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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., Competing Interests: Declaration of competing interest The authors have no conflicts of interest to declare., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

This study investigated fluid removal strategies for critically ill patients with fluid overload on mechanical ventilation. Traditionally, a negative fluid balance (FB) is aimed for. However, this approach can have drawbacks. Here, we compared a new approach, namely removing fluids until patients become fluid responsive (FR) to the traditional empiric negative balance approach. Twelve patients were placed in each group (n = 24). FR assessment was performed using passive leg raising (PLR). Both groups maintained stable blood pressure and heart function during fluid management. Notably, the FR group weaned from the ventilator significantly faster than negative FB group (both for a spontaneous breathing trial (14 h vs. 36 h, p = 0.031) and extubation (26 h vs. 57 h, p = 0.007); the difference in total ventilator time wasn't statistically significant (49 h vs. 62 h, p = 0.065). Additionally, FR group avoided metabolic problems like secondary alkalosis and potential hypokalemia seen in the negative FB group. FR-guided fluid-removal in fluid overloaded mechanically ventilated patients was a feasible, safe, and maybe superior strategy in facilitating weaning and disconnection from mechanical ventilation than negative FB-driven fluid removal. FR is a safe endpoint for optimizing cardiac function and preventing adverse consequences during fluid removal., Competing Interests: Declaration of competing interest The authors RC, PB, FM, CG, EK, GH, and JB declare no financial interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Despite advances in weaning protocols, extubation failure (EF) is associated with poor outcomes. Many predictors of EF have been proposed, including hypercapnia at the end of the spontaneous breathing test (SBT). However, performing arterial blood gases at the end of SBT is not routinely recommended, whereas end-tidal carbon dioxide (EtCO2) can be routinely monitored during SBT. We aimed to evaluate the clinical utility of EtCO2 to predict EF. Patients undergoing planned extubation were eligible. Non-inclusion criteria were tracheostomy and patients extubated after successful T-tube SBT. We recorded clinical data and EtCO2 in 189 patients during a successful one-hour low pressure support SBT. EtCO2 measured before successful SBT was lower in patients with EF compared to those with successful extubation (27 [24-29] vs 30 [27-47] mmHg, p = 0.02), while EtCO2 measured at five minutes and at the end of the SBT was not different between the two groups (26 [22-28] vs. 29 [28-49] mmHg, p = 0.06 and 26 [26-29] vs. 29 [27-49] mmHg, p = 0.09, respectively). Variables identified by multivariable analysis as independently associated with EF were acute respiratory failure as the cause of intubation and ineffective cough. Our study suggests that recording EtCO2 during successful SBT appears to have limited predictive value for EF., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

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., Competing Interests: Declaration of Competing Interest The Authors declare that there is no conflict of interest., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: Weaning individuals from mechanical ventilation (MV) is a challenge to physicians. Respiratory failure is the main reason for weaning failure (WF), but heart failure plays a pivotal role as well. Transesophageal Doppler (TED) is a minimally invasive method of hemodynamic tracking with fewer problems. The study authors evaluated the role of TED in predicting WF., Design: An observational study., Setting: A university teaching hospital., Participants: Weaning individuals., Interventions: TED was applied before initiating the spontaneous breathing trial (SBT). Hemodynamic parameters, arterial blood gases, and TED (peak velocity [PV], cardiac output [COP]) were reported while cases were on MV before initiating the SBT, and at the successful completion of SBT. Succeeded (group S) and failed individuals (group F, who needed reintubation within 48 hours) were compared. The sensitivity, specificity, and area under the receiver operating curve were calculated. A subgroup of patients with cardiac comorbidities and impaired cardiac contractility was further analyzed., Measurements and Main Results: The authors included 39 critically ill patients for weaning from MV. The reintubation rate was 54.8%. In patients with cardiac morbidity, delta change (dC) in PV and COP as predictors of WF showed 100% sensitivity and specificity, with 18% and 14% cut-offs after initiating the SBT (dC between the beginning and end of the successful SBT), respectively. Central venous oxygen saturation revealed a significant difference between patients with cardiac morbidity and noncardiac patients with lower sensitivity and specificity in the prediction of WF., Conclusions: TED could be a helpful method for the weaning of patients with cardiac morbidity from MV. The dC in PV and COP >18% and >14% were significant predictors of WF in these subjects, respectively., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: Physiological data suggest that T-piece and zero pressure support (PS0) ventilation both accurately reflect spontaneous breathing conditions after extubation. These two types of spontaneous breathing trials (SBTs) are used in our Intensive Care Unit to evaluate patients for extubation readiness and success but have rarely been compared in clinical studies., Materials and Methods: We performed a prospective observational study to confirm the hypothesis that 1-hour T-piece SBT and 1-h PS0 zero PEEP (ZEEP) SBT are associated with similar rates of reintubation at day 7 after extubation. A non-inferiority approach was used for sample size calculation., Results: The cohort consisted of 529 subjects invasively ventilated for more than 24 h and extubated after successful 1-hour T-piece SBT (n = 303, 57%) or 1-h PS0 ZEEP SBT (n = 226, 43%). The reintubation rate at day 7 was 14.6% with PS0 ZEEP and 17.5% with T-piece (difference - 2.6% [95% confidence interval, -8.3% to 4.3%]; p = 0.40). The reasons for reintubation did not differ significantly when compared between patients with 1-h PS0 ZEEP SBT and patients with 1-hour T-piece SBT., Conclusion: Our results suggest that successful 1-hour T-piece and 1-h PSO ZEEP SBTs are associated with similar reintubation rates at day 7., Competing Interests: Declaration of Competing Interest None., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: Weaning from mechanical ventilation is a key component of intensive care treatment; however, this process may be prolonged as some patients require care at specialised centres. Current data indicate that weaning from invasive mechanical ventilation is successful in approximately 65% of patients; however, data on long-term survival after discharge from a weaning centre are limited., Materials and Methods: We analysed predictors of survival among 597 patients (392 men, mean age 68 ± 11) post-discharge from a specialised German weaning centre., Results: Complete weaning from mechanical ventilation was achieved in 407 (57.8%) patients, and 106 patients (15.1%) were discharged with non-invasive ventilation; thus, prolonged weaning was successful in 72.9% of the patients. The one-year and five-year survival rates post-discharge were 66.5% and 37.1%, respectively. Age, duration of mechanical ventilation, certain clusters of comorbidities, and discharged with mechanical ventilation significantly influenced survival (p < .001). Completely weaned patients who were discharged with a tracheostomy had a significantly reduced survival rate than did those who were completely weaned and discharged with a closed tracheostomy (p = .004)., Conclusions: The identified predictors of survival after prolonged weaning could support therapeutic strategies during patients' intensive care unit stay. Patients should be closely monitored after discharge from a weaning centre., (Copyright © 2020. Published by Elsevier Inc.)

