HFV - HFOV
SAMANTHA DURHAM & RAJBEER SINGH
What is HFV and types of HFV?
High frequency jet ventilation
high frequency oscillatory ventilation,
high frequency percussive ventilation,
high frequency positive pressure ventilation
What is HFOV?
⧫ A rapid rate and low tidal volume form of mechanical ventilation
⟶ High rates can be between 3-15 Hz (cycles per second) up to 900 breaths
per minute for adults
⟶ Tidal volumes are less than dead space so HFOV relies on alternative
methods of gas exchange to promote removal of CO2 from the lung
⧫ Uses a constant distending pressure (mean airway pressure) with pressure
oscillations around the mean pressure
⧫ Maintains adequate alveolar recruitment
⧫ Active inspiration and active expiration
Describe history of HFOV?
⟰ 1972- Devolped by Lunkenheimer
⟰ 1975- Animal Trials
⟰ 1983- Used successfully in neonates and then Pediatrics
⟰ 1991- The 3100A High Frequency Oscillation Ventilator was first approved
for use in 1991 and is the only HFV approved for early intervention in the
treatment of neonatal respiratory failure.
⟰ 1995- FDA approval of Pediatrics, and 2001 for adults
Mechanisms of gas transport and gas
exchange
Convection
Turbulence
Bulk Convection
Convection- Diffusion
Pendelluft
Asymmetric velocity (inspiratory and expiratory)
Diffusion
Collateral Ventilation
Cardiogenic Mixing
https://youtu.be/btHyXaQ_lvE
Indications and Contraindications
Indications
Immature lungs or surfactant deficiency
Premature neonates with hyaline membrane disease
Meconium Aspiration Syndrome
ARDS
Diaphragmatic Hernia
PPHN
Bronchopulmonary fistula
Contraindications
Severe airflow obstruction
Intracranial hypertension
Initial settings on HFOV
Initial Settings
Optimal lung
•Set MAP 2-3 cmH2O above the MAP on conventional ventilation
•↑MAP in 1-2 cmH2O steps until oxygenation improves
volume strategy
(aim to maximise
•Set frequency to 10 Hz
recruitment of
Consider recruitment manoeuvres after discussion with consultant
alveoli).
Low volume
•Set MAP equal to the MAP on conventional ventilation
strategy
•Set frequency to 10 Hz
(aim to minimise lung •Adjust amplitude to get an adequate chest wall vibration.
trauma)
Adjustments
Poor Oxygenation
Increase FiO2
Over Oxygenation
Decrease FiO2
Increase MAP*
(1-2cmH2O)
Decrease MAP
(1-2cmH2O)
Under Ventilation
Over Ventilation
Increase Amplitude
Decrease Amplitude
Decrease Frequency** Increase Frequency**
(1-2Hz)
(1-2Hz)
if Amplitude Maximal
if Amplitude Minimal
Parameters
Flow >8
MAP >20
Amplitude >20- 100
I:E
Frequency – 5-20
FiO2
Tidal Volume
Suctioning
●
Indicated for
●
diminished Chest wall movement
●
Elevated Co2 or worsening oxygenation
●
ET obstruction
●
Visible or audible secretions in the airway
●
Always press the STOP button, and suction quickly.
●
C/I –
●
avoid 1st 24 hours
Weaning
●
Reduce FiO2 <40% before weaning MAP
●
Reduce MAP (1-2 cm H2O when chest radiograph shows evidence of over
inflation
●
Frequency amplitude in 2-4 cm H2O increments
●
Discontinue weaning when MAP 8-10 and amplitude 20-25
Important Considerations
🔺 Perform thorough suction before connecting to the oscillator
🔺 Closed system suction catheter
🔺 Avoid disconnection from the ventilator
🔺 Check for changes in pitch/rhythm of delivered breaths
🔺 Check chest wiggle
🔺 Always humidify gases
🔺 Obtain blood gases and CXR 2 hours after HFOV commencement and at
least daily
Complications
Hypotension
Pneumothorax
Endotracheal tube obstruction
Intraventricular hemorrhage (high MAP)
Which ventilators utilize HFOV?
CareFusion 3100A- for neonates
and pediatrics less than 35 kg
3100B- for adults and children
weighing more than 35 kg
SLE2000 Infant Ventilator by SLE
●
Acutronic FABIAN
●
https://www.youtube.com/watch?v=X
o8_4PEUDT4
Babylog 8000 by Drager
Which ventilators utilize HFOV?
Infant Star 950 by Soma Technology
Positive and negatives regarding it?
