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.

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.

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.

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.

[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.

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.

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.

Application of heart-rate variability in patients undergoing weaning from mechanical ventilation.

INTRODUCTION: The process of weaning may impose cardiopulmonary stress on ventilated patients. Heart-rate variability (HRV), a noninvasive tool to characterize autonomic function and cardiorespiratory interaction, may be a promising modality to assess patient capability during the weaning process. We aimed to evaluate the association between HRV change and weaning outcomes in critically ill patients. METHODS: This study included 101 consecutive patients recovering from acute respiratory failure. Frequency-domain analysis, including very low frequency, low frequency, high frequency, and total power of HRV was assessed during a 1-hour spontaneous breathing trial (SBT) through a T-piece and after extubation after successful SBT. RESULTS: Of 101 patients, 24 (24%) had SBT failure, and HRV analysis in these patients showed a significant decrease in total power (P = 0.003); 77 patients passed SBT and were extubated, but 13 (17%) of them required reintubation within 72 hours. In successfully extubated patients, very low frequency and total power from SBT to postextubation significantly increased (P = 0.003 and P = 0.004, respectively). Instead, patients with extubation failure were unable to increase HRV after extubation. CONCLUSIONS: HRV responses differ between patients with different weaning outcomes. Measuring HRV change during the weaning process may help clinicians to predict weaning results and, in the end, to improve patient care and outcome.

Noninvasive ventilation immediately after extubation improves weaning outcome after acute respiratory failure: a randomized controlled trial.

INTRODUCTION: Noninvasive ventilation (NIV), as a weaning-facilitating strategy in predominantly chronic obstructive pulmonary disease (COPD) mechanically ventilated patients, is associated with reduced ventilator-associated pneumonia, total duration of mechanical ventilation, length of intensive care unit (ICU) and hospital stay, and mortality. However, this benefit after planned extubation in patients with acute respiratory failure of various etiologies remains to be elucidated. The aim of this study was to determine the efficacy of NIV applied immediately after planned extubation in contrast to oxygen mask (OM) in patients with acute respiratory failure (ARF). METHODS: A randomized, prospective, controlled, unblinded clinical study in a single center of a 24-bed adult general ICU in a university hospital was carried out in a 12-month period. Included patients met extubation criteria with at least 72 hours of mechanical ventilation due to acute respiratory failure, after following the ICU weaning protocol. Patients were randomized immediately before elective extubation, being randomly allocated to one of the study groups: NIV or OM. We compared both groups regarding gas exchange 15 minutes, 2 hours, and 24 hours after extubation, reintubation rate after 48 hours, duration of mechanical ventilation, ICU length of stay, and hospital mortality. RESULTS: Forty patients were randomized to receive NIV (20 patients) or OM (20 patients) after the following extubation criteria were met: pressure support (PSV) of 7 cm H2O, positive end-expiratory pressure (PEEP) of 5 cm H2O, oxygen inspiratory fraction (FiO2)≤40%, arterial oxygen saturation (SaO2)≥90%, and ratio of respiratory rate and tidal volume in liters (f/TV)<105. Comparing the 20 patients (NIV) with the 18 patients (OM) that finished the study 48 hours after extubation, the rate of reintubation in NIV group was 5% and 39% in OM group (P=0.016). Relative risk for reintubation was 0.13 (CI=0.017 to 0.946). Absolute risk reduction for reintubation showed a decrease of 33.9%, and analysis of the number needed to treat was three. No difference was found in the length of ICU stay (P=0.681). Hospital mortality was zero in NIV group and 22.2% in OM group (P=0.041). CONCLUSIONS: In this study population, NIV prevented 48 hours reintubation if applied immediately after elective extubation in patients with more than 3 days of ARF when compared with the OM group. TRIAL REGISTRATION NUMBER ISRCTN: 41524441.

Post-extubation dysphagia is associated with longer hospitalization in survivors of critical illness with neurologic impairment.