The COVID-19 pandemic is spreading globally. COVID-19 has an effect on the systemic state, cardiopulmonary function and primary disease of patients undergoing surgery. COVID-19's high contagiousness makes anesthesia and intraoperative management more difficult. This expert consensus aims to comprehensively introduce the application of perioperative ultrasound in COVID-19 patients, including pulmonary ultrasound and anesthesia management, ultrasound and airway management, ultrasound-guided regional anesthesia and echocardiography for COVID-19 patients., (Copyright © 2020. Published by Elsevier Inc.)

Purpose: Rapid shallow breathing index (RSBI) is a commonly used index for predicting the outcome of spontaneous breathing trial (SBT). Ultrasound is a non-invasive technique for assessing diaphragm activity and function. This study aimed to investigate changes in diaphragm activity during SBT, and to compare diaphragm function between patients with and without SBT success., Materials and Methods: Forty-five patients undergoing SBT were enrolled. Thickening fraction of the diaphragm was assessed during tidal breathing (TFdi tidal ), and RSBI was measured during 30 min of SBT. Diaphragm function measured by maximum TFdi (TFdi max ) and diaphragmatic excursion (DE max ) was also evaluated., Results: TFdi tidal and RSBI significantly increased during SBT (TFdi tidal0 vs. TFdi tidal30  = 29.8 ± 13.8 vs. 37.4 ± 13.0%; p < .001, and RSBI 0 vs. RSBI 30  = 64.8 ± 25.9 vs.70.8 ± 29.1 breaths/min/L; p = .034). In SBT failure (n = 13), there was no significant difference in TFdi tidal compared to SBT success, except at the beginning of the trial (p = .043); however, RSBI significantly increased throughout SBT. No differences in TFdi max or DE max were observed between groups., Conclusions: Patient inspiratory efforts significantly increased during SBT. TFdi tidal measured by diaphragm ultrasound could not distinguish between patients with SBT success and failure. RSBI was significantly higher during SBT in patients with SBT failure., (Copyright © 2019. Published by Elsevier Inc.)

Purpose: Optimizing pressure support ventilation (PSV) can improve patient-ventilator interaction. We conducted a two-center, randomized cross-over study to determine whether automated PSV lowers asynchrony rate during difficult weaning from mechanical ventilation., Methods: Thirty patients failing the first weaning attempt were randomly ventilated for 2 three-hour consecutive periods with: 1)PSV managed by physicians (convPSV); 2)PSV managed by Smartcare® (autoPSV). These 2 periods were applied in the afternoon and overnight, for a 12-h total study time. Two independent clinicians offline analyzed ventilator waveforms to compute asynchrony index(AI)., Results: AI was lower during autoPSV than during convPSV (medians[interquartile ranges] 5.1[2.6-9.5]% vs. 7.3[2.3-13.4]%, p = 0.02), without changes in the proportion of patients with AI>10%(p = 0.31). Pressure support (PS) variability was higher during autoPSV (p < 0.001), but average PS did not vary. In patients with baseline PS > 12 cmH 2 O (n = 15), PS and tidal volume were lower with autoPSV (12 [10-15]cmH 2 O vs. 15 [14-18]cmH 2 O,p = 0.003; 7.2[6.2-8.3]ml/Kg vs. 8.2[7.1-9.1]ml/Kg, p = 0.02) and AI reduction was driven by lower tidal volume (p = 0.03). In patients with baseline PS ≤ 12 cmH 2 O, AI reduction during autoPSV was mediated by increased PS variability (p = 0.04)., Conclusion: During difficult weaning, autoPSV improves patient-ventilator interaction by lowering tidal volume and enhancing PS variability. In expert centres, however, the size effect of the intervention appears clinically small, likely because physicians themselves adequately limit PS and tidal volume., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: To identify, describe and discuss the parameters used to predict weaning from mechanical ventilation and extubation outcomes., Methods: Systematic review of scientific articles using four electronic databases: PubMed, Embase, PEDro and Cochrane Library. Search terms included "weaning", "extubation", "withdrawal" and "discontinuation", combined with "mechanical ventilation" and "predictive factors", "predictive parameters" and "predictors for success". In this study, we included original articles that presented predictive factors for weaning or extubation outcomes in adult patients and not restricted to a single disease. Articles not written in English were excluded., Results: A total of 43 articles were included, with a total of 7929 patients and 56 different parameters related to weaning and extubation outcomes. Rapid Shallow Breathing Index (RSBI) was the most common predictor, discussed in 15 studies (2159 patients), followed by Age and Maximum Inspiratory Pressure in seven studies. The other 53 parameters were found in less than six studies., Conclusion: There are several parameters used to predict weaning and extubation outcomes. RSBI was the most frequently studied and seems to be an important measurement tool in deciding whether to wean/extubate a patient. Furthermore, the results demonstrated that weaning and extubation should be guided by several parameters, and not only to respiratory ones., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: To compare the effects of adding a progressive multimodal rehabilitation program to usual care (MRP + UC) versus UC alone on 1) functional mobility, strength, endurance and 2) ventilator weaning and discharge status of patients with ICU-acquired weakness (ICUAW) receiving prolonged mechanical ventilation (PMV)., Methods: Randomized pilot trial of an individualized MRP + UC versus UC in middle-aged and older ICU survivors with ICUAW receiving PMV. Outcomes compare changes in strength, mobility, weaning success and discharge home from a long-term acute care hospital (LTACH) between the groups., Results: Eighteen males and 14 females (age 60.3 ± 11.9 years) who received PMV for ≥14 days were enrolled. Despite no significant differences between groups in the changes in handgrip, gait speed, short physical performance battery or 6-min walk distance after treatment, the MRP + UC group had greater weaning success (87% vs. 41%, p < 0.01), and more patients discharged home than UC (53 vs. 12%, p = 0.05). Post hoc analyses, combining patients based on successful weaning or discharge home, demonstrated significant improvements in strength, ambulation and mobility., Conclusion: The addition of an MRP that improves strength, physical function and mobility to usual physical therapy in LTACH patients with ICUAW is associated with greater weaning success and discharge home than UC alone., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: We sought to examine variation in long-term acute care hospital (LTACH) quality based on 90-day in-hospital mortality for patients admitted for weaning from mechanical ventilation., Methods: We developed an administrative risk-adjustment model using data from Medicare claims. We validated the administrative model against a clinical model using data from LTACHs participating in a 2002 to 2003 clinical registry. We then used our validated administrative model to assess national variation in 90-day in-hospital mortality rates in LTACHs from 2013., Results: The administrative risk-adjustment model was derived using data from 9447 patients admitted to 221 LTACHs in 2003. The model had good discrimination (C statistic=0.72) and calibration. Compared to a clinically derived