Loh Tsee Foong
Director Children ICU KKH
Dy/Director Education Office Paeds ACP
A/Professor Duke NUS SoM
Lead, Child Protection Team
Director PFCCS Singapore

Hypoxaemia
• ARDS, ALI, AHRF
• Oxygenation indices (P/F; OI)
• American European Consensus Conference
• Berlin definition update on ARDS
• PARDS PALICC group
 Ventilator
modes
• Basic P-CMV; P-AC; PRVC; VC-AC
• Non basic HFOV APRV BCV HFPV
• Adjuncts (iNO, PP, RM)
 EmBase
PubMed Medline
• Exclude case reports
 Outcomes
• Mortality
• Oxygenation indices – OI P/F SaO2/FiO2
• Performance scores
• LOS length of stay
• VFD ventilator free days
• Side effects
 Very
often medical care for child is
based on what works for adults
• Selective adoption
 Ventilator Induced Lung Injury VILI/ Open lung
 Low Vt, higher PEEP, Limiting Ppk Pplat
 Adjuncts (iNO, RM, PP, fluid management, steroids)
 Permissive Hypercapnia and allowable saturations
 VC-AC; PC-AC; PRVC
 Mortality have improved
• What about lessons from neonatology?
Khemani R et al AJRCCM 182: 1465-74
Needham DM et al BMJ 344: e2124
 PALIVE
study “What the real world is”
• 59 PICU in North America and Europe
 Variability in practise
 Use of CMV 75% HFOV 16% NIV 8%
 PC-CMV 44% with 8.3+/-3.3 ml/kg
 No clear PEEP & FiO2 relationship
 Adjunctive treatment not standardised
• Few explicit protocols in paediatric ventilation
• Use of ideal or actual body weight uncertain
Santschi M et al PCCM 11: 681-9
“What the ideal world is”
Given 3 hypothetical
cases to interact
• Mild, moderate, severe ALI
Discrepancy
in
• Use of PEEP
 Elevated PEEP to 1214cmH2O
 50%kept PEEP <8cmH2O
• Vt used
 None chose Vt>10ml/kg
 20% used Vt>10ml/kg
• Adjuncts
 iNO 12.7% PP 17.6%
 90% use both
• HFOV use 8.5%
 No uniformity in theory
 Mismatch
in
knowledge and
practise
 Limited
evidence to support PC or VC
• PC decelerating flow
• Pressure Regulated Volume Control
 OI; PedsLIS; P/F; Cdyn
relate to mortality
• SCT n=398 AHRF PCV lung protective strategy
• Vt 610ml/kg
 Trend for higher mortality with lower Vt & VFD
 Worse lung had lower Vt
 Higher Vt and better outcomes in less severe ALI
?
Optimal Vt used under LPS
 Use of permissive hypercapnia
 PC CMV
• Generated Vt is function of severity of lung dis
• Do we need to standardised Vt?
 Smaller diameter airways  high resistance
