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The "timed inspiratory effort" (TIE) index, a new predictor of weaning outcome, normalizes the maximal inspiratory pressure with the time required to reach this value up to 60 s, incorporating the time domain into the assessment of inspiratory muscle function. The objective of this study was to determine whether the TIE predicts successful extubation at a similar rate as the T-piece trial with less time required. A non-inferiority randomized controlled trial was performed with ICU subjects eligible for weaning. The participants were allocated to the TIE or the T-piece groups. The primary outcome was successful weaning, and the main secondary outcome was ICU mortality. Eighty participants of each group were included in the final analysis. Time from the start of a successful test to effective extubation was significantly lower in the TIE group than in the T-piece group, 15 (10 to 24) vs 55 (40 to 75) min, P<0.001. In the Kaplan-Meier analysis, no significant differences were found in successful weaning (79.5 vs 82.5%, P=0.268) or survival rate (62.9 vs 53.8%, P=0.210) between the TIE and T-piece groups at the 30th day. In this preliminary study, the TIE index was not inferior to the T-piece trial as a decision-making tool for extubation and allowed a reduction in the decision time.
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Objective:To determine the risk factors of extubation failure and its effect on the prognosis of patients who had successfully passed a spontaneous breathing trial (SBT).Methods:The clinical data of patients with mechanical ventilation more than 24 hours who passed SBT admitted to department of intensive care unit (ICU) of First Hospital of Qinhuangdao from November 2018 to November 2019 were retrospectively analyzed. According to the outcome of weaning within 48 hours after weaning, patients were divided into weaning success group and weaning failure group. The baseline data, the presence of basic cardiopulmonary diseases, B-type natriuretic peptide (BNP), fluid balance, albumin and hemoglobin within 24 hours before weaning, the time of mechanical ventilation before weaning, rapid shallow breathing index (RSBI) during SBT, oxygenation index, cough peak flow at the end of SBT, and prognostic indicators were collected. The outcome of weaning was taken as the dependent variable, and the observation factors were taken as the independent variable for univariate analysis. The factors with statistical significance in univariate analysis were analyzed by binary Logistic regression to determine the influencing factors of weaning failure.Results:Of the 204 patients, 167 (81.9%) were successfully weaned, and 37 (18.1%) failed. Compared with the weaning success group, the total duration of mechanical ventilation and the length of ICU stay in the weaning failure group were significantly longer [days: 13.0 (7.5, 23.5) vs. 5.0 (3.0, 8.0), 17.0 (12.5, 31.0) vs. 10.0 (6.0, 15.0), both P < 0.01], and the tracheotomy rate and mortality were significantly higher (32.4% vs. 0%, 51.4% vs. 0%, both P < 0.01). Univariate analysis showed that there were significant differences in age, proportion of patients with cardiopulmonary diseases, BNP and cough peak flow between weaning failure group and weaning success group [age (years old): 70.65±15.78 vs. 62.69±15.82, cardiopulmonary diseases: 62.2% vs. 24.6%, BNP (ng/L): 416.87 (32.70, 1 225.80) vs. 45.36 (10.00, 273.60), cough peak flow (L/min): 59.89±9.06 vs. 83.84±16.52, all P < 0.01]. However, there were no significant differences in gender, acute physiology and chronic health evaluationⅡ (APACHEⅡ) at admission, mechanical ventilation time before weaning, albumin, hemoglobin, oxygenation index, RSBI and fluid balance 24 hours before weaning between weaning failure group and weaning success group [male: 51.4% vs. 68.3%, APACHEⅡ: 16.70±6.65 vs. 15.67±6.28, mechanical ventilation time before weaning (days): 6.0 (2.5, 11.0) vs. 5.0 (3.0, 8.0), albumin (g/L): 27.78±4.15 vs. 27.76±4.46, hemoglobin (g/L): 102.43±15.80 vs. 100.61±17.19, oxygenation index (mmHg, 1 mmHg = 0.133 kPa): 359.33±79.83 vs. 365.75±78.23, RSBI (times·L -1·min -1): 50.73±24.97 vs. 46.76±15.53, positive fluid balance: 70.3% vs. 69.5%, all P > 0.05]. The results of binary Logistic regression analysis showed that age ≥ 75 years old [odds ratio ( OR) = 3.099, 95% confidence interval (95% CI) was 1.003-9.574, P = 0.049], presence of cardiopulmonary diseases ( OR = 3.599, 95% CI was 1.126-11.498, P = 0.031), BNP within 24 hours before weaning ( OR = 1.002, 95% CI was 1.000-1.003, P = 0.005) were the risk factors of extubation failure, while cough peak flow at the end of SBT was the protective factor ( OR = 0.869, 95% CI was 0.823-0.917, P = 0.000). Conclusions:For patients who had successfully passed SBT, age ≥ 75 years old, the presence of cardiopulmonary diseases and an increased level of BNP within 24 hours were the risk factors of extubation failure. In addition, the higher the cough peak flow at the end of SBT, the lower the risk of weaning failure will be.
