Changes of small intestine villus and sublingual microcirculation in rabbits during endotoxic shock observed by sidestream dark-field imaging / 中国病理生理杂志

AIM: To investigate the changes of small intestine villus and sublingual microcirculation perfusion in the rabbits during endotoxic shock by sidestream dark-field imaging (SDF) after resuscitation to a mean arterial pressure (MAP) level.METHODS: New Zealand white rabbits (n=60) were randomly divided into 2 groups (group of villus and group of sublingua).The fistula operation of ileum was performed.Lipopolysaccharide was injected to establish endotoxic shock model, and fluid resuscitation (lactated Ringer's solution, 30 mL·kg-1·h-1) was given to maitain the MAP of the animals to 80 mmHg.Continuous norepinephrine was intravenously injected at 0.5~1 μg·kg-1·min-1 only if fluid therapy did not maintain the MAP level.The changes of microcirculatory perfusion indexes in small intestine villus and sublingual tissues such as vessels per villus (VV), microvascular flow index (MFI), proportion of perfused villi (PPVi), villus border score, villus vessel score, total vessel density (TVD), perfused vessel density (PVD) and proportion of perfused vessels (PPVe) were continuously observed and recorded by SDF before shock, during shock and after fluid resuscitation.RESULTS: MFI and PPVi in small intestine villus, and MFI, PPVe, TVD and PVD in sublingual tissues were significantly decreased after shock (P<0.01).Compared with MFI in sublingual microcirculation, MFI in villus was significantly decreased (P<0.01).MFI and PPVi in small intestine villus, and MFI, PPVe, TVD and PVD in sublingual tissues were improved after recovered to the target MAP by fluid resuscitation (P<0.05).However, MFI in small intestine villus was significantly lower than that in sublingual tissues after fluid resuscitation (P<0.01).CONCLUSION: The difference between small intestine villus and sublingual microcirculation perfusion during endotoxic shock is observed.The descent degree of microcirculation perfusion in small intestine villus is larger than that in sublingual tissues after shock, and the recovery degree of small intestine villus microcirculation is lower than that of sublingual microcirculation afer fluid resuscitation.

Changes of small intestinal villi microcirculation in sidestream dark-field imaging with different target blood pressure in rabbits during endotoxin shock / 中华危重病急救医学

Objective Changes of small intestine villus microcirculation perfusion in sidestream dark-field (SDF) imaging in the rabbits during endotoxic shock after fluid resuscitation with different target mean arterial pressure (MAP), and evaluation of feasibility of monitoring small intestine villus microcirculation by SDF were studied. Methods Sixty standard New Zealand white rabbits were randomly divided into two groups: low target MAP group (group A, n = 30) and high target MAP group (group B,n = 30). Fistula operation of ileum was madein vitro, and lipopolysaccharide (LPS, 2 mg/kg) was injected to establish endotoxic shock model. Group A was administered with the lower dose fluid resuscitation (lactated Ringer solution, 20 mL·kg-1·h-1) for target MAP of 65 mmHg (1 mmHg =0.133 kPa); group B was administered with the higher dose fluid resuscitation (lactated Ringer solution, 30 mL·kg-1·h-1) for MAP of 80 mmHg. Continuous norepinephrine intravenous injection (0.5-1.0μg·kg-1·min-1) was administered only after fluid therapy couldn't reach the target MAP. The changes of small intestine villus microcirculation perfusion indexes such as vessels per villus (VV), proportion of perfused villi (PPV), microvascular flow index (MFI), borders of villus score (BVS), vessels villus score (VVS) were continuously observed and recorded before the shock, during the shock and after fluid resuscitation using SDF imaging. The differences of microcirculation perfusion were compared between two groups using the specific parameter evaluation system to determine severity of villi microcirculation and injury scores at different stages.Results VV and borders of villus were clear and contact before shock in two groups. After shock, VV, PPV were significantly decreased in both two groups, the borders of villus were destroyed, MFI, BVS, VVS and the total score of villi injury microcirculation were obviously and severely decreased. Partial blood flow of villous capillaries after fluid resuscitation was recovered in two groups, but the perfusion of some region was un-balanced with the outworn borders of villus. VV were rose as compared before and after fluid resuscitation in groups A and B (vessels: 1.21±0.22 vs. 0.81±0.12, 1.54±0.28 vs. 0.79±0.13), and PPV [(31±4)% vs. (12±2)%, (38±5)% vs. (13±3)%], MFI (1.55±0.09 vs. 1.09±0.03, 1.97±0.11 vs. 1.05±0.03), VVS (points: 1.22±0.08 vs. 0.89±0.02, 2.06±0.15 vs. 0.90±0.02) and the sum of MFI, BVS, VVS (3.70±0.19 vs. 2.85±0.07, 5.01±0.29 vs. 2.88±0.08) were significant rose (allP 0.05).Conclusions For the small intestine villus microcirculation perfusion, the higher target MAP (80 mmHg) after fluid resuscitation or/and vasoconstrictor drugs usage were probably better than the relatively lower target MAP (65 mmHg) during endotoxic shock. SDF imaging is a very promising technique for intestinal villi microcirculatory visualization and assessment.