 Use of higher PEEP  hyperinflation
 Higher dead space in children  hypo alveolar MV
Prella M et al Chest 122: 1382-8
Khemani G et al ICM 35: 1428-37
 High
Frequency Oscillation Ventilation
• Lung protective features
 Use in 30-50% of paediatric ARDS/ALI
• Lack of universally accepted practice for
initiation or use
 Evidence for variability
 Practice has not changed over decades
 Based on OI
 >3d of MV before HFOV use
Mehta NM et al Curr Opin Crit Care 10: 7-12
Ben Jaballah N et al PCCM 7: 362-7
Arnold JH et al CCM 28: 3913-9
Erickson S et al PCCM 8: 317-23
Randolph AG et al JAMA 288: 2561-8
 ARDS
n=25
 Failed CMV
 Improved
oxygenation
• OI 38  17
• P/F 65152
• Unchanged
haemodynamics
 Overall
mortality
 AHRF
n=17
 Failed CMV
• PCO2 >85 PO2 <60
 Improved
oxygenation
• 17% trachael bleeding
 Overall
mortality
47%
52%
Pinzon AD et al Rev Assoc Med Bras 59: 368-74
Tassiou I et al ICM 36 (S2) S108
 Retrospective
study n=69 SCT Argentina
• ARDS failed CMV 8h no ECMO use
• 80% LRTI or sepsis
• 60% co-morbidities
• 93% refractory hypoxia
• 33.4% survival
• Non survivors
 Higher acuity scores MOF
 Worse LIS & oxygenation indices
Taffarel P et al Arch Argent Pediatr 110: 214-20
 N=80
ARDS 40%
 Time
on CMV
• SCT Portugal
• 8.8h (survivor) vs 133h
• 85% prior CMV 12h
(non survivor)
• 30h (survivor) vs 63h
(non survivor)
• Mortality 40-50%
• 70% refractory
•
•
•
•
•
hypoxia <90%
Sat/FiO2 improve 24h
Reduction in FiO2
Reduction PCO2
84% survivors
Death
 MOF, HLHS, shock & resp
failure
Moniz M et al J Pediatr 89: 48-55
 Fort et al 5.1d
 Mehta et al 5.6d
Fedora M et al Scr Med 74: 233-44
Slee-Wijffels FY et al Crit Care 9: R274-9
Fort P et al CCM 149: 818-24
Mehta S et al CCM 29: 1360-9
 Rescue
or preemptive use?
 Cochrane review 2011 update
 AHRF
n=28
 Lung protective
strategy
 Improved
oxygenation indices
• P/F 30-40%
• reduction in FiO2
• HFOV better at T8hr
• Similar after 24hrs
Fioretto JR et al Pediatr Pulmonary 46: 809-16
 Theoretical
advantage
• Constant distending pressure
 Higher MAP lower Ppeak
• Spontaneous breathing
• Concern over release phase
 Not
new!
 Limited RCT in adult
 None in paediatrics
Varpula T et al Acta Anaesth Scand 48: 722-31
Siau C et al CCM 37: 2448-54
Randolph AG et al CCM 37: 2448-54
Spontaneous Breath
PEEPH
P
PEEPL
Synchronized Transition


