Weaning Outcome Research Articles

Prognostic Value of Rapid Shallow Breathing Index for Weaning Success in Intensive Care Unit Patients under Mechanical Ventilation

Background: The weaning success in intensive care unit patients under mechanical ventilation is very important.
 Objective: The purpose of this study was to investigate the efficacy and effects of rapid shallow breathing index (RSBI) in predicting weaning success in patients with prolonged mechanical ventilation more than 48 hours.
 Methodology: This prospective cohort study was conducted in the Department of Anesthesia, Pain Palliative & Intensive Care Unit of Dhaka Medical College Hospital, Dhaka, Bangladesh from January 2014 to December 2015 for a period of two (02) years. Patients on mechanical ventilation more than 48 hours with the age of 18 to 60 years were included in this study. During the weaning process, the arterial blood gases (ABG) values was checked and the patients was separated from mechanical ventilation. After measuring RSBI, patients was separated from mechanical ventilator and given T-piece trial (1 to 4 hours) and finally extubated as per advice of ICU consultant and observed for 48 hours. The patients were divided in two groups low RSBI ≤105 breath/min/L and high RSBI >105 breath/min/L. These patients were prospectively followed up to 48 hours in ICU and HDU.
 Result: A total of 117 patients were included in this study. The validity of RSBI evaluation for trail failure was correlated by calculating sensitivity, specificity, accuracy, positive and negative predictive values. The sensitivity of RSBI was 54.5% (95% CI 23.38% to 83.25%) and specificity was 82.1% (95% CI 73.43% to 88.85%). However, positive predictive value and negative predictive value were 24.0% (95% CI 13.84% to 38.30%) and 94.6% (95% CI 90.05% to 97.10%) respectively. The accuracy was found 79.5% (95% CI 71.03% to 86.39%). Receiver-operator characteristic (ROC) were constructed using RSBI of the weaning outcome, which gave a RSBI cut off value of ≥88 as the value with a best combination of sensitivity (72.7%) and specificity (61.3%), accuracy (60.7%), positive predictive value (15.7%), negative predictive value (95.5%) for trail failure.
 Conclusion: In conclusion the efficacy and effects of rapid shallow breathing index is found low sensitivity with high specificity in predicting weaning success in patients with prolonged mechanical ventilation more than 48 hours.
 Journal of National Institute of Neurosciences Bangladesh, 2020;6(1): 9-14

The combination of inspiratory muscle training and high-flow nasal cannula oxygen therapy for promoting weaning outcomes in difficult-to-wean patients: protocol for a randomised controlled trial.

BackgroundAccording to the literature, 20–30% of intubated patients are difficult to wean off mechanical ventilation and have a prolonged intensive care unit (ICU) stay with detrimental effects on muscle strength, functional ability and quality of life. Inspiratory muscle training (IMT) via a threshold device has been proposed as an effective exercise for minimising the effects of mechanical ventilation on respiratory muscles of critically ill patients with prolonged weaning. In addition, high-flow nasal cannula (HFNC) oxygen has been proved to provide efficient support for both high- and low-risk patients after extubation, thus preventing re-intubation.Material and methodsA randomised controlled trial was designed to assess the efficacy of combining IMT and HFNC as therapeutic strategies for patients with high risk for weaning failure. Once patients with prognostic factors of difficult weaning are awake, ventilated with support settings and cooperative, they will be randomised to one of the two following study groups: intervention group (IMT and HFNC) and control group (IMT and Venturi mask). IMT will start as soon as possible. Each allocated oxygen delivery device will be applied immediately after extubation. IMT intervention will continue until patients' discharge from ICU. The primary outcome is the rate of weaning failure. Secondary outcomes are maximal inspiratory and expiratory strength, endurance of respiratory muscles, global muscle strength, functional ability and quality of life along with duration of ventilation (days) and ICU and hospital length of stay.ConclusionThe present study could significantly contribute to knowledge of how best to treat patients with difficult weaning and high risk of re-intubation.

Value of Combination of Heart, Lung, and Diaphragm Ultrasound in Predicting Weaning Outcome of Mechanical Ventilation.

