HFOV

Question 1

What is the strategy that HFOV uses?

Answer 1

“Open lung” strategy
High rate -up to 900bpm
Very low tidal volume  
Alveoli are recruited with MAP
With lower peak pressures than conventional

Can potentially reduce lung injury
Prevent or manage pulmonary air leaks

Help Oxygenate

Question 2

What knobs control oxygenation and MAP on HFOV?

Answer 2

Bias flow
Mean Pressure adjustment
Mean Pressure limit

Question 3

What controls ventilation on HFOV?

Answer 3

Power
Frequency
I-time %

Question 4

How much AMP should you set for an Infant or adult on HFOV?

Answer 4

WIGGLE
Infants wiggle chest,
Peds should wiggle to groin, Adults to mid thigh

Question 5

What does decreasing Frequency do for Pac02?

Answer 5

Decreased frequency = increase Vt = decrease CO2

Question 6

On the CXR, to what rib should you see lung inflation on HFOV?

Answer 6

Adjust to a diaphram level of ~8.5 ribs

Question 7

What should your starting MAP be on HFOV?

Answer 7

Start with MAP 2-6 greater than on mechanical ventilation

For patient with air leak, start with similar MAP

Question 8

What alternatives do you have to decreasing C02 with patients on HFOV?

Answer 8

Decreasing cuff pressure

allow CO2 rich gas to escape around the ET tube

To maintain MAP, fresh gas is added from Vent

Question 9

Weaning from HFOV to Conventional Vent

Answer 9

Wean to Conventional Ventilation when:
MAP: 10-12 infants, <20 for Adults
AMP: <30
FiO2 < 50%, sats > 90%
ABGs Stable
Patient is stable during suctioning
Patient is hemodynamically stable
For adults:  Some advocate PCV with 1:1, PEEP 10, Vt 6-10ml/kg

Question 10

What should breath sounds be like in HFOV?

Answer 10

Breath sounds - identifying the normal “breath “ sounds is difficult, since HFOV is not ventilation with a bulk flow of gas through the airway.

Listen to the “intensity or sound” that the piston makes, it should be equal through out.

If not the same sound, re-assess the patient to determine if a chest x-ray is necessary at this time

Question 11

What happens if in HFOV you have no chest wiggle factor?

Answer 11

CWF absent or diminished is a clinical sign that the airway or ET tube is obstructed.

Question 12

What happens if in HFOV you have chest wiggle factor only on one side?

Answer 12

CWF present on one side only is an indication that the ET tube has slipped down a mainstem bronchus or a pneumothorax has occurred.

Check the position of the ET tube or obtain a CXR.

Question 13

What are complications to HFOV?

Answer 13

Air Trapping from Airway Obstruction (Asthma, Merconium Aspiration)
Intraventricular Hemorrage

Question 14

How is Frequency Calculated in HFOV?

Answer 14

1 Hz = 60 Bpm

Question 15

In HFOV, inspiration and expiration is?

Answer 15

ACTIVE

Question 16

How do you affect Pa02 in HFOV?

Answer 16

Adjust MAP, FiO2

MAP and PaO2 are directly related
MAP = O2 unless over distended

Question 17

What are the initial frequency settings?

Answer 17

3-15 HZ (180-900 bpm)
< 10 kg: 10-12 Hz
10-20 kg: 8-10 Hz
20-40 kg: 6-8 Hz
 >40 kg: 3-5 Hz