Evolution Over Time of Ventilatory Management and Outcome of Patients With Neurologic Disease.

OBJECTIVES: To describe the changes in ventilator management over time in patients with neurologic disease at ICU admission and to estimate factors associated with 28-day hospital mortality. DESIGN: Secondary analysis of three prospective, observational, multicenter studies. SETTING: Cohort studies conducted in 2004, 2010, and 2016. PATIENTS: Adult patients who received mechanical ventilation for more than 12 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among the 20,929 patients enrolled, we included 4,152 (20%) mechanically ventilated patients due to different neurologic diseases. Hemorrhagic stroke and brain trauma were the most common pathologies associated with the need for mechanical ventilation. Although volume-cycled ventilation remained the preferred ventilation mode, there was a significant (p < 0.001) increment in the use of pressure support ventilation. The proportion of patients receiving a protective lung ventilation strategy was increased over time: 47% in 2004, 63% in 2010, and 65% in 2016 (p < 0.001), as well as the duration of protective ventilation strategies: 406 days per 1,000 mechanical ventilation days in 2004, 523 days per 1,000 mechanical ventilation days in 2010, and 585 days per 1,000 mechanical ventilation days in 2016 (p < 0.001). There were no differences in the length of stay in the ICU, mortality in the ICU, and mortality in hospital from 2004 to 2016. Independent risk factors for 28-day mortality were age greater than 75 years, Simplified Acute Physiology Score II greater than 50, the occurrence of organ dysfunction within first 48 hours after brain injury, and specific neurologic diseases such as hemorrhagic stroke, ischemic stroke, and brain trauma. CONCLUSIONS: More lung-protective ventilatory strategies have been implemented over years in neurologic patients with no effect on pulmonary complications or on survival. We found several prognostic factors on mortality such as advanced age, the severity of the disease, organ dysfunctions, and the etiology of neurologic disease.

Respective contribution of intensive care unit-acquired limb muscle and severe diaphragm weakness on weaning outcome and mortality: a post hoc analysis of two cohorts.

BACKGROUND: Intensive care unit (ICU)-acquired weakness (ICU-AW) and ICU-acquired diaphragm dysfunction (ICU-DD) occur frequently in mechanically ventilated (MV) patients. It is unknown whether they have different risk factors and different impacts on outcome. This study was designed to (1) describe the respective risk factors associated with ICU-AW and severe ICU-DD and (2) evaluate the respective impact of ICU-AW and severe ICU-DD on outcome. METHODS: Post hoc analysis of two prospective cohort studies conducted in two ICUs. In patients mechanically ventilated for at least 24 h undergoing a first spontaneous breathing trial, severe ICU-DD was defined as diaphragm twitch pressure < 7 cmH2O and ICU-AW was defined as Medical Research Council Score < 48. RESULTS: One hundred sixteen patients were assessed. Factors independently associated with severe ICU-DD were age, longer duration of MV, and exposure to sufentanil, and those factors associated with ICU-AW were longer duration of MV and exposure to norepinephrine. Severe ICU-DD (OR 3.56, p = 0.008), but not ICU-AW, was independently associated with weaning failure (59%). ICU-AW (OR 4.30, p = 0.033), but not severe ICU-DD, was associated with ICU mortality. Weaning failure and mortality rate were higher in patients with both severe ICU-DD and ICU-AW (86% and 39%, respectively) than in patients with either severe ICU-DD (64% and 0%) or ICU-AW (63% and 13%). CONCLUSION: Severe ICU-DD and ICU-AW have different risk factors and different impacts on weaning failure and mortality. The impact of the combination of ICU-DD and ICU-AW is more pronounced than their individual impact.

Effects of levosimendan on respiratory muscle function in patients weaning from mechanical ventilation.

PURPOSE: Respiratory muscle weakness frequently develops in critically ill patients and is associated with adverse outcome, including difficult weaning from mechanical ventilation. Today, no drug is approved to improve respiratory muscle function in these patients. Previously, we have shown that the calcium sensitizer levosimendan improves calcium sensitivity of human diaphragm muscle fibers in vitro and contractile efficiency of the diaphragm in healthy subjects. The main purpose of this study is to investigate the effects of levosimendan on diaphragm contractile efficiency in mechanically ventilated patients. METHODS: In a double-blind randomized placebo-controlled trial, mechanically ventilated patients performed two 30-min continuous positive airway pressure (CPAP) trials with 5-h interval. After the first CPAP trial, study medication (levosimendan 0.2 µg/kg/min continuous infusion or placebo) was administered. During the CPAP trials, electrical activity of the diaphragm (EAdi), transdiaphragmatic pressure (Pdi), and flow were measured. Neuromechanical efficiency (primary outcome parameter) was calculated. RESULTS: Thirty-nine patients were included in the study. Neuromechanical efficiency was not different during the CPAP trial after levosimendan administration compared to the CPAP trial before study medication. Tidal volume and minute ventilation were higher after levosimendan administration (11 and 21%, respectively), whereas EAdi and Pdi were higher in both groups in the CPAP trial after study medication compared to the CPAP trial before study medication. CONCLUSIONS: Levosimendan does not improve diaphragm contractile efficiency.

