Objective To compare the effects of two kinds of cannulation sites on the myocardial oxygen metabolism during left ventricular assistance to provide experimental basis for clinical selection of proper cannulation sites. Methods Twelve mongrel dogs were randomized equally into the left atrium to aorta group （LA group） and left ventricle to aorta group （LV group）, and underwent left ventricular assistance. At different times before and during left ventricular assistance, the heart rate, coronary sinus flow rate and blood gas were determined and coronary sinus oxygen saturation, arteriovenous oxygen difference and myocardial oxygen consumption were calculated. Results There was no statistical difference of heart rate in both groups（P〉0. 05）. The coronary sinus flow rate and mean myocardial oxygen consumption reduced in both groups after left ventricular assistance, whereas the effect was more remarkable in the LV group （P〈0.01）. Conclusion Both cannulation methods could reduce the myocardial oxygen consumption during left ventricular assistance, and the effect is more apparent in left ventricular cannulation.
Objective To study the application of pressure regulated volume control ventilation in respiratory support after liver transplantation. MethodsTwenty patients underwent liver transplantation were randomly averagely divided into two groups: pressure regulated vlume control ventilation (PRVCV) group and volume control (VC) group. The parameters of respiratory mechanics, hemodynamics and blood gas analysis of patients in two groups were compared, such as oxygen delivery (DO2), oxygen consumption (VO2), oxygen incepation ratio (O2ER), arteriovenous oxygen content difference (C(a-v)O2), cardiac output (CO), mean arterial pressure (mABP), mean pulmonary arterial pressure (mPAP), alveolar-arterial PO2 difference 〔P(A-a)O2〕, gas exchange index (PaO2/FiO2)， ratio of shunted blood to total perfusion (Qs/Qt), peak inspiratory pressure (PIP) and mean airway pressure (mAP). Results The P(A-a)O2 and Qs/Qt were significantly decreased in PRVCV group than those in VC group 〔P(A-a)O2: (101.42±28.07) mm Hg vs. (136.76±39.13) mm Hg; Qs/Qt: (1.78±0.86)% vs. (3.28±0.99)%〕, P＜0.05, P＜0.05， while the C(a-v)O2 and O2ER were significantly increased 〔C(a-v)O2: (20.70±10.41) mm Hg vs. (12.83±2.49) mm Hg; O2ER: (16.34±9.79)% vs. (9.37±1.83)%〕, P＜0.05, P＜0.01. There was no difference in the hemodynamics and airway pressure parameters between PRVCV group and VC group. Conclusion PRVCV mode could be a more suitable mechanical ventilation pattern to patients after liver transplantation.
Objective To study the effects of different levels of intra-abdominal pressure （IAP） on hemodynamics and oxygen metabolism in pig and to find the parameters early reflecting hemodynamics and oxygen metabolism of intra-abdominal hypertension （IAH）. Methods Fifteen pigs were anaesthetized, and trachea intubation and transfemoral cannula were performed then. Swan-Ganz catheters were inserted to pulmonary artery via internal jugular vein, and aeroperitoneum was set up by airing CO2. These pigs were randomly divided into three groups (5 pigs in each group) according to different levels of IAP （IAP10, IAP20, IAP30）. Hemodynamics and oxygen metabolism values were observed and recorded before airing, 6, 12, 18 and 24 hours after airing, respectively. Results There was no remarkable changes of hemodynamics and oxygen metabolism values in IAP10 group （Pgt;0.05）； When the IAP level reached 20 cm H2O, there was significant elevation （P＜0.01) in artery blood lacticacid （ABL）, and mixed venous oxygen saturation （SvO2） decreased significantly （P＜0.05) at 24 hours. When the IAP level reached 30 cm H2O, HR began to increase significantly at 18 hours after airing （P＜0.05). After 24 hours, all the indices of hemodynamics and oxygen metabolism were either significantly increased or decreased in IAP30 group. Two pigs in the group of IAP30 died during 24 hours after airing, while other pigs survived. Conclusion This study demonstrates that the hemodynamics and oxygen metabolism values begin to change in pigs when the IAP level reaches 20 cm H2O, and high level of IAP that lasted for 24 hours shows deterioration of hemodynamic and oxygenation levels. The indices of SvO2 and ABL can early reflect tissue oxygenation in IAH.
