BACKGROUND Hepatic venous pressure gradient(HVPG)is the gold standard for diagnosis of portal hypertension(PH),invasiveness and potential risks in the process of measurement limited its widespread use.AIM To investiga...BACKGROUND Hepatic venous pressure gradient(HVPG)is the gold standard for diagnosis of portal hypertension(PH),invasiveness and potential risks in the process of measurement limited its widespread use.AIM To investigate the correlation of computed tomography(CT)perfusion parameters with HVPG in PH,and quantitatively assess the blood supply changes in liver and spleen parenchyma before and after transjugular intrahepatic portosystemic shunt(TIPS).METHODS Twenty-four PH related gastrointestinal bleeding patients were recruited in this study,and all patients were performed perfusion CT before and after TIPS surgery within 2 wk.Quantitative parameters of CT perfusion,including liver blood volume(LBV),liver blood flow(LBF),hepatic arterial fraction(HAF),spleen blood volume(SBV)and spleen blood flow(SBF),were measured and compared before and after TIPS,and the quantitative parameters between clinically significant PH(CSPH)and non-CSPH(NCSPH)group were also compared.Then the correlation of CT perfusion parameters with HVPG were analyzed,with statistical significance as P<0.05.RESULTS For all 24 PH patients after TIPS,CT perfusion parameters demonstrated decreased LBV, increased HAF, SBV and SBF, with no statistical difference in LBF. Compared withNCSPH, CSPH showed higher HAF, with no difference in other CT perfusion parameters. HAFbefore TIPS showed positive correlation with HVPG (r = 0.530, P = 0.008), while no correlation wasfound in other CT perfusion parameters with HVPG and Child-Pugh scores.CONCLUSIONHAF, an index of CT perfusion, was positive correlation with HVPG, and higher in CSPH thanNCSPH before TIPS. While increased HAF, SBF and SBV, and decreased LBV, were found afterTIPS, which accommodates a potential non-invasive imaging tool for evaluation of PH.展开更多
Cerebral arteriovenous malformations(AVMs) have abnormally enlarged arteries and veins prone to spontaneous hemorrhage.Immediately following surgical excision of a cerebral AVM,even normal brain tissue surrounding the...Cerebral arteriovenous malformations(AVMs) have abnormally enlarged arteries and veins prone to spontaneous hemorrhage.Immediately following surgical excision of a cerebral AVM,even normal brain tissue surrounding the lesion is subject to hemorrhage,a phenomenon termed normal perfusion pressure breakthrough(NPPB) syndrome.According to this theory,arteries supplying cerebral AVMs become dilated and lose their capacity to dilate or constrict to autoregulate pressure.Acutely after removal of a cerebral AVM,excessive blood pressure in these arterial feeders can cause normal brain tissue to bleed.However,this theory remains controversial.We present a patient with a cerebral AVM that demonstrated cerebrovascular reactivity and argues against an assumption underlying the theory of NPPB syndrome.展开更多
·AIM: To investigate the effects of transient high perfusion pressure on the retinal vessel diameter and retinal ganglion cells.·METHODS: The animals were divided into four groups according to different infu...·AIM: To investigate the effects of transient high perfusion pressure on the retinal vessel diameter and retinal ganglion cells.·METHODS: The animals were divided into four groups according to different infusion pressure and infusion time(60 mm Hg-3min, 60 mm Hg-5min, 100 mm Hg-3min, 100 mm Hg-5min). Each group consisted of six rabbits. The left eye was used as the experimental eye and the right as a control. Retinal vascular diameters were evaluated before, during infusion, immediately after infusion, 5min, 10 min and 30 min after infusion based on the fundus photographs. Blood pressure was monitored during infusion. The eyes were removed after 24 h.Damage to retinal ganglion cell(RGC) was analyzed by histology.·RESULTS: Retina became whiten and papilla optic was pale during perfusion. Measurements showed significant decrease in retinal artery and vein diameter during perfusion in all of the four groups at the proximal of the edge of the optic disc. The changes were significant in the 100 mm Hg-3min group and 100 mm Hg-5min group compared with 60 mm Hg-3min group(P 1=0.025, P 2=0.000).The diameters in all the groups recovered completely after 30 min of reperfusion. The number of RGC)showed no significant changes at the IOP in 100 mm Hg with5 min compared with contralateral untreated eye(P 】0.05).·CONCLUSION: Transient fluctuations during infusion lead to temporal changes of retinal vessels, which could affect the retinal blood circulation. The RGCs were not affected by this transient fluctuation. Further studies are necessary to evaluate the effect of pressure during realtime phacoemusification on retinal blood circulation.展开更多