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Objective To study the predictive value of lung ultrasound score(LUS) on the extubation success rate in the patients with mechanical ventilation for early identifying the high risk patients with extubation failure and guiding the sequential therapy after extubation.Methods The prospective study method was adopted.Eighty-one cases with mechanical ventilation exceeding 48 h and successfully passing the spontaneous breathing trial(SBT) in EICU were selected.The bedside LUS evaluation was conducted before extubation.The cases were divided into the two groups according to whether successfully weaning.And the LUS differences before extubation were compared between the two groups.The receiver operating characteristic(ROC) curve was used to evaluate the predictive efficiency for extubation failure.Results The age and sex had no statistical difference between the two groups(P＞0.05).In included 81 cases,27 cases were failed to extubation and appeared different degrees of respiratory distress sign:respiratory rate(RR) increase,heart rate(HR) increase,SpO2 decrease,etc.,which needed non-invasive mechanical ventilation or high flow nasal cannula oxygen for alleviating respiratory difficulty.In the extubation failure group,10 cases were ineffective by above treatment and then needed reintubation.One case died within 24 h after extubation.Fifty-four cases succeeded in weaning and extubation.The LUS score was positively correlated with RR and PaCO2 (r=0.43,0.62;P＜0.05) and negatively correlated with SpO2 and PaO2(r=-0.76,-0.58;P＜0.05),while it was not correlated with HR and pH value(r=0.15,0.02,P＞0.05).The area under the ROC curve (AUC) of LUS score was 0.90(95％CI:0.84-0.95),it could be regarded that the accuracy of LUS for predicting extubation failure rate was stable,its sensitivity was 0.84 and specificity was 0.80.The diagnostic cutoff value was 15.00,if the LUS score exceeding 15 points,the extubation failure rate was significantly increased.Conclusion The LUS score has clinical application value for assessing the extubation success rate in the patients with mechanical ventilation.The patients with high risk of extubation failure can be early identified by the LUS score,which can guide the sequential therapy after extubation.
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Objective To investigate the predictive value of left ventricular diastolic function on mechanical ventilation weaning in patients with left ventricular ejection fraction (LVEF) > 0.50.Methods A retrospective case control study was conducted. Sixty-five patients with LVEF > 0.50 undergoing mechanical ventilation for more than 48 hours admitted to surgery intensive care unit (ICU) of China-Japan Friendship Hospital from June 2014 to December 2016 were enrolled. The clinical data and parameters of echocardiography before spontaneous breathing trial (SBT) were collected. The possible relationship between left ventricular diastolic function and the results of weaning was analyzed according to analysis of blood flow filling parameters of mitral valve orifice. According to the grading standard of left ventricular diastolic function, the patients were divided into normal, mild (level 1) and moderate to severe (level 2-3) groups, and the outcomes of weaning were compared among the groups. Then patients were also divided into two groups of weaning successfully and weaning failure, and the clinical data and left ventricular diastolic function parameters of patients were compared between the two groups. The predictive value of left ventricular diastolic function on results of weaning was evaluated with receiver operating characteristic curve (ROC).Results Sixty-five patients were enrolled and 28 patients (43.1%) failed weaning, 22 patients failed the first SBT and 6 required reintubation within 48 hours, 31 of the patients presented normal left ventricular diastolic function, 9 of patients presented mild diastolic dysfunction, and 25 of them presented moderate to severe diastolic dysfunction. So with the gradual increase of the severity of diastolic dysfunction, the rate of weaning failure was gradually increased, which was 16.1%, 44.6% and 76.0% respectively (χ2 = 20.240,P = 0.001). Patients who failed weaning presented evidence of increased left ventricular filling pressures at pre-SBT, by demonstrating decreased deceleration time of E (DTE, s: 180.4±5.1vs. 196.8±4.0,t = 2.567,P = 0.013), increased left ventricular mitral valve diastolic early and late filling velocity ratio (E/A: 1.47±0.08 vs. 1.14±0.05, t = 3.827,P = 0.000), increased lateral, septal and averaged left ventricular mitral valve diastolic early velocity and maximal velocity of mitral annulus in early diastolic velocity ratio (E/Em: 10.26±0.52 vs. 7.28±0.41,t = 4.535, P = 0.000; 10.08±0.58 vs. 8.16±0.40,t = 2.797,P = 0.007; 10.17±0.48比7.72±0.35,t = 4.231,P = 0.000), and the rapid shallow breathing index (RSBI) was also increased significantly (61.7±3.6 vs. 50.6±2.7,t = 2.507, P = 0.015). It was shown by ROC curve analysis that the basic left ventricular diastolic function at pre-SBT had the diagnostic performance in predicting the outcome of weaning from mechanical ventilation, especially E/A and lateral E/Em. Pre-SBT values of E/A greater than 1.2 and lateral E/Em greater than 7.9 predicted weaning failure with an area under the ROC curve (AUC), sensitivity, and specificity of 0.81±0.06 and 0.85±0.06, 82.6% and 91.3%, 81.4% and 80.7%, respectively, and the AUC was higher than RSBI (0.70±0.07). The AUC of combination of E/A > 1.2 and lateral E/Em > 7.9predicting weaning failure was 0.86±0.05 with a sensitivity of 78.3% and a specificity of 93.6%.Conclusions The results suggest that left ventricular diastolic dysfunction is significantly associated with weaning outcome in critical patients with LVEF > 0.50. The combination of E/A ratio greater than 1.2 and E/Em ratio greater than 7.9 may identify patients at high risk of weaning failure.