Improvement in Successful Extubation in Newborns After a Protocol-driven Approach: A Quality Improvement Initiative.

OBJECTIVE: To reduce extubation failure rate by implementing protocol-driven ventilation and extubation strategies. METHODS: Quality improvement project in a level II neonatal care unit from April 2017 to January 2018. Ventilation and extubation protocols implemented from 1 August, 2017. 18 ventilated newborns in the pre-protocol period, 16 in Plan-do-check-act (PDCA) cycle I and 17 in PDCA cycle II. Primary outcome was extubation failure within the first 72 h of extubation. RESULTS: Extubation failure rate reduced from 41.7% (pre-protocol period) to 23.8% (PDCA 1 and 2, OR 0.44, 95% CI 0.12 to 1.59, P = 0.21). Median time to first extubation attempt significantly decreased (71.5 h to 38 h, P=0.046). CONCLUSIONS: A protocolized approach through quality improvement initiative demonstrated a sustained improvement in successful extubation with a significant reduction in the median time to first extubation attempt in ventilated newborns.

Decannulation of tracheotomized patients after long-term mechanical ventilation - results of a prospective multicentric study in German neurological early rehabilitation hospitals.

BACKGROUND: In the course of neurological early rehabilitation, decannulation is attempted in tracheotomized patients after weaning due to its considerable prognostic significance. We aimed to identify predictors of a successful tracheostomy decannulation. METHODS: From 09/2014 to 03/2016, 831 tracheotomized and weaned patients (65.4 ± 12.9 years, 68% male) were included consecutively in a prospective multicentric observation study. At admission, sociodemographic and clinical data (e.g. relevant neurological and internistic diseases, duration of mechanical ventilation, tracheotomy technique, and nutrition) as well as functional assessments (Coma Recovery Scale-Revised (CRS-R), Early Rehabilitation Barthel Index, Bogenhausener Dysphagia Score) were collected. Complications and the success of the decannulation procedure were documented at discharge. RESULTS: Four hundred seventy patients (57%) were decannulated. The probability of decannulation was significantly negatively associated with increasing age (OR 0.68 per SD = 12.9 years, p < 0.001), prolonged duration of mechanical ventilation (OR 0.57 per 33.2 days, p < 0.001) and complications. An oral diet (OR 3.80; p < 0.001) and a higher alertness at admission (OR 3.07 per 7.18 CRS-R points; p < 0.001) were positively associated. CONCLUSIONS: This study identified practically measurable predictors of decannulation, which in the future can be used for a decannulation prognosis and supply optimization at admission in the neurological early rehabilitation clinic.

A Multidisciplinary Protocol-Driven Approach to Improve Extubation Times After Cardiac Surgery.

BACKGROUND: Prolonged intubation after cardiac surgery is associated with significant morbidity. A fast-track extubation protocol primarily driven by bedside providers was instituted for all postoperative cardiac surgery patients to facilitate safe and expeditious extubation. METHODS: A retrospective review of 1,581 cardiac surgery patients over an 8-year period was performed. Before 2011, nonprotocolized standard perioperative management was utilized (n = 807). From 2011 onward, a fast-track extubation (FTE) protocol directed by bedside providers was instituted (n = 774). Postoperatively, patients were placed on pressure-regulated volume control and titrated down to minimal support to maintain peripheral capillary oxygen saturation greater than 94%. For patients deemed ready for weaning (no evidence of hypoxia, hemodynamic instability, and so forth), a 30-minute continuous positive airway pressure trial was performed. Patients meeting all neurologic, respiratory, and cardiovascular criteria were extubated. The impact of the FTE algorithm on timely extubation, clinical outcomes, and safety was assessed. RESULTS: Baseline preoperative and intraoperative characteristics were similar between pre-FTE and FTE groups. Before instituting the FTE protocol, the rate of early extubation (less than 6 hours) was 43.7%, and increased to 64.1% during the FTE era (p < 0.001). Median time to extubation was also found to be significantly decreased: 295 minutes (interquartile range: 288) versus 385 minutes (interquartile range: 362, p = 0.041). There was no statistically significant difference in reintubation rates or 30-day mortality. CONCLUSIONS: The institution of a bedside provider-directed FTE pathway reduced overall intubation times and increased the rate of early extubation, without an increase in reintubation or mortality. This program-wide multidisciplinary approach appears to promote safe and expeditious extubation of cardiac surgery patients.

