Getting the pressure right
Endotracheal tubes are life-saving devices for many patients, but respiratory therapists should be aware of key nuances related to the pressure of tubes and cuffs in order to maintain patient health and comfort. Pressure plays a big role in the care of ventilated patients and their ability to maintain health and recover from adverse events. Here are some key considerations for respiratory therapists to think about when striving to take the best possible care of their ventilated patients:
Select the right endotracheal tube (ET) cuff:
Materials matter when it comes to endotracheal tubes. Older ET tube cuffs were elliptical and made of polyvinyl chloride, according to an article in Airway Management. (1) Newer cuffs, made from polyurethane, are often barrel or teardrop shape, and much thinner than their older counterparts.(1) At just 7 microns thick, they are also thinner, compared to their older counterparts, which were between 50 and 80 microns (1). The thinner tubes are shown to seal more effectively and protect against aspiration, which may help prevent ventilator associated pneumonia (VAP) (2).
Get the pressure right:
Cuff pressure is as important as cuff materials in maintaining the health and comfort of ventilated patients. Under inflation can cause the patient to aspirate (3) fluids, and over inflation can cause tracheal ischemia (1), inadequate blood supply to an area due to a blockage of blood vessels by the tube itself. Thus, respiratory therapists should work to maintain proper cuff pressure (3) at all times through whatever monitoring methods work best.
Manage your monitor:
While there are a variety of methods to keep cuff pressure in a targeted range, from finger pressure to the minimal leak technique, a 2014 study in Respiratory Care found that a volume time-curve method of ventilation helped prevent post-intubation sore throat, reduced severity of cough, and less thoracic pain in surgical patients (4). Respiratory therapists will benefit from considering their options in pressure monitoring for best outcomes.
Consider patient position:
Patients are often moved to keep from developing skin lesions and to maintain bodily comfort. However, a 2014 study in the American Journal of Critical Care found that any body position changes, no matter how small, can negatively affect cuff pressure, (5) so be strategic about when and how you reposition patients.
- Grzeskowiak, Mark. Protecting the Airway, Protecting the Patient. Airway Management. [Cited Feb. 2015]. http://www.rtmagazine.com/2015/02/protecting-airway-protecting-patient/
- Lorente L. Influence of an endotracheal tube with polyurethane cuff and subglottic secretion drainage on pneumonia. Am J Respir Crit are Med. 2007 Dec 1:176(11): 1079-83. Epub 2007. Sep 13. https://www.atsjournals.org/doi/abs/10.1164/rccm.200705-761OC?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed
- Motoyama, A. Changes in endotracheal tube cuff pressure in mechanically ventilated adult patients. J Intensive Care. 2014 Jan 31. Doi: 10.1186/2052-049-2-7. https://jintensivecare.biomedcentral.com/track/pdf/10.1186/2052-0492-2-7
- Bolzan, DW. Clinical use of the volume-time curve for endotracheal tube cuff management. Respir Care. 2014 Nov;59(11): 1628-35. http://rc.rcjournal.com/content/59/11/1628.short
- Lizy, C. Cuff pressure of endotracheal tubes after changes in body position in critically ill patients treated with mechanical ventilation. Am J Crit Care. 2014 Jan;23(1):e 1-8. http://ajcc.aacnjournals.org/content/23/1/e1.long