Prevalence of myocardial ischemia during mechanical ventilation and weaning and its effects on weaning success

Exploring the Experience of Patients Who Received Mechanical Ventilation Support during Their Intensive Care Unit Stay

OBJECTIVE

The objective of this study is to explore the experiences of patients who received mechanical ventilation (MV) support during their intensive care unit (ICU) stay in Jordan.

METHODS

A phenomenological hermeneutic approach was conducted, informed by the philosophy of Martin Heidegger. Fifteen patients participated in interviews regarding their experiences during their time in the critical care unit of three public hospitals in Jordan. Interpretive Phenomenological Analysis (IPA) was used to analyse the data.

FINDINGS

The findings of the current study indicated that patients who received MV support during their ICU stays experienced both physical and psychological suffering. A pattern of shared experiences among intensive care patients was identified. Five main themes captured the patients' experiences: (1) feeling powerless, (2) being unable to recognise time, (3) feeling dead, (4) experiencing physical pain, and (5) having future concerns.

CONCLUSION

The current study found that mechanically ventilated ICU patients suffer both physically and psychologically. Nurses should use specific strategies to relieve discomfort in addition to pain treatment. This is especially essential for non-verbal patients, whose actions may resemble those of their clinicians in pain.

Occurrence of Dysrhythmias During Ventilatory Weaning and Its Association With Length of Mechanical Ventilation and In-hospital Complications

BACKGROUND

The occurrence of cardiac dysrhythmias during ventilatory weaning and its impact on the length of ventilation and occurrence of complications have not been systematically investigated.

OBJECTIVES

The aim of this study was to evaluate the association between cardiac dysrhythmias during weaning and the duration of ventilation and complications during ventilator weaning.

METHOD

Data on the length of ventilation and complications were collected from the medical records of 30 mechanically ventilated patients. Continuous electrocardiographic recordings were collected at baseline and during the initial weaning trial. Multiple regression analysis was used to evaluate the association between dysrhythmias and length of ventilation. The relationship between prolonged ventilation and complications was assessed using the χ2 analysis.

RESULTS

Supraventricular ectopic beats during weaning positively predicted the length of ventilation (P < .01). Prolonged ventilation (>7 days) is associated with the occurrence of renal insufficiency and septicemia.

CONCLUSION

The association between the occurrence of supraventricular ectopic beats during ventilator weaning and the length of ventilation requires further evaluation and tailored management to improve patient outcomes.

The Value of Ischemic Cardiac Biomarkers to Predict Spontaneous Breathing Trial or Extubation Failure: A Systematic Review

Background: It is unclear whether other cardiac biomarkers than NT-proBNP can be useful in the risk stratification of patients weaning from mechanical ventilation. The aim of this study is to summarize the role of ischemic cardiac biomarkers in predicting spontaneous breathing trial (SBT) or extubation failure. Methods: We systematically searched Embase, MEDLINE, Web of Science, and Cochrane Central for studies published before January 2024 that reported the association between ischemic cardiac biomarkers and SBT or extubation failure. Data were extracted using a standardized form and methodological assessment was performed using the QUIPS tool. Results: Seven observational studies investigating four ischemic cardiac biomarkers (Troponin-T, Troponin-I, CK-MB, Myoglobin) were included. One study reported a higher peak Troponin-I in patients with extubation failure compared to extubation success (50 ng/L [IQR, 20-215] versus 30 ng/L [IQR, 10-86], p = 0.01). A second study found that Troponin-I measured before the SBT was higher in patients with SBT failure in comparison to patients with SBT success (100 ± 80 ng/L versus 70 ± 130 ng/L, p = 0.03). A third study reported a higher CK-MB measured at the end of the SBT in patients with weaning failure (SBT or extubation failure) in comparison to weaning success (8.77 ± 20.5 ng/mL versus 1.52 ± 1.42 ng/mL, p = 0.047). Troponin-T and Myoglobin as well as Troponin-I and CK-MB measured at other time points were not found to be related to SBT or extubation failure. However, most studies were underpowered and with high risk of bias. Conclusions: The association with SBT or extubation failure is limited for Troponin-I and CK-MB and appears absent for Troponin-T and Myoglobin, but available studies are hampered by significant methodological drawbacks. To more definitively determine the role of ischemic cardiac biomarkers, future studies should prioritize larger sample sizes, including patients at risk of cardiac disease, using stringent SBTs and structured timing of laboratory measurements before and after SBT.