BACKGROUND Hepatic venous pressure gradient(HVPG)is the gold standard for diagnosis of portal hypertension(PH).However,its use can be limited because it is an invasive procedure.Therefore,it is necessary to explore a ...BACKGROUND Hepatic venous pressure gradient(HVPG)is the gold standard for diagnosis of portal hypertension(PH).However,its use can be limited because it is an invasive procedure.Therefore,it is necessary to explore a non-invasive method to assess PH.AIM To investigate the correlation of computed tomography(CT)perfusion of the liver with HVPG and Child-Pugh score in hepatitis B virus(HBV)-related PH.METHODS Twenty-eight patients(4 female,24 male)with gastroesophageal variceal bleeding induced by HBV-related PH were recruited in our study.All patients received CT perfusion of the liver before transjugular intrahepatic portosystemic stent-shunt(TIPS)therapy.Quantitative parameters of CT perfusion of the liver,including liver blood flow(LBF),liver blood volume(LBV),hepatic artery fraction,splenic blood flow and splenic blood volume were measured.HVPG was recorded during TIPS therapy.Correlation of liver perfusion with Child-Pugh score and HVPG were analyzed,and the receiver operating characteristic curve was analyzed.Based on HVPG(>12 mmHg vs≤12 mmHg),patients were divided into moderate and severe groups,and all parameters were compared.RESULTS Based on HVPG,18 patients were classified into the moderate group and 10 patients were classified into the severe group.The Child-Pugh score,HVPG,LBF and LBV were significantly higher in the moderate group compared to the severe group(all P<0.05).LBF and LBV were negatively associated with HVPG(r=-0.473,P<0.05 and r=-0.503,P<0.01,respectively),whereas splenic blood flow was positively associated with hepatic artery fraction(r=0.434,P<0.05).LBV was negatively correlated with Child-Pugh score.Child-Pugh score was not related to HVPG.Using a cutoff value of 17.85 mL/min/100 g for LBV,the sensitivity and specificity of HVPG≥12 mmHg for diagnosis were 80%and 89%,respectively.CONCLUSION LBV and LBF were negatively correlated with HVPG and Child-Pugh scores.CT perfusion imaging is a potential non-invasive quantitative predictor for PH in HBV-related liver cirrhosis.展开更多
Objective: To report a patient’s clinical course illustrative of the NPPB mechanism for hyperperfusion-induced injury. Methods: A 65-year-old female presented with a severe headache and was found to have a 6-cm right...Objective: To report a patient’s clinical course illustrative of the NPPB mechanism for hyperperfusion-induced injury. Methods: A 65-year-old female presented with a severe headache and was found to have a 6-cm right parietal AVM on imaging. The patient underwent staged, pre-operative embolization and the AVM was surgically resected without intra-operative complication. After the patient emerged from anesthesia she exhibited left hemiplegia and hemispatial neglect. Her systolic blood pressure (SBP) at that time was between 110-120 mmHg. SBP was reduced to 90-100 mmHg and the patient’s symptoms resolved shortly thereafter. The patient’s strict blood pressure goal was relaxed the next morning. However, with her SBP 110-120 mmHg in the ensuing hours, the patient’s left-sided neglect and hemiparesis returned. Her SBP was reduced again to 90-100 mmHg, leading to resolution of her symptoms. Results: This patient’s clinical course supports the NPPB theory of hyperperfusion-induced injury. Despite CT imaging demonstrating no residual AVM following resection, the patient developed neurological deficits in the immediate postoperative period. Aggressive systemic hypotension improved clinical symptoms repeatedly, whereas a brief period of normotension triggered a return of neurological deficits. As a result, there was a direct correlation between fluctuations of neurological status and SBP. This case suggests that the intrinsic autoregulatory capacity was altered in our patient, and that aggressive hypotension was necessary to compensate for diminished autonomic reactivity. Conclusions: This case provides further evidence that NPPB plays a role in hyperperfusion-induced injury following AVM excision and that blood pressure control is vital in managing hyperemic complications following complete resection of cerebral AVMs.展开更多
A retrospective analysis was performed of patients who received a paracentesis immediately following an intravitreal injection of bevacizumab or triamcinolone acetonide.These patients were previously diagnosed as havi...A retrospective analysis was performed of patients who received a paracentesis immediately following an intravitreal injection of bevacizumab or triamcinolone acetonide.These patients were previously diagnosed as having glaucoma,ocular hypertension,or had responded previously with sustained elevated intraocular pressure.Of 1661 procedures were performed.Totally 219(13%) of the injections were on phakic patients.A median(SD) of 210 μL(40 μL) of aqueous was removed during each paracentesis.There were no reported incidences of any complications.We propose performing a paracentesis immediately following intravitreal injections for patients at risk for ocular hypertension,glaucoma,and retinal vein or artery occlusion.展开更多
