Objective To explore the significance of the plasma procalcitonin (PCT) level for directing antibiotic therapy in elderly patients with ventilator-associated pneumonia (VAP).Methods The 50 elderly patients with VAP were randomly separated into the regular therapy group and the PCT-directed therapy group. The regular therapy group was given regular antibiotic therapy, while the antibiotic therapy was decided according to the plasma level of PCT in the PCT-directed therapy group. The used time and utilization rate of antibiotics, as well as inflammatory indicators including white blood cells, neutrophils, C-reactive protein (CRP) and clinical pulmonary infection score (CPIS) were compared between the two groups. Results After treatment, there were no significant differences in white blood cells, neutrophils and CRP between the PCT-directed therapy group and regular therapy group [(8.9 ± 3.5 ) × 109/L vs. (9.4 ± 3.7) × 109/L, 0.62 ± 0.04 vs.0.60±0.04, (18.7±8.5) mg/Lvs. (21.6±6.0) mg/L, t=0.47, 1.84 and 1.37, allP＞0.05],but the CPIS was markedly lower in PCT-directed therapy group than in regular therapy group [(4.0± 1.4) scores vs. (4.7± 1.0) scores, t= 2. 18, P＜0.05]. The neutrophils, CRP and CPIS were significantly lower after treatment than before in the both groups. The concentration of PCT was decreased after treatment than before [(0.5 ± 0.9) mg/L vs. (1.7 ± 0.7) mg/L]. Meanwhile, the time using antibiotics was longer in regular treatment group than in PCT-directed therapy group [(8.72±1.32) d vs. (5.17±0.72) d, t=11.96, P＜0.01], the utilization rate of antibiotics was higher (95.2 % vs. 55.2 %, χ2 = 12.41, P＜0.01) in regular treatment group. Conclusions Using PCT levels for directing treatment in elderly patients with VAP can achieve better curative effect and reduce the use of antibiotics.

Objective To assess the effects of fluid resuscitation in elderly patients with septic shock by right ventricular end-diastolic volume index (RVEDVI). Method Thirty elderly patients with septic shock with-in 6 hours after onset, admired to intensive care unit of Zhejiang Hospital from January 2007 to October 2008, were randomly divided into control group (n = 15) and experimental group (n = 15). Homodynamic profile of the right ventricular was monitored by using modified Swan-Ganz catheter. Fluid resuscitation was given to the patients of control group monitored by right atria pressure (RAP). The expected efficacy of treatment was the RAP elevated to 8 ～ 12 mmHg. The goal of fluid resuscitation in patients of experimental group was 100～ 200 mL/m~2 RVEDVI corrected by right ventricular ejection fraction (RVEF). RAP, pulmonary artery occlusion pressure (PAOP), RVEF, RVEDVI, acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) and mixed venous oxygen sat-uration (SvO_2) were recorded before and after the treatment for 6 hours in both groups. The concentration of lactate and the lactate clearance rate of patients in both groups after fluid resuscitation were detected. The relationship between lactate clearance rate and ARVEDVI was evaluated by using correlation analysis. Results The percentage of patients reaching goal of resuscitation in experimental group (86.7%) was higher than that in control group (80%), however, there was no significant difference statistically. In goals-achieving group, RVEDVI, △RVEDVI, RVEF(%), RAP and lactate clearance rate(%) of the patients in experimental group were signifi-cantly higher than those in control group [(119.92 ± 15.65) mL/m~2, (38.54 ± 6.63) mL/m~2, (36.08 ± 3.40), (14.46±1.13) mmHg,(58.31 ± 13.36) vs. (99.92±11.71) mL/m~2,(21.00±11.01) mL/m~2,(32.42± 2.47),(13.08±1.08) mmHg,(43.99±16.26); P <0.05]. However, there was no significant difference in PAOP, APACHE Ⅱ and SvO_2 between two groups (P >0.05). The lactate clearance rate in goals-achieving pa-tients with septic shock has a significant correlation with RVEDVI and △RVEDVI (P < 0.01). Conclusions Fluid resuscitation guided by RVEDVI in elderly patients with septic shock is safe and more effective than that guided by RAP.