BackgroundPostextubation distress is detrimental to the prognosis of critically ill patients with successful spontaneous breathing trial. The known risk factors of failed weaning are associated with the heart, lungs, and diaphragm. The aim of this study was to explore the role of a combined model including indicators of heart, lung, and diaphragm ultrasound in predicting the weaning outcome.Material/MethodsPatients’ clinical data and ultrasonic features of heart, lungs, and diaphragm were recorded. Patients were included in either the failed weaning group (n=24) or the successful weaning group (n=81). The association of potential variables with the risk of weaning failure was determined using multivariate logistic regression analysis. The accuracy of potential indicators for predicting the weaning outcome were evaluated and a multiindicator combined model was established to improve the predictive accuracy.ResultsBrain natriuretic peptide (odds ratio [OR]=1.120, P=0.004), left-atrial pressure (LAP) (OR=1.333, P=0.005), lung ultrasound score (LUS) (OR=1.736, P=0.001), and hemidiaphragm dysfunction (OR=3.942, P=0.014) were associated with an increased risk of weaning failure. However, all of these indicators could not accurately predict the weaning outcome independently (all areas under the curve [AUCs] <0.9). The combination of LAP, LUS, and hemidiaphragm dysfunction showed the highest AUC (AUC=0.919).ConclusionsThe combined model including LAP, LUS, and hemidiaphragm dysfunction were the most accurate method for the prediction.

Efficacy of a standardized tube weaning program in pediatric patients with feeding difficulties after successful repair of their esophageal atresia/tracheoesophageal fistula

Children born with esophageal atresia (EA) might suffer from significant oral feeding problems which could evolve into tube dependency. The primary aim of the study was to define the outcome of tube weaning in children after successful EA repair and to compare outcomes in children with short gap/TEF (tracheoesophageal fistula) and long-gap EA. Data of 64 children (28 with short-gap EA/TEF with primary anastomosis and 36 with long-gap EA with delayed surgical repair) who participated in a standardized tube weaning program based on the “Graz model of tube weaning” (in/outpatients in an intensive 3-week program, online coaching (Netcoaching) only, or a combined 2-week intensive onsite followed by online treatment “Eating School”) from 2009 to 2019 was evaluated. Sixty-one patients completed the program by transitioning to exclusive oral intake (95.3%). Three children (4.7%) were left partially weaned at the time of discharge. No significant differences could be found between short gap/TEF and long-gap EA group regarding outcomes.Conclusions: The study’s findings support the efficacy of tube weaning based on the published “Graz model of tube weaning” for children born with EA/TEF and indicate the necessity of specialized tube weaning programs for these patients.What is Known:• Children with esophageal atresia/tracheoesophageal fistula often suffer from feeding problems and tube dependency.• Different tube weaning programs and outcomes have been published, but not specifically for children with EA.What is New:• Evaluation of a large sample of children referred for tube weaning after EA repair.• Most children with EA can be weaned off their feeding tubes successfully after attending a specialized tube weaning program.

Clinical Application of Ultrasound in Intensive Care Unit-Acquired Weakness.

Intensive care unit-acquired weakness (ICUAW) is common and prolongs the duration of mechanical ventilation and ICU length of stay and is also a leading cause of physical restriction up to five years later. Developing diagnostic tools that allow early identification and risk stratification in all critically ill patients is vital. Ultrasound is a cheap, reproducible and noninvasive imaging modality that can be used to assess multiple muscle groups. It has advantages over other imaging techniques that entail risks of radiation as well as the logistical concerns of moving critically ill patients. Ultrasound muscle indices can be monitored over time and may serve as predictors for ventilatory weaning and long-term outcomes. The diaphragm is frequently perturbed during critical illness, specifically when mechanical ventilation is initiated. Diaphragm thickness and excursion have been shown to support extubation strategy with the former serving as a marker of inspiratory effort in the absence of more specialist tests. The techniques are reproducible with appropriate training and practice and have been applied in clinical trials. Peripheral skeletal muscle ultrasound has been the subject of intense research in ICU-acquired muscle weakness. The technique has also been found to be reproducible and can serve as a surrogate marker to current volitional and non-volitional tests in the assessment of muscle ICUAW. This article outlines the application of musculoskeletal ultrasound and its role in the early recognition of ICUAW in three distinct muscle groups: (1)diaphragm (2) rectus femoris and introduces the potential of (3) parasternal muscles.