Objective To evaluate the association between diabetic retinopathy(DR) and mean ocular perfusion pressure(MOPP) in patients with type 2 diabetes mellitus(T2 DM).Methods Patients from the Fushun Diabetic Retinopathy Co...Objective To evaluate the association between diabetic retinopathy(DR) and mean ocular perfusion pressure(MOPP) in patients with type 2 diabetes mellitus(T2 DM).Methods Patients from the Fushun Diabetic Retinopathy Cohort Study(FS-DIRECT), a communitybased prospective cohort study conducted in northeast China, were included in this study. The presence and severity of DR were determined by grading fundus photographs according to the Early Treatment Diabetic Retinopathy Study(ETDRS) retinopathy scale. Systolic and diastolic blood pressure(SBP and DBP) were recorded using an electronic sphygmomanometer. Intraocular pressure(IOP) was measured using an iCare rebound tonometer. MOPP was calculated using the formula MOPP = 2/3 [DBP + 1/3(SBP-DBP)]-IOP.Results In total, 1,857 patients who had gradable fundus photography and MOPP data were enrolled in this study. Male patients had a higher MOPP than female patients(52.25 ± 8.75 vs. 50.96 ± 8.74 mmHg, P = 0.002). Overall, both male and female patients with any type of DR, non-proliferative DR(NPDR), or non-sight-threatening DR(non-STDR) had significantly higher MOPP relative to patients without DR. Increased MOPP(per 1 mmHg) was in turn associated with the presence of any type of DR[odds ratio(OR) = 1.03, 95% confidence interval(CI) : 1.02–1.04], NPDR(OR = 1.03 95% CI: 1.02–1.04),and non-STDR(OR = 1.03, 95% CI: 1.01–1.04) after adjusting for confounders. Increased MOPP(per 1 mmHg) was also associated with an increased likelihood of macular edema(OR = 1.02, 95% CI:1.01–1.04).Conclusions The results suggest that increased MOPP was associated with DR and macular edema in northeastern Chinese patients with T2 DM.展开更多
Background: Sufficient coronary perfusion pressure (CPP) to provide myocardial reperfusion is required for defibrillation success after prolonged ventricular fibrillation (VF) cardiac arrest. Chest compression interru...Background: Sufficient coronary perfusion pressure (CPP) to provide myocardial reperfusion is required for defibrillation success after prolonged ventricular fibrillation (VF) cardiac arrest. Chest compression interruptions cause a precipitous drop in CPP. Objective: To quantify the ex- tent to which CPP recovers to pre-pause levels following chest compression interruptions. Me- thods: This was a secondary analysis of data from two similar IACUC approved protocols. A total of 105 Yorkshire swine were included and VF was electrically induced. After 10 minutes of untreated VF in the first study (n = 52) and 12 minutes of untreated VF in the second (n = 53), CPR began and epinephrine was administered approximately 2 minutes prior to a planned 10-second pause to record an artifact-free ECG waveform segment. Following this pause, CPR was resumed for 20- seconds prior to defibrillation. CPP data were extracted from three time points: 2 minutes after epinephrine delivery (CPP1);following the chest compression pause (CPP2);and immediately before defibrillation (CPP3). Our primary outcome was defined as the ratio of CPP recovery (CPP3- CPP2) to the drop in CPP (CPP1-CPP2). Results: Interrupting compressions resulted in a significant drop in CPP (29.8 mmHg [95%CI: 26.2, 33.4] to 6.8 mmHg [95%CI: 5.4, 8.2]). Resuming CPR for restored 83% (95%CI: 78%, 86%) of the CPP lost. Conclusion: This study demonstrates that 83% of the decline in CPP values during a planned 10-second interruption in CPR can be restored with a short period of precordial compressions prior to defibrillation.展开更多
Background: This study was done to compare coronary perfusion pressure (CPP) prior to the first rescue shock (RS) among a group of animals that received intraosseous (IO) epinephrine 0.1 mg/ kg (high-dose epinephrine ...Background: This study was done to compare coronary perfusion pressure (CPP) prior to the first rescue shock (RS) among a group of animals that received intraosseous (IO) epinephrine 0.1 mg/ kg (high-dose epinephrine [HDE]) with a group that received intravenous (IV) epinephrine 0.01 mg/kg (standard-dose epinephrine [SDE]) during cardiac arrest resuscitation using a swine model of prolonged out-of-hospital ventricular fibrillation (VF) cardiac arrest. Methods: This was a secondary analysis of prospectively collected data from two IACUC approved protocols. Seventy-nine Yorkshire swine (25 - 35 kg) were surgically instrumented under anesthesia and VF was electrically induced. After 10 minutes of untreated VF in the IO study (n = 26) and 12 minutes of untreated VF in the IV study (n = 53), resuscitation commenced with closed chest compressions (CCC). A single dose of epinephrine (HDE IO or SDE IV, respectively) was given and flushed with saline. The CCC and RS attempts were standardized for all animals. The CPP was defined as aortic diastolic pressure minus right atrial diastolic pressure measured 2.5 minutes after medication delivery. Descriptive statistics were used to analyze the data. Results: Baseline group characteristics were mathematically the same. Just prior to the first RS, HDE IO resulted in a mean CPP of 33.2 mmHg (95%CI: 26.6, 39.9), while SDE IV resulted in a mean CPP of 25.0 mmHg (95%CI: 20.5, 29.4). Conclusion: This observation study reaffirms the assertion that HDE IO may be required to generate CPP values similar to SDE IV during resuscitation of prolonged VF.展开更多
