27th
April 2009
Supervisied by :Dr 楊煦星
Presented by : R2 蔡為民
本檔僅供內部教學使用
檔案內所使用之照片之版權仍屬於原期刊
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Introduction
Readiness testing
Spontaneous breathing trials
Causes of weaning failure
Progressive withdrawal
Weaning protocols
Extubation
Weaning from prolonged
mechanical ventilation
Conclusion
Invasive mechanical ventilationInvasive mechanical ventilation is associated with risks and
complications that prolong the...
A multisociety consensus conference characterized
the weaning process as a continuum lasting from
intubation until hospita...
A minority of patients fail and may need a more
gradual approach, with success ultimately dependent on
Identifying correct...
Readiness
Testing
Recognizing that respiratory failure
and respiratory muscle function have
improved and the patient is ca...
Approximately 1/31/3 of patients fall into the difficult anddifficult and
prolonged categoriesprolonged categories and exp...
The patient’s capacity to breathe spontaneouslycapacity to breathe spontaneously is often
underestimatedunderestimated.
Fo...
A comprehensive evidence-based medicine review
identified more than 50 objective physiologic tests50 objective physiologic...
Weaning predictors
(1) Negative inspiratory force (maximal
inspiratory pressure).
(2) Minute ventilation.
(3) Respiratory ...
Frequency–tidal volume ratio ( f/VT)
How the measurements are made ?
Effect of pressure support ventilation and positive e...
Frequency–tidal volume ratio ( f/VT)
The average sensitivity of 0.87 indicates that f/VT is a reliable
screening test for ...
Whether the f/VT, or any weaning predictor, actually
facilitates weaning decision-making ?
A randomized, controlled trial ...
Whether the f/VT, or any weaning predictor, actually
facilitates weaning decision-making ?
A randomized, controlled trial ...
Am J Respir Crit
Care Med 1999; 159:439–446.
One explanation is the demonstrated safety of a closely
monitored SBT.
Am J Respir Crit Care Med 2003;
167:120–127.
In conclusion, in contrast to our hypothesis, weaning failure
was not accompa...
Thus a failed SBTfailed SBT should not result in respiratory muscle injury
as long as patients are quickly reconnected to ...
Efficacy and safety of a paired sedation and ventilator weaning protocol for
mechanically ventilated patients in intensive...
Weaning from mechanical ventilation: a model for extubation.
Intensive Care Med 1999; 25:1077–1083.
Zeggwagh AA, Abouqal R...
Theoretically, PSV more effectively counterbalancesPSV more effectively counterbalances
endotracheal tube-related resistiv...
Extubation after breathing trials with automatic tube compensation, T-tube, or pressure
support ventilation.
Acta Anaesthe...
Extubation outcome following a spontaneous breathing trial with automatic tube
compensation versus continuous positive air...
Weaning from mechanical ventilation with pressure support in patients failing a T-tube
trial of spontaneous breathing.
Int...
Optimal SBT duration
In two studies suggesting that 30 min is equivalent to 120 min30 min is equivalent to 120 min
with ei...
Optimal SBT duration
Comparison of two methods for weaning patients with chronic obstructive pulmonary
disease requiring m...
Imbalance between respiratory load and capacityrespiratory load and capacity (e.g.
diaphragmatic strength and endurance)
E...
An important component of load/capacity imbalanceload/capacity imbalance is
reduced respiratory muscle strengthreduced res...
Cardiac dysfunctionCardiac dysfunction contributes to weaning failure especially in
patients with coronary artery disease ...
 The stress of weaningstress of weaning is considerable as it results in
increased levels of plasma insulin, cortisol, an...
How long should the patient rest after a failed
weaning effort?
When clinical evidence of respiratory muscle fatigue is ab...
The clinician must decide whether to perform daily SBTs or
whether to more gradually reduce ventilatory support (progressi...
Two RCTs compared progressive withdrawal techniquesprogressive withdrawal techniques
in patients satisfying readiness crit...
A more recent investigation randomized patients to SBTs
(120 min) with T-piece or PSVPSV and found the latter
associated w...
Noninvasive ventilation (NIV)
Three published RCTsThree published RCTs have explored the use of noninvasive ventilation
(N...
Can the weaning process be automated?
A multicenter randomized trial of computer-driven protocolized weaning from
mechanic...
The computer-driven ventilator continuously monitors
physiologic parameters
 Respiratory rate
Tidal volume
 PetCO2
Adju...