Update on Weaning from Veno-Arterial Extracorporeal Membrane Oxygenation.

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) provides temporary cardiac and respiratory support and has emerged as an established salvage intervention for patients with hemodynamic compromise or shock. It is thereby used as a bridge to recovery, bridge to permanent ventricular assist devices, bridge to transplantation, or bridge to decision. However, weaning from VA-ECMO differs between centers, and information about standardized weaning protocols are rare. Given the high mortality of patients undergoing VA-ECMO treatment, it is all the more important to answer the many questions still remaining unresolved in this field Standardized algorithms are recommended to optimize the weaning process and determine whether the VA-ECMO can be safely removed. Successful weaning as a multifactorial process requires sufficient recovery of myocardial and end-organ function. The patient should be considered hemodynamically stable, although left ventricular function often remains impaired during and after weaning. Echocardiographic and invasive hemodynamic monitoring seem to be indispensable when evaluating biventricular recovery and in determining whether the VA-ECMO can be weaned successfully or not, whereas cardiac biomarkers may not be useful in stratifying those who will recover. This review summarizes the strategies of weaning of VA-ECMO and discusses predictors of successful and poor weaning outcome.

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Thoracic fluid content: a novel parameter for predicting failed weaning from mechanical ventilation

BackgroundWeaning of patients from the mechanical ventilation remains one of the critical decisions in intensive care unit. This study aimed to evaluate the accuracy of thoracic fluid content (TFC) as a predictor of weaning outcome.MethodsAn observational cohort study included 64 critically ill surgical patients who were eligible for extubation. Before initiating the spontaneous breathing trial, the TFC was measured using the electrical cardiometry technology. Patients were followed up after extubation and divided into successful weaning group and failed weaning group. Both groups were compared according to respiratory and cardiovascular parameters. Receiver operating characteristic (ROC) curves were constructed to evaluate the ability of TFC to predict weaning outcome.ResultsThe number of successfully weaned patients was 41/64 (64%). Twenty (31%) patients had impaired cardiac contractility, and of them, 13/20 (64%) patients were successfully extubated. Both groups, successful weaning group and failed weaning group, were comparable in most of baseline characteristics; however, the TFC was significantly higher in the failed weaning group compared to the successful weaning group. The area under the ROC curves (AUCs) showed moderate predictive ability for the TFC in predicting weaning failure (AUC [95% confidence interval] 0.69 [0.57–0.8], cutoff value > 50 kΩ−1), while the predictive ability of TFC was excellent in the subgroup of patients with ejection fraction < 40% (AUC [95% confidence interval 0.93 [0.72–1], cutoff value > 50 kΩ−1).ConclusionsThoracic fluid content showed moderate ability for predicting weaning outcome in surgical critically ill patients. However, in the subgroup of patients with ejection fraction less than 40%, TFC above 50 kΩ−1 has an excellent ability to predict weaning failure.

Ventilator induced Diaphragmatic Dysfunction assessed by Ultrasonography and its impact on Weaning outcome