Objective To explore the relationship between central venous-to-arterial carbon dioxide difference/arterial-to-venous oxygen difference ration [P(cv-a)CO2/C(a-cv)O2] and arterial lactate in patients with sepsis. Methods A retrospective analysis was carried on 36 septic patients who were admitted to the Intensive Care Unit of Nanjng Drum-tower Hospital affiliated to Medical School of Nanjing University from May 2013 to November 2013. Cardiac index was measured by transpulmonary thermodilution. At the same time, femoral artery and central venous blood were collected to measure the value of arterial lactate and central venous oxygen saturation (ScvO2) by blood gas analysis and calculate central venous-to-arterial carbon dioxide difference [P(cv-a)CO2], arterial-to-venous oxygen difference [C(a-cv)O2], and their ration [P(cv-a)CO2/C(a-cv)O2], oxygen delivery (DO2) and oxygen consumption (VO2). The subjects were divided intoahyperlactatemia group (≥2 mmol/L) andanormal lactate group (< 2 mmol/L) according to arterial lactate value. P(cv-a)CO2/C(a-cv)O2 and other oxygen metabolism parameters were compared between two groups. Receiver operating characteristic (ROC) curve was used to evaluate the accuracy of P(cv-a)CO2/C(a-cv)O2 and other parameters for diagnosis of hyperlactatemia. Results A total of 36 patients with 119 data were collected. Compared with the normal lactate group, P(cv-a)CO2/C(a-cv)O2 was significantly higher [(1.38±0.76)mm Hg/mL vs. (2.31±1.01) mm Hg/mL, P < 0.01], ScvO2, DO2 and VO2 were significantly lower in the hyperlactatemia group [ScvO2: (74.26±9.13)% vs. (70.29±9.72)%; DO2: (505.52±208.39) mL/(min·m2) vs. (429.98±173.63) mL/(min·m2)]; VO2: (129.01±54.94) mL/(min·m2) vs. (109.99±38.79) mL/(min·m2), P < 0.05]. P(cv-a)CO2 had no significant difference between two groups [(5.76±3.70) mm Hg vs. (6.59±3.70) mm Hg, P > 0.05]. P(cv-a)CO2/C(a-cv)O2 was positively correlated with lactate (r=0.646, P < 0.01). ScvO2 was negatively correlated with lactate (r=-0.277, P < 0.01). DO2 and VO2 had no significant correlation with lactate (P > 0.05). The area under ROC curve (AUC) of P(cv-a)CO2 /C(a-cv)O2 for diagnosis of hyperlactatemia was 0.820, with 95% confidence interval (95%CI) of 0.715 - 0.925(P < 0.001); The AUC of ScvO2 was 0.622, with 95%CI of 0.520 - 0.724(P=0.025). Conclusion Compared with the traditional oxygen metabolism parameters, P(cv-a)CO2/C(a-cv)O2 can accurately diagnose hyperlactatemia, and isareliable parameter to reflect oxygen metabolism in patients with sepsis.
Objectives To investigate the effect of the combined treatment with probiotics and lactulose of gastrointestinal function and postoperative infection after open cardiac surgery. Methods We retrospectively analyzed the clinical data of 264 patients underwent cardiopulmonary bypass in our hospital between August 2013 and June 2014. There were 129 males and 135 females at the mean age of 53.06±10.97 years. We divided those patients into a treatment group and a control group. In the treatment group, there were 58 males and 63 females at the mean age of 52.29±14.31 years. They took probiotics and lactulose from the first day to the seventh day after operation. In the control group, there were 71 males and 72 females at the mean age of 52.29±14.31 years. They didn’t take probiotics or lactulose after the surgery. Procalcitonin (PCT) and lipopolysaccharides (LPS) concentrations were measured before operation, at 24 hours postoperatively, at 72 hours and on the seventh day. We recorded the condition of postoperative infection, gastrointestinal disorders and relative informations. Results The PCT and LPS concentrations in the treatment group after 72 hours postoperatively were statistically lower than those of the control group (1.04±5.39 ng/ml vs. 3.51±4.28 ng/ml, P=0.04; 11.28±4.34 EU/ml vs. 21.59±7.34 EU/ml, P=0.03). The PCT and LPS concentrations in the treatment group were also statistically lower than those of the control group on the 7th day postoperatively (0.17±2.79 ng/ml vs. 1.98±4.62 ng/ml，P=0.04; 6.74±6.38 EU/ml vs. 15.96±4.61 EU/ml, P=0.01). The ICU stay time (43.25±14.36 h vs. 63.47±24.46 h, P=0.01) and postoperative hospital stay time (15.07±4.52 d vs. 21.08±6.49 d, P=0.02) were significantly less in the treatment group than those in the control group. The morbidity of infection and the morbidity of gastrointestinal disorders of the treatment group were statistically less than those of the control group (1.65% vs. 5.59%, P=0.00; 2.48% vs. 6.99%, P<0.001), and there was no statistical difference in mortality between the two groups (1.65% vs. 2.10%, P=0.12). Conclusions The combined treatment with probiotics and lactulose can improve the postoperative inflammatory reaction, gastrointestinal function, and reduce the morbidity of infection.