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(...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.展开更多
AIM: To investigate the effects of body mass index (BMI) on intraocular pressure (IOP) and ocular pulse amplitude(OPA). METHODS: Totally 140 healthy individuals without any systemic diseases were included in the study...AIM: To investigate the effects of body mass index (BMI) on intraocular pressure (IOP) and ocular pulse amplitude(OPA). METHODS: Totally 140 healthy individuals without any systemic diseases were included in the study. BMI (kg/m2) was calculated for every individual. IOP and OPA were measured with Pascal Dynamic contour tonometer (DCT). Blood pressure was also measured along with the DCT. The patients were divided into three groups according to BMI as: Group1, BMI<25; Group2, 25≤BMI<30; Group3, BMI≥30. Mean values of IOP, OPA, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were used in statistical analysis.RESULTS: In Group1, the means of IOP, OPA, were 16.8±2.3mmHg, 2.7±0.7mmHg respectively; and SBP, DBP were 120.0±6.1mmHg, and 77.4±5.6mmHg respectively. In group2, the mean IOP, OPA, SBP, and DBP were found to be 16.6±2.1mmHg, 2.4±0.7mmHg, 121.7±5.3mmHg, and 79.5±4.9mmHg respectively. In group3, the mean IOP, OPA, SBP, and DBP were found to be 17.3±1.7mmHg, 2.1±0.7mmHg, 122.4±5.7mmHg, and 79.7±5.2mmHg respectively. There were no statistically significant difference between groups in terms of IOP, SBP and DBP, while OPA values were significantly lower in group3 (P=0.001). CONCLUSION: Decreased OPA values in individuals with higher BMI may indicate that subjects with higher BMI have lower choroidal perfusion and lower ocular blood flow.展开更多
Elevated intra-abdominal pressure(IAP)is a known cause of increased morbidity and mortality among critically ill patients.Intra-abdominal hypertension(IAH)and abdominal compartment syndrome can lead to rapid deteriora...Elevated intra-abdominal pressure(IAP)is a known cause of increased morbidity and mortality among critically ill patients.Intra-abdominal hypertension(IAH)and abdominal compartment syndrome can lead to rapid deterioration of organ function and the development of multiple organ failure.Raised IAP affects every system and main organ in the human body.Even marginally sustained IAH results in malperfusion and may disrupt the process of recovery.Yet,despite being so common,this potentially lethal condition often goes unnoticed.In 2004,the World Society of the Abdominal Compartment Syndrome,an international multidisciplinary consensus group,was formed to provide unified definitions,improve understanding and promote research in this field.Simple,reliable and nearly costless standardized methods of non-invasive measurement and monitoring of bladder pressure allow early recognition of IAH and timely optimized management.The correct,structured approach to treatment can have a striking effect and fully restore homeostasis.In recent years,significant progress has been made in this area with the contribution of surgeons,internal medicine specialists and anesthesiologists.Our review focuses on recent advances in order to present the complex underlying pathophysiology and guidelines concerning diagnosis,monitoring and treatment of this life-threatening condition.展开更多
Background:Elevated intracranial pressure(ICP)occurs in several physiological and pathological conditions,yet long-term sequellae are not common,which implies that blood flow is preserved above ischemic thresholds.Met...Background:Elevated intracranial pressure(ICP)occurs in several physiological and pathological conditions,yet long-term sequellae are not common,which implies that blood flow is preserved above ischemic thresholds.Methods:This pilot study sought to confirm this hypothesis using a closed cranial window model in a rat in which ICP was elevated to 120 mmHg for 12 min,and superficial cortical perfusion was measured by laser Doppler flowmetry and laser speckle flowmetry.Results:Following a transient increase,cortical blood flow decreased to between 25%and 75%of baseline.These levels correspond to disrupted metabolism and decreased protein synthesis but did not exceed thresholds for electrical signaling or membrane integrity.This may partially explain how some episodes of elevated ICP remain benign.Conclusion:The closed cranial window model provides a platform for prospective study of physiologic responses to artificially elevated ICP during neurosurgery to promote hemostasis.展开更多
