Evidence-based guidelines for weaning and discontinuing ventilatory support: a collective task force facilitated by the American College of Chest Physicians; the American Association for Respiratory Care; and the American College of Critical Care Medicine

Mechanical ventilation weaning protocol improves medical adherence and results

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.

Effects of Physician-targeted Pay for Performance on Use of Spontaneous Breathing Trials in Mechanically Ventilated Patients

RATIONALE

Pay for performance is an increasingly common quality improvement strategy despite the absence of robust supporting evidence.

OBJECTIVES

To determine the impact of a financial incentive program rewarding physicians for the completion of daily spontaneous breathing trials (SBTs) in three academic hospitals.

METHODS

We compared data from mechanically ventilated patients from 6 months before to 2 years after introduction of a financial incentive program that provided annual payments to critical care physicians contingent on unit-level SBT completion rates. We used Poisson regression to compare the frequency of days on which SBTs were completed among eligible patients and days on which patients were excluded from SBT eligibility among all mechanically ventilated patients. We used multivariate regression to compare risk-adjusted duration of mechanical ventilation and in-hospital mortality.

MEASUREMENTS AND MAIN RESULTS

The cohort included 7,291 mechanically ventilated patients with 75,621 ventilator days. Baseline daily SBT rates were 96.8% (hospital A), 16.4% (hospital B), and 74.7% (hospital C). In hospital A, with the best baseline performance, there was no change in SBT rates, exclusion rates, or duration of mechanical ventilation across time periods. In hospitals B and C, with lower SBT completion rates at baseline, there was an increase in daily SBT completion rates and a concomitant increase in exclusions from eligibility. Duration of mechanical ventilation decreased in hospital C but not in hospital B. Mortality was unchanged for all hospitals.

CONCLUSIONS

In hospitals with low baseline SBT completion, physician-targeted financial incentives were associated with increased SBT rates driven in part by increased exclusion rates, without consistent improvements in outcome.

Lung Rest During Extracorporeal Membrane Oxygenation for Neonatal Respiratory Failure-Practice Variations and Outcomes

OBJECTIVE

Describe practice variations in ventilator strategies used for lung rest during extracorporeal membrane oxygenation for respiratory failure in neonates, and assess the potential impact of various lung rest strategies on the duration of extracorporeal membrane oxygenation and the duration of mechanical ventilation after decannulation.

DATA SOURCES

Retrospective cohort analysis from the Extracorporeal Life Support Organization registry database during the years 2008-2013.

STUDY SELECTION

All extracorporeal membrane oxygenation runs for infants less than or equal to 30 days of life for pulmonary reasons were included.

DATA EXTRACTION

Ventilator type and ventilator settings used for lung rest at 24 hours after extracorporeal membrane oxygenation initiation were obtained.

DATA SYNTHESIS

A total of 3,040 cases met inclusion criteria. Conventional mechanical ventilation was used for lung rest in 88% of cases and high frequency ventilation was used in 12%. In the conventional mechanical ventilation group, 32% used positive end-expiratory pressure strategy of 4-6 cm H2O (low), 22% used 7-9 cm H2O (mid), and 43% used 10-12 cm H2O (high). High frequency ventilation was associated with an increased mean (SEM) hours of extracorporeal membrane oxygenation (150.2 [0.05] vs 125 [0.02]; p < 0.001) and an increased mean (SEM) hours of mechanical ventilation after decannulation (135 [0.09] vs 100.2 [0.03]; p = 0.002), compared with conventional mechanical ventilation among survivors. Within the conventional mechanical ventilation group, use of higher positive end-expiratory pressure was associated with a decreased mean (SEM) hours of extracorporeal membrane oxygenation (high vs low: 136 [1.06] vs 156 [1.06], p = 0.001; mid vs low: 141 [1.06] vs 156 [1.06]; p = 0.04) but increased duration of mechanical ventilation after decannulation in the high positive end-expiratory pressure group compared with low positive end-expiratory pressure (p = 0.04) among survivors.

CONCLUSIONS

Wide practice variation exists with regard to ventilator settings used for lung rest during neonatal respiratory extracorporeal membrane oxygenation. Use of high frequency ventilation when compared with conventional mechanical ventilation and use of low positive end-expiratory pressure strategy when compared with mid positive end-expiratory pressure and high positive end-expiratory pressure strategy is associated with longer duration of extracorporeal membrane oxygenation. Further research to provide evidence to drive optimization of pulmonary management during neonatal respiratory extracorporeal membrane oxygenation is warranted.

Weaning attempts, cough strength and albumin are independent risk factors of reintubation in medical patients

BACKGROUND

Reintubation is associated with increased hospital mortality. It is necessary to identify risk factors associated with reintubation.

METHODS

A prospective observational study was performed in a respiratory intensive care unit. Medical patients who successfully completed a spontaneous breathing trial (SBT) were enrolled. Before extubation, age, gender, vital signs, acute physiology and chronic health evaluation II score, SBT attempts, cough peak flow, arterial blood gas tests and albumin were recorded.

RESULTS

We enrolled 139 patients. Of these, 22 (15.8%) patients experienced reintubation within 72 hours after extubation. SBT attempts (odds ratio [OR] = 1.446, 95% confidence interval [CI]: 1.095-1.910), cough peak flow (OR = 0.975, 95% CI: 0.956-0.994) and albumin (OR = 0.847, 95% CI: 0.752-0.954) were independent risk factors for reintubation. In patients with 1, 2 and ≥3 SBT attempts, reintubation rates were 7.3%, 21.1% and 45.8%, respectively (P < .01). In patients with cough peak flow ≤60, 61-89 and ≥90 L/min, reintubation rates were 29.4%, 16.7% and 1.9%, respectively (P < .01). In patients with albumin ≤25, 26-30 and ≥31 g/L, reintubation rates were 32.4%, 11.1% and 9.8%, respectively (P = .01).

CONCLUSIONS

Multiple SBT attempts, weak cough and low albumin were associated with increased reintubation in medical patients. This study provides information for clinical practitioners in the consideration of patient extubation.

Evaluation of cough peak expiratory flow as a predictor of successful mechanical ventilation discontinuation: a narrative review of the literature

A crucial step in the transition from mechanical ventilation to extubation is the successful performance of a spontaneous breathing trial (SBT). The American College of Chest Physicians (ACCP) Guidelines recommend removal of the endotracheal tube upon successful completion of a SBT. However, this does not guarantee successful extubation as there remains a risk of re-intubation. Guidelines have outlined ventilator liberation protocols, selected use of non-invasive ventilation on extubation, early mobilization, and dynamic ventilator metrics to prevent and better predict extubation failure. However, a significant percentage of patients still fail mechanical ventilation discontinuation. A common reason for re-intubation is having a weak cough strength, which reflects the inability to protect the airway.

Evaluation of cough strength via objective measures using peak expiratory flow rate is a non-invasive and easily reproducible assessment which can predict extubation failure. We conducted a narrative review of the literature regarding use of cough strength as a predictive index for extubation failure risk. Results of our review show that cough strength, quantified objectively with a cough peak expiratory flow measurement (CPEF), is strongly associated with extubation success. Furthermore, various cutoff thresholds have been identified and can provide reasonable diagnostic accuracy and predictive power for extubation failure.

These results demonstrate that measurement of the CPEF can be a useful tool to predict extubation failure in patients on MV who have passed a SBT. In addition, the data suggest that this diagnostic modality may reduce ICU length of stay, ICU expenditures, and morbidity and mortality.