Positive
1. Used for lung protective ventilation - HFOV is more lung protective than the best
application of conventional ventilation
a. supports gas exchange with small Vt
b. improved alveolar recruitment
c. decreased inflammation
2.
Used for severe hypoxemia
Negative
1. There is not strong evidence
a. There are only a few studies on HFOV on its effect on alveolar inflammation
b. HFOV was used as a “rescue therapy” in “failed conventional ventilation,” despite
“rescue” a high percentage of patients died
2.
Cost
a. Expensive equipment and costs to train
b. hard to justify from an economic standpoint
3.
Need for sedation and paralysis
a. Paralysis can cause ICU acquired muscle weakness
b. Sedation may delay weaning
3. Safety
a. increased occlusion of pulmonary arterial pressure
b. decreased stroke volume
c. risk of pneumothorax
d. risk of barotrauma
What does research say in terms of
effectiveness?
2002- A randomized control study concluded that high-frequency
oscillation is a safe and effective mode of ventilation for the treatment of
acute respiratory distress syndrome in adults.
2006 - HFOV was used as a rescue therapy in very sick patients with
refractory hypoxemia, and improvement in oxygenation was observed
after 24 hours of this technique. HFOV is a reasonable alternative when a
protective lung strategy could not be achieved on conventional ventilation.
2012 - High frequency oscillatory ventilation was associated with better
early oxygenation and shorter hospital stay compared to synchronized
intermittent mandatory ventilation in preterm neonates with hyaline
membrane disease
2015- Compared with CV, the use of HFOV in ARDS was not associated
with a significant reduction in mortality. But the physiologic parameters of
patients in HFOV group were better than those in the CV group.
Question
●
ABG
●
pH = 7.26
●
CO2 = 64
●
O2 = 60
●
HCO2 = 28
1)Interpret the ABG
2) What changes would you make on the HFOV?
Questions
●
What is the difference between the Carefusion 3100A and 3100B?
●
What are some disease treated with HFOV?
●
1Hz = how many bpm.
Questions
●
What does MAP have an effect on?
●
What does Delta P (amplitude) have an effect on?
●
What is PPHN?
References
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Donn, S. (2012). High Frequency Oscillatory Ventilation. In Manual of neonatal respiratory care (3rd ed.). New York:
Springer.
●
Fessler, H, MD (2007). Does high frequency ventilation offer benefits over conventional ventilation in adult patients with
acute respiratory distress syndrome?
●
Jonathan M. Klein, MD, Management Strategies with High Frequency Oscillatory Ventilation (HFOV) in Neonates Using
the SensorMedics 3100A High Frequency Oscillatory Ventilator, 2015
●
http://www.uichildrens.org/childrens-content.aspx?id=234517
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Pillow, Jane J PhD. (2005). High frequency oscillatory ventilation: Mechanism of gas exchange and lung mechanics.
●
S. P. Stawicki, MD, Munish Goyal, MD, and Babak Sarani, MD, FACS, High-Frequency Oscillatory Ventilation (HFOV) and
Airway Pressure Release Ventilation (APRV): A Practical Guidem, Jurnal of Intensive Care mediicin 2009.
●
Stephen Derdak, Sangeeta Mehta, Thomas E. Stewart, Terry Smith, Mark Rogers, Timothy G. Buchman, Brian Carlin,
Stuart Lowson, John Granton, and the Multicenter Oscillatory Ventilation for Acute Respiratory Distress Syndrome Trial
(MOAT) Study Investigators High-Frequency Oscillatory Ventilation for Acute Respiratory Distress Syndrome in Adults A
Randomized, Controlled Trial, ATS Journal 2002.
●
Javier D Finkielman1, Ognjen Gajic2, J Christopher Farmer2, Bekele Afessa2 and Rolf D Hubmayr2*The initial Mayo Clinic
experience using high-frequency oscillatory ventilation for adult patients: a retrospective study, BMC2006.
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SN SINGH, GK MALIK, GP PRASHANTH, ANITA SINGH ANDMALA KUMARHigh Frequency Oscillatory Ventilation versus
Synchronized Intermittent Mandatory Ventilation in Preterm Neonates with Hyaline Membrane Disease: A Randomized
Controlled Trial, Inidan Pediatrics, 2012
●
Wang H, Sun T, Wan Y, Kan QThe effects of high frequency oscillation ventilation on patients with acute respiratory
distress syndrome: a Meta-analysis and sequential analysis of trial], Europe PubMed 2015