Objective To evaluate the predictive value of brain natriuretic peptide (BNP) on mortality in elderly patient with severe sepsis or septic shock. Method Eighty-three elderly patients meeting with criteria of severe sepsis or septic shock by the American College of Chest Physicians and the Society of Critical Care Medicine (ACCP/SCCM) in 2001, admitted in Intensive Care Unit (ICU) of Zhejiang Hospital during May 2004 to June 2007, were enrolled, and patients with chronic renal failure were excluded. The patients were divided into survivor and non - survivor group according to whether they survived within 28 days staying in ICU, the difference of plasma BNP level,serum C-creative protein (CRP) concentration, APACHE II and SOFA scores on admission day and BNP level on the third day between the two groups were compared; thereafter, the relationship between muhiple variables including age, admission day, BNP, CRP, APACHE 11 and SOFA scores, the 3rd day BNP level and 28-day mortality were analyzed by Logistic regression, and meanwhile the independent predictors for ICU moaality among which were determined. Results BNP levels on both admission day and the 3rd day were significantly higher in nomurvivor group than those in survivor group[ ( 1056.38±676.34) pg/ml vs. (611.59±610.02) pg/ml,p =0.002 and (1448.48+891.11) pg/ml vs. (522.41±575.20) pg/ml, P<0.001, respectively]. By Logistic regression analysis, BNP level on the 3rd day and SOFA score on admission day were independent predictors of ICU mortality, The receiver operating characteristic (ROC) curves indicated that values of areas under the curve of the admission day and the 3rd day BNP levels for 28-days mortality were 0.735 (95% CI,0. 621～0. 848, P <0.001) andO.836 (95% CI, 0.746～0,926,P<0.001), respectively. Conclusions Plasma BNP inereaseds in majority of eldedy patients with severe sepsis or septic shock, which may serve as irdex for prognosis in elderly severe septic paients.

Objective To investigate the association between body mass index (BMI) and exercise capacity in patients with chronic systolic heart failure.Methods The elderly patients with chronic systolic heart failure were consecutively recruited from 2008 to 2011 in cardiovascular clinic of Zhejiang Hospital.All the participants underwent height and weight measurements and BMI was calculated with these two parameters.Cardiopulmonary exercise test were performed to achieve peak oxygen uptake (PVO2),oxygen uptake to body mass ratio (PKVO2),oxygen uptake to heart ratio (VO2/HR) and ventilation/carbon dioxide production (VO2/VCO2).Results A total of the 273 patients with chronic systolic heart failure included 6 underweight patients (BMI ＜ 18.5 kg/m2),113 normal weight patients (BMI 18.5-＜ 24.0 kg/m2),116 overweight patients (BMI 24.0-＜ 28.0 kg/m2),and 38 obese patients (BMI ≥ 28 kg/m2).In both NYHA Ⅱ and Ⅲ/Ⅳ patients,unadjusted correlation analyses showed that BMI was positively related to PVO2 and VO2/HR,and was inversely related to PKVO2 and VE/VCO2 (P ＜ 0.05),respectively.Multiple stepwise regression analyses showed age,sex,BMI (P ＜ 0.05) and left ventricular ejection fraction (LVEF) were independent determinants of PKVO2,and age and BMI (P ＜ 0.05) were independent determinants of VE/VCO2.Conclusions BMI is significantly associated with exercise capacity in patients with chronic systolic heart failure,and also independent determinant for the PKVO2 and VE/VCO2,respectively.