Very short release time TL – I:E reverse
“CPAP with release” or “BiPAP IRV”
• Recruitment effect

No feedback loop, PS and all SB at TH
• Release ventilation during
APRV assoc with decreasing
Paw and lung distension
Habashi NM et al CCM 33(3)supp: 228-240
• Tidal ventilation during
CMV assoc with increasing
Paw and lung distension
• SB in APRV
improve lung
aeration in OA ALI
– N=24 pigs OAALI
assign to APRV+/SB
– PaO2 better in SB gp
– Higher EELV on CT
Wriggle et al Anesthesiology 99: 376-84
APRV - SB
APRV + SB
 Effectiveness
of spontaneous respiration
• Improved pulmonary perfusion
 Prospective crossover cohort study APRV vs PC-SIMV
 N=20 post-tetralogy, BCPC or Fontan repair
 Demonstrated improved pulmonary blood flow and
oxygen delivery in patients post tetralogy rand BCPC
repair
• Better cardiopulmonary interactions
Walsh et al CCM 39(12): 2599
 Assess
effectiveness of APRV in children
• PRCT crossover MV<7d APRV vs VCV-SIMV
• n=15 mild-mod lung disease (postop,
pneumonia)
 Excludes obstructive airway disease, CHD
 SIMV and APRV crossover
 Inspiratory Paw lower with APRV
 Comparable oxygenation and ventilation
Schultz TR et al PCCM 2: 243-46
 Retrospective
review Single center PICU n=13
• Assess efficacy and effectiveness
• American -European Consensus ARDS criteria
• OI > 10 or clinical decision by physicians
 No deterioration in haemodynamics & respiratory by APRV
 pO2/FiO2 no change in 1 and 12 hr post-APRV, improved
thereafter
 OI increased at 1 and 12 hr post APRV, none thereafter
 N=5 died (38%)
 4/5 were immunocompromised with HFOV introduced
Kawaguchi A. et al CCM 37(12S): A465
 H1N1
pneumonia
 Infants with ARDS
 H1N1 on PCR with <7d
Hisashi et al Ind J Paed 78: 348-350
Demet D et al Ind J Paed77(11) 1322
Loh TF et al CCM 37(12S) 395
 N=5 diagnosed with ALI (a/A < 0.2), PEEP >=7
cmH2O,
 Open Lung ventilation with protective lung strategy
 If OI >0.1 or FiO2 >0.8 converted to APRV
 Better oxygenation and ventilation indices over 24hr
 Decrease FiO2 and MAP over 24hr
 N=4 survive N=1 death (on HFOV & iNO)
 Reduced sedation needs after APRV in all patients
100
90
Use of HFOV 2006-2012
APRV introduced
80
70
60
Admissions
tens/yr
Percent MV %
50
40
30
20
10
0
2006
2008
2010
2012
 Pre-emptive
application of APRV in rat
model of trauma/ haemorrhagic shock
with ARDS n=10
 VC-SIMV Tv 10ml/kg PEEP 0.5cmH2O
 APRV Ph 15-20 Pl 0 cmH20 Th 1.3-1.5s Tl 0.11-0.14s
 Prevented ALI measured on P/F ratio
 Correlated with histopathology between 2 groups
 BAL dcr bronchial protein, incr Prot B and epithelial
cadherin
• APRV attenuates clinical and
histological lung injury in
trauma/ haemorrhagic shock
Roy SK et al Shock 40(3): 210-216
 Retrospective
n=60 failed CMV SCT
• Immunocompromised ARDS
• Either HFOV (n=31) or APRV(n=29) no crossover
 Left to physician discretion
• CMV 1d
• Improvement in P/F OI PCO2 with lower MAP
• Mortality APRV 62% HFOV 65%
 Stem Cell Transplant worse outcome
• N=6 started on ECMO (only 1 survivor)
• P/F 24h predicted survivors
• Other cutoffs for APRV & HFOV for survivors
Yehya N et al PCCM 15: e147-56
 Yes
• Even as rescue when CMV fails
• HFOV use early
• APRV use possibly preemptively
 PARDS
 diverse etiologies
 myraid of inter-related pathophysiological events
 patient comorbidities and concurrent treatments
 differing responses and rehabilitative potential
 No
particular ideal ventilatory mode
 What is lung protective strategy in paed?
 Need to translate theory into practice
 Preemptive therapy or early rescue
 Role of adjuncts
PH
Spontaneous Breaths
PL
Pressure Support
P
Synchronized Transitions
• Spontaneous breaths at 2 pressure levels
• PH transition to PL during expiratory
phase
PEEP
H
PEEPHigh Pressure Support
Pressure Support
P
PEEPL
 Pressure
support of SB at PH & PL
 TH : TL 1:2-3 ratio
Preservation of respiratory muscle
 Better patient-ventilator synchrony

• Less sedation, blockage, ?ventilator days

Encourages diaphragmatic contractions
• Allow gas to enter dependent (ventilation) portion of lung




Recruit dependent units without Paw increases
V/Q matching
Improve OI with less Paw
SB at TH allows for further recruitment
• Unlike mechanical breaths preference for non-dep part
lungs
Froese A et al Anesthesiology 41: 242-55
Rehder K et al J Appl Physio 42: 391-402
 Haemodynamic
effects
• Reductions in pleural pressures
 Improve venous return, renal/splanchnic flow by lowers
RAP
• Increasing abdominal pressure encourages venous
return

