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 12-

14cmH2O

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 610ml/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 65152

• Unchanged

haemodynamics

Overall mortality

52%

AHRF n=17

Failed CMV

• PCO2 >85 PO2 <60

Improved

oxygenation

• 17% trachael bleeding

Overall mortality

47%

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%

• SCT Portugal

• 85% prior CMV 12h

• 70% refractory

hypoxia <90%

• Sat/FiO2 improve 24h

• Reduction in FiO2

• Reduction PCO2

• 84% survivors

• Death

MOF, HLHS, shock & resp

failure

Time on CMV

• 8.8h (survivor) vs 133h

(non survivor)

• 30h (survivor) vs 63h

(non survivor)

• Mortality 40-50%

Fort et al 5.1d

Mehta et al 5.6d

Moniz M et al J Pediatr 89: 48-55

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

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

Synchronized Transition

Spontaneous Breath

P PEEPH

PEEPL

• Release ventilation during

APRV assoc with decreasing

Paw and lung distension

• Tidal ventilation during

CMV assoc with increasing

Paw and lung distension

Habashi NM et al CCM 33(3)supp: 228-240

• 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 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

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

0

10

20

30

40

50

60

70

80

90

100

2006 2008 2010 2012

Use of HFOV 2006-2012

Admissions

tens/yrPercent MV %

APRV introduced

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

• Spontaneous breaths at 2 pressure levels

• PH transition to PL during expiratory

phase

Synchronized Transitions

Spontaneous Breaths

P Pressure Support PL

PH

Pressure support of SB at PH & PL TH : TL 1:2-3 ratio

PEEPHigh Pressure Support

P

PEEPL

PEEP

H

Pressure Support

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 reviews

Case reports • Cardiac surgery

• Preterm infant with BPD

• APRV vs SIMV

Martin LD et al Crit Care Med. 1990;18:231

Hales R et al Respir Care 49: 1441

Foland JA et al Respir Care 46: 1019-23

Jone R et al Respir Care 49: 1414

De Carvalho WB et al Rev Assoc Med Bras 46: 166-73

Hutchison AA et al Abstract 10th

REaSoN meeting Warwick 2004

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

• 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

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

• Less ventilator and ICU days

APRV vs PCV-IRV ARDS • Similar oxygenation and ventilation

• Better haemodynamic CI, DO2, SV

• Less sedation needs

Varpula T et al Acta Anesth Scand 2003

Kaplan LJ, et al. Crit Care 2001; 5(4):221-6

PRCT uneven randomisation APRV vs CMV vs SIMV post cardiac op

n=596 • Intubation time 10hr vs 15hr vs 13hr

• Less sedation and anaglesia

Rathgeber J et al Eur J Anaesth 14: 576-82

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

Case reports

Kambhampati S et al CCM 40: 12(S)1015

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 Better gas exchange and CP mechanics

n=50 APRV vs CMV Better oxygenation

Lang n=18 APRV vs CV Dart et al n=60 trauma ALI retrospective APRV vs PCV-

SIMV • Lower Paw and better P/F

1991 APRV vs CPAP vs CMV in OA ALI sheep model 1993 n=15 APRV vs SIMV ALI postop

• similar

Sydow et al AJRCCM 149: 1550-6

Rasanen et al AJRCCM 1991: 1234-41

Dart BWt et al J Trauma 59: 71-6

Martin LD et al CCM 19: 373-8

Davis K et al Arch Surg 128: 1348-52

Artificial

Spontaneous

Oxygenation Level

CMV (IPPV) CMV (CPPV)

IMV, PSV, BIPAP

T Piece SBT CPAP

APRV

HFOV

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 60-120bpm

• HFJV 400bpm

• HFOV 1000-2000bpm

Less Vt

Sub Vd

Slutsky AS et al Am Rev Resp Dis 138: 1175-183

Volume

Pressure

Zone of Overdistention

Barotrauma Alveolar stretch

Safe

window

Zone of

Derecruitment and

atelectasis

HFOV

CMV

To target “injury

free” zone

Epithelial injury

Pulmonary edema

Biotrauma

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 vs CMV with crossover to HFOV PRCT N=70 DAD

Open lung concept

Less O2 supp at 30d in HFOV group

Survival poorer in crossover to HFOV group

Arnold JH et al CCM 22: 1530-9

Arnold JH et al CCM 21: 272-8

Rosenberg RB et al Chest 104: 1216-21

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

PPHN n=205

Failed CMV+iNO &

HFOV

• Started on HFOV+iNO

Kinsella JP et al J Pediatr 131: 55-62 Dobyns EL et al CCM 30: 2425

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

• 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

Mehta et al. CCM 2001;1360-1369

• 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

• Post hoc benefit sicker patients (higher OI) on

HFOV

Bollen CW et al Crit Care 9: R430-39

Prone positioning

• 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

Demory Didier et al CCM 35(1): 106-11

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 – Magnet-

Coil Spinning Jet

Ventilator New Calliopeα VIASYS / Drager/

Sensor Medics SLE

Features

Oscillation created by a piston from the expiratory side.

Easy HFO settings. All parameters are independent.

Amplitude can be finely set by 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 0～35mbar

3 ~ 45 cm H2O 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

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 8455 6h

MAP 3830

• Airleak Haemodynamic Vasopressor unchanged

• Ventilated mean 4d

• Mortality 16.1%

• N=3 failed HFPV for P-V dyssynchrony

HFOV 1 ECMO 2 Rizkalla NA et al J Crit Care 314: e1-7

N=64 paediatric burn SCT

• CMV or HFPV

• Improved oxygenation at lower Ppk

• Mortality ARDS evolution sepsis not different

Used in adult and children smoke

inhalational and polytrauma

Carman B et al J Burn Care Rehabil 23: 444-8

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