The debate over uncuffed versus cuffed endotracheal tubes (ETTs) is long-standing. This week, one paediatric critical care unit published the results of its experience introducing cuffed ETTs in a paper published in Pediatric Anesthesia.
What’s the background?
Many intensive care units use uncuffed ETTs in neonates due to concerns about cuff-related trauma and subglottic stenosis. The estimated incidence of ETT-related subglottic stenosis (SGS) ranges from 0.3-11%.
The benefits of a cuffed tube are thought to be accurate ETCO2 monitoring, protection from aspiration, fewer tube changes due to air leaks, and continuous lung recruitment.
The concerns about cuffed tubes are that they cause increased trauma and that this trauma can lead to erosion, infection, cricoid perichondritis, and, ultimately, subglottic stenosis.
The author introduced the use of Microcuff ETTs into their unit, hypothesizing that it may lead to less ulceration, chondritis, and fibrosis in the subglottic space. Microcuffs are a specific type of ETT (low-pressure, high-volume), but the smallest type has a 3.0mm internal diameter, which is not recommended for neonates less than 3kg.
Who were the patients?
This was a retrospective analysis of all patients admitted to the Paediatric Critical Care Unit in Australia over five years.
Patients were included if they also had a microlaryngobronchoscopy (MLB) procedure.
Patients were excluded if they were >18 years old, had congenital SGS, had previous airway surgery, or had a previous SGS diagnosis.
What were the outcomes?
MLB reports were reviewed to look for findings consistent with clinically significant acquired endotracheal tube-related pathology (within six months of intubation).
Demographics, including age, sex, prematurity, comorbidities, duration of ventilation, number of intubations, and duration of admission, were analyzed.
What did they find?
There were 5309 PCCU admissions over the five years and 61% required intubation.
297 patients had an MLB.
23 children (0.68% of all intubations) had clinically significant ETT-related pathology: 8 had acquired sub-glottic stenosis, and 15 had other ETT-related pathology (granulomas, ulcers, or cysts).
5 of the 8 children with sub-glottic stenosis required tracheostomies.
All those who required surgical correction of the SGS were ex-prem neonates who had received invasive ventilation in a NICU with an uncuffed tube before admission to PCCU.
What conclusions did they draw?
They demonstrated a low incidence (but high morbidity) of acquired sub-glottic stenosis.
There were a few issues around the conclusions drawn:
- The authors state, ‘there was no single case of de novo clinically significant acquired SGS with the use of cuffed ETTs‘. I’m not sure this is a fair conclusion, as there were 8 cases of acquired SGS. Yes, these cases all had an uncuffed tube initially in NICU, but they also had a cuffed tube in PCCU.
- It would be good to compare the rates of SGS before introducing Microcuff ETTs with these rates after its introduction—this would help to see whether rates have increased. It would also be helpful to look at the neonatal group, as this study reports the overall percentage of SGS in all patients and then draws conclusions about its safety in neonates.
However, in spite of concerns about the use of cuffed tubes, no study has previously shown that cuffed ETTs lead to a higher incidence of SGS than uncuffed ETTs. This is an interesting paper that will open the discussion about the use of cuffed ETTs in neonates.
If you want to learn more about tiny tubes, catch this talk by Shabs Rajapaksa from DFTB18.
Expert Opinion – Eric Levi, Consultant Paediatric Otolaryngologist
I would love to see other data to enhance this paper:Â a comparison of rates of SGS prior to cuffed tubes and a comparison of rates of SGS in other patients who did have an uncuffed tube but did not develop SGS. Surely, in the 3000 or so intubations, there would have been others who were also tubed with uncuffed tubes and yet did not develop any tube-related pathology.
Although this is not a perfect paper, I think the authors are onto something, and they are adding to the body of knowledge by suggesting that in their cohort, cuffed tubes are not associated with SGS.
One of the key determinants is the careful management inflation pressures of the cuff Both over and under inflation of the cuff increase risk of subglottic pathology.
Now we have low pressure cuffs the risk of sub-glottic stenosis is low. Uncuffed tubes appear to be more risky
So, in your opinion, or based on what you usually do at your unit, do you feel/perceive that cuffed tubes are more dangerous?
Inflate*
If mistakenly cuffe was not inflammed. Wht could be the hazards to patient
Cuffed tubes are usually half a size smaller than uncuffed tubes. The main issue would be one of a cuff leak and inadequate ventilation/oxygenation as well as the possibility of aspiration.