Pressure High (PH)
• Higher of 2 Baseline airway pressure
• Oxygenation goal

Time High (TH)
• Length for which PH is kept

Pressure Low (PL)
• Set to deliver release volume
• CO2 clearance

Time Low (TL)
• Length for which PL is kept
 Not
new! 1987
 Time triggered pressure limited time
cycled mode
 Allow spontaneous during breathing
cycle
 Breathing at 2 levels CPAP - BiPAP
 Benefits of CPAP in ALI
• Improved PV and less WOB
Downs JB et al CCM 15: 459-61
Stock CM et al CCM 15: 462-66
 Patients
with ALI or low compliance
• Goal to recruit with PH and avoid de-recruitment
during releases PL
 Airway
disease
• High peak expiratory flows during release phase
 Little or no PEEP to resist expiratory flow
• Expiration can occur throughout cycle
Habashi NM et al CCM 33(3)supp: 228-240
 Animals
• Lamb in OA ALI
 Retrospective
Martin LD et al Crit Care Med. 1990;18:231
reviews
Hales R et al Respir Care 49: 1441
 Case reports
Foland JA et al Respir Care 46: 1019-23
• Cardiac surgery
Jone R et al Respir Care 49: 1414
• Preterm infant with
BPD
De Carvalho WB et al Rev Assoc Med Bras 46: 166-73
• APRV vs SIMV
Hutchison AA et al Abstract 10 REaSoN meeting Warwick 2004
th
Crooke C et al Respir Care 49: 1376
 N=24
adult severe ARDS
 APRV+/-SB vs PSV with equal MV and Paw
• Effect seen in APRV/SB
• Reduce intrapulmonary shunt, Vd
• Increase in RVeDV, SV, CI, mixed venous and DO2
• Decrease in PVR, oxygen extraction
Putensen C et al AJRCCM 159: 1241-8
Putensen C et al Anesth Int Care 33: 218-22
 N=30
ARDS trauma
 APRV/SB vs PCV(+NMB) weaned with
APRV
 APRV/SB assoc
 Better compliance, CI, PaO2, DO2
 Reduced shunt, O2 extraction
• Lower ventilator, intubation and LOS
 Concerns
PCV group
 3d treatment with NMB
 PaO2/FiO2 much lower from baseline
Putensen C et al AJRCCM 164(1): 43-9

PRCT n=58 ARDS APRV vs SIMV/PS
• Better inspiratory Paw in APRV
Varpula T et al Acta Anesth Scand 47(5): 516-24
• PEEP, gas exchange and haemodynamic indices, LOS,
mortality similar

PRCT PP in SIMV PCV/PS vs APRV n=45
• PP for 6hr at 6hr and 24hr admission according P/F
• Pre prone APRV better oxygenation
• 1st prone same improvement in P/F
• 2nd prone better P/F on APRV
• >24hrs to max benefits?
Varpula T et al Acta Anesth Scand 47(5): 516-24
 APRV
vs CMV in ARDS trauma n=30 PRCT
• Better gas exchange and haemodynamics
• Less sedation
Varpula T et al Acta Anesth Scand 2003
• Less ventilator and ICU days
 APRV
vs PCV-IRV ARDS
Kaplan LJ, et al. Crit Care 2001; 5(4):221-6
• Similar oxygenation and ventilation
• Better haemodynamic CI, DO2, SV
• Less sedation needs
 PRCT
uneven randomisation
 APRV vs CMV vs SIMV post cardiac op
n=596
Rathgeber J et al Eur J Anaesth 14: 576-82
• Intubation time 10hr vs 15hr vs 13hr
• Less sedation and anaglesia

Open lung strategy
•
•
•
•
Recruitment ripple effect of stablising alveoli
Promote airway opening
Continuous recruitment manoeuvre with SB
Target settings most vent cycle PV relationship above LIP
Release tidal breath to clear CO2 without need for
positive pressure tidal ventilation
 Spontaneous breathes
 Ventilation release phase at expiratory limb PV loop