Relation of Ischemic Heart Disease to Outcomes in Patients With Acute Respiratory Distress Syndrome

Patients with ischemic heart disease (IHD) are often excluded from acute respiratory distress syndrome (ARDS) clinical trials. As a result, little is known about the impact of IHD in this population. We sought to assess the association between IHD and clinical outcomes in patients with ARDS. Participants from 4 ARDS randomized controlled trials with shared study criteria, definitions, and end points were included. Using multivariable logistic regression, we assessed for the association between IHD and a primary outcome of 60-day mortality. Secondary outcomes included 90-day mortality, 28-day ventilator-free days, and 28-day organ failure. Among 1,909 patients, 102 had a history of IHD (5.4%). Patients with IHD were more likely to be older and male (p <0.05). Noncardiac co-morbidities, severity of illness, and other markers of ARDS severity were not statistically different (all, p >0.05). Patients with IHD had a higher 60-day (39.2% vs 23.3%, p <0.001) and 90-day (40.2% vs 24.0%, p <0.001) mortality, and experienced more frequent renal (45.1% vs 32.0%, p = 0.006) and hepatic (35.3% vs 25.2%, p = 0.023) failure. After multivariable adjustment, 60-day (odds ratio [OR] 1.76; 95% confidence interval [CI]: 1.07 to 2.89, p = 0.025) and 90-day (OR 1.74; 95% CI: 1.06 to 2.85, p = 0.028) mortality remained higher. IHD was associated with 10% fewer ventilator-free days (incidence rate ratio 0.90; 95% CI: 0.85 to 0.96, p = 0.001). In conclusion, co-morbid IHD was associated with higher mortality and fewer ventilator-free days in patients with ARDS. Future studies are needed to identify predictors of mortality and improve treatment paradigms in this critically ill subgroup of patients.

Pooled Analysis of Central Venous Pressure and Brain Natriuretic Peptide Levels in Patients With Extubation Failure

Purpose: Cardiac insufficiency has been considered to be a common cause of extubation failure. Some studies have shown that central venous pressure (CVP) and brain natriuretic peptide (BNP) are able to predict extubation outcomes. Therefore, we conducted a pooled analysis to evaluate the potential of CVP and BNP levels as predictors of extubation outcomes, using a cohort of critically ill patients who were on mechanical ventilation (MV).

Methods: We searched three online electronic databases up to October 2021. All data were analyzed using Review Manager 5.4. For each study, the analysis was performed using standardized mean differences (SMD) with 95% confidence intervals (CI).

Results: The pooled analysis of seven studies on CVP levels and extubation outcomes showed that elevated CVP levels were significantly associated with extubation failure (SMD:0.47, 95% CI: 0. 43–0.51, p < 0.00001). This association also appeared before extubation (SMD:0.47, 95% CI: 0. 43–0.51, p < 0.00001), but it did not appear after extubation (SMD: 0.63, 95% CI: −0.05–1.31, p=0.07). Similarly, pooled analysis of eight studies on BNP levels and extubation outcomes showed that increased BNP levels are closely related to extubation failure (SMD:0.68, 95% CI: 0.49–0.86, p < 0.00001). This relationship also occurs before (SMD: 0.57, 95% CI: 0.35–0.79, p < 0.00001) and after (SMD: 0.91, 95% CI: 0.59–1.23, p < 0.00001) extubation.

Conclusions: This study showed that elevated CVP and BNP levels are associated with extubation failure in critically ill patients. However, BNP levels are more valuable than CVP levels in predicting extubation outcomes.

Diastolic dysfunction of the left ventricle - a practical approach for an anaesthetist

Bedside point-of-care echocardiography is being increasingly incorporated in peri-operative assessment and in intensive care units. Because of availability of tissue Doppler imaging in the modern ultrasound machines there has been an increased interest in research of diastolic function of left ventricle. The diastolic function is crucial for the hemodynamically effective function of the heart. Diastolic dysfunction is a well-established risk factor of the major adverse cardiac events during perioperative period, complications during weaning from ventilator and prognostic factor of mortality in septic shock.