In certain settings, uncontrolled investigations and RCTs
demonstrate improved outcome with protocol-driven weaningprotoco...
Observational and randomized trials demonstrate that
protocols directed at minimizing the use of sedativeminimizing the us...
Between 25 and 40%25 and 40% of patients develop signs of
respiratory distressrespiratory distress after extubation
Decisi...
Implications of extubation delay in brain-injured patients meeting standard weaning
criteria.
Am J Respir Crit Care Med 20...
Risk factors for extubation failure in patients following a successful spontaneous
breathing trial.
Chest 2006; 130:1664–1...
One promising technique has demonstrated that risk of
extubation failure is associated with greater time needed togreater ...
Respiratory failure in chronic obstructive pulmonary disease after extubation: value of
expiratory flow limitation and air...
Extubation failure often results from inability to protectinability to protect
the airwaythe airway and manage respiratory...
Intravenous injection of methylprednisolone reduces the incidence of postextubation
stridor in intensive care unit patient...
The ability to protect the airway is also dependent upon
cough strengthcough strength and volume of respiratory secretions...
Neurologic status, cough, secretions and extubation outcomes.
Intensive Care Med 2004; 30:1334–1339.
Salam A, Tilluckdharr...
10% ~ 20%10% ~ 20% of patients with acute respiratory failure
require 21 or more days21 or more days of ventilatory suppor...
WeaningWeaning efforts should start as soon as possiblestart as soon as possible after transfer
as 10–30% of patients10–30...
• Determining readiness is best achieved using
liberal oxygenation criteria
• Does not require routine use of weaning
pred...
• SBTs should last at least 30 min and can be
conducted on low levels of pressure support,
CPAP, or T-piece.
• Weaning fai...
• Randomized trials suggest that NIV (in patients
with COPD) and computer-driven approaches
show promise as weaning strate...
27th April 2009 Supervisied by :Dr 楊煦星
27th April 2009 Supervisied by :Dr 楊煦星
27th April 2009 Supervisied by :Dr 楊煦星
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27th April 2009 Supervisied by :Dr 楊煦星

  1. 1. 27th April 2009 Supervisied by :Dr 楊煦星 Presented by : R2 蔡為民 本檔僅供內部教學使用 檔案內所使用之照片之版權仍屬於原期刊 公開使用時 , 須獲得原期刊之同意授權
  2. 2. Introduction Readiness testing Spontaneous breathing trials Causes of weaning failure Progressive withdrawal
  3. 3. Weaning protocols Extubation Weaning from prolonged mechanical ventilation Conclusion
  4. 4. Invasive mechanical ventilationInvasive mechanical ventilation is associated with risks and complications that prolong the duration of mechanicalprolong the duration of mechanical ventilation and increase the risk for deathventilation and increase the risk for death Increasing duration of mechanical ventilationIncreasing duration of mechanical ventilation itself is associated with increased mortalityincreased mortality Epstein S. Complications in ventilator supported patients. In: Tobin M, editor.Principles and practice of mechanical ventilation, 2nd ed. New York:McGraw Hill; 2006. pp. 877–902. Esteban A, Anzueto A, Frutos F, et al. Characteristics and outcomes in adultpatients receiving mechanical ventilation: a 28- day international study. J AmMed Assoc 2002; 287:345–355
  5. 5. A multisociety consensus conference characterized the weaning process as a continuum lasting from intubation until hospital discharge Weaning from mechanical ventilation. EurRespir J 2007; 29:1033–1056. Recommendation of an international, multisociety consensus conference onweaning. Boles JM, Bion J, Connors A, et al.
  6. 6. A minority of patients fail and may need a more gradual approach, with success ultimately dependent on Identifying correctable causes for weaning intolerance. Once spontaneous breathing is tolerated attention shifts to determining whether the patient can be extubated
  7. 7. Readiness Testing Recognizing that respiratory failure and respiratory muscle function have improved and the patient is capable of spontaneous breathing Simple weaning Difficult weaning Prolonged weaning Patient tolerates first spontaneous breathing trial (SBT)tolerates first spontaneous breathing trial (SBT) and is successfully extubated (70% of all patients). Patient fails to tolerate initial SBTfails to tolerate initial SBT, successful weaning requiring up to three SBTs or up to 7 days from first SBTthree SBTs or up to 7 days from first SBT. Patient fails at least three SBTs or takes more than 7 daysfails at least three SBTs or takes more than 7 days after the first SBT.after the first SBT.