model using data from 1163 patients admitted to 14 LTACHs, the administrative model generated similar performance estimates. National variation in risk-adjusted mortality was assessed using data from 20,453 patients admitted to 380 LTACHs in 2013. LTACH-specific risk-adjusted mortality rates varied from 8.4% to 48.1% (median: 24.2%, interquartile range: 19.7%-30.7%)., Conclusions: LTACHs vary widely in mortality rates, underscoring the need to better understand the sources of this variation and improve the quality of care for patients requiring long-term ventilator weaning., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Introduction: Mechanical ventilatory support is life-saving therapy for patients with respiratory failure in intensive care units (ICU) but is linked to ventilator-associated pneumonia and other nosocomial infections. Interventions that improve the efficiency of weaning from mechanical ventilation may improve patient outcomes., Objective: To determine whether inhaled budesonide decreases time-to-weaning in COPD stage 4 difficult-to-wean patients and reduces the release of pro-inflammatory cytokines in ICU patients., Materials and Methods: We recruited 55 difficult-to-wean COPD patients (Stage 4) within the ICU of the Masih Daneshvari Hospital. Subjects were randomly assigned to receive inhaled budesonide (0.5mg/day) or placebo (normal saline). Dynamic compliance and BAL cytokines were measured., Results: Budesonide significantly reduced the number of days on MV (days-to-weaning=4.6±1.6days) compared to that seen in the control group (7.2±2.7days, p=0.014). Dynamic compliance was significantly improved in the budesonide group on days 3 (p=0.018) and 5 (p=0.011) The levels of CXCL-8 and IL-6 diminished on days 3-5 after start of budesonide (p<0.05)., Conclusion: In COPD patients on MV, nebulized budesonide was associated with reduced BAL CXCL8 and IL-6 levels and neutrophil numbers as well as an improvement in ventilatory mechanics and facilitated weaning., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objective: The optimal timing of extubation following cardiac surgery is currently unknown. Protocols implemented in order to achieve a rapid extubation may achieve this goal, but not prove beneficial in terms of outcomes., Design: A prospective clinical trial., Setting: Tertiary care cardiac surgical intensive care unit., Participants: Adult cardiac surgical patients., Interventions: Implementation of an 8-tier multidisciplinary rapid weaning protocol., Measurements and Main Results: Ventilator times 6 months prior to and 6 months after implementation of the protocol were measured. Outcomes associated with ventilator times were measured by dividing the patients into tertiles (<6 hours, 6-12 hours, >12 hours). Primary outcomes were intensive care unit (ICU) and hospital length of stay. Secondary outcomes included mortality at 30 days and other major morbidities. In all, 459 patients were included in the study. With implementation of the protocol, median ventilation times decreased from 7.4 hours (interquartile range, IQR = 3rd quartile - 1st quartil e= 6.72 hours) to 5.73 hours (IQR = 5.51 hours) (p < 0.0001). However, median ICU length of stay in patients who achieved extubation within 6 hours increased to 49.45 hours (IQR = 44.4) from 40.3 (IQR = 25.6) (p = 0.0017). Median hospital length of stay was not significantly changed due to the protocol in any ventilation tertile (p = 0.650)., Conclusions: Decreasing intubation times to <6 hours in postsurgical cardiac patients is obtainable with implementation of a multidisciplinary rapid weaning protocol. However, patients extubated within 6 hours had increased ICU length of stay and no difference in hospital length of stay with this intervention., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: A commercially available decision support system (DSS) provides guidance for setting inspiratory pressure support (PS) to maintain work of breathing (WOB/min), breathing frequency (f), and tidal volume (V T ) in proper clinical ranges (VentAssist™). If these values are outside the proper clinical range patients may suffer fatigue, atrophy, hypoventilation, hyperventilation, volutrauma, or V T deficiency. The purpose of our study was to evaluate the increase of the percentage of breaths in the targeted clinical ranges when the DSS guidance for setting the PS was followed., Materials and Methods: The study included 43 intubated adults with respiratory failure in an academic medical intensive care unit. Each of the patients had received ventilatory support for >24h with no weaning trials attempted. Clinicians switched the ventilator to PS then proceeded to utilize the guidance recommended by the DSS for setting PS for 21 patients (intervention group); while the clinicians caring for the remaining 23 patients did not have access to the DSS (control group)., Results: The use of a DSS to set PS level increased the percentage of breaths in the targeted clinical range [28% to 48%, p value<0.0001]. An unexpected result was that while following the DSS 18 of the 21 patients were rapidly weaned to minimal ventilator settings within 46±38min; however, when the DSS was not available weaning to minimal ventilator settings lasted 21±12h [p value<0.0001]., Conclusions: The DSS is successful at assisting clinicians on how to set PS specific to a patient's individual demands (V T and f) while accounting for their breathing effort (WOB/min). The DSS appears to promote rapid weaning of PS to minimal ventilator settings when appropriate., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: Sedation in extracorporeal membrane oxygenation (ECMO) is challenging. Patients require deep sedation because of extremely high respiratory rates and increased work of breathing ("Drowning Syndrome") resulting in altered intra-thoracic pressure and reduced pump flow associated with hemodynamic compromise and decreased oxygenation. However, deep sedation impedes essential active rehabilitation with physical therapy., Methods: We reviewed data on 3 ECMO patients for whom we used a novel approach to replace continuous drips with periodic sedation/paralysis. Initially our patients were on high dose narcotics, propofol, and dexmedetomidine and unable to interact and breathe comfortably. IV narcotics were weaned over 24h and were replaced by methadone. Dexmedetomidine was continued in order to block hyperadrenergic events. Propofol was weaned at a prescribed rate. When patients demonstrated agitation, decreased pump flow and hemodynamic compromise, diazepam was given in combination with a paralytic., Results: By replacing IV narcotic and propofol, with PRN diazepam and vecuronium, patients were off continuous drips in 1week and were able to actively participate in physical therapy., Conclusion: Allowing patients to wake up by rapid weaning of continuous narcotics and anesthetic agents using Dexmedetomidine and periodic paralysis to favorably alter hemodynamics is a successful method to wean deep sedation in ECMO., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The management of the ventilator in patients with chronic obstructive pulmonary disease (COPD) and acute respiratory distress syndrome (ARDS) has a dramatic effect on the overall outcome. The incidence of COPD is increasing as the US population grows older. The most effective means to deal with pulmonary complications is to avoid them, but both COPD and ARDS have evidence-based