Myocardial ischemia during ventilator weaning: a prospective multicenter cohort study

BACKGROUND

Weaning-induced cardiac pulmonary edema (WiPO) is one of the main mechanisms of weaning failure during mechanical ventilation. We hypothesized that weaning-induced cardiac ischemia (WiCI) may contribute to weaning failure from cardiac origin.

METHODS

A prospective cohort study of patients mechanically ventilated for at least 24 h who failed a first spontaneous breathing trial (SBT) was conducted in four intensive care units. Patients were explored during a second SBT using multiple tools (echocardiography, continuous 12-lead ST monitoring, biomarkers) to scrutinize the mechanisms of weaning failure. WiPO definition was based on three criteria (echocardiographic signs of increased left atrial pressure, increase in B-type natriuretic peptides, or increase in protein concentration during SBT) according to a conservative definition (at least two criteria) and a liberal definition (at least one criterion). WiCI was diagnosed according to the third universal definition of myocardial infarction proposed by the European Society of Cardiology (ESC) and the American Heart Association (AHA) statement for exercise testing.

RESULTS

Among patients who failed a first SBT, WiPO occurred in 124/208 (59.6%) and 44/208 (21.2%) patients, according to the liberal and conservative definition, respectively. Among patients with ST monitoring, WiCI was diagnosed in 36/177 (20.3%) and 12/177 (6.8%) of them, according to the ESC and AHA definitions, respectively. WiCI was not associated with WiPO and was not associated with weaning outcomes. Only two patients of the cohort were treated for an acute coronary syndrome after the second SBT, and seven other patients required coronary angiography during the weaning period.

CONCLUSIONS

This observational study showed the common occurrence of pulmonary edema in mechanically ventilated patients who failed a first SBT, but the association with cardiac ischemia and weaning outcomes was weak.

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.

Heart rate variability as a predictor of cardiac dysrhythmias during weaning from mechanical ventilation

BACKGROUND

Weaning from mechanical ventilation to spontaneous breathing is associated with changes in the hemodynamic and autonomic nervous systems that are reflected by heart rate variability. Although cardiac dysrhythmias are an important manifestation of hemodynamic alterations, the impact of heart rate variability on the occurrence of dysrhythmias during weaning has not been specifically studied.

OBJECTIVES

To describe differences in heart rate variability spectral power and occurrence of cardiac dysrhythmias at baseline and during the initial trial of weaning from mechanical ventilation and to evaluate the impact of heart rate variability during weaning on occurrence of dysrhythmias.

METHOD

Continuous 3-lead electrocardiographic recordings were collected from 35 patients receiving mechanical ventilation for 24 hours at baseline and during the initial weaning trial. Heart rate variability was evaluated by using spectral power analysis.

RESULTS

Low-frequency power increased (P = .04) and high-frequency and very-low-frequency power did not change during weaning. The mean number of supraventricular ectopic beats per hour during weaning was higher than the mean at baseline (P < .001); the mean of ventricular ectopic beats did not change. Low-frequency power was a predictor of ventricular and supraventricular ectopic beats during weaning (P < .001). High-frequency power was predictive of ventricular and supraventricular (P = .02) ectopic beats during weaning. Very-low-frequency power was predictive of ventricular ectopic beats (P < .001) only.

CONCLUSION

Heart rate variability power spectra during weaning were predictive of dysrhythmias.

Ventilator management in the cardiac intensive care unit

Patients admitted to the Cardiac Intensive Care Unit (CICU) are of increasing complexity and often require ventilatory support. A deep understanding of respiratory physiology and the interactions between the cardiovascular and respiratory systems is essential. Ventilatory support should be tailored to the specific patient condition, ensuring effective minute ventilation, reducing work of breathing and minimizing adverse hemodynamic effects. The weaning process can stress the cardiovascular system and cardiac failure is a common cause of failure to wean. Identification of patients likely to fail and prompt pre-emptive intervention is crucial for successful weaning and avoiding complications related to prolonged mechanical ventilation.

N-terminal prohormone B-type natriuretic peptide and weaning outcome in postoperative patients with pulmonary complications

Objective

To evaluate the relationship between plasma N-terminal prohormone B-type natriuretic peptide (NT-proBNP) and weaning outcomes, and the ability of NT-proBNP level to predict weaning success, in cancer patients with pulmonary complications undergoing noncardiac major surgeries.

