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The 'best fit' endotracheal tube in children --comparison of four formulae
A Turkistani1, K M Abdullah, B Delvi
1College of Medicine, King Saud University, Riyadh 11461, P.O. Box: 2925, Riyadh, SA.
Insights
The age-based and 5th fingernail width methods accurately predict endotracheal tube size in children, outperforming length-based and multivariate formulas. These findings aid in selecting the appropriate uncuffed endotracheal tube for pediatric anesthesia.
Area of Science:
- Pediatric Anesthesiology
- Airway Management
- Medical Device Sizing
Background:
- Uncuffed endotracheal tubes are commonly used in pediatric anesthesia.
- Accurate sizing of endotracheal tubes is crucial for patient safety and effective ventilation.
- Several formulas exist to predict the appropriate endotracheal tube size based on age, length, weight, or external measurements.
Purpose of the Study:
- To prospectively compare the accuracy of different formulas for predicting endotracheal tube size in children.
- To evaluate the 'best fit' endotracheal tube size against age-based, length-based, multivariate, and 5th fingernail width-based predictions.
Main Methods:
- 27 boys and 23 girls (2-10 years old) undergoing general anesthesia were enrolled.
- The 'best fit' endotracheal tube internal diameter (ID) was determined by pediatric anesthesiologists.
- This 'best fit' ID was compared to predictions from age-based, length-based, multivariate, and 5th fingernail width formulas.
Main Results:
- Mean IDs for 'best fit', age-based, length-based, multivariate, and 5th fingernail methods were 5.31, 5.54, 5.82, 5.71, and 5.43 mm, respectively.
- The age-based and 5th fingernail width methods showed closer agreement with the 'best fit' size compared to other formulas.
Conclusions:
- Age-based and 5th fingernail width predictions are more accurate for selecting endotracheal tube size in pediatric patients.
- These methods offer better mean values and case matching compared to length-based and multivariate formulas.
- The findings support the use of age and 5th fingernail width for improved endotracheal tube selection in pediatric anesthesia.
Background:
Uncuffed endotracheal tubes are still being recommended by most pediatric of anesthetists at our Institutes. Different algorithms and formulae have been proposed to choose the best-fitting size of the tracheal tube. The most widely accepted is related to the age of the child [inner diameter [ID] in mm = (age in yr/4) + 4; the second is a body, length-related formula (ID in mm = 2 + height in cm/30); the third, a multivariate formula (ID in mm = 2.44 + age in yr x 0.1 + height in cm x 0.02 + weight in kg x 0.016]5; the fourth, the width of the 5th fingernail is used for ID prediction of the ETT (ID in mm = maximum width of the 5th fingernail). The primary endpoint of this prospective study was to compare the size of the 'best fit' tracheal tube with the size predicted using each of the above mentioned formulae.
Patients And Methods:
With Institutional Ethics Committee approval and parental consent, 27 boys, 23 girls, ASA I-III, 2-10 years, scheduled for different surgical procedures requiring general anesthesia and endotracheal intubation, were enrolled in the study. The size of 'best fit' endotracheal tubes in those children were compared. The internal diameter considered the 'best fit' by the attending pediatric anesthesiologist was compared to age-based, length-based, multivariate-based and 5th fingernail width-based formulae. For all tests, P < 0.05 was considered to be statistically significant.
Results:
The mean (SD) IDs for the 'best fit', age-based, length-based, multivariate and 5th fingernail techniques were 5.31 (0.691), 5.54 (0.622), 5.82 (0.572), 5.71 (0.67) and 5.43 (0.821) mm, respectively.
Conclusions:
The age-based and 5th fingernail width-based predictions of ETT size are more accurate than length-based and multivariate-based formulae in terms of mean value and case matching.
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