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Objective:To compare the difference of low-level assisted ventilation and T-piece method on respiratory mechanics of patients with invasive mechanical ventilation during spontaneous breathing trial (SBT) within 3 days before extubation.Methods:A retrospective observational study was conducted. Twenty-five patients with difficulty in weaning or delayed weaning from invasive mechanical ventilation who were admitted to department of critical care medicine of the First Affiliated Hospital of Guangzhou Medical University from December 2018 to June 2020, and were in stable condition and entered the weaning stage after more than 72 hours of invasive mechanical ventilation were studied. A total of 119 cases of respiratory mechanical indexes were collected, which were divided into the low-level assisted ventilation group and the T-piece group according to the ventilator method and parameters used during the data collection. The different ventilation modes related respiratory mechanics indexes such as the esophageal pressure (Pes), the gastric pressure (Pga), the transdiaphragmatic pressure (Pdi), the maximum Pdi (Pdimax), Pdi/Pdimax ratio, the esophageal pressure-time product (PTPes), the gastric pressure-time product (PTPga), the transdiaphragmatic pressure-time product (PTPdi), the diaphragmatic electromyography (EMGdi), the maximum diaphragmatic electromyography (EMGdimax), PTPdi/PTPes ratio, Pes/Pdi ratio, the inspiratory time (Ti), the expiratory time (Te) and the total time respiratory cycle (Ttot) at the end of monitoring were recorded and compared between the two groups.Results:Compared with the T-piece group, Pes, PTPes, PTPdi/PTPes ratio, Pes/Pdi ratio and Te were higher in low-level assisted ventilation group [Pes (cmH 2O, 1 cmH 2O = 0.098 kPa): 2.84 (-1.80, 5.83) vs. -0.94 (-8.50, 2.06), PTPes (cmH 2O·s·min -1): 1.87 (-2.50, 5.93) vs. -0.95 (-9.71, 2.56), PTPdi/PTPes ratio: 0.07 (-1.74, 1.65) vs. -1.82 (-4.15, -1.25), Pes/Pdi ratio: 0.17 (-0.43, 0.64) vs. -0.47 (-0.65, -0.11), Te (s): 1.65 (1.36, 2.18) vs. 1.33 (1.05, 1.75), all P < 0.05], there were no significant differences in Pga, Pdi, Pdimax, Pdi/Pdimax ratio, PTPga, PTPdi, EMGdi, EMGdimax, Ti and Ttot between the T-piece group and the low-level assisted pressure ventilation group [Pga (cmH 2O): 6.96 (3.54,7.60) vs. 7.74 (4.37, 11.30), Pdi (cmH 2O): 9.24 (4.58, 17.31) vs. 6.18 (2.98, 11.96), Pdimax (cmH 2O): 47.20 (20.60, 52.30) vs. 29.95 (21.50, 47.20), Pdi/Pdimax ratio: 0.25 (0.01, 0.34) vs. 0.25 (0.12, 0.41), PTPga (cmH 2O·s·min -1): 7.20 (2.54, 9.97) vs. 7.97 (5.74, 13.07), PTPdi (cmH 2O·s·min -1): 12.15 (2.95, 19.86) vs. 6.87 (2.50, 12.63), EMGdi (μV): 0.05 (0.03, 0.07) vs. 0.04 (0.02, 0.06), EMGdimax (μV): 0.07 (0.05, 0.09) vs. 0.07 (0.04, 0.09), Ti (s): 1.20 (0.95, 1.33) vs. 1.07 (0.95, 1.33), Ttot (s): 2.59 (2.22, 3.09) vs. 2.77 (2.35, 3.24), all P > 0.05]. Conclusions:When mechanically ventilated patients undergo SBT, the use of T-piece method increases the work of breathing compared with low-level assisted ventilation method. Therefore, long-term use of T-piece should be avoided during SBT.