Objective To monitor the distribution of blood perfusion during aortic arch aneurysm surgery under double arterial lines with single pump. Methods We retrospectively analyzed the clinical data of 37 patients underwent aortic arch repair or reconstruction between September 2012 and April 2014. There were 9 females and 28 males at mean age of 48.1±10.8 years ranging from 19.0-72.0 years.We took double arterial lines with single pump for cardiopulmonary bypass (CPB) during the operation and we monitored the perfusion tube flow of both the upper and lower body by blood flow detector. Cerebral blood perfusion was measured by transcranial cerebral Doppler and near-infrared spectroscopy cerebral oxygen saturation (rSO2). Results The mean CPB time of all 37 patients was 195.8±40.5 minutes ranging from 136.0-277.0 minutes and the mean duration time of selective antegrade cerebral perfusion (SCAP) was 21.6±5.6 minutes ranging from 5.0-35.0 minutes. During cooling and rewarming phases, the part of blood flow through axillary artery cannulation ranged from 31.5% to 40.8% of the whole body perfusion. The blood flow of SACP was increased to 15.0 ml / (kg·min) in 2 patients with significantly lower rSO2 and middle cerebral artery blood flow during SACP, and they had an uneventful recovery process after surgery. There were another 2 patients recorded abnormal situation of rSO2 without interventions. One patient died and the other one recovered with compications of spinal cord. Conclusions The technique of double arterial lines with single pump is reasonable and effective. The cerebral perfusion monitoring is helpful to detect abnormal perfusion during aortic arch aneurysm surgery.
Objective To investigate the value of central venous-to-arterial carbon dioxide difference/arterial-to-venous oxygen difference ratio [P(cv-a)CO2/C(a-cv)O2] in predicting oxygen metabolism after fluid resuscitation in patients with septic shock. Methods A prospective observational study was carried out on septic shock patients admitted in the intensive care unit of Nanjng Drum Tower Hospital from November 2013 to April 2014. All patients underwent fluid challenge (300 ml saline for 20 min, rapid intravenous infusion). The patients were divided into a fluid responded group (ΔCI≥10%) and a fluid unresponded group (ΔCI＜10%), according to the change of cardiac output index (ΔCI) after fluid challenge. Then the patients were divided into two subgroups in the fluid responded group, namely a ΔVO2≥10% group and a ΔVO2＜10% group, according to the change of VO2 (ΔVO2). Cardiac output index (CI) were determined by pulse indicator continuous cardiac output (PICCO). Hemoglobin, arterial carbon dioxide (PaCO2), arterial oxygen (PaO2), arterial oxygen saturation (SaO2), arterial blood lactate, central venous carbon dioxide (PcvCO2), central venous oxygen (PcvO2) and central venous oxygen saturation (ScvO2) were measured by blood gas analysis. P(cv-a)CO2/C(a-cv)O2 and oxygen consumption (VO2) were calculated. P(cv-a)CO2/C(a-cv)O2 before and after fluid challenge was compared between two subgroups. Results Fluid challenges were performed in 23 instances in 18 patients, among which 17 instances were defined as the fluid responded group. Compared with the fluid unresponded group, P(cv-a)CO2/C(a-cv)O2, arterial lactate and ScvO2 had no significant difference [P(cv-a)CO2/C(a-cv)O2](mm Hg/ml): 2.05±0.75vs. 1.58±0.67; arterial lactate (mmol/l): 3.78±2.50vs. 3.26±2.42; ScvO2(%): 73.71±9.64vs. 70.30±12.01,P＞0.05] in the fluid responded group before resuscitation. In the fluid responded group, there were 10 instances in the ΔVO2≥10% group and 7 instances in the ΔVO2＜10% group. P(cv-a)CO2/C(a-cv)O2 (mm Hg/ml) was significantly higher in the ΔVO2≥10% group before resuscitation compared with the ΔVO2＜10% group (2.43±0.73vs. 1.51±0.37,P＜0.01). Lactate (mmol/l) was also higher in the ΔVO2≥10% group before resuscitation (4.53±2.52vs. 1.46±0.82,P＜0.01). ScvO2 (%) had no significant difference between two groups (70.79±9.15vs. 72.13±13.42,P＞0.05). The areas under ROC curve (AUCs) of P(cv-a)CO2/C(a-cv)O2, lactate and ScvO2 for predicting ΔVO2≥10% were 0.843, 0.921, and 0.529, respectively. The sensitivity and specificity of P(cv-a)CO2/C(a-cv)O2≥1.885 mm Hg/ml for predicting ΔVO2≥10% after fluid resuscitation were 70% and 86%, respectively. Conclusion For septic shock patients with fluid responsiveness, P(cv-a)CO2/C(a-cv)O2 can predict oxygen metabolism after fluid resuscitation and can be used as a reliable parameter to guide fluid resuscitation.