Mechanical power density, spontaneous breathing indexes, and prolonged weaning failure: a prospective cohort study.

A prospective observational study comparing mechanical power density (MP normalized to dynamic compliance) with traditional spontaneous breathing indexes (e.g., predicted body weight normalized tidal volume [VT/PBW], rapid shallow breathing index [RSBI], or the integrative weaning index [IWI]) for predicting prolonged weaning failure in 140 tracheotomized patients. We assessed the diagnostic accuracy of these indexes at the start and end of the weaning procedure using ROC curve analysis, expressed as the area under the receiver operating characteristic curve (AUROC). Weaning failure occurred in 41 out of 140 patients (29%), demonstrating significantly higher MP density (6156 cmH2O2/min [4402-7910] vs. 3004 cmH2O2/min [2153-3917], P < 0.01), lower spontaneous VT/PBW (5.8 mL*kg-1 [4.8-6.8] vs. 6.6 mL*kg-1 [5.7-7.9], P < 0.01) higher RSBI (68 min-1*L-1 [44-91] vs. 55 min-1*L-1 [41-76], P < 0.01) and lower IWI (41 L2/cmH2O*%*min*10-3 [25-72] vs. 71 L2/cmH2O*%*min*10-3 [50-106], P < 0.01) and at the end of weaning. MP density was more accurate at predicting weaning failures (AUROC 0.91 [95%CI 0.84-0.95]) than VT/PBW (0.67 [0.58-0.74]), RSBI (0.62 [0.53-0.70]), or IWI (0.73 [0.65-0.80]), and may help clinicians in identifying patients at high risk for long-term ventilator dependency.

Diaphragm ultrasound in patients with prolonged weaning from mechanical ventilation.

Background: Several publications have examined diaphragmatic ultrasound using two-dimensional (2D) parameters in the context of weaning from mechanical ventilation (MV) and extubation. However, the studied cohorts had rather short duration of ventilation. Examinations on patients with prolonged weaning after long-term ventilation were missing. It was the aim of this study to assess of the diaphragm and peripheral musculature of patients undergoing prolonged weaning creating a chronological sequence of ultrasonic parameters during the course of weaning. Methods: This study was carried out as a monocentric, prospective observational cross-sectional study. Patients in prolonged weaning who were transferred to a specialized weaning unit were eligible for inclusion if they were ventilated invasively by means of an endotracheal tube or tracheal cannula and if their expected treatment period was at least 5 days. Diaphragmatic function and one representative peripheral muscle were examined in 50 patients between March 2020 and April 2021. The 2D sonographic parameters of diaphragm and diaphragmatic function consisted of diaphragmatic thickness (Tdi) at the end of inspiration and expiration, the fractional thickening (FT) and the diaphragmatic excursion. Additionally, the M. quadriceps femoris was sonographically assessed at two locations. The difference of measurements between the first and the last measuring timepoint were examined using the Wilcoxon signed-rank test. For a longer chronological sequence, the Friedman's rank sum test with subsequent Wilcoxon-Nemenyi-McDonald-Thompson test for multiple comparisons was carried out. Results: Fifty patients with prolonged weaning were included. The median duration of MV before transfer to the weaning unit was 11.5 [interquartile range (IQR) 10] days. Forty-one patients could be assessed over the full course of weaning, with 38 successfully weaned. Within these 41 patients, the sonographic parameters of the diaphragm slightly increased over the course of weaning indicating an increase in thickness and mobility. Especially parameters which represented an active movement reached statistical significance, i.e., inspiratory Tdi when assessed under spontaneous breathing [begin 3.41 (0.99) vs. end 3.43 (1.31) mm; P=0.01] and diaphragmatic excursion [begin 0.7 (0.8) vs. end 0.9 (0.6) cm; P=0.01]. The presence of positive end-expiratory pressure (PEEP) and pressure support did not influence the sonographic parameters significantly. The M. quadriceps femoris, in contrast, decreased slightly but constantly over the time [lower third: begin 1.36 (0.48) vs. end 1.28 (0.36) cm; P=0.054]. Conclusions: The present study is the first one to longitudinally analyse diaphragmatic ultrasound in patients with prolonged weaning. Sonographic assessment showed that Tdi and excursion increased over the course of prolonged weaning, while the diameter of a representative peripheral muscle decreased. However, the changes are rather small, and data show a wide dispersion. To allow a potential, standardized use of diaphragm ultrasound for diagnostic decision support in prolonged weaning, further studies in this specific patient group are required.