  8. 8. Approximately 1/31/3 of patients fall into the difficult anddifficult and prolonged categoriesprolonged categories and experience higher ICU mortalityhigher ICU mortality (25%)(25%) than seen with simple weaning (5%). The higher mortality  Complications of mechanical ventilation  Underlying illness leading to mechanical ventilation.
  9. 9. The patient’s capacity to breathe spontaneouslycapacity to breathe spontaneously is often underestimatedunderestimated. For example, 50%50% of patients who self-extubateself-extubate do not require reintubation Patient-initiated device removal in intensive care units: a national prevalence study. Crit Care Med 2007; 35:2714–2720. Mion LC, Minnick AF, Leipzig R, et al. 30%30% of patients never satisfying objective readinessnever satisfying objective readiness criteriacriteria can still be successfully weanedsuccessfully weaned The prognostic significance of passing adaily screen of weaning parameters. Intensive Care Med 1999; 25: 581–587 Ely EW, Baker AM, Evans GW, et al.
  10. 10. A comprehensive evidence-based medicine review identified more than 50 objective physiologic tests50 objective physiologic tests (weaning predictors) as tools for assessing readiness for spontaneousassessing readiness for spontaneous breathing.breathing. Only five were associated with clinically significantOnly five were associated with clinically significant changes in the probability of weaning success or failurechanges in the probability of weaning success or failure but predictive capacity was modest •Epstein SK. Weaning parameters. Respir Care Clin N Am 2000; 6: 253–301. •MacIntyre NR, Cook DJ, Ely EW Jr, et al. Evidence-based guidelines for weaning and discontinuing ventilatory support: a collective task force facilitatedby the American College of Chest Physicians; the American Associationfor Respiratory Care; and the American College of Critical Care Medicine. Chest 2001; 120:375S– 395S. •Meade M, Guyatt G, Cook D, et al. Predicting success in weaning from mechanical ventilation. Chest 2001; 120:400S–424S.
  11. 11. Weaning predictors (1) Negative inspiratory force (maximal inspiratory pressure). (2) Minute ventilation. (3) Respiratory frequency. (4) Tidal volume. (5) Frequency–tidal volume ratio ( f/VT).(5) Frequency–tidal volume ratio ( f/VT).
  12. 12. Frequency–tidal volume ratio ( f/VT) How the measurements are made ? Effect of pressure support ventilation and positive end expiratory pressure on the rapid shallow breathing index in intensive care unit patients. Intensive Care Med 2008; 34:505–510. El-Khatib MF, Zeineldine SM, Jamaleddine GW MEASUREMENTS AND RESULTS: Respiratory frequency (f) and tidal volume (VT) were measured during PS, CPAP, CPAP-R/A, and T-piece in all patients. RSBI (f/VT) was determined for each patient under all experimental conditions, and the average RSBI was compared during PS, CPAP, CPAP-R/A, and T-piece. RSBI was significantly smaller during PS (46+/-8 bpm/l), CPAP (63+/-13 bpm/l) and CPAP- R/A (67+/-14 bpm/l) vs. T-piece (100+/-23 bpm/l).
  13. 13. Frequency–tidal volume ratio ( f/VT) The average sensitivity of 0.87 indicates that f/VT is a reliable screening test for successful weaning
  14. 14. Whether the f/VT, or any weaning predictor, actually facilitates weaning decision-making ? A randomized, controlled trial of the role of weaning predictors in clinical decision making. Crit Care Med 2006; 34:2530–2535. Tanios MA, Nevins ML, Hendra KP, et al. Interventions:Interventions: Patients were screened daily for measures of oxygenation, cough and secretions, adequate mental status, and hemodynamic stability. Patients were randomized to two groups; in one group the f/Vt was measured but not usedin one group the f/Vt was measured but not used in the decision to wean (n = 151), but in the other group, f/Vt was measured and usedin the other group, f/Vt was measured and used, using a threshold of 105 breaths/min/L (n = 153). Patients passing the screen received a 2- hr spontaneous breathing trial. Patients passing the spontaneous breathing trial were eligible for an extubation attempt.
