weaning from mv - nexcob · weaning from mv j.g. van der hoeven ... normal weaning clinical...
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Normal weaning
Clinical improvement, P/F ratio > 150 (FiO2 ≤ 0.5 en PEEP ≤ 8), stable hemodynamics
SBT (30 minutes - 2 hrs) T-piece/CPAP/PSV
Success Failure
Cough?Swallow?
Extubation
Once daily2 - 25%
+ analysis
Introduction and focusIn most patients, mechanical ventilation can be dis con-tinued as soon as the underlying reason for acute respiratory failure has been resolved. However, 20% to 30% of patients are considered di! cult to wean from mechanical ventilation. Weaning failure is defi ned as the failure to pass a spontaneous-breathing trial or the need for reintubation within 48 hours following extubation [1]. " e risks associated with post-extubation distress and reintubation are considerable. " erefore, clinicians often choose to use a two-step diagnostic approach before extu bation. First, weaning parameters are assessed (screening), and, second, a weaning trial is initiated. " e validity of the di# erent screening tools (for weaning), such as the rapid shallow breathing index and maximal inspiratory pressure, has been discussed in detail else-where [2]. Di# erent techniques have been used for wean-ing and these include gradual reduction in mandatory rate during intermittent mandatory ventilation, gradual reduction in pressure support, and spontaneous breath-ing through a T-piece. Esteban and colleagues [3] con-cluded that trials of spontaneous breathing resulted in
faster liberation from mechanical ventilation compared with weaning using pressure support or intermittent mandatory ventilation. However, other studies failed to prove the superiority of spontaneous-breathing trials over pressure support ventilation as a weaning technique [4,5]. " ese di# erences in outcome most likely are related to the di# erent designs of these studies, patient charac-teristics, and durations of mechanical ventilation before initiation of weaning. In-depth discussion of weaning techniques is beyond the scope of this paper and has been published earlier [2].
" e pathophysiology of weaning failure is complex and often multifactorial. Accordingly, determining the reason and subsequently developing a treatment strategy require a dedicated clinician with in-depth knowledge of the pathophysiology of weaning failure. Several reviews have been published on weaning failure, but most focus on only one aspect of weaning and therefore are of limited help to clinicians. Complex clinical problems probably benefi t from a structured approach. An ‘ABC approach’ is valuable in training juniors in trauma management [6]. In this paper, we present an opinion-based ‘ABC approach’ for di! cult weaning. Unlike the ABC in trauma medicine (‘treat fi rst that kills fi rst’), our ‘weaning ABC’ does not emphasize a specifi c order of assessment but is purely alphabetical and has the advantage of ‘forcing’ the clinician to systematically review the most likely causes for failed weaning. With the understanding of the barriers that impede successful weaning in a specifi c patient, a tailored treatment strategy that may reduce duration of mechanical ventilation can be designed. " e following topics should be evaluated in a di! cult-to-wean patient (Figure 1): airway and lung dysfunction, brain dysfunction, cardiac dysfunction, diaphragm dys-function, and endocrine dysfunction. " e algorithm presented in Figure 1 shows possible strategies to confi rm the role of any of these items and options to reduce the contribution to weaning failure.
Airway and lung dysfunctionElevated airway resistance, reduced respiratory system com pliance, and impaired gas exchange increase the work of breathing and as such contribute to weaning
AbstractAbout 20% to 30% of patients are di! cult to wean from invasive mechanical ventilation. The pathophysiology of di! cult weaning is complex. Accordingly, determining the reason for di! cult weaning and subsequently developing a treatment strategy require a dedicated clinician with in-depth knowledge of the pathophysiology of weaning failure. This review presents a structural framework (‘ABCDE’) for the assessment and treatment of di! cult-to-wean patients. Earlier recognition of the underlying causes may expedite weaning from mechanical ventilation.
© 2010 BioMed Central Ltd
Clinical review: The ABC of weaning failure - a structured approachLeo M Heunks* and Johannes G van der Hoeven
R E V I E W
*Correspondence: [email protected] of Intensive Care Medicine (632), Radboud University Nijmegen Medical Centre, Postbox 9101, 6500 HB Nijmegen, The Netherlands
Heunks and van der Hoeven Critical Care 2010, 14:245 http://ccforum.com/content/14/6/245
© 2010 BioMed Central Ltd
Recognise those at risk
0
15
30
45
60
Simple weaning Difficult weaning Prolonged weaning
6
39
55
%
N = 2714
Extubation > 7 daysfrom first attempt of withdrawal
Peñuelas O. Am J Respir Crit Care Med 2011;184:430-437
Disease severity at admissionDuration of MV before first attempt
Chronic pulmonary diseasePneumonia
PEEP before weaning
Extubation outcome after prolonged MV
CharacteristicsSuccessful extubation
(N = 92)Failed extubation
(N = 27)P-value
Respiratory rate > 30 46 (50%) 15 (56%) 0,612
Minute ventilation > 10 49 (53%) 14 (52%) 0,897
Tidal volume < 5 ml/kg 27 (29%) 10 (37%) 0,448
RSBI > 105 42 (46%) 14 (52%) 0,57
PI max < - 20 cm H2O 9 (10%) 2 (7%) 0,999
GCS > 10 65 (71%) 18 (67%) 0,692
Ineffective cough 27 (29%) 23 (85%) < 0.001
Abundant secretions 8 (9%) 2 (7%) 0,999
Purulent secretions 31 (34%) 9 (33%) 0,972
Positive fluid balance 22 (24%) 10 (37%) 0,176
MV for 25 ± 6 days
Chun-Ta Huang. Resp Care 2013
What can we do in the early phase?