Development of a machine learning model for prediction of the duration of unassisted spontaneous breathing in patients during prolonged weaning from mechanical ventilation.

PURPOSE: Treatment of patients undergoing prolonged weaning from mechanical ventilation includes repeated spontaneous breathing trials (SBTs) without respiratory support, whose duration must be balanced critically to prevent over- and underload of respiratory musculature. This study aimed to develop a machine learning model to predict the duration of unassisted spontaneous breathing. MATERIALS AND METHODS: Structured clinical data of patients from a specialized weaning unit were used to develop (1) a classifier model to qualitatively predict an increase of duration, (2) a regressor model to quantitatively predict the precise duration of SBTs on the next day, and (3) the duration difference between the current and following day. 61 features, known to influence weaning, were included into a Histogram-based gradient boosting model. The models were trained and evaluated using separated data sets. RESULTS: 18.948 patient-days from 1018 individual patients were included. The classifier model yielded an ROC-AUC of 0.713. The regressor models displayed a mean absolute error of 2:50 h for prediction of absolute durations and 2:47 h for day-to-day difference. CONCLUSIONS: The developed machine learning model showed informed results when predicting the spontaneous breathing capacity of a patient in prolonged weaning, however lacking prognostic quality required for direct translation to clinical use.

Role of multidrug-resistant bacteria in weaning from invasive mechanical ventilation.

BACKGROUND: Although multidrug-resistant bacteria (MDR) are common in patients undergoing prolonged weaning, there is little data on their impact on weaning and patient outcomes. METHODS: This is a retrospective analysis of consecutive patients who underwent prolonged weaning and were at a university weaning centre from January 2018 to December 2020. The influence of MDR colonisation and infection on weaning success (category 3a and 3b), successful prolonged weaning from invasive mechanical ventilation (IMV) with or without the need for non-invasive ventilation (NIV) compared with category 3c (weaning failure 3cI or death 3cII) was investigated. The pathogen groups considered were: multidrug-resistant gram-negative bacteria (MDRGN), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus spp. (VRE). RESULTS: A total of 206 patients were studied, of whom 91 (44.2%) showed evidence of MDR bacteria (32% VRE, 1.5% MRSA and 16% MDRGN), with 25 patients also meeting the criteria for MDR infection. 70.9% of the 206 patients were successfully weaned from IMV, 8.7% died. In 72.2% of cases, nosocomial pneumonia and other infections were the main cause of death. Patients with evidence of MDR (infection and colonisation) had a higher incidence of weaning failure than those without evidence of MDR (48% vs. 34.8% vs. 21.7%). In multivariate analyses, MDR infection (OR 4.9, p = 0.004) was an independent risk factor for weaning failure, along with male sex (OR 2.3, p = 0.025), Charlson Comorbidity Index (OR 1.2, p = 0.027), pH (OR 2.7, p < 0.001) and duration of IMV before admission (OR 1.01, p < 0.001). In addition, MDR infection was the only independent risk factor for death (category 3cII), (OR 6.66, p = 0.007). CONCLUSION: Patients with MDR infection are significantly more likely to die during the weaning process. There is an urgent need to develop non-antibiotic approaches for the prevention and treatment of MDR infections as well as clinical research on antibiotic stewardship in prolonged weaning as well as in ICUs.

Risk factors for long-term invasive mechanical ventilation: a longitudinal study using German health claims data.

BACKGROUND: Long-term invasive mechanical ventilation (IMV) is a major burden for those affected and causes high costs for the health care system. Early risk assessment is a prerequisite for the best possible support of high-risk patients during the weaning process. We aimed to identify risk factors for long-term IMV within 96 h (h) after the onset of IMV. METHODS: The analysis was based on data from one of Germany's largest statutory health insurance funds; patients who received IMV ≥ 96 h and were admitted in January 2015 at the earliest and discharged in December 2017 at the latest were analysed. OPS and ICD codes of IMV patients were considered, including the 365 days before intubation and 30 days after discharge. Long-term IMV was defined as evidence of invasive home mechanical ventilation (HMV), IMV ≥ 500 h, or readmission with (re)prolonged ventilation. RESULTS: In the analysis of 7758 hospitalisations, criteria for long-term IMV were met in 38.3% of cases, of which 13.9% had evidence of HMV, 73.1% received IMV ≥ 500 h and/or 40.3% were re-hospitalised with IMV. Several independent risk factors were identified (p < 0.005 each), including pre-diagnoses such as pneumothorax (OR 2.10), acute pancreatitis (OR 2.64), eating disorders (OR 1.99) or rheumatic mitral valve disease (OR 1.89). Among ICU admissions, previous dependence on an aspirator or respirator (OR 5.13), and previous tracheostomy (OR 2.17) were particularly important, while neurosurgery (OR 2.61), early tracheostomy (OR 3.97) and treatment for severe respiratory failure such as positioning treatment (OR 2.31) and extracorporeal lung support (OR 1.80) were relevant procedures in the first 96 h after intubation. CONCLUSION: This comprehensive analysis of health claims has identified several risk factors for the risk of long-term ventilation. In addition to the known clinical risks, the information obtained may help to identify patients at risk at an early stage. Trial registration The PRiVENT study was retrospectively registered at ClinicalTrials.gov (NCT05260853). Registered at March 2, 2022.