Plasma Concentrations of Soluble Suppression of Tumorigenicity-2 and Interleukin-6 Are Predictive of Successful Liberation From Mechanical Ventilation in Patients With the Acute Respiratory Distress Syndrome

OBJECTIVES

Soluble suppression of tumorigenicity-2 and interleukin-6 concentrations have been associated with the inflammatory cascade of acute respiratory distress syndrome. We determined whether soluble suppression of tumorigenicity-2 and interleukin-6 levels can be used as prognostic biomarkers to guide weaning from mechanical ventilation and predict the need for reintubation.

DESIGN, SETTING, AND PATIENTS

We assayed plasma soluble suppression of tumorigenicity-2 (n = 826) concentrations and interleukin-6 (n = 755) concentrations in the Fluid and Catheter Treatment Trial, a multicenter randomized controlled trial of conservative fluid management in acute respiratory distress syndrome. We tested whether soluble suppression of tumorigenicity-2 and interleukin-6 levels were associated with duration of mechanical ventilation, the probability of passing a weaning assessment, and the need for reintubation.

MEASUREMENTS AND MAIN RESULTS

In models adjusted for Acute Physiology and Chronic Health Evaluation score and other relevant variables, patients with higher day 0 and day 3 median soluble suppression of tumorigenicity-2 and interleukin-6 concentrations had decreased probability of extubation over time (day 0 soluble suppression of tumorigenicity-2: hazard ratio, 0.85; 95% CI, 0.72-1.00; p = 0.05; day 0 interleukin-6: hazard ratio, 0.64; 95% CI, 0.54-0.75; p < 0.0001; day 3 soluble suppression of tumorigenicity-2: hazard ratio, 0.64; 95% CI, 0.54-0.75; p < 0.0001; and day 3 interleukin-6: hazard ratio, 0.73; 95% CI, 0.62-0.85; p = 0.0001). Higher biomarker concentrations were also predictive of decreased odds of passing day 3 weaning assessments (soluble suppression of tumorigenicity-2: odds ratio, 0.62: 95% CI, 0.44-0.87; p = 0.006 and interleukin-6: odds ratio, 0.61; 95% CI, 0.43-0.85; p = 0.004) and decreased odds of passing a spontaneous breathing trial (soluble suppression of tumorigenicity-2: odds ratio, 0.45; 95% CI, 0.28-0.71; p = 0.0007 and interleukin-6 univariate analysis only: odds ratio, 0.55; 95% CI, 0.36-0.83; p = 0.005). Finally, higher biomarker levels were significant predictors of the need for reintubation for soluble suppression of tumorigenicity-2 (odds ratio, 3.23; 95% CI, 1.04-10.07; p = 0.04) and for interleukin-6 (odds ratio, 2.58; 95% CI, 1.14-5.84; p = 0.02).

CONCLUSIONS

Higher soluble suppression of tumorigenicity-2 and interleukin-6 concentrations are each associated with worse outcomes during weaning of mechanical ventilation and increased need for reintubation in patients with acute respiratory distress syndrome. Biomarker-directed ventilator management may lead to improved outcomes in weaning of mechanical ventilation in patients with acute respiratory distress syndrome.

Early postoperative management after lung transplantation: Results of an international survey

INTRODUCTION

Little data exist regarding optimal therapeutic strategies postoperatively after lung transplant (LTx). Current practice patterns rely on expert opinion and institutional experience resulting in nonuniform postoperative care. To better define current practice patterns, an international survey of LTx clinicians was conducted.

METHODS

A 30-question survey was sent to transplant clinicians via email to the International Society of Heart and Lung Transplantation open forum mailing list and directly to the chief transplant surgeon and pulmonologist of all LTx centers in the United States.

RESULTS

Fifty-two clinicians representing 10 countries responded to the survey. Sedatives use patterns included: opiates + propofol (57.2%), opiates + dexmedetomidine (18.4%), opiates + intermittent benzodiazepines (14.3%), opiates + continuous benzodiazepines (8.2%), and opiates alone (2%). About 40.4% reported no formal sedation scale was followed and 13.5% of programs had no formal policy on sedation and analgesia. A lung protective strategy was commonly employed, with 13.8%, 51.3%, and 35.9% of respondents using tidal volumes of <6 mL/kg ideal body weight (IBW), 6 mL/kg IBW, and 8 mL/kg IBW, respectively.

CONCLUSION

Practice patterns in the early postoperative care of lung transplant recipients differ considerably among centers. Many of the reported practices do not conform to consensus guidelines on management of critically ill patients.

Factors Influencing Weaning Older Adults From Mechanical Ventilation: An Integrative Review

This study aim was to describe the influences that affect weaning from mechanical ventilation among older adults in the intensive care unit (ICU). Adults older than 65 years comprised only 14.5% of the US population in 2014; however, they accounted up to 45% of all ICU admissions. As this population grows, the number of ICU admissions is expected to increase. One of the most common procedures for hospitalized adults 75 years and older is mechanical ventilation. An integrative review methodology was applied to analyze and synthesize primary research reports. A search for the articles was performed using the PubMed and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases; using the keywords and Boolean operators "older adults," "weaning," "mechanical ventilation," and intensive care unit. Although physiologic changes that occur with aging place older adults at higher risk for respiratory complications and mortality, there are many factors, other than chronological age, that can determine a patient's ability to be successfully weaned from mechanical ventilation. Of the 6 studies reviewed, all identified various predictors of weaning outcome, which included maximal inspiratory pressure, rapid shallow breathing index, fluid balance, comorbidity burden, severity of illness, emphysematous changes, and low serum albumin. Age, in and of itself, is not a predictor of weaning from mechanical ventilation. More studies are needed to describe the influences affecting weaning older adults from mechanical ventilation.

Tracheostomy, Extubation, Reintubation: Airway Management Decisions in Intubated Stroke Patients

BACKGROUND

Both delayed and premature extubation increase complication rate, the need for tracheostomy (TT), the duration of intensive care unit stay, and mortality. In this study, we therefore investigated factors associated with primary TT and predictors for extubation failure (EF) in a sample of severely affected ventilated stroke patients.

METHODS

One hundred eighty five intubated stroke patients were prospectively analyzed in this observational study. Patients not meeting predefined clinical and respiratory extubation criteria received a TT. All other patients were extubated and followed up for the need of reintubation. Characteristics of patients with and without extubation attempt were examined. Additionally, within the group of extubated patients, subgroups of successfully vs. unsuccessfully extubated patients were compared. Clinical factors associated with reintubation, including a previously established semi-quantitative airway score, were determined and predictors of EF were assessed.

RESULTS

Ninety-eight of 185 patients (53%) were primarily extubated; EF rate was 37% (36 patients). Eighty-seven (47%) were tracheostomized without a prior extubation attempt. Primarily tracheostomized patients had more severe strokes, which were more often hemorrhagic, presented with a lower level of consciousness, needed neurosurgical intervention more often, had a higher rate of obesity, and were more frequently intubated because of suspicion of compromised protective reflexes. EF was independently predicted by prior neurosurgical treatment and low airway management scores. No differences were found for the ability to follow simple commands and classical weaning criteria.

CONCLUSION

Airway management decisions in intubated stroke patients represent a clinical challenge. Classical weaning criteria and parameters reflecting the patient's state of consciousness are not reliably predictive of extubation success. Criteria more closely related to airway safety and secretion handling may provide the most relevant information and should therefore be assessed by specific clinical scoring systems.