INTRODUCTION: Critically ill patients can develop acute respiratory failure requiring endotracheal intubation. Swallowing dysfunction after liberation from mechanical ventilation, also known as post-extubation dysphagia, is common and deleterious among patients without neurologic disease. However, the risk factors associated with the development of post-extubation dysphagia and its effect on hospital lengthofstay in critically ill patients with neurologic disorders remains relatively unexplored. METHODS: We conducted a retrospective, observational cohort study from 2008 to 2010 of patients with neurologic impairment who required mechanical ventilation and subsequently received a bedside swallow evaluation (BSE) by a speech-language pathologist. RESULTS: A BSE was performed after mechanical ventilation in 25% (630/2,484) of all patients. In the 184 patients with neurologic impairment, post-extubation dysphagia was present in 93% (171/184), and was classified as mild, moderate, or severe in 34% (62/184), 26% (48/184), and 33% (61/184), respectively. In univariate analyses, statistically significant risk factors for moderate/severe dysphagia included longer durations of mechanical ventilation and the presence of a tracheostomy. In multivariate analysis, adjusting for age, tracheostomy, cerebrovascular disease, and severity of illness, mechanical ventilation for >7 days remained independently associated with moderate/severe dysphagia (adjusted odds ratio=4.48 (95%confidence interval=2.14 to 9.81), P<0.01). The presence of moderate/severe dysphagia was also significantly associated with prolonged hospital lengthofstay, discharge status, and surgical placement of feeding tubes. When adjusting for age, severity of illness, and tracheostomy, patients with moderate/severe dysphagia stayed in the hospital 4.32 days longer after their initial BSE than patients with none/mild dysphagia (95% confidence interval=3.04 to 5.60 days, P<0.01). CONCLUSION: In a cohort of critically ill patients with neurologic impairment, longer duration of mechanical ventilation is independently associated with post-extubation dysphagia, and the development of post-extubation dysphagia is independently associated with a longer hospital length of stay after the initial BSE.

Effort-adapted modes of assisted breathing.

PURPOSE OF REVIEW: New developments in mechanical ventilation have focused on increasing the patient's control of the ventilator by implementing information on lung mechanics and respiratory drive. Effort-adapted modes of assisted breathing are presented and their potential advantages are discussed. RECENT FINDINGS: Adaptive support ventilation, proportional assist ventilation with load adjustable gain factors and neurally adjusted ventilatory assist are ventilatory modes that follow the concept of adapting the assist to a defined target, instantaneous changes in respiratory drive or lung mechanics. Improved patient ventilator interaction, sufficient unloading of the respiratory muscles and increased comfort have been recently associated with these ventilator modalities. There are, however, scarce data with regard to outcome improvement, such as length of mechanical ventilation, ICU stay or mortality (commonly accepted targets to demonstrate clinical superiority). SUMMARY: Within recent years, a major step forward in the evolution of assisted (effort-adapted) modes of mechanical ventilation was accomplished. There is growing evidence that supports the physiological concept of closed-loop effort-adapted assisted modes of mechanical ventilation. However, at present, the translation into a clear outcome benefit remains to be proven. In order to fill the knowledge gap that impedes the broader application, larger randomized controlled trials are urgently needed. However, with clearly proven drawbacks of conventional assisted modes such as pressure support ventilation, it is probably about time to leave these modes introduced decades ago behind.

Transthoracic Echocardiography with Doppler Tissue Imaging predicts weaning failure from mechanical ventilation: evolution of the left ventricle relaxation rate during a spontaneous breathing trial is the key factor in weaning outcome.