Ohjectire To examine the hypothesis of normal perjusion pressure breakthrough (NPPB). Methods A modified Spetzler carotid -jugular (CJ) fistula model was created to imitate NPPB. In 9 male adult Sprague- Dawley rats, ...Ohjectire To examine the hypothesis of normal perjusion pressure breakthrough (NPPB). Methods A modified Spetzler carotid -jugular (CJ) fistula model was created to imitate NPPB. In 9 male adult Sprague- Dawley rats, the ipsilateral vertebral artery and bilateral external carotid arteries were occluded. The period of hypoperfusion CJ fistula was extended to 14 weeks, as a modofcation of Spetzler model. The histological change were examtned under transmission electron microscope 14 weeks after creation of the listula. Results Ischemic histological changes such as increased pinocytosis, increased lucency of the basal lamina, and frank necrosis of the cerebral capillary were found in rats of CJ fistula group. Conclusion The findings in this study suggest that blood - braln barrier (BBB) was impaired by chronic hypoperfusion. The impaired BBB mny be one of the important causes of the NPPB phenomenon.展开更多
基金Supported by the National Natural Science Foundation of China General Program,No. 81871461
文摘BACKGROUND Hepatic venous pressure gradient(HVPG)is the gold standard for diagnosis of portal hypertension(PH),invasiveness and potential risks in the process of measurement limited its widespread use.AIM To investigate the correlation of computed tomography(CT)perfusion parameters with HVPG in PH,and quantitatively assess the blood supply changes in liver and spleen parenchyma before and after transjugular intrahepatic portosystemic shunt(TIPS).METHODS Twenty-four PH related gastrointestinal bleeding patients were recruited in this study,and all patients were performed perfusion CT before and after TIPS surgery within 2 wk.Quantitative parameters of CT perfusion,including liver blood volume(LBV),liver blood flow(LBF),hepatic arterial fraction(HAF),spleen blood volume(SBV)and spleen blood flow(SBF),were measured and compared before and after TIPS,and the quantitative parameters between clinically significant PH(CSPH)and non-CSPH(NCSPH)group were also compared.Then the correlation of CT perfusion parameters with HVPG were analyzed,with statistical significance as P<0.05.RESULTS For all 24 PH patients after TIPS,CT perfusion parameters demonstrated decreased LBV, increased HAF, SBV and SBF, with no statistical difference in LBF. Compared withNCSPH, CSPH showed higher HAF, with no difference in other CT perfusion parameters. HAFbefore TIPS showed positive correlation with HVPG (r = 0.530, P = 0.008), while no correlation wasfound in other CT perfusion parameters with HVPG and Child-Pugh scores.CONCLUSIONHAF, an index of CT perfusion, was positive correlation with HVPG, and higher in CSPH thanNCSPH before TIPS. While increased HAF, SBF and SBV, and decreased LBV, were found afterTIPS, which accommodates a potential non-invasive imaging tool for evaluation of PH.
文摘Cerebral arteriovenous malformations(AVMs) have abnormally enlarged arteries and veins prone to spontaneous hemorrhage.Immediately following surgical excision of a cerebral AVM,even normal brain tissue surrounding the lesion is subject to hemorrhage,a phenomenon termed normal perfusion pressure breakthrough(NPPB) syndrome.According to this theory,arteries supplying cerebral AVMs become dilated and lose their capacity to dilate or constrict to autoregulate pressure.Acutely after removal of a cerebral AVM,excessive blood pressure in these arterial feeders can cause normal brain tissue to bleed.However,this theory remains controversial.We present a patient with a cerebral AVM that demonstrated cerebrovascular reactivity and argues against an assumption underlying the theory of NPPB syndrome.
基金Supported by Natural Science Foundation of Zhejiang Province(No.LY12H12004)
文摘·AIM: To investigate the effects of transient high perfusion pressure on the retinal vessel diameter and retinal ganglion cells.·METHODS: The animals were divided into four groups according to different infusion pressure and infusion time(60 mm Hg-3min, 60 mm Hg-5min, 100 mm Hg-3min, 100 mm Hg-5min). Each group consisted of six rabbits. The left eye was used as the experimental eye and the right as a control. Retinal vascular diameters were evaluated before, during infusion, immediately after infusion, 5min, 10 min and 30 min after infusion based on the fundus photographs. Blood pressure was monitored during infusion. The eyes were removed after 24 h.Damage to retinal ganglion cell(RGC) was analyzed by histology.·RESULTS: Retina became whiten and papilla optic was pale during perfusion. Measurements showed significant decrease in retinal artery and vein diameter during perfusion in all of the four groups at the proximal of the edge of the optic disc. The changes were significant in the 100 mm Hg-3min group and 100 mm Hg-5min group compared with 60 mm Hg-3min group(P 1=0.025, P 2=0.000).The diameters in all the groups recovered completely after 30 min of reperfusion. The number of RGC)showed no significant changes at the IOP in 100 mm Hg with5 min compared with contralateral untreated eye(P 】0.05).·CONCLUSION: Transient fluctuations during infusion lead to temporal changes of retinal vessels, which could affect the retinal blood circulation. The RGCs were not affected by this transient fluctuation. Further studies are necessary to evaluate the effect of pressure during realtime phacoemusification on retinal blood circulation.