How Mechanical Ventilation Measurement, Cutoff and Duration Affect Rapid Shallow Breathing Index Accuracy: A Randomized Trial

BACKGROUND

Decreased accuracy of the rapid shallow breathing index (RSBI) can stem from 1) the method used to obtain this index, 2) duration of mechanical ventilation (MV), and 3) the established cutoff point. The objective was to evaluate the values of RSBI determined by three different methods, using distinct MV times and cutoff points.

METHODS

This prospective study included 40 subjects. Before extubation, three different methods were employed to measure RSBI: pressure support ventilator (PSV) (PSV = 5 - 8 cm H₂O; positive end-expiratory pressure (PEEP) = 5 cm H₂O) (RSBI_MIN), automatic tube compensation (ATC) (PSV = 0, PEEP = 5 cm H₂O, and 100% tube compensation) (RSBI_ATC), and disconnected MV (RSBI_SP). The results were analyzed according to the MV period (less than or over 72 h) and to the outcome of extubation (< 72 h, successful and failed; > 72 h successful and failed). The accuracy of each method was determined at different cutoff points (105, 78, and 50 cycles/min/L).

RESULTS

The RSBI_MIN, RSBI_ATC, and RSBI_SP values in the group < 72 h were 38 ± 18, 45 ± 26 and 55 ± 22; in the group > 72 h, RSBI_SP value was higher than those of RSBI_ATC and RSBI_MIN (78 ± 29, 51 ± 19 and 39 ± 14) (P < 0.001). For patients with MV > 72 h who failed in removing MV, the RSBI_SP was higher (93 ± 28, 58 ± 18 and 41 ± 10) (P < 0.000), with greater accuracy at cutoff of 78.

CONCLUSION

RSBI_SP associated with cutoff point < 78 cycles/min/L seems to be the best strategy to identify failed extubation in subjects with MV for over 72 h.

Direct Two-Minute Unassisted Breathing Evaluation (DTUBE) is an Attractive Alternative to Longer Spontaneous Breathing Trials: A Prospective Observational Study

We sought to identify a simple bedside method to predict successful extubation outcomes that might be used during rounds. We hypothesized that a direct 2-minute unassisted breathing evaluation (DTUBE) could replace a longer spontaneous breathing trial (SBT). Data were pro-spectively collected on all patients endotracheally intubated for >48 hours nearing extubation in a tertiary center's mixed trauma/surgical intensive care unit from August 2012 to August 2013. The SBT was performed for at least 30 minutes at 40 per cent FiO2, PEEP 5, and PS 8. DTUBE was performed by physically disconnecting the intubated patient from the ventilator circuit for a 2-minute period of direct observation on room air. Successful extubation was defined freedom from ventilator for greater than 72 hours. Both SBTand DTUBE were performed 128 times, resulting in 90 extubations. The DTUBE correctly predicted success in 75/79 (94.9%) extubations versus 82/89 (92.1%) via SBT. No adverse effects were directly attributed to the DTUBE. The DTUBE is a rapid method of evaluating patients for extubation with prediction accuracy similar to the SBT.

Stress echocardiography in patients who experienced mechanical ventilation weaning failure

INTRODUCTION

Critically ill patients may suffer varying degrees of temporary myocardial dysfunction during respiratory weaning that could play an important role in weaning failure.

OBJECTIVES

In this study, we tried to assess the existence of temporary diastolic dysfunction during respiratory weaning.

METHODS

Inclusion period is from 2006 to 2015. In this study, we included 181 ventilated patients with cardiogenic shock that were being weaned from mechanical ventilation. Twenty of those patients were successfully weaned from mechanical ventilation, and the rest (161) experienced complications in their weaning process. All patients had a left ventricular ejection fraction >0.45 and E/E' ratio≤8, did not require vasoactive drugs at that time, and did not have remaining significant ischemic disease. We divided our patients into 3 groups, as follows: A, patients who could not tolerate a T-tube and required pressure-support ventilation (82); B, patients who successfully tolerated a T-tube period (20); and C, patients who could not tolerate spontaneous breathing modes of mechanical ventilation and remained on assisted mechanical ventilation. We performed stress echocardiography for the last two groups; using dobutamine to assess diastolic function and using ephedrine to evaluate functional mitral regurgitation (MR). We estimated pulmonary capillary wedge pressure through the E/E' ratio and the flow in the pulmonary veins.

RESULTS

In group A (ie, those patients who could not tolerate a T-tube trial), we observed an increase in the E/E' ratio (6.32±0.77 vs 15.2±6.65; P=.0001) and a worsening of strain (S) and strain rate (SR) (-13.6±1.80 vs -11.88±5.6, P=.0001; and -1.3±1.28 vs -0.95±0.38, P=.0001; respectively). We did not observe a change in the E/E' ratio during stress echocardiogram on those patients with successful weaning from mechanical ventilation (7.41±0.43 vs 8.38±4.57, P=.001). However, we did see in this group an increased peak velocity of the S wave and of SR (-16.11±08.72 vs -19.89±5.62 and -1.48±0.23 vs -1.59±0.21, P=.001; respectively). In 42 weaning failure patients, the dobutamine echocardiography showed an increased E/E' ratio (7.41±0.43 vs 15.98±7.98; P=.0001) and deterioration of S (-15.41±09.56 vs -12.72±6.55; P=.0001) and SR (-1.41±0.78 vs -1.22±0.65; P=.0001). In 37 patients without systolic or diastolic impairment and functional MR grade >2, ephedrine echocardiography showed an increase of effective regurgitant volume (29.56±11.32 mL vs 46.56±0.13 mL, P=.0001) and effective regurgitant orifice area (0.19±0.09 cm² vs 0.31±0.09 cm², P=.0001).

CONCLUSIONS

Stress echocardiography may be helpful in detecting silent diastolic and systolic dysfunction or severe MR that could have a major impact on respiratory weaning.

Introducing the Comprehensive Unit-based Safety Program for mechanically ventilated patients in Saudi Arabian Intensive Care Units

Over the past decade, there have been major improvements to the care of mechanically ventilated patients (MVPs). Earlier initiatives used the concept of ventilator care bundles (sets of interventions), with a primary focus on reducing ventilator-associated pneumonia. However, recent evidence has led to a more comprehensive approach: The ABCDE bundle (Awakening and Breathing trial Coordination, Delirium management and Early mobilization). The approach of the Comprehensive Unit-based Safety Program (CUSP) was developed by patient safety researchers at the Johns Hopkins Hospital and is supported by the Agency for Healthcare Research and Quality to improve local safety cultures and to learn from defects by utilizing a validated structured framework. In August 2015, 17 Intensive Care Units (ICUs) (a total of 271 beds) in eight hospitals in the Kingdom of Saudi Arabia joined the CUSP for MVPs (CUSP 4 MVP) that was conducted in 235 ICUs in 169 US hospitals and led by the Johns Hopkins Armstrong Institute for Patient Safety and Quality. The CUSP 4 MVP project will set the stage for cooperation between multiple hospitals and thus strives to create a countrywide plan for the management of all MVPs in Saudi Arabia.

Can recombinant human thrombomodulin increase survival among patients with severe septic-induced disseminated intravascular coagulation: a single-centre, open-label, randomised controlled trial

OBJECTIVE

To determine whether treatment with recombinant human thrombomodulin (rhTM) increases survival among patients with severe septic-induced disseminated intravascular coagulation (DIC).

DESIGN

Single-centre, open-label, randomised controlled trial.

SETTING

Single tertiary hospital.

PARTICIPANT

92 patients with severe septic-induced DIC.