International Practice Variation in Weaning Critically Ill Adults from Invasive Mechanical Ventilation.

RATIONALE: Randomized trials and meta-analyses have informed several aspects of weaning. Results are rarely replicated in practice, as evidence is applied in intensive care units that differ from the settings in which it was generated. OBJECTIVES: We aimed to: 1) describe weaning practice variation (identifying weaning candidates, conducting spontaneous breathing trials, using ventilator modes, and other aspects of care during weaning); 2) characterize regional differences in weaning practices; and 3) identify factors associated with practice variation. METHODS: We conducted a cross-sectional, self-administered, international postal survey of adult intensivist members of regional critical care societies from six geographic regions, including Canada, India, the United Kingdom, Europe, Australia/New Zealand, and the United States. We worked with societies to randomly select potential respondents from membership lists and administer questionnaires with the goal of obtaining 200 responses per region. RESULTS: We analyzed 1,144 questionnaires (Canada, 156; India, 136; United Kingdom, 219; Europe, 260; Australia/New Zealand, 196; United States, 177). Across regions, most respondents screened patients once daily to identify spontaneous breathing trials candidates (regional range, 70.0%-95.6%) and less often screened twice daily (range, 12.2%-33.1%) or more than twice daily (range, 1.6%-18.2%). To wean patients, most respondents used pressure support alone (range, 31.0%-71.7%) or with spontaneous breathing trials (range, 35.7%-68.1%). To conduct spontaneous breathing trials, respondents predominantly used pressure support with positive end-expiratory pressure (range, 56.5%-72.3%) and T-piece (8.9%-59.5%). Across regions, we found important variation in screening frequency, spontaneous breathing trials techniques; ventilator modes, written directives to guide care, noninvasive ventilation; and the roles played by available personnel in various aspects of weaning. CONCLUSIONS: Our findings document the presence and extent of practice variation in ventilator weaning on an international scale, and highlight the multidisciplinary and collaborative nature of weaning.

Implementation of an Early Extubation Protocol in Cardiac Surgical Patients Decreased Ventilator Time But Not Intensive Care Unit or Hospital Length of Stay.

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.

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.

[Weaning Unit of the University Medicine Greifswald - Institutional Structure and Weaning Results from Prolonged Ventilation over 10 Years]. / Weaningzentrum Greifswald ­ Struktur und Ergebnisse bei der Entwöhnung von der Langzeitbeatmung über zehn Jahre.

The increasing importance of intensive care medicine including mechanical ventilation has been accompanied by the demand of weaning opportunities for patients undergoing prolonged mechanical ventilation. Consequently, specialised clinical institutions, focusing on the weaning from mechanical ventilation, have been established since the 1980 s.The present article illustrates the structural development and results of such a specialised institution at the University Medicine Greifswald, using data of 616 patients collected within the past ten years (2006 - 2015). Across the years, a shift in the underlying disease leading to mechanical ventilation can be found, with rising numbers of patients suffering from pneumonia/sepsis and declining numbers of patients who underwent cardiac surgery in advance. The days with mechanical ventilation outside (p = 0.004) and within the investigated institution (p = 0.02) are significantly declining. The percentage of successfully weaned patients increased from 62.7 % (2006 - 2010) to 77.3 % (2011 - 2015), p < 0.001. Consecutively, the percentage of patients who remained mechanically ventilated decreased from 16.4 % to 9.6 % (p < 0.001) and the share of in-hospital deceased patients significantly declined from 20.9 % to 13.0 % (p < 0.001). Furthermore, the one-year-survival after hospital discharge in successful weaned patients was 72 percent. The present data, collected at the University Medicine Greifswald are quite comparable to data of other German institutions that are specialised on weaning from mechanical ventilation.

2016 Year in Review: Mechanical Ventilation.

The fundamental goals of mechanical ventilation are to improve pulmonary gas exchange and relieve respiratory distress, thus permitting lung and airway healing, while at the same time lessening the risk for iatrogenic complications. This review will summarize some of the advances in mechanical ventilation in 2016, with a particular focus on ventilator-associated clinical challenges and outcomes.

