Jet Ventilation

Last modified: 04 May 2023, 9:01:46 AM AEST

Gems1 / 9

2 types
- low frequency = LFJV
- high frequency = HFJV
both use high-pressure O2 sources
- interrupted by mechanical / electronic devices
- tidal volume generated by injected volume + entrained volume
  - entrainment due to Venturi effect
must use TIVA
maybe supraglottic / infraglottic / transtracheal
look for chest wall movement

Contraindications2 / 9

difficulty maintaining oxygenation / ventilation
- morbid obesity
- stiff thorax
- restrictive / obstructive lung disease

Risks / disadvantages3 / 9

Devices (LFJV)4 / 9

Supraglottic
- Jet cannula
  - attached to proximal end of surgical laryngoscope
  - lined up with glottic inlet
  - Adv = optimal surgical access
Subglottic
- Jet cannula = Mistral catheter, Hunsaker Mon-Jet tube
  - Mallinkrodt insufflator = endotracheal devices
    - petals to hold tube centrally in lumen
  - Benjet = has petals
  - Monjet = has basket
  - Inserted below vocal cords under direct vision
Transtracheal
- Cannula
  - inserted through cricothyroid membrane

Technique (LFJV)5 / 9

less than 60 jets per minute
start with low pressure
- start at 1 bar
- Range = 1-4 bar
- around 30 psi / 2.5 bar
- adults = start at 20 psi
- children = start at 5-10 psi
- device will have ranges for paediatric / adult pressure limits
hand-held devices (see above)
O2 delivered at up to 400 kPa = 4 atm
- max = 50 psi = 3.4 atm
exhalation via passive recoil of chest
- hand on chest and feel chest deflate before insufflating again
requires LOWER RR (8-10) to avoid air-trapping
- tolerate hypercarbia
- priority is oxygenation
Count 1-2-3-4
- 1 = Inflate
- 2-3-4 = Passive recoil
Do not inflate when the airway is instrumented
- The instruments obstruct the airway and jet ventilation will cause barotrauma

Technique (HFJV)6 / 9

more than 60 jets per minute
commercial / specialized ventilators capable of producing the high pressure, low volume breaths
eg. Monsoon
1-10 Hz heated humidified jets = 1-10 jets per second
Time-cycled, pressure-limited ventilation
PEEP generated via breath-stacking

Anaesthesia7 / 9

Desaturation8 / 9

References9 / 9