Microcirculatory dysfunction is an important pathophysiological change of shock. In the last decade, many researches on the mechanism of microcirculatory dysfunction have been involved in areas such as the glycocalyx damage of vascular endothelial cells, macrocirculation- microcirculation discoupling, vascular hyporeactivity, and microcirculation monitoring. Accordingly, this paper discussed how these research findings can be applied to burn patients, with the aim of alerting the clinicians to improving microcirculation, and maintaining hemodynamic coordination during the treatment of burn shock and burn septic shock. In addition, with the development of accurate and reliable microcirculation monitoring techniques, it is necessary to carry out multi-center clinical trials to reveal the clinical significance of target-oriented shock resuscitation protocol combining macrocirculatory and microcirculatory parameters.
Burns/therapy* ; Endothelial Cells ; Hemodynamics/physiology* ; Humans ; Microcirculation/physiology* ; Resuscitation ; Shock ; Shock, Septic/therapy*

BackgroundMeasurement of general microcirculation remains difficult in septic shock patients. The peripheral perfusion index (PI) and sublingual microcirculation monitoring are thought to be possible methods. This study was performed to determine whether assessing microcirculation by PI and a new parameter, proportion of perfusion vessel change rate (△PPV) from sublingual microcirculation monitoring, can be associated with patients' outcome.

MethodsA prospective observational study was carried out, including 74 patients with septic shock in a mixed intensive care unit. Systemic hemodynamic variables were obtained at T0 and 6 h after (T6). PI and sublingual microcirculation indicators were obtained using a bedside monitor and a sidestream dark-field device, respectively. The t-test, analysis of variance, Mann-Whitney U-test, Kruskal-Wallis test, receiver operating characteristic curve analysis with the Hanley-McNeil test, survival curves using the Kaplan-Meier method, and the log-rank (Mantel-Cox) test were used to statistical analysis.

ResultsSystemic hemodynamics and microcirculation data were obtained and analyzed. Patients were divided into two groups based on whether the first 6 h lactate clearance (LC) was ≥20%; PI and △PPV were lower at T6 in the LC <20% group compared with LC ≥20% (PI: 1.52 [0.89, 1.98] vs. 0.79 [0.44, 1,81], Z = -2.514, P = 0.012; △PPV: 5.9 ± 15.2 vs. 17.9 ± 20.0, t = -2.914, P = 0.005). The cutoff values of PI and △PPV were 1.41% and 12.1%, respectively. The cutoff value of the combined indicators was 1.379 according to logistic regression. Area under the curve demonstrated 0.709 (P < 0.05), and the sensitivity and specificity of using combined indicators were 0.622 and 0.757, respectively. Based on the PI and △PPV cutoff, all the participants were divided into the following groups: (1) high PI and high △PPV group, (2) high PI and low △PPV group, (3) low PI and high △PPV group, and (4) low PI and low △PPV group. The highest Sequential Organ Failure Assessment score (14.5 ± 2.9) was in the low PI and low △PPV group (F = 13.7, P < 0.001). Post hoc tests showed significant differences in 28-day survival rates among these four groups (log rank [Mantel-Cox], 20.931; P < 0.05).

ConclusionPI and △PPV in septic shock patients are related to 6 h LC, and combining these two parameters to assess microcirculation can predict organ dysfunction and 28-day mortality in patients with septic shock.

Aged ; Female ; Hemodynamics ; physiology ; Humans ; Intensive Care Units ; Male ; Microcirculation ; physiology ; Middle Aged ; Prognosis ; Prospective Studies ; ROC Curve ; Sepsis ; physiopathology ; Shock, Septic ; physiopathology

PURPOSE: Endothelial dysfunction (ED) is a pivotal phenomenon in the development of cardiovascular disease (CVD) in patients receiving hemodialysis (HD). Indoxyl sulfate (IS) is a known uremic toxin that induces ED in patients with chronic kidney disease. The aim of this study was to investigate whether AST-120, an absorbent of IS, improves microvascular or macrovascular ED in HD patients. MATERIALS AND METHODS: We conducted a prospective, case-controlled trial. Fourteen patients each were enrolled in respective AST-120 and control groups. The subjects in the AST-120 group were treated with AST-120 (6 g/day) for 6 months. Microvascular function was assessed by laser Doppler flowmetry using iontophoresis of acetylcholine (Ach) and sodium nitroprusside (SNP) at baseline and again at 3 and 6 months. Carotid arterial intima-media thickness (cIMT) and flow-mediated vasodilation were measured at baseline and 6 months. The Wilcoxon rank test was used to compare values before and after AST-120 treatment. RESULTS: Ach-induced iontophoresis (endothelium-dependent response) was dramatically ameliorated at 3 months and 6 months in the AST-120 group. SNP-induced response showed delayed improvement only at 6 months in the AST-120 group. The IS level was decreased at 3 months in the AST-120 group, but remained stable thereafter. cIMT was significantly reduced after AST-120 treatment. No significant complications in patients taking AST-120 were reported. CONCLUSION: AST-120 ameliorated microvascular ED and cIMT in HD patients. A randomized study including a larger population will be required to establish a definitive role of AST-120 as a preventive medication for CVD in HD patients.
Acetylcholine ; Adult ; Carbon/*therapeutic use ; Cardiovascular Diseases/etiology/*prevention & control ; Carotid Intima-Media Thickness ; Endothelium, Vascular/*physiopathology ; Female ; Humans ; Iontophoresis ; Kidney Failure, Chronic/complications/*physiopathology/*therapy ; Laser-Doppler Flowmetry ; Male ; Microcirculation/physiology ; Middle Aged ; Nitroprusside ; Oxides/*therapeutic use ; Prospective Studies ; *Renal Dialysis ; Young Adult