基金the National Natural Science Foundation of China General Program,No.81871461.
文摘BACKGROUND Hepatic venous pressure gradient(HVPG)is the gold standard for diagnosis of portal hypertension(PH).However,its use can be limited because it is an invasive procedure.Therefore,it is necessary to explore a non-invasive method to assess PH.AIM To investigate the correlation of computed tomography(CT)perfusion of the liver with HVPG and Child-Pugh score in hepatitis B virus(HBV)-related PH.METHODS Twenty-eight patients(4 female,24 male)with gastroesophageal variceal bleeding induced by HBV-related PH were recruited in our study.All patients received CT perfusion of the liver before transjugular intrahepatic portosystemic stent-shunt(TIPS)therapy.Quantitative parameters of CT perfusion of the liver,including liver blood flow(LBF),liver blood volume(LBV),hepatic artery fraction,splenic blood flow and splenic blood volume were measured.HVPG was recorded during TIPS therapy.Correlation of liver perfusion with Child-Pugh score and HVPG were analyzed,and the receiver operating characteristic curve was analyzed.Based on HVPG(>12 mmHg vs≤12 mmHg),patients were divided into moderate and severe groups,and all parameters were compared.RESULTS Based on HVPG,18 patients were classified into the moderate group and 10 patients were classified into the severe group.The Child-Pugh score,HVPG,LBF and LBV were significantly higher in the moderate group compared to the severe group(all P<0.05).LBF and LBV were negatively associated with HVPG(r=-0.473,P<0.05 and r=-0.503,P<0.01,respectively),whereas splenic blood flow was positively associated with hepatic artery fraction(r=0.434,P<0.05).LBV was negatively correlated with Child-Pugh score.Child-Pugh score was not related to HVPG.Using a cutoff value of 17.85 mL/min/100 g for LBV,the sensitivity and specificity of HVPG≥12 mmHg for diagnosis were 80%and 89%,respectively.CONCLUSION LBV and LBF were negatively correlated with HVPG and Child-Pugh scores.CT perfusion imaging is a potential non-invasive quantitative predictor for PH in HBV-related liver cirrhosis.
文摘Objective: To report a patient’s clinical course illustrative of the NPPB mechanism for hyperperfusion-induced injury. Methods: A 65-year-old female presented with a severe headache and was found to have a 6-cm right parietal AVM on imaging. The patient underwent staged, pre-operative embolization and the AVM was surgically resected without intra-operative complication. After the patient emerged from anesthesia she exhibited left hemiplegia and hemispatial neglect. Her systolic blood pressure (SBP) at that time was between 110-120 mmHg. SBP was reduced to 90-100 mmHg and the patient’s symptoms resolved shortly thereafter. The patient’s strict blood pressure goal was relaxed the next morning. However, with her SBP 110-120 mmHg in the ensuing hours, the patient’s left-sided neglect and hemiparesis returned. Her SBP was reduced again to 90-100 mmHg, leading to resolution of her symptoms. Results: This patient’s clinical course supports the NPPB theory of hyperperfusion-induced injury. Despite CT imaging demonstrating no residual AVM following resection, the patient developed neurological deficits in the immediate postoperative period. Aggressive systemic hypotension improved clinical symptoms repeatedly, whereas a brief period of normotension triggered a return of neurological deficits. As a result, there was a direct correlation between fluctuations of neurological status and SBP. This case suggests that the intrinsic autoregulatory capacity was altered in our patient, and that aggressive hypotension was necessary to compensate for diminished autonomic reactivity. Conclusions: This case provides further evidence that NPPB plays a role in hyperperfusion-induced injury following AVM excision and that blood pressure control is vital in managing hyperemic complications following complete resection of cerebral AVMs.
文摘A retrospective analysis was performed of patients who received a paracentesis immediately following an intravitreal injection of bevacizumab or triamcinolone acetonide.These patients were previously diagnosed as having glaucoma,ocular hypertension,or had responded previously with sustained elevated intraocular pressure.Of 1661 procedures were performed.Totally 219(13%) of the injections were on phakic patients.A median(SD) of 210 μL(40 μL) of aqueous was removed during each paracentesis.There were no reported incidences of any complications.We propose performing a paracentesis immediately following intravitreal injections for patients at risk for ocular hypertension,glaucoma,and retinal vein or artery occlusion.