• Open lung TL too short for de-recruitment
• Maintain autoPEEP in PL
Rimensberger P et al CCM 27: 1946-52
 Lower
Pk
 Less WOB, sedation needs
 Improve oxygenation and able to
ventilate
 Better haemodynamics
 Limited outcome studies
 ? Reduce need in HFOV
 High
PH levels with low pleural pressures
• High transpulmonary pressures and volutrauma
 PL
at 0 cmH2O may result in large release
volume
 ? Cyclical release and opening of alveoli
 Titrate TL to autoPEEP need constant adjustment
 autoPEEP not heterogeneous amongst disease
lung
 Obstructive airway disease
 Understand
the unique features and
benefits of „new‟ modes of ventilation in
relation to patient lung disease and
targets
 No „Ideal‟ mode of ventilation
 Combination of modes use
 Outcome studies ?realistic
 Retrospective
AHRF
 P/F increased by
mean 28.5
 OI not changed
Kambhampati S et al CCM 40: 12(S)1015
 Case
reports
Krishnan J et al Pediatr Pulmonol 42: 83-8
Schultz TR et al PCCM 2: 243-6
Demirkol D et al Ind J Pediatr 77: 1322-5
 Based
on ARDSnet
low Vt strategy
 Using SMA clamping and
release
 Induced peritoneal
sepsis
 Ventilated 1hr 10ml/kg
 Low Vt 6ml/kg PEEP/FiO2
and Pplat <30
 APRV
 Antibiotics given
 Sacrificed after 48h
 Histology, BAL, IL-6
 APRV






group
preserved P/F
Better lung compliance
Surfactant abundance
Less pulmonary edema
Reduced IL6
Fairly normal lung
histology
 SIRS
induced ARDS
can be altered with
preemptive APRV use
 Outcome
studies vs lung protective
ventilation
 Role in relation to HFOV

Sustained mean alv volume
allows for gas diffusion and
combined with cardiac output
enable constant gas diffusion
between blood and alveolar
compartments
Habashi NM et al CCM 33(3)supp: 228-240
●
Release ventilation cycle oxygen rich
gas with CO2 rich gas to re-establish
diffusive gradients
• EELV determined by PL and TL
– Artificial airway imposes resistance
– Non linear flow dependent resistive load from high lung
volume
– Resistive pattern is highest at initial phase of TL
– Terminate before expiratory load is discharged to keep
residual pressure and lung volume
– PL recommended b to be 0cmH2O
Habashi NM et al CCM 33(3)supp: 228-240
• EELV determined by PL and TL
–
–
–
–
Artificial airway imposes resistance
Non linear flow dependent resistive load from high lung volume
Resistive pattern is highest at initial phase of TL
Terminate before expiratory load is discharged to keep residual
pressure and lung volume
– PL recommended b to be 0cmH2O
Habashi NM et al CCM 33(3)supp: 228-240

TH >> TL
• TH 4-8s TL 0.2-0.8s
• 10-20 release breaths per minute

PH
• match Pplat on CMV or >30cmH2O

PL allow release to clear CO2 but prevent de-recruitment
by keeping end expiratory volume
• 0cmH2O or match expiratory flow terminal 25% autoPEEP
• May add PL
• 6-8 (11-12) ml/kg IBW
 Effect
6hours
 Allow SB with appropriate sedation
 High PH open lung units at critical opening
pressure
 High TH recruits lung units with long time
constants
• Decrease in FiO2
• Increase release volume
 Re-set
CO2 goals
 Avoid over sedation
 Increase TL
 Increase PH or decrease TH
 Reduce
PH and PL keeping release volume 6-
8ml/kg
• Decrements of 2-3 cmH2O
 Increase
TH to allow more SB
• Increments 0.5 to 12-15
 Transition
to PSV or CPAP/ATC when PH
10-15 cmH2O and PL 5 cmH2O
• Concern of PS causing lung over-distension, high
transpulmonary pressure, uncoupling of SB
Habashi NM et al CCM 33(3)supp: 228-240
 TH kept
as much of the time as possible for
continuous recruitment effect
 Release tidal breath to clear CO2 without
need for positive pressure tidal ventilation
 Allowance of SB at all cycles
 Prevent de-recruitment by manipulating TL
and PL to maintain EELV

n=18 APRV vs VCIRV
Sydow et al AJRCCM 149: 1550-6
 Better gas exchange and CP mechanics

n=50 APRV vs CMV
 Better oxygenation


Rasanen et al AJRCCM 1991: 1234-41
Lang n=18 APRV vs CV
Dart et al n=60 trauma ALI retrospective APRV vs PCVSIMV
• Lower Paw and better P/F