INTERVENTIONS

Patients with DIC scores ≥4, as defined by the Japanese Association of Acute Medicine, were diagnosed with DIC. The envelope method was used for randomisation. The treatment group (rhTM group, n=47) was intravenously treated with rhTM within 24 hours of admission (day 0), and the control group (n=45) did not receive any anticoagulants, except in cases of deep venous thrombosis and pulmonary embolism.

PRIMARY AND SECONDARY MEASUREMENTS

Data were collected on days 0 (admission), 1, 2, 3, 5, 7 and 10. The primary outcome was survival at 28 and 90 days. The secondary end points comprised changes in DIC scores, platelet counts, d-dimer, antithrombin III and C reactive protein levels, and Sequential Organ Failure Assessment (SOFA) scores. All analyses were conducted on an intent-to-treat basis.

MAIN RESULTS

The 28-day survival rates were 84% and 83% in the control and rhTM groups, respectively (p=0.745, log-rank test). The 90-day survival rates were 73% and 72% in the control and rhTM groups, respectively (p=0.94, log-rank test). Meanwhile, the rates of recovery from DIC (<4) were significantly higher in the rhTM group than in the control group (p=0.001, log-rank test). Relative change from baseline of d-dimer levels was significantly lower in the rhTM group than in the control group, on days 3 and 5.

CONCLUSIONS

rhTM treatment decreased d-dimer levels and facilitated DIC recovery in patients with severe septic-induced DIC. However, the treatment did not improve survival in this cohort.

TRIAL REGISTRATION NUMBER

UMIN000008339.

Holistic Care for Patients During Weaning from Mechanical Ventilation: A Qualitative Study

BACKGROUND

Weaning patients from mechanical ventilation is a complex and highly challenging process. It requires continuity of care, the overall assessment of patients, and a focus on all aspects of patients' needs by critical care nurses.

OBJECTIVES

The aim of the present study was to explore holistic care while patients are being weaned from mechanical ventilation from the perspective of the critical care nurses.

METHODS

The study was carried out in the intensive care units (ICUs) of six hospitals in Ahvaz, Iran, from 2014 to 2015. In this qualitative study, 25 ICU staff including nurses, nurse managers, and nurse educators were selected by means of purposive sampling. Semi-structured interviews were used for data collection. The interview transcripts were then analyzed using qualitative content analysis.

RESULTS

The four main themes that emerged to explain nurses' experiences of holistic care when weaning patients from mechanical ventilation include continuous care, a holistic overview of the patient, promoting human dignity, and the overall development of well-being.

CONCLUSIONS

It was found that avoiding routine pivotal expertise, increasing consciousness of the nonphysical aspects of patients while providing treatment and presenting exclusive care, utilizing experienced ICU nurses, and placing more emphasis on effective communication with patients in order to honor them as human beings can all enhance the holistic quality of care.

Spontaneous breathing trial and post-extubation work of breathing in morbidly obese critically ill patients

Background

Predicting whether an obese critically ill patient can be successfully extubated may be specially challenging. Several weaning tests have been described but no physiological study has evaluated the weaning test that would best reflect the post-extubation inspiratory effort.

Methods

This was a physiological randomized crossover study in a medical and surgical single-center Intensive Care Unit, in patients with body mass index (BMI) >35 kg/m² who were mechanically ventilated for more than 24 h and underwent a weaning test. After randomization, 17 patients were explored using five settings : pressure support ventilation (PSV) 7 and positive end-expiratory pressure (PEEP) 7 cmH2O; PSV 0 and PEEP 7cmH2O; PSV 7 and PEEP 0 cmH2O; PSV 0 and PEEP 0 cmH2O; and a T piece, and after extubation. To further minimize interaction between each setting, a period of baseline ventilation was performed between each step of the study. We hypothesized that the post-extubation work of breathing (WOB) would be similar to the T-tube WOB.

Results

Respiratory variables and esophageal and gastric pressure were recorded. Inspiratory muscle effort was calculated as the esophageal and trans-diaphragmatic pressure time products and WOB. Sixteen obese patients (BMI 44 kg/m² ± 8) were included and successfully extubated. Post-extubation inspiratory effort, calculated by WOB, was 1.56 J/L ± 0.50, not statistically different from the T piece (1.57 J/L ± 0.56) or PSV 0 and PEEP 0 cmH₂O (1.58 J/L ± 0.57), whatever the index of inspiratory effort. The three tests that maintained pressure support statistically underestimated post-extubation inspiratory effort (WOB 0.69 J/L ± 0.31, 1.15 J/L ± 0.39 and 1.09 J/L ± 0.49, respectively, p < 0.001). Respiratory mechanics and arterial blood gases did not differ between the five tests and the post-extubation condition.

Conclusions

In obese patients, inspiratory effort measured during weaning tests with either a T-piece or a PSV 0 and PEEP 0 was not different to post-extubation inspiratory effort. In contrast, weaning tests with positive pressure overestimated post-extubation inspiratory effort.

Trial registration

Clinical trial.gov (reference NCT01616901), 2012, June 4th

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1457-4) contains supplementary material, which is available to authorized users.

Nursing Strategies for Effective Weaning of the Critically Ill Mechanically Ventilated Patient

The risks imposed by mechanical ventilation can be mitigated by nurses' use of strategies that promote early but appropriate reduction of ventilatory support and timely extubation. Weaning from mechanical ventilation is confounded by the multiple impacts of critical illness on the body's systems. Effective weaning strategies that combine several interventions that optimize weaning readiness and assess readiness to wean, and use a weaning protocol in association with spontaneous breathing trials, are likely to reduce the requirement for mechanical ventilatory support in a timely manner. Weaning strategies should be reviewed and updated regularly to ensure congruence with the best available evidence.

Can diaphragmatic ultrasonography performed during the T-tube trial predict weaning failure? The role of diaphragmatic rapid shallow breathing index

Background

The rapid shallow breathing index (RSBI), which is the ratio between respiratory rate (RR) and tidal volume (VT), is one of the most widely used indices to predict weaning outcome. Whereas the diaphragm plays a fundamental role in generating VT, in the case of diaphragmatic dysfunction the inspiratory accessory muscles may contribute. If this occurs during a weaning trial, delayed weaning failure is likely since the accessory muscles are more fatigable than the diaphragm. Hence, we hypothesised that the traditional RSBI could be implemented by substituting VT with the ultrasonographic evaluation of diaphragmatic displacement (DD). We named the new index the diaphragmatic-RSBI (D-RSBI). The aim of this study was to compare the ability of the traditional RSBI and D-RSBI to predict weaning failure in ready-to-wean patients.

Methods

We performed a prospective observational study. During a T-tube spontaneous breathing trial (SBT) we simultaneously evaluated right hemidiaphragm displacement (i.e., DD) by using M-mode ultrasonography as well as the RSBI. Outcome of the weaning attempt, length of mechanical ventilation, length of intensive care unit and hospital stay, and hospital mortality were recorded. Receiver operator characteristic (ROC) curves were used to evaluate the diagnostic accuracy of D-RSBI and RSBI.

Results

We enrolled 51 patients requiring mechanical ventilation for more than 48 h who were ready to perform a SBT. Most of the patients, 34 (66 %), were successfully weaned from mechanical ventilation. When considering the 17 patients that failed the weaning attempt, 11 (64 %) had to be reconnected to the ventilator during the SBT, three (18 %) had to be re-intubated within 48 h of extubation, and three (18 %) required non-invasive ventilation support within 48 h of extubation. The areas under the ROC curves for D-RSBI and RSBI were 0.89 and 0.72, respectively (P = 0.006).

Conclusions

D-RSBI (RR/DD) was more accurate than traditional RSBI (RR/VT) in predicting the weaning outcome.