Abstract Background Ventilator induced diaphragmatic dysfunction (VIDD), as a loss of diaphragmatic force generating capacity due to the use of mechanical ventilation. Difficulties in discontinuing ventilatory support are encountered in 20–25% of mechanically ventilated patients, with a staggering 40% of time spent in the intensive care unit being devoted to weaning. M-mode ultrasonography is now an accepted qualitative method of assessing diaphragmatic motion in normal and pathological conditions. In this study, we evaluated whether diaphragmatic excursion (DE) as measured by M-mode sonography can be a predictor of weaning and diagnosis of VIDD. Aim The aim of this study is to determine the presence of ventilator induced diaphragmatic dysfunction (VIDD) diagnosed by M-mode ultrasonography and its impact on weaning outcome. Methodology This study was conducted prospectively in critical care unit in Ain Shams Hospital, a university-affiliated, tertiary referral center in Cairo, Egypt. Study subjects included 78 patients between August 2017 to August 2018. who required mechanical ventilation ≥72hrs. who fulfilled the spontaneous breath trial (SBT) criteria, at the start of a 1-hr SBT, each hemidiaphragm was evaluated M-mode sonography with the patient in the supine position. Rapid shallow Breathing index (RSBI) was simultaneously calculated at the bedside. Ultrasonographic Diaphragmatic Dysfunction (DD) was diagnosed if an Diaphragmatic Excursion (DE) was &amp;lt;10 mm or negative, the latter indicating paradoxical diaphragmatic movement. Results Diaphragmatic Dysfunction (DD) among the eligible 78 patients was 48% (n = 37). DD group had longer weaning time [39,2 (26-56) hrs. vs. 22.3 (30-16) hrs. p = 0.001) in DD vs. NDD group respectively and total ventilation time [140 (130-150) hrs. vs. 130 (120–140) hrs. p &amp;gt; 0.05) in DD vs. NDD group respectively. Weaning failure was (45.8% vs. 30.8%, p=0.01) in DD vs. NDD group respectively. In NDD group Rt. DE, mean 25.4 ±4.1 mm. While Lt. side was 25.3±4.6 mm, 11.25mm and 22mm (45-15) respectively. In DD group Rt. DE, mean 7.6 ±2.02mm, IQR 2.4 mm and median 8.2mm (10-1.9). While Lt. side was 9.2±0.8mm, 4.3mm and 8.9mm (9.8-5.7) respectively. The area under the receiver operating characteristics curve (ROC) of ultrasonographic criteria in predicting weaning failure was near similar to that of rapid shallow breathing index. Hypercapenic acidosis in NDD group might protect them from VIDD Conclusions DD is present in a significant percentage 48% (nearly half) of our medical ICU patients on MV ≥ 72 hrs which largely account for weaning failure. DD was associated with a significant longer weaning time, and ICU stay, with no significant difference in 30 day mortality Recommendations DE by US measurements is a valuable tool and is recommended as an adjunctive weaning index to aid prediction of weaning outcome. Evaluating the role of spontaneous ventilation modes and advanced ventilation modes as PAV and NAVA effects on decreas ing VIDD versus controlled modes.

Variables predicting weaning outcome in prolonged mechanically ventilated tracheotomized patients: a retrospective study

BackgroundSeveral studies have assessed predictors of weaning and extubation outcome in short-term mechanically ventilated patients, but there are only few studies on predictors of weaning from prolonged mechanical ventilation.MethodsRetrospective, single-center, observational study at a specialized national weaning center in Germany. Patients’ medical records were reviewed to obtain data on demographics, comorbidities, respiratory indices, and the result of a prospectively documented, standardized spontaneous breathing trial (SBT) upon admission to the weaning center. Respiratory indices assessed were the ventilatory ratio (VR) and parameters derived from calculated mechanical power (MP). Predictors associated with failure of prolonged weaning and failure of the SBT were assessed using a binary logistic regression model.ResultsA total of 263 prolonged mechanically ventilated, tracheotomized patients, treated over a 5-year period were analyzed. After 3 weeks of mechanical ventilation, patients with unsuccessful weaning failed a SBT more frequently and showed significantly increased values for inspiratory positive airway pressure, driving pressure, VR, absolute MP, and MP normalized to predicted body weight and dynamic lung-thorax compliance (LTC-MP). In the logistic regression analyses, variables independently correlated with weaning failure were female gender (adjusted odds ratio 0.532 [95% CI 0.291–0.973]; p = 0.040), obesity (body mass index ≥ 30 kg/m2) (2.595 [1.210–5.562]; p = 0.014), COPD (3.209 [1.563–6.589]; p = 0.002), LTC-MP (3.470 [1.067–11.284]; p = 0.039), PaCO2 on mechanical ventilation (1.101 [95% CI 1.034–1.173]; p = 0.003), and failure of the SBT (4.702 [2.250–9.825]; p < 0.001). In addition, female gender (0.401 [0.216–0.745]; p = 0.004), LTC-MP (3.017 [1.027–8.862]; p = 0.046), and PaCO2 on mechanical ventilation (1.157 [1.083–1.235]; p < 0.001) were independent risk factors for an unsuccessful SBT.ConclusionsIn the present study, the derived predictors of weaning point to a crucial role of the workload imposed on respiratory muscles during spontaneous breathing. Mechanical power normalized to lung-thorax compliance was independently correlated with weaning outcome and may identify patients at high risk for weaning failure.