Dart BWt et al J Trauma 59: 71-6
1991 APRV vs CPAP vs CMV in OA ALI sheep
model
1993 n=15 APRV vs SIMV ALI postop
• similar
Martin LD et al CCM 19: 373-8
Davis K et al Arch Surg 128: 1348-52
Artificial
CMV (IPPV)
CMV (CPPV)
IMV, PSV, BIPAP
APRV
Spontaneous
T Piece
SBT
HFOV
CPAP
Oxygenation Level
IPPV: Intermittent positive pressure ventilation PSV: Pressure support ventilation
CPPV: Continuous positive pressure ventilation
IMV: Intermittent mandatory ventilation
BIPAP: Biphasic positive airway pressure
APRV: Airway pressure release ventilation
CPAP: Continuous positive airway pressure
 Group
of techniques using RR>>>CMV
• HFPPV
Less Vt
• HFJV
• HFOV
Sub Vd
Slutsky AS et al Am Rev Resp Dis 138: 1175-183
60-120bpm
400bpm
1000-2000bpm
Volume
To target “injury
free” zone
HFOV
Zone of Overdistention
Barotrauma Alveolar stretch
Pulmonary edema
Safe
window
Zone of
Derecruitment and
atelectasis
CMV
Biotrauma
Epithelial injury
Pressure
Slutsky & Drazen NEJM 347: 630-1
Pillow JJ et al CCM 33(Supp): S135-141
 Premature
<30wks RDS HFOV vs PSV/VG
• PRCT n=25
• Pre surfactant, 6-18hrs, 1-2d, pre-extubation
bronchial measurements of IL-1β, IL-8, IL-10
• Lower levels in HFOV group
 HFOV
associated reduction in lung
inflammation in preterms RDS vs PSV/VG
Dani C et al Paed Pulmono 41(3) 242-49
 HFOV
as rescue therapy
 Recruitment before HFOV
 Improve oxygen indices
 HFOV
Arnold JH et al CCM 21: 272-8
Rosenberg RB et al Chest 104: 1216-21
vs CMV with crossover to HFOV
 PRCT N=70 DAD
Arnold JH et al CCM 22: 1530-9
 Open lung concept
 Less O2 supp at 30d in HFOV group
 Survival poorer in crossover to HFOV group
 Retrospective
ARDS post CS
• Exclude uncorrected shunt
• Failed CMV
• N=84 ARDS N=64 HFOV
• OI <13 Pplat >28 pH <7.2 CMV 11d
• OI improved
 More in survivors
• 40% mortality
 MOF
 Respiratory failure
Shengli L et al Pediatr Cardio 34: 1382-8
 Retrospective
n=23 Age 10yr+/-10yrs
• Mean OI 36 P/F 109
• Started 4.7d postburn CMV
• Improve oxygenation
 OI & P/F may take up to 24h
 Inhalational injury poor response
 Responders n=16 non responders n=5
 P/F 207 vs 78 (responder improve by D3)
 TBSA 68 vs 42%
 Mortality 29% (responder 60% non responder 20%)
Greathouse ST et al J Burns Care Res 33:425-35
 AHRF
 HFOV;CMV;+iNO
 P/F
in HFOV+iNO
better at T4 T8hrs
 24hr HFOV gp better
oxygenation cf CMV
Dobyns EL et al CCM 30: 2425
 PPHN
n=205
 Failed CMV+iNO &
HFOV
• Started on HFOV+iNO
Kinsella JP et al J Pediatr 131: 55-62
 Retrospective
observational study n=53
single center
• DAD, SAD
 Rescue
therapy HFOV
• Noted higher OI in DAD >35
 Survival
56% DAD 88% SAD Overall 64%
Slee-Wijffels FY et al Crit Care 9(3): R274-9
• N= 23 adult ARDS
(pneumonia, burn, BMT)
• Apache 21=/- 7 LIS 3.4+/-0.6
• Rescue HFOV failing CMV
•
•
•
•
•
PIP (cmH2O) 37 + 4
Paw 24 + 3
PEEP 13.8 + 2.4
PaO2/FiO2 (mm Hg) 100 + 41
OI 33 + 20
Mehta et al. CCM 2001;1360-1369
• Outcomes
• ICU Survival 7/23 (30%)
• Burns 0/5
• 11 withdraw, 2 technicla
problems
• Nonburn patients 7/17 (41%)
• Prior Vent Days 6.1 + 5.6
days
– Non Survivors 7.8 + 5.8 days
– Survivors 1.6 + 1.2 days
• Prospective observational N=156
• Severe ARDS (P/F 91 +/- 48) Mean OI 31)
• Improvement in oxygen indices
• Almost quarter HFOV discontinued
• 22% pneumothroax
• 62% mortality
• Predictors
 Age, APACHE
 pH at initiation
 Duration of CMV
Mehta S et al Chest 126: 518-27
 Use
of HFOV paeds AHRF rescue failed
CMV
• PCT n=20 (pneumonia, sepsis, poisoning, pul
•
•
•
•
•
edema)
Alv-artO2 578torr OI 26
CMV 15.5hr (3.3=/-43hr)
Improved FiO2 and PCO2 1hr to 24 hr
Alv-artO2 and OI improve 1,4,12 hr
75% survival
Jaballah NB et al PCCM 7(4):362-367
• N=10 severe paeds ARDS (P/F 200) DAD with
•
•
•
•
•
•
sepsis
CMV 7ml/kg Pplat < 30cmH2O
Permissive Hypercapnia
OI 13-35 (median 15)
Duration of CMV 3-48hrs (median 4 hrs)
Open lung concept with recruitment
80% survival
Jaballah NB et al Eur J Paed 164: 17-21