Trial registration

Our clinical trial was retrospectively registered with ClinicalTrials.gov (identifier: NCT02696018). ClinicalTrials.gov processed our record on 25 February 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1479-y) contains supplementary material, which is available to authorized users.

Management of acute hypercapnic respiratory failure

PURPOSE OF REVIEW

The objective of this article is to review the most recent literature regarding the management of acute hypercapnic respiratory failure (AHRF).

RECENT FINDINGS

In the field of AHRF management, noninvasive ventilation (NIV) has become the standard method of providing primary mechanical ventilator support. Recently, extracorporeal carbon dioxide removal (ECCO2R) devices have been proposed as new therapeutic option.

SUMMARY

NIV is an effective strategy in specific settings and in selected population with AHRF. To date, evidence on ECCO2R is based only on case reports and case-control trials. Although the preliminary results using ECCO2R to decrease the rate of NIV failure and to wean hypercapnic patients from invasive ventilation are remarkable; further randomized studies are needed to assess the effects of this technique on both short-term and long-term clinical outcomes.

Mechanical Ventilator Discontinuation Process

The goal of this article is to discuss approaches to discontinuing invasive mechanical ventilation in a general intensive care unit (ICU) population. It considers approaches in which the clinician expects patient survival, as well as those that do not. Additionally, approaches to acute and chronic critical illness are included.

Change in Diaphragmatic Thickness During the Respiratory Cycle Predicts Extubation Success at Various Levels of Pressure Support Ventilation

PURPOSE

Ultrasonographic assessment of diaphragm function with patients on low levels of pressure support (PS) predicts extubation outcomes, but similar information regarding extubation success under other conditions is lacking. The purpose of this study was to determine whether ultrasound (US) measurements of the diaphragm made on various levels of PS can predict time until successful extubation.

METHODS

Fifty-six intubated patients underwent ultrasound of the right hemidiaphragm during a PS wean at varying levels of pressure support (PS 5/5 cm of H2O, 10/5 cm of H2O, and 15/5 cm of H2O). The diaphragm was visualized using a 7.5-10 mHz transducer in the zone of apposition of the diaphragm to the lower rib cage. The percent change in diaphragm thickness between end-expiration and end-inspiration (∆tdi%) was calculated at each level of PS.

RESULTS

∆tdi% >20 is a robust predictor of extubation success within 48 h of US at PS 5/5 cm of H2O and 10/5 cm of H2O (sensitivity 84.6 and 88.9 % and specificity 79.0 and 75.0 %, respectively). At PS greater than 10/5 cm of H2O, its predictive power was greatly diminished. Of nine patients who were extubated with ∆tdi% below the cutoff, 66.6 % required emergent reintubation in the next two days.

CONCLUSIONS

Diaphragm US is a valid predictor of extubation success at some but not all PS settings. Using a ∆tdi% of 20 % on PS levels up to 10/5 cm of H2O may reduce both unnecessarily prolonged intubations and prevent emergent reintubations.

Predictors of extubation success in acute ischemic stroke patients

BACKGROUND

Acute ischemic stroke (AIS) patients often undergo intubation and mechanical ventilation (MV). Prolonged intubation and MV have disadvantages and complications. Conventional extubation criteria based only on respiratory parameters are insufficient to guide extubation practices in stroke patients where capacity for airway protection is a major concern.

OBJECTIVE

To identify clinical and neuroanatomical markers of successful extubation in AIS patients requiring MV.

METHODS

Retrospective review of tertiary care hospital patient database from May 2009-November 2012 to identify consecutive patients with AIS intubated during hospitalization. We assessed the effect of age, sex, baseline National Institutes of Health Stroke Scale (NIHSS) score, level of consciousness, facial weakness, dysarthria, neglect, infarct location, dysphagia, respiratory parameters and history of pneumonia on successful extubation by hospital discharge using multivariate logistic regression analysis.

RESULTS

112 subjects met study criteria and were included in the analysis. Age and NIHSS scores (mean±standard deviation) were 74.5±16.1years and 19±9.8, respectively; 56% were women. In multivariate analysis, NIHSS score≤15 (Odds Ratio 4.6, 95% Confidence Interval 1.9-11.3, p<0.001) and absence of dysarthria prior to intubation (Odds Ratio 3.0, 95% Confidence interval 1.1-8.3, p=0.04) were independently associated with successful extubation. Conventional respiratory parameters had no effect on extubation success in this cohort.

CONCLUSIONS

Milder stroke and absence of dysarthria prior to intubation were independently associated with extubation success. Our findings could help inform extubation practices in patients with AIS though prospective validation is necessary.

Preadmission tracheostomy is associated with better outcomes in patients with prolonged mechanical ventilation in the postintensive care respiratory care setting

BACKGROUND/PURPOSE

Prolonged mechanical ventilation (PMV) is the most common situation where tracheostomy is indicated for intensive care unit (ICU) patients. However, it is unknown if this procedure confers survival benefits on PMV patients in a post-ICU setting.

METHODS

Patients who were admitted to the specialized weaning unit from 2005 to 2008 and received PMV were included in this study. On admission, data pertaining to patient characteristics, physiologic status, and type of artificial airway (tracheostomy vs. no tracheostomy) were obtained. Outcomes of tracheostomized and nontracheostomized patients were evaluated using multivariate Cox proportional hazards and propensity score-matching models. The primary outcome of interest was 1-year survival.

RESULTS

A total of 401 patients (mean age 74.4 years, 204 male) were identified. In multivariate analyses, higher Acute Physiology and Chronic Health Evaluation II score [hazard ratio (HR) = 1.061, 95% confidence interval (CI) = 1.016-1.107] and presence of comorbidities, including congestive heart failure (HR = 1.562, 95% CI = 1.119-2.181), malignancy (HR = 1.942, 95% CI = 1.306-2.885), and liver cirrhosis (HR = 2.373, 95% CI = 1.015-5.544), were independently associated with 1-year mortality. An association between having tracheostomy and a better 1-year outcome was observed (HR = 0.625, 95% CI = 0.453-0.863). The matched cohort study also demonstrated a favorable 1-year survival for tracheostomized patients, and these patients had significantly lower in-hospital mortality (24% vs. 36%, p = 0.049) and risk of ventilator-associated pneumonia (10% vs. 20%, p = 0.030) than nontracheostomized ones.

CONCLUSION

Preadmission tracheostomy may be associated with better outcomes of PMV patients in a post-ICU respiratory care setting. The findings suggest that this procedure should be recommended before PMV patients are transferred to specialized weaning units.

Left Ventricular Diastolic Dysfunction—An Independent Risk Factor for Weaning Failure from Mechanical Ventilation

The objective of this study was to investigate the contribution of left ventricular (LV) diastolic dysfunction to weaning failure, along with the levels of the currently used cardiac biomarkers. Forty-two mechanically ventilated patients, who fulfilled criteria for weaning from mechanical ventilation (MV), underwent a two-hour spontaneous breathing trial (SBT). Transthoracic echocardiography (TTE) was performed before the start of the SBT. The grade of LV diastolic dysfunction was assessed by pulsed-wave Doppler and tissue Doppler imaging at the level of the mitral valve. Haemodynamic and respiratory parameters were recorded. Blood levels of B-type natriuretic peptide (BNP), troponin I, creatine kinase–MB, and myoglobin were measured on MV and at the end of the SBT. Weaning success was defined as the patient's ability to tolerate spontaneous breathing for more than 48 hours. Fifteen patients failed to wean. LV diastolic dysfunction was significantly associated with weaning failure ( P <0.001). The grade of diastolic dysfunction was significantly correlated with BNP levels both on MV and at the end of the SBT ( P <0.001, r = 0.703 and P <0.001, r = 0.709, respectively). BNP levels on MV were lower in patients who successfully weaned compared to those who did not (361 ± 523 ng/l versus 643 ± 382 ng/l respectively, P=0.008). The presence of diastolic dysfunction was independently associated with weaning failure (odds ratio [OR] 11.23, confidence interval [CI] 1.16–109.1, P=0.037) followed by respiratory frequency/tidal volume (OR 1.05, CI 1.00–1.10, P=0.048). Therefore, assessment of LV diastolic function before the start of weaning could be useful to identify patients at risk of weaning failure.