Diaphragm and Lung Ultrasound Indices in Prediction of Outcome of Weaning from Mechanical Ventilation in Pediatric Intensive Care Unit.

ObjectiveTo predict the added value of diaphragmatic and lung ultrasound indices (US) in anticipation of the outcome of mechanical ventilation of pediatric patients in the intensive care unit.MethodsThis prospective study was conducted in Zagazig University, Pediatric Hospitals, PICU; Egypt. One hundred six mechanically ventilated children aged between 1 mo to 170 mo were included in the study. All patients were candidates for weaning and have been given a chance for spontaneous breathing trial (SBT), during which diaphragmatic and lung US was performed for them. The diaphragm thickening fraction (DTF), the diaphragmatic excursion and the lung US score (LUS), that included 4 US aeration forms, were assessed.ResultsThere were statistically significant differences between patients with failed weaning and those with successful weaning regarding DTF, diaphragmatic excursion and LUS (p < 0.001). The best cut-off value of DTF, diaphragmatic excursion, and LUS for predicting weaning failure was ≥23.175%, ≥ 6.2 mm, and ≥ 12 with an AUC (area under curve) of 0.932, 0.876, and 0.934, respectively.ConclusionsDiaphragmatic and lung US add a quick, accurate and non-invasive indices to the weaning readiness parameters compared to the other standard parameters alone. So, it is recommended to be added to the predictive parameters of weaning outcome.

Transitional Percentage of Minute Volume as a Novel Predictor of Weaning from Mechanical Ventilation in Patients with Chronic Respiratory Failure

PurposeSome patients with respiratory failure fail initial weaning attempts and need prolonged mechanical ventilation (MV). Prolonged MV is associated with many complications and consumption of heathcare resources. Objective weaning indices help staffs to identify high-potential patients for weaning from the MV. Traditional weaning indices are not reliable in clinical practice. Transitional percentage of minute volume (TMV%) is a new index of the work of breathing. This study aimed to investigate the utility of TMV% in the prediction of weaning potential. MethodsThis study was prospectively performed including all patients with prolonged MV. Researchers recorded their demographics, TMV%, respiratory parameters, Acute Physiology and Chronic Health Evaluation II score, and laboratory data upon arrival at the respiratory care center. The factors associated with successful weaning were analyzed. ResultsOut of the 120 patients included, 84 (70.0%) were successfully weaned from MV. Traditional weaning indices such as rapid shallow breathing index could not predict the weaning outcome. TMV% was a valuable parameter as patients with a lower TMV%, higher tidal volume, higher hemoglobin, lower blood urea nitrogen, and lower Acute Physiology and Chronic Health Evaluation II scores had a higher rate of successful weaning. TMV%, tidal volume, and HCO3- levels were independent predictors of successful weaning, and the area under the curve was .79 in the logistic regression model. ConclusionTMV% is a novel and effective predictor of successful weaning. Patients with lower TMV% had a higher MV weaning outcome. Once patients with a high potential for successful weaning are identified, they should be aggressively weaned from MV as soon as possible. Clinical Trials Government IdentifierNCT033480.

Use of combined cardiac and lung ultrasound to predict weaning failure in elderly, high-risk cardiac patients: a pilot study.