  15. 15. Whether the f/VT, or any weaning predictor, actually facilitates weaning decision-making ? A randomized, controlled trial of the role of weaning predictors in clinical decision making. Crit Care Med 2006; 34:2530–2535. Tanios MA, Nevins ML, Hendra KP, et al. Measurements and Main ResultsMeasurements and Main Results: Groups were similar with regard to gender, age, and Acute Physiology and Chronic Health Evaluation II score. The median duration for weaning time was significantly shorter in the group where the weaning predictor was not used (2.0 vs. 3.0 days, p = .04). There was no difference with regard to the extubationThere was no difference with regard to the extubation failure, in-hospital mortality rate, tracheostomy, or unplanned extubationfailure, in-hospital mortality rate, tracheostomy, or unplanned extubation. Conclusions:Conclusions: Including a weaning predictor f/Vt) in a protocol prolonged weaning time. In addition, the predictor did not confer survival benefit or reduce the incidence of extubationthe predictor did not confer survival benefit or reduce the incidence of extubation failure or tracheostomy.failure or tracheostomy. The results of this study indicate that f/Vt should not be used routinely in weaning decision making.
  16. 16. Am J Respir Crit Care Med 1999; 159:439–446. One explanation is the demonstrated safety of a closely monitored SBT.
  17. 17. Am J Respir Crit Care Med 2003; 167:120–127. In conclusion, in contrast to our hypothesis, weaning failure was not accompanied low-frequency fatigue of thenot accompanied low-frequency fatigue of the diaphragm,diaphragm, although many weaning failure patients displayed diaphragmatic weakness.
  18. 18. Thus a failed SBTfailed SBT should not result in respiratory muscle injury as long as patients are quickly reconnected to the ventilatoras long as patients are quickly reconnected to the ventilator when signs of weaning intolerance occur. • Although unproven, structural respiratory muscle injury may occur if the failed weaning trial is improperly extended.
  19. 19. Efficacy and safety of a paired sedation and ventilator weaning protocol for mechanically ventilated patients in intensive care (awakening and breathing controlled trial): a randomised controlled trial. Lancet 2008; 371:126–134. Girard TD, Kress JP, Fuchs BD, et al. These concepts are supported by the ABC trialABC trial in which greater than 50% passed an SBT when readiness was50% passed an SBT when readiness was assessed using liberal oxygenation criteriaassessed using liberal oxygenation criteria (SpO2 88% on FiO2 0.5 and PEEP 8cmH2O) and weaning predictors were not used
  20. 20. Weaning from mechanical ventilation: a model for extubation. Intensive Care Med 1999; 25:1077–1083. Zeggwagh AA, Abouqal R, Madani N, et al. Direct extubationDirect extubation after satisfying readiness criteria alone is unwise, as 40% of such patients require reintubation40% of such patients require reintubation Therefore a trial of spontaneous breathing, carried out onspontaneous breathing, carried out on low-level pressure support (PSV7mmHg), CPAP, orlow-level pressure support (PSV7mmHg), CPAP, or unassisted through a T-pieceunassisted through a T-piece, is indicated. Randomized controlled trials indicate these techniques are equivalent
  21. 21. Theoretically, PSV more effectively counterbalancesPSV more effectively counterbalances endotracheal tube-related resistive workloadendotracheal tube-related resistive workload, but a given level may either overcompensate or under-compensate for imposed work
  22. 22. Extubation after breathing trials with automatic tube compensation, T-tube, or pressure support ventilation. Acta Anaesthesiol Scand 2002; 46:973–979. Haberthur C, Mols G, Elsasser S, et al. Automatic tube compensation (ATC) SBTs conducted with either ATC, PSV, or T-piece to be equivalent
  23. 23. Extubation outcome following a spontaneous breathing trial with automatic tube compensation versus continuous positive airway pressure. Crit Care Med 2006; 34:682–686. Cohen JD, Shapiro M, Grozovski E, et al. Automatic tube compensation (ATC) Higher SBT success for ATC compared to CPAP
  24. 24. Weaning from mechanical ventilation with pressure support in patients failing a T-tube trial of spontaneous breathing. Intensive Care Med 2006; 32:165–169 Ezingeard E, Diconne E, Guyomarc’h S, et al. Automatic tube compensation (ATC) Patients failing a 30- min T-tube trialfailing a 30- min T-tube trial, immediate conversion to PSV 7cmH2O for additional 30 min led to weaning success in 21 of 31PSV 7cmH2O for additional 30 min led to weaning success in 21 of 31 patients,patients, suggesting the endotracheal tube can contribute to iatrogenic weaning failure
  25. 25. Optimal SBT duration In two studies suggesting that 30 min is equivalent to 120 min30 min is equivalent to 120 min with either T-piece or PSV Optimal SBT duration may depend upon the duration of ventilation or the underlying cause for respiratory failure.