Effects of structured protocolized physical therapy on the duration of mechanical ventilation in patients with prolonged weaning.

PURPOSE: 20% of patients with mechanical ventilation (MV) have a prolonged, complex weaning process, often experiencing a condition of ICU-acquired weakness (ICUAW), with a severe decrease in muscle function and restricted long-term prognosis. We aimed to analyze a protocolized, systematic approach of physiotherapy in prolonged weaning patients and hypothesized that the duration of weaning from MV would be shortened. METHODS: ICU patients with prolonged weaning were included before (group 1) and after (group 2) introduction of a quality control measure of a structured and protocolized physiotherapy program. Primary endpoint was the tested dynamometric handgrip strength and the Surgical Intensive Care Unit Optimal Mobilization Score (SOMS). Secondary endpoints were weaning success rate, ventilator-free days, hospital mortality, the prevalence of ICUAW, infections and delirium. RESULTS: 106 patients were included. Both the SOMS and the handgrip test were significantly improved after introducing the program. Despite no differences in weaning success rates at discharge, the total length of MV was significantly shorter in group 2, which also had lower prevalence of infection and higher probability of survival. CONCLUSIONS: Protocolized, systematic physiotherapy resulted in an improvement of the clinical outcome in patients with prolonged weaning. Results were objectifiable with the SOMS and the handgrip test.

Costs of Weaning Failure: A Prospective, Multicentre, Controlled, Non-Randomised, Interventional Study on Economic Implications for the German Health Care System.

BACKGROUND: Intensive care patients with respiratory failure often need invasive mechanical ventilation (IMV). With increasing population age and multimorbidity, the number of patients who cannot be weaned from IMV rises as well. Up to 85% of these patients have no access to a certified weaning centre. Their medical care is associated with impaired quality of life and high costs for the German health care system. OBJECTIVES: This study examined the weaning outcome of patients in certified weaning centres after a primarily unsuccessful weaning attempt in order to calculate saving expenses compared to patients on long-term IMV in an outpatient setting. METHODS: In this multicentre, controlled, non-randomised, interventional, prospective study, 61 patients (16 from out-of-hospital long-term IMV, 49 from other hospitals) were referred to a certified weaning centre for a second weaning phase. The incurred costs after 1 year of the latter were compared to insurance claim data of patients who were discharged from an acute hospital stay to receive IMV in an outpatient setting. RESULTS: In the intervention group, 50 patients (82%) could be completely weaned or partially weaned using non-invasive ventilation, thus not needing IMV any longer. The costs per patient for weaning and out-of-hospital care in the intervention group were EUR 114,877.08, and the costs in the comparison cohort were EUR 234,442.62. CONCLUSIONS: Early transfer to a certified weaning centre can increase weaning success and reduce total costs by approximately EUR 120,000 per patient in the first year. Given the existing structural prerequisites in Germany, every patient should have access to a weaning centre before being transferred to long-term IMV, from a medical and health economical point of view.

Ventilatory ratio and mechanical power in prolonged mechanically ventilated COVID-19 patients versus respiratory failures of other etiologies.