Weaning failure from mechanical ventilation may be due to lung de-recruitment or weaning-induced pulmonary oedema (WIPO). Both can be diagnosed by lung ultrasound (LUS) and transthoracic echocardiography (TTE), respectively. We conducted a prospective observational study, combining TTE and LUS, to determine if LUS alone may identify elderly patients at high risk of weaning or extubation failure. Before and at the end of spontaneous breathing trials (SBT) in 40 elderly patients, we prospectively performed LUS and TTE. Extubation was decided by an independent operator. LUS included global and anterolateral LUS score. TTE included measurement of E/A and E/Ea ratios to determine LV filling pressures. SBT LUS scores for prediction of weaning outcome and for the diagnosis of WIPO were studied. Weaning or extubation failure was observed in 45% (95% CI 28-61) of patients. ROC analysis for ability of global SBT LUS to predict weaning/extubation failure and extubation failure found AUC of 0.80 and 0.81, respectively. AUC for anterolateral SBT LUS to predict weaning/extubation failure and extubation failure was 0.79 and 0.81, respectively. Increased LV filling pressure during SBT was observed without increase of anterolateral LUS score. Inversely, increase of anterolateral LUS was observed without increased filling pressure and was associated with extubation failure. Global and anterolateral SBT LUS were not correlated to E/Ea. In elderly patients, global and anterolateral LUS scores were associated with weaning and extubation failures while echocardiographic indices of filling pressures were not. ClinicalTrials.gov No. NCT03261440.

Airway pressure release ventilation in comparison to synchronized intermittent mandatory ventilation in acute respiratory failure: a randomized controlled trial

Background The main goal of mechanical ventilation is to support the respiratory drive safely and optimally. The authors are always transitioning through modes of mechanical ventilation either traditional or novel modes, trying to find out the optimum for each ventilation purpose. Recently, airway pressure release ventilation (APRV) has been digging through causes of respiratory failure, as a promising and challenging mode with interesting achievements throughout the clinical trials and case reports. Specially in critically ill patients with severe respiratory failure by means of offering a protective lung strategy throughout, recruiting it safely with better outcomes. Thoroughly, the authors aimed from this study to explore the hidden potentials of APRV mode as a safe recruiting mode could improve the gas exchange by increasing the surface area and maintain the opened alveoli for a while to get rid of inflammatory edema in comparison to the default ventilation mode in any type of respiratory failure. Patients and methods Single-blinded, randomized, controlled trial, which included 152 pediatric patients (56 men and 96 women) in an age range of 8 months to 17 years, who were admitted to the intensive care units either in Pediatrics, Chest Diseases, Anesthesia, or Internal Medicine Departments, Zagazig University Hospitals, Egypt, with acute respiratory failure. Of the patients, 76 were assigned to APRV mode and the other 76 patients were assigned to synchronized intermittent mandatory ventilation mode during a period from April 2017 to Jun 2019. Follow-up of arterial blood gases, ventilatory parameters, and vital signs were recorded. Primary and secondary outcomes including duration of ventilation, weaning outcome, and rate of mortality were documented. Results No significant difference was found between the APRV group and the synchronized intermittent mandatory ventilation group regarding mortality, complications, and weaning outcome. However, there was significant difference between outcomes of the challenging cases labeled acute respiratory distress syndrome and pulmonary edema connected to APRV. Conclusion The APRV mode showed superiority in supporting acute respiratory distress syndrome and pulmonary edema patients, with no higher risk of mortality or complications.

Are diaphragmatic indices assessed by ultrasound good predictors of weaning outcome in mechanically ventilated respiratory patients?

Background Prediction of weaning outcome is still challenging. Among the reported causes of weaning failure is the diaphragmatic dysfunction. Diaphragmatic ultrasound indices were endorsed for predicting weaning outcome but with conflicting results. Therefore, this study aimed to evaluate ultrasonographic diaphragmatic indices for predicting weaning outcome in respiratory intensive care unit (RICU) patients. Patients and methods The study enrolled 40 RICU patients who were considered eligible for spontaneous breathing trial (SBT). Ultrasound of the right hemidiaphragm was performed immediately after the start of SBT. Assessment of the diaphragmatic excursion using M-mode in semisitting position was done. Moreover, the diaphragmatic thickness at the end of inspiration (Tdi) and expiration (Tdex), with the patient in supine position, was assessed. Diaphragmatic thickness fraction was then calculated. During SBT, patients’ respiratory rate, heart rate, rapid shallow breathing index (RSBI), and minute ventilation were recorded. Tracheal airway occlusion pressure (P0.1) and negative inspiratory force were measured using the ventilator software. Results The diaphragmatic indices did not appear to have a significant role in predicting successful weaning with area under the curve less than 0.56 for all of them. Moreover, no statistically significant difference in Tdi, Tdexe, thickness fraction, and diaphragmatic excursion was observed between the success and failure weaning groups. However, the RSBI performed as the best parameter in predicting weaning success, with area under the curve of 0.831. A cutoff value of 78 had 91% sensitivity and 84% specificity. Conclusion Ultrasonographic diaphragmatic indices are not satisfactory tools to predict weaning outcome in RICU compared with RSBI and other reported traditional indices.