  26. 26. Optimal SBT duration Comparison of two methods for weaning patients with chronic obstructive pulmonary disease requiring mechanical ventilation for more than 15 days. Am J Respir Crit Care Med 2001; 164:225–230. Vitacca M, Vianello A, Colombo D, et al. 75 patients with chronic obstructive pulmonary disease (COPD), ventilated for 15 or more days, found a median time to trial failure of 120 min Therefore, in some patients the SBT should be extended to at least 120 min.
  27. 27. Imbalance between respiratory load and capacityrespiratory load and capacity (e.g. diaphragmatic strength and endurance) Excessive load may be imposed by the  Endotracheal tube,  Heat and moisture exchange devices,  Ventilator tubing and valves Intrinsic factors such as  Increased airways resistance,  Increased elastance from dynamic hyperinflation,  Reduced respiratory muscle capacity are more commonly responsible
  28. 28. An important component of load/capacity imbalanceload/capacity imbalance is reduced respiratory muscle strengthreduced respiratory muscle strength. Mechanisms include  Reduced diaphragmatic pressure generation secondary to dynamic hyperinflation  Phrenic nerve injury after cardiac surgery Other identified causes  Critical illness neuromyopathy  Ventilator- induced diaphragmatic dysfunction (VIDD)  Endocrinopathy (e.g. hypothyroidism, adrenal insufficiency) or malnutrition
  29. 29. Cardiac dysfunctionCardiac dysfunction contributes to weaning failure especially in patients with coronary artery disease or chronic heart failure  Myocardial ischemia (release in catecholamines)  Pulmonary edema (elevation of transmural pulmonaryartery occlusion pressure) Patients at risk for weaning failure from cardiac disease can manifest an elevated B-type natriuretic peptide (BNP) or N-terminal pro-BNP In one study, a pre-SBT BNP >275 pg/dl correlated with a longer duration of weaning
  30. 30.  The stress of weaningstress of weaning is considerable as it results in increased levels of plasma insulin, cortisol, and glucose .  Lastly, positive fluid balancepositive fluid balance has been associated with weaning failure The effects of different weaning modes on the endocrine stress response. Crit Care 2004; 8:R31–R34. Koksal GM, Sayilgan C, Sen O, et al. Fluid balance and weaning outcomes. Intensive Care Med 2005; 31:1643–1647. Upadya A, Tilluckdharry L, Muralidharan V, et al.
  31. 31. How long should the patient rest after a failed weaning effort? When clinical evidence of respiratory muscle fatigue is absent, multiple daily SBTs are well tolerated. Yet, a comparison of two international studies found declining use of this approach from 1998 to 2004declining use of this approach from 1998 to 2004 Pattern of recovery from diaphragmatic fatigue over 24 h. J Appl Physiol 1995; 79:539–546. Laghi F, D’Alfonso N, Tobin MJ. If unequivocal evidence for fatigue is evident then clinicians should consider providing 24 h of rest on full support before24 h of rest on full support before preceding with the next weaning effortpreceding with the next weaning effort
  32. 32. The clinician must decide whether to perform daily SBTs or whether to more gradually reduce ventilatory support (progressive withdrawal). Inspiratory muscle training is ineffective in mechanically ventilated critically ill patients. Clinics 2005; 60:479–484 Caruso P, Denari SD, Ruiz SA, et al. A randomized trial showed no benefit to using inspiratoryno benefit to using inspiratory muscle trainingmuscle training
  33. 33. Two RCTs compared progressive withdrawal techniquesprogressive withdrawal techniques in patients satisfying readiness criteriasatisfying readiness criteria but intolerant of aintolerant of a 2-h SBT2-h SBT Although one study found T-piece superior and the other observed PSV to be most efficient, both demonstrated that synchronized intermittent mandatory ventilationsynchronized intermittent mandatory ventilation (SIMV) alone delays the process.(SIMV) alone delays the process.
