Classically septic shock treatment takes into consideration only systemic parameters but failure in retaining arteriolar blood flow and functional capillary density (FCD) during sepsis worsens the outcome. Thus, we have investigated the effects of vigorous volume resuscitation (VR), two doses of dopamine and their combination upon the microcirculation during endotoxemia to evaluate if improvement on FCD and arteriolar blood flow would increase survival time. Sixty-seven adult male hamsters were studied using the window chamber model. Animals were randomized 1 h after the intravenous injection of 1 mg/kg of E. coli lipopolysaccharide (LPS) in LPS, no treatment; LPS/dopamine 3.0 g/kg/min; LPS/dopamine 7.5 g/kg/min; LPS/VR 20 ml/kg in 30 min followed by 20 ml/kg/h of saline; LPS/VR/Dopa 3.0, 20 ml/kg in 30 min followed by 20 ml/kg/h of saline associated to dopamine 3.0 g/kg/min; LPS/VR/Dopa 7.5 (n = 6), 20 ml/kg in 30 min followed by 20 ml/kg/h of saline associated to dopamine 7.5 g/kg/min and compared them to a Control group, no LPS. When present, treatment lasted 5 h. VR improved FCD and arteriolar blood flow score while dopamine did not. In conclusion, (1) improvement of FCD and arteriolar blood flow improved survival time; (2) VR recovered FCD and arteriolar blood flow and (3) in combination to VR, both dopamine doses reduced tissue perfusion (its low dose yielded the worst result).

Nailfold videocapillaroscopy was performed in 2 groups of subjects: 14 healthy volunteers (C) and 15 patients with primary Sjögren's syndrome (PSS). This was a controlled clinical trial, matched by age and sex. The aims of this study were to evaluate (1) functional capillary density (number of capillaries with flowing red blood cells per mm 2 , FCD); (2) capillary red blood cell velocity at rest (RBV), maximum capillary red blood cell velocity (RBVmax) after 1 minute ischemia, and the time to reach it (TRBVmax), taking into account the presence or absence of Raynaud's phenomenon (RP) in the analysis; (3) nailfold capillary morphology; and (4) afferent (AFD), apical (APD), and efferent (EFD) capillary diameters. The mean values obtained for controls versus patients, respectively, were (mean ± SD): FCD (per mm 2 ) 8.0 ±1.6 and 10.1 ±3.6; RBV (mm/s) 0.9 ±0.4 and 0.7 ±0.2; RBVmax (mm/s) 1.7 ±0.9 and 1.3 ±0.3; TRBVmax (s) 4.5 ±0.8 and 5.8 ±1.6 (p=0.02); and TRBVmax (s) in patients with RP=6.7 ±1.6 and without RP=5.6 ±1.6 (p=0.52). The correlation between RBV and RBVmax for each group, using the Pearson's coefficient, was significant only for the control group (p = 0.007), estimated correlation coefficient = 0.68. Controls and patients showed, in the majority of fields examined, normal morphologic patterns of capillaries. The capillary diameters were AFD (µm) 10.8 ±1.5 and 11.3 ±1.8; APD (µm) 16.3 ±2.4 and 16.8 ±2.9; and EFD (µm) 12.3 ±1.4 and 13.7 ±1.9. These results indicate that these patients have longer time to reach RBVmax, suggesting an impairment of the reactive hyperemia response, which could correlate with clinical features of the disease, ie, abnormal macrovascular and microvascular reactivity.

OBJECTIVE: Apart from its anticoagulant properties, heparin has vasodilator and anti-inflammatory effects that could assist in the reversal of septic microcirculatory changes. This paper investigates the effects of heparin on endotoxemia-related microcirculatory changes and compares them to those observed with the use of recombinant human activated protein C. METHODS: After skinfold chamber implantation procedures and endotoxemia induction by intravenous Escherichia coli lipopolysaccharide administration (2 mg.kg 21), male golden Syrian hamsters were treated with intravenous unfractionated heparin (0.2 mg.kg 21). Intravital microscopy of skinfold chamber preparations allowed quantitative analysis of microvascular variables and venular leukocyte rolling and adhesion. Macrohemodynamic parameters were also analyzed. Endotoxemic hamsters treated with recombinant human activated protein C and non-treated animals served as controls. RESULTS: Heparin decreased lipopolysaccharide-induced leukocyte rolling and arteriolar vasoconstriction; it also increased survival when compared with non-treated animals, while recombinant human activated protein C decreased leukocyte adhesion. Administration of heparin plus recombinant human activated protein C was associated with a significant attenuation of lipopolysaccharide-induced capillary perfusion deficits. CONCLUSIONS: Heparin yields protective effects on endotoxemic animals' microcirculation. Those benefits were potentiated when heparin was administered in conjunction with recombinant human activated protein C.

OBJECTIVEThis study investigated the effects of buflomedil and pentoxifylline, both of which are used in reconstructive surgery of hamster skin flap microcirculation, and evaluated the skin flap survival rate by orthogonal polarization spectral imaging.METHODTwenty-four adult male Syrian golden hamsters were divided into three groups: a control (C, 0.1 ml 0.9% saline), buflomedil (B, 3 mg/kg/day), and pentoxifylline group (P, 14.5 mg/kg/day). Treatments administered intraperitoneally were initiated 1 hour before skin flap preparation and continued for 7 days post-operatively at 12-hour intervals. Preparations (skin flaps) were divided into 12 fields, which were organized into six bands. Functional capillary density (FCD, in mm/mm2), distance from the skin flap base to blood flow cessation (Distwith flow, in cm), percentage of viable skin (VA, in%), and qualitative analysis of blood flow by orthogonal polarization spectral imaging were performed at 1 and 24 hours and on the seventh post-operative day.RESULTBands IV, V, and VI presented no flow independent of time. The functional capillary density group B was higher than that of groups C and P, primarily after 24 hours. All groups showed an increase in D with time but reached similar final distances (C = 2.73, B = 2.78 and P = 2.70 cm). Moreover, the percentage of viable areas remained at approximately 50%. The orthogonal polarization spectral imaging was useful to assess viability by counting fields with and without blood flow.CONCLUSIONSFunctional capillary density values were higher in the buflomedil group compared to the control and pentoxifylline groups in this model. Functional capillary density did not influence D or the percentage of VA, and the technique showed favorable potential to assess/predict the viability of skin flaps within 1 h after surgery.

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