tool for optimizing therapeutic measures in high risk patients. Additional online material may be found at: http://www.kim1.uniklinik-jena.de/Microcirculation.html.

Acute microflow changes after stop and restart of intra-aortic balloon pump in cardiogenic shock.

BACKGROUND: The intra-aortic balloon counter pulsation (IABP) is the most frequently used method of mechanical cardiac support in cardiogenic shock (CS). Microcirculatory impairment correlates with outcome in critically ill patients. We therefore investigated the acute influence of IABP therapy on sublingual microflow in patients with CS. METHODS: Sidestream darkfield intravitalmicroscopy was used in 13 patients with severe CS. The sublingual microvascular bed (10-100 microm) was examined according to current guidelines. We measured microflow in means of microvascular flow index at baseline and after intentional stop of IABP support. A computerized model was used for blinded off-line analysis. RESULTS: Microflow in vessels 10-50 microm in diameter was improved during IABP support (P < 0.001). Norepinephrine had a negative effect on the response to IABP related microflow improvement. Cardiac Perfusion Index (product of Cardiac Power index and microflow) correlated best with blood lactate levels. CONCLUSIONS: It was the aim of this study to evaluate the acute influence of IABP therapy on microflow in vivo. In this setting we found that IABP therapy improves sublingual microflow. Future studies should investigate Cardiac Perfusion Index under such conditions with respect to clinical decision making.

Effect of intra-aortic balloon pump support on microcirculation during high-risk percutaneous intervention.

BACKGROUND: Intra-aortic balloon counter-pulsation (IABP) is recommended for hemodynamic support in cardiogenic shock. In addition, it can be applied during high-risk percutaneous interventions (PCI). While IABP support improves microflow in cardiogenic shock, its effect in hemodynamically stable patients is still unclear. We, therefore, sought to evaluate the effect of IABP treatment on microflow in hemodynamically stable patients undergoing elective high-risk PCI. METHODS: In six patients with >50% left main stenosis, microflow was evaluated according to current guidelines, using side-stream dark-field microscopy, visualizing microcirculatory vessels without using fluorescent dyes. Microflow was analyzed separately for each vessel category (diameter: 10-25microm and 26-50microm), using a semiquantitative system (0= no flow; 1= intermittent flow; 2= sluggish flow; 3= continuous flow) by a trained investigator. Steady state recordings and additional recordings twenty seconds after discontinuation of the electively implanted IABP were acquired. RESULTS: Microflow in vessel categories 10-25microm and 26-50microm increased in this group of hemodynamically stable patients on use of IABP. Microflow decreased from 2.73 + or - 0.39 (p=0.052; 26-50microm: 2.88 + or - 0.20, p=0.008) to 2.22 + or - 0.23 (2.18 + or - 0.45) after stopping the IABP and increased to 2.90 + or - 0.14 (p=0.009; 2.85 + or - 0.28, p=0.009) after restart of the IABP. CONCLUSIONS: Circulatory support with IABP increases microcirculatory flow in the smallest vessels of the sublingual mucosa. Our data support the hypothesis that intra-aortic balloon counter-pulsation increases coronary and microvascular perfusion, thus, improving microcirculation even in hemodynamically stable patients. The use of IABP may increase safety of complex PCI and decrease the risk of deleterious complications.