INTRODUCTION: There is growing evidence to suggest that transthoracic echocardiography (TTE) should be used to identify the cardiac origin of respiratory weaning failure. THE AIMS OF OUR STUDY WERE: first, to evaluate the ability of transthoracic echocardiography, with mitral Doppler inflow E velocity to annular tissue Doppler Ea wave velocity (E/Ea) ratio measurement, to predict weaning failure from mechanical ventilation in patients, including those with atrial fibrillation; and second, to determine whether the depressed left ejection fraction and/or diastolic dysfunction participate in weaning outcome. METHODS: The sample included patients on mechanical ventilation for over 48 hours. A complete echocardiography was performed just before the spontaneous breathing trial (SBT) and 10 minutes after starting the SBT. Systolic dysfunction was defined by a left ventricle ejection fraction under 50% and relaxation impairment by a protodiastolic annulus mitral velocity Ea under or equal to 8 cm/second. RESULTS: A total of 68 patients were included. Twenty failed the weaning process and the other 48 patients succeeded. Before the SBT, the E/Ea ratio was higher in the failed group than in the successful group. The E/Ea measured during the SBT was also higher in the failed group. The cut-off value, obtained from receiver operating characteristics (ROC) curve analysis, to predict weaning failure gave an E/Ea ratio during the SBT of 14.5 with a sensitivity of 75% and a specificity of 95.8%. The left ventricular ejection fraction did not differ between the two groups whereas Ea was lower in the failed group. Ea increased during SBT in the successful group while no change occurred in the failed group. CONCLUSIONS: Measurement of the E/Ea ratio with TTE could predict weaning failure. Diastolic dysfunction with relaxation impairment is strongly associated with weaning failure. Moreover, the impossibility of enhancing the left ventricle relaxation rate during the SBT seems to be the key factor of weaning failure. In contrast, the systolic dysfunction was not associated with weaning outcome.

Outcomes of prolonged mechanic ventilation: a discrimination model based on longitudinal health insurance and death certificate data.

BACKGROUND: This study investigated prognosis among patients under prolonged mechanical ventilation (PMV) through exploring the following issues: (1) post-PMV survival rates, (2) factors associated with survival after PMV, and (3) the number of days alive free of hospital stays requiring mechanical ventilation (MV) care after PMV. METHODS: This is a retrospective cohort study based on secondary analysis of prospectively collected data in the national health insurance system and governmental data on death registry in Taiwan. It used data for a nationally representative sample of 25,482 patients becoming under PMV (> = 21 days) during 1998-2003. We calculated survival rates for the 4 years after PMV, and adopted logistic regression to construct prediction models for 3-month, 6-month, 1-year, and 2-year survival, with data of 1998-2002 for model estimation and the 2003 data for examination of model performance. We estimated the number of days alive free of hospital stays requiring MV care in the immediate 4-year period after PMV, and contrasted patients who had low survival probability with all PMV patients. RESULTS: Among these patients, the 3-month survival rate was 51.4%, and the 1-year survival rate was 31.9%. Common health conditions with significant associations with poor survival included neoplasm, acute and unspecific renal failure, chronic renal failure, non-alcoholic liver disease, shock and septicaemia (odd ratio < 0.7, p < 0.05). During a 4-year follow-up period for patients of year 2003, the mean number of days free of hospital stays requiring MV was 66.0 in those with a predicted 6-month survival rate < 10%, and 111.3 in those with a predicted 2-year survival rate < 10%. In contrast, the mean number of days was 256.9 in the whole sample of patients in 2003. CONCLUSIONS: Neoplasm, acute and unspecific renal failure, shock, chronic renal failure, septicemia, and non-alcoholic liver disease are significantly associated with lower survival among PMV patients. Patients with anticipated death in a near future tend to spend most of the rest of their life staying in hospital using MV services. This calls for further research into assessing PMV care need among patients at different prognosis stages of diseases listed above.

Patient-ventilator interaction: the last 40 years.

Patient-ventilator synchrony is a complex issue affected by ventilator performance, patient characteristics, and the patient-ventilator interface. The history of patient-ventilator interaction includes avoidance of pharmacalogic paralysis, the development of spontaneous breathing systems, microprocessor technology to maximize interaction, and closed-loop control. While most clinicians agree that patient-ventilator synchrony is desirable, there remain no cause-and-effect data that asynchrony is associated with poor outcome.