BACKGROUND: Evidence suggests differences in ventilation efficiency and respiratory mechanics between early COVID-19 pneumonia and classical acute respiratory distress syndrome (ARDS), as measured by established ventilatory indexes, such as the ventilatory ratio (VR; a surrogate of the pulmonary dead-space fraction) or mechanical power (MP; affected, e.g., by changes in lung-thorax compliance). OBJECTIVES: The aim of this study was to evaluate VR and MP in the late stages of the disease when patients are ready to be liberated from the ventilator after recovering from COVID-19 pneumonia compared to respiratory failures of other etiologies. DESIGN: A retrospective observational cohort study of 249 prolonged mechanically ventilated, tracheotomized patients with and without COVID-19-related respiratory failure. METHODS: We analyzed each group's VR and MP distributions and trajectories [repeated-measures analysis of variance (ANOVA)] during weaning. Secondary outcomes included weaning failure rates between groups and the ability of VR and MP to predict weaning outcomes (using logistic regression models). RESULTS: The analysis compared 53 COVID-19 cases with a heterogeneous group of 196 non-COVID-19 subjects. VR and MP decreased across both groups during weaning. COVID-19 patients demonstrated higher values for both indexes throughout weaning: median VR 1.54 versus 1.27 (p < 0.01) and MP 26.0 versus 21.3 Joule/min (p < 0.01) at the start of weaning, and median VR 1.38 versus 1.24 (p < 0.01) and MP 24.2 versus 20.1 Joule/min (p < 0.01) at weaning completion. According to the multivariable analysis, VR was not independently associated with weaning outcomes, and the ability of MP to predict weaning failure or success varied with lung-thorax compliance, with COVID-19 patients demonstrating consistently higher dynamic compliance along with significantly fewer weaning failures (9% versus 30%, p < 0.01). CONCLUSION: COVID-19 patients differed considerably in ventilation efficiency and respiratory mechanics among prolonged ventilated individuals, demonstrating significantly higher VRs and MP. The differences in MP were linked with higher lung-thorax compliance in COVID-19 patients, possibly contributing to the lower rate of weaning failures observed.

Early prediction of hospital outcomes in patients tracheostomized for complex mechanical ventilation weaning.

BACKGROUND: Tracheostomy is often performed in the intensive care unit (ICU) when mechanical ventilation (MV) weaning is prolonged to facilitate daily care. Tracheostomized patients require important healthcare resources and have poor long-term prognosis after the ICU. However, data lacks regarding prediction of outcomes at hospital discharge. We looked for patients' characteristics, ventilation parameters, sedation and analgesia use (pre-tracheostomy) that are associated with favorable and poor outcomes (post-tracheostomy) using univariate and multivariate logistic regressions. RESULTS: Eighty tracheostomized patients were included (28.8% women, 60 [52-71] years). Twenty-three (28.8%) patients were intubated for neurological reasons. Time from intubation to tracheostomy was 14.7 [10-20] days. Thirty patients (37.5%) had poor outcome (19 patients deceased and 11 still tracheostomized at hospital discharge). All patients discharged with tracheostomy (n = 11) were initially intubated for a neurological reason. In univariate logistic regressions, older age and higher body-mass index (BMI) were associated with poor outcome (OR 1.18 [1.07-1.32] and 1.04 [1.01-1.08], p < 0.001 and p = 0.025). No MV parameters were associated with poor outcome. In the multiple logistic regression model higher BMI and older age were also associated with poor outcome (OR 1.21 [1.09-1.36] and 1.04 [1.00-1.09], p < 0.001 and p = 0.046). CONCLUSIONS: Hospital mortality of patients tracheostomized because of complex MV weaning was high. Patients intubated for neurological reasons were frequently discharged from the acute care hospital with tracheostomy in place. Both in univariate and multivariate logistic regressions, only BMI and older age were associated with poor outcome after tracheostomy for patients undergoing prolonged MV weaning.

Prolonged Weaning: S2k Guideline Published by the German Respiratory Society.

