Post-Intubation Tracheal Stenosis

Post-Intubation Tracheal Stenosis

There has been quite a bit of research done on post-intubation injuries caused by the pressure of the endotracheal tube cuff. This is something that has been addressed by a few EMS agencies. My agency implemented a protocol based on the research about two years ago:

Based on what size ET tube you use. If you use a 9.0 tube, inflate with 9cc of air, 8.0 tube with 8cc of air and so on and so forth. This is not full proof, but it does make you think about how much air you are inflating with instead of just pumping in the full 10cc every time.

Here is some of the research done recently:

Pubmed [1]
Cuff overinflation and endotracheal tube obstruction: case report and experimental study.
BACKGROUND: Initiated by a clinical case of critical endotracheal tube (ETT) obstruction, we aimed to determine factors that potentially contribute to the development of endotracheal tube obstruction by its inflated cuff. Prehospital climate and storage conditions were simulated. METHODS: Five different disposable ETTs (6.0, 7.0, and 8.0 mm inner diameter) were exposed to ambient outside temperature for 13 months. In addition, every second of these tubes was mechanically stressed by clamping its cuffed end between the covers of a metal emergency case for 10 min. Then, all tubes were heated up to normal body temperature, placed within the cock of a syringe, followed by stepwise inflation of their cuffs to pressures of 3 kPa and > or =12 kPa, respectively. The inner lumen of the ETT was checked with the naked eye for any obstruction caused by the external cuff pressure. RESULTS: Neither in tubes that were exposed to ambient temperature (range: -12 degrees C to +44 degrees C) nor in those that were also clamped, visible obstruction by inflated cuffs was detected at any of the two cuff pressure levels. CONCLUSIONS: We could not demonstrate a critical obstruction of an ETT by its inflated cuff, neither when the cuff was over-inflated to a pressure of 12 kPa or higher, nor in ETTs that had been exposed to unfavorable storage conditions and significant mechanical stress.

Pubmed [2]
Endotracheal Tube Intracuff Pressure During Helicopter Transport.
STUDY OBJECTIVE: We evaluate changes in endotracheal tube intracuff pressures among intubated patients during aeromedical transport. We determine whether intracuff pressures exceed 30 cm H(2)O during aeromedical transport. METHODS: During a 12-month period, a helicopter-based rescue team prospectively recorded intracuff pressures of mechanically ventilated patients before takeoff and as soon as the maximum flight level was reached. With a commercially available pressure manometer, intracuff pressure was adjusted to /=30 cm H(2)O, 72% had intracuff pressures >/=50 cm H(2)O, and 20% even had intracuff pressures >/=80 cm H(2)O. CONCLUSION: Endotracheal cuff pressure during transport frequently exceeded 30 cm H(2)O during aeromedical transport. Hospital and out-of-hospital practitioners should measure and adjust endotracheal cuff pressures before and during flight. Copyright © 2010 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

Pubmed [3]
Endotracheal tube cuff pressures in patients intubated before transport.
INTRODUCTION: Prolonged endotracheal tube cuff pressures (ETTCPs) greater than 30 cm H(2)O cause complications ranging from sore throat to rare cases of tracheoesophageal fistula. In a series of patients, we sought to determine the proportion of patients with overinflated cuffs and to determine whether overinflation was associated with demographics, diagnostic category, or intubator credentials. METHODS: Between July 2007 and April 2008, we measured cuff pressures on a convenience sample of patients drawn from 2 groups. The "helicopter group" had pressure measured before transport by a single aeromedical transport service. The "hospital group" had pressure measured upon arrival to 1 of 2 emergency departments after being intubated before transport. RESULTS: Three hundred patients aged 4 to 92 years (median, 57) were studied: 59.7% were male; and diagnostic categories were neurologic (33.7%), trauma (32.7%), cardiac (12.7%), and general medical/surgical (21.0%). Intubation occurred 1 to 28 000 minutes before ETTCP assessment (median, 60). Endotracheal tube cuff pressure was greater than 30 cm H(2)O in 64.7% and ranged from 10 to 180 (median, 40). Forty-nine percent of patients had ETTCP greater than 40 cm H(2)O. There was no association between ETTCP and age group, sex, diagnostic category, ETT size, time between intubation and ETTCP assessment, or intubator credentials. CONCLUSIONS: The most compelling results of the study are the high rates of elevated ETTCPs. Furthermore, there were no clear risk factors for elevated ETTCP. Although the risk of elevated ETTCP in the prehospital to acute care time frame is unclear, it seems reasonable to measure ETTCP after intubation in all patients.

Pubmed [4]
Intubation-induced tracheal stenosis -- the urgent need for permanent solution.
The most common site for the occurrence of intubation-induced tracheal damage is at the area in contact with the inflatable cuff. After the change from high-pressure to low-pressure cuffs, major tracheal lesions still continue to occur. This is a case of tracheal stenosis that occurred after 7 days of intubation with standard cuffed tube whose cuff pressure was assessed by subjective means. Three weeks later, patient was in need of reintubation, the trachea was found to be stenotic at the site of the previous tube cuff. Emergency tracheostomy had to be performed and computed axial tomography (CT) confirmed the tracheal stenosis. A month later, the patient had another cardiac arrest from which he did not recover. Our message in this report is to throw light and alert clinicians involved in tracheal intubation, of the presence of the Lanz endotracheal tube whose pilot balloon is designed to automatically regulate the intra-cuff pressure and thus prevent the occurrence of tracheal stenosis due to high pressure. We strongly recommend the presence of Lanz tracheal tubes as standard emergency equipment in intensive care settings and in any situation in which cuff pressure is likely to increase. - Link to related article.


Firefighter/Paramedic said...

Something that I've never thought about before. Thanks for the post.

Adam Thompson, EMT-P said...

You're welcome. I bet there are others who have never considered this an issue before.

Christopher said...

I've heard about appropriate cuff pressures, but not to the degree these articles go into. Going to read these when I get into work.