BACKGROUNDThe decrease of glomerular filtration rate has been theoretically supposed to be the result of low perfusion in renal artery stenosis (RAS). But the gap between artery stenosis and the glomerular filtration ability is still unclear.

METHODSPatients with selective renal artery angiogram were divided by the degree of renal artery narrowing, level of estimated glomerular filtration rate (eGFR), respectively. The different levels of eGFR, renal microcirculation markers, and RAS severity were compared with each other, to determine the relationships among them.

RESULTSA total of 215 consecutive patients were enrolled in the prospective cohort study. Concentrations of microcirculation markers had no significant difference between RAS group (RAS ≥ 50%) and no RAS group (RAS < 50%) or did not change correspondingly to RAS severity. The value of eGFR in RAS group was lower than that in the no RAS group, but it did not decline parallel to the progressive severity of RAS. The microcirculation markers presented integral difference if grouped by different eGFR level with negative tendency, especially that plasma cystatin C (cysC) and urinary microalbumin to creatinine ratio (mACR) increased with the deterioration of eGFR, with strong (r = -0.713, P < 0.001) and moderate (r = -0.580, P < 0.001) correlations. In the subgroup analysis of severe RAS (RAS ≥ 80%), the levels of plasma cysC and urinary mACR demonstrated stronger negative associations with eGFR, (r = -0.827, P < 0.001) and (r = -0.672, P < 0.001) correlations, respectively.

CONCLUSIONSSeverity of RAS could not accurately predict the value of eGFR, whereas microcirculation impairment may substantially contribute to the glomerular filtration loss in patients with RAS.

Aged ; Female ; Glomerular Filtration Rate ; physiology ; Humans ; Male ; Microcirculation ; physiology ; Middle Aged ; Prospective Studies ; Renal Artery Obstruction ; physiopathology ; Retrospective Studies

Microcirculatory dysfunction of local wounds and distant tissues after burns results in ischemia and hypoxia of tissues and organs, thus affecting the course and prognosis of burns. Platelet is an important component of blood, and the changes in its rheological behavior influence the blood flow in the microcirculation, as well as the microvascular structure and function. The abnormality of platelet rheological behavior plays an important role in the occurrence and development of microcirculatory dysfunction after burn. Changes in rheological behavior of platelets are due to changes in platelet morphology, adhesion, aggregation, shrinkage functions, and release reaction. Investigation of platelet rheological behavior and its regulation after burn may be of significant implication in the analysis of patient's condition and instruction for treatment. This article reviews the changes in platelet rheological behavior and its regulation after burn in the aspects of morphology, adhesion, aggregation, shrinkage functions, and release reaction.
Blood Platelets ; physiology ; Burns ; blood ; physiopathology ; Hemodynamics ; Humans ; Microcirculation ; Platelet Aggregation ; Rheology

Athletes ; Humans ; Microcirculation ; Muscles ; physiology ; Sports

OBJECTIVEBased on the observation that coagulation necrosis occurs in the majority of neonatal necrotizing enterocolitis (NEC) patients, it is clear that intestinal ischemia is a contributing factor to the pathogenesis of NEC. However, the published studies regarding the role of intestinal ischemia in NEC are controversial. The aim of this paper is to review the current studies regarding intestinal microcirculatory dysfunction and NEC, and try to elucidate the exact role of intestinal microcirculatory dysfunction in NEC.

DATA SOURCESThe studies cited in this review were mainly obtained from articles listed in Medline and PubMed. The search terms used were "intestinal microcirculatory dysfunction" and "neonatal necrotizing enterocolitis".

STUDY SELECTIONMainly original milestone articles and critical reviews written by major pioneer investigators in the field were selected.

RESULTSImmature regulatory control of mesentery circulation makes the neonatal intestinal microvasculature vulnerable. When neonates are subjected to stress, endothelial cell dysfunction occurs and results in vasoconstriction of arterioles, inflammatory cell infiltration and activation in venules, and endothelial barrier disruption in capillaries. The compromised vasculature increases circulation resistance and therefore decreases intestinal perfusion, and may eventually progress to intestinal necrosis.

CONCLUSIONIntestinal ischemia plays an important role through the whole course of NEC. New therapeutic agents targeting intestinal ischemia, like HB-EGF, are promising therapeutic agents for the treatment of NEC.