interventions that have been shown to improve outcomes. Pulmonary complications affect up to 40% of patients, and their occurrence is associated with an increased duration of hospital stay, and an increased mortality., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Introduction: Implementation of a weaning protocol is related to better patient prognosis. However, new approaches may take several years to become the standard of care in daily practice. We conducted a prospective cohort study to investigate the effectiveness of a multifaceted strategy to implement a protocol to wean patients from mechanical ventilation (MV) and to evaluate the weaning success rate as well as practitioner adherence to the protocol., Methods: We investigated all consecutive MV-dependent subjects admitted to a medical-surgical intensive care unit (ICU) for >24h over 7years. The multifaceted strategy consisted of continuing education of attending physicians and ICU staff and regular feedback regarding patient outcomes. The study was conducted in three phases: protocol development, protocol and multifaceted strategy implementation, and protocol monitoring. Data regarding weaning outcomes and physician adherence to the weaning protocol were collected during all phases., Results: We enrolled 2469 subjects over 7years, with 1,943 subjects (78.7%) experiencing weaning success. Physician adherence to the protocol increased during the years of protocol and multifaceted strategy implementation (from 38% to 86%, p<0.01) and decreased in the protocol monitoring phase (from 73.9% to 50.0%, p<0.01). However, during the study years, the weaning success of all subjects increased (from 73.1% to 85.4%, p<0.001). When the weaning protocol was evaluated step-by-step, we found high adherence for noninvasive ventilation use (95%) and weaning predictor measurement (91%) and lower adherence for control of fluid balance (57%) and daily interruption of sedation (24%). Weaning success was higher in patients who had undergone the weaning protocol compared to those who had undergone weaning based in clinical practice (85.6% vs. 67.7%, p<0.001)., Conclusions: A multifaceted strategy consisting of continuing education and regular feedback can increase physician adherence to a weaning protocol for mechanical ventilation., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: Speaking valves (SV) are used infrequently in tracheostomised ICU patients due to concerns regarding their putative effect on lung recruitment. A recent study in cardio-thoracic population demonstrated increased end-expiratory lung volumes during and post SV use without examining if the increase in end-expiratory lung impedance (EELI) resulted in alveolar recruitment or potential hyperinflation in discrete loci., Materials and Methods: A secondary analysis of Electrical Impedance Tomography (EIT) data from a previous study was conducted. EELI distribution and tidal variation (TV) were assessed with a previously validated tool. A new tool was used to investigate ventilated surface area (VSA) and regional ventilation delay (RVD) as indicators of alveolar recruitment., Results: The increase in EELI was found to be uniform with significant increase across all lung sections (p<0.001). TV showed an initial non-significant decrease (p=0.94) with subsequent increase significantly above baseline (p<0.001). VSA and RVD showed non-significant changes during and post SV use., Conclusions: These findings indicate that hyperinflation did not occur with SV use, which is supported by previously published data on respiratory parameters. These data along with obvious psychological benefits to patients are encouraging towards safe use of SVs in this critically ill cardio-thoracic patient population., Trial Registration: Anna-Liisa Sutt, Australian New Zealand Clinical Trials Registry (ANZCTR)., Actrn: ACTRN12615000589583. 4/6/2015., (Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.)

Neonates with congenital diaphragmatic hernia are among the more complex patients to support with mechanical ventilation. They have particular features that add to the difficulties already present in the neonatal patient. A ventilation strategy tailored to the patient's underlying physiology rather than mode of ventilation is a crucial issue for clinicians treating these delicate patients., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objective: Weaning from veno-arterial extracorporeal life support is challenging. The objective of this trial was to investigate the endothelial and hemodynamic effects of levosimendan in cardiogenic shock patients supported with veno-arterial extracorporeal life support., Design: This was a prospective observational trial., Setting: Cardiovascular intensive care unit of a large tertiary care university hospital in Monza, Italy., Participants and Interventions: Flow-mediated dilatation of the brachial artery and hemodynamic parameters were assessed in 10 cardiogenic shock patients supported with veno-arterial extracorporeal life support, before and after the infusion of levosimendan., Measurements and Results: Flow-mediated dilatation increased both as absolute value and as a percentage after levosimendan, from 0.10±0.12 to 0.61±0.21 mm (p<0.001) and from 3.2±4.2% to 17.8±10.4% (p<0.001), respectively. Cardiac index increased from 1.93±0.83 to 2.64±0.97 L/min/m 2 (p = 0.008) while mixed venous oxygen saturation increased from 66.0% to 71.5% (p = 0.006) and arterial lactate levels decreased from 1.25 to 1.05 mmol/L (p = 0.004) without significant variations in arterial oxygen saturation or hemoglobin levels. This made it possible for clinicians to reduce extracorporeal membrane oxygenation blood flow from 1.92±0.65 to 1.12±0.49 L/min/m 2 (p<0.001)., Conclusion: In conclusion, in the authors' study population of adult cardiogenic shock patients supported with veno-arterial extracorporeal life support, their observations supported the use of levosimendan to improve endothelial function and hemodynamics and facilitate weaning from the extracorporeal support., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Intensive care units are a stressful milieu for patients, particularly when under mechanical ventilation which they refer to as inhumane and anxiety producing. Anxiety can impose harmful effects on the course of recovery and overall well-being of the patient. Resulting adverse effects may prolong weaning and recovery time. Music listening, widely used for stress release in all areas of medicine, tends to be a reliable and efficacious treatment for those critically ill patients. It can abate the stress response, decrease anxiety during mechanical ventilation, and induce an overall relaxation response without the use of medication. This relaxation response can lower cardiac workload and oxygen consumption resulting in more effective ventilation. Music may also improve sleep quality and reduce patient's pain with a subsequent decrease in sedative exposure leading to an accelerated ventilator weaning process and a speedier recovery., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: Weaning failure and prolonged mechanical ventilation are associated with increased morbidity, cost of care, and high mortality rates. In the last few years, cardiac performance has been recognized as a common etiology of weaning failure, and growing evidence suggests that left ventricular diastolic dysfunction is a key factor that determines weaning outcomes. Therefore, we