Mechanical ventilation (MV) is an essential part of modern intensive care medicine. MV is performed in patients with severe respiratory failure caused by respiratory muscle insufficiency and/or lung parenchymal disease; that is, when other treatments such as medication, oxygen administration, secretion management, continuous positive airway pressure (CPAP), or nasal high-flow therapy have failed. MV is required for maintaining gas exchange and allows more time to curatively treat the underlying cause of respiratory failure. In the majority of ventilated patients, liberation or "weaning" from MV is routine, without the occurrence of any major problems. However, approximately 20% of patients require ongoing MV, despite amelioration of the conditions that precipitated the need for it in the first place. Approximately 40-50% of the time spent on MV is required to liberate the patient from the ventilator, a process called "weaning". In addition to acute respiratory failure, numerous factors can influence the duration and success rate of the weaning process; these include age, comorbidities, and conditions and complications acquired during the ICU stay. According to international consensus, "prolonged weaning" is defined as the weaning process in patients who have failed at least 3 weaning attempts, or require more than 7 days of weaning after the first spontaneous breathing trial (SBT). Given that prolonged weaning is a complex process, an interdisciplinary approach is essential for it to be successful. In specialised weaning centres, approximately 50% of patients with initial weaning failure can be liberated from MV after prolonged weaning. However, the heterogeneity of patients undergoing prolonged weaning precludes the direct comparison of individual centres. Patients with persistent weaning failure either die during the weaning process, or are discharged back to their home or to a long-term care facility with ongoing MV. Urged by the growing importance of prolonged weaning, this Sk2 Guideline was first published in 2014 as an initiative of the German Respiratory Society (DGP), in conjunction with other scientific societies involved in prolonged weaning. The emergence of new research, clinical study findings and registry data, as well as the accumulation of experience in daily practice, have made the revision of this guideline necessary. The following topics are dealt with in the present guideline: Definitions, epidemiology, weaning categories, underlying pathophysiology, prevention of prolonged weaning, treatment strategies in prolonged weaning, the weaning unit, discharge from hospital on MV, and recommendations for end-of-life decisions. Special emphasis was placed on the following themes: (1) A new classification of patient sub-groups in prolonged weaning. (2) Important aspects of pulmonary rehabilitation and neurorehabilitation in prolonged weaning. (3) Infrastructure and process organisation in the care of patients in prolonged weaning based on a continuous treatment concept. (4) Changes in therapeutic goals and communication with relatives. Aspects of paediatric weaning are addressed separately within individual chapters. The main aim of the revised guideline was to summarize both current evidence and expert-based knowledge on the topic of "prolonged weaning", and to use this information as a foundation for formulating recommendations related to "prolonged weaning", not only in acute medicine but also in the field of chronic intensive care medicine. The following professionals served as important addressees for this guideline: intensivists, pulmonary medicine specialists, anaesthesiologists, internists, cardiologists, surgeons, neurologists, paediatricians, geriatricians, palliative care clinicians, rehabilitation physicians, intensive/chronic care nurses, physiotherapists, respiratory therapists, speech therapists, medical service of health insurance, and associated ventilator manufacturers.

Arnold-Chiari malformation type I and the posterior dislocation of the odontoid process aggravate prolonged weaning in a patient with severe viral pneumonia: a case report.

BACKGROUND: Prolonged and difficult weaning is associated with higher rates of complications and mortality. Therefore, it is important to identify the associated factors. CASE PRESENTATION: We describe our experience with a 37-year-old man diagnosed with severe viral pneumonia (influenza A). He presented with acute respiratory failure type I on admission. During intubation, his blood pressure and heart rate decreased, and epinephrine and norepinephrine were administered. Although his clinical condition improved 8 days after intensive care unit (ICU) admission, he experienced difficulty weaning. He remained conscious but had a poor spontaneous cough with sputum production and weak limb muscle strength. His cough reflex was absent during bronchoscopic sputum suction, and he used abdominal breathing during the T-tube test. Magnetic resonance imaging revealed an Arnold-Chiari malformation type I, posterior dislocation of the odontoid process, and syringomyelia, with compression and deformation of the medulla and high cervical cord. The patient was successfully weaned from the ventilator at 20 days after ICU admission. CONCLUSIONS: Arnold-Chiari malformation type I and posterior dislocation of the odontoid process, which aggravate medullary compression and increase the risk of cervical nerve injury, might be a rare factor affecting prolonged weaning in critical illness.

The spontaneous breathing trial is of low predictive value regarding spontaneous breathing ability in subjects with prolonged, unsuccessful weaning.

BACKGROUND: The spontaneous breathing trial (SBT) is a well-established diagnostic test for predicting extubation failure in intubated intensive care unit (ICU) patients. However, the SBT has not been evaluated in a specific cohort of tracheostomized patients in whom weaning is prolonged and ultimately unsuccessful. OBJECTIVE: The aim of the trial was to investigate the relevance of SBT failure criteria in chronic respiratory failure subjects undergoing long-term invasive home mechanical ventilation following tracheostomy and weaning failure. METHODS: Measurement of all established failure criteria including pneumotachygraphical assessment of the rapid shallow breathing index (RSBI) took place during an SBT. The decision to continue spontaneous breathing was based on failure criteria as well as the subjective willingness of the patient. RESULTS: Fifteen subjects with a median age of 58 years (interquartile range [IQR] 44-74) were studied; 10 with COPD, 4 with neuromuscular diseases and 1 with both. Twelve subjects met the SBT failure criteria within 30 min, but one third of these subjects were still able to continue with spontaneous breathing. In contrast, 3 subjects could not be weaned despite the SBT being successful. An increased RSBI was the most frequently observed SBT failure criterion (57% of all SBT). However, the SBT varied substantially in individual subjects who were able to sustain spontaneous breathing, despite having reached the cut-off for SBT failure. CONCLUSION: The SBT was of low predictive value regarding spontaneous breathing ability in chronic respiratory failure subjects with prolonged, unsuccessful weaning.