基金The study was supported by the Liaoning Provincial Natural Science Foundation of China[20170540328]Zhejiang Provincial Natural Science Foundation of China[LQ18H120004]Wenzhou Basic Scientific Research Project[Y20190632].
文摘Objective To evaluate the association between diabetic retinopathy(DR) and mean ocular perfusion pressure(MOPP) in patients with type 2 diabetes mellitus(T2 DM).Methods Patients from the Fushun Diabetic Retinopathy Cohort Study(FS-DIRECT), a communitybased prospective cohort study conducted in northeast China, were included in this study. The presence and severity of DR were determined by grading fundus photographs according to the Early Treatment Diabetic Retinopathy Study(ETDRS) retinopathy scale. Systolic and diastolic blood pressure(SBP and DBP) were recorded using an electronic sphygmomanometer. Intraocular pressure(IOP) was measured using an iCare rebound tonometer. MOPP was calculated using the formula MOPP = 2/3 [DBP + 1/3(SBP-DBP)]-IOP.Results In total, 1,857 patients who had gradable fundus photography and MOPP data were enrolled in this study. Male patients had a higher MOPP than female patients(52.25 ± 8.75 vs. 50.96 ± 8.74 mmHg, P = 0.002). Overall, both male and female patients with any type of DR, non-proliferative DR(NPDR), or non-sight-threatening DR(non-STDR) had significantly higher MOPP relative to patients without DR. Increased MOPP(per 1 mmHg) was in turn associated with the presence of any type of DR[odds ratio(OR) = 1.03, 95% confidence interval(CI) : 1.02–1.04], NPDR(OR = 1.03 95% CI: 1.02–1.04),and non-STDR(OR = 1.03, 95% CI: 1.01–1.04) after adjusting for confounders. Increased MOPP(per 1 mmHg) was also associated with an increased likelihood of macular edema(OR = 1.02, 95% CI:1.01–1.04).Conclusions The results suggest that increased MOPP was associated with DR and macular edema in northeastern Chinese patients with T2 DM.
文摘Background: Sufficient coronary perfusion pressure (CPP) to provide myocardial reperfusion is required for defibrillation success after prolonged ventricular fibrillation (VF) cardiac arrest. Chest compression interruptions cause a precipitous drop in CPP. Objective: To quantify the ex- tent to which CPP recovers to pre-pause levels following chest compression interruptions. Me- thods: This was a secondary analysis of data from two similar IACUC approved protocols. A total of 105 Yorkshire swine were included and VF was electrically induced. After 10 minutes of untreated VF in the first study (n = 52) and 12 minutes of untreated VF in the second (n = 53), CPR began and epinephrine was administered approximately 2 minutes prior to a planned 10-second pause to record an artifact-free ECG waveform segment. Following this pause, CPR was resumed for 20- seconds prior to defibrillation. CPP data were extracted from three time points: 2 minutes after epinephrine delivery (CPP1);following the chest compression pause (CPP2);and immediately before defibrillation (CPP3). Our primary outcome was defined as the ratio of CPP recovery (CPP3- CPP2) to the drop in CPP (CPP1-CPP2). Results: Interrupting compressions resulted in a significant drop in CPP (29.8 mmHg [95%CI: 26.2, 33.4] to 6.8 mmHg [95%CI: 5.4, 8.2]). Resuming CPR for restored 83% (95%CI: 78%, 86%) of the CPP lost. Conclusion: This study demonstrates that 83% of the decline in CPP values during a planned 10-second interruption in CPR can be restored with a short period of precordial compressions prior to defibrillation.
文摘Background: This study was done to compare coronary perfusion pressure (CPP) prior to the first rescue shock (RS) among a group of animals that received intraosseous (IO) epinephrine 0.1 mg/ kg (high-dose epinephrine [HDE]) with a group that received intravenous (IV) epinephrine 0.01 mg/kg (standard-dose epinephrine [SDE]) during cardiac arrest resuscitation using a swine model of prolonged out-of-hospital ventricular fibrillation (VF) cardiac arrest. Methods: This was a secondary analysis of prospectively collected data from two IACUC approved protocols. Seventy-nine Yorkshire swine (25 - 35 kg) were surgically instrumented under anesthesia and VF was electrically induced. After 10 minutes of untreated VF in the IO study (n = 26) and 12 minutes of untreated VF in the IV study (n = 53), resuscitation commenced with closed chest compressions (CCC). A single dose of epinephrine (HDE IO or SDE IV, respectively) was given and flushed with saline. The CCC and RS attempts were standardized for all animals. The CPP was defined as aortic diastolic pressure minus right atrial diastolic pressure measured 2.5 minutes after medication delivery. Descriptive statistics were used to analyze the data. Results: Baseline group characteristics were mathematically the same. Just prior to the first RS, HDE IO resulted in a mean CPP of 33.2 mmHg (95%CI: 26.6, 39.9), while SDE IV resulted in a mean CPP of 25.0 mmHg (95%CI: 20.5, 29.4). Conclusion: This observation study reaffirms the assertion that HDE IO may be required to generate CPP values similar to SDE IV during resuscitation of prolonged VF.