performed a systematic review and a meta-analysis to evaluate whether diastolic dysfunction in the critically ill patient subjected to mechanical ventilation is an independent predictor of weaning failure., Materials and Methods: We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, LILACS, Google Scholar, and ClinicalTrials.gov from inception to September 2014, along with conferences proceeding from January 2005 through September 2014, and included Observational Studies and Randomized Clinical Trials evaluating predictors of weaning failure., Results: Ten studies were included in the systematic review; and 7, in the meta-analysis (6 observational studies and 1 randomized controlled trial). Patients who developed weaning failure had a higher E/e' ratio when compared with those who did not (mean difference, 2.65; 95% confidence interval, 0.52-4.79; P= .01); however, there was no difference in the E/A ratio (mean difference, 0.07; 95% confidence interval, -0.04 to 0.18; P= .22). Both the E/e' and E/A ratios were associated with weaning-induced pulmonary edema at the end of a spontaneous breathing trial., Conclusion: A higher E/e' ratio is significantly associated with weaning failure, although a high heterogeneity of diastolic dysfunction criteria and different clinical scenarios limit additional conclusions linking diastolic dysfunction with weaning failure., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: This study aims to compare the effectiveness of weaning with adaptive support ventilation (ASV) incorporating progressively reduced or constant target minute ventilation in the protocol in postoperative care after cardiac surgery., Material and Methods: A randomized controlled unblinded study of 52 patients after elective coronary artery bypass surgery was carried out to determine whether a protocol incorporating a decremental target minute ventilation (DTMV) results in more rapid weaning of patients ventilated in ASV mode compared to a protocol incorporating a constant target minute ventilation., Results: Median duration of mechanical ventilation (145 vs 309 minutes; P = .001) and intubation (225 vs 423 minutes; P = .005) were significantly shorter in the DTMV group. There was no difference in adverse effects (42% vs 46%) or mortality (0% vs 0%) between the 2 groups., Conclusions: Use of a DTMV protocol for postoperative ventilation of cardiac surgical patients in ASV mode results in a shorter duration of ventilation and intubation without evidence of increased risk of adverse effects., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: A proposal was made at the International Consensus Conference to classify weaning of patients in intensive care units from mechanical ventilation into simple, difficult, and prolonged weaning groups based on the difficulty and length of the weaning process. The objective of the present study was to determine the incidence and outcome of weaning according to these new categories., Methods: We examined the weaning of patients in intensive care units from mechanical ventilation in a prospective multicenter cohort study., Results: In total, 343 patients were included in the final analysis. Simple, difficult, and prolonged weaning occurred in 200 (58%), 99 (29%), and 44 (13%) patients, respectively. Hospital mortality rates were higher for patients in the prolonged weaning group than in the simple and difficult weaning groups. Multivariate analysis revealed that a lower Glasgow Coma Scale score (P < .014) and hypercapnia at the beginning of the first spontaneous breathing trial (P = .038) were independent predictors of prolonged weaning., Conclusions: Patients who experienced prolonged weaning had significantly higher mortality rates than patients who experienced either simple or difficult weaning. A lower Glasgow Coma Scale score and hypercapnia at the beginning of the weaning process were independent risk factors for prolonged weaning., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objective: Weaning from venoarterial extracorporeal membrane oxygenation (VA ECMO) usually is performed without clear guidelines; yet, patients still die after removal of extracorporeal circulation because of inadequate heart or end-organ recovery. The aim of the study was to address the weaning procedure, analyzing the hemodynamic and echocardiographic picture of patients weaned and to identify predictors of poor outcome among this population., Design: Observational study., Setting: University hospital., Participants: One hundred twenty-nine VA ECMO cases., Interventions: None., Measurements and Main Results: Forty-nine patients (38%) were weaned, 7 (5.4%) were bridged to a ventricular assist device, and 6 (5.2%) were listed for heart transplantation. Weaned patients showed a significant increase of pulse pressure (35 [0-50] mmHg before ECMO, 59 [53-67] mmHg at weaning, 61 [51-76] mmHg after ECMO (p<0.001]) and reduction of dose of inotropes (inotropic score [as defined in the text] 20 [14-40] before ECMO, 10 [3-15] at weaning, and 10 [5-15] after ECMO, p<0.001). Left ventricular ejection fraction (LVEF) increased from 19 (0-22.5)% before ECMO to 35 (22-55)% after ECMO (p<0.001). A significant improvement of right ventricular (RV) function was observed in weaned patients (RV dysfunction from 52% to 21%, p<0.001). Among weaned patients, 15 (31%) died. Patients who died after weaning had longer ECMO duration compared to discharged patients (8 [5-11] v 4 [2-6] days, p = 0.01) and more transfusions (22 [10-37] v 7 [0.5-15] units, p = 0.02); survival was lower in patients with central ECMO (postcardiotomy) compared to peripheral ECMO (p = 0.045). Mortality was higher in those with persistence of RV failure, continuous venovenous hemofiltration, higher inotropic score, lower systolic pressure, or higher leucocyte count at weaning., Conclusions: Successful weaning from ECMO is a multifaceted process, which encompasses consistent recovery of myocardial and end-organ function; LVEF, though improved, is still low at weaning. Hospital survival is correlated significantly to the duration of ECMO support and to bleeding complications., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: We sought to describe prevalence and care practices for patients experiencing prolonged mechanical ventilation (PMV), defined as ventilation for 21 or more consecutive days and medical stability., Methods: We provided the survey to eligible units via secure Web link to a nominated unit champion from April to November 2012. Weekly telephone and e-mail reminders were sent for 6 weeks., Results: Response rate was 215 (90%) of 238 units identifying 308 patients requiring PMV on the survey day occupying 11% of all Canadian ventilator-capable beds. Most units (81%) used individualized plans for both weaning and mobilization. Weaning and mobilization protocols were available in 48% and 38% of units, respectively. Of those units with protocols, only 25% reported weaning guidance specific to PMV, and 11% reported mobilization content for PMV. Only 30% of units used specialized mobility equipment. Most units referred to speech language pathologists (88%); use of communication technology was infrequent (11%). Only 29% routinely referred to psychiatry/psychology, and 17% had formal discharge follow-up services., Conclusions: Prolonged mechanical ventilation patients occupied 11% of Canadian acute care ventilator bed capacity. Most units preferred an individualized approach to weaning and