Noninvasive ventilation during weaning from prolonged mechanical ventilation.

BACKGROUND AND OBJECTIVE: Non invasive ventilation (NIV) is currently employed for weaning from invasive ventilation (IMV) in the acute setting but its use for weaning from prolonged ventilation is still occasional and not standardized. We wanted to evaluate whether a combined protocol of NIV and decannulation in tracheostomized patients needing prolonged mechanical ventilation was feasible and what would be the one-year outcome. METHODS: We studied patients still dependent from invasive mechanical ventilation with the following inclusion criteria: a) tolerance of at least 8h of unsupported breathing, b) progressive hypercapnia/acidosis after invasive ventilation discontinuation, c) good adaptation to NIV, d) favorable criteria for decannulation. These patients were switched from IMV to NIV and decannulated; then they were discharged on home NIV and followed-up for one year in order to evaluate survival and complications rate. RESULTS: Data from patients consecutively admitted to a weaning unit were prospectively collected between 2005 and 2018. Out of 587 patients admitted over that period, 341 were liberated from prolonged mechanical ventilation. Fifty-one out of 147 unweaned patients (35%) were eligible for the protocol but only 46 were enrolled. After a mean length of stay of 35 days they were decannulated and discharged on domiciliary NIV. After one year, 38 patients were still alive (survival rate 82%) and 37 were using NIV with good adherence (only one patient was switched again to invasive ventilation). CONCLUSIONS: NIV applied to patients with failed weaning from prolonged IMV is feasible and can facilitate the decannulation process. Patients successfully completing this process show good survival rates and few complications.

Serial Weekly Measurements of the Timed Inspiratory Effort Index Can Predict Successful Prolonged Weaning.

BACKGROUND: Patients who require prolonged weaning from mechanical ventilation represent a major challenge in intensive care, and the timed inspiratory effort (TIE) index has been shown to be a clinically valuable tool to predict weaning success. OBJECTIVE: To evaluate whether weekly serial measurements of the TIE index can predict the success in prolonged weaning. METHODS: A prospective observational study in which the subjects who started the weaning process off mechanical ventilation underwent weekly measurements of the TIE index. The area under the receiver operating characteristic curve was used to evaluate the accuracy of the TIE index as a predictor of weaning success. A multivariate Cox regression model was developed to test the association of TIE index values of ≥1.0 cm H2O/s with a failure of weaning. RESULTS: Seventy subjects were selected. Their median (IQR) age was 72 (62-78) y, the median (IQR) duration of mechanical ventilation was 17.5 (14-28) d, and the median (IQR) APACHE II (Acute Physiology and Chronic Health Evaluation) II score was 28 (24-31). Thirty-five of the 70 subjects (50%) died, 22 of them after successful weaning. A total of 224 tests were performed over 56 d. The area under the receiver operating characteristic curve of the TIE index was 0.93. In the analysis of the probability of success during the follow-up (Kaplan-Meier method), a significant difference was obtained in favor of those with a TIE index of ≥ 1.0 cm H2O/s (53% vs 32%, P = .030). In the multivariate Cox regression analysis, values of the TIE index ≥ 1.0 cm H2O/s revealed an inverse, strong, and independent association with failure (hazard ratio 0.36, 95% CI 0.15-0.91; P = .030). The following variables were also found to have an independent but direct association with failure: age and length of time before weaning. CONCLUSIONS: When measured weekly, a TIE index of ≥1.0 cm H2O/s was a good predictor of success in subjects who required prolonged weaning in our hospital.

Person-centred care during prolonged weaning from mechanical ventilation, nurses' views: an interview study.

OBJECTIVE: To determine: 1) if the three elements of person-centred care (initiating, working and safeguarding the partnership) were present, and 2) to identify evidence of barriers to person-centred care during prolonged weaning from mechanical ventilation. RESEARCH METHODOLOGY: Secondary analysis of semi structured interviews with 19 critical care nurses using theoretical thematic analysis. SETTING: This study was conducted in three Swedish intensive care units, one in a regional hospital and two in a university hospital. FINDINGS: Three themes and nine subthemes related to person-centred care were identified. The three themes included: 1) 'finding a person behind the patient' related to the 'initiating the partnership' phase, 2) 'striving to restore patient́s sense of control' related to 'working the partnership' phase and 3) 'impact of patient involvement' related to 'safeguarding the partnership' phase of person-centred care'. Additionally a further theme 'barriers to person-centred care' was identified. CONCLUSION: We found evidence of all three person-centred care routines. Barriers to person-centred care comprised of lack team collaboration and resources. Facilitating patients to actively participate in decision-making during the weaning process may optimise weaning outcomes and warrants further research.

