Efficacy of Goal-Directed Therapy Using Bioreactance Cardiac Output Monitoring after Valvular Heart Surgery

PURPOSE: We compared the efficacy of postoperative hemodynamic goal-directed therapy (GDT) using a pulmonary artery catheter (PAC) and bioreactance-based noninvasive cardiac output monitoring (NICOM) in patients with atrial fibrillation undergoing valvular heart surgery. MATERIALS AND METHODS: Fifty eight patients were randomized into two groups of GDT with common goals to maintain a mean arterial pressure of 60-80 mm Hg and cardiac index > or =2 L/min/m2: the PAC group (n=29), based on pulmonary capillary wedge pressure, and the NICOM group (n=29), based on changes in stroke volume index after passive leg raising. The primary efficacy variable was length of hospital stay. Secondary efficacy variables included resource utilization including vasopressor and inotropic requirement, fluid balance, and major morbidity endpoints. RESULTS: Patient characteristics and operative data were similar between the groups, except that significantly more patients underwent double valve replacement in the NICOM group. The lengths of hospital stay were not different between the two groups (12.2+/-4.8 days vs. 10.8+/-4.0 days, p=0.239). Numbers of patients requiring epinephrine (5 vs. 0, p=0.019) and ventilator care >24 h (6 vs. 1, p=0.044) were significantly higher in the PAC group. The PAC group also required significantly larger amounts of colloid (1652+/-519 mL vs. 11430+/-463 mL, p=0.004). CONCLUSION: NICOM-based postoperative hemodynamic GDT showed promising results in patients with atrial fibrillation undergoing valvular heart surgery in terms of resource utilization.

The significance of non invasive cardiac output monitoring system on evaluating circulatory and respiratory function in pig with acute respiratory distress syndrome / 中华危重病急救医学

Objective To investigate the effect of non invasive cardiac output monitoring(NICO)system in pig model with acute respiratory distress syndrome(ARDS),and to provide experimental basis for clinical application. Methods Eleven anaesthetized and ventilated ARDS male pig models were induced by intravenously infusing 0.2 mL/kg oleic acid. Lung recruitment was condocted by pressure control ventilation on pigs with ARDS. The optimal positive end-expiratory pressure(PEEP)was determined by optimal dead space fraction〔the ratio of dead space to tidal volume(VD/VT)〕. Cardiac output(CO)was determined by NICO,the respiratory function was monitored, and the VD/VT,dynamic compliance(Cdyn),oxygenation index(PaO2/FiO2),the volume of alveolar ventilation(Valv) and arterial blood oxygen saturation(SaO2)were recorded before infusing oleic acid,after stabilization of ARDS model and at optimal PEEP level,and the intrapulmonary shunt fraction(Qs/Qt)was calculated. CO was also determined by application of pulse indicated continuous cardiac output(PiCCO),and the linear regression analysis between CO determined by NICO and CO determined by PiCCO was conducted. Results Seven experimental ARDS pigs model were successfully established. The optimal PEEP identified by the lowest VD/VT method was(15.71±1.80)cmH2O (1 cmH2O=0.098 kPa). Compared with before infusing oleic acid,VD/VT and Qs/Qt after stabilization of ARDS model were significantly increased〔VD/VT:(72.29±8.58)% vs.(56.00±11.06)%,Qs/Qt:(21.04±15.05)%vs.(2.00±1.32)%,both P0.05). There was linear correlation between CO determined by NICO and CO determined by PiCCO(r2=0.925,P<0.001). Conclusions NICO technique provides a useful and accurate non invasive estimation of CO and respiratory function.VD/VT provided by NICO can titrate the optimal PEEP in patients with ARDS.

The Effect of the Lithotomy-Trendelenburg Position on Respiratory and Hemodynamic Changes during General Anesthesia / 대한마취과학회지

BACKGROUND: The effects of Trendelenburg positions used to expose the surgical field may induce intraoperative hemodynamic and respiratory changes that complicate anesthetic management. This study was performed to evaluate the effects of the lithotomy-Trendelenburg position on respiratory and hemodynamic changes with time passage during general anesthesia. METHODS: Twenty patients undergoing anorectal surgery with general anesthesia were studied. Hemodynamic and respiratory parameters were measured before the lithotomy-Trendelenburg position (L) and 3 min (LT3), 6 min (LT6), 12 min (LT12), 30 min (LT30) and 60 min (LT60) after the 30 degree Trendelenburg position. The cardiac index (CI), stroke volume (SV), systemic vascular resistance (SVR), airway resistance (Raw) and dynamic compliance (Cdyn) were measured by a non-invasive cardiac output monitor. RESULTS: Central venous pressure and peak inspiratory pressure were markedly increased from the lithotomy to the lithotomy-Trendelenburg position. Heart rate was slightly increased while SV, CI, SVR and MAP were decreased. No significant changes of the SV or CI were observed during surgery. The Cdyn was significantly decreased. CONCLUSIONS: The steep lithotomy-Trendelenburg position induces moderate adverse hemodynamic and respiratory effects in healthy patients. These findings indicate the need for more active hemodynamic and respiratory monitoring in patients with a compromised cardiopulmonary function.