mobilization with considerable variation in weaning methods, protocol availability, access to specialized rehabilitation equipment, communication technology, psychiatry, and discharge follow-up., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objective: The aim of this study was to determine the best predictors of successful extubation after cardiac surgery, by modifying the rapid shallow breathing index (RSBI) based on patients' anthropometric parameters., Design: Single-center prospective observational study., Setting: Two general intensive care units at a single research institute., Participants: Patients who had undergone uncomplicated cardiac surgery., Interventions: None., Measurements and Main Results: The following parameters were investigated in conjunction with modification of the RSBI: Actual body weight (ABW), predicted body weight, ideal body weight, body mass index (BMI), and body surface area. Using the first set of patient data, RSBI threshold and modified RSBI for extubation failure were determined (threshold value; RSBI: 77 breaths/min (bpm)/L, RSBI adjusted with ABW: 5.0 bpm×kg/mL, RSBI adjusted with BMI: 2.0 bpm×BMI/mL). These threshold values for RSBI and RSBI adjusted with ABW or BMI were validated using the second set of patient data. Sensitivity values for RSBI, RSBI modified with ABW, and RSBI modified with BMI were 91%, 100%, and 100%, respectively. The corresponding specificity values were 89%, 92%, and 93%, and the corresponding receiver operator characteristic values were 0.951, 0.977, and 0.980, respectively., Conclusions: Modified RSBI adjusted based on ABW or BMI has greater predictive power than conventional RSBI., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Purpose: The effectiveness of noninvasive positive pressure ventilation delivered by helmet (H-NPPV) as a weaning approach in patients with acute respiratory failure is unclear., Patients and Methods: We randomly and evenly assigned 64 patients intubated for acute respiratory failure to conventional weaning with invasive mechanical ventilation (IMV) or H-NPPV. The primary end point was a reduction in IMV duration by 6 days between the 2 groups. Secondary end points were the occurrence of ventilator-associated pneumonia and major complications, duration of mechanical ventilation and weaning, intensive care unit and hospital length of stay, and survival., Results: The mean duration of IMV was significantly reduced in the H-NPPV group compared with the IMV group (P<.0001), without significant difference in duration of weaning (P=.26) and total ventilatory support (P=.45). In the H-NPPV group, the incidence of major complications was less than the IMV group (P=.032). Compared with the H-NPPV group, the IMV group was associated with a greater incidence of VAP (P=.018) and an increased risk of nosocomial pneumonia (P=.049). The mortality rate was similar between the groups, with no significant difference in overall intensive care unit (P=.47) or hospital length of stay (P=.37)., Conclusions: H-NPPV was well tolerated and effective in patients who were difficult to wean., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Purpose: Expiratory asynchrony during pressure support ventilation (PSV) has been recognized as a cause of patient discomfort, increased workload, and impaired weaning process. We evaluated breathing pattern, patient comfort, and patient effort during PSV comparing 2 flow termination criteria: fixed at 5% of peak inspiratory flow vs automatic, real-time, breath-by-breath adjustment within the range of 5% to 55%., Materials and Methods: Randomized crossover clinical trial. Sixteen awake patients, in the process of weaning, under PSV for more than 24 hours were subjected to 3 phases of PSV, each lasting 1 hour and using 1 of the 2 aforementioned termination criteria., Results: Effective pressure support during automatic adjustment (AA) was 12.5±3.2 cm H2O vs 12.5±3.9 cm H2O (P=.9) with the fixed termination criterion, and external positive end-expiratory pressure was 6.2±1.8 vs 6.8±2 (P<.05). The effective termination criterion was higher during AA (31% [23-39] vs 12% [6-23]; P<.01), but without producing premature breath terminations. Pressure overshoots and alternative cycling-off were also decreased. Throughout the AA period, we observed a higher respiratory rate (24±8 breaths/min vs 19±6 breaths/min; P<.001), lower tidal volume (484 ± 88 mL vs 518±102 mL; P<.001), and shorter inspiratory times (1.0±0.3 seconds vs 1.3±0.3 seconds; P<.001). Automatic adjustment was associated with lower airway occlusion pressure after 0.1 second (P0.1) (1.8±0.9 cm H2O vs 2.4±1 cm H2O; P<.01), lower pressure-time product to trigger the ventilator, and lower subjective discomfort (visual analog scale, 3.7±1.3 vs 4.5±1.2; P<.001)., Conclusions: When compared with a fixed termination criterion, the use of a variable, real-time-adjusted termination criterion improved some indices of patient-ventilator synchrony, producing better breathing pattern, less discomfort, and slightly lower patient effort during PSV., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Purpose: Ventilator weaning protocols can improve clinical outcomes, but their impact may vary depending on intensive care unit (ICU) structure, staffing, and acceptability by ICU physicians. This study was undertaken to examine their relationship., Design/methods: We prospectively examined outcomes of 102 mechanically ventilated patients for more than 24 hours and weaned using nurse-driven protocol-directed approach (nurse-driven group) in an intensivist-led ICU with low respiratory therapist staffing and compared them with a historic control of 100 patients who received conventional physician-driven weaning (physician-driven group). We administered a survey to assess ICU physicians' attitude., Results: Median durations of mechanical ventilation (MV) in the nurse-driven and physician-driven groups were 2 and 4 days, respectively (P = .001). Median durations of ICU length of stay (LOS) in the nurse-driven and physician-driven groups were 5 and 7 days, respectively (P = .01). Time of extubation was 2 hours and 13 minutes earlier in the nurse-driven group (P < .001). There was no difference in hospital LOS, hospital mortality, rates of ventilator-associated pneumonia, or reintubation rates between the 2 groups. We identified 4 independent predictors of weaning duration: nurse-driven weaning, Acute Physiology and Chronic Health Evaluation II score, vasoactive medications use, and blood transfusion. Intensive care unit physicians viewed this protocol implementation positively (mean scores, 1.59-1.87 on a 5-point Likert scale)., Conclusions: A protocol for liberation from MV driven by ICU nurses decreased the duration of MV and ICU LOS in mechanically ventilated patients for more than 24 hours without adverse effects and was well accepted by ICU physicians., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Weaning from mechanical ventilation is usually straightforward but is occasionally challenging. Sedation must be used at the appropriate times and with appropriate dosing. A protocol that calls for a daily sedation holiday with a spontaneous breathing trial decreases time on the ventilator. Early tracheostomy is beneficial in traumatic brain injury patients. Noninvasive ventilation is most useful in patients with baseline obstructive sleep apnea and chronic obstructive pulmonary disease., (Copyright © 2012. Published by Elsevier Inc.)