Electrical impedance tomography for predicting failure of spontaneous breathing trials in patients with prolonged weaning.

BACKGROUND: Spontaneous breathing trials (SBTs) on a T-piece can be difficult in patients with prolonged weaning because of remaining de-recruitment phenomena and/or insufficient ventilation. There is no clinically established method existent other than experience for estimating whether an SBT is most probably beneficial. Electrical impedance tomography (EIT) is a clinical useful online monitoring technique during mechanical ventilation, particularly because it enables analysis of effects of regional ventilation distribution. The aim of our observational study was to examine if EIT can predict whether patients with prolonged weaning will benefit from a planned SBT. METHODS: Thirty-one patients were examined. Blood gas analysis, vital parameter measurements, and EIT recordings were performed at three time points: (1) baseline with pressure support ventilation (PSV) (t0), (2) during a T-piece trial (t1), and (3) after resumption of PSV (t2). Calculation of EIT parameters was performed, including the impedance ratio (IR), the tidal variation of impedance (TIV), the changes in end-expiratory lung impedance (ΔEELI), the global inhomogeneity index (GI), and the regional ventilation delay (RVD) index with use of different thresholds of the percentage inspiration time (RVD40, RVD60, RVD80). The predictive power of the baseline GI with regard to clinical impairment of an SBT was analyzed by means of ROC curves. Clinical deterioration was assumed when tidal volume was decreased by at least 20 ml after the T-piece trial, measured at t2. RESULTS: Partial pressure of arterial oxygen significantly decreased at t1 (71 ± 15 mmHg) compared with t0 (85 ± 17 mmHg, p < 0.05) and t2 (82 ± 18 mmHg, p < 0.05). The IR trended toward higher values during t1. At t1, TIV and ΔEELI significantly decreased. The GI was significantly increased at t1 (t0 59.3 ± 46.1 vs t1 81.5 ± 62.5, p = 0.001), as were all RVD indexes. Assuming a GI cutoff value of >40, sensitivity of 85% and specificity of 50% were reached for predicting an increased future tidal volume. CONCLUSIONS: EIT enables monitoring of regional ventilation distribution during SBTs and is suitable to estimate whether an SBT probably will be beneficial for an individual patient. Therefore, the application of EIT can support clinical decisions regarding patients in the phase of prolonged weaning.

Is non-thyroidal illness syndrome a predictor for prolonged weaning in intubated chronic obstructive pulmonary disease patients?

INTRODUCTION: Non-thyroidal illness syndrome (NTIS) is considered to be associated with adverse outcomes in intensive care unit (ICU) patients. In this study, we evaluated the association between NTIS and prolonged weaning in chronic obstructive pulmonary disease (COPD) patients admitted to the ICU. MATERIALS AND METHODS: In total, 125 patients with COPD admitted to our ICU who underwent invasive mechanical ventilation (MV) were enrolled. We collected each patient's baseline characteristics including Acute Physiology and Chronic Health Evaluation (APACHE) II score, body mass index (BMI), and thyroid hormones 24 h after ICU admission. The presence of pulmonary infection was also recorded. The primary outcome was prolonged weaning, defined as patients who failed at least three weaning attempts or required > 7 days of weaning after the first spontaneous breathing trial. RESULTS: Of the 127 patients studied, 64 had normal thyroid function tests and 61 had NTIS. Patients with NTIS had significantly higher APACHE II scores, prolonged weaning, and pulmonary infection. Patients with NTIS had a higher risk for prolonged weaning (odds ratio, OR = 3.21; 95% CI = 1.31-7.83).The presence of pulmonary infection was also an independent risk factors for prolonged weaning. CONCLUSIONS: NTIS may be an independent predictor for prolonged weaning in intubated COPD patients.