Predictive value of diaphragmatic rapid shallow breathing index in mechanical ventilation weaning: a systematic review and meta-analysis

Background: Mechanical ventilation weaning is a multifactorial process. D-RSBI cannot only reflect the respiratory function but also the diaphragmatic function with the bedside ultrasound technique. Objective: This review aimed to assess the predictive value of diaphragmatic rapid shallow breathing index (D-RSBI) of weaning outcome. Method: Databases were systematically reviewed including PubMed, Cochrane Library, Embase, CNKI and WanFang Data. Sensitivity and specificity were pooled with random effects models. Results: Nine studies met the inclusion criteria and 568 patients were involved. D-RSBI had a pooled sensitivity of 0.84 and a pooled specificity of 0.87 which predicted weaning success. D-RSBI in the success group was significantly lower than the weaning failure group. Conclusion: D-RSBI is a sensitive and specific predictor for weaning outcomes in spite of the limitations and heterogeneity among the studies. Further studies focusing on particular disease are needed as well.

Predictive value of lung ultrasound score on weaning outcome in patients with intro-abdominal infection undergoing mechanical ventilation

To evaluate the value of lung ultrasound score (LUS) on predicting weaning outcome in patients with intro-abdominal infection (IAI) undergoing mechanical ventilation. Patients with IAI undergoing mechanical ventilation admitted to Research Institute of General Surgery of East War Zone Hospital and intensive care unit (ICU) of the First People's Hospital of Lianyungang from January to December in 2018 were included. The patients who satisfied weaning criteria were enrolled in the weaning process, which included spontaneous breathing trial (SBT) and extubation. They were divided into SBT success group and SBT failure group according to whether passed 120-minute SBT or not. LUS scores before and after SBT were compared between the two groups. The patients in the SBT success group were extubated, and they were divided into successful extubation group and failed extubation group for sub-group analysis according to whether re-intubation was needed in 48 hours after extubation. LUS score before extubation (at the end of SBT) and 48 hours after extubation (48 hours after extubation in the successful extubation group or before re-intubation in the failed extubation group) were compared. The receiver operating characteristic (ROC) curve was drawn to evaluate the predictive value of LUS score before SBT for SBT failure and LUS score before extubation for the failure. A total of 76 patients with IAI undergoing mechanical ventilation were included. Twenty-three patients had duration of mechanical ventilation less than 48 hours, severe chronic obstructive pulmonary disease (COPD), tracheotomy or automatic discharge were excluded, and 53 patients were enrolled. SBT was failed in 9 patients, and successfully performed in 44 patients, of whom 23 patients with successful extubation, and 21 with failed extubation. The LUS scores before and after SBT in the SBT failure group were significantly higher than those in the SBT success group (before SBT: 13.22±1.99 vs. 10.79±1.64, t = -3.911, P = 0.000; after SBT: 19.00±1.12 vs. 13.41±1.86, t = -8.665, P = 0.000). ROC curve analysis showed that the area under ROC curve (AUC) of LUS score before SBT for predicting SBT failure was 0.82 [95% confidence interval (95%CI) was 0.67-0.98, P = 0.002]. When the optimum cut-off value was 12.5, the sensitivity was 66.7%, and the specificity was 84.1%. Sub-group analysis showed that the LUS scores before and after extubation in the failed extubation group were significantly higher than those in the successful extubation group (before extubation: 14.19±1.60 vs. 12.69±1.81, t = -2.881, P = 0.006; after extubation: 16.42±1.59 vs. 12.78±1.54, t = -7.710, P = 0.000). ROC curve analysis showed that the AUC of LUS score before extubation for predicting the failure was 0.81 (95%CI was 0.69-0.92, P = 0.000). When the optimum cut-off value was 13.5, the sensitivity was 80.0%, and the specificity was 65.2%. LUS score can effectively predict SBT outcome, risk of re-intubation after extubation in patients with IAI undergoing mechanical ventilation.