文摘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.
文摘AIM: To investigate the effects of body mass index (BMI) on intraocular pressure (IOP) and ocular pulse amplitude(OPA). METHODS: Totally 140 healthy individuals without any systemic diseases were included in the study. BMI (kg/m2) was calculated for every individual. IOP and OPA were measured with Pascal Dynamic contour tonometer (DCT). Blood pressure was also measured along with the DCT. The patients were divided into three groups according to BMI as: Group1, BMI<25; Group2, 25≤BMI<30; Group3, BMI≥30. Mean values of IOP, OPA, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were used in statistical analysis.RESULTS: In Group1, the means of IOP, OPA, were 16.8±2.3mmHg, 2.7±0.7mmHg respectively; and SBP, DBP were 120.0±6.1mmHg, and 77.4±5.6mmHg respectively. In group2, the mean IOP, OPA, SBP, and DBP were found to be 16.6±2.1mmHg, 2.4±0.7mmHg, 121.7±5.3mmHg, and 79.5±4.9mmHg respectively. In group3, the mean IOP, OPA, SBP, and DBP were found to be 17.3±1.7mmHg, 2.1±0.7mmHg, 122.4±5.7mmHg, and 79.7±5.2mmHg respectively. There were no statistically significant difference between groups in terms of IOP, SBP and DBP, while OPA values were significantly lower in group3 (P=0.001). CONCLUSION: Decreased OPA values in individuals with higher BMI may indicate that subjects with higher BMI have lower choroidal perfusion and lower ocular blood flow.
文摘Elevated intra-abdominal pressure(IAP)is a known cause of increased morbidity and mortality among critically ill patients.Intra-abdominal hypertension(IAH)and abdominal compartment syndrome can lead to rapid deterioration of organ function and the development of multiple organ failure.Raised IAP affects every system and main organ in the human body.Even marginally sustained IAH results in malperfusion and may disrupt the process of recovery.Yet,despite being so common,this potentially lethal condition often goes unnoticed.In 2004,the World Society of the Abdominal Compartment Syndrome,an international multidisciplinary consensus group,was formed to provide unified definitions,improve understanding and promote research in this field.Simple,reliable and nearly costless standardized methods of non-invasive measurement and monitoring of bladder pressure allow early recognition of IAH and timely optimized management.The correct,structured approach to treatment can have a striking effect and fully restore homeostasis.In recent years,significant progress has been made in this area with the contribution of surgeons,internal medicine specialists and anesthesiologists.Our review focuses on recent advances in order to present the complex underlying pathophysiology and guidelines concerning diagnosis,monitoring and treatment of this life-threatening condition.
基金This work was supported by a grant from the National Institute of General Medical Sciences(F31GM089135)to MTO.
文摘Background:Elevated intracranial pressure(ICP)occurs in several physiological and pathological conditions,yet long-term sequellae are not common,which implies that blood flow is preserved above ischemic thresholds.Methods:This pilot study sought to confirm this hypothesis using a closed cranial window model in a rat in which ICP was elevated to 120 mmHg for 12 min,and superficial cortical perfusion was measured by laser Doppler flowmetry and laser speckle flowmetry.Results:Following a transient increase,cortical blood flow decreased to between 25%and 75%of baseline.These levels correspond to disrupted metabolism and decreased protein synthesis but did not exceed thresholds for electrical signaling or membrane integrity.This may partially explain how some episodes of elevated ICP remain benign.Conclusion:The closed cranial window model provides a platform for prospective study of physiologic responses to artificially elevated ICP during neurosurgery to promote hemostasis.
文摘Ohjectire To examine the hypothesis of normal perjusion pressure breakthrough (NPPB). Methods A modified Spetzler carotid -jugular (CJ) fistula model was created to imitate NPPB. In 9 male adult Sprague- Dawley rats, the ipsilateral vertebral artery and bilateral external carotid arteries were occluded. The period of hypoperfusion CJ fistula was extended to 14 weeks, as a modofcation of Spetzler model. The histological change were examtned under transmission electron microscope 14 weeks after creation of the listula. Results Ischemic histological changes such as increased pinocytosis, increased lucency of the basal lamina, and frank necrosis of the cerebral capillary were found in rats of CJ fistula group. Conclusion The findings in this study suggest that blood - braln barrier (BBB) was impaired by chronic hypoperfusion. The impaired BBB mny be one of the important causes of the NPPB phenomenon.