Clinical study of rapid shallow breathing index as the switching point for sequential ventilation for patients with prolonged weaning after thoracolaparotomy / 中华急诊医学杂志

Objective To investigate the influencing factors of successfully switching to sequential ventilation in patients with prolonged weaning due to acute respiratory failure (ARF) after thoracolaparotomy based on the initial rapid shallow breathing index (RSBI) at 60 min after spontaneous breathing trial (SBT), namely, the f/VT optimal value range of 80-120 times/ (min · L), thus providing the basis for determining the ideal timing of weaning in clinical practice.Methods A prospective observational study of sequential ventilation [RSBI during the initial SBT (60 min), 80-120 breaths/ (min · L)] was carried out in 42 patients on mechanical ventilation (≥ 48 h) due to post-thoracolaparotomy ARF in the ICUs.According to the duration of the mechanical ventilation, the patients were divided into 2 groups : successfully prolonged weaning group (≥ 7 days, n =24) and refractory weaning group (＜ 7 days, n =18).The patients with cardiac failure, aged less 18 or over 80, with hepatic dysfunction, or those needing gastrointestinal decompression after esophageal surgery or upper abdomen surgery were excluded.The demographics, APACHE Ⅱ scores and duration of mechanical ventilation of both groups were recorded, and the respiratory work and oxygen metabolism variables before the switch to sequential ventilation (within 24 hours after admission to ICU) and at the time of switching (24 hours in the ICU after admission) were recorded, respectively: clinical puhnonary infection score (CPIS), assessment of cough severity, pH, PaO2, PaCO2 and PaO2/FiO2;hemodynamic and microcirculation-related variables: HR, MAP, fluid balance, BNP and Lac;endocrine and metabolism variables : Hb, ALB and random serum cortisol (COR).The clinical features and the changes of the above-mentioned variables before and at the time of switching were compared between both groups.The independent sample t test was used for the single factor comparison and Mann-Whitney U test was applied to the non-normal distributions.The Fisher exact probability test was used for the single factor comparison of ranked data such as categorical variables.Results There were no significant differences in age, gender and severity of disease between two groups (P ＞ 0.05);the successfully prolonged weaning group had longer duration of invasive mechanical ventilation and ICU stay compared with the refractory weaning group (P ＜ 0.05).There were significant differences in cough severity, PaCO2, pH, HR and fluid balance between two groups before switching (P ＜ 0.05).Compared with those before switching, in the refractory weaning group there were marked decrease in Lac (P ＜ 0.05), obvious increase in cough severity, pH, Hb and ALB (P ＜ 0.05), but there was no significant difference in COR (P ＞ 0.05);while in the successfully delayed weaning group, there were significant decrease in CPIS, PaCO2, HR, MAP, BNP, fluid balance and Lac (P ＜ 0.05), and cough severity, pH, ALB and COR showed an upward trend (P ＜ 0.05).Conclusions The key of successful sequential ventilation is within the values of RSBI ranging from 80 to 120 times/ (min · L) during the initial SBT (60 min) selected as the switching point in patients with prolonged weaning after thoracolaparotomy.The major influencing factors for determining the ideal timing of switching include the matching status between respiratory endurance and respiratory work, the balance between myocardial strength and both cardiac preload and afterload, the severe disease associated with adrenal insufficiency, and malnutrition.

Critical care nurses management of prolonged weaning: an interview study.

BACKGROUND: For most critically ill patients requiring mechanical ventilation in the intensive care unit (ICU) weaning is uncomplicated. For the remainder, weaning is a challenge and may result in further complications and increased risk of mortality. Critical care nurses (CCNs) require substantial knowledge and experience to manage patients experiencing prolonged weaning. AIM: The aim of this study was to explore CCNs approach for management of patients experiencing prolonged weaning in the ICU. DESIGN: A descriptive qualitative design. METHODS: Semi-structured interviews with 19 experienced CCNs were conducted. Data were analysed using content analysis. RESULTS: Participants used various strategies for weaning that were grouped into four categories: individualized planning for the weaning process, assessing patient's capacity, managing the process and team interaction. The overall theme that emerged was: CCNs drive the weaning process using both a patient centred and targeted approach. CONCLUSION: CCNs in these ICUs performed weaning using a patient centred approach to plan, initiate, assess and establish a holistic weaning process. Team collaboration among all health care practitioners was important. CCNs have a key role in prioritizing weaning and driving the process forward. RELEVANCE TO CLINICAL PRACTICE: Closeness to the patient and a key role in management of the mechanical ventilated patient in ICU gives the CCN unique potential to develop and create models and tools for prolonged weaning. These tools, specially designed for patients undergoing prolonged weaning, would give focus on continuous planning, collaborating, managing and evaluation in the process of liberating patients from mechanical ventilation.