Purpose: The primary objective of this clinical trial of patients on mechanical ventilation was to determine if a weaning protocol implemented solely by nurses could reduce the weaning time relative to usual care (UC)., Materials and Methods: This study is a prospective, randomized, controlled trial conducted from January 2007 to January 2009 that compared protocol-based weaning (PBW) with UC. A total of 122 patients who received invasive ventilation in the medical ICU of the Asan Medical Center were examined. Nurses operated the mechanical ventilators according to a predesigned ventilator-weaning protocol for the PBW group (n = 61), and intensive care unit (ICU) physicians managed weaning in the UC group (n = 61)., Results: There were no significant differences in the 2 groups at baseline. The number of patients who successfully discontinued mechanical ventilation was similar in the 2 groups (PBW, 46 patients, 75.4%; UC, 47 patients, 77.0%; P = .832). The weaning time was 47 hours (interquartile range, 24-168 hours) in the UC group and 25 hours (interquartile range, 5.75-134 hours) in the PBW group (P = .010)., Conclusions: The weaning protocol administered by the nurses was safe and reduced the weaning time from mechanical ventilation in patients who were recovering from respiratory failure., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Purpose: The purpose of this study was to evaluate prediction factors for extubation failure (need for reintubation within 48 hours) in medical intensive care unit patients., Materials and Methods: Sixty-one patients extubated after mechanical ventilation for more than 48 hours were included in the study. A retrospective analysis of medical records and a prospectively maintained database on respiratory parameters was conducted., Results: Low serum anion gap (P = .001), low serum anion gap corrected for serum albumin (P = .010), and low arterial partial pressure of oxygen (Pao(2))/fraction of inspired oxygen (Fio(2)) ratio (P = .032) were significantly associated with extubation failure. Binary logistic regression analysis revealed low uncorrected and corrected serum anion gap (P = .006 and P = .025, respectively; odds ratio, 0.59 for both) and low Pao(2)/Fio(2) ratio (P = .038; odds ratio, 0.99) as risk factors for extubation failure. Regarding extubation failure, receiver operating characteristic curve (ROC) analysis demonstrated good predictive capabilities of serum anion gap (ROC area under the curve, 0.835; P = .004; cutoff, 7.7 mEq/L; sensitivity, 70.4%; specificity, 85.7%) and corrected serum anion gap (ROC area under the curve, 0.808; P = .009; cutoff, 8.8 mEq/L; sensitivity, 87.5%; specificity, 71.4%). A significantly higher risk for extubation failure was observed in patients with serum anion gap 5.2 mEq/L or less (relative risk, 8.8; 95% confidence interval, 2.4-32.4; P = .004) and corrected serum anion gap 8.6 mEq/L or less (relative risk, 10.0; 95% confidence interval, 2.2-44.9; P = .004)., Conclusions: Low preextubation serum anion gap values and low preextubation Pao(2)/Fio(2) ratio might help to predict extubation failure in medical intensive care unit patients., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Purpose: Rapid shallow breathing index (RSBI) is conveniently measured through the ventilator. If continuous positive airway pressure (CPAP) is used, it may change the RSBI value. We measured the RSBI with a handheld spirometer and through the ventilator, with and without CPAP, to assess differences., Materials and Methods: Rapid shallow breathing index was measured in 3 ways: (1) CPAP 0 cm H(2)O and fraction of inspired oxygen (Fio(2)) 0.4, (2) CPAP 5 cm H(2)O and Fio(2) 0.4, and (3) ventilator disconnected and Fio(2) 0.21. Tidal volume and respiratory frequency were recorded from ventilator monitor values in methods 1 and 2, and from a handheld spirometer and observed respiratory frequency, in method 3., Results: A total of 170 measurements, each using all 3 methods, were obtained from 80 patients admitted to a medical intensive care unit. The mean RSBI values for methods 1, 2, and 3 were 98.1 ± 58.7, 87.6 ± 51.2, and 108.3 ± 65.3, respectively (P < .001). The RSBI decreased by 9.4% when using CPAP 0 cm H(2)O and by 19.1% when using CPAP 5 cm H(2)O., Conclusions: The RSBI values measured through the ventilator with CPAP 5 cm H(2)O are much lower than the values measured with a handheld spirometer. Even the RSBI values measured with CPAP 0 cm H(2)O are significantly lower. This is attributable to the base flow delivered by some ventilators. The difference must be taken into account during weaning assessment., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Neurosurgical patients commonly require mechanical ventilation and monitoring in a neurocritical care unit. There are only few studies that specifically address the process of liberation from mechanical ventilation in this population. Patients who remain ventilator or artificial airway dependent receive a tracheostomy. The appropriate timing for the procedure is not well defined and may be different among an inhomogeneous population of critically ill patients. In this article, we review the general principles of liberation and the current literature as it pertains to neurosurgical patients with primary brain injury. The criteria for "readiness of extubation" include a combination of neurologic assessment, hemodynamic, and respiratory parameters. Future studies are required to better assess indicators for extubation readiness, evaluate the predictors of extubation failure in brain-injured patients, and define the most appropriate timing for a tracheostomy., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Purpose: To compare the short-term hemodynamic effects of levosimendan and dobutamine in chronic obstructive pulmonary disease (COPD) patients experiencing weaning difficulties in relation with increased left ventricular filling pressure., Materials and Methods: This prospective, sequential, pilot study included 10 COPD patients experiencing weaning difficulties in relation with increased left ventricular filling pressure ascertained by an increase >10 mm Hg of pulmonary artery occlusion pressure (PAOP) at the shift from mechanical to spontaneous breathing (SB). Patients received 1 h infusion of 7 μg/kg per minute of dobutamine, followed by 24-hour infusion of 0.2 μg/kg per minute levosimendan. Hemodynamic variables were measured under MV and 15 to 30 minutes after SB at baseline, at the end of dobutamine infusion, at a washout period, and after levosimendan infusion., Results: At baseline, the shift from mechanical ventilation to spontaneous ventilation was associated with a significant increase in PAOP from a median of 15 (interquartile range [IQR], 6) to 29 (9) mm Hg. Both drugs reduced significantly the level of PAOP increase at SB, but levosimendan had a greater effect than dobutamine [median PAOP increase (IQR): 5 (2) vs 9 (4) mm Hg, respectively; P < .01]., Conclusions: Both drugs reduced the magnitude of PAOP increase at SB in difficult-to-wean COPD patients. PAOP increase was reduced to a greater extent by levosimendan., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: The objectives of this study were to compare patients' energy expenditure (EE) during pressure support (PS) and T-tube (TT) weaning from mechanical ventilation (MV) through indirect calorimetry (IC) and to crosscheck these findings with the results calculated using Harris-Benedict (HB) equation., Methods: This study is a randomized crossover controlled trial. Patients with clinical criteria for weaning from MV were randomized to PS-TT or TT-PS, with EE measurement for 20 minutes in PS and TT through IC. Energy expenditure was estimated through HB equation with and without activity factor. Statistical analysis used the Student t test for paired samples and Pearson correlation coefficient, as well as Bland-Altman method., Results: Forty patients were included. The mean age and Acute Physiology and Chronic Health Evaluation II score were 56 ± 16 years and 23 ± 8, respectively, with predominance of male patients (70%). Mean EE of patients in TT (1782 ± 375 kcal/d) was 14.4% higher than in PS (1558 ± 304 kcal/d; P < .001). In relation to the EE obtained with the HB equation, the mean (SD) value calculated was 1455 (210) kcal/d, and when considering the activity factor, it was 1609 (236) kcal/d, all of them presenting correlation with the values from IC in PS (r = 0.647) and TT (r = 0.539). However, the limits of agreement between the measured EE and the estimated EE suggest that the HB equation tends to underestimate the EE., Conclusion: Comparison of EE in PS and in TT through IC demonstrated that there is increased EE in the TT mode. The results suggest that the HB equation underestimates the EE of patients in weaning from MV., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Objective(s): Partial pressure of carbon dioxide and oxygen were transcutaneously measured in adults after off-pump coronary artery bypass (OPCAB) surgery. The clinical use of such measurements and interchangeability with arterial blood gas measurements for weaning patients from postoperative mechanical ventilation were assessed., Design: This was a prospective observational study., Setting: Tertiary referral heart hospital., Participants: Postoperative OPCAB surgical patients., Interventions: Transcutaneous oxygen and carbon dioxide measurements., Measurements and Main Results: In this prospective observational study, 32 consecutive adult patients in a tertiary care medical center underwent OPCAB surgery. Noninvasive measurement of respiratory gases was performed during the postoperative period and compared with arterial blood gases. The investigator was blinded to the reports of arterial blood gas studies and weaned patients using a "weaning protocol" based on transcutaneous gas measurement. The number of patients successfully weaned based on transcutaneous measurements and the number of times the weaning process was held up were noted. A total of 212 samples (pairs of arterial and transcutaneous values of oxygen and carbon dioxide) were obtained from 32 patients. Bland-Altman plots and mountain plots were used to analyze the interchangeability of the data. Twenty-five (79%) of the patients were weaned from the ventilator based on transcutaneous gas measurements alone. Transcutaneous carbon dioxide measurements were found to be interchangeable with arterial carbon dioxide during 96% of measurements, versus 79% for oxygen measurements., Conclusion: More than three fourths of the patients were weaned from mechanical ventilation and extubated based on transcutaneous gas values alone after OPCAB surgery. The noninvasive transcutaneous carbon dioxide measurement can be used as a surrogate for arterial carbon dioxide measurement to manage postoperative OPCAB patients., (Copyright 2010 Elsevier Inc. All rights reserved.)