HFOV (recruitment) vs PCV (6-10ml/kg) MOAT








PRCT MCT early ARDS (P/F = 200 PEEP 10)
HFOV Paw 45 cmH2O Dp 90 Hz 3-5
Use open lung strategies and permissive hypercapnia
Convert to CMV Paw 24cmH2O FiO2 0.5 SaO2 88%
Improve oxygen indices on HFOV
Survivors predicted by improving OI over 72hrs
30d mortality 52% (CMV) vs 37% (HFOV)
Concerns
 Safety study and not powered for difference
 Days on CV pre HFO (2.7+/-2.7) vs PCV (4.4d+/-7.8)
 Vt PCV 10.2ml/kg IBW and Pplat 38+/-8 cmH2O
Derak S et al AJRCCM 166: 801-8
 PRCT
crossover HFOV vs CV Vt 8-9ml/kg
 N=61 adult ARDS (stop 3yrs)
 No difference in mortality and morbidity
Bollen CW et al Crit Care 9: R430-39
• Post hoc benefit sicker patients (higher OI) on
HFOV
 Prone
positioning
Demory Didier et al CCM 35(1): 106-11
• N=43 adult ARDS Prospective Comparative
 Lung protective CMV 12hrs prone, then 12hr supine
 Lung protective CMV 12hrs supine, then HFOV supine
12hr
 Lung protective CMV 12hrs prone, then HFOV supine
12hr
• P/F and intrapulmonary shunt better in last gp
• HFOV maintained benefits of PP when patient
supine
 Tracheal
gas insufflations improve
alveolar ventilation in HFOV
• PR crossover trial n=14 ARDS <3d OI 23
• HFOV with TGI (6l/min 1hr) and without 1hr for
1d
 Session revered for 1d and 4 RM
 CMV ARDSNet before and after HFOV sessions
• HFO-TGI better P/F , OI, intrapulmonary shunt
and mixed venous
• Haemodynamics, respiratory mechanics
unchanged
Mentzelopoulos S et al CCM 35(6): 1500-8
 RCT
HFOV, CMV with iNO
 n=108 pediatric AHRF
 HFOV plus iNO (n=14) HFOV alone (n=12)
 CMV plus iNO (n=35) CMV alone (n=38)
 Posthoc P/F ratio greatest in the HFOV plus iNO at 4
and 12 hrs
• HFOV plus iNO and HFOV gp greater P/F ratio
improvement at 24hrs
•
Lung recruitment by HFOV enhances
iNO effects
Dobyns et al CCM 2002;30(11):2425
Type
Piston
Diaphragm – MagnetCoil
Spinning Jet
Ventilator
New Calliopeα
VIASYS / Drager/
Sensor Medics
SLE
Oscillation created by a piston
from the expiratory side.
Easy HFO settings. All
parameters are independent.
Amplitude can be finely set by
Features
changing stroke volume in
increments as small as 0.2ml.
PCV and PSV available.
Easy sterilization by detaching
piston unit.
Oscillation source is a
speaker system.
●
●
Weaker power.
Oscillation wave
becomes mixed with
noise, unstable.
●
Parameters cannot be
set independently.
Oscillation source from
a jet flow with a
spinning valve at the
expiratory port.
●
●
Weaker power.
Settings cannot be set
independently.
●
●
It is likely to be
affected by the
compliance of the
breathing circuit.
●
HFO
Setting
Ventilator
Calliopeα
Babylog
Stephanie
SM3100A
SLE5000
SLE2000HFO
Ventilation
Mode
HFO, IMV,
CPAP
CPAP+HFO,
IMV+HFO
CPAP+HFO,
IMV+HFO
HFO
CPAP+HFO,
IMV+HFO,
HFO
CPAP+HFO,
IMV+HFO
MAP
3～40 cm
H2O
5～25cmH2O
0～35cmH2O
0～40cmH2O
Frequency
5～17Hz
5～20Hz
5～15Hz
3 ~ 15Hz
3～20Hz
3～20Hz
Stroke
volume
0～80 ml
x
x
%
x
x
SI
Manual
○
○
x
x
x
0～35mbar
3 ~ 45 cm
H2O
 VILI
is major concern in ARDS/ALI
• HFOV would be ideal
 Studies
suggesting benefit esp early use
 Outcome studies disappointing
 Adjunct uses
To adjust HFOV, which machines to use
 How to apply early – Who are responders?
 Lung protective strategy in HFOV

