Methods
- Minimal Leak Technique (MLT): “air inflation of the tube cuff until any leak stops, then a amount of air is slowly removed until a slight leak is observed at peak inflation pressure” (Burns, 2007).
- Minimal Occluding Volume (MOV): “air inflation of the tube cuff until the air flow heard escaping around the cuff during a positive pressure breath ceases” (Burns, 2007).
- Safe pressure <25 cmH2O ( although ranges 20 – 30 cmH2O are normally considered safe) – check your local policy.
- Continuous cuff pressure management/monitoring systems (see below in Technology).
Purpose
- Maintain a seal around the airway (ETT/Trache) for positive pressure ventilation
- Prevention of Ventilator Associated Pneumonia (VAP)
- Protect the airway from aspiration of gastric contents.
Risk Prevention Aims
To create the seal in the airway without exerting unnecessary high pressure on the trachea which may compromise mucosal circulation, potentially causing necrosis, tracheal rupture, necrosis and stenosis, tracheo-oesophageal fistula, tracheomalacia and recurrent laryngeal nerve palsy (Harvie et al, 2016). Hence why a ‘one standard pressure’ fits all approach may not work due to varying trachea anatomy.
Technology
Uniform cuff pressure management/monitoring devices such as Intellicuff may help provide optimal cuff pressure and prevent secondary issues (Note: no disclaimer of interest on any of these products discussed).
Clinical
Follow your unit/hospital airway guideline.
Process
Other Factors Impacting on Cuff Pressure:
- patient position
- head position
- cuff position
- cuff volume
- temperature
Caution Note
Cuff pressures below 20 cmH2O have been shown to increase the risk of microaspiration, with a concomitant increase shown in ventilator-associated pneumonia.
Continually need for higher cuff pressures – needs review for airway position and/or potential cuff leak.
Top Tip
Sharp implements: when removing old ETT tapes (yes, you should use forceps to untie but sometimes you just cant get those knots undone and have to snip the tapes) or shaving a patient, remember to move the pilot balloon on top of ETT or safely out of the way. If it is cut, hit the emergency buzzer, and some things you can do until the intubation team are ready:
- 100% oxygen to the patient- monitor O2 sats and CO2 level,
- Forceps to clamp the pilot line,
- A needle down the inside of the pilot line can then be attached to a 3 way tap and syringe to reinflate the pilot balloon,
- If you have leak compensation on the ventilator you could try to maintain peep using this setting,
- Apologise- accidents actually do occur, reflect and move on.
References
Burns, S. M. (Ed.). (2007). AACN protocols for practice: care of mechanically ventilated patients. AACN. Jones & Bartlett Learning.
Harvie, D. A., Darvall, J. N., Dodd, M., De La Cruz, A., Tacey, M., D’Costa, R. L., & Ward, D. (2016). The minimal leak test technique for endotracheal cuff maintenance. Anaesthesia and intensive care, 44(5), 599-604.
Jaillette, E., Martin-Loeches, I., Artigas, A., & Nseir, S. (2014). Optimal care and design of the tracheal cuff in the critically ill patient. Annals of Intensive Care, 4(1), 7.