Methods

Patients who were mechanically ventilated following postoperative respiratory failure were enrolled. NT-proBNP levels at the end of a 2-h spontaneous breathing trial were measured. Weaning was considered a success in patients who completed the trial and maintained spontaneous breathing following extubation for >48 h.

Results

Out of 29 patients, 22 patients weaned successfully but weaning failed in 7 patients. Plasma NT-proBNP was significantly higher in the weaning failure group than in the weaning success group. For predicting weaning success, the optimal NT-proBNP threshold value at the end of the spontaneous breathing trial was <448 ng/l (receiver operating characteristic analysis; sensitivity 68.18%, specificity 85.71%, positive predictive value 93.7% and negative predictive value 46.2%).

Conclusion

Measuring NT-proBNP at the end of a spontaneous breathing trial may assist in predicting weaning success, as a noninvasive, quantitative and repeatable indicator of cardiac stress in patients with postsurgical respiratory failure.

Cardiac ischemia in patients with septic shock randomized to vasopressin or norepinephrine

Introduction

Cardiac troponins are sensitive and specific biomarkers of myocardial necrosis. We evaluated troponin, CK, and ECG abnormalities in patients with septic shock and compared the effect of vasopressin (VP) versus norepinephrine (NE) on troponin, CK, and ECGs.

Methods

This was a prospective substudy of a randomized trial. Adults with septic shock randomly received, blinded, a low-dose infusion of VP (0.01 to 0.03 U/min) or NE (5 to 15 μg/min) in addition to open-label vasopressors, titrated to maintain a mean blood pressure of 65 to 75 mm Hg. Troponin I/T, CK, and CK-MB were measured, and 12-lead ECGs were recorded before study drug, and 6 hours, 2 days, and 4 days after study-drug initiation. Two physician readers, blinded to patient data and drug, independently interpreted ECGs.

Results

We enrolled 121 patients (median age, 63.9 years (interquartile range (IQR), 51.1 to 75.3), mean APACHE II 28.6 (SD 7.7)): 65 in the VP group and 56 in the NE group. At the four time points, 26%, 36%, 32%, and 21% of patients had troponin elevations, respectively. Baseline characteristics and outcomes were similar between patients with positive versus negative troponin levels. Troponin and CK levels and rates of ischemic ECG changes were similar in the VP and the NE groups. In multivariable analysis, only APACHE II was associated with 28-day mortality (OR, 1.07; 95% CI, 1.01 to 1.14; P = 0.033).

Conclusions

Troponin elevation is common in adults with septic shock. We observed no significant differences in troponin, CK, and ECGs in patients treated with vasopressin and norepinephrine. Troponin elevation was not an independent predictor of mortality.

Trial registration

Controlled-trials.com ISRCTN94845869

Agreement in electrocardiogram interpretation in patients with septic shock

OBJECTIVE

The reliability of electrocardiogram interpretation to diagnose myocardial ischemia in critically ill patients is unclear. In adults with septic shock, we assessed intra- and inter-rater agreement of electrocardiogram interpretation, and the effect of knowledge of troponin values on these interpretations.

DESIGN

Prospective substudy of a randomized trial of vasopressin vs. norepinephrine in septic shock.

SETTING

Nine Canadian intensive care units.

PATIENTS

Adults with septic shock requiring at least 5 μg/min of norepinephrine for 6 hrs.

INTERVENTIONS

Twelve-lead electrocardiograms were recorded before study drug, and 6 hrs, 2 days, and 4 days after study drug initiation.

MEASUREMENTS

Two physician readers, blinded to patient data and group, independently interpreted electrocardiograms on three occasions (first two readings were blinded to patient data; third reading was unblinded to troponin). To calibrate and refine definitions, both readers initially reviewed 25 trial electrocardiograms representing normal to abnormal. Cohen's Kappa and the φ statistic were used to analyze intra- and inter-rater agreement.

