Endotracheal tube size selection in critically ill patients: a 4-year single-center experience in Saudi Arabia

BACKGROUND:
Intubation is a critical aspect of airway management and supportive care for intensive care unit (ICU) patients. Inappropriate size of endotracheal tubes (ETT) affects the patient's airway, it is crucial to choose an appropriate size for each patient.


OBJECTIVES:
This study aimed to assess current practices of ETT size.


SELECTION
for adult ICU patients and to explore factors associated with it.


DESIGN AND SETTINGS:
Single-center, retrospective cohort study at King Fahad Hospital of the University, Saudi Arabia.


PATIENTS AND METHODS:
A retrospective review was conducted for adult patients admitted to ICU from January 2020 to January 2024 at King Fahad Hospital of the University. Inclusion criteria included patients aged 18 years or older, underwent intubation and was followed by tracheostomy. Those with missing data, had laryngeal or thyroid masses, had upper airway obstruction by any cause and upper airway surgery were excluded.


MAIN OUTCOME AND MEASURES:
The primary outcome was compliance of ETT size selection with established guidelines. Secondary outcomes included associations between ETT size (mm), patient demographics and intubation indications.


RESULTS:

A total of 228 ICU patients were analysed [mean (standard deviation) age of 61.8 (19.6) years]. The median internal diameter of the ETT size was 7.5 mm, with neurological causes being the most common indication for intubation. ETT size showed a significant positive correlation with height (rs=.341;
P
<.001) and weight (rs=0.190; p=0.004), but not with body mass index (rs=.050;
P
=.456). In multivariable analysis, larger ETT size was significantly associated with male sex (adjusted odds ratio, aOR 2.38, 95% confidence interval, CI 1.12–5.05), pulmonary indication for intubation (aOR 2.31, 95% CI 1.10–4.86), older age (aOR 1.20 per 10 years, 95% CI 1.02–1.42), and height (aOR 1.95 per 10 cm, 95% CI 1.20–3.16), whereas weight was not independently associated after adjustment (aOR 1.04 per 10 kg, 95% CI 0.85–1.26). Overall, 77% of ETT size selection did not comply with height-based guidelines.



CONCLUSIONS:
No standardized ETT size selection guidelines were followed for adult ICU patients. Male sex, height, older age, and pulmonary indication were independent predictors of larger ETT size, supporting the implementation of more structured, height-informed ETT sizing protocols.