Revolving door respiratory patients: A rehabilitative perspective.

Rehabilitation is an integral component of care for patients affected by either acute or chronic pulmonary diseases. The key elements of rehabilitation treatment for critical respiratory patients are as follows: weaning from mechanical ventilation, respiratory therapy, physical reconditioning, and occupational therapy. It should be noted that patients affected by pulmonary diseases are prone to hospital re-admission due to frequent exacerbations, especially in cases with more severe stages of chronic obstructive pulmonary disease. A periodical worsening of clinical conditions is common in asthma, acute respiratory distress syndrome survivors, obstructive sleep apnea syndrome, and pulmonary fibrosis, as well as in patients with severe neuromuscular diseases. These patients are often identified as "revolving door patients". Pulmonary patients are typically forced to maintain bed rest, or at least spend most of their waking hours dealing with mobility limitations, due to various pathological conditions including dyspnea, fatigue, and poor tolerance of movements. Alterations in mood are common in pulmonary patients who experience a decreased quality of life and limited social interactions. These negative emotional and cognitive aspects can be a major limitation to the provision of care, because to enhance and facilitate a degree of autonomy, the patient must be cooperative and pro-active.

Volumetric capnography: lessons from the past and current clinical applications.

Dead space is an important component of ventilation-perfusion abnormalities. Measurement of dead space has diagnostic, prognostic and therapeutic applications. In the intensive care unit (ICU) dead space measurement can be used to guide therapy for patients with acute respiratory distress syndrome (ARDS); in the emergency department it can guide thrombolytic therapy for pulmonary embolism; in peri-operative patients it can indicate the success of recruitment maneuvers. A newly available technique called volumetric capnography (Vcap) allows measurement of physiological and alveolar dead space on a regular basis at the bedside. We discuss the components of dead space, explain important differences between the Bohr and Enghoff approaches, discuss the clinical significance of arterial to end-tidal CO2 gradient and finally summarize potential clinical indications for Vcap measurements in the emergency room, operating room and ICU.

Venovenous Extracorporeal Membrane Oxygenation in Intractable Pulmonary Insufficiency: Practical Issues and Future Directions.

Venovenous extracorporeal membrane oxygenation (vv-ECMO) is a highly invasive method for organ support that is gaining in popularity due to recent technical advances and its successful application in the recent H1N1 epidemic. Although running a vv-ECMO program is potentially feasible for many hospitals, there are many theoretical concepts and practical issues that merit attention and require expertise. In this review, we focus on indications for vv-ECMO, components of the circuit, and management of patients on vv-ECMO. Concepts regarding oxygenation and decarboxylation and how they can be influenced are discussed. Day-to-day management, weaning, and most frequent complications are covered in light of the recent literature.

Impact of a Palliative Care Program on Tracheostomy Utilization in a Community Hospital.

BACKGROUND: Tracheostomies are typically provided to wean patients off the ventilator. However, in many circumstances tracheostomies are placed in patients who are at the end of their life with little hope of meaningful recovery. Palliative care teams decrease utilization of aggressive medical interventions in patients who are at the end of life. OBJECTIVE: The study objective was to determine the impact of a palliative care team on tracheostomy utilization in a community hospital setting. METHODS: The study was a four-year retrospective analysis of adult patients undergoing elective tracheostomy two years before and after the establishment of a palliative care program. The study in an ethnically diverse community hospital included patients older than 18 years old, with patients undergoing a tracheostomy due to trauma excluded. Before and after comparisons were made of demographics, in-hospital mortality, length of stay, and discharge status of patients undergoing tracheostomy. RESULTS: Seven hundred ninety patients undergoing tracheostomy were identified (n = 406, n = 384 before and after September 10, 2010, respectively). Patients were ethnically diverse (Caucasian 43%, Asian 23%, African American 11%, Hispanic 7%). The number of hospital admissions slightly increased during these two time periods (n = 58,926; n = 60,662, respectively). There were no statistical differences in age (73 versus 72, p = 0.827); gender (n = 218 [54%] versus n = 217 [57%] male, p = 0.426); or race (n = 187 [46%] versus n = 150 [39%] Caucasian, p = 0.073) in the two time periods. Patients who underwent tracheostomy after a palliative care service was established had less incidence of comorbid disease (Charlson Comorbidity Index score [CCIS]: 2 versus 3, p = 0.025); lower inpatient mortality (n = 107 [28%] versus n = 148 [37%], p = 0.009]); greater discharge to home or rehabilitation (n = 262 [68%] versus n = 249 [62%], p = 0.01); and lower rates of palliative weaning from mechanical ventilation (n = 61[16%] versus n = 113 [28%], p < 0.001). CONCLUSIONS: In an ethnically diverse community hospital, the institution of a palliative care program appears to have improved patient selection for tracheostomy with lower rates of inpatient mortality, improved rates of home discharge, and lower rates of palliative weaning from mechanical ventilation.