Objective To investigate the influence of left ventricular-arterial coupling(VAC) on clinical prognosis of elderly patients with septic shock.Methods A total of 56 elderly septic shoek patients were enrolled in this study,all of whom were admitted to Department of Intensive Care Unit in Zhejiang Hospital from August 2014 to October 2015.The patients were divided into two groups according to the status of left ventricular-arterial coupling when septic shock was diagnosed,which were left ventricular-arterial uncoupling group(UC group) and left ventricular-arterial coupling group(C group).Various parameters were recorded,including blood lactate level,central venous oxygen saturation(ScvO2),serum level of N-terminal pro-brain natriuretic peptide(NT-proBNP) and cardiac troponin Ⅰ (cTN Ⅰ),dose of vasoactive drugs,the total fluid volume and urine volume per hour within 24 hours.The 28-day survival rate was a key index of prognosis.Multivariate logistic regression was taken to analyze risk factors related to death within 28 day.Results Compared with C group,UC group had lower values of left ventricular ejection fraction[(42.43 ±4.76)％ vs (53.17±3.01)％;P＜0.01] and cardiac index[(2.36±0.68) L· min-1 · m 2vs (2.93±0.45)L · min-1 · m-2;P ＜0.01].Yet serum levels of NT-proBNP[lg NT-proBNP 3.93 ±0.53 vs 3.40 ±0.63;P =0.004] and cTN Ⅰ [lg cTN Ⅰ-0.16 ± 0.68 vs-1.03 ± 0.69;P ＜ 0.001] in UC group were higher than those in C group.Moreover,the total fluid volume within 24 hours [(3 806.3 ± 831.4) ml vs (3 142.0±770.0) ml;P =0.016],blood lactate level[(5.61 ±2.68) mmol/L vs (3.93 ± 1.59)mmol/L;P =0.043] and dose of norepinephrine[(0.630 ±0.300) μg · kg-1 · min-1 vs (0.292 ±0.234)μg · kg-1 · min-1;P =0.001] in UC group were greater than those in C group,while ScvO2 [(60.75 ±2.91)％ vs (64.42 ±2.19)％;P＜0.001] and urine volume per hour[(0.518 ±0.358) ml vs (0.926 ±0.678) ml;P =0.007] were less than those in C group.Compared with C group,UC group had a lower 28-day survival rate [43.2％ (19/44) vs 9/12;P =0.049].Ea/Ees ratio was negatively correlated with LVEF,ScvO2 (r =-0.686,P ＜ 0.001;r =-0.411,P =0.002),positively correlated with NT-proBNP,cTN Ⅰ (r =0.294,P =0.028;r =0.363,P =0.006),yet no obvious correlation was noticed with blood lactate level (r =0.170,P =0.21).Multiple logistic regression analysis showed that VAC(OR =11.187,95％ CI 2.489-50.285;P =0.002),lactate level (OR =1.727,95 ％ CI 1.164-2.563;P =0.007) and lg cTN Ⅰ (OR =0.247,95 ％ CI 0.079-0.779;P =0.017) were independent risk factors affecting 28-day mortality.Conclutions In elderly patients with septic shock,left ventricular-arterial uncoupling indicates a lower 28-day survival rate,worse cardiac function and tissue perfusion.Ea/Ees ratio might sever as a predictive indicator of 28-day mortality.

0.05).Conclusions Fluid therapy guided by functional hemodynamic index SVV in elderly patients with severe sepsis under MV is safe and more effective than that guided by CVP.SVV is valuable in prodicting the response to fluid treatment in elderly patients with severe sepsis.

Objective To investigate the prognostic value of stroke volume variation (SVV) in patients with severe sepsis after early goal-directed therapy (EGDT). Method Thirty-eight mechanically ventilated patients with severe sepsis underwent EGTD were divided into high SVV (≥10%) group and low SW (< 10%) group according to the data obtained from pulse contour continuous cardiac output (PiCCO) analysis device. The differ-enees in the rate of 28-day survival, length of ICU stay, duration of meehanical ventilation and eomplieation of in-fection between two groups of patients were compared. The rate of 28-day survival of patients was analyzed by using Kaplain-Meier survival analysis, and the relationship between SVV and mortality within 28 days was analyzed by using logistic regression model. Results In comparison with low SVV group, the rate of 28-day survival of high SVV group was signifieantly increased (87.5 % vs. 57.1%, P = 0.032), the length of ICU stay was significantly shortened (27.1±9.2) vs. (41.6±10.0) (P = 0. 004) and duration of mechanical ventilation was significantly more brief (20.4±7.3) vs. (28.5±8.3) (P = 0.038). The rate of cumulative survival of patients in high SVV group was higher than that in low SVV group. In addition, logistie analysis showed SW < 10% increased the risk of 28-day mortality (OR = 3.97; 95% CI 1.63 - 9.21, P = 0. 014). Conclusions The SVV can be served as a prognostic indicator in patients with severe sepsis after EGDT.