Adaptive support ventilation with protocolized de-escalation and escalation does not accelerate tracheal extubation of patients after nonfast-track cardiothoracic surgery.

BACKGROUND: It is uncertain whether adaptive support ventilation (ASV) accelerates weaning of nonfast-track cardiothoracic surgery patients. A lower operator set %-minute ventilation with ASV may allow for an earlier definite switch from controlled to assisted ventilation, potentially hastening tracheal extubation. We hypothesized that ASV using protocolized de-escalation and escalation of operator set %-minute ventilation (ASV-DE) reduces time until tracheal extubation compared with ASV using a fixed operator set %-minute ventilation (standard ASV) in uncomplicated patients after nonfast-track coronary artery bypass graft. METHODS: We performed a randomized controlled trial comparing ASV-DE with standard ASV. With ASV-DE, as soon as body temperature was >35.0°C with pH >7.25, operator set %-minute ventilation was decreased stepwise to a minimum of 70%. RESULTS: Sixty-three patients were randomized to ASV-DE, and 63 patients to standard ASV. The duration of mechanical ventilation was not different between groups (10.8 [6.5-16.1] vs 10.7 [6.6-13.9] hours, ASV-DE versus standard ASV; P = 0.32). Time until the first assisted breathing period was shorter (3.1 [2.0-6.7] vs 3.9 [2.1-7.5] hours) and the number of assisted ventilation episodes was higher (78 [34-176] vs 57 [32-116] episodes), but differences did not reach statistical significance. The duration of assisted ventilation episodes that ended with tracheal extubation was different between groups (2.5 [0.9-4.6] vs 1.4 [0.3-3.5] hours, ASV-DE versus standard ASV; P < 0.05). CONCLUSION: Compared with standard ASV, weaning of patients after nonfast-track coronary artery bypass graft using ASV with protocolized de-escalation and escalation does not shorten time to tracheal extubation.

Weaning critically ill adults from invasive mechanical ventilation: a national survey.

PURPOSE: To determine the stated practices of clinicians in weaning critically ill adults from invasive ventilation. METHODS: We conducted a cross-sectional, self-administered postal survey of Critical Care physicians and respiratory therapists (RTs) in leadership roles at Canadian teaching hospitals. We identified respondents using electronic mail and telephone correspondence. We used rigorous survey methodology to develop, test, and administer the questionnaire. RESULTS: One hundred ten of 162 (67.9%) clinicians returned the survey with 99 respondents (55 physicians and 44 RTs) completing it either in-part or in-full. Approximately 95% of respondents acknowledged ever performing spontaneous breathing trials (SBTs) in clinical practice. Of these, 95.6% and 32% of respondents reported conducting daily and twice-daily screening to identify SBT candidates, at least sometimes. The three most common techniques to conduct SBTs included; pressure support (PS) with positive end-expiratory pressure (70.8%), continuous positive airway pressure (35.7%), and use of a T-piece (25.0%). PS ventilation was the weaning strategy used most frequently before SBTs. Most respondents (57.1%) considered continuous infusion of sedative-hypnotics to be a relative contraindication to tracheal extubation. However, concurrent administration of low dose vasopressors, inotropes, and analgesic boluses, or continuous analgesic infusions were considered acceptable amongst 60.8%, 73.2%, 78.4% and 58.8% of respondents, respectively. We did not observe regional variation in whether clinicians ever perform SBTs, the ventilatory modes used prior to an SBT nor in the use of PS and SBTs during the weaning process. CONCLUSIONS: Pressure support and SBTs are common features of weaning in Canadian teaching hospitals. Compared to the published literature, our survey suggests that weaning practices have evolved over time and that practice variation may be greater on an international level compared to a national level.