ObjectiveTo investigate the effect of noninvasive ventilation (NIV) in patients with myasthenic crisis after thymectomy. Methods31 myasthenic crisis patients after thymectomy who initially used NIV,admitted in the First Affiliated Hospital of Guangzhou Medical University between January 2011 and June 2013,were analyzed retrospectively.They were assigned to two groups according to the successful application of NIV or not,with 13 patients in the NIV success group and 18 patients in the NIV failure group.The related factors including gender,age,APACHEⅡ score when admitted to ICU,the results of blood gas analysis before NIV,thymoma or not,the history of myasthenic crisis,the history of chronic lung disease,and minute ventilation accounted for the largest percentage of predicted value (MVV%pred)were analyzed. ResultsThere were no significant differences in age,gender,or APACHEⅡ score between two groups (P>0.05).The PaCO2 in the NIV success group was lower than that in the NIV failure group.The preoperative MVV%pred in the NIV success group was higher than that in the NIV failure group.There were no significant differences between two groups in pH,PO2,thymoma or not,the history of myasthenic crisis,or the history of chronic lung disease (P>0.05).If using the 45 mm Hg as the cut-off value of PaCO2 and 60% as the cut-off value of MVV%pred,the incidence of PaCO2<45 mm Hg and the incidence of MVV%pred>60% were higher in the NIV success group than those in the NIV failure group (84.6% vs.33.3%, P<0.05;100% vs. 55.6%,P<0.05).Logistic regression analysis revealed that PaCO2<45 mm Hg was an independent influence factor for successful application of NIV in patients with myasthenic crisis after thymectomy. ConclusionPaCO2<45 mm Hg can be a predictor of successful application of NIV in patients with myasthenic crisis after thymectomy.For the patients underwent NIV whose PaCO2<45 mm Hg or MVV%pred<60%,the clinician should predict the possibility of failure and prepared for intubation.
ObjectiveTo investigate the clinical significance of cardiac function index (CFI) and global ejection fraction (GEF), derived from single-indicator transpulmonary thermodilution technique, in assessment of cardiac function in critically ill patients. MethodsA prospective clinical observational study was conducted in the Intensive Care Unit of the First Affiliated Hospital of Guangzhou Medical University. Between January 2012 and December 2012, 39 patients who underwent PiCCO monitoring were recruited, including 18 cases with left ventricular systolic dysfunction and 21 cases without left ventricular systolic dysfunction. Both groups underwent transpulmonary thermodilution measurements and transthoracic cardiac ultrasonography. Pearson correlation analysis was conduced to assess the correlation between left ventricular ejection fraction (LVEF) and CFI and GEF. ROC curve was established to calculate the predicted threshold of CFI and GEF for diagnosing cardiac insufficiency. ResultsLVEF was significantly correlated with CFI and GEF (r=0.553, P < 0.005; r=0.468, P < 0.005). The area under ROC curve of CFI, GEF and LVEF for diagnosing cardiac insufficiency was 0.885, 0.862 and 0.903, respectively (P > 0.05 for comparison). The cut-off value of CFI for predicting cardiac insufficiency was 4.25/min, with a sensitivity of 77.8% and a specificity of 88.9%. The cut-off value of GEF for predicting cardiac dysfunction was 19.5/min, with a sensitivity of 88.9% and a specificity of 66.7%. ConclusionCFI and GEF measured by transpulmonary thermodilution correlate well with LVEF assessed by transthoracic echocardiography, both can be used for assessment of left ventricular systolic function.
ObjectiveTo evaluate the value of stroke volume variation (SVV) and intrathoracic blood volume index (ITBVI) to predict fluid responsiveness in mechanically ventilated septic shock patients with spontaneous breathing. MethodsA prospective observational study was conducted in the Department of Critical Care Medicine of the First Affiliated Hospital of Guangzhou Medical University. Fluid resuscitation data was collected in septic shock patients who received PiCCO monitoring from June 2013 to June 2014. Transpulmonary thermodilution data were collected before and after fluid resuscitation, including cardiac index (CI), SVV, ITBVI, and central venous pressure (CVP). Seventeen patients were defined as responders by an observed increase of≥15% in the cardiac index (CI) after fluid resuscitation, 12 patients were defined as non-responders. Pearson correlation between changes of CI (ΔCI) and SVV, ITBVI, CVP was established. Area under the receiver operating characteristic (ROC) curve of SVV, ITBVI and CVP was calculated for predicting fluid responsiveness. ResultsBaseline CI and ITBVI were significantly lower in the responders (P < 0.05).There was no significant difference in baseline SVV between the responders and the non-responders (P > 0.05). A significant correlation was found between baseline ITBVI andΔCI (r=-0.593, P < 0.001), but no significant correlation between SVV andΔCI (r=0.037, P=0.847) or CVP andΔCI (r=0.198, P=0.302). The area under ROC curve of SVV, ITBVI and SVV for predicting fluid responsiveness was 0.640 (P=0.207), 0.865 (P=0.001), and 0.463 (P=0.565), respectively. The cut-off value of ITBVI for predicting fluid responsiveness was 784 mL/m2 with a sensitivity of 100.0% and a specificity of 70.6%. ConclusionIn mechanically ventilated septic shock patients with spontaneous breathing, ITBVI may be a valuable indicator in predicting fluid responsiveness compared with SVV.
Objective To investigate the effect of prone position ventilation (PPV) on hemodynamics in patients with interstitial lung disease (ILD) concurrent with acute respiratory distress syndrome (ARDS) or not. Methods Severe ARDS patients received PPV treatment in intensive care unit from 2013 to 2015 were retrospectively analyzed. Pulse index continuous cardiac output (PiCCO) monitoring indices were compared 2h before PPV (PPV-2), in-PPV (PPVmean) and 2h after turn back to supine position (PPV+2), including mean arterial pressure (MAP), cardiac index (CI), intrathoracic blood volume index (ITBVI), etc. Heart function, liver function, renal function, coagulative function were compared before and after all the PPV treatment. Results Thirty-six severe pulmonary ARDS patients were recruited. Norepinephrine (NE) dose was (0.14±0.10) μg·kg-1·min-1 and lactate concentration was (1.70±0.57) mmol/L before PPV. CI in all the patients was increased [(4.06±0.95) L·min-1·m-2 vs. (3.98±1.05) L·min-1·m-2, P > 0.05) and central venous oxygen saturation, ITBVI [(76.94±8.94)% vs. (70.67±8.23)%, (982.17±245.87) mL/m2 vs. (912.97±177.65) mL/m2, P < 0.05)] were significantly increased compared with PPV-2, while heart rate (HR), MAP, urine volume were decreased (P > 0.05). The patients were divided into an ILD group (n=17) andanon-ILD group (n=19),and no significant differences were found in baseline data between two groups. Compared with PPV-2, MAP was significant decreased at PPV+2 [(85.44±10.84) mm Hg vs. (89.21±10.92) mm Hg, P < 0.05) in the ILD group. Compared with PPVmean, CI was obviously declined at PPV+2 in the ILD group. Activated partial thromboplastin time was increased [(67.04±97.52)s vs. (41.24±8.72) s, P < 0.05] and BUN was higher [(10.64±4.95) μmol/L vs. (8.18±3.88) μmol/L, P < 0.05] in the ILD group, while no significant difference was found in the non-ILD group. Conclusion PPV will not affect cardiac output in severe ARDS patients with ILD. It can increase venous return and improve tissue perfusion, but the perfusion of the abdomen organ need to be monitored cautiously.