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Objective:To understand the function of diaphragm and analyze the clinical factors affecting the function of diaphragm by measuring twitch tracheal pressure (TwPtr) in patients with mechanical ventilation and in the weaning phase.Methods:Patients with more than 48 hours of invasive mechanical ventilation admitted to the department of critical care medicine of the First Affiliated Hospital of Guangzhou Medical University from December 2015 to March 2017 were enrolled. After the patient entered the weaning stage, TwPtr of patients was monitored by two-way non repetitive automatic respiratory trigger device, the effects of duration of mechanical ventilation, severe pulmonary infection, sedative application and chronic obstructive pulmonary disease (COPD) on weaning were analyzed.Results:A total of 62 patients were included, of which 45 were male and 17 were female. The average age was (66.8±11.7) years old. Twenty-three cases had severe pneumonia. The absolute value of TwPtr in severe pneumonia group was lower than that in non-severe pneumonia group [cmH 2O (1 cmH 2O = 0.098 kPa): 10.40±5.81 vs. 14.35±5.22, P = 0.021]. However, there was no significant difference in the duration of mechanical ventilation between the severe pneumonia group and non-severe pneumonia group [days: 26 (17, 43) vs. 15 (11, 36), P = 0.091]. In 62 patients with mechanical ventilation, there was a negative correlation between TwPtr and duration of mechanical ventilation ( r = 0.414, P = 0.002), there was also a negative correlation between the duration of mechanical ventilation and TwPtr after the assessment of diaphragm function ( r = 0.277, P = 0.039). There was a linear relationship between TwPtr and sedatives ( r = 0.220, P = 0.040), but there was no correlation between TwPtr and COPD ( r = -0.178, P = 0.166). Conclusions:For patients in the weaning stage of mechanical ventilation, severe pulmonary infection is one of the factors that affect the diaphragm dysfunction. There is a certain correlation between the diaphragm dysfunction and the use of sedatives.
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ObjectiveTo explore the effect of prone position ventilation (PPV) on respiratory mechanics and prognosis in patients with acute respiratory distress syndrome (ARDS) concurrent with interstitial lung disease (ILD). Methods The data of 36 severe ARDS patients admitted to Department of Critical Care Medicine of the First Affiliated Hospital of Guangzhou Medical University from February 2013 to January 2015, were retrospectively analyzed. They were then divided into two groups according to the presence of ILD or not. The changes in respiratory mechanics and oxygenation indexes were compared before and after PPV treatment in all the patients. Kaplan-Meier method was applied to draw the 60-day survival curves of both groups.Results There were 17 cases with ILD among these 36 severe ARDS patients.① No significant difference was found in baseline data between ILD group and non-ILD group.② Respiratory mechanics and oxygenation pre-PPV and post-PPV: compared with pre-PPV, oxygenation index (PaO2/FiO2, mmHg, 1 mmHg = 0.133 kPa) post-PPV was significantly increased in both groups [ILD group : 132.0 (93.5, 172.0) vs. 118.7 (92.0, 147.8); non-ILD group: 126.1 (100.9, 170.0) vs. 109.2 (89.0, 135.0), bothP 0.05], and Crs was lower after PPV treatment in both groups, but without significant difference [non-ILD group: 22.7 (15.2, 27.1) vs. 24.3 (15.9, 48.9); ILD group: 16.2 (12.8, 25.6) vs. 18.9 (12.7, 27.3), bothP> 0.05].④ The 60-day mortality in ILD group was significantly higher than that in non-ILD group [88.2% (15/17) vs. 57.9% (11/19),P = 0.047). It was shown by Kaplan-Meier curves that 60-day survival patients in ILD group was significantly lower than those in non-ILD group (χ2 = 5.658,P = 0.017). Conclusions PPV can improve oxygenation in severe ARDS. Compared with non-ILD group, though the compliance of respiratory system in ILD group is increased during PPV, long-term effect is better in non-ILD group.
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Objective To investigate the effects of sepsis bundles in China.Method An observational study of 43 patients with severe pneumonia and septic shock admitted to the respiratory intertive care unit(1/11/2006-31/12/2007)was carried out.The selection criteria were in accordance with criteria set by International Conference On Sepsis in 2001.Implementation of 6 hours and 24 hours sepsis bundles was divided into 3 continu-ous phases consisting of education,trial,and application phase.A cohort of 43 patients with matched disease his-tory(1/1/2004-31/10/2006)was enrolled as control group.The percentages for categorical variables and mean±SD for continuous variables were reported.Chi-Square test.unpaired Student's t -test.paired-samples t test,univariate and multivariate logistic regression models were used.Statistical significance was defined as P＜0.05.Results There were very little significant differences in basic characteristics of patients between the two groups.Compared with control group,the differences in serrum lactate,fluid resuscitation and fluid volume infused within 6 hours and blood glucose control in shock subgroup were significant(P values were 0.024,0.009,0.045,and 0.000,respectively).Compared with control group,the differences in respiratory rate and oxygenation index of bundles group at 72 hours later were significant(P values were 0.033 and 0.041,respectively).Compared with control group,the differences in APACHE Ⅱ score and predicted mortality in shock subgroup of bundles were sig-nificant(P values were 0.017 and 0.040,respectively).Compared with control group,the reduction in absolute mortality was 23.30% in bundles group(P=0.019).Conclusions Implementation of sepsis bundles con-tributes noticeably to the significant reduction in mortality of patients with severe pneumonia and septic shock.