Effect of early goal directed therapy on tissue perfusion in patients with septic shock

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(PtcO_2,PtcCO_2) 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.PtcO_2 and PtcCO_2 were monitored in 19 patients,of whom sublingual microcirculation was obtained.After EGDT,PtcO_2 increased from 62.7+24.0 mmHg to 78.0±30.9mmHg(P<0.05) and tissue oxygenation index(PtcO_2/FiO_2) was 110.7+60.4 mmHg before EGDT and 141.6±78.2 mmHg after EGDT(P<0.05).The difference between PtcCO_2 and PCO_2 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).PtcO_2,PtcO_2/FiO_2,and PtcCO_2 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.

Quantifying tissue perfusion after peripheral endovascular procedures:Novel tissue perfusion endpoints to improve outcomes

Peripheral artery disease(PAD)is a flow-limiting condition caused by narrowing of the peripheral arteries typically due to atherosclerosis.It affects almost 200 million people globally with patients either being asymptomatic or presenting with claudication or critical or acute limb ischemia.PAD-affected patients display increased mortality rates,rendering their management critical.Endovascular interventions have proven crucial in PAD treatment and decreasing mortality and have significantly increased over the past years.However,for the functional assessment of the outcomes of revascularization procedures for the treatment of PAD,the same tests that have been used over the past decades are still being employed.Those only allow an indirect evaluation,while an objective quantification of limb perfusion is not feasible.Standard intraarterial angiography only demonstrates post-intervention vessel patency,hence is unable to accurately estimate actual limb perfusion and is incapable of quantifying treatment outcome.Therefore,there is a significant necessity for real-time objectively measurable procedural outcomes of limb perfusion that will allow vascular experts to intraop eratively quantify and assess outcomes,thus optimizing treatment,obviating misinterpretation,and providing significantly improved clinical results.The purpose of this review is to familiarize readers with the currently available perfusion-assessment methods and to evaluate possible prospects.

Retinal tissue hypoperfusion in patients with clinical Alzheimer’s disease

Background:It remains unknow whether retinal tissue perfusion occurs in patients with Alzheimer’s disease.The goal was to determine retinal tissue perfusion in patients with clinical Alzheimer’s disease(CAD).Methods:Twenty-four CAD patients and 19 cognitively normal(CN)age-matched controls were recruited.A retinal function imager(RFI,Optical Imaging Ltd.,Rehovot,Israel)was used to measure the retinal blood flow supplying the macular area of a diameter of 2.5 mm centered on the fovea.Blood flow volumes of arterioles(entering the macular region)and venules(exiting the macular region)of the supplied area were calculated.Macular blood flow was calculated as the average of arteriolar and venular flow volumes.Custom ultra-high-resolution optical coherence tomography(UHR–OCT)was used to calculate macular tissue volume.Automated segmentation software(Orion,Voxeleron LLC,Pleasanton,CA)was used to segment six intra-retinal layers in the 2.5 mm(diameter)area centered on the fovea.The inner retina(containing vessel network),including retinal nerve fiber layer(RNFL),ganglion cell-inner plexiform layer(GCIPL),inner nuclear layer(INL)and outer plexiform layer(OPL),was segmented and tissue volume was calculated.Perfusion was calculated as the flow divided by the tissue volume.Results:The tissue perfusion in CAD patients was 2.58±0.79 nl/s/mm^(3)(mean±standard deviation)and was significantly lower than in CN subjects(3.62±0.44 nl/s/mm^(3),P<0.01),reflecting a decrease of 29%.The flow volume was 2.82±0.92 nl/s in CAD patients,which was 31%lower than in CN subjects(4.09±0.46 nl/s,P<0.01).GCIPL tissue volume was 0.47±0.04 mm^(3) in CAD patients and 6%lower than CN subjects(0.50±0.05 mm^(3),P<0.05).No other significant alterations were found in the intra-retinal layers between CAD and CN participants.Conclusions:This study is the first to show decreased retinal tissue perfusion that may be indicative of diminished tissue metabolic activity in patients with clinical Alzheimer’s disease.

Novelties in the evaluation of microcirculation in septic shock

Microvascular alterations were first described in critically ill patients about 20 years ago. These alterations are characterized by a decrease in vascular density and presence of non-perfused capillaries close to well-perfused vessels. In addition, heterogeneity in microvascular perfusion is a key finding in sepsis. In this narrative review, we report our actual understanding of microvascular alterations, their role in the development of organ dysfunction, and the implications for outcome. Herein, we discuss the state of the potential therapeutic interventions and the potential impact of novel therapies. We also discuss how recent technologic development may affect the evaluation of microvascular perfusion.

Vacuum therapy in penile rehabilitation after radical prostatectomy： review of hemodynamic and antihypoxic evidence

Generally, hypoxia is a normal physiological condition in the flaccid penis, which is interrupted by regular nocturnal erections in men with normal erectile function.1 Lack of spontaneous and nocturnal erections after radical prostatectomy due to neuropraxia results in persistent hypoxia of cavernosal tissue, which leads to apoptosis and degeneration of cavernosal smooth muscle fibers. Therefore, overcoming hypoxia is believed to play a crucial role during neuropraxia. The use of a vacuum erectile device （VED） in penile rehabilitation is reportedly effective and may prevent loss of penile length. The corporal blood after VED use is increased and consists of both arterial and venous blood, as revealed by color Doppler sonography and blood gas analysis. A similar phenomenon was observed in negative pressure wound therapy （NPWT）. However, NPWT employs a lower negative pressure than VED, and a hypoperfused zone, which increases in response to negative pressure adjacent to the wound edge, was observed. Nonetheless, questions regarding ideal subatmospheric pressure levels, modes of action, and therapeutic duration of VED remain unanswered. Moreover, it remains unclear whether a hypoperfused zone or PO2 gradient appears in the penis during VED therapy. To optimize a clinical VED protocol in penile rehabilitation, further research on the mechanism of VED, especially real-time PO2 measurements in different parts of the penis, should be performed.

A case of scalp avulsion with prolonged ischemic time:indocyanine green angiography can aid in predicting replant survival

Background:Microsurgical replantation has become the most favorable treatment option for scalp avulsion.However,the accurate prediction of postoperative replant viability remains challenging.Case presentation:In this article,we showed that(indocyanine green angiography,ICGA)can provide a much more precise prediction of replant necrosis than conventional clinical assessment in a rare case of complete scalp avulsion with prolonged ischemia time.Conclusion:Clinical assessment of replant survival may be misleading in cases of complex tissue injuries and prolonged ischemic stress.This case provides insight into the promising utility of ICGA as an important adjuvant tool to better assess tissue perfusion and viability in scalp avulsion and possibly other types of replantation.