Factors Predicting Successful Discontinuation of Continuous Renal Replacement Therapy

This multicentre, retrospective observational study was conducted from January 2010 to December 2010 to determine the optimal time for discontinuing continuous renal replacement therapy (CRRT) by evaluating factors predictive of successful discontinuation in patients with acute kidney injury. Analysis was performed for patients after CRRT was discontinued because of renal function recovery. Patients were divided into two groups according to the success or failure of CRRT discontinuation. In multivariate logistic regression analysis, urine output at discontinuation, creatinine level and CRRT duration were found to be significant variables (area under the receiver operating characteristic curve for urine output, 0.814). In conclusion, we found that higher urine output, lower creatinine and shorter CRRT duration were significant factors to predict successful discontinuation of CRRT.

The Care-Integrated Concentration Meditation Program for Patients With Weaning Difficulty: A Pilot Study

Because of the multifaceted process of weaning patients with prolonged mechanical ventilation, enhancing weaning success remains a challenge. The Care-Integrated Concentration Meditation Program was developed on the basis of Buddhist philosophy and implemented to determine its procedural feasibility. A qualitative case study with 3 participants was conducted, and the process and initial outcomes were evaluated.

Clinical Impact of Ventilation Duration in Patients with Stroke Undergoing Interventional Treatment under General Anesthesia: The Shorter the Better?

BACKGROUND AND PURPOSE

Whether general anesthesia for neurothrombectomy in patients with ischemic stroke has a negative impact on clinical outcome is currently under discussion. We investigated the impact of early extubation and ventilation duration in a cohort that underwent thrombectomy under general anesthesia.

MATERIALS AND METHODS

We analyzed 103 consecutive patients from a prospective stroke registry. They met the following criteria: CTA-proved large-vessel occlusion in the anterior circulation, ASPECTS above 6 on presenting cranial CT, revascularization by thrombectomy with the patient under general anesthesia within 6 hours after onset of symptoms, and available functional outcome (mRS) 90 days after onset.

RESULTS

The mean ventilation time was 128.07 ± 265.51 hours (median, 18.5 hours; range, 1-1244.7 hours). Prolonged ventilation was associated with pneumonia during hospitalization and unfavorable functional outcome (mRS ≥3) and death at follow-up (Mann-Whitney U test; P ≤ .001). According to receiver operating characteristic analysis, a cutoff after 24 hours predicted unfavorable functional outcome with a sensitivity and specificity of 60% and 78%, respectively. Our results imply that delayed extubation was not associated with a less favorable clinical outcome compared with immediate extubation after the procedure.

CONCLUSIONS

Short ventilation times are associated with a lower pneumonia rate and more favorable clinical outcome. Cautious interpretation of our data implies that whether patients are extubated immediately after the procedure is irrelevant for clinical outcome as long as ventilation does not exceed 24 hours.

The Utility of the Swine Model to Assess Biological Rhythms and Their Characteristics during Different Stages of Residence in a Simulated Intensive Care Unit: A Pilot Study

The purpose of this pilot study was to explore the utility of the mammalian swine model under simulated intensive care unit (sICU) conditions and mechanical ventilation (MV) for assessment of the trajectory of circadian rhythms of sedation requirement, core body temperature (CBT), pulmonary mechanics (PM) and gas exchange (GE). Data were collected prospectively with an observational time-series design to describe and compare circadian rhythms of selected study variables in four swine mechanically ventilated for up to seven consecutive days. We derived the circadian (total variance explained by rhythms of τ between 20 and 28 h)/ultradian (total variance explained by rhythms of τ between 1 and <20 h) bandpower ratio to assess the robustness of circadian rhythms, and compare findings between the early (first 3 days) and late (subsequent days) sICU stay. All pigs exhibited statistically significant circadian rhythms (τ between 20 and 28 h) in CBT, respiratory rate and peripheral oxygen saturation, but circadian rhythms were detected less frequently for sedation requirement, spontaneous minute volume, arterial oxygen tension, arterial carbon dioxide tension and arterial pH. Sedation did not appear to mask the circadian rhythms of CBT, PM and GE. Individual subject observations were more informative than group data, and provided preliminary evidence that (a) circadian rhythms of multiple variables are lost or desynchronized in mechanically ventilated subjects, (b) robustness of circadian rhythm varies with subject morbidity and (c) healthier pigs develop more robust circadian rhythm profiles over time in the sICU. Comparison of biological rhythm profiles among sICU subjects with similar severity of illness is needed to determine if the results of this pilot study are reproducible. Identification of consistent patterns may provide insight into subject morbidity and timing of such therapeutic interventions as weaning from MV.

Diaphragm ultrasound as a new method to predict extubation outcome in mechanically ventilated patients

AIM

To evaluate role of diaphragmatic thickening and excursion, assessed ultrasonographically, in predicting extubation outcome.

METHODS

Fifty-four patients who successfully passed spontaneous breathing trial (SBT) were enrolled. They were assessed by ultrasound during SBT evaluating diaphragmatic excursion, diaphragmatic thickness (Tdi) at end inspiration, at end expiration and diaphragmatic thickness fraction (DTF%). Simultaneously traditional weaning parameters were recorded. Patients were followed up for 48h after extubation.

RESULTS

Out of 54 included patients, 14 (25.9%) failed extubation. Diaphragmatic excursion, Tdi at end inspiration, at end expiration and DTF% were significantly higher in the successful group compared to those who failed extubation (p<0.05). Cutoff values of diaphragmatic measures associated with successful extubation were ≥10.5mm for diaphragmatic excursion, ≥21mm for Tdi at end inspiration, ≥10.5mm for Tdi at end expiration, ≥34.2% for DTF% giving 87.5%, 77.5%, 80% and 90% sensitivity respectively and 71.5%, 86.6%, 50% and 64.3% specificity respectively. Combining diaphragmatic excursion ≥10.5mm and Tdi at end inspiration ≥21mm decreased sensitivity to 64.9% but increased specificity to 100%. Rapid shallow breathing index (RSBI) <105 had 90% sensitivity but 18.7% specificity.

CONCLUSION

Ultrasound evaluation of diaphragmatic excursion and thickness at end inspiration could be a good predictor of extubation outcome in patients who passed SBT. It is recommended to consider the use of these parameters with RSBI consequently to improve extubation outcome.

Reflex cough PEF as a predictor of successful extubation in neurological patients

Objective:

To evaluate the use of reflex cough PEF as a predictor of successful extubation in neurological patients who were candidates for weaning from mechanical ventilation.

Methods:

This was a cross-sectional study of 135 patients receiving mechanical ventilation for more than 24 h in the ICU of Cristo Redentor Hospital, in the city of Porto Alegre, Brazil. Reflex cough PEF, the rapid shallow breathing index, MIP, and MEP were measured, as were ventilatory, hemodynamic, and clinical parameters.