Try to avoid controlled ventilationJaber S. Am J Respir Crit Care Med 2011;183:364-371
Sedation - SLEAP trial
• Does daily sedation interruption improve outcome when protocolised sedation is already implemented?
• Multicenter RCT: Protocolised sedation ± daily sedation interruption (N = 423)
• Primary outcome - time to successful extubation
Mehta S. JAMA 2012;308:1985-1992
Mehta S. JAMA 2012;308:1985-1992
Protocol Protocol + Daily interruption P-value
Successful extubation (D) 7 (3 - 12) 7 (4 - 13) 0.52
Days in ICU (D) 10 (6 - 20) 10 (5 - 17) 0.36
ICU mortality (%) 24.9 23.4 0.72
Hospital mortality (%) 30.1 29.6 0.89
Higher nursing workload with daily interruptionMore sedatives/opiates with daily interruption
Determine excessive load
TLC$
0$Ppl$/$Pes$ +$-$
FRC$
Lung$volume$
passive$infla9on$$(relaxed$chestwall)$
ac9ve$infla9on$(lung$elas9c$recoil)$
resis9ve$inspiratory$WOB$
elas9c$inspiratory$WOB$
PEEPi
PEEPi$inspiratory$WOB$
expiratory$WOB$FRC$
Vt$
Vt$
Load reduction
• Decrease airway resistance (major/minor airways)
• Treat pulmonary edema / atelectasis
• Remove pleural fluid
Remove pleural fluidN = 168
Retrospective study
0
2
4
6
8
PF drainage Control
Dura
tion
of M
V (D
ays)
P = 0.03
Kupfer Y. Chest 2011;139:519-523
Pleura effusion drainage in MV patients
PaO2/FiO2 ↑ 18% (95 CI 5 - 33%)
Pneumothorax 3.4% (95 CI 1.7 - 6.5%)
Hemothorax 1.6% (95 CI 0.8 - 3.3%)
Pneumothorax with ECHO
OR 0.32 (0.08 - 1.19)
19 observational studies (N = 1124)Goligher EC. Crit Care 2011;15:R46
Spontaneous Breathing Trial
Work of Breathing ↑ Adrenergic stress ↑ IT pressure ↓
RV dilatation and increased LV afterload
Increase in LV preload / decrease in LV compliance
Pulmonary edema
Diastolic heart failureA frequent cause of weaning failure
0
5
10
15
20
25
Baseline Spontaneous ventilation
E/Ea
Failure Success
Moschietto S. Crit Care 2012;16:R81
0"
50"
100"
150"
200"
250"
MV" Start"trial" Einde"trial"
Systolische+bloe
ddruk+(m
m+Hg)+
Controle"
Nitroglycerine"
0"
5"
10"
15"
20"
25"
30"
35"
MV" Start"trial" Einde"trial"
Wiggedruk
)(mm)Hg))
Controle"
Nitroglycerine"
COPD - N = 12
After failure SBT (control) 90% successful with NTG
Routsi C. Crit Care 2010;14:R204
Consider nitrates
Other inotropic agentsDobutamine/Levosimendan in 10 COPD patients withlarge increase in PAOP during spontaneous breathing
Ouanes-Besbes L. J Crit Care 2011;26:15-21
RPP = rate pressure product
If the diaphragm is weak
• Early mobilisation
• Electrical muscle stimulation
• Respiratory muscle training
• Medication
Early mobilisationN = 104
Control Protocol P-value
Independent at HD 59% 35% 0.02
ICU delirium (D) 4 (2-7 2 (0-6) 0.03
ICU paresis at HD 49% 31% 0.09
Ventilator-free days 21 23.5 0.05
LOS ICU 7.9 5.9 0.08
Schweickert WD. Lancet 2009;373:1874-1882
Electrical stimulationN = 140 - only 52 evaluated
0
15
30
45
60
CIPNP (%) MRC score
EMS Control
P = 0.04 P = 0.04
MV significantly shorter in EMS group (1 [0-10] vs 3 [0 - 44], p 0.003)
Routsi C. Crit Care 2010;14:R74
• Daily sessions of 55 minutes
• Bilateral vastus lateralis/medialis and peroneus longus
• Biphasic, 45 Hz, 0.4 ms pulse duration, 12 seconds on and 6 seconds off
Muscle training
Threshold® PEPRespironics
Threshold® IMTRespironics
Inspiring throughexhalation port
4 sets of 6 - 10 breaths per day (5 days/week)
PFlex® IMTRespironics
Efficacy trial
0
20
40
60
80
Weaned D 28
47
71
%
IMT Sham
-80
-60
-40
-20
Pre PostM
IP (c
mH
2O)
IMT Sham
P < 0.0001
P = 0.039 N = 69
Martin AD. Crit Care 2011;15:R84
Inspiratory muscle strength Weaning success
Weaning duration (hours) Survival
Moodie L. J Physiother 2011;57:213-221
Muscle damage in COPD patients? - Optimal program?
Levosimendan improves neuromechanical efficiency
Doorduin J. Am J Respir Crit Care Med 2012;185:90-95