  34. 34. A more recent investigation randomized patients to SBTs (120 min) with T-piece or PSVPSV and found the latter associated with decreased weaning time, duration ofdecreased weaning time, duration of mechanical ventilation, and ICU length of staymechanical ventilation, and ICU length of stay Comparison of pressure support and T-tube weaning from mechanical ventilation: randomized prospective study. Croat Med J 2004; 45:162–166 Matic I, Majeric-Kogler V
  35. 35. Noninvasive ventilation (NIV) Three published RCTsThree published RCTs have explored the use of noninvasive ventilation (NIV) in patients having trouble weaning from mechanical ventilationhaving trouble weaning from mechanical ventilation Studies indicate that NIV can facilitate weaning in a highlyNIV can facilitate weaning in a highly select group of patients with acute on chronic lung diseaseselect group of patients with acute on chronic lung disease  SBT readiness criteria must be satisfied  Extubation criteria must be satisfied  The patient must be a good candidate for NIV (able to breathe spontaneously for at least 5–10 min and not be a difficult reintubation).
  36. 36. Can the weaning process be automated? A multicenter randomized trial of computer-driven protocolized weaning from mechanical ventilation. Am J Respir Crit Care Med 2006; 174:894–900. Lellouche F, Mancebo J, Jolliet P, et al. One multicenter study randomized 144 patients to Conventional weaningConventional weaning VS Computerized weaningComputerized weaning using a closed loop knowledge- based system
  37. 37. The computer-driven ventilator continuously monitors physiologic parameters  Respiratory rate Tidal volume  PetCO2 Adjusts pressure support by 2–4cmH2O to maintain the patient in a ‘zone of comfort’. When a minimal level of PSV is reached, a SBT is conducted and the clinician prompted if the SBT proves successful. Computer-driven ventilationComputer-driven ventilation resulted in decreased duration ofdecreased duration of weaning, total duration of ventilation, median ICU stay,weaning, total duration of ventilation, median ICU stay, without adverse event or increase in reintubation.without adverse event or increase in reintubation.
  38. 38. In certain settings, uncontrolled investigations and RCTs demonstrate improved outcome with protocol-driven weaningprotocol-driven weaning implemented by physicians or by respiratory care practitionersimplemented by physicians or by respiratory care practitioners and ICU nursesand ICU nurses Standard care VS Intervention strategy patients passing the daily screen underwent a 2-h SBT with a prompt for extubation if the trial was tolerated
  39. 39. Observational and randomized trials demonstrate that protocols directed at minimizing the use of sedativeminimizing the use of sedative infusions shorten the weaning processinfusions shorten the weaning process. Specifically, approaches intended to avoid over sedationavoid over sedation by limiting the use of continuous infusionslimiting the use of continuous infusions either through sedation assessment scoring or by daily cessationdaily cessation of Sedative infusions decrease duration of mechanicaldecrease duration of mechanical ventilation and duration of ICU stay.ventilation and duration of ICU stay.
  40. 40. Between 25 and 40%25 and 40% of patients develop signs of respiratory distressrespiratory distress after extubation Decision to extubate. Intensive Care Med 2002; 28:535–546. Epstein SK. Extubation failure, when defined as reintubationreintubation within the subsequent 24–72 h24–72 h, occurs in 5–20% of patients5–20% of patients, depending on the patient population • Risk is greatest for medical and neurologicmedical and neurologic patients. • Reintubated patients experience increased hospital mortality, prolonged ICU and hospital stays, greater need for tracheostomy, and more frequently require long-term acute care
  41. 41. Implications of extubation delay in brain-injured patients meeting standard weaning criteria. Am J Respir Crit Care Med 2000; 161:1530–1536. Coplin WM, Pierson DJ, Cooley KD, et al. Avoidable delays in extubation prolong ICU stay, heighten the risk for pneumonia, and increase hospital mortality Measuring blood gases at the end of the SBT ? • Are blood gases necessary in mechanically ventilated patients who have successfully completed a spontaneous breathing trial? Respir Care 2004; 49:1316–1319. Pawson SR, DePriest JL. • The effect of arterial blood gas values on extubation decisions. Respir Care 2003; 48:1033–1037. Salam A, Smina M, Gada P, et al.
  42. 42. Risk factors for extubation failure in patients following a successful spontaneous breathing trial. Chest 2006; 130:1664–1671. Frutos-Vivar F, Ferguson ND, Esteban A, et al. In general, traditional weaning predictorstraditional weaning predictors perform poorlypoorly in predicting extubation outcomepredicting extubation outcome
  43. 43. One promising technique has demonstrated that risk of extubation failure is associated with greater time needed togreater time needed to return to baseline minute ventilation after resumption of fullreturn to baseline minute ventilation after resumption of full ventilatory supportventilatory support Serial measurements of f/VT can predict extubation failure in patients with f/VT < or 105? J Crit Care 2008; 23:572–576. Teixeira C, Zimermann Teixera PJ, Hohe¨ r JA, et al.