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Objective To investigate the value of N-terminal pro-B type natriuretic peptide (NT-proBNP) in predicting the outcome of spontaneous breathing trial (SBT) in ventilated elderly renal dysfunction patients. Methods The clinical data of patients who received mechanical ventilation in the Department of Critical Care Medicine of the First Affiliated Hospital of Guangzhou Medical University, Guangzhou Institute of Respiratory Disease from January 2011 to December 2014 were analyzed retrospectively. AU the patients conformed to the following criteria: age > 65 years, endogenous creatinine clearance rate (CCr) 72 hours and undergone at least one SBT. The patients were assigned to a SBT success group and a SBT failure group according to the outcome of first SBT. The following factors were recorded: gender, age, the underlying disease [chronic obstructive pulmonary disease (COPD), heart failure (HF) and others], body mass index (BMI), serum pre-albumin (pre-ALB), and acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score, CCr and the concentration of the plasma NT-proBNP before SBT. Receiver operator characteristic curve (ROC) was plotted, and the predict value of NT-proBNP for the outcome of SBT in elder patients with kidney dysfunction was determined. Results A total of 58 patients with complete data were enrolled, with 41 cases in SBT success group, and 17 in SBT failure group. There were no significant differences in gender [male/female (cases): 26/15 vs. 13/4, χ2 = 0.930, P = 0.335], age (years: 70.2±7.4 vs. 74.6±10.1, t = 0.833, P = 0.339), the stratification of underlying diseases [COPD/HF/COPD+HF/others (cases): 15/9/13/4 vs. 7/3/5/2, χ2 = 0.242, P = 0.971], BMI (kg/m2: 25.2±11.3 vs. 27.4±6.43, t = 1.038, P = 0.221), pre-ALB (mg/L: 201.0±13.2 vs. 189.0±7.6, t = 0.688, P = 0.519), and APACHE Ⅱ score (12.2±3.2 vs. 13.5±6.3, t = 1.482, P = 0.147) and CCr (mL·min-1·1.73 m-2: 51.3±7.7 vs. 54.2±6.4, t = 0.711, P = 0.487) before SBT between SBT success group and SBT failure group. The concentration of plasma NT-proBNP in SBT failure group was significantly higher than that of the SBT success group (μg/L: 4.162±1.128 vs. 2.284±1.399, t = 4.905, P = 0.000). The area under ROC curve for plasma NT-proBNP in predicting successful SBT among elder patients with kidney dysfunction was 0.878, with 95% confidence interval (95%CI) 0.786 - 0.970. The cut-off method was used, and it was identified that the concentration of NT-proBNP < 3.350 μg/L as a predictor for successful SBT, with sensitivity of 82.4%, specificity of 87.8%, positive prediction value of 88.1% and negative predictive value of 76.5%. Conclusion The concentration of plasma NT-proBNP may increase in elderly kidney dysfunction patients undergoing ventilation, and NT-proBNP < 3.350 μg/L can serve as a good predictor for SBT success.