A study of different predictors of successful weaning off mechanical ventilation in ventilated patients with chronic obstructive pulmonary disease with acute respiratory failure

Background A lot of indices can be used as predictors of weaning off mechanical ventilation, such as rapid shallow breathing index (RSBI), integrative weaning index (IWI), vital capacity (VC), maximal inspiratory pressure (MIP), and respiratory rate (RR). MIP and IWI were considered the most sensitive parameters for prediction of weaning. Objective To compare between the efficacies of some predictors of successful weaning in ventilated patients with chronic obstructive pulmonary disease with acute respiratory failure. Design A total of 30 patients with chronic obstructive pulmonary disease with acute respiratory failure were mechanically ventilated and classified into two groups, with 15 patients each. Clinical and demographic data assessment and routine investigations were done for all patients, and then RSBI and IWI were measured in group I, and also VC and MIP were measured in group II, whereas RR was measured in the two groups. Results Successful cases had significantly short duration of ventilation and high IWI, MIP, and VC, but RSBI was significantly lower in successful cases, whereas RR was significantly high in failed cases. Conclusion MIP and IWI were considered the most sensitive parameters in predicting the outcome of weaning, and prolonged duration on mechanical ventilation was associated with weaning failure.

Application of lung ultrasound for predicting outcome of weaning from mechanical ventilation

Background Weaning failure is an important issue among critically ill patients. Currently, lung ultrasound (US) is a useful tool to early predict this problem. This study was conducted to assess the efficacy of lung ultrasound to predict early weaning failure in critically ill patients. Patients and methods A total of 50 patients requiring mechanical ventilation (MV) were included in this prospective observational study. Patients were divided into two groups after 48 h: group NS included patients who were unsuccessfully weaned, either failed 30 min of spontaneous breathing trial (SBT) or reintubated within 24 h after being extubated, and group S included patients who were successfully weaned (extubated). Lung US was completed for all patients, 1 h before SBT while patients were mechanically ventilated, 30 min after SBT, and 6 h after extubation. Patients were prospectively followed up for the need for reintubation and mechanical ventilation or the need for non-invasive positive pressure ventilation (NIPPV) after successful extubation (primary endpoints). The length of Intensive care Unit (ICU) stay, duration of mechanical ventilation (MV) and ICU mortality (secondary end points). Results Lung US done for all patients in the anterior, lateral, and posterior regions of the lung showed significantly high lung US score in group NS than group S (P Conclusions Lung US can accurately detect lung aeration changes and predict weaning outcome through estimating the lung US scoring system for lung aeration changes where high scores are associated with weaning failure.

Lung ultrasound score before and after extubation for predicting weaning outcome

Background: Lung ultrasound (LUS) is an emerging, essential, safe and easily repeatable bed­side tool being used for the management of critically ill patients in ICUs. Weaning off the ventilator and decide to extubate require right decision and appropriate timing to avoid ex­tubation failure. The study aimed to perform LUS in planned extubation patients who passed SBT, for the assessment of lungs, before and after extubation.&#x0D; Methods: A single-centre, observational study at medical ICU of a tertiary level hospital in Nepal was conducted on invasive mechanically ventilated patients. LUS was performed be­fore extubation on those who were planned to extubate and repeat scan done after 24 hours of extubation. LUS scores were calculated at both times. p-value 0.05 was considered statisti­cally significant.&#x0D; Results: Twenty-eight patients were included after passing spontaneous breathing trial (SBT), one patient had extubation failure. Mean LUS score before and after extubation came to be 16.15 ± 7.00 and 13.15 ± 4.59 respectively with high degree of correlation (Pearson’s r = 0.896, P &lt;0.001). The mean difference in LUS scores before and after extubation was signifi­cant (Mean difference: 3.00 ± 3.54, t = 4.402, p &lt; 0.001).&#x0D; Conclusions: Lung ultrasound is very useful additive tool in predicting extubation failure eas­ily and timely. Its use after extubation also helps in early prediction of post-extubation failure by assessing aeration changes and other lung pathology.