• Recruitment

What is best surrogate marker
• OI, P/F? Role of adjuncts therapies
• Aerosols, iNO
Time for new ventilator?
OSCILLATE – Canadian Critical Care Trials Group

 Understand
the unique features and
benefits of „new‟ modes of ventilation in
relation to patient lung disease and
targets
 No „Ideal‟ mode of ventilation
 Combination of modes use
 Outcome studies ?realistic
 Compare
weaning of infant recovering
from ARDS treated with HFOV
• N=10 NAVA & n=20 PSV historical control
• NAVA
 Lower HR & MAP ? Comfortable
 P/F decreased less
 Lower PCO2 Ppeak Higher MV
 COMFORT score better
Piastra M et al PCCM 15(4S) no 47
 Retrospective
ARHC SCT n=31 burns
• Failed CMV (HFOV 3; PC-CMV 15; PRVC 16)
 1d OI 18.7 P/F 131.5
• Lower Ppk similar MAP post HFPV for 48h
 OI 18.7 11/7 12h
 PCO2 8455 6h
 MAP 3830
• Airleak Haemodynamic Vasopressor unchanged
• Ventilated mean 4d
• Mortality 16.1%
• N=3 failed HFPV for P-V dyssynchrony
Rizkalla NA et al J Crit Care 314: e1-7
 HFOV 1 ECMO 2
 N=64
paediatric burn SCT
• CMV or HFPV
• Improved oxygenation at lower Ppk
• Mortality ARDS evolution sepsis not different
Carman B et al J Burn Care Rehabil 23: 444-8
 Used
in adult and children smoke
inhalational and polytrauma
Salim A et al CCM 33(3S): S241-5
Cioff Jr WG et al Ann Surg 213: 575-80
Cortiella J et al J Burn Care Rehabil 20: 232-5
Rue III RW et al Ann Surg 128: 772-8
Reper P et al Burns 28: 503-8
 Retropsective
n=60 early ARF SCT
• CMV; NIPPV; BCV
• Oxygenation, Ventilation & vital signs improve in
all 3 groups
• Duration CMV 182.3h; NIPPV 80.hd; BCV 64.2h
• LOS 17.7d CMV; 19d NIPPV; 10d BCV