ObjectiveTo explore the influence of norepinephrine on the prediction of fluid responsiveness by passive leg raising (PLR) during septic shock. MethodsForty-six septic shock patients in intensive care unit of Nanjing Drum Tower Hospital were prospectively observed from September to November 2012. Among which 36 septic shock patients were enrolled with a positive PLR test (defined by an increase in stroke volume index ≥10%). A PLR test was performed at baseline (PLR1). A second PLR test (PLR2) was performed at returning to supine position for 10 min and the dose of norepinephrine was increased to maintain MAP ≥65 mmHg for 20 min. The changes of heart rate(HR),mean arterial pressure(MAP),central venous pressure(CVP),cardiac index(CI),stroke volume index(SVI),index of systemic vascular resistance(SVRI),global end-diastolic volume index(GEDVI),and cardiac function index(CFI) were monitored by transpulmonary thermodilution technique (PiCCO). ResultsPLR1 significantly increased SVI by (20.54±9.63)%,CI by (20.57±9.89)%,MAP by (7.64±5.77)%,and CVP by (25.83±23.39)%. As the dose of norepinephrine increased,SVI was increased by (16.97±9.06)%,CI by (16.78±8.39)%,GEDVI by (9.08±4.47)%,MAP by (28.07±12.48)%,and CVP by (7.86±8.52)%. PLR2 increased SVI by (13.74±8.79)%,CI by (13.79±9.08)%,MAP by (2.93±5.06)%,and CVP by (13.36±14.74)%. The PLR2 and the dose increase of norepinephrine augmented SVI to a significantly lesser extent than the PLR1 performed at baseline (both P<0.05). However,SVI increased by <10% in 6 patients while the baseline PLR was positive in these patients. ConclusionIn septic patients with a positive PLR at baseline,norepinephrine increases cardiac preload and cardiac output and influences the fluid responsiveness.
Objective To analyze the influence of COPD on the structure and function of left ventricular. Methods Sixty-nine COPD patients ( mean age: 69. 0 ±7. 8 yrs) and forty healthy controls ( mean age: 67. 8 ±7. 6 yrs) were enrolled in this study. Both groups underwent Doppler echocardiography.Heart rate ( HR) were recorded. Left ventricular end-diastolic volume ( LVEDV) , left ventricular enddiastolic diameter ( LVEDD) , interventricular septum( IVS) , stroke volume ( SV) , and cardiac output ( CO)were measured. The changes of left ventricular were compared between the COPD patients and the healthy controls, and also between the COPD patients with or without chronic cor pulmonale. Results Compared with the healthy controls, movement range of IVS, LVEDD, LVEDV, and SV reduced significantly ( P lt;0. 05) , and HR raised significantly in the COPD patients ( P lt; 0. 05) . CO had no significant difference between two groups ( P gt;0. 05) . Sub-group analysis indicated that the thickness and movement range of IVSwere greater in the patients with cor pulmonale secondary to COPD than those without cor pulmonale ( P lt;0. 05) . Conclusions In COPD patients, left ventricular chamber size decreases, and left ventricular systolic function is impaired. Left ventricular function is impaired more severe in cor pulmonale secondary to COPD than COPD without cor pulmonale.
Objective To investigate the effects of different levels of intra-abdominal pressure ( IAP) on respiration and hemodynamics in a porcine model of acute lung injury( ALI) .Methods A total of 8 domestic swine received mechanical ventilation. Following baseline observations, oleic acid 0. 1mL/kg in 20mL of normal saline was infused via internal jugular vein. Using a nitrogen gas pneumoperitongum, the IAP increased from0 to 15 and 25mmHg, and the groups were named IAP0 , IAP15 and IAP25 , respectively. During the experimental period, hemodynamic parameters including heart rate ( HR) , cardiac output ( CO) , mean arterial pressure( MAP) , central venous pressure( CVP) , intrathoracic blood volume index( ITBVI) and so on were obtained by using thermodilution technique of pulse induced continuous cardiac output( PiCCO) . The esophageal pressure( Pes) was dynamicly monitored by the esophageal catheter. Results Pes and peak airway pressure( Ppeak) increased and static lung compliance( Cstat) decreased significantly in IAP15 and IAP25 groups compared with IAP0 group( all P lt;0. 01) . Transpulmonary pressure( Ptp) showed a downward trend( P gt;0. 05) . PO2 and oxygenation index showed a downward trend while PCO2 showed a upward trend ( P gt;0. 05) . HR and CVP increased significantly, cardiac index( CI) and ITBV index decreased significantly ( all P lt;0. 05) ,MAP didn′t change significantly( P gt;0. 05) . The changes in Pes were negatively correlated with the changes in CI( r = - 0. 648, P = 0. 01) . Conclusion In the porcine model of ALI, Pes increases because of a rise in IAP which decreased pulmonary compliance and CI.
Objective To study the influence of low-tidal volume and positive end expiratory pressure (PEEP) protective ventilation on cardiac output volume in elderly patients under general anesthesia. Methods From August 2012 to July 2014, 60 elderly patients undergoing selective surgery were divided into three groups with 20 patients in each. Group A was treated with conventional ventilation: tidal volume at 8 mL/kg, PEEP at 0 cm H2O (1 cm H2O=0.098 kPa); group B was treated with a tidal volume of 6 mL/kg and a PEEP of 5 cm H2O; group C was treated with a tidal volume of 6 mL/kg and a PEEP of 8 cm H2O. We then observed and analyzed the blood pressure, heart rate, cardiac output, arterial blood gas and airway mean pressure before induction of anesthesia (T0), 15 minutes of mechanical ventilation after the induction of anesthesia (T1), 60 minutes after anesthesia induction (T2), and 15 minutes after tracheal extubation (T3). Results In all the three groups, the mean arterial pressure and cardiac output were stable. In group B and C, central venous pressure increased significantly, the mean airway pressure and lung compliance increased, and the arterial oxygen branch pressure also increased significantly (P < 0.05). Conclusion Low-tidal volume combined with 5-cm H2O or 8-cm H2O positive end expiratory pressure lung-protective ventilation had a small influence on the cardiac output of elderly patients under anesthesia, which can be safely used.
ObjectiveTo evaluate the feasibility to use ultrasonic cardiac output monitoring (USCOM) for patients after coronary artery bypass grafting. MethodsClinical data of 32 patients undergoing off-pump coronary artery bypass grafting in General Hospital of Shenyang Military Region between April and June 2013 were retrospectively analyzed. There were 17 male and 15 female patients with their age of 46-76 (63.2±7.6) years. USCOM and pulmonary artery catheterization (PAC) were used to measure cardiac output (CO) synchronously,and the results were compared between USCOM and PAC. ResultsSixty-four pairs of data were collected from those 32 patients. No adverse event was observed with either USCOM or PAC. Mean CO was 4.27±0.92 L/min with USCOM and 4.49±0.75 L/min with PAC respectively,which were not statistically different (P=0.12) but significantly correlated (r=0.84,P<0.001). ConclusionThere is close correlation between USCOM and PAC for CO measurement. USCOM can not only measure CO accurately,but also has the advantages of being noninvasive,easy to perform and low cost.