Presented by Dr.Nial Ferguson at Pulmonary Medicine Update Course held at Cairo, Egypt. Pulmonary Medicine Update Course is the leading Pulmonary Critical Care event in Egypt. Organized by Scribe www.scribeofegypt.com
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High-Frequency Oscillation: New Directions
1. High-Frequency Oscillation:
New Directions for 2009
Niall D. Ferguson, MD, FRCPC, MSc
Assistant Professor
Interdepartmental Division of Critical Care Medicine
University of Toronto
3. Outline
⢠Background on HFO
⢠Ventilator-induced Lung Injury (VILI)
⢠Implementing HFO to prevent VILI
ďˇ Who
ďˇ When
ďˇ How
ď§ Oxygenation & Recruitment
ď§ Ventilation
ď§ Transition back to CV
19. Outcomes
30 Day Mortality
HFOV: 37%
CMV: 52%
Absolute Risk Reduction: 15%
Relative Risk Reduction: 29%
p=0.102
p=0.057 30 d
p=0.078 90 d
HFOV in adults with ARDS is safe and may
improve outcome â more study is needed
22. Background
ďˇ HFO is theoretically ideal for lung protection
ďˇ early RCTs suggest HFO is safe and may reduce deaths
Design
ďˇ multicentre RCT
Population
ďˇ 72 patients with ARDS, at 12 participating sites
Interventions
ďˇ HFO
ďˇ conventional ventilation - a low tidal volume, open lung approach
Primary outcome
ďˇ hospital mortality
Pilot study goals
ďˇ assess recruitment, and barriers to recruitment
ďˇ assess adherence to explicit ventilation protocols
ďˇ measure and understand reasons for crossovers
23. Outline
⢠Ventilator-induced Lung Injury (VILI)
⢠Background on HFO
⢠Implementing HFO
ďˇ Who
ďˇ When
ďˇ How
ď§ Oxygenation & Recruitment
ď§ Ventilation
ď§ Transition back to CV
24. HFOV compared with CMV for Respiratory
Failure in Preterm Infants HIFI Group N Engl J Med 1989;320
673 preterms with respiratory failure within 12 hrs of CMV
346 CMV, 327 HFOV
HFOV - MAP as with CMV, FiO2 was increased first
Results:
Similar Bronchopulmonary Dysplasia & Mortality
Increased pneumoperitoneum, intracranial bleeds,
periventricular leukomalacia
25. Reflections on HIFI
Bryan & Froese Pediatrics 1991;87
1. Goals were not to increase lung volume.
2. PAW weaned before FiO2.
3. Cross centre differences in adverse events.
28. RMs with Conventional Ventilation
⢠Multiple studies â inconsistent results
ďˇ Timing
ďˇ Type of manoeuvre
ďˇ Cause of lung injury
ďˇ How PEEP was set afterwards
⢠With HFO
ďˇ Theoretically RMs may be of more use (because
of lack of tidal recruitment)
ďˇ and may be more effective (because of ability to
set a very high PEEP)
29. PaO2
Time (min.)
HFO - Recruitment Manoeuvres
⢠Oleic Acid Lavaged
Rabbits
⢠Conventional
Ventilation followed
by HFOV
ďˇ With and without
Sustained Inflation
(30 cm H2O for 10 s)
Relationship Between
PaO2 and Lung Volume
During HFOV
Suzuki et al. Acta Pedr Jpn 1992
35. Conclusions
⢠HFO theoretically ideal for preventing VILI â
if used with a strategy to maintain EELV
⢠On balance the potential for benefit with RMs
in HFO seems to outweigh downsides
⢠Lung recruitment is a good thing - If it can be
achieved
ďˇ Ineffective attempts at lung recruitment:
no benefit vs. harmful
36. Outline
⢠Ventilator-induced Lung Injury (VILI)
⢠Background on HFO
⢠Implementing HFO
ďˇ Who
ďˇ When
ďˇ How
ď§ Oxygenation & Recruitment
ď§ Ventilation
ď§ Transition back to CV
44. Conclusions
⢠In addition to targeting lung
recruitment we need to deliver the
lowest VT possible
ďˇ Higher frequencies (facilitated by higher
power / delta P)
ďˇ Controlled cuff leak?
ďˇ Accept a âreasonableâ pH
45. Outline
⢠Ventilator-induced Lung Injury (VILI)
⢠Background on HFO
⢠Implementing HFO
ďˇ Who
ďˇ When
ďˇ How
ď§ Oxygenation & Recruitment
ď§ Ventilation
ď§ Transition back to CV
46. Implementing HFO 2009
⢠Who should we consider as candidates for
HFO?
ďˇ Sick ARDS patients in need of recruitment
⢠When should we use HFO?
ďˇ Rescue therapy for now
ďˇ Maybe earlier rather than later
⢠How we use HFO?
ďˇ Oxygenation = Target lung recruitment
ďˇ Ventilation = Keep tidal volume minimal