RESULTS

One hundred twenty-one patients (62.2 ± 16.5 yrs, Acute Physiology and Chronic Health Evaluation II 28.6 ± 7.7) had 373 electrocardiograms. Blinded to troponin, readers 1 and 2 interpreted 46.4% and 30.0% of electrocardiograms as normal, and 15.3% and 12.3% as ischemic, respectively. Intrarater agreement was moderate for overall ischemia (κ 0.54 and 0.58), moderate/good for "normal" (κ 0.69 and 0.55), fair to good for specific signs of ischemia (ST elevation, T inversion, and Q waves, reader 1 κ 0.40 to 0.69; reader 2 κ 0.56 to 0.70); and good/very good for atrial arrhythmias (κ 0.84 and 0.79) and bundle branch block (κ 0.88 and 0.79). Inter-rater agreement was fair for ischemia (κ 0.29), moderate for ST elevation (κ 0.48), T inversion (κ 0.52), and Q waves (κ 0.44), good for bundle branch block (κ 0.78), and very good for atrial arrhythmias (κ 0.83). Inter-rater agreement for ischemia improved from fair to moderate (κ 0.52, p = .028) when unblinded to troponin.

CONCLUSIONS

In patients with septic shock, inter-rater agreement of electrocardiogram interpretation for myocardial ischemia was fair, and improved with troponin knowledge.

New insights into weaning from mechanical ventilation: left ventricular diastolic dysfunction is a key player

PURPOSE

To investigate the diagnostic performance of Doppler echocardiography (DE) in predicting the outcome of weaning from mechanical ventilation in patients without overt cardiac disease.

METHODS

Fifty critical care noncardiac patients who fulfilled predetermined criteria for weaning underwent DE before and at the end of spontaneous breathing trial (pre-SBT/end-SBT, respectively). "Conventional" mitral inflow analysis and "advanced" DE parameters [tissue Doppler imaging (TDI)-derived mitral/tricuspid annular velocities and color M-mode Doppler velocity of propagation (V p)] were used to assess left ventricular (LV) diastolic function/filling pressures. Weaning was considered successful if patients had been extubated after successful SBT and sustained spontaneous breathing for more than 48 h.

RESULTS

Twenty-eight patients (56%) failed weaning: 23 patients failed SBT and 5 required reintubation within 48 h. Weaning failure was associated with the degree of LV diastolic dysfunction at pre-SBT (P = 0.01). Patients who failed weaning presented evidence of increased LV filling pressures at pre-SBT, by demonstrating increased E/E m and E/V p ratios compared with patients with successful outcome (P ≤ 0.004); pre-SBT values of lateral E/E m greater than 7.8 and E/V p greater than 1.51 predicted weaning failure with an area under the curve, sensitivity (%), and specificity (%) of 0.86, 79, and 100, and 0.74, 75, and 73, respectively. Lateral E/E m was the only factor independently associated with weaning failure before SBT; OR (95% CI) 5.62 (1.17-26.96), P = 0.03.

CONCLUSIONS

Our findings suggest that LV diastolic dysfunction is significantly associated with weaning outcome in critically ill patients with preserved LV systolic function. An E/E m ratio greater than 7.8 may identify patients at high risk of weaning failure.

Continuous ST-segment monitoring in the intensive care unit

This article provides evidence-based rationales to substantiate revisions of current monitoring practices and to provide realistic strategies for implementation of new practices.

Echocardiographic evaluation during weaning from mechanical ventilation

INTRODUCTION

Echocardiographic, electrocardiographic and other cardiorespiratory variables can change during weaning from mechanical ventilation.

OBJECTIVES

To analyze changes in cardiac function, using Doppler echocardiogram, in critical patients during weaning from mechanical ventilation, using two different weaning methods: pressure support ventilation and T-tube; and comparing patient subgroups: success vs. failure in weaning.

METHODS

Randomized crossover clinical trial including patients under mechanical ventilation for more than 48 h and considered ready for weaning. Cardiorespiratory variables, oxygenation, electrocardiogram and Doppler echocardiogram findings were analyzed at baseline and after 30 min in pressure support ventilation and T-tube. Pressure support ventilation vs. T-tube and weaning success vs. failure were compared using ANOVA and Student's t-test. The level of significance was p<0.05.

RESULTS

Twenty-four adult patients were evaluated. Seven patients failed at the first weaning attempt. No echocardiographic or electrocardiographic differences were observed between pressure support ventilation and T-tube. Weaning failure patients presented increases in left atrium, intraventricular septum thickness, posterior wall thickness and diameter of left ventricle and shorter isovolumetric relaxation time. Successfully weaned patients had higher levels of oxygenation.