Objective To investigate the role of damaged mitochondria in cardiac cell apoptosis in septic rats and the possible mechanism involved.Methods Seventy-two Sprague-Dawley rats were randomly (random number) divided into negative control group (n =18) and septic group (further divided into three groups as per rats sacrificed 6 h,12 h,and 24 h after endotoxin injection intra-peritoneally,n =18).The hearts of rats were taken.The changes of cardiac morphology were observed under light microscope and scanning electron microscope.Cell apoptosis in situ were examined by using terminal transferase-mediated dUTP nick end-labeling assay and nuclear factor-kappa B (NF-κB) activation in myocardium was detected by using Western blotting to estimate myocardial cell apoptosis.Mitochondrial lipid and protein oxidation were measured to assess oxidative stress,and mitochondrial superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were determined to estimate antioxidant defense.Results Septic induced inflammatory cells infiltration,myocardium degeneration and effusion in a time-dependent manner.A remarkable expansion of capillaries could be observed in the hearts of infected rats at post-challenge of 24 h.Compared with sham-treated rats,the percentage of apoptosis increased in a time-dependent manner in the hearts of infected rats at 6 h,12 h,24 h of post-injection (P ＜0.05).The concentration of NF-κB p65 in the cytosol decreased gradually and increased in the nucleus during sepsis in a time-dependent manner (P ＜0.05),indicating that septic challenge provoked progressive activation of NF-κB.Mitochondrial cristae disappeared in 6 h of challenge,and significant mitochondrial cristae disappearance,vacuolization,and rupture of mitochondria membrane became markedly obvious 12 and 24 h later.Both SOD and GPx activities decreased,while mitochondrial lipid and protein oxidation increased in a time-dependent manner after 6-24 h of challenge (P ＜ 0.05).Conclusions Septic challenge induced myocardial apoptosis and mitochondrial damage.Further,damaged mitochondria might play an important role by means of alteration of defenses against reactive oxygen species in myocardial cell apoptosis during sepsis.

Objective To investigate the clinical values of central venous pressure (CVP) versus stroke volume variation (SVV) in patients with severe sepsis after early goal-directed therapy (EGDT).Methods Totally 30 mechanically ventilated patients with severe sepsis who underwent goal-achieved EGDT were enrolled and randomly divided into CVP group (study group) and SVV group (control group) according to the data detected by pulse contour continuous cardiac output (PiCCO) analysis device.The differences in 28-day survival,3-day APACHE Ⅱ score,time of ICU stay,duration of mechanical ventilation,number that need CRRT,entral venous pressure (CVP),heart end-diastolic volume index (GEDVI),intrathoracic blood volume index (ITBVI),extravascular lung water index (EVLWI),cardiac index (CI),central venous oxygen saturation (ScvO2),lactate clearance rate and APACHE Ⅱ score were compared between the 2 groups.Results The death rate had no difference between the 2 groups(x2=0.240,P=0.624).Among survival patients in the CVP group,the time of ICU stay and duration of mechanical ventilation were shorter in study group than in control group(t=2.166,P=0.041;t=2.104,P=0.046),APACHE Ⅱ score at 3th day was decreased(t=2.20,P =0.038).The values of ITBVI,GEDVI,CI,lactate clearance rate were higher in study group than in control group (t=2.759,2.146,2.199,2.654,3.362,P=0.011,0.043,0.038,0.014,0.003).EVLWI and APACHE Ⅱ score were not different (P＞0.05) between the two groups.Conclusions SVV as a recovery target for fluid resuscitation can reach a better recovery results and improvement of prognosis than CVP goal-achieved EGDT.

In this paper, we propose the construction of a fifth-order Windkessel model, and give complete mathematical solutions for this model. Utilizing the diastolic pulse wave analytical methods, we derived the parameters of the mathematical model. The parameters were further applied to estimate arterial compliance, blood flow inertia, peripheral resistance and other indices. With simulation tools we assess the validity of the model, and built a simulation circuit with the model parameters R, C and L. The model parameters were obtained from the high-order Windkessel model. The stroke volume of left ventricle is employed as the input of the simulation circuit. At the end of the circuit, the responding signal was gained. And it in turn was compared with the measured pulse waveform. The results show that the fifth-order Windkessel model is superior to the third-order Windkessel model in the pulse wave fitting and stability, and thus better reflects the role of microvessles in the circulatory system.
Algorithms ; Blood Vessels ; physiology ; Compliance ; Computer Simulation ; Humans ; Microcirculation ; physiology ; Models, Cardiovascular ; Stroke Volume ; physiology