The implausibility of 'usual care' in an open system: sedation and weaning practices in Paediatric Intensive Care Units (PICUs) in the United Kingdom (UK).

BACKGROUND: The power of the randomised controlled trial depends upon its capacity to operate in a closed system whereby the intervention is the only causal force acting upon the experimental group and absent in the control group, permitting a valid assessment of intervention efficacy. Conversely, clinical arenas are open systems where factors relating to context, resources, interpretation and actions of individuals will affect implementation and effectiveness of interventions. Consequently, the comparator (usual care) can be difficult to define and variable in multi-centre trials. Hence outcomes cannot be understood without considering usual care and factors that may affect implementation and impact on the intervention. METHODS: Using a fieldwork approach, we describe PICU context, 'usual' practice in sedation and weaning from mechanical ventilation, and factors affecting implementation prior to designing a trial involving a sedation and ventilation weaning intervention. We collected data from 23 UK PICUs between June and November 2014 using observation, individual and multi-disciplinary group interviews with staff. RESULTS: Pain and sedation practices were broadly similar in terms of drug usage and assessment tools. Sedation protocols linking assessment to appropriate titration of sedatives and sedation holds were rarely used (9% and 4% of PICUs respectively). Ventilator weaning was primarily a medical-led process with 39% of PICUs engaging senior nurses in the process: weaning protocols were rarely used (9% of PICUs). Weaning methods were variably based on clinician preference. No formal criteria or use of spontaneous breathing trials were used to test weaning readiness. Seventeen PICUs (74%) had prior engagement in multi-centre trials, but limited research nurse availability. Barriers to previous trial implementation were intervention complexity, lack of belief in the evidence and inadequate training. Facilitating factors were senior staff buy-in and dedicated research nurse provision. CONCLUSIONS: We examined and identified contextual and organisational factors that may impact on the implementation of our intervention. We found usual practice relating to sedation, analgesia and ventilator weaning broadly similar, yet distinctively different from our proposed intervention, providing assurance in our ability to evaluate intervention effects. The data will enable us to develop an implementation plan; considering these factors we can more fully understand their impact on study outcomes.

Timing and Strategy for Weaning From Venoarterial ECMO are Complex Issues.

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.

Variability is adaptability also during weaning!

Heart rate variability in the frequency domain can now be obtained at the bedside in the ICU. Promising data suggest that it may help to characterize a patient response to a spontaneous breathing trial. Refinement of the analysis could even help to predict the outcome of extubation or at least help to detect early patients at risk of failure. It is possible that combining this type of analysis, the breathing pattern variability, and other objective indices could help clinicians in the decision-making process of weaning and extubation.

Our paper 20 years later: how has withdrawal from mechanical ventilation changed?

Withdrawal from mechanical ventilation (or weaning) is one of the most common procedures in intensive care units. Almost 20 years ago, we published one of the seminal papers on weaning in which we showed that the best method for withdrawal from mechanical ventilation in difficult-to-wean patients was a once-daily spontaneous breathing trial with a T-piece. Progress has not stood still, and in the intervening years up to the present several other studies, by our group and others, have shaped weaning into an evidence-based technique. The results of these studies have been applied progressively to routine clinical practice. Currently, withdrawal from mechanical ventilation can be summarized as the evaluation of extubation readiness based on the patient's performance during a spontaneous breathing trial. This trial can be performed with a T-piece, which is the most common approach, or with continuous positive airway pressure or low levels of pressure support. Most patients can be disconnected after passing the first spontaneous breathing trial. In patients who fail the first attempt at withdrawal, the use of a once-daily spontaneous breathing trial or a gradual reduction in pressure support are the preferred weaning methods. However, new applications of standard techniques, such as noninvasive positive pressure ventilation, or new methods of mechanical ventilation, such as automatic tube compensation, automated closed-loop systems, and automated knowledge-based weaning systems, can play a role in the management of the patients with difficult or prolonged weaning.