Discontinuation of mechanical ventilation in critically ill patients is a challenging task and involves a careful weighting of the benefits of early extubation and the risks of premature spontaneous breathing trial. Recently, apart from studying different physiological variables by means of descriptive statistical tests, breathing pattern variability analysis has been performed for the assessment of weaning readiness. A limited number of clinical studies implementing different weaning protocols in heterogeneous groups of patients and using a variable set of signal processing techniques have appeared in the critical care literature, with varying results. The purpose of this review article is 3-fold: (1) to describe the different signal processing techniques being implemented for the assessment of weaning readiness, (2) to provide insight into the pathophysiological mechanisms that may govern breath-to-breath variability/complexity in health and disease, and (3) to present results from the critical care literature derived from the application of biosignal analysis tools for the identification of possible weaning indices., (Copyright 2010 Elsevier Inc. All rights reserved.)

Objective: The aim of this study was to evaluate the work of breathing (WOB) behavior during a 120-minute successful spontaneous breathing trial (SBT) with T-tube trial, and its predictive value for extubation outcome., Design: A prospective cohort study., Setting: 2 medical-surgical intensive care units., Patients: Fifty-one consecutive patients mechanically ventilated for more than 48 hours after a successful SBT were extubated based on the institutional protocol and followed for the occurrence of postextubation respiratory distress during 48 hours., Measurements and Main Results: All cases were serially monitored during 120 minutes of SBT using the respiratory monitoring system Ventrak 1500 (Medical Novametrix Systems, Wallingford, CT). Successful extubation occurred in 38 (74.5%) of 51 of the sample. Respiratory and hemodynamic parameters, APACHE II score, sex, days on mechanical ventilation, and cause of respiratory failure were unable to predict extubation outcome. The WOB significantly increased during SBT in extubation failure patients (WOB at 1st minute 0.24 +/- 0.06 J/L vs WOB at 120th minute = 0.39 +/- 0.07 J/L; P < .01) when compared to successfully extubated patients (WOB at 1st minute 0.21 +/- 0.08 J/L vs WOB at 120th minute = 0.24 +/- 0.11 J/L; P = .12). The WOB variation was able to predict extubation outcome only after the 90th minute of SBT (extubation failure = 0.35 +/- 0.08 J/L vs extubation success = 0.22 +/- 0.11 J/L; P = .01)., Conclusion: An increase in the WOB could predict extubation failure during a T-tube trial of 120 minutes.

Objective: To evaluate is serial measurements of respiratory rate (frequency to tidal volume, f/VT) may predict extubation failure (EF) from mechanical ventilation in patients following a successful spontaneous breathing trial (SBT) with first measurement of f/V(T) < or = 105., Design: Prospective cohort study., Setting: Two medical-surgical intensive care units., Patients: Seventy-three patients ventilated for more than 48 hours after successful SBT were extubated and followed up for postextubation respiratory distress during 48 hours., Results: Extubation failure occurred in 16 (21.9%) of 73 patients. Factors such as age, sex, Apache II score, days on mechanical ventilation, respiratory failure cause, and hemodynamic or ventilatory parameters did not predict EF. Patients were evaluated during 120 minutes of SBT, and f/V(T) was measured at the 1st minute (f/V(T-1)), 30th minute (f/V(T-30)), and 120th minute (f/V(T-120)). The f/V(T-30) increased as compared with f/V(T-1) (79 +/- 24 vs 68 +/- 30, P = .01) but did not differ from f/V(T-120) (79 +/- 44 vs 81 +/- 42, P = .79). The f/V(T-1) was lower in successful extubation (ES) as compared with EF patients (62 +/- 29 vs 82 +/- 15, P = .01), and this difference was unchanged during the trial (f/V(T-30): ES [63 +/- 22] vs EF [85 +/- 24], P = .02; and f/V(T-120): ES [65 +/- 26] vs EF [88 +/- 20], P = .01)]., Conclusions: Serial f/V(T) measurements during 120 minutes of SBT were unable to detect EF in patients following a successful SBT with initial f/V(T) lower than 105.

Ventilator-dependent patients with tetraplegia rarely use noninvasive positive-pressure ventilation (NPPV) for long-term ventilation. We report 2 patients with high-level traumatic tetraplegia who were able to return home after being changed from traditional ventilation to NPPV. When they were referred to our hospital from acute care hospitals 2 to 6 months after injury, both were on tracheostomy ventilation with a cuff inflated 24 hours a day, and tidal volume (Vt) settings were low. In case 1, a man with complete C1 tetraplegia was admitted to our hospital 6 months after injury. We changed ventilator settings to high Vt and introduced NPPV. He was discharged home with NPPV with a volume-setting ventilator. Case 2 involved a man in his late twenties with complete C1 tetraplegia who was discharged home with NPPV. After discharge, he trained in glossopharyngeal breathing by himself, enabling him to breathe up to 1900mL of maximum insufflation capacity. Both have lived nearly 1 year without pulmonary complications in the community. They use visiting nurses 3 times a week and services of visiting caregivers. Further study is needed to determine the usefulness of NPPV for long-term ventilatory management.