Endothelin-1 ; physiology ; Endothelium, Vascular ; physiopathology ; Enterocolitis, Necrotizing ; drug therapy ; etiology ; pathology ; Heparin-binding EGF-like Growth Factor ; Humans ; Infant, Newborn ; Intercellular Signaling Peptides and Proteins ; therapeutic use ; Intestines ; blood supply ; Ischemia ; complications ; Microcirculation ; physiology ; Nitric Oxide ; physiology ; Splanchnic Circulation

BACKGROUNDHyperbaric oxygen preconditioning (HBO) is a new method of ischemia preconditioning. In this study, we examined its effects on skin flap survival and the mechanisms involved.

METHODSThirty-six rats were divided into three groups: HBO preconditioning, control, and sham groups. An extended epigastric adipocutaneous flap based on the right superficial epigastric artery and vein was raised. A 3-hour period of flap ischemia was induced by clamping the pedicle vessels with a microvascular clamp. At the end of ischemia induction, the clamp was removed and the flap was resutured. Rats in the HBO preconditioning group were treated with HBO four times before surgery. Microcirculation in the skin flap was measured on postoperative days 1, 3 and 5. The size of the flap was measured on postoperative day 5, before the animals were sacrificed. Samples of the skin flap were prepared and stained with hematoxylin and eosin. The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in the flap samples were measured.

RESULTSSurviving flap size was significantly higher in the HBO preconditioning group compared with controls, with a reduced inflammatory response and increased perfusion. IL-1, TNF-α, and IL-6 levels in the HBO preconditioning group were lower than in controls.

CONCLUSIONSHBO preconditioning improved flap survival in this ischemia-reperfusion rat model. The mechanisms responsible for this effect may relate to attenuation of the inflammatory response and increased flap perfusion following HBO preconditioning.

Animals ; Graft Survival ; Hyperbaric Oxygenation ; methods ; Ischemia ; surgery ; Male ; Microcirculation ; physiology ; Rats ; Rats, Sprague-Dawley ; Skin ; Surgical Flaps

OBJECTIVETo investigate the correlation between different Chinese medicine (CM) syndromes and variations in microcirculation in septic shock patients.

METHODSseventy Septic shock patients were divided into four groups: heat damaging qi-yin group (HDQY, 23 cases); yin exhaustion and yang collapse group (YEYC, 26 cases); excessive heat in Fu organ group (EHFO, 10 cases); and heat damaging nutrient-blood group (HDNB, 11 cases). Sublingual microcirculation parameters were observed by sidestream dark-field (SDF) imaging and scored by Acute Physiology and Chronic Health Evaluation II (APACHE II) and the Sequential Organ Failure Assessment (SOFA), and parameters of microcirculation perfusion variations and prognoses were analyzed.

RESULTSCompared with those with qi-yin heat damage, perfused vessel density (PVD) in other groups decreased dramatically (P<0.05), and APACHE II scores increased significantly (P<0.05). In addition, the recovery time was prolonged substantially (P<0.05), and the mixed venous oxygen saturation (SVO2) decreased (P<0.05). Blood lactic acid increased significantly (P<0.05), and the mixed SVO decreased (P<0.05), in the YEYC group. Compared with the thermal injury camp blood group, sublingual microcirculation parameter variations showed no obvious difference in the YEYC and EHFO groups (P>0.05). There were significant positive correlations between CM syndromes and APACHE II scoring in different groups (r=0.512, P<0.05). There were negative correlations between PVD and APACHE II scoring (r=-0.378, P=0.043), the proportion of perfused vessels (PPV) and APACHE II scoring (r=-0.472, P=0.008), as well as between the microvascular flow index (MFI) and APACHE II scoring (r=-0.424, P=0.023) in different patients.

CONCLUSIONSublingual microcirculation may serve as a clinical diagnostic parameter of the patient condition, as well as being a prognostic indicator.

Aged ; Dopamine ; therapeutic use ; Dose-Response Relationship, Drug ; Female ; Hemodynamics ; Humans ; Male ; Medicine, Chinese Traditional ; Microcirculation ; physiology ; Middle Aged ; Mouth Floor ; blood supply ; physiopathology ; Perfusion ; Shock, Septic ; blood ; drug therapy ; mortality ; physiopathology ; Syndrome

Chronic wounds pose a clinical challenge. Such wounds may present all over the body although the majority appear on the lower extremities. In the main, wounds are caused by hypertension (venous or arterial), diabetes, although infection, trauma, and animal bites can result in non-healing wounds. It is vital to have a reliable diagnosis in order to plan treatment. Despite advances in diagnostics and the development of standard care packages, chronic wounds present a growing burden to all societies. One of the problems faced is the poor understanding of the pathophysiology of wounds; it is commonly accepted that microcirculation is impaired in lower extremity chronic wounds. This paper is focused on the significance and assessment of impaired microcirculation.
Diabetic Foot ; pathology ; Humans ; Microcirculation ; Wound Healing ; physiology