  44. 44. Respiratory failure in chronic obstructive pulmonary disease after extubation: value of expiratory flow limitation and airway occlusion pressure after one 0.1 second (P0.1). J Crit Care 2008; 23:577–584. Vargas F, Boyer A, Bui HN, et al. Measuring the airway occlusion pressure at 0.1 sairway occlusion pressure at 0.1 s (P0.1) and the degree of expiratory flow limitationdegree of expiratory flow limitation
  45. 45. Extubation failure often results from inability to protectinability to protect the airwaythe airway and manage respiratory secretionsmanage respiratory secretions Recent RCTs demonstrate that systemic corticosteroidssystemic corticosteroids can reduce postextubation stridor, especially in high-riskcan reduce postextubation stridor, especially in high-risk patientspatients Intravenous injection of methylprednisolone reduces the incidence of postextubation stridor in intensive care unit patients. Crit Care Med 2006; 34:1345–1350. Cheng KC, Hou CC, Huang HC, et al.
  46. 46. Intravenous injection of methylprednisolone reduces the incidence of postextubation stridor in intensive care unit patients. Crit Care Med 2006; 34:1345–1350. Cheng KC, Hou CC, Huang HC, et al. For example, Cheng et al. Randomized 128 high-risk patients128 high-risk patients (cuff leak volume <24% of tidal volumecuff leak volume <24% of tidal volume) to placebo or methylprednisolone injection (multi-dose or single-dose) during the 24 h prior to extubation24 h prior to extubation. Treatment with methylprednisolone significantly reduced the risk for postextubation stridor and need for reintubation
  47. 47. The ability to protect the airway is also dependent upon cough strengthcough strength and volume of respiratory secretionsvolume of respiratory secretions (e.g. suction requirement > every 2 h) Mental statusMental status is also important, although studies looking exclusively at this parameter have come to conflicting conclusions
  48. 48. Neurologic status, cough, secretions and extubation outcomes. Intensive Care Med 2004; 30:1334–1339. Salam A, Tilluckdharry L, Amoateng-Adjepong Y, et al. Measuring  Peak cough flow rates (cut-off <60 l/min),  Secretions (cut-off >2.5 ml/h),  Abnormal mental status (inability to complete four simple commands) • Highly predictive of extubation outcome. Failing all three criteria led to certain extubation failure, whereas the absence of all threeabsence of all three was associated with only a 3% risk for reintubation3% risk for reintubation
  49. 49. 10% ~ 20%10% ~ 20% of patients with acute respiratory failure require 21 or more days21 or more days of ventilatory support and thus constitute a subset of prolonged mechanical ventilation defined earlier A recent multicenter observational studyA recent multicenter observational study of more than 1400 patients transferred to long-term care hospitals found that 50% could be successfully weaned50% could be successfully weaned from mechanical ventilation
  50. 50. WeaningWeaning efforts should start as soon as possiblestart as soon as possible after transfer as 10–30% of patients10–30% of patients with prolonged mechanical ventilation will tolerate their initial SBT and be liberatedwill tolerate their initial SBT and be liberated The only RCTRCT in prolonged mechanical ventilation found no differenceno difference between PSV weaning and tracheotomy collarPSV weaning and tracheotomy collar trials of increasing duration in 52 COPD patientstrials of increasing duration in 52 COPD patients
  51. 51. • Determining readiness is best achieved using liberal oxygenation criteria • Does not require routine use of weaning predictors • Can often be conducted using protocols driven by respiratory therapists or ICU nurses.
  52. 52. • SBTs should last at least 30 min and can be conducted on low levels of pressure support, CPAP, or T-piece. • Weaning failure often results from an imbalance between respiratory load and capacity. • There is increasing appreciation that cardiac dysfunction can be a limiting factor.
  53. 53. • Randomized trials suggest that NIV (in patients with COPD) and computer-driven approaches show promise as weaning strategies. • New techniques can identify patients at highest risk for extubation failure. • These include the qualitative cuff leak test and an assessment that integrates cough strength, the volume of respiratory secretions, and mental status. • When used in high-risk patients NIV can decrease extubation failure and the need for reintubation.

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