Results:

The mean age of the patients was 47.8 ± 17 years. The extubation failure rate was 33.3%. A reflex cough PEF of &lt; 80 L/min showed a relative risk of 3.6 (95% CI: 2.0-6.7), and the final Glasgow Coma Scale score showed a relative risk of 0.64 (95% CI: 0.51-0.83). For every 1-point increase in a Glasgow Coma Scale score of 8, there was a 36% reduction in the risk of extubation failure.

Conclusions:

Reflex cough PEF and the Glasgow Coma Scale score are independent predictors of extubation failure in neurological patients admitted to the ICU.

Airway accidents in critical care unit: A 3-year retrospective study in a Public Teaching Hospital of Eastern India

Background:

Although tracheal tubes are essential devices to control and protect airway in a critical care unit (CCU), they are not free from complications.

Aims:

To document the incidence and nature of airway accidents in the CCU of a government teaching hospital in Eastern India.

Methods:

Retrospective analysis of all airway accidents in a 5-bedded (medical and surgical) CCU. The number, types, timing, and severity of airway accidents were analyzed.

Results:

The total accident rate was 19 in 233 intubated and/or tracheostomized patients over 1657 tube days (TDs) during 3 years. Fourteen occurred in 232 endotracheally intubated patients over 1075 endotracheal tube (ETT) days, and five occurred in 44 tracheostomized patients over 580 tracheostomy TDs. Fifteen accidents were due to blocked tubes. Rest four were unplanned extubations (UEs), all being accidental extubations. All blockages occurred during night shifts and all UEs during day shifts. Five accidents were mild, the rest moderate. No major accident led to cardiorespiratory arrest or death. All blockages occurred after 7^th day of intubation. The outcome of accidents were more favorable in tracheostomy group compared to ETT group (P = 0.001).

Conclusions:

The prevalence of airway accidents was 8.2 accidents per 100 patients. Blockages were the most common accidents followed by UEs. Ten out of the 15 blockages and all 4 UEs were in endotracheally intubated patients. Tracheostomized patients had 5 blockages and no UEs.

Underestimation of Patient Breathlessness by Nurses and Physicians during a Spontaneous Breathing Trial

RATIONALE

Breathlessness is a prevalent and distressing symptom in intensive care unit patients. There is little evidence of the ability of healthcare workers to assess the patient's experiences of breathing. Patient perception of breathing is essential in symptom management, and patient perception during a spontaneous breathing trial (SBT) might be related to extubation success.

OBJECTIVES

To assess mechanically ventilated patients' experiences of breathlessness during SBT.

METHODS

This was a prospective observational multicenter study of 100 mechanically ventilated patients. We assessed the agreement between nurses, physicians, and patients' 11-point Numerical Rating Scales scores of breathlessness, perception of feeling secure, and improvement of respiratory function at the end of an SBT (most performed with some level of support). We also determined the association between breathlessness and demographic factors or respiratory observations.

MEASUREMENTS AND MAIN RESULTS

Sixty-two patients (62%) reported moderate or severe breathlessness (Numerical Rating Scales ≥ 4). The median intensity of breathlessness reported by patients was five compared with two by nurses and physicians (P < 0.001). Patients felt less secure and reported less improvement of respiratory function compared with nurses' and physicians' ratings. About half of the nurses and physicians underestimated breathlessness (difference score, ≤-2) compared with the patients' self-reports. Underestimation of breathlessness was not associated with professional competencies. There were no major differences in objective assessments of respiratory function in patients with moderate or severe breathlessness, and no apparent relationship between breathlessness during the SBT and extubation outcome.

CONCLUSIONS

Patients reported higher breathlessness after SBT compared with nurses and physicians. Clinical trial registered with www.clinicaltrials.gov (NCT 01928277).

Practice Variation in Spontaneous Breathing Trial Performance and Reporting

Background. Spontaneous breathing trials (SBTs) are standard of care in assessing extubation readiness; however, there are no universally accepted guidelines regarding their precise performance and reporting. Objective. To investigate variability in SBT practice across centres. Methods. Data from 680 patients undergoing 931 SBTs from eight North American centres from the Weaning and Variability Evaluation (WAVE) observational study were examined. SBT performance was analyzed with respect to ventilatory support, oxygen requirements, and sedation level using the Richmond Agitation Scale Score (RASS). The incidence of use of clinical extubation criteria and changes in physiologic parameters during an SBT were assessed. Results. The majority (80% and 78%) of SBTs used 5 cmH₂O of ventilator support, although there was variability. A significant range in oxygenation was observed. RASS scores were variable, with RASS 0 ranging from 29% to 86% and 22% of SBTs performed in sedated patients (RASS < −2). Clinical extubation criteria were heterogeneous among centres. On average, there was no change in physiological variables during SBTs. Conclusion. The present study highlights variation in SBT performance and documentation across and within sites. With their impact on the accuracy of outcome prediction, these results support efforts to further clarify and standardize optimal SBT technique.

Brazilian recommendations of mechanical ventilation 2013. Part 2

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Out-of-bed extubation: a feasibility study

OBJECTIVE

In clinical intensive care practice, weaning from mechanical ventilation is accompanied by concurrent early patient mobilization. The aim of this study was to compare the success of extubation performed with patients seated in an armchair compared to extubation with patients in a supine position.

METHODS

A retrospective study, observational and non-randomized was conducted in a mixed-gender, 23-bed intensive care unit. The primary study outcome was success of extubation, which was defined as the patient tolerating the removal of the endotracheal tube for at least 48 hours. The differences between the study groups were assessed using Student's t-test and chi-squared analysis.

RESULTS

Ninety-one patients were included from December 2010 and June 2011. The study population had a mean age of 71 years ± 12 months, a mean APACHE II score of 21±7.6, and a mean length of mechanical ventilation of 2.6±2 days. Extubation was performed in 33 patients who were seated in an armchair (36%) and in 58 patients in a supine position (64%). There were no significant differences in age, mean APACHE II score or length of mechanical ventilation between the two groups, and a similar extubation success rate was observed (82%, seated group versus 85%, supine group, p>0.05). Furthermore, no significant differences were found between the two groups in terms of post-extubation distress, need for tracheostomy, duration of mechanical ventilation weaning, or intensive care unit stay.

CONCLUSION

Our results suggest that the clinical outcomes of patients extubated in a seated position are similar to those of patients extubated in a supine position. This new practice of seated extubation was not associated with adverse events and allowed extubation to occur simultaneously with early mobilization.

Initial synchronized intermittent mandatory ventilation versus assist/control ventilation in treatment of moderate acute respiratory distress syndrome: a prospective randomized controlled trial

BACKGROUND

Assist/control (A/C) ventilation may induce delirium in patients with acute respiratory distress syndrome (ARDS). We conducted a trial to determine whether initial synchronized intermittent mandatory ventilation with pressure support (SIMV + PS) could improve clinical outcomes in these patients.

METHODS

Intubated patients with moderate ARDS were enrolled and we compared SIMV + PS with A/C. Identical sedation, analgesia and ventilation strategies were performed. The co-primary outcomes were early (≤72 h) partial pressure of arterial oxygen to fraction of inspired oxygen (PaO2/FiO2) and incidence of delirium. The secondary outcomes were all-cause in-hospital mortality, dosages of analgesics and sedatives, incidence of patient-ventilator asynchrony, and duration of mechanical ventilation and hospital stay.