CONCLUSION

No differences were observed between Doppler echocardiographic variables and electrocardiographic and other cardiorespiratory variables during pressure support ventilation and T-tube. However cardiac structures were smaller, isovolumetric relaxation time was larger, and oxygenation level was greater in successfully weaned patients.

Clinical review: liberation from mechanical ventilation

Mechanical ventilation is the defining event of intensive care unit (ICU) management. Although it is a life saving intervention in patients with acute respiratory failure and other disease entities, a major goal of critical care clinicians should be to liberate patients from mechanical ventilation as early as possible to avoid the multitude of complications and risks associated with prolonged unnecessary mechanical ventilation, including ventilator induced lung injury, ventilator associated pneumonia, increased length of ICU and hospital stay, and increased cost of care delivery. This review highlights the recent developments in assessing and testing for readiness of liberation from mechanical ventilation, the etiology of weaning failure, the value of weaning protocols, and a simple practical approach for liberation from mechanical ventilation.

Autonomic tone in medical intensive care patients receiving mechanical ventilation and during a CPAP weaning trial

Mechanical ventilator support and the resumption of spontaneous ventilation or weaning create significant alterations in alveolar and intrathoracic pressure that influence thoracic blood volume and flow. Compensatory autonomic tone alterations occur to ensure adequate tissue oxygen delivery, but autonomic responses may produce cardiovascular dysfunction with subsequent weaning failure. The authors describe autonomic responses of critically ill patients (n = 43) during a 24-hr period of mechanical ventilatory support and during the 24 hr that included their initial spontaneous breathing trial using continuous positive airway pressure. Nearly two thirds of these patients demonstrated abnormal autonomic function and this dysfunction was more severe in those patients who were unable to sustain spontaneous ventilation (n = 15). With further systematic study, autonomic responses may be useful in the identification of patients who are likely to develop cardiac dysfunction with the resumption of spontaneous breathing.

Cardiovascular effects of mechanical ventilation and weaning

Because of their anatomic position in the closed thoracic cavity, the heart and lungs interact during each ventilation cycle. The application of mechanical ventilation and subsequent removal changes normal ventilatory mechanics and produces alterations in cardiac preload and afterload that influence global hemodynamic state and delivery of oxygen and nutrients. Adverse cardiovascular responses to mechanical ventilation and weaning from ventilation include hemodynamic alterations and instability, myocardial ischemia, autonomic dysfunction, and cardiac dysrhythmias. Clinicians must have a clear understanding of the cardiovascular effects of mechanical ventilation and weaning so they may anticipate, recognize, and effectively manage negative effects and improve patient outcomes.

Liberation from mechanical ventilation: what monitoring matters?

Over the past 2 decades, the art of "weaning" from mechanical ventilation has been informed by increasing published basic science and outcomes studies. Although monitoring technologies can provide vast amounts of information before, during, and after liberation from mechanical ventilation, little data exists on how to maximally harness even routinely monitored, basic physiologic parameters. Overdependence on technology and derived variables, without data to demonstrate benefit, may even inhibit the patient's progress if it is used inappropriately. We review the scientific evidence for best using routinely available physiologic data and a few more sophisticated and invasive monitoring technologies during weaning. We also suggest future study designs that would better inform the process of liberation from the ventilator and endotracheal extubation.

Extubation failure in intensive care unit: Predictors and management

Extubation failure-need for reintubation within 72 h of extubation, is common in intensive care unit (ICU). It can cause increased morbidity, higher costs, higher ICU and hospital length of stay (LOS) and mortality. Patients with advanced age, high severity of illness at ICU admission and extubation, preexisting chronic respiratory and cardiovascular disorders are at increased risk of extubation failure. Unresolved illness, development and progression of organ failure during the time from extubation to reintubation and reintubation itself have been proposed as reasons for increased morbidity and mortality. Parameters used to predict extubation failure can be categorized into parameters assessing respiratory mechanics, airway patency and protection and cardiovascular reserve. Adequate cough strength, minimal secretions and alertness are necessary for successful extubation. Evidence suggests that early institution of non-invasive ventilation and prophylactic administration of methylprednisolone may prevent reintubation in some patients. The intensivist needs to identify patients at high risk of extubation failure and be prepared to reinstitute ventilation early to prevent adverse outcomes.