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Objective To evaluate the predictive value of N-terminal-pro-brain natriuretic peptide (NT-proBNP) in weaning patients from mechanical ventilation (MV).Methods Data of 42 patients supported with MV in intensive care unit (ICU) admitted to the Rui Jin Hospital from January through December in 2014 were retrospectively analyzed,and the causes for MV were recorded.According to the outcomes of weaning from MV after 48 hours,the patients were divided into two groups namely success group and failure group.Comparisons of fluid balance in 72 hours before spontaneous breathing trial (SBT),and comparisons of NT-proBNP1 levels at admission,NT-proBNP2 levels before SBT,NT-proBNP3 levels after 48 hours after SBT between two groups were carried out.And the receiver operating characteristic (ROC) curve for predicting weaning rate was plotted to find the optimal cut-off point of NT-proBNP2.Results In the total of 42 patients,there were 27 cases in success group and 15 cases in failure group.There were not statistically differences of NT-proBNP1 levels between success group and failure group (P =0.121).However,the NT-proBNP2 levels and NT-proBNP3 levels in failure group were significantly higher than those in success group (P =0.01,0.003).The area under curve (AUC) of the ROC curve of NT-proBNP2 levels to predict the failure of weaning was 0.862 (95％ CI:0.753-0.971).When the optimal cut-off point of NT-proBNP2 was 715.5 pg/mL,the sensitivity and specificity were 93.3％ and 74.1％,respectively.Conclusion The NT-proBNP2 levels before SBT have predictive value in weaning rate,and it can be used as one of the screening indicators for weaning.
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Objective To evaluate the value of NT-proBNP in predicting weaning outcomes of the patients with mechanical ventilation by using the receiver operating characteristic (ROC)curve. Method The data of patients after the weaning of mechanical ventilation and spontaneous breathing trial (SBT) in the intensive care unit,from July 2008 to January 2010, were retrospective reviewed. All patients were divided into the success group and failure group as per the outcomes of weaning. Demographics and the serum NT-proBNP levels measured before weaning were compared between two groups with Student t -test and Chi-square test. The ROC curve was drawn to evaluate the value of serum NT-proBNP in predicting outcomes after weaning. Results A total of 160 patients were eligible for inclusion in the study, and there were 106 cases in success group and 54 cases in failure group.Compared with the failure group, the patients of success group were younger (63.17 ± 17.00 vs. 71.28 ± 12.56,t = 2.063,P =0.024), and no difference in gender (χ2 = 0.06, P ＞ 0.05). The NT-proBNP levels of failure group were significantly higher than those of success group (Lg NT-proBNP 2.80 ± 0.72 vs. 3.75 ± 0.56, t =2.351,P =0.014). The area under cure (AUC) of the ROC cure of NT-proBNPto predict the failure of weaning was 0.855 ±0.036 (95%CI0.784 ～ 0.925) when the cut-off level of NT-proBNP was 3635.5 pg/mL. And, this NT-proBNP level had a followed predictive efficiency in weaning outcome (Youden's index: 0. 60, accuracy:82.5%, sensitivity: 75%, specificity: 84.7%, positive likelihood ratio: 4.90, negative likelihood ratio:0.295,Kappa value: 0.62). Conclusions The levels of NT-proBNP before weaning have predictive value in weaning outcome, and it may be used as one of the screening indicators for weaning.
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BACKGROUND: A number of different weaning techniques can be employed such as spontaneous breathing trial, Intermittent mandatory ventilation(IMV) or Pressure support ventilation(PSV). However, the conclusive data indicating the superiority of one technique over another have not been published. Usually, a conventional spontaneous breathing trial is undertaken by supplying humidified O2 through T-shaped adaptor connected to endotracheal tube or tracheostomy tube. In Korea, T-tube trial is not popular because the high-flow oxygen system is not always available. Also, the timing of extubation is not conclusive and depends on clinical experiences. It is known that to withdraw the endotracheal tube after weaning is far better than to go through any period. The tube produces varying degrees of resistance depending on its internal diameter and the flow rates encountered. The purpose of present study is to evaluate the effectiveness of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotracheal tube. METHODS: We analyzed the result of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotracheal tube in 18 subjects from June, 1993 to June, 1994. They consisted of 9 males and 9 females. The duration of mechanical ventilation was from 38 hours to 341 hours(mean: 105.9 +/- 83.4 hours). In all cases, the cause of ventilator dependency should be identified and precipitating factors should be corrected. The weaning trial was done when the patient became alert and arterial O2 tension was adequate(PaO2 > 55mmHg) with an inspired oxygen fraction of 40%. We conducted a careful physical examination when the patient was breathing spontaneously through the endotracheal tube. Failure of weaning trial was signaled by cyanosis, sweating, paradoxical respiration, intercostal recession. Weaning failure was defined as the need for mechanical ventilation within 48 hours. RESULTS: In 19 weaning trials of 18 patients, successful weaning and extubation was possible in 16/19(84.2% ). During the trial of spontaneous breathing for 60 minutes through the endotracheal tube, the patients who could wean developed slight increase in respiratory rates but significant changes of arterial blood gas values were not noted. But, the patients who failed weaning trial showed the marked increase in respiratory rates without significant changes of arterial blood gas values. CONCLUSION: The result of present study indicates that weaning from mechanical ventilation following a 60 minutes spontaneous breathing with O2 supply through the endotracheal tube is a simple and effective method. Extubation can be done at the same time of successful weaning except for endobronchial toilet or airway protection.