Evaluation of sublingual microcirculation in children with dengue shock

OBJECTIVE: To report the sublingual microcirculation observed using Sidestream Dark Field imaging in two children with dengue shock. METHOD: Two children, aged 9 and 10 years, were admitted to the pediatric intensive care unit with dengue shock and multiple organ dysfunction. Sublingual microcirculation was assessed in each patient on the first and second days of shock and was assessed a final time when the patients were no longer in shock (on the day prior to extubation) using Sidestream Dark Field technology. The De Backer score and microvascular flow index were used for the analyses. RESULTS: Both patients had reduced perfused small vessel density in the first two days and showed predominantly intermittent or no microcirculation flow, as demonstrated by a low microvascular flow index. The blood flow in the large vessels was not affected. Prior to the extubation, the microvascular flow index had increased, although the perfused small vessel density remained diminished, suggesting persistent endothelial dysfunction. CONCLUSIONS: Severe microcirculation changes may be involved in the pathophysiological mechanisms that lead to the final stages of dengue shock, which is frequently irreversible and associated with high mortality rates. Microcirculatory monitoring may help elucidate the physiopathology of dengue shock and prove useful as a prognostic tool or therapeutic target. .

Effect of EGDT on tissue perfusion in patients with septic shock / 中华急诊医学杂志

Objective To observe the effect of early goal directed therapy (EGDT) on tissue perfusion,microcirculation and tissue oxygenation in patients with septic shock.Methods A prospective observational study was carried out in 20 patients with early septic shock admitted to ICU within 24 hours after onset.Patients with one of following conditions,including stroke,brain injury,other types of shock,severe heart failure,acute myocardium infarction,ages below 18,pregnancy,terminal stage of disease,cardiac arrest,extensive bums,mouth bleeding,oromandiblular dyetonia (difficult to open the mouth),and the time elapsed over 24 hours after onset of septic shock,were excluded.The eligible patients were treated with the standard procedure of EGDT.The partial pressure of transcutaneous oxygen and carbon dioxide (PtcO2,PtcCO2) was monitored and hemodynamic data were recorded.Sidestream dark field imaging device was applied to detect the sublingual microcirculation.Hemodynamics,tissue oxygen,and sublingual microcirculation were compared before treatment and after EGDT.When the variables met the normal distribution,t test was applied.Otherwise,Wilcoxon test was used.Correlation between variables was analyzed with Pearson Correlation Analysis.Results Of 20 patients,19 met all 4 elements in criteria of EGDT after treatment and were eligible for study.PtcO2 and PtcCO2 were monitored in 19 patients.Sublingual microcirculation was obtained in four of them.(1) After the criteria of EGDT were entirely met,PtcO2 increased from (62.7 ± 24.0) mm Hg to (78.0 ± 30.9) mm Hg (P ＜ 0.05) ; tissue oxygenation index (PtcO2/FiO2) was (110.7 ± 60.4) mm Hg before treatment and (141.6 ± 78.2) mm Hg after EGDT (P ＜ 0.05).PtcCO2 and PaCO2 gap (difference between PtcCO2 and PaCO2) decreased significantly after EGDT (P ＜ 0.05).(2) Both proportion of small vessels with perfusion (PVP) and microcirculatory flow index of small vessels (MFI) showed a trend of increase after EGDT,but there were no significant differences between pre-and post-EGDT (P was 0.051 and 0.074 respectively).(3) PtcO2,PtcO2/FiO2,and PtcCO2 were not linearly related to central venous saturation,lactate,oxygen delivery,and oxygen consumption (All P ＞ 0.05).Conclusions Peripheral perfusion improved after EGDT in patients with septic shock but those hemodynamic variables might not exactly reflect the authenticity of global perfusion.

Effect of early goal directed therapy on tissue perfusion in patients with septic shock / 世界急诊医学杂志（英文）

@#BACKGROUND: This study aimed to observe the effect of early goal directed therapy (EGDT) on tissue perfusion, microcirculation and tissue oxygenation in patients with septic shock. METHODS: Patients with early septic shock (<24 hours) who had been admitted to the ICU of Zhongda Hospital Affiliated to Southeast University from September 2009 through May 2011 were enrolled (research time: 12 months), and they didn't meet the criteria of EGDT. Patients who had one of the following were excluded: stroke, brain injury, other types of shock, severe heart failure, acute myocardial infarction, age below 18 years, pregnancy, end-stage disease, cardiac arrest, extensive burns, oral bleeding, difficulty in opening the mouth, and the onset of septic shock beyond 24 hours. Patients treated with the standard protocol of EGDT were included. Transcutaneous pressure of oxygen and carbon dioxide (PtcO2, PtcCO2) were monitored and hemodynamic measurements were obtained. Side-stream dark field (SDF) imaging device was applied to obtain sublingual microcirculation. Hemodynamics, tissue oxygen, and sublingual microcirculation were compared before and after EGDT. If the variable meets the normal distribution, Student's t test was applied. Otherwise, Wilcoxon's rank-sum test was used. Correlation between variables was analyzed with Pearson's product-moment correlation coefficient method. RESULTS: Twenty patients were involved, but one patient wasn't analyzed because he didn't meet the EGDT criteria. PtcO2 and PtcCO2 were monitored in 19 patients, of whom sublingual microcirculation was obtained. After EGDT, PtcO2 increased from 62.7±24.0 mmHg to 78.0±30.9 mmHg (P<0.05) and tissue oxygenation index (PtcO2/FiO2) was 110.7±60.4 mmHg before EGDT and 141.6±78.2 mmHg after EGDT (P<0.05). The difference between PtcCO2 and PCO2 decreased significantly after EGDT (P<0.05). The density of perfused small vessels (PPV) and microcirculatory flow index of small vessels (MFI) tended to increase, but there were no significant differences between them (P>0.05). PtcO2, PtcO2/FiO2, and PtcCO2 were not linearly related to central venous saturation, lactate, oxygen delivery, and oxygen consumption (P>0.05). CONCLUSION: Peripheral perfusion was improved after EGDT in patients with septic shock, and it was not exactly reflected by the index of systemic perfusion.