RESULTS

We screened 2,684 patients and 40 patients were enrolled in our study. In SIMV + PS, early (≤72 h) PaO2/FiO2 was greater improved than that at baseline and that in A/C (P<0.05) with lower positive end-expiratory pressure (PEEP) (8.7±3.0 vs. 10.3±3.2, P<0.001) and FiO2 (58%±18% vs. 67%±19%, P<0.001). We found more SIMV + PS success (defined as SIMV + PS successfully applied without switching to A/C) (100.0% vs. 16.7%, P<0.001), less male (46.3% vs. 85.7%, P=0.015) and pulmonary etiology of ARDS (53.8% vs. 92.9%, P=0.015), and lower PEEP (9.1±3.1 vs. 10.3±3.3, P=0.004) and FiO2 (58%±19% vs. 71%±19%, P<0.001) in survival patients. However, there were no significant differences in incidence of delirium and mortality, dosages of analgesics and sedatives, incidence of patient-ventilator asynchrony, duration of mechanical ventilation and hospital stay (P>0.05).

CONCLUSIONS

In patients with moderate ARDS, SIMV + PS can safely and effectively improve oxygenation, but does not decrease mortality, incidence of delirium and patient-ventilator asynchrony, dosages of analgesics and sedatives, and duration of mechanical ventilation and hospital stay.

Extubation outcome after a successful spontaneous breathing trial: A multicenter validation of a 3-factor prediction model

The aim of the present study was to validate, and if necessary update, a predictive model previously developed using a classification and regression tree (CART) algorithm for predicting successful extubation (ES) using a new cohort. This prospective cohort study enrolled adults admitted to 10 intensive care units, who had successfully passed a spontaneous breathing trial (SBT) and were considered ready for extubation. After extubation, the patients were followed up for 48 h. The primary outcome measure was ES, defined as the ability to maintain spontaneous unassisted breathing for >48 h after extubation. The 3-factor CART model was applied to patients in this cohort. The predicted probability of ES for each patient in this validation cohort was calculated based on the original CART model using the Laplace correction method. The performance was assessed by discrimination and calibration. A decision curve analysis was used assess the clinical net benefit (NB). Extubation failure (EF) occurred in 90/530 patients (17%). Among the 90 patients, 72 (13.6%) were reintubated, while 18 patients remained on rescue noninvasive ventilation within 48 h after extubation. The original CART model showed high discrimination but only moderate calibration with predicted probabilities that were systematically lower than expected. The original CART model was updated, and the updated model preserved excellent discrimination (area under the receiver operating characteristic curve, 0.91; 95% confidence interval, 0.87 to 0.93), but exhibited near-perfect calibration (calibration slope, 1; intercept, 0). Between threshold probabilities of 50 and 80%, the NB of using this updated model is significantly improved compared with the current strategy. The updated CART model may be used to estimate the predicted probability of ES after a successful SBT for individual patients. Applying this model appears to produce a substantial clinical consequence with regard to potential reduction in unexpected EFs.

Effect of public reporting on intensive care unit discharge destination and outcomes

RATIONALE

Public reporting of hospital performance is designed to improve healthcare outcomes by promoting quality improvement and informing consumer choice, but these programs may carry unintended consequences.

OBJECTIVE

To determine whether publicly reporting in-hospital mortality rates for intensive care unit (ICU) patients influenced discharge patterns or mortality.

METHODS

We performed a retrospective cohort study taking advantage of a natural experiment in which California, but not other states, publicly reported hospital-specific severity-adjusted ICU mortality rates between 2007 and 2012. We used multivariable logistic regression adjusted for patient, hospital, and regional characteristics to compare mortality rates and discharge patterns between California and states without public reporting for Medicare fee-for-service ICU admissions from 2005 through 2009 using a difference-in-differences approach.

MEASUREMENTS AND MAIN RESULTS

We assessed discharge patterns using post-acute care use and acute care hospital transfer rates and mortality using in-hospital and 30-day mortality rates. The study cohort included 936,063 patients admitted to 646 hospitals. Compared with control subjects, admission to a California ICU after the introduction of public reporting was associated with a reduced odds of post-acute care use in post-reform year 2 (ratio of odds ratios [ORs], 0.94; 95% confidence interval [CI], 0.91-0.96) and increased odds of transfer to another acute care hospital in both post-reform years (year 1: ratio of ORs, 1.08; 95% CI, 1.01-1.16; year 2: ratio of ORs, 1.43; 95% CI, 1.33-1.53). There were no significant differences in in-hospital or 30-day mortality.

CONCLUSIONS

Public reporting of ICU in-hospital mortality rates was associated with changes in discharge patterns but no change in risk-adjusted mortality.

Semiquantitative cough strength score for predicting reintubation after planned extubation

BACKGROUND

Semiquantitative cough strength score (SCSS, graded 0-5) and cough peak flow (CPF) have been used to predict extubation outcome in patients in whom extubation is planned; however, the correlation of the 2 assessments is unclear.

METHODS

In the intensive care unit of a university-affiliated hospital, 186 patients who were ready for extubation after a successful spontaneous breathing trial were enrolled in the study. Both SCSS and CPF were assessed before extubation. Reintubation was recorded 72 hours after extubation.

RESULTS

Reintubation rate was 15.1% within 72 hours after planned extubation. Patients in whom extubation was successful had higher SCSSs than did reintubated patients (mean [SD], 3.2 [1.6] vs 2.2 [1.6], P = .002) and CPF (74.3 [40.0] vs 51.7 [29.4] L/min, P = .005). The SCSS showed a positive correlation with CPF (r = 0.69, P < .001). Mean CPFs were 38.36 L/min, 39.51 L/min, 44.67 L/min, 57.54 L/min, 78.96 L/min, and 113.69 L/min in patients with SCSSs of 0, 1, 2, 3, 4, and 5, respectively. The discriminatory power for reintubation, evidenced by area under the receiver operating characteristic curve, was similar: 0.677 for SCSS and 0.678 for CPF (P = .97). As SCSS increased (from 0 to 1 to 2 to 3 to 4 to 5), the reintubation rate decreased (from 29.4% to 25.0% to 19.4% to 16.1% to 13.2% to 4.1%).

CONCLUSIONS

SCSS was convenient to measure at the bedside. It was positively correlated with CPF and had the same accuracy for predicting reintubation after planned extubation.

Application of Mechanical Ventilation Weaning Predictors After Elective Cardiac Surgery

OBJECTIVE

To test several weaning predictors as determinants of successful extubation after elective cardiac surgery.

METHODS

The study was conducted at a tertiary hospital with 100 adult patients undergoing elective cardiac surgery from September to December 2014. We recorded demographic, clinical and surgical data, plus the following predictive indexes: static compliance (Cstat), tidal volume (Vt), respiratory rate (f), f/ Vt ratio, arterial partial oxygen pressure to fraction of inspired oxygen ratio (PaO2/FiO2), and the integrative weaning index (IWI). Extubation was considered successful when there was no need for reintubation within 48 hours. Sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), and negative likelihood ratio (LR-) were used to evaluate each index.

RESULTS

The majority of the patients were male (60%), with mean age of 55.4±14.9 years and low risk of death (62%), according to InsCor. All of the patients were successfully extubated. Tobin Index presented the highest SE (0.99) and LR+ (0.99), followed by IWI (SE=0.98; LR+ =0.98). Other scores, such as SP, NPV and LR-were nullified due to lack of extubation failure.

CONCLUSION

All of the weaning predictors tested in this sample of patients submitted to elective cardiac surgery showed high sensitivity, highlighting f/Vt and IWI.

Modified rapid shallow breathing index adjusted with anthropometric parameters increases predictive power for extubation